[PATCH v4 00/34] Split ptdesc from struct page

[PATCH v4 00/34] Split ptdesc from struct page

[Vishal Moola (Oracle)]

The MM subsystem is trying to shrink struct page. This patchset
introduces a memory descriptor for page table tracking - struct ptdesc.

This patchset introduces ptdesc, splits ptdesc from struct page, and
converts many callers of page table constructor/destructors to use ptdescs.

Ptdesc is a foundation to further standardize page tables, and eventually
allow for dynamic allocation of page tables independent of struct page.
However, the use of pages for page table tracking is quite deeply
ingrained and varied across archictectures, so there is still a lot of
work to be done before that can happen.

This is rebased on next-20230609.

v4:
  Got more Acked-bys
  Fixed m68k compilation issue
  Dropped unnecessary casts
  Cleanup some fields in struct ptdesc

Vishal Moola (Oracle) (34):
  mm: Add PAGE_TYPE_OP folio functions
  s390: Use _pt_s390_gaddr for gmap address tracking
  s390: Use pt_frag_refcount for pagetables
  pgtable: Create struct ptdesc
  mm: add utility functions for ptdesc
  mm: Convert pmd_pgtable_page() to pmd_ptdesc()
  mm: Convert ptlock_alloc() to use ptdescs
  mm: Convert ptlock_ptr() to use ptdescs
  mm: Convert pmd_ptlock_init() to use ptdescs
  mm: Convert ptlock_init() to use ptdescs
  mm: Convert pmd_ptlock_free() to use ptdescs
  mm: Convert ptlock_free() to use ptdescs
  mm: Create ptdesc equivalents for pgtable_{pte,pmd}_page_{ctor,dtor}
  powerpc: Convert various functions to use ptdescs
  x86: Convert various functions to use ptdescs
  s390: Convert various gmap functions to use ptdescs
  s390: Convert various pgalloc functions to use ptdescs
  mm: Remove page table members from struct page
  pgalloc: Convert various functions to use ptdescs
  arm: Convert various functions to use ptdescs
  arm64: Convert various functions to use ptdescs
  csky: Convert __pte_free_tlb() to use ptdescs
  hexagon: Convert __pte_free_tlb() to use ptdescs
  loongarch: Convert various functions to use ptdescs
  m68k: Convert various functions to use ptdescs
  mips: Convert various functions to use ptdescs
  nios2: Convert __pte_free_tlb() to use ptdescs
  openrisc: Convert __pte_free_tlb() to use ptdescs
  riscv: Convert alloc_{pmd, pte}_late() to use ptdescs
  sh: Convert pte_free_tlb() to use ptdescs
  sparc64: Convert various functions to use ptdescs
  sparc: Convert pgtable_pte_page_{ctor, dtor}() to ptdesc equivalents
  um: Convert {pmd, pte}_free_tlb() to use ptdescs
  mm: Remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers

 Documentation/mm/split_page_table_lock.rst    |  12 +-
 .../zh_CN/mm/split_page_table_lock.rst        |  14 +-
 arch/arm/include/asm/tlb.h                    |  12 +-
 arch/arm/mm/mmu.c                             |   6 +-
 arch/arm64/include/asm/tlb.h                  |  14 +-
 arch/arm64/mm/mmu.c                           |   7 +-
 arch/csky/include/asm/pgalloc.h               |   4 +-
 arch/hexagon/include/asm/pgalloc.h            |   8 +-
 arch/loongarch/include/asm/pgalloc.h          |  27 ++-
 arch/loongarch/mm/pgtable.c                   |   7 +-
 arch/m68k/include/asm/mcf_pgalloc.h           |  41 ++--
 arch/m68k/include/asm/sun3_pgalloc.h          |   8 +-
 arch/m68k/mm/motorola.c                       |   4 +-
 arch/mips/include/asm/pgalloc.h               |  31 +--
 arch/mips/mm/pgtable.c                        |   7 +-
 arch/nios2/include/asm/pgalloc.h              |   8 +-
 arch/openrisc/include/asm/pgalloc.h           |   8 +-
 arch/powerpc/mm/book3s64/mmu_context.c        |  10 +-
 arch/powerpc/mm/book3s64/pgtable.c            |  32 +--
 arch/powerpc/mm/pgtable-frag.c                |  46 ++--
 arch/riscv/include/asm/pgalloc.h              |   8 +-
 arch/riscv/mm/init.c                          |  16 +-
 arch/s390/include/asm/pgalloc.h               |   4 +-
 arch/s390/include/asm/tlb.h                   |   4 +-
 arch/s390/mm/gmap.c                           | 222 +++++++++++-------
 arch/s390/mm/pgalloc.c                        | 126 +++++-----
 arch/sh/include/asm/pgalloc.h                 |   9 +-
 arch/sparc/mm/init_64.c                       |  17 +-
 arch/sparc/mm/srmmu.c                         |   5 +-
 arch/um/include/asm/pgalloc.h                 |  18 +-
 arch/x86/mm/pgtable.c                         |  46 ++--
 arch/x86/xen/mmu_pv.c                         |   2 +-
 include/asm-generic/pgalloc.h                 |  62 +++--
 include/asm-generic/tlb.h                     |  11 +
 include/linux/mm.h                            | 155 ++++++++----
 include/linux/mm_types.h                      |  14 --
 include/linux/page-flags.h                    |  20 +-
 include/linux/pgtable.h                       |  60 +++++
 mm/memory.c                                   |   8 +-
 39 files changed, 664 insertions(+), 449 deletions(-)

-- 
2.40.1

[PATCH v4 01/34] mm: Add PAGE_TYPE_OP folio functions

[Vishal Moola (Oracle)]

No folio equivalents for page type operations have been defined, so
define them for later folio conversions.

Also changes the Page##uname macros to take in const struct page* since
we only read the memory here.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/page-flags.h | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 92a2063a0a23..e99a616b9bcd 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -908,6 +908,8 @@ static inline bool is_page_hwpoison(struct page *page)
 
 #define PageType(page, flag)						\
 	((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
+#define folio_test_type(folio, flag)					\
+	((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
 
 static inline int page_type_has_type(unsigned int page_type)
 {
@@ -920,20 +922,34 @@ static inline int page_has_type(struct page *page)
 }
 
 #define PAGE_TYPE_OPS(uname, lname)					\
-static __always_inline int Page##uname(struct page *page)		\
+static __always_inline int Page##uname(const struct page *page)		\
 {									\
 	return PageType(page, PG_##lname);				\
 }									\
+static __always_inline int folio_test_##lname(const struct folio *folio)\
+{									\
+	return folio_test_type(folio, PG_##lname);			\
+}									\
 static __always_inline void __SetPage##uname(struct page *page)		\
 {									\
 	VM_BUG_ON_PAGE(!PageType(page, 0), page);			\
 	page->page_type &= ~PG_##lname;					\
 }									\
+static __always_inline void __folio_set_##lname(struct folio *folio)	\
+{									\
+	VM_BUG_ON_FOLIO(!folio_test_type(folio, 0), folio);		\
+	folio->page.page_type &= ~PG_##lname;				\
+}									\
 static __always_inline void __ClearPage##uname(struct page *page)	\
 {									\
 	VM_BUG_ON_PAGE(!Page##uname(page), page);			\
 	page->page_type |= PG_##lname;					\
-}
+}									\
+static __always_inline void __folio_clear_##lname(struct folio *folio)	\
+{									\
+	VM_BUG_ON_FOLIO(!folio_test_##lname(folio), folio);		\
+	folio->page.page_type |= PG_##lname;				\
+}									\
 
 /*
  * PageBuddy() indicates that the page is free and in the buddy system
-- 
2.40.1

Re: [PATCH v4 01/34] mm: Add PAGE_TYPE_OP folio functions

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:50PM -0700, Vishal Moola (Oracle) wrote:
> No folio equivalents for page type operations have been defined, so
> define them for later folio conversions.
> 
> Also changes the Page##uname macros to take in const struct page* since
> we only read the memory here.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/page-flags.h | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
> index 92a2063a0a23..e99a616b9bcd 100644
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -908,6 +908,8 @@ static inline bool is_page_hwpoison(struct page *page)
>  
>  #define PageType(page, flag)						\
>  	((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
> +#define folio_test_type(folio, flag)					\
> +	((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
>  
>  static inline int page_type_has_type(unsigned int page_type)
>  {
> @@ -920,20 +922,34 @@ static inline int page_has_type(struct page *page)
>  }
>  
>  #define PAGE_TYPE_OPS(uname, lname)					\
> -static __always_inline int Page##uname(struct page *page)		\
> +static __always_inline int Page##uname(const struct page *page)		\
>  {									\
>  	return PageType(page, PG_##lname);				\
>  }									\
> +static __always_inline int folio_test_##lname(const struct folio *folio)\
> +{									\
> +	return folio_test_type(folio, PG_##lname);			\
> +}									\
>  static __always_inline void __SetPage##uname(struct page *page)		\
>  {									\
>  	VM_BUG_ON_PAGE(!PageType(page, 0), page);			\
>  	page->page_type &= ~PG_##lname;					\
>  }									\
> +static __always_inline void __folio_set_##lname(struct folio *folio)	\
> +{									\
> +	VM_BUG_ON_FOLIO(!folio_test_type(folio, 0), folio);		\
> +	folio->page.page_type &= ~PG_##lname;				\
> +}									\
>  static __always_inline void __ClearPage##uname(struct page *page)	\
>  {									\
>  	VM_BUG_ON_PAGE(!Page##uname(page), page);			\
>  	page->page_type |= PG_##lname;					\
> -}
> +}									\
> +static __always_inline void __folio_clear_##lname(struct folio *folio)	\
> +{									\
> +	VM_BUG_ON_FOLIO(!folio_test_##lname(folio), folio);		\
> +	folio->page.page_type |= PG_##lname;				\
> +}									\
>  
>  /*
>   * PageBuddy() indicates that the page is free and in the buddy system
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 02/34] s390: Use _pt_s390_gaddr for gmap address tracking

[Vishal Moola (Oracle)]

s390 uses page->index to keep track of page tables for the guest address
space. In an attempt to consolidate the usage of page fields in s390,
replace _pt_pad_2 with _pt_s390_gaddr to replace page->index in gmap.

This will help with the splitting of struct ptdesc from struct page, as
well as allow s390 to use _pt_frag_refcount for fragmented page table
tracking.

Since page->_pt_s390_gaddr aliases with mapping, ensure its set to NULL
before freeing the pages as well.

This also reverts commit 7e25de77bc5ea ("s390/mm: use pmd_pgtable_page()
helper in __gmap_segment_gaddr()") which had s390 use
pmd_pgtable_page() to get a gmap page table, as pmd_pgtable_page()
should be used for more generic process page tables.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/s390/mm/gmap.c      | 56 +++++++++++++++++++++++++++-------------
 include/linux/mm_types.h |  2 +-
 2 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index dc90d1eb0d55..81c683426b49 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -70,7 +70,7 @@ static struct gmap *gmap_alloc(unsigned long limit)
 	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
 	if (!page)
 		goto out_free;
-	page->index = 0;
+	page->_pt_s390_gaddr = 0;
 	list_add(&page->lru, &gmap->crst_list);
 	table = page_to_virt(page);
 	crst_table_init(table, etype);
@@ -187,16 +187,20 @@ static void gmap_free(struct gmap *gmap)
 	if (!(gmap_is_shadow(gmap) && gmap->removed))
 		gmap_flush_tlb(gmap);
 	/* Free all segment & region tables. */
-	list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
+	list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
+		page->_pt_s390_gaddr = 0;
 		__free_pages(page, CRST_ALLOC_ORDER);
+	}
 	gmap_radix_tree_free(&gmap->guest_to_host);
 	gmap_radix_tree_free(&gmap->host_to_guest);
 
 	/* Free additional data for a shadow gmap */
 	if (gmap_is_shadow(gmap)) {
 		/* Free all page tables. */
-		list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
+		list_for_each_entry_safe(page, next, &gmap->pt_list, lru) {
+			page->_pt_s390_gaddr = 0;
 			page_table_free_pgste(page);
+		}
 		gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
 		/* Release reference to the parent */
 		gmap_put(gmap->parent);
@@ -318,12 +322,14 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
 		list_add(&page->lru, &gmap->crst_list);
 		*table = __pa(new) | _REGION_ENTRY_LENGTH |
 			(*table & _REGION_ENTRY_TYPE_MASK);
-		page->index = gaddr;
+		page->_pt_s390_gaddr = gaddr;
 		page = NULL;
 	}
 	spin_unlock(&gmap->guest_table_lock);
-	if (page)
+	if (page) {
+		page->_pt_s390_gaddr = 0;
 		__free_pages(page, CRST_ALLOC_ORDER);
+	}
 	return 0;
 }
 
@@ -336,12 +342,14 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
 static unsigned long __gmap_segment_gaddr(unsigned long *entry)
 {
 	struct page *page;
-	unsigned long offset;
+	unsigned long offset, mask;
 
 	offset = (unsigned long) entry / sizeof(unsigned long);
 	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
-	page = pmd_pgtable_page((pmd_t *) entry);
-	return page->index + offset;
+	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
+	page = virt_to_page((void *)((unsigned long) entry & mask));
+
+	return page->_pt_s390_gaddr + offset;
 }
 
 /**
@@ -1351,6 +1359,7 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
 	/* Free page table */
 	page = phys_to_page(pgt);
 	list_del(&page->lru);
+	page->_pt_s390_gaddr = 0;
 	page_table_free_pgste(page);
 }
 
@@ -1379,6 +1388,7 @@ static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
 		/* Free page table */
 		page = phys_to_page(pgt);
 		list_del(&page->lru);
+		page->_pt_s390_gaddr = 0;
 		page_table_free_pgste(page);
 	}
 }
@@ -1409,6 +1419,7 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
 	/* Free segment table */
 	page = phys_to_page(sgt);
 	list_del(&page->lru);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 }
 
@@ -1437,6 +1448,7 @@ static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
 		/* Free segment table */
 		page = phys_to_page(sgt);
 		list_del(&page->lru);
+		page->_pt_s390_gaddr = 0;
 		__free_pages(page, CRST_ALLOC_ORDER);
 	}
 }
@@ -1467,6 +1479,7 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
 	/* Free region 3 table */
 	page = phys_to_page(r3t);
 	list_del(&page->lru);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 }
 
@@ -1495,6 +1508,7 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
 		/* Free region 3 table */
 		page = phys_to_page(r3t);
 		list_del(&page->lru);
+		page->_pt_s390_gaddr = 0;
 		__free_pages(page, CRST_ALLOC_ORDER);
 	}
 }
@@ -1525,6 +1539,7 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
 	/* Free region 2 table */
 	page = phys_to_page(r2t);
 	list_del(&page->lru);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 }
 
@@ -1557,6 +1572,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
 		/* Free region 2 table */
 		page = phys_to_page(r2t);
 		list_del(&page->lru);
+		page->_pt_s390_gaddr = 0;
 		__free_pages(page, CRST_ALLOC_ORDER);
 	}
 }
@@ -1762,9 +1778,9 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
 	if (!page)
 		return -ENOMEM;
-	page->index = r2t & _REGION_ENTRY_ORIGIN;
+	page->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->index |= GMAP_SHADOW_FAKE_TABLE;
+		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
 	s_r2t = page_to_phys(page);
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
@@ -1814,6 +1830,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 	return rc;
 }
@@ -1846,9 +1863,9 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
 	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
 	if (!page)
 		return -ENOMEM;
-	page->index = r3t & _REGION_ENTRY_ORIGIN;
+	page->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->index |= GMAP_SHADOW_FAKE_TABLE;
+		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
 	s_r3t = page_to_phys(page);
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
@@ -1898,6 +1915,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 	return rc;
 }
@@ -1930,9 +1948,9 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
 	if (!page)
 		return -ENOMEM;
-	page->index = sgt & _REGION_ENTRY_ORIGIN;
+	page->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->index |= GMAP_SHADOW_FAKE_TABLE;
+		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
 	s_sgt = page_to_phys(page);
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
@@ -1982,6 +2000,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
+	page->_pt_s390_gaddr = 0;
 	__free_pages(page, CRST_ALLOC_ORDER);
 	return rc;
 }
@@ -2014,9 +2033,9 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
 	if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
 		/* Shadow page tables are full pages (pte+pgste) */
 		page = pfn_to_page(*table >> PAGE_SHIFT);
-		*pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
+		*pgt = page->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
 		*dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
-		*fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
+		*fake = !!(page->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
 		rc = 0;
 	} else  {
 		rc = -EAGAIN;
@@ -2054,9 +2073,9 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 	page = page_table_alloc_pgste(sg->mm);
 	if (!page)
 		return -ENOMEM;
-	page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
+	page->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
 	if (fake)
-		page->index |= GMAP_SHADOW_FAKE_TABLE;
+		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
 	s_pgt = page_to_phys(page);
 	/* Install shadow page table */
 	spin_lock(&sg->guest_table_lock);
@@ -2101,6 +2120,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
+	page->_pt_s390_gaddr = 0;
 	page_table_free_pgste(page);
 	return rc;
 
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 306a3d1a0fa6..6161fe1ae5b8 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -144,7 +144,7 @@ struct page {
 		struct {	/* Page table pages */
 			unsigned long _pt_pad_1;	/* compound_head */
 			pgtable_t pmd_huge_pte; /* protected by page->ptl */
-			unsigned long _pt_pad_2;	/* mapping */
+			unsigned long _pt_s390_gaddr;	/* mapping */
 			union {
 				struct mm_struct *pt_mm; /* x86 pgds only */
 				atomic_t pt_frag_refcount; /* powerpc */
-- 
2.40.1

Re: [PATCH v4 02/34] s390: Use _pt_s390_gaddr for gmap address tracking

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:51PM -0700, Vishal Moola (Oracle) wrote:
> s390 uses page->index to keep track of page tables for the guest address
> space. In an attempt to consolidate the usage of page fields in s390,
> replace _pt_pad_2 with _pt_s390_gaddr to replace page->index in gmap.
> 
> This will help with the splitting of struct ptdesc from struct page, as
> well as allow s390 to use _pt_frag_refcount for fragmented page table
> tracking.
> 
> Since page->_pt_s390_gaddr aliases with mapping, ensure its set to NULL
> before freeing the pages as well.

I'm looking at the final result and unless I've missed something, setting
of _pt_s390_gaddr to 0 is always followed by pagetable_free().
Can't we have pagetable_free() take care of zeroing _pt_s390_gaddr?
I think patch 16 ("s390: Convert various gmap functions to use ptdescs")
would be the right place for that.

Otherwise:

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
 
> This also reverts commit 7e25de77bc5ea ("s390/mm: use pmd_pgtable_page()
> helper in __gmap_segment_gaddr()") which had s390 use
> pmd_pgtable_page() to get a gmap page table, as pmd_pgtable_page()
> should be used for more generic process page tables.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>  arch/s390/mm/gmap.c      | 56 +++++++++++++++++++++++++++-------------
>  include/linux/mm_types.h |  2 +-
>  2 files changed, 39 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index dc90d1eb0d55..81c683426b49 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -70,7 +70,7 @@ static struct gmap *gmap_alloc(unsigned long limit)
>  	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
>  	if (!page)
>  		goto out_free;
> -	page->index = 0;
> +	page->_pt_s390_gaddr = 0;
>  	list_add(&page->lru, &gmap->crst_list);
>  	table = page_to_virt(page);
>  	crst_table_init(table, etype);
> @@ -187,16 +187,20 @@ static void gmap_free(struct gmap *gmap)
>  	if (!(gmap_is_shadow(gmap) && gmap->removed))
>  		gmap_flush_tlb(gmap);
>  	/* Free all segment & region tables. */
> -	list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
> +	list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
> +		page->_pt_s390_gaddr = 0;
>  		__free_pages(page, CRST_ALLOC_ORDER);
> +	}
>  	gmap_radix_tree_free(&gmap->guest_to_host);
>  	gmap_radix_tree_free(&gmap->host_to_guest);
>  
>  	/* Free additional data for a shadow gmap */
>  	if (gmap_is_shadow(gmap)) {
>  		/* Free all page tables. */
> -		list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
> +		list_for_each_entry_safe(page, next, &gmap->pt_list, lru) {
> +			page->_pt_s390_gaddr = 0;
>  			page_table_free_pgste(page);
> +		}
>  		gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
>  		/* Release reference to the parent */
>  		gmap_put(gmap->parent);
> @@ -318,12 +322,14 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>  		list_add(&page->lru, &gmap->crst_list);
>  		*table = __pa(new) | _REGION_ENTRY_LENGTH |
>  			(*table & _REGION_ENTRY_TYPE_MASK);
> -		page->index = gaddr;
> +		page->_pt_s390_gaddr = gaddr;
>  		page = NULL;
>  	}
>  	spin_unlock(&gmap->guest_table_lock);
> -	if (page)
> +	if (page) {
> +		page->_pt_s390_gaddr = 0;
>  		__free_pages(page, CRST_ALLOC_ORDER);
> +	}
>  	return 0;
>  }
>  
> @@ -336,12 +342,14 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>  static unsigned long __gmap_segment_gaddr(unsigned long *entry)
>  {
>  	struct page *page;
> -	unsigned long offset;
> +	unsigned long offset, mask;
>  
>  	offset = (unsigned long) entry / sizeof(unsigned long);
>  	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
> -	page = pmd_pgtable_page((pmd_t *) entry);
> -	return page->index + offset;
> +	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> +	page = virt_to_page((void *)((unsigned long) entry & mask));
> +
> +	return page->_pt_s390_gaddr + offset;
>  }
>  
>  /**
> @@ -1351,6 +1359,7 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
>  	/* Free page table */
>  	page = phys_to_page(pgt);
>  	list_del(&page->lru);
> +	page->_pt_s390_gaddr = 0;
>  	page_table_free_pgste(page);
>  }
>  
> @@ -1379,6 +1388,7 @@ static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
>  		/* Free page table */
>  		page = phys_to_page(pgt);
>  		list_del(&page->lru);
> +		page->_pt_s390_gaddr = 0;
>  		page_table_free_pgste(page);
>  	}
>  }
> @@ -1409,6 +1419,7 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
>  	/* Free segment table */
>  	page = phys_to_page(sgt);
>  	list_del(&page->lru);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  }
>  
> @@ -1437,6 +1448,7 @@ static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
>  		/* Free segment table */
>  		page = phys_to_page(sgt);
>  		list_del(&page->lru);
> +		page->_pt_s390_gaddr = 0;
>  		__free_pages(page, CRST_ALLOC_ORDER);
>  	}
>  }
> @@ -1467,6 +1479,7 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
>  	/* Free region 3 table */
>  	page = phys_to_page(r3t);
>  	list_del(&page->lru);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  }
>  
> @@ -1495,6 +1508,7 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
>  		/* Free region 3 table */
>  		page = phys_to_page(r3t);
>  		list_del(&page->lru);
> +		page->_pt_s390_gaddr = 0;
>  		__free_pages(page, CRST_ALLOC_ORDER);
>  	}
>  }
> @@ -1525,6 +1539,7 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
>  	/* Free region 2 table */
>  	page = phys_to_page(r2t);
>  	list_del(&page->lru);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  }
>  
> @@ -1557,6 +1572,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
>  		/* Free region 2 table */
>  		page = phys_to_page(r2t);
>  		list_del(&page->lru);
> +		page->_pt_s390_gaddr = 0;
>  		__free_pages(page, CRST_ALLOC_ORDER);
>  	}
>  }
> @@ -1762,9 +1778,9 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
>  	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
>  	if (!page)
>  		return -ENOMEM;
> -	page->index = r2t & _REGION_ENTRY_ORIGIN;
> +	page->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->index |= GMAP_SHADOW_FAKE_TABLE;
> +		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
>  	s_r2t = page_to_phys(page);
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
> @@ -1814,6 +1830,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  	return rc;
>  }
> @@ -1846,9 +1863,9 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
>  	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
>  	if (!page)
>  		return -ENOMEM;
> -	page->index = r3t & _REGION_ENTRY_ORIGIN;
> +	page->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->index |= GMAP_SHADOW_FAKE_TABLE;
> +		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
>  	s_r3t = page_to_phys(page);
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
> @@ -1898,6 +1915,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  	return rc;
>  }
> @@ -1930,9 +1948,9 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
>  	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
>  	if (!page)
>  		return -ENOMEM;
> -	page->index = sgt & _REGION_ENTRY_ORIGIN;
> +	page->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->index |= GMAP_SHADOW_FAKE_TABLE;
> +		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
>  	s_sgt = page_to_phys(page);
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
> @@ -1982,6 +2000,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> +	page->_pt_s390_gaddr = 0;
>  	__free_pages(page, CRST_ALLOC_ORDER);
>  	return rc;
>  }
> @@ -2014,9 +2033,9 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
>  	if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
>  		/* Shadow page tables are full pages (pte+pgste) */
>  		page = pfn_to_page(*table >> PAGE_SHIFT);
> -		*pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
> +		*pgt = page->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
>  		*dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
> -		*fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
> +		*fake = !!(page->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
>  		rc = 0;
>  	} else  {
>  		rc = -EAGAIN;
> @@ -2054,9 +2073,9 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
>  	page = page_table_alloc_pgste(sg->mm);
>  	if (!page)
>  		return -ENOMEM;
> -	page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
> +	page->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
>  	if (fake)
> -		page->index |= GMAP_SHADOW_FAKE_TABLE;
> +		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
>  	s_pgt = page_to_phys(page);
>  	/* Install shadow page table */
>  	spin_lock(&sg->guest_table_lock);
> @@ -2101,6 +2120,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> +	page->_pt_s390_gaddr = 0;
>  	page_table_free_pgste(page);
>  	return rc;
>  
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 306a3d1a0fa6..6161fe1ae5b8 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -144,7 +144,7 @@ struct page {
>  		struct {	/* Page table pages */
>  			unsigned long _pt_pad_1;	/* compound_head */
>  			pgtable_t pmd_huge_pte; /* protected by page->ptl */
> -			unsigned long _pt_pad_2;	/* mapping */
> +			unsigned long _pt_s390_gaddr;	/* mapping */
>  			union {
>  				struct mm_struct *pt_mm; /* x86 pgds only */
>  				atomic_t pt_frag_refcount; /* powerpc */
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 03/34] s390: Use pt_frag_refcount for pagetables

[Vishal Moola (Oracle)]

s390 currently uses _refcount to identify fragmented page tables.
The page table struct already has a member pt_frag_refcount used by
powerpc, so have s390 use that instead of the _refcount field as well.
This improves the safety for _refcount and the page table tracking.

This also allows us to simplify the tracking since we can once again use
the lower byte of pt_frag_refcount instead of the upper byte of _refcount.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/s390/mm/pgalloc.c | 38 +++++++++++++++-----------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 66ab68db9842..6b99932abc66 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -182,20 +182,17 @@ void page_table_free_pgste(struct page *page)
  * As follows from the above, no unallocated or fully allocated parent
  * pages are contained in mm_context_t::pgtable_list.
  *
- * The upper byte (bits 24-31) of the parent page _refcount is used
+ * The lower byte (bits 0-7) of the parent page pt_frag_refcount is used
  * for tracking contained 2KB-pgtables and has the following format:
  *
  *   PP  AA
- * 01234567    upper byte (bits 24-31) of struct page::_refcount
+ * 01234567    upper byte (bits 0-7) of struct page::pt_frag_refcount
  *   ||  ||
  *   ||  |+--- upper 2KB-pgtable is allocated
  *   ||  +---- lower 2KB-pgtable is allocated
  *   |+------- upper 2KB-pgtable is pending for removal
  *   +-------- lower 2KB-pgtable is pending for removal
  *
- * (See commit 620b4e903179 ("s390: use _refcount for pgtables") on why
- * using _refcount is possible).
- *
  * When 2KB-pgtable is allocated the corresponding AA bit is set to 1.
  * The parent page is either:
  *   - added to mm_context_t::pgtable_list in case the second half of the
@@ -243,11 +240,12 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 		if (!list_empty(&mm->context.pgtable_list)) {
 			page = list_first_entry(&mm->context.pgtable_list,
 						struct page, lru);
-			mask = atomic_read(&page->_refcount) >> 24;
+			mask = atomic_read(&page->pt_frag_refcount);
 			/*
 			 * The pending removal bits must also be checked.
 			 * Failure to do so might lead to an impossible
-			 * value of (i.e 0x13 or 0x23) written to _refcount.
+			 * value of (i.e 0x13 or 0x23) written to
+			 * pt_frag_refcount.
 			 * Such values violate the assumption that pending and
 			 * allocation bits are mutually exclusive, and the rest
 			 * of the code unrails as result. That could lead to
@@ -259,8 +257,8 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 				bit = mask & 1;		/* =1 -> second 2K */
 				if (bit)
 					table += PTRS_PER_PTE;
-				atomic_xor_bits(&page->_refcount,
-							0x01U << (bit + 24));
+				atomic_xor_bits(&page->pt_frag_refcount,
+							0x01U << bit);
 				list_del(&page->lru);
 			}
 		}
@@ -281,12 +279,12 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 	table = (unsigned long *) page_to_virt(page);
 	if (mm_alloc_pgste(mm)) {
 		/* Return 4K page table with PGSTEs */
-		atomic_xor_bits(&page->_refcount, 0x03U << 24);
+		atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
 		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	} else {
 		/* Return the first 2K fragment of the page */
-		atomic_xor_bits(&page->_refcount, 0x01U << 24);
+		atomic_xor_bits(&page->pt_frag_refcount, 0x01U);
 		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
 		spin_lock_bh(&mm->context.lock);
 		list_add(&page->lru, &mm->context.pgtable_list);
@@ -323,22 +321,19 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
 		 * will happen outside of the critical section from this
 		 * function or from __tlb_remove_table()
 		 */
-		mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
-		mask >>= 24;
+		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
 		if (mask & 0x03U)
 			list_add(&page->lru, &mm->context.pgtable_list);
 		else
 			list_del(&page->lru);
 		spin_unlock_bh(&mm->context.lock);
-		mask = atomic_xor_bits(&page->_refcount, 0x10U << (bit + 24));
-		mask >>= 24;
+		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x10U << bit);
 		if (mask != 0x00U)
 			return;
 		half = 0x01U << bit;
 	} else {
 		half = 0x03U;
-		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
-		mask >>= 24;
+		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
 	}
 
 	page_table_release_check(page, table, half, mask);
@@ -368,8 +363,7 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 	 * outside of the critical section from __tlb_remove_table() or from
 	 * page_table_free()
 	 */
-	mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
-	mask >>= 24;
+	mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
 	if (mask & 0x03U)
 		list_add_tail(&page->lru, &mm->context.pgtable_list);
 	else
@@ -391,14 +385,12 @@ void __tlb_remove_table(void *_table)
 		return;
 	case 0x01U:	/* lower 2K of a 4K page table */
 	case 0x02U:	/* higher 2K of a 4K page table */
-		mask = atomic_xor_bits(&page->_refcount, mask << (4 + 24));
-		mask >>= 24;
+		mask = atomic_xor_bits(&page->pt_frag_refcount, mask << 4);
 		if (mask != 0x00U)
 			return;
 		break;
 	case 0x03U:	/* 4K page table with pgstes */
-		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
-		mask >>= 24;
+		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
 		break;
 	}
 
-- 
2.40.1

Re: [PATCH v4 03/34] s390: Use pt_frag_refcount for pagetables

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:52PM -0700, Vishal Moola (Oracle) wrote:
> s390 currently uses _refcount to identify fragmented page tables.
> The page table struct already has a member pt_frag_refcount used by
> powerpc, so have s390 use that instead of the _refcount field as well.
> This improves the safety for _refcount and the page table tracking.
> 
> This also allows us to simplify the tracking since we can once again use
> the lower byte of pt_frag_refcount instead of the upper byte of _refcount.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

One nit below, otherwise

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/s390/mm/pgalloc.c | 38 +++++++++++++++-----------------------
>  1 file changed, 15 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
> index 66ab68db9842..6b99932abc66 100644
> --- a/arch/s390/mm/pgalloc.c
> +++ b/arch/s390/mm/pgalloc.c
> @@ -182,20 +182,17 @@ void page_table_free_pgste(struct page *page)
>   * As follows from the above, no unallocated or fully allocated parent
>   * pages are contained in mm_context_t::pgtable_list.
>   *
> - * The upper byte (bits 24-31) of the parent page _refcount is used
> + * The lower byte (bits 0-7) of the parent page pt_frag_refcount is used
>   * for tracking contained 2KB-pgtables and has the following format:
>   *
>   *   PP  AA
> - * 01234567    upper byte (bits 24-31) of struct page::_refcount
> + * 01234567    upper byte (bits 0-7) of struct page::pt_frag_refcount

Nit:              lower

>   *   ||  ||
>   *   ||  |+--- upper 2KB-pgtable is allocated
>   *   ||  +---- lower 2KB-pgtable is allocated
>   *   |+------- upper 2KB-pgtable is pending for removal
>   *   +-------- lower 2KB-pgtable is pending for removal
>   *
> - * (See commit 620b4e903179 ("s390: use _refcount for pgtables") on why
> - * using _refcount is possible).
> - *
>   * When 2KB-pgtable is allocated the corresponding AA bit is set to 1.
>   * The parent page is either:
>   *   - added to mm_context_t::pgtable_list in case the second half of the
> @@ -243,11 +240,12 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  		if (!list_empty(&mm->context.pgtable_list)) {
>  			page = list_first_entry(&mm->context.pgtable_list,
>  						struct page, lru);
> -			mask = atomic_read(&page->_refcount) >> 24;
> +			mask = atomic_read(&page->pt_frag_refcount);
>  			/*
>  			 * The pending removal bits must also be checked.
>  			 * Failure to do so might lead to an impossible
> -			 * value of (i.e 0x13 or 0x23) written to _refcount.
> +			 * value of (i.e 0x13 or 0x23) written to
> +			 * pt_frag_refcount.
>  			 * Such values violate the assumption that pending and
>  			 * allocation bits are mutually exclusive, and the rest
>  			 * of the code unrails as result. That could lead to
> @@ -259,8 +257,8 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  				bit = mask & 1;		/* =1 -> second 2K */
>  				if (bit)
>  					table += PTRS_PER_PTE;
> -				atomic_xor_bits(&page->_refcount,
> -							0x01U << (bit + 24));
> +				atomic_xor_bits(&page->pt_frag_refcount,
> +							0x01U << bit);
>  				list_del(&page->lru);
>  			}
>  		}
> @@ -281,12 +279,12 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  	table = (unsigned long *) page_to_virt(page);
>  	if (mm_alloc_pgste(mm)) {
>  		/* Return 4K page table with PGSTEs */
> -		atomic_xor_bits(&page->_refcount, 0x03U << 24);
> +		atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
>  		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
>  		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
>  	} else {
>  		/* Return the first 2K fragment of the page */
> -		atomic_xor_bits(&page->_refcount, 0x01U << 24);
> +		atomic_xor_bits(&page->pt_frag_refcount, 0x01U);
>  		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
>  		spin_lock_bh(&mm->context.lock);
>  		list_add(&page->lru, &mm->context.pgtable_list);
> @@ -323,22 +321,19 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
>  		 * will happen outside of the critical section from this
>  		 * function or from __tlb_remove_table()
>  		 */
> -		mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
> -		mask >>= 24;
> +		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
>  		if (mask & 0x03U)
>  			list_add(&page->lru, &mm->context.pgtable_list);
>  		else
>  			list_del(&page->lru);
>  		spin_unlock_bh(&mm->context.lock);
> -		mask = atomic_xor_bits(&page->_refcount, 0x10U << (bit + 24));
> -		mask >>= 24;
> +		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x10U << bit);
>  		if (mask != 0x00U)
>  			return;
>  		half = 0x01U << bit;
>  	} else {
>  		half = 0x03U;
> -		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
> -		mask >>= 24;
> +		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
>  	}
>  
>  	page_table_release_check(page, table, half, mask);
> @@ -368,8 +363,7 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
>  	 * outside of the critical section from __tlb_remove_table() or from
>  	 * page_table_free()
>  	 */
> -	mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
> -	mask >>= 24;
> +	mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
>  	if (mask & 0x03U)
>  		list_add_tail(&page->lru, &mm->context.pgtable_list);
>  	else
> @@ -391,14 +385,12 @@ void __tlb_remove_table(void *_table)
>  		return;
>  	case 0x01U:	/* lower 2K of a 4K page table */
>  	case 0x02U:	/* higher 2K of a 4K page table */
> -		mask = atomic_xor_bits(&page->_refcount, mask << (4 + 24));
> -		mask >>= 24;
> +		mask = atomic_xor_bits(&page->pt_frag_refcount, mask << 4);
>  		if (mask != 0x00U)
>  			return;
>  		break;
>  	case 0x03U:	/* 4K page table with pgstes */
> -		mask = atomic_xor_bits(&page->_refcount, 0x03U << 24);
> -		mask >>= 24;
> +		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
>  		break;
>  	}
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 04/34] pgtable: Create struct ptdesc

[Vishal Moola (Oracle)]

Currently, page table information is stored within struct page. As part
of simplifying struct page, create struct ptdesc for page table
information.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index c5a51481bbb9..330de96ebfd6 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
 #endif /* CONFIG_MMU */
 
+
+/**
+ * struct ptdesc - Memory descriptor for page tables.
+ * @__page_flags: Same as page flags. Unused for page tables.
+ * @pt_list: List of used page tables. Used for s390 and x86.
+ * @_pt_pad_1: Padding that aliases with page's compound head.
+ * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
+ * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
+ * @pt_mm: Used for x86 pgds.
+ * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
+ * @ptl: Lock for the page table.
+ *
+ * This struct overlays struct page for now. Do not modify without a good
+ * understanding of the issues.
+ */
+struct ptdesc {
+	unsigned long __page_flags;
+
+	union {
+		struct list_head pt_list;
+		struct {
+			unsigned long _pt_pad_1;
+			pgtable_t pmd_huge_pte;
+		};
+	};
+	unsigned long _pt_s390_gaddr;
+
+	union {
+		struct mm_struct *pt_mm;
+		atomic_t pt_frag_refcount;
+	};
+
+#if ALLOC_SPLIT_PTLOCKS
+	spinlock_t *ptl;
+#else
+	spinlock_t ptl;
+#endif
+};
+
+#define TABLE_MATCH(pg, pt)						\
+	static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
+TABLE_MATCH(flags, __page_flags);
+TABLE_MATCH(compound_head, pt_list);
+TABLE_MATCH(compound_head, _pt_pad_1);
+TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
+TABLE_MATCH(mapping, _pt_s390_gaddr);
+TABLE_MATCH(pt_mm, pt_mm);
+TABLE_MATCH(ptl, ptl);
+#undef TABLE_MATCH
+static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
+
 /*
  * No-op macros that just return the current protection value. Defined here
  * because these macros can be used even if CONFIG_MMU is not defined.
-- 
2.40.1

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:53PM -0700, Vishal Moola (Oracle) wrote:
> Currently, page table information is stored within struct page. As part
> of simplifying struct page, create struct ptdesc for page table
> information.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
> 
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index c5a51481bbb9..330de96ebfd6 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
>  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
>  #endif /* CONFIG_MMU */
>  
> +
> +/**
> + * struct ptdesc - Memory descriptor for page tables.
> + * @__page_flags: Same as page flags. Unused for page tables.
> + * @pt_list: List of used page tables. Used for s390 and x86.
> + * @_pt_pad_1: Padding that aliases with page's compound head.
> + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> + * @pt_mm: Used for x86 pgds.
> + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> + * @ptl: Lock for the page table.

Do you mind aligning the descriptions by @pt_frag_refcount? I think it'll
be more readable.

> + *
> + * This struct overlays struct page for now. Do not modify without a good
> + * understanding of the issues.
> + */
> +struct ptdesc {
> +	unsigned long __page_flags;
> +
> +	union {
> +		struct list_head pt_list;
> +		struct {
> +			unsigned long _pt_pad_1;
> +			pgtable_t pmd_huge_pte;
> +		};
> +	};
> +	unsigned long _pt_s390_gaddr;
> +
> +	union {
> +		struct mm_struct *pt_mm;
> +		atomic_t pt_frag_refcount;
> +	};
> +
> +#if ALLOC_SPLIT_PTLOCKS
> +	spinlock_t *ptl;
> +#else
> +	spinlock_t ptl;
> +#endif
> +};
> +
> +#define TABLE_MATCH(pg, pt)						\
> +	static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
> +TABLE_MATCH(flags, __page_flags);
> +TABLE_MATCH(compound_head, pt_list);
> +TABLE_MATCH(compound_head, _pt_pad_1);
> +TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
> +TABLE_MATCH(mapping, _pt_s390_gaddr);
> +TABLE_MATCH(pt_mm, pt_mm);
> +TABLE_MATCH(ptl, ptl);
> +#undef TABLE_MATCH
> +static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
> +
>  /*
>   * No-op macros that just return the current protection value. Defined here
>   * because these macros can be used even if CONFIG_MMU is not defined.
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Hugh Dickins]

On Mon, 12 Jun 2023, Vishal Moola (Oracle) wrote:

> Currently, page table information is stored within struct page. As part
> of simplifying struct page, create struct ptdesc for page table
> information.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Vishal, as I think you have already guessed, your ptdesc series and
my pte_free_defer() "mm: free retracted page table by RCU" series are
on a collision course.

Probably just trivial collisions in most architectures, which either
of us can easily adjust to the other; powerpc likely to be more awkward,
but fairly easily resolved; s390 quite a problem.

I've so far been unable to post a v2 of my series (and powerpc and s390
were stupidly wrong in the v1), because a good s390 patch is not yet
decided - Gerald Schaefer and I are currently working on that, on the
s390 list (I took off most Ccs until we are settled and I can post v2).

As you have no doubt found yourself, s390 has sophisticated handling of
free half-pages already, and I need to add rcu_head usage in there too:
it's tricky to squeeze it all in, and ptdesc does not appear to help us
in any way (though mostly it's just changing some field names, okay).

If ptdesc were actually allowing a flexible structure which architectures
could add into, that would (in some future) be nice; but of course at
present it's still fitting it all into one struct page, and mandating
new restrictions which just make an architecture's job harder.

Some notes on problematic fields below FYI.

> ---
>  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
> 
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index c5a51481bbb9..330de96ebfd6 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
>  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
>  #endif /* CONFIG_MMU */
>  
> +
> +/**
> + * struct ptdesc - Memory descriptor for page tables.
> + * @__page_flags: Same as page flags. Unused for page tables.
> + * @pt_list: List of used page tables. Used for s390 and x86.
> + * @_pt_pad_1: Padding that aliases with page's compound head.
> + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> + * @pt_mm: Used for x86 pgds.
> + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> + * @ptl: Lock for the page table.
> + *
> + * This struct overlays struct page for now. Do not modify without a good
> + * understanding of the issues.
> + */
> +struct ptdesc {
> +	unsigned long __page_flags;
> +
> +	union {
> +		struct list_head pt_list;

I shall be needing struct rcu_head rcu_head (or pt_rcu_head or whatever,
if you prefer) in this union too.  Sharing the lru or pt_list with rcu_head
is what's difficult to get right and efficient on s390 - and if ptdesc gave
us an independent rcu_head for each page table, that would be a blessing!
but sadly not, it still has to squeeze into a struct page.

> +		struct {
> +			unsigned long _pt_pad_1;
> +			pgtable_t pmd_huge_pte;
> +		};
> +	};
> +	unsigned long _pt_s390_gaddr;
> +
> +	union {
> +		struct mm_struct *pt_mm;
> +		atomic_t pt_frag_refcount;

Whether s390 will want pt_mm is not yet decided: I want to use it,
Gerald prefers to go without it; but if we do end up using it,
then pt_frag_refcount is a luxury we would have to give up.

s390 does very well already with its _refcount tricks, and I'd expect
powerpc's simpler but more wasteful implementation to work as well
with _refcount too - I know that a few years back, powerpc did misuse
_refcount (it did not allow for speculative accesses, thought it had
sole ownership of that field); but s390 copes well with that, and I
expect powerpc can do so too, without the luxury of pt_frag_refcount.

But I've no desire to undo powerpc's use of pt_frag_refcount:
just warning that we may want to undo any use of it in s390.

I thought I had more issues to mention, probably Gerald will
remind me of a whole new unexplored dimension! gmap perhaps.

Hugh

> +	};
> +
> +#if ALLOC_SPLIT_PTLOCKS
> +	spinlock_t *ptl;
> +#else
> +	spinlock_t ptl;
> +#endif
> +};
> +
> +#define TABLE_MATCH(pg, pt)						\
> +	static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
> +TABLE_MATCH(flags, __page_flags);
> +TABLE_MATCH(compound_head, pt_list);
> +TABLE_MATCH(compound_head, _pt_pad_1);
> +TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
> +TABLE_MATCH(mapping, _pt_s390_gaddr);
> +TABLE_MATCH(pt_mm, pt_mm);
> +TABLE_MATCH(ptl, ptl);
> +#undef TABLE_MATCH
> +static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
> +
>  /*
>   * No-op macros that just return the current protection value. Defined here
>   * because these macros can be used even if CONFIG_MMU is not defined.
> -- 
> 2.40.1

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Matthew Wilcox]

On Thu, Jun 15, 2023 at 12:57:19AM -0700, Hugh Dickins wrote:
> Probably just trivial collisions in most architectures, which either
> of us can easily adjust to the other; powerpc likely to be more awkward,
> but fairly easily resolved; s390 quite a problem.
> 
> I've so far been unable to post a v2 of my series (and powerpc and s390
> were stupidly wrong in the v1), because a good s390 patch is not yet
> decided - Gerald Schaefer and I are currently working on that, on the
> s390 list (I took off most Ccs until we are settled and I can post v2).
> 
> As you have no doubt found yourself, s390 has sophisticated handling of
> free half-pages already, and I need to add rcu_head usage in there too:
> it's tricky to squeeze it all in, and ptdesc does not appear to help us
> in any way (though mostly it's just changing some field names, okay).
> 
> If ptdesc were actually allowing a flexible structure which architectures
> could add into, that would (in some future) be nice; but of course at
> present it's still fitting it all into one struct page, and mandating
> new restrictions which just make an architecture's job harder.

The intent is to get ptdescs to be dynamically allocated at some point
in the ~2-3 years out future when we have finished the folio project ...
which is not a terribly helpful thing for me to say.

I have three suggestions, probably all dreadful:

1. s390 could change its behaviour to always allocate page tables in
pairs.  That is, it fills in two pmd_t entries any time it takes a fault
in either of them.

2. We could allocate two or four pages at a time for s390 to allocate
2kB pages from.  That gives us a lot more space to store RCU heads.

3. We could use s390 as a guinea-pig for dynamic ptdesc allocation.
Every time we allocate a struct page, we have a slab cache for an
s390-special definition of struct ptdesc, we allocate a ptdesc and store
a pointer to that in compound_head.

We could sweeten #3 by doing that not just for s390 but also for every
configuration which has ALLOC_SPLIT_PTLOCKS today.  That would get rid
of the ambiguity between "is ptl a pointer or a lock".

> But I've no desire to undo powerpc's use of pt_frag_refcount:
> just warning that we may want to undo any use of it in s390.

I would dearly love ppc & s390 to use the _same_ scheme to solve the
same problem.

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Vishal Moola]

On Thu, Jun 15, 2023 at 12:57 AM Hugh Dickins <hughd@google.com> wrote:
>
> On Mon, 12 Jun 2023, Vishal Moola (Oracle) wrote:
>
> > Currently, page table information is stored within struct page. As part
> > of simplifying struct page, create struct ptdesc for page table
> > information.
> >
> > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
>
> Vishal, as I think you have already guessed, your ptdesc series and
> my pte_free_defer() "mm: free retracted page table by RCU" series are
> on a collision course.
>
> Probably just trivial collisions in most architectures, which either
> of us can easily adjust to the other; powerpc likely to be more awkward,
> but fairly easily resolved; s390 quite a problem.
>
> I've so far been unable to post a v2 of my series (and powerpc and s390
> were stupidly wrong in the v1), because a good s390 patch is not yet
> decided - Gerald Schaefer and I are currently working on that, on the
> s390 list (I took off most Ccs until we are settled and I can post v2).
>
> As you have no doubt found yourself, s390 has sophisticated handling of
> free half-pages already, and I need to add rcu_head usage in there too:
> it's tricky to squeeze it all in, and ptdesc does not appear to help us
> in any way (though mostly it's just changing some field names, okay).
>
> If ptdesc were actually allowing a flexible structure which architectures
> could add into, that would (in some future) be nice; but of course at
> present it's still fitting it all into one struct page, and mandating
> new restrictions which just make an architecture's job harder.

A goal of ptdescs is to make architecture's jobs simpler and standardized.
Unfortunately, ptdescs are nowhere near isolated from struct page yet.
This version of struct ptdesc contains the exact number of fields architectures
need right now, just reorganized to be located next to each other. It *probably*
shouldn't make an architectures job harder, aside from discouraging their use
of yet even more members of struct page.

> Some notes on problematic fields below FYI.
>
> > ---
> >  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 51 insertions(+)
> >
> > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> > index c5a51481bbb9..330de96ebfd6 100644
> > --- a/include/linux/pgtable.h
> > +++ b/include/linux/pgtable.h
> > @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
> >  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
> >  #endif /* CONFIG_MMU */
> >
> > +
> > +/**
> > + * struct ptdesc - Memory descriptor for page tables.
> > + * @__page_flags: Same as page flags. Unused for page tables.
> > + * @pt_list: List of used page tables. Used for s390 and x86.
> > + * @_pt_pad_1: Padding that aliases with page's compound head.
> > + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> > + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> > + * @pt_mm: Used for x86 pgds.
> > + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> > + * @ptl: Lock for the page table.
> > + *
> > + * This struct overlays struct page for now. Do not modify without a good
> > + * understanding of the issues.
> > + */
> > +struct ptdesc {
> > +     unsigned long __page_flags;
> > +
> > +     union {
> > +             struct list_head pt_list;
>
> I shall be needing struct rcu_head rcu_head (or pt_rcu_head or whatever,
> if you prefer) in this union too.  Sharing the lru or pt_list with rcu_head
> is what's difficult to get right and efficient on s390 - and if ptdesc gave
> us an independent rcu_head for each page table, that would be a blessing!
> but sadly not, it still has to squeeze into a struct page.

I can add a pt_rcu_head along with a comment to deter aliasing issues :)
Independent rcu_heads aren't coming any time soon though :(

> > +             struct {
> > +                     unsigned long _pt_pad_1;
> > +                     pgtable_t pmd_huge_pte;
> > +             };
> > +     };
> > +     unsigned long _pt_s390_gaddr;
> > +
> > +     union {
> > +             struct mm_struct *pt_mm;
> > +             atomic_t pt_frag_refcount;
>
> Whether s390 will want pt_mm is not yet decided: I want to use it,
> Gerald prefers to go without it; but if we do end up using it,
> then pt_frag_refcount is a luxury we would have to give up.

I don't like the use of pt_mm for s390 either. s390 uses space equivalent
to all five words allocated in the page table struct (albeit in various places
of struct page). Using extra space (especially allocated for unrelated
reasons) just because it exists makes things more complicated and
confusing, and s390 is already confusing enough as a result of that.

If having access to pt_mm is necessary I can drop the
pt_frag_refcount patch, but I'd rather avoid it.

> s390 does very well already with its _refcount tricks, and I'd expect
> powerpc's simpler but more wasteful implementation to work as well
> with _refcount too - I know that a few years back, powerpc did misuse
> _refcount (it did not allow for speculative accesses, thought it had
> sole ownership of that field); but s390 copes well with that, and I
> expect powerpc can do so too, without the luxury of pt_frag_refcount.
>
> But I've no desire to undo powerpc's use of pt_frag_refcount:
> just warning that we may want to undo any use of it in s390.
>
> I thought I had more issues to mention, probably Gerald will
> remind me of a whole new unexplored dimension! gmap perhaps.
>
> Hugh
>
> > +     };
> > +
> > +#if ALLOC_SPLIT_PTLOCKS
> > +     spinlock_t *ptl;
> > +#else
> > +     spinlock_t ptl;
> > +#endif
> > +};
> > +
> > +#define TABLE_MATCH(pg, pt)                                          \
> > +     static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
> > +TABLE_MATCH(flags, __page_flags);
> > +TABLE_MATCH(compound_head, pt_list);
> > +TABLE_MATCH(compound_head, _pt_pad_1);
> > +TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
> > +TABLE_MATCH(mapping, _pt_s390_gaddr);
> > +TABLE_MATCH(pt_mm, pt_mm);
> > +TABLE_MATCH(ptl, ptl);
> > +#undef TABLE_MATCH
> > +static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
> > +
> >  /*
> >   * No-op macros that just return the current protection value. Defined here
> >   * because these macros can be used even if CONFIG_MMU is not defined.
> > --
> > 2.40.1

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Jason Gunthorpe]

On Mon, Jun 12, 2023 at 02:03:53PM -0700, Vishal Moola (Oracle) wrote:
> Currently, page table information is stored within struct page. As part
> of simplifying struct page, create struct ptdesc for page table
> information.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
> 
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index c5a51481bbb9..330de96ebfd6 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
>  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
>  #endif /* CONFIG_MMU */
>  
> +
> +/**
> + * struct ptdesc - Memory descriptor for page tables.
> + * @__page_flags: Same as page flags. Unused for page tables.
> + * @pt_list: List of used page tables. Used for s390 and x86.
> + * @_pt_pad_1: Padding that aliases with page's compound head.
> + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> + * @pt_mm: Used for x86 pgds.
> + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> + * @ptl: Lock for the page table.
> + *
> + * This struct overlays struct page for now. Do not modify without a good
> + * understanding of the issues.
> + */
> +struct ptdesc {
> +	unsigned long __page_flags;
> +
> +	union {
> +		struct list_head pt_list;
> +		struct {
> +			unsigned long _pt_pad_1;
> +			pgtable_t pmd_huge_pte;
> +		};
> +	};
> +	unsigned long _pt_s390_gaddr;
> +
> +	union {
> +		struct mm_struct *pt_mm;
> +		atomic_t pt_frag_refcount;
> +	};
> +
> +#if ALLOC_SPLIT_PTLOCKS
> +	spinlock_t *ptl;
> +#else
> +	spinlock_t ptl;
> +#endif
> +};

I think you should include the memcg here too? It needs to be valid
for a ptdesc, even if we don't currently deref it through the ptdesc
type.

Also, do you see a way to someday put a 'struct rcu_head' into here?

Thanks,
Jason

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Vishal Moola]

On Fri, Jun 16, 2023 at 5:38 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> On Mon, Jun 12, 2023 at 02:03:53PM -0700, Vishal Moola (Oracle) wrote:
> > Currently, page table information is stored within struct page. As part
> > of simplifying struct page, create struct ptdesc for page table
> > information.
> >
> > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > ---
> >  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 51 insertions(+)
> >
> > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> > index c5a51481bbb9..330de96ebfd6 100644
> > --- a/include/linux/pgtable.h
> > +++ b/include/linux/pgtable.h
> > @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
> >  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
> >  #endif /* CONFIG_MMU */
> >
> > +
> > +/**
> > + * struct ptdesc - Memory descriptor for page tables.
> > + * @__page_flags: Same as page flags. Unused for page tables.
> > + * @pt_list: List of used page tables. Used for s390 and x86.
> > + * @_pt_pad_1: Padding that aliases with page's compound head.
> > + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> > + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> > + * @pt_mm: Used for x86 pgds.
> > + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> > + * @ptl: Lock for the page table.
> > + *
> > + * This struct overlays struct page for now. Do not modify without a good
> > + * understanding of the issues.
> > + */
> > +struct ptdesc {
> > +     unsigned long __page_flags;
> > +
> > +     union {
> > +             struct list_head pt_list;
> > +             struct {
> > +                     unsigned long _pt_pad_1;
> > +                     pgtable_t pmd_huge_pte;
> > +             };
> > +     };
> > +     unsigned long _pt_s390_gaddr;
> > +
> > +     union {
> > +             struct mm_struct *pt_mm;
> > +             atomic_t pt_frag_refcount;
> > +     };
> > +
> > +#if ALLOC_SPLIT_PTLOCKS
> > +     spinlock_t *ptl;
> > +#else
> > +     spinlock_t ptl;
> > +#endif
> > +};
>
> I think you should include the memcg here too? It needs to be valid
> for a ptdesc, even if we don't currently deref it through the ptdesc
> type.

Yes, thanks for catching that! I'll add it to v5.

> Also, do you see a way to someday put a 'struct rcu_head' into here?

Eventually, when they're being dynamically allocated independent of
struct page. Although at that point I'm not sure if we'll need one.

> Thanks,
> Jason

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Jason Gunthorpe]

On Tue, Jun 20, 2023 at 01:01:39PM -0700, Vishal Moola wrote:
> On Fri, Jun 16, 2023 at 5:38 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
> >
> > On Mon, Jun 12, 2023 at 02:03:53PM -0700, Vishal Moola (Oracle) wrote:
> > > Currently, page table information is stored within struct page. As part
> > > of simplifying struct page, create struct ptdesc for page table
> > > information.
> > >
> > > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > > ---
> > >  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
> > >  1 file changed, 51 insertions(+)
> > >
> > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> > > index c5a51481bbb9..330de96ebfd6 100644
> > > --- a/include/linux/pgtable.h
> > > +++ b/include/linux/pgtable.h
> > > @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
> > >  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
> > >  #endif /* CONFIG_MMU */
> > >
> > > +
> > > +/**
> > > + * struct ptdesc - Memory descriptor for page tables.
> > > + * @__page_flags: Same as page flags. Unused for page tables.
> > > + * @pt_list: List of used page tables. Used for s390 and x86.
> > > + * @_pt_pad_1: Padding that aliases with page's compound head.
> > > + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> > > + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> > > + * @pt_mm: Used for x86 pgds.
> > > + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> > > + * @ptl: Lock for the page table.
> > > + *
> > > + * This struct overlays struct page for now. Do not modify without a good
> > > + * understanding of the issues.
> > > + */
> > > +struct ptdesc {
> > > +     unsigned long __page_flags;
> > > +
> > > +     union {
> > > +             struct list_head pt_list;
> > > +             struct {
> > > +                     unsigned long _pt_pad_1;
> > > +                     pgtable_t pmd_huge_pte;
> > > +             };
> > > +     };
> > > +     unsigned long _pt_s390_gaddr;
> > > +
> > > +     union {
> > > +             struct mm_struct *pt_mm;
> > > +             atomic_t pt_frag_refcount;
> > > +     };
> > > +
> > > +#if ALLOC_SPLIT_PTLOCKS
> > > +     spinlock_t *ptl;
> > > +#else
> > > +     spinlock_t ptl;
> > > +#endif
> > > +};
> >
> > I think you should include the memcg here too? It needs to be valid
> > for a ptdesc, even if we don't currently deref it through the ptdesc
> > type.
> 
> Yes, thanks for catching that! I'll add it to v5.
> 
> > Also, do you see a way to someday put a 'struct rcu_head' into here?
> 
> Eventually, when they're being dynamically allocated independent of
> struct page. Although at that point I'm not sure if we'll need one.

Sooner than dynamic struct page?

Probably it can overlap pt_list in alot of arches?

Jason

Re: [PATCH v4 04/34] pgtable: Create struct ptdesc

[Vishal Moola]

On Tue, Jun 20, 2023 at 4:05 PM Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> On Tue, Jun 20, 2023 at 01:01:39PM -0700, Vishal Moola wrote:
> > On Fri, Jun 16, 2023 at 5:38 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
> > >
> > > On Mon, Jun 12, 2023 at 02:03:53PM -0700, Vishal Moola (Oracle) wrote:
> > > > Currently, page table information is stored within struct page. As part
> > > > of simplifying struct page, create struct ptdesc for page table
> > > > information.
> > > >
> > > > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > > > ---
> > > >  include/linux/pgtable.h | 51 +++++++++++++++++++++++++++++++++++++++++
> > > >  1 file changed, 51 insertions(+)
> > > >
> > > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> > > > index c5a51481bbb9..330de96ebfd6 100644
> > > > --- a/include/linux/pgtable.h
> > > > +++ b/include/linux/pgtable.h
> > > > @@ -975,6 +975,57 @@ static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
> > > >  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
> > > >  #endif /* CONFIG_MMU */
> > > >
> > > > +
> > > > +/**
> > > > + * struct ptdesc - Memory descriptor for page tables.
> > > > + * @__page_flags: Same as page flags. Unused for page tables.
> > > > + * @pt_list: List of used page tables. Used for s390 and x86.
> > > > + * @_pt_pad_1: Padding that aliases with page's compound head.
> > > > + * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
> > > > + * @_pt_s390_gaddr: Aliases with page's mapping. Used for s390 gmap only.
> > > > + * @pt_mm: Used for x86 pgds.
> > > > + * @pt_frag_refcount: For fragmented page table tracking. Powerpc and s390 only.
> > > > + * @ptl: Lock for the page table.
> > > > + *
> > > > + * This struct overlays struct page for now. Do not modify without a good
> > > > + * understanding of the issues.
> > > > + */
> > > > +struct ptdesc {
> > > > +     unsigned long __page_flags;
> > > > +
> > > > +     union {
> > > > +             struct list_head pt_list;
> > > > +             struct {
> > > > +                     unsigned long _pt_pad_1;
> > > > +                     pgtable_t pmd_huge_pte;
> > > > +             };
> > > > +     };
> > > > +     unsigned long _pt_s390_gaddr;
> > > > +
> > > > +     union {
> > > > +             struct mm_struct *pt_mm;
> > > > +             atomic_t pt_frag_refcount;
> > > > +     };
> > > > +
> > > > +#if ALLOC_SPLIT_PTLOCKS
> > > > +     spinlock_t *ptl;
> > > > +#else
> > > > +     spinlock_t ptl;
> > > > +#endif
> > > > +};
> > >
> > > I think you should include the memcg here too? It needs to be valid
> > > for a ptdesc, even if we don't currently deref it through the ptdesc
> > > type.
> >
> > Yes, thanks for catching that! I'll add it to v5.
> >
> > > Also, do you see a way to someday put a 'struct rcu_head' into here?
> >
> > Eventually, when they're being dynamically allocated independent of
> > struct page. Although at that point I'm not sure if we'll need one.
>
> Sooner than dynamic struct page?
>
> Probably it can overlap pt_list in alot of arches?

Ah yes, there will be one if v5 overlapping with pt_list
(it already does in struct page anyways).

[PATCH v4 05/34] mm: add utility functions for ptdesc

[Vishal Moola (Oracle)]

Introduce utility functions setting the foundation for ptdescs. These
will also assist in the splitting out of ptdesc from struct page.

Functions that focus on the descriptor are prefixed with ptdesc_* while
functions that focus on the pagetable are prefixed with pagetable_*.

pagetable_alloc() is defined to allocate new ptdesc pages as compound
pages. This is to standardize ptdescs by allowing for one allocation
and one free function, in contrast to 2 allocation and 2 free functions.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/asm-generic/tlb.h | 11 +++++++
 include/linux/mm.h        | 61 +++++++++++++++++++++++++++++++++++++++
 include/linux/pgtable.h   | 12 ++++++++
 3 files changed, 84 insertions(+)

diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index b46617207c93..6bade9e0e799 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -481,6 +481,17 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 	return tlb_remove_page_size(tlb, page, PAGE_SIZE);
 }
 
+static inline void tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt)
+{
+	tlb_remove_table(tlb, pt);
+}
+
+/* Like tlb_remove_ptdesc, but for page-like page directories. */
+static inline void tlb_remove_page_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt)
+{
+	tlb_remove_page(tlb, ptdesc_page(pt));
+}
+
 static inline void tlb_change_page_size(struct mmu_gather *tlb,
 						     unsigned int page_size)
 {
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0db09639dd2d..f184f1eba85d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2766,6 +2766,62 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 }
 #endif /* CONFIG_MMU */
 
+static inline struct ptdesc *virt_to_ptdesc(const void *x)
+{
+	return page_ptdesc(virt_to_page(x));
+}
+
+static inline void *ptdesc_to_virt(const struct ptdesc *pt)
+{
+	return page_to_virt(ptdesc_page(pt));
+}
+
+static inline void *ptdesc_address(const struct ptdesc *pt)
+{
+	return folio_address(ptdesc_folio(pt));
+}
+
+static inline bool pagetable_is_reserved(struct ptdesc *pt)
+{
+	return folio_test_reserved(ptdesc_folio(pt));
+}
+
+/**
+ * pagetable_alloc - Allocate pagetables
+ * @gfp:    GFP flags
+ * @order:  desired pagetable order
+ *
+ * pagetable_alloc allocates a page table descriptor as well as all pages
+ * described by it.
+ *
+ * Return: The ptdesc describing the allocated page tables.
+ */
+static inline struct ptdesc *pagetable_alloc(gfp_t gfp, unsigned int order)
+{
+	struct page *page = alloc_pages(gfp | __GFP_COMP, order);
+
+	return page_ptdesc(page);
+}
+
+/**
+ * pagetable_free - Free pagetables
+ * @pt:	The page table descriptor
+ *
+ * pagetable_free frees a page table descriptor as well as all page
+ * tables described by said ptdesc.
+ */
+static inline void pagetable_free(struct ptdesc *pt)
+{
+	struct page *page = ptdesc_page(pt);
+
+	__free_pages(page, compound_order(page));
+}
+
+static inline void pagetable_clear(void *x)
+{
+	clear_page(x);
+}
+
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS
 void __init ptlock_cache_init(void);
@@ -2992,6 +3048,11 @@ static inline void mark_page_reserved(struct page *page)
 	adjust_managed_page_count(page, -1);
 }
 
+static inline void free_reserved_ptdesc(struct ptdesc *pt)
+{
+	free_reserved_page(ptdesc_page(pt));
+}
+
 /*
  * Default method to free all the __init memory into the buddy system.
  * The freed pages will be poisoned with pattern "poison" if it's within
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 330de96ebfd6..c405f74d3875 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1026,6 +1026,18 @@ TABLE_MATCH(ptl, ptl);
 #undef TABLE_MATCH
 static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
 
+#define ptdesc_page(pt)			(_Generic((pt),			\
+	const struct ptdesc *:		(const struct page *)(pt),	\
+	struct ptdesc *:		(struct page *)(pt)))
+
+#define ptdesc_folio(pt)		(_Generic((pt),			\
+	const struct ptdesc *:		(const struct folio *)(pt),	\
+	struct ptdesc *:		(struct folio *)(pt)))
+
+#define page_ptdesc(p)			(_Generic((p),			\
+	const struct page *:		(const struct ptdesc *)(p),	\
+	struct page *:			(struct ptdesc *)(p)))
+
 /*
  * No-op macros that just return the current protection value. Defined here
  * because these macros can be used even if CONFIG_MMU is not defined.
-- 
2.40.1

Re: [PATCH v4 05/34] mm: add utility functions for ptdesc

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:54PM -0700, Vishal Moola (Oracle) wrote:
> Introduce utility functions setting the foundation for ptdescs. These
> will also assist in the splitting out of ptdesc from struct page.
> 
> Functions that focus on the descriptor are prefixed with ptdesc_* while
> functions that focus on the pagetable are prefixed with pagetable_*.
> 
> pagetable_alloc() is defined to allocate new ptdesc pages as compound
> pages. This is to standardize ptdescs by allowing for one allocation
> and one free function, in contrast to 2 allocation and 2 free functions.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>  include/asm-generic/tlb.h | 11 +++++++
>  include/linux/mm.h        | 61 +++++++++++++++++++++++++++++++++++++++
>  include/linux/pgtable.h   | 12 ++++++++
>  3 files changed, 84 insertions(+)
> 
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index b46617207c93..6bade9e0e799 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -481,6 +481,17 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
>  	return tlb_remove_page_size(tlb, page, PAGE_SIZE);
>  }
>  
> +static inline void tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt)
> +{
> +	tlb_remove_table(tlb, pt);
> +}
> +
> +/* Like tlb_remove_ptdesc, but for page-like page directories. */
> +static inline void tlb_remove_page_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt)
> +{
> +	tlb_remove_page(tlb, ptdesc_page(pt));
> +}
> +
>  static inline void tlb_change_page_size(struct mmu_gather *tlb,
>  						     unsigned int page_size)
>  {
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 0db09639dd2d..f184f1eba85d 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2766,6 +2766,62 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
>  }
>  #endif /* CONFIG_MMU */
>  
> +static inline struct ptdesc *virt_to_ptdesc(const void *x)
> +{
> +	return page_ptdesc(virt_to_page(x));
> +}
> +
> +static inline void *ptdesc_to_virt(const struct ptdesc *pt)
> +{
> +	return page_to_virt(ptdesc_page(pt));
> +}
> +
> +static inline void *ptdesc_address(const struct ptdesc *pt)
> +{
> +	return folio_address(ptdesc_folio(pt));
> +}
> +
> +static inline bool pagetable_is_reserved(struct ptdesc *pt)
> +{
> +	return folio_test_reserved(ptdesc_folio(pt));
> +}
> +
> +/**
> + * pagetable_alloc - Allocate pagetables
> + * @gfp:    GFP flags
> + * @order:  desired pagetable order
> + *
> + * pagetable_alloc allocates a page table descriptor as well as all pages
> + * described by it.

I think the order should be switched here to emphasize that primarily this
method allocates memory for page tables. How about

 pagetable_alloc allocates memory for the page tables as well as a page
 table descriptor that describes the allocated memory

> + *
> + * Return: The ptdesc describing the allocated page tables.
> + */
> +static inline struct ptdesc *pagetable_alloc(gfp_t gfp, unsigned int order)
> +{
> +	struct page *page = alloc_pages(gfp | __GFP_COMP, order);
> +
> +	return page_ptdesc(page);
> +}
> +
> +/**
> + * pagetable_free - Free pagetables
> + * @pt:	The page table descriptor
> + *
> + * pagetable_free frees a page table descriptor as well as all page
> + * tables described by said ptdesc.

Similarly here.

> + */
> +static inline void pagetable_free(struct ptdesc *pt)
> +{
> +	struct page *page = ptdesc_page(pt);
> +
> +	__free_pages(page, compound_order(page));
> +}
> +
> +static inline void pagetable_clear(void *x)
> +{
> +	clear_page(x);
> +}
> +
>  #if USE_SPLIT_PTE_PTLOCKS
>  #if ALLOC_SPLIT_PTLOCKS
>  void __init ptlock_cache_init(void);
> @@ -2992,6 +3048,11 @@ static inline void mark_page_reserved(struct page *page)
>  	adjust_managed_page_count(page, -1);
>  }
>  
> +static inline void free_reserved_ptdesc(struct ptdesc *pt)
> +{
> +	free_reserved_page(ptdesc_page(pt));
> +}
> +
>  /*
>   * Default method to free all the __init memory into the buddy system.
>   * The freed pages will be poisoned with pattern "poison" if it's within
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index 330de96ebfd6..c405f74d3875 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -1026,6 +1026,18 @@ TABLE_MATCH(ptl, ptl);
>  #undef TABLE_MATCH
>  static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
>  
> +#define ptdesc_page(pt)			(_Generic((pt),			\
> +	const struct ptdesc *:		(const struct page *)(pt),	\
> +	struct ptdesc *:		(struct page *)(pt)))
> +
> +#define ptdesc_folio(pt)		(_Generic((pt),			\
> +	const struct ptdesc *:		(const struct folio *)(pt),	\
> +	struct ptdesc *:		(struct folio *)(pt)))
> +
> +#define page_ptdesc(p)			(_Generic((p),			\
> +	const struct page *:		(const struct ptdesc *)(p),	\
> +	struct page *:			(struct ptdesc *)(p)))
> +
>  /*
>   * No-op macros that just return the current protection value. Defined here
>   * because these macros can be used even if CONFIG_MMU is not defined.
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 06/34] mm: Convert pmd_pgtable_page() to pmd_ptdesc()

[Vishal Moola (Oracle)]

Converts pmd_pgtable_page() to pmd_ptdesc() and all its callers. This
removes some direct accesses to struct page, working towards splitting
out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f184f1eba85d..088b7664f897 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2931,15 +2931,15 @@ static inline void pgtable_pte_page_dtor(struct page *page)
 
 #if USE_SPLIT_PMD_PTLOCKS
 
-static inline struct page *pmd_pgtable_page(pmd_t *pmd)
+static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd)
 {
 	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
-	return virt_to_page((void *)((unsigned long) pmd & mask));
+	return virt_to_ptdesc((void *)((unsigned long) pmd & mask));
 }
 
 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
 {
-	return ptlock_ptr(pmd_pgtable_page(pmd));
+	return ptlock_ptr(ptdesc_page(pmd_ptdesc(pmd)));
 }
 
 static inline bool pmd_ptlock_init(struct page *page)
@@ -2958,7 +2958,7 @@ static inline void pmd_ptlock_free(struct page *page)
 	ptlock_free(page);
 }
 
-#define pmd_huge_pte(mm, pmd) (pmd_pgtable_page(pmd)->pmd_huge_pte)
+#define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
 
 #else
 
-- 
2.40.1

Re: [PATCH v4 06/34] mm: Convert pmd_pgtable_page() to pmd_ptdesc()

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:55PM -0700, Vishal Moola (Oracle) wrote:
> Converts pmd_pgtable_page() to pmd_ptdesc() and all its callers. This
> removes some direct accesses to struct page, working towards splitting
> out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index f184f1eba85d..088b7664f897 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2931,15 +2931,15 @@ static inline void pgtable_pte_page_dtor(struct page *page)
>  
>  #if USE_SPLIT_PMD_PTLOCKS
>  
> -static inline struct page *pmd_pgtable_page(pmd_t *pmd)
> +static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd)
>  {
>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> -	return virt_to_page((void *)((unsigned long) pmd & mask));
> +	return virt_to_ptdesc((void *)((unsigned long) pmd & mask));
>  }
>  
>  static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  {
> -	return ptlock_ptr(pmd_pgtable_page(pmd));
> +	return ptlock_ptr(ptdesc_page(pmd_ptdesc(pmd)));
>  }
>  
>  static inline bool pmd_ptlock_init(struct page *page)
> @@ -2958,7 +2958,7 @@ static inline void pmd_ptlock_free(struct page *page)
>  	ptlock_free(page);
>  }
>  
> -#define pmd_huge_pte(mm, pmd) (pmd_pgtable_page(pmd)->pmd_huge_pte)
> +#define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
>  
>  #else
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 07/34] mm: Convert ptlock_alloc() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 6 +++---
 mm/memory.c        | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 088b7664f897..e6f1be2a405e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2825,7 +2825,7 @@ static inline void pagetable_clear(void *x)
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS
 void __init ptlock_cache_init(void);
-extern bool ptlock_alloc(struct page *page);
+bool ptlock_alloc(struct ptdesc *ptdesc);
 extern void ptlock_free(struct page *page);
 
 static inline spinlock_t *ptlock_ptr(struct page *page)
@@ -2837,7 +2837,7 @@ static inline void ptlock_cache_init(void)
 {
 }
 
-static inline bool ptlock_alloc(struct page *page)
+static inline bool ptlock_alloc(struct ptdesc *ptdesc)
 {
 	return true;
 }
@@ -2867,7 +2867,7 @@ static inline bool ptlock_init(struct page *page)
 	 * slab code uses page->slab_cache, which share storage with page->ptl.
 	 */
 	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
-	if (!ptlock_alloc(page))
+	if (!ptlock_alloc(page_ptdesc(page)))
 		return false;
 	spin_lock_init(ptlock_ptr(page));
 	return true;
diff --git a/mm/memory.c b/mm/memory.c
index 80ce9dda2779..ba9579117686 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5934,14 +5934,14 @@ void __init ptlock_cache_init(void)
 			SLAB_PANIC, NULL);
 }
 
-bool ptlock_alloc(struct page *page)
+bool ptlock_alloc(struct ptdesc *ptdesc)
 {
 	spinlock_t *ptl;
 
 	ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL);
 	if (!ptl)
 		return false;
-	page->ptl = ptl;
+	ptdesc->ptl = ptl;
 	return true;
 }
 
-- 
2.40.1

Re: [PATCH v4 07/34] mm: Convert ptlock_alloc() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:56PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 6 +++---
>  mm/memory.c        | 4 ++--
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 088b7664f897..e6f1be2a405e 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2825,7 +2825,7 @@ static inline void pagetable_clear(void *x)
>  #if USE_SPLIT_PTE_PTLOCKS
>  #if ALLOC_SPLIT_PTLOCKS
>  void __init ptlock_cache_init(void);
> -extern bool ptlock_alloc(struct page *page);
> +bool ptlock_alloc(struct ptdesc *ptdesc);
>  extern void ptlock_free(struct page *page);
>  
>  static inline spinlock_t *ptlock_ptr(struct page *page)
> @@ -2837,7 +2837,7 @@ static inline void ptlock_cache_init(void)
>  {
>  }
>  
> -static inline bool ptlock_alloc(struct page *page)
> +static inline bool ptlock_alloc(struct ptdesc *ptdesc)
>  {
>  	return true;
>  }
> @@ -2867,7 +2867,7 @@ static inline bool ptlock_init(struct page *page)
>  	 * slab code uses page->slab_cache, which share storage with page->ptl.
>  	 */
>  	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
> -	if (!ptlock_alloc(page))
> +	if (!ptlock_alloc(page_ptdesc(page)))
>  		return false;
>  	spin_lock_init(ptlock_ptr(page));
>  	return true;
> diff --git a/mm/memory.c b/mm/memory.c
> index 80ce9dda2779..ba9579117686 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -5934,14 +5934,14 @@ void __init ptlock_cache_init(void)
>  			SLAB_PANIC, NULL);
>  }
>  
> -bool ptlock_alloc(struct page *page)
> +bool ptlock_alloc(struct ptdesc *ptdesc)
>  {
>  	spinlock_t *ptl;
>  
>  	ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL);
>  	if (!ptl)
>  		return false;
> -	page->ptl = ptl;
> +	ptdesc->ptl = ptl;
>  	return true;
>  }
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 08/34] mm: Convert ptlock_ptr() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/x86/xen/mmu_pv.c |  2 +-
 include/linux/mm.h    | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index b3b8d289b9ab..f469862e3ef4 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -651,7 +651,7 @@ static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
 	spinlock_t *ptl = NULL;
 
 #if USE_SPLIT_PTE_PTLOCKS
-	ptl = ptlock_ptr(page);
+	ptl = ptlock_ptr(page_ptdesc(page));
 	spin_lock_nest_lock(ptl, &mm->page_table_lock);
 #endif
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e6f1be2a405e..bb934d51390f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2828,9 +2828,9 @@ void __init ptlock_cache_init(void);
 bool ptlock_alloc(struct ptdesc *ptdesc);
 extern void ptlock_free(struct page *page);
 
-static inline spinlock_t *ptlock_ptr(struct page *page)
+static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
 {
-	return page->ptl;
+	return ptdesc->ptl;
 }
 #else /* ALLOC_SPLIT_PTLOCKS */
 static inline void ptlock_cache_init(void)
@@ -2846,15 +2846,15 @@ static inline void ptlock_free(struct page *page)
 {
 }
 
-static inline spinlock_t *ptlock_ptr(struct page *page)
+static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
 {
-	return &page->ptl;
+	return &ptdesc->ptl;
 }
 #endif /* ALLOC_SPLIT_PTLOCKS */
 
 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
 {
-	return ptlock_ptr(pmd_page(*pmd));
+	return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
 }
 
 static inline bool ptlock_init(struct page *page)
@@ -2869,7 +2869,7 @@ static inline bool ptlock_init(struct page *page)
 	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
 	if (!ptlock_alloc(page_ptdesc(page)))
 		return false;
-	spin_lock_init(ptlock_ptr(page));
+	spin_lock_init(ptlock_ptr(page_ptdesc(page)));
 	return true;
 }
 
@@ -2939,7 +2939,7 @@ static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd)
 
 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
 {
-	return ptlock_ptr(ptdesc_page(pmd_ptdesc(pmd)));
+	return ptlock_ptr(pmd_ptdesc(pmd));
 }
 
 static inline bool pmd_ptlock_init(struct page *page)
-- 
2.40.1

Re: [PATCH v4 08/34] mm: Convert ptlock_ptr() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:57PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/x86/xen/mmu_pv.c |  2 +-
>  include/linux/mm.h    | 14 +++++++-------
>  2 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
> index b3b8d289b9ab..f469862e3ef4 100644
> --- a/arch/x86/xen/mmu_pv.c
> +++ b/arch/x86/xen/mmu_pv.c
> @@ -651,7 +651,7 @@ static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
>  	spinlock_t *ptl = NULL;
>  
>  #if USE_SPLIT_PTE_PTLOCKS
> -	ptl = ptlock_ptr(page);
> +	ptl = ptlock_ptr(page_ptdesc(page));
>  	spin_lock_nest_lock(ptl, &mm->page_table_lock);
>  #endif
>  
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index e6f1be2a405e..bb934d51390f 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2828,9 +2828,9 @@ void __init ptlock_cache_init(void);
>  bool ptlock_alloc(struct ptdesc *ptdesc);
>  extern void ptlock_free(struct page *page);
>  
> -static inline spinlock_t *ptlock_ptr(struct page *page)
> +static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
>  {
> -	return page->ptl;
> +	return ptdesc->ptl;
>  }
>  #else /* ALLOC_SPLIT_PTLOCKS */
>  static inline void ptlock_cache_init(void)
> @@ -2846,15 +2846,15 @@ static inline void ptlock_free(struct page *page)
>  {
>  }
>  
> -static inline spinlock_t *ptlock_ptr(struct page *page)
> +static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
>  {
> -	return &page->ptl;
> +	return &ptdesc->ptl;
>  }
>  #endif /* ALLOC_SPLIT_PTLOCKS */
>  
>  static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  {
> -	return ptlock_ptr(pmd_page(*pmd));
> +	return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
>  }
>  
>  static inline bool ptlock_init(struct page *page)
> @@ -2869,7 +2869,7 @@ static inline bool ptlock_init(struct page *page)
>  	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
>  	if (!ptlock_alloc(page_ptdesc(page)))
>  		return false;
> -	spin_lock_init(ptlock_ptr(page));
> +	spin_lock_init(ptlock_ptr(page_ptdesc(page)));
>  	return true;
>  }
>  
> @@ -2939,7 +2939,7 @@ static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd)
>  
>  static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  {
> -	return ptlock_ptr(ptdesc_page(pmd_ptdesc(pmd)));
> +	return ptlock_ptr(pmd_ptdesc(pmd));
>  }
>  
>  static inline bool pmd_ptlock_init(struct page *page)
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 09/34] mm: Convert pmd_ptlock_init() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index bb934d51390f..daecf1db6cf1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2942,12 +2942,12 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
 	return ptlock_ptr(pmd_ptdesc(pmd));
 }
 
-static inline bool pmd_ptlock_init(struct page *page)
+static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
 {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	page->pmd_huge_pte = NULL;
+	ptdesc->pmd_huge_pte = NULL;
 #endif
-	return ptlock_init(page);
+	return ptlock_init(ptdesc_page(ptdesc));
 }
 
 static inline void pmd_ptlock_free(struct page *page)
@@ -2967,7 +2967,7 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
 	return &mm->page_table_lock;
 }
 
-static inline bool pmd_ptlock_init(struct page *page) { return true; }
+static inline bool pmd_ptlock_init(struct ptdesc *ptdesc) { return true; }
 static inline void pmd_ptlock_free(struct page *page) {}
 
 #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
@@ -2983,7 +2983,7 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
 
 static inline bool pgtable_pmd_page_ctor(struct page *page)
 {
-	if (!pmd_ptlock_init(page))
+	if (!pmd_ptlock_init(page_ptdesc(page)))
 		return false;
 	__SetPageTable(page);
 	inc_lruvec_page_state(page, NR_PAGETABLE);
-- 
2.40.1

Re: [PATCH v4 09/34] mm: Convert pmd_ptlock_init() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:58PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index bb934d51390f..daecf1db6cf1 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2942,12 +2942,12 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return ptlock_ptr(pmd_ptdesc(pmd));
>  }
>  
> -static inline bool pmd_ptlock_init(struct page *page)
> +static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
>  {
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -	page->pmd_huge_pte = NULL;
> +	ptdesc->pmd_huge_pte = NULL;
>  #endif
> -	return ptlock_init(page);
> +	return ptlock_init(ptdesc_page(ptdesc));
>  }
>  
>  static inline void pmd_ptlock_free(struct page *page)
> @@ -2967,7 +2967,7 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return &mm->page_table_lock;
>  }
>  
> -static inline bool pmd_ptlock_init(struct page *page) { return true; }
> +static inline bool pmd_ptlock_init(struct ptdesc *ptdesc) { return true; }
>  static inline void pmd_ptlock_free(struct page *page) {}
>  
>  #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
> @@ -2983,7 +2983,7 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
>  
>  static inline bool pgtable_pmd_page_ctor(struct page *page)
>  {
> -	if (!pmd_ptlock_init(page))
> +	if (!pmd_ptlock_init(page_ptdesc(page)))
>  		return false;
>  	__SetPageTable(page);
>  	inc_lruvec_page_state(page, NR_PAGETABLE);
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 10/34] mm: Convert ptlock_init() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index daecf1db6cf1..f48e626d9c98 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2857,7 +2857,7 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
 	return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
 }
 
-static inline bool ptlock_init(struct page *page)
+static inline bool ptlock_init(struct ptdesc *ptdesc)
 {
 	/*
 	 * prep_new_page() initialize page->private (and therefore page->ptl)
@@ -2866,10 +2866,10 @@ static inline bool ptlock_init(struct page *page)
 	 * It can happen if arch try to use slab for page table allocation:
 	 * slab code uses page->slab_cache, which share storage with page->ptl.
 	 */
-	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
-	if (!ptlock_alloc(page_ptdesc(page)))
+	VM_BUG_ON_PAGE(*(unsigned long *)&ptdesc->ptl, ptdesc_page(ptdesc));
+	if (!ptlock_alloc(ptdesc))
 		return false;
-	spin_lock_init(ptlock_ptr(page_ptdesc(page)));
+	spin_lock_init(ptlock_ptr(ptdesc));
 	return true;
 }
 
@@ -2882,13 +2882,13 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
 	return &mm->page_table_lock;
 }
 static inline void ptlock_cache_init(void) {}
-static inline bool ptlock_init(struct page *page) { return true; }
+static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
 static inline void ptlock_free(struct page *page) {}
 #endif /* USE_SPLIT_PTE_PTLOCKS */
 
 static inline bool pgtable_pte_page_ctor(struct page *page)
 {
-	if (!ptlock_init(page))
+	if (!ptlock_init(page_ptdesc(page)))
 		return false;
 	__SetPageTable(page);
 	inc_lruvec_page_state(page, NR_PAGETABLE);
@@ -2947,7 +2947,7 @@ static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	ptdesc->pmd_huge_pte = NULL;
 #endif
-	return ptlock_init(ptdesc_page(ptdesc));
+	return ptlock_init(ptdesc);
 }
 
 static inline void pmd_ptlock_free(struct page *page)
-- 
2.40.1

Re: [PATCH v4 10/34] mm: Convert ptlock_init() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:03:59PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index daecf1db6cf1..f48e626d9c98 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2857,7 +2857,7 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
>  }
>  
> -static inline bool ptlock_init(struct page *page)
> +static inline bool ptlock_init(struct ptdesc *ptdesc)
>  {
>  	/*
>  	 * prep_new_page() initialize page->private (and therefore page->ptl)
> @@ -2866,10 +2866,10 @@ static inline bool ptlock_init(struct page *page)
>  	 * It can happen if arch try to use slab for page table allocation:
>  	 * slab code uses page->slab_cache, which share storage with page->ptl.
>  	 */
> -	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
> -	if (!ptlock_alloc(page_ptdesc(page)))
> +	VM_BUG_ON_PAGE(*(unsigned long *)&ptdesc->ptl, ptdesc_page(ptdesc));
> +	if (!ptlock_alloc(ptdesc))
>  		return false;
> -	spin_lock_init(ptlock_ptr(page_ptdesc(page)));
> +	spin_lock_init(ptlock_ptr(ptdesc));
>  	return true;
>  }
>  
> @@ -2882,13 +2882,13 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return &mm->page_table_lock;
>  }
>  static inline void ptlock_cache_init(void) {}
> -static inline bool ptlock_init(struct page *page) { return true; }
> +static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
>  static inline void ptlock_free(struct page *page) {}
>  #endif /* USE_SPLIT_PTE_PTLOCKS */
>  
>  static inline bool pgtable_pte_page_ctor(struct page *page)
>  {
> -	if (!ptlock_init(page))
> +	if (!ptlock_init(page_ptdesc(page)))
>  		return false;
>  	__SetPageTable(page);
>  	inc_lruvec_page_state(page, NR_PAGETABLE);
> @@ -2947,7 +2947,7 @@ static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  	ptdesc->pmd_huge_pte = NULL;
>  #endif
> -	return ptlock_init(ptdesc_page(ptdesc));
> +	return ptlock_init(ptdesc);
>  }
>  
>  static inline void pmd_ptlock_free(struct page *page)
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 11/34] mm: Convert pmd_ptlock_free() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f48e626d9c98..3b54bb4c9753 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2950,12 +2950,12 @@ static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
 	return ptlock_init(ptdesc);
 }
 
-static inline void pmd_ptlock_free(struct page *page)
+static inline void pmd_ptlock_free(struct ptdesc *ptdesc)
 {
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-	VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
+	VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte, ptdesc_page(ptdesc));
 #endif
-	ptlock_free(page);
+	ptlock_free(ptdesc_page(ptdesc));
 }
 
 #define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
@@ -2968,7 +2968,7 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
 }
 
 static inline bool pmd_ptlock_init(struct ptdesc *ptdesc) { return true; }
-static inline void pmd_ptlock_free(struct page *page) {}
+static inline void pmd_ptlock_free(struct ptdesc *ptdesc) {}
 
 #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
 
@@ -2992,7 +2992,7 @@ static inline bool pgtable_pmd_page_ctor(struct page *page)
 
 static inline void pgtable_pmd_page_dtor(struct page *page)
 {
-	pmd_ptlock_free(page);
+	pmd_ptlock_free(page_ptdesc(page));
 	__ClearPageTable(page);
 	dec_lruvec_page_state(page, NR_PAGETABLE);
 }
-- 
2.40.1

Re: [PATCH v4 11/34] mm: Convert pmd_ptlock_free() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:00PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index f48e626d9c98..3b54bb4c9753 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2950,12 +2950,12 @@ static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
>  	return ptlock_init(ptdesc);
>  }
>  
> -static inline void pmd_ptlock_free(struct page *page)
> +static inline void pmd_ptlock_free(struct ptdesc *ptdesc)
>  {
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -	VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
> +	VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte, ptdesc_page(ptdesc));
>  #endif
> -	ptlock_free(page);
> +	ptlock_free(ptdesc_page(ptdesc));
>  }
>  
>  #define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
> @@ -2968,7 +2968,7 @@ static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  }
>  
>  static inline bool pmd_ptlock_init(struct ptdesc *ptdesc) { return true; }
> -static inline void pmd_ptlock_free(struct page *page) {}
> +static inline void pmd_ptlock_free(struct ptdesc *ptdesc) {}
>  
>  #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
>  
> @@ -2992,7 +2992,7 @@ static inline bool pgtable_pmd_page_ctor(struct page *page)
>  
>  static inline void pgtable_pmd_page_dtor(struct page *page)
>  {
> -	pmd_ptlock_free(page);
> +	pmd_ptlock_free(page_ptdesc(page));
>  	__ClearPageTable(page);
>  	dec_lruvec_page_state(page, NR_PAGETABLE);
>  }
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 12/34] mm: Convert ptlock_free() to use ptdescs

[Vishal Moola (Oracle)]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 10 +++++-----
 mm/memory.c        |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3b54bb4c9753..a1af7983e1bd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2826,7 +2826,7 @@ static inline void pagetable_clear(void *x)
 #if ALLOC_SPLIT_PTLOCKS
 void __init ptlock_cache_init(void);
 bool ptlock_alloc(struct ptdesc *ptdesc);
-extern void ptlock_free(struct page *page);
+void ptlock_free(struct ptdesc *ptdesc);
 
 static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
 {
@@ -2842,7 +2842,7 @@ static inline bool ptlock_alloc(struct ptdesc *ptdesc)
 	return true;
 }
 
-static inline void ptlock_free(struct page *page)
+static inline void ptlock_free(struct ptdesc *ptdesc)
 {
 }
 
@@ -2883,7 +2883,7 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
 }
 static inline void ptlock_cache_init(void) {}
 static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
-static inline void ptlock_free(struct page *page) {}
+static inline void ptlock_free(struct ptdesc *ptdesc) {}
 #endif /* USE_SPLIT_PTE_PTLOCKS */
 
 static inline bool pgtable_pte_page_ctor(struct page *page)
@@ -2897,7 +2897,7 @@ static inline bool pgtable_pte_page_ctor(struct page *page)
 
 static inline void pgtable_pte_page_dtor(struct page *page)
 {
-	ptlock_free(page);
+	ptlock_free(page_ptdesc(page));
 	__ClearPageTable(page);
 	dec_lruvec_page_state(page, NR_PAGETABLE);
 }
@@ -2955,7 +2955,7 @@ static inline void pmd_ptlock_free(struct ptdesc *ptdesc)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte, ptdesc_page(ptdesc));
 #endif
-	ptlock_free(ptdesc_page(ptdesc));
+	ptlock_free(ptdesc);
 }
 
 #define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
diff --git a/mm/memory.c b/mm/memory.c
index ba9579117686..d4d2ea5cf0fd 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5945,8 +5945,8 @@ bool ptlock_alloc(struct ptdesc *ptdesc)
 	return true;
 }
 
-void ptlock_free(struct page *page)
+void ptlock_free(struct ptdesc *ptdesc)
 {
-	kmem_cache_free(page_ptl_cachep, page->ptl);
+	kmem_cache_free(page_ptl_cachep, ptdesc->ptl);
 }
 #endif
-- 
2.40.1

Re: [PATCH v4 12/34] mm: Convert ptlock_free() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:01PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 10 +++++-----
>  mm/memory.c        |  4 ++--
>  2 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 3b54bb4c9753..a1af7983e1bd 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2826,7 +2826,7 @@ static inline void pagetable_clear(void *x)
>  #if ALLOC_SPLIT_PTLOCKS
>  void __init ptlock_cache_init(void);
>  bool ptlock_alloc(struct ptdesc *ptdesc);
> -extern void ptlock_free(struct page *page);
> +void ptlock_free(struct ptdesc *ptdesc);
>  
>  static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
>  {
> @@ -2842,7 +2842,7 @@ static inline bool ptlock_alloc(struct ptdesc *ptdesc)
>  	return true;
>  }
>  
> -static inline void ptlock_free(struct page *page)
> +static inline void ptlock_free(struct ptdesc *ptdesc)
>  {
>  }
>  
> @@ -2883,7 +2883,7 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  }
>  static inline void ptlock_cache_init(void) {}
>  static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
> -static inline void ptlock_free(struct page *page) {}
> +static inline void ptlock_free(struct ptdesc *ptdesc) {}
>  #endif /* USE_SPLIT_PTE_PTLOCKS */
>  
>  static inline bool pgtable_pte_page_ctor(struct page *page)
> @@ -2897,7 +2897,7 @@ static inline bool pgtable_pte_page_ctor(struct page *page)
>  
>  static inline void pgtable_pte_page_dtor(struct page *page)
>  {
> -	ptlock_free(page);
> +	ptlock_free(page_ptdesc(page));
>  	__ClearPageTable(page);
>  	dec_lruvec_page_state(page, NR_PAGETABLE);
>  }
> @@ -2955,7 +2955,7 @@ static inline void pmd_ptlock_free(struct ptdesc *ptdesc)
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  	VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte, ptdesc_page(ptdesc));
>  #endif
> -	ptlock_free(ptdesc_page(ptdesc));
> +	ptlock_free(ptdesc);
>  }
>  
>  #define pmd_huge_pte(mm, pmd) (pmd_ptdesc(pmd)->pmd_huge_pte)
> diff --git a/mm/memory.c b/mm/memory.c
> index ba9579117686..d4d2ea5cf0fd 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -5945,8 +5945,8 @@ bool ptlock_alloc(struct ptdesc *ptdesc)
>  	return true;
>  }
>  
> -void ptlock_free(struct page *page)
> +void ptlock_free(struct ptdesc *ptdesc)
>  {
> -	kmem_cache_free(page_ptl_cachep, page->ptl);
> +	kmem_cache_free(page_ptl_cachep, ptdesc->ptl);
>  }
>  #endif
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 13/34] mm: Create ptdesc equivalents for pgtable_{pte,pmd}_page_{ctor,dtor}

[Vishal Moola (Oracle)]

Creates pagetable_pte_ctor(), pagetable_pmd_ctor(), pagetable_pte_dtor(),
and pagetable_pmd_dtor() and make the original pgtable
constructor/destructors wrappers.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 56 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 14 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a1af7983e1bd..dc211c43610b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2886,20 +2886,34 @@ static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
 static inline void ptlock_free(struct ptdesc *ptdesc) {}
 #endif /* USE_SPLIT_PTE_PTLOCKS */
 
-static inline bool pgtable_pte_page_ctor(struct page *page)
+static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc)
 {
-	if (!ptlock_init(page_ptdesc(page)))
+	struct folio *folio = ptdesc_folio(ptdesc);
+
+	if (!ptlock_init(ptdesc))
 		return false;
-	__SetPageTable(page);
-	inc_lruvec_page_state(page, NR_PAGETABLE);
+	__folio_set_table(folio);
+	lruvec_stat_add_folio(folio, NR_PAGETABLE);
 	return true;
 }
 
+static inline bool pgtable_pte_page_ctor(struct page *page)
+{
+	return pagetable_pte_ctor(page_ptdesc(page));
+}
+
+static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
+{
+	struct folio *folio = ptdesc_folio(ptdesc);
+
+	ptlock_free(ptdesc);
+	__folio_clear_table(folio);
+	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
+}
+
 static inline void pgtable_pte_page_dtor(struct page *page)
 {
-	ptlock_free(page_ptdesc(page));
-	__ClearPageTable(page);
-	dec_lruvec_page_state(page, NR_PAGETABLE);
+	pagetable_pte_dtor(page_ptdesc(page));
 }
 
 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
@@ -2981,20 +2995,34 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
 	return ptl;
 }
 
-static inline bool pgtable_pmd_page_ctor(struct page *page)
+static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc)
 {
-	if (!pmd_ptlock_init(page_ptdesc(page)))
+	struct folio *folio = ptdesc_folio(ptdesc);
+
+	if (!pmd_ptlock_init(ptdesc))
 		return false;
-	__SetPageTable(page);
-	inc_lruvec_page_state(page, NR_PAGETABLE);
+	__folio_set_table(folio);
+	lruvec_stat_add_folio(folio, NR_PAGETABLE);
 	return true;
 }
 
+static inline bool pgtable_pmd_page_ctor(struct page *page)
+{
+	return pagetable_pmd_ctor(page_ptdesc(page));
+}
+
+static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
+{
+	struct folio *folio = ptdesc_folio(ptdesc);
+
+	pmd_ptlock_free(ptdesc);
+	__folio_clear_table(folio);
+	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
+}
+
 static inline void pgtable_pmd_page_dtor(struct page *page)
 {
-	pmd_ptlock_free(page_ptdesc(page));
-	__ClearPageTable(page);
-	dec_lruvec_page_state(page, NR_PAGETABLE);
+	pagetable_pmd_dtor(page_ptdesc(page));
 }
 
 /*
-- 
2.40.1

Re: [PATCH v4 13/34] mm: Create ptdesc equivalents for pgtable_{pte,pmd}_page_{ctor,dtor}

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:02PM -0700, Vishal Moola (Oracle) wrote:
> Creates pagetable_pte_ctor(), pagetable_pmd_ctor(), pagetable_pte_dtor(),
> and pagetable_pmd_dtor() and make the original pgtable
> constructor/destructors wrappers.

Nit: either "creates ... makes" or "create ... make"
I like the second form more.
 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm.h | 56 ++++++++++++++++++++++++++++++++++------------
>  1 file changed, 42 insertions(+), 14 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index a1af7983e1bd..dc211c43610b 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2886,20 +2886,34 @@ static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
>  static inline void ptlock_free(struct ptdesc *ptdesc) {}
>  #endif /* USE_SPLIT_PTE_PTLOCKS */
>  
> -static inline bool pgtable_pte_page_ctor(struct page *page)
> +static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc)
>  {
> -	if (!ptlock_init(page_ptdesc(page)))
> +	struct folio *folio = ptdesc_folio(ptdesc);
> +
> +	if (!ptlock_init(ptdesc))
>  		return false;
> -	__SetPageTable(page);
> -	inc_lruvec_page_state(page, NR_PAGETABLE);
> +	__folio_set_table(folio);

This comment is more to patch 1 ("mm: Add PAGE_TYPE_OP folio functions")

It would be better to have _pgtable here, as "table" does not necessary
mean page table.
With PageType SetPageTable was fine, but with folio I think it should be
more explicit.

I'd add a third parameter to PAGE_TYPE_OPS for that.

> +	lruvec_stat_add_folio(folio, NR_PAGETABLE);
>  	return true;
>  }
>  
> +static inline bool pgtable_pte_page_ctor(struct page *page)
> +{
> +	return pagetable_pte_ctor(page_ptdesc(page));
> +}
> +
> +static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
> +{
> +	struct folio *folio = ptdesc_folio(ptdesc);
> +
> +	ptlock_free(ptdesc);
> +	__folio_clear_table(folio);
> +	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
> +}
> +
>  static inline void pgtable_pte_page_dtor(struct page *page)
>  {
> -	ptlock_free(page_ptdesc(page));
> -	__ClearPageTable(page);
> -	dec_lruvec_page_state(page, NR_PAGETABLE);
> +	pagetable_pte_dtor(page_ptdesc(page));
>  }
>  
>  #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
> @@ -2981,20 +2995,34 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
>  	return ptl;
>  }
>  
> -static inline bool pgtable_pmd_page_ctor(struct page *page)
> +static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc)
>  {
> -	if (!pmd_ptlock_init(page_ptdesc(page)))
> +	struct folio *folio = ptdesc_folio(ptdesc);
> +
> +	if (!pmd_ptlock_init(ptdesc))
>  		return false;
> -	__SetPageTable(page);
> -	inc_lruvec_page_state(page, NR_PAGETABLE);
> +	__folio_set_table(folio);
> +	lruvec_stat_add_folio(folio, NR_PAGETABLE);
>  	return true;
>  }
>  
> +static inline bool pgtable_pmd_page_ctor(struct page *page)
> +{
> +	return pagetable_pmd_ctor(page_ptdesc(page));
> +}
> +
> +static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
> +{
> +	struct folio *folio = ptdesc_folio(ptdesc);
> +
> +	pmd_ptlock_free(ptdesc);
> +	__folio_clear_table(folio);
> +	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
> +}
> +
>  static inline void pgtable_pmd_page_dtor(struct page *page)
>  {
> -	pmd_ptlock_free(page_ptdesc(page));
> -	__ClearPageTable(page);
> -	dec_lruvec_page_state(page, NR_PAGETABLE);
> +	pagetable_pmd_dtor(page_ptdesc(page));
>  }
>  
>  /*
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 14/34] powerpc: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

In order to split struct ptdesc from struct page, convert various
functions to use ptdescs.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/powerpc/mm/book3s64/mmu_context.c | 10 +++---
 arch/powerpc/mm/book3s64/pgtable.c     | 32 +++++++++---------
 arch/powerpc/mm/pgtable-frag.c         | 46 +++++++++++++-------------
 3 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
index c766e4c26e42..1715b07c630c 100644
--- a/arch/powerpc/mm/book3s64/mmu_context.c
+++ b/arch/powerpc/mm/book3s64/mmu_context.c
@@ -246,15 +246,15 @@ static void destroy_contexts(mm_context_t *ctx)
 static void pmd_frag_destroy(void *pmd_frag)
 {
 	int count;
-	struct page *page;
+	struct ptdesc *ptdesc;
 
-	page = virt_to_page(pmd_frag);
+	ptdesc = virt_to_ptdesc(pmd_frag);
 	/* drop all the pending references */
 	count = ((unsigned long)pmd_frag & ~PAGE_MASK) >> PMD_FRAG_SIZE_SHIFT;
 	/* We allow PTE_FRAG_NR fragments from a PTE page */
-	if (atomic_sub_and_test(PMD_FRAG_NR - count, &page->pt_frag_refcount)) {
-		pgtable_pmd_page_dtor(page);
-		__free_page(page);
+	if (atomic_sub_and_test(PMD_FRAG_NR - count, &ptdesc->pt_frag_refcount)) {
+		pagetable_pmd_dtor(ptdesc);
+		pagetable_free(ptdesc);
 	}
 }
 
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 85c84e89e3ea..1212deeabe15 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -306,22 +306,22 @@ static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
 static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
 {
 	void *ret = NULL;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
 
 	if (mm == &init_mm)
 		gfp &= ~__GFP_ACCOUNT;
-	page = alloc_page(gfp);
-	if (!page)
+	ptdesc = pagetable_alloc(gfp, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pmd_page_ctor(page)) {
-		__free_pages(page, 0);
+	if (!pagetable_pmd_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	atomic_set(&page->pt_frag_refcount, 1);
+	atomic_set(&ptdesc->pt_frag_refcount, 1);
 
-	ret = page_address(page);
+	ret = ptdesc_address(ptdesc);
 	/*
 	 * if we support only one fragment just return the
 	 * allocated page.
@@ -331,12 +331,12 @@ static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
 
 	spin_lock(&mm->page_table_lock);
 	/*
-	 * If we find pgtable_page set, we return
+	 * If we find ptdesc_page set, we return
 	 * the allocated page with single fragment
 	 * count.
 	 */
 	if (likely(!mm->context.pmd_frag)) {
-		atomic_set(&page->pt_frag_refcount, PMD_FRAG_NR);
+		atomic_set(&ptdesc->pt_frag_refcount, PMD_FRAG_NR);
 		mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
 	}
 	spin_unlock(&mm->page_table_lock);
@@ -357,15 +357,15 @@ pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
 
 void pmd_fragment_free(unsigned long *pmd)
 {
-	struct page *page = virt_to_page(pmd);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
 
-	if (PageReserved(page))
-		return free_reserved_page(page);
+	if (pagetable_is_reserved(ptdesc))
+		return free_reserved_ptdesc(ptdesc);
 
-	BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
-	if (atomic_dec_and_test(&page->pt_frag_refcount)) {
-		pgtable_pmd_page_dtor(page);
-		__free_page(page);
+	BUG_ON(atomic_read(&ptdesc->pt_frag_refcount) <= 0);
+	if (atomic_dec_and_test(&ptdesc->pt_frag_refcount)) {
+		pagetable_pmd_dtor(ptdesc);
+		pagetable_free(ptdesc);
 	}
 }
 
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index 20652daa1d7e..8961f1540209 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -18,15 +18,15 @@
 void pte_frag_destroy(void *pte_frag)
 {
 	int count;
-	struct page *page;
+	struct ptdesc *ptdesc;
 
-	page = virt_to_page(pte_frag);
+	ptdesc = virt_to_ptdesc(pte_frag);
 	/* drop all the pending references */
 	count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
 	/* We allow PTE_FRAG_NR fragments from a PTE page */
-	if (atomic_sub_and_test(PTE_FRAG_NR - count, &page->pt_frag_refcount)) {
-		pgtable_pte_page_dtor(page);
-		__free_page(page);
+	if (atomic_sub_and_test(PTE_FRAG_NR - count, &ptdesc->pt_frag_refcount)) {
+		pagetable_pte_dtor(ptdesc);
+		pagetable_free(ptdesc);
 	}
 }
 
@@ -55,25 +55,25 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm)
 static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
 {
 	void *ret = NULL;
-	struct page *page;
+	struct ptdesc *ptdesc;
 
 	if (!kernel) {
-		page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
-		if (!page)
+		ptdesc = pagetable_alloc(PGALLOC_GFP | __GFP_ACCOUNT, 0);
+		if (!ptdesc)
 			return NULL;
-		if (!pgtable_pte_page_ctor(page)) {
-			__free_page(page);
+		if (!pagetable_pte_ctor(ptdesc)) {
+			pagetable_free(ptdesc);
 			return NULL;
 		}
 	} else {
-		page = alloc_page(PGALLOC_GFP);
-		if (!page)
+		ptdesc = pagetable_alloc(PGALLOC_GFP, 0);
+		if (!ptdesc)
 			return NULL;
 	}
 
-	atomic_set(&page->pt_frag_refcount, 1);
+	atomic_set(&ptdesc->pt_frag_refcount, 1);
 
-	ret = page_address(page);
+	ret = ptdesc_address(ptdesc);
 	/*
 	 * if we support only one fragment just return the
 	 * allocated page.
@@ -82,12 +82,12 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
 		return ret;
 	spin_lock(&mm->page_table_lock);
 	/*
-	 * If we find pgtable_page set, we return
+	 * If we find ptdesc_page set, we return
 	 * the allocated page with single fragment
 	 * count.
 	 */
 	if (likely(!pte_frag_get(&mm->context))) {
-		atomic_set(&page->pt_frag_refcount, PTE_FRAG_NR);
+		atomic_set(&ptdesc->pt_frag_refcount, PTE_FRAG_NR);
 		pte_frag_set(&mm->context, ret + PTE_FRAG_SIZE);
 	}
 	spin_unlock(&mm->page_table_lock);
@@ -108,15 +108,15 @@ pte_t *pte_fragment_alloc(struct mm_struct *mm, int kernel)
 
 void pte_fragment_free(unsigned long *table, int kernel)
 {
-	struct page *page = virt_to_page(table);
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
-	if (PageReserved(page))
-		return free_reserved_page(page);
+	if (pagetable_is_reserved(ptdesc))
+		return free_reserved_ptdesc(ptdesc);
 
-	BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
-	if (atomic_dec_and_test(&page->pt_frag_refcount)) {
+	BUG_ON(atomic_read(&ptdesc->pt_frag_refcount) <= 0);
+	if (atomic_dec_and_test(&ptdesc->pt_frag_refcount)) {
 		if (!kernel)
-			pgtable_pte_page_dtor(page);
-		__free_page(page);
+			pagetable_pte_dtor(ptdesc);
+		pagetable_free(ptdesc);
 	}
 }
-- 
2.40.1

Re: [PATCH v4 14/34] powerpc: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:03PM -0700, Vishal Moola (Oracle) wrote:
> In order to split struct ptdesc from struct page, convert various
> functions to use ptdescs.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/powerpc/mm/book3s64/mmu_context.c | 10 +++---
>  arch/powerpc/mm/book3s64/pgtable.c     | 32 +++++++++---------
>  arch/powerpc/mm/pgtable-frag.c         | 46 +++++++++++++-------------
>  3 files changed, 44 insertions(+), 44 deletions(-)
> 
> diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
> index c766e4c26e42..1715b07c630c 100644
> --- a/arch/powerpc/mm/book3s64/mmu_context.c
> +++ b/arch/powerpc/mm/book3s64/mmu_context.c
> @@ -246,15 +246,15 @@ static void destroy_contexts(mm_context_t *ctx)
>  static void pmd_frag_destroy(void *pmd_frag)
>  {
>  	int count;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  
> -	page = virt_to_page(pmd_frag);
> +	ptdesc = virt_to_ptdesc(pmd_frag);
>  	/* drop all the pending references */
>  	count = ((unsigned long)pmd_frag & ~PAGE_MASK) >> PMD_FRAG_SIZE_SHIFT;
>  	/* We allow PTE_FRAG_NR fragments from a PTE page */
> -	if (atomic_sub_and_test(PMD_FRAG_NR - count, &page->pt_frag_refcount)) {
> -		pgtable_pmd_page_dtor(page);
> -		__free_page(page);
> +	if (atomic_sub_and_test(PMD_FRAG_NR - count, &ptdesc->pt_frag_refcount)) {
> +		pagetable_pmd_dtor(ptdesc);
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> index 85c84e89e3ea..1212deeabe15 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -306,22 +306,22 @@ static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
>  static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
>  {
>  	void *ret = NULL;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
>  
>  	if (mm == &init_mm)
>  		gfp &= ~__GFP_ACCOUNT;
> -	page = alloc_page(gfp);
> -	if (!page)
> +	ptdesc = pagetable_alloc(gfp, 0);
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pmd_page_ctor(page)) {
> -		__free_pages(page, 0);
> +	if (!pagetable_pmd_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	atomic_set(&page->pt_frag_refcount, 1);
> +	atomic_set(&ptdesc->pt_frag_refcount, 1);
>  
> -	ret = page_address(page);
> +	ret = ptdesc_address(ptdesc);
>  	/*
>  	 * if we support only one fragment just return the
>  	 * allocated page.
> @@ -331,12 +331,12 @@ static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
>  
>  	spin_lock(&mm->page_table_lock);
>  	/*
> -	 * If we find pgtable_page set, we return
> +	 * If we find ptdesc_page set, we return
>  	 * the allocated page with single fragment
>  	 * count.
>  	 */
>  	if (likely(!mm->context.pmd_frag)) {
> -		atomic_set(&page->pt_frag_refcount, PMD_FRAG_NR);
> +		atomic_set(&ptdesc->pt_frag_refcount, PMD_FRAG_NR);
>  		mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
>  	}
>  	spin_unlock(&mm->page_table_lock);
> @@ -357,15 +357,15 @@ pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
>  
>  void pmd_fragment_free(unsigned long *pmd)
>  {
> -	struct page *page = virt_to_page(pmd);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
>  
> -	if (PageReserved(page))
> -		return free_reserved_page(page);
> +	if (pagetable_is_reserved(ptdesc))
> +		return free_reserved_ptdesc(ptdesc);
>  
> -	BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
> -	if (atomic_dec_and_test(&page->pt_frag_refcount)) {
> -		pgtable_pmd_page_dtor(page);
> -		__free_page(page);
> +	BUG_ON(atomic_read(&ptdesc->pt_frag_refcount) <= 0);
> +	if (atomic_dec_and_test(&ptdesc->pt_frag_refcount)) {
> +		pagetable_pmd_dtor(ptdesc);
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
> index 20652daa1d7e..8961f1540209 100644
> --- a/arch/powerpc/mm/pgtable-frag.c
> +++ b/arch/powerpc/mm/pgtable-frag.c
> @@ -18,15 +18,15 @@
>  void pte_frag_destroy(void *pte_frag)
>  {
>  	int count;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  
> -	page = virt_to_page(pte_frag);
> +	ptdesc = virt_to_ptdesc(pte_frag);
>  	/* drop all the pending references */
>  	count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
>  	/* We allow PTE_FRAG_NR fragments from a PTE page */
> -	if (atomic_sub_and_test(PTE_FRAG_NR - count, &page->pt_frag_refcount)) {
> -		pgtable_pte_page_dtor(page);
> -		__free_page(page);
> +	if (atomic_sub_and_test(PTE_FRAG_NR - count, &ptdesc->pt_frag_refcount)) {
> +		pagetable_pte_dtor(ptdesc);
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> @@ -55,25 +55,25 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm)
>  static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
>  {
>  	void *ret = NULL;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	if (!kernel) {
> -		page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
> -		if (!page)
> +		ptdesc = pagetable_alloc(PGALLOC_GFP | __GFP_ACCOUNT, 0);
> +		if (!ptdesc)
>  			return NULL;
> -		if (!pgtable_pte_page_ctor(page)) {
> -			__free_page(page);
> +		if (!pagetable_pte_ctor(ptdesc)) {
> +			pagetable_free(ptdesc);
>  			return NULL;
>  		}
>  	} else {
> -		page = alloc_page(PGALLOC_GFP);
> -		if (!page)
> +		ptdesc = pagetable_alloc(PGALLOC_GFP, 0);
> +		if (!ptdesc)
>  			return NULL;
>  	}
>  
> -	atomic_set(&page->pt_frag_refcount, 1);
> +	atomic_set(&ptdesc->pt_frag_refcount, 1);
>  
> -	ret = page_address(page);
> +	ret = ptdesc_address(ptdesc);
>  	/*
>  	 * if we support only one fragment just return the
>  	 * allocated page.
> @@ -82,12 +82,12 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
>  		return ret;
>  	spin_lock(&mm->page_table_lock);
>  	/*
> -	 * If we find pgtable_page set, we return
> +	 * If we find ptdesc_page set, we return
>  	 * the allocated page with single fragment
>  	 * count.
>  	 */
>  	if (likely(!pte_frag_get(&mm->context))) {
> -		atomic_set(&page->pt_frag_refcount, PTE_FRAG_NR);
> +		atomic_set(&ptdesc->pt_frag_refcount, PTE_FRAG_NR);
>  		pte_frag_set(&mm->context, ret + PTE_FRAG_SIZE);
>  	}
>  	spin_unlock(&mm->page_table_lock);
> @@ -108,15 +108,15 @@ pte_t *pte_fragment_alloc(struct mm_struct *mm, int kernel)
>  
>  void pte_fragment_free(unsigned long *table, int kernel)
>  {
> -	struct page *page = virt_to_page(table);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(table);
>  
> -	if (PageReserved(page))
> -		return free_reserved_page(page);
> +	if (pagetable_is_reserved(ptdesc))
> +		return free_reserved_ptdesc(ptdesc);
>  
> -	BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
> -	if (atomic_dec_and_test(&page->pt_frag_refcount)) {
> +	BUG_ON(atomic_read(&ptdesc->pt_frag_refcount) <= 0);
> +	if (atomic_dec_and_test(&ptdesc->pt_frag_refcount)) {
>  		if (!kernel)
> -			pgtable_pte_page_dtor(page);
> -		__free_page(page);
> +			pagetable_pte_dtor(ptdesc);
> +		pagetable_free(ptdesc);
>  	}
>  }
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 15/34] x86: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

In order to split struct ptdesc from struct page, convert various
functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/x86/mm/pgtable.c | 46 +++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 15a8009a4480..6da7fd5d4782 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -52,7 +52,7 @@ early_param("userpte", setup_userpte);
 
 void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
 {
-	pgtable_pte_page_dtor(pte);
+	pagetable_pte_dtor(page_ptdesc(pte));
 	paravirt_release_pte(page_to_pfn(pte));
 	paravirt_tlb_remove_table(tlb, pte);
 }
@@ -60,7 +60,7 @@ void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
 #if CONFIG_PGTABLE_LEVELS > 2
 void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
 {
-	struct page *page = virt_to_page(pmd);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
 	paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
 	/*
 	 * NOTE! For PAE, any changes to the top page-directory-pointer-table
@@ -69,8 +69,8 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
 #ifdef CONFIG_X86_PAE
 	tlb->need_flush_all = 1;
 #endif
-	pgtable_pmd_page_dtor(page);
-	paravirt_tlb_remove_table(tlb, page);
+	pagetable_pmd_dtor(ptdesc);
+	paravirt_tlb_remove_table(tlb, ptdesc_page(ptdesc));
 }
 
 #if CONFIG_PGTABLE_LEVELS > 3
@@ -92,16 +92,16 @@ void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)
 
 static inline void pgd_list_add(pgd_t *pgd)
 {
-	struct page *page = virt_to_page(pgd);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pgd);
 
-	list_add(&page->lru, &pgd_list);
+	list_add(&ptdesc->pt_list, &pgd_list);
 }
 
 static inline void pgd_list_del(pgd_t *pgd)
 {
-	struct page *page = virt_to_page(pgd);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pgd);
 
-	list_del(&page->lru);
+	list_del(&ptdesc->pt_list);
 }
 
 #define UNSHARED_PTRS_PER_PGD				\
@@ -112,12 +112,12 @@ static inline void pgd_list_del(pgd_t *pgd)
 
 static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
 {
-	virt_to_page(pgd)->pt_mm = mm;
+	virt_to_ptdesc(pgd)->pt_mm = mm;
 }
 
 struct mm_struct *pgd_page_get_mm(struct page *page)
 {
-	return page->pt_mm;
+	return page_ptdesc(page)->pt_mm;
 }
 
 static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
@@ -213,11 +213,14 @@ void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
 static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
 {
 	int i;
+	struct ptdesc *ptdesc;
 
 	for (i = 0; i < count; i++)
 		if (pmds[i]) {
-			pgtable_pmd_page_dtor(virt_to_page(pmds[i]));
-			free_page((unsigned long)pmds[i]);
+			ptdesc = virt_to_ptdesc(pmds[i]);
+
+			pagetable_pmd_dtor(ptdesc);
+			pagetable_free(ptdesc);
 			mm_dec_nr_pmds(mm);
 		}
 }
@@ -232,16 +235,21 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
 		gfp &= ~__GFP_ACCOUNT;
 
 	for (i = 0; i < count; i++) {
-		pmd_t *pmd = (pmd_t *)__get_free_page(gfp);
-		if (!pmd)
+		pmd_t *pmd = NULL;
+		struct ptdesc *ptdesc = pagetable_alloc(gfp, 0);
+
+		if (!ptdesc)
 			failed = true;
-		if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
-			free_page((unsigned long)pmd);
-			pmd = NULL;
+		if (ptdesc && !pagetable_pmd_ctor(ptdesc)) {
+			pagetable_free(ptdesc);
+			ptdesc = NULL;
 			failed = true;
 		}
-		if (pmd)
+		if (ptdesc) {
 			mm_inc_nr_pmds(mm);
+			pmd = ptdesc_address(ptdesc);
+		}
+
 		pmds[i] = pmd;
 	}
 
@@ -830,7 +838,7 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr)
 
 	free_page((unsigned long)pmd_sv);
 
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
 	free_page((unsigned long)pmd);
 
 	return 1;
-- 
2.40.1

Re: [PATCH v4 15/34] x86: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:04PM -0700, Vishal Moola (Oracle) wrote:
> In order to split struct ptdesc from struct page, convert various
> functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert

Nit:                           *get_free_page*()

> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.

More importantly, get_free_pages() ensures a page won't be allocated from
HIGHMEM, and for 32-bits this is a must.
 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>  arch/x86/mm/pgtable.c | 46 +++++++++++++++++++++++++------------------
>  1 file changed, 27 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
> index 15a8009a4480..6da7fd5d4782 100644
> --- a/arch/x86/mm/pgtable.c
> +++ b/arch/x86/mm/pgtable.c
> @@ -52,7 +52,7 @@ early_param("userpte", setup_userpte);
>  
>  void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
>  {
> -	pgtable_pte_page_dtor(pte);
> +	pagetable_pte_dtor(page_ptdesc(pte));
>  	paravirt_release_pte(page_to_pfn(pte));
>  	paravirt_tlb_remove_table(tlb, pte);
>  }
> @@ -60,7 +60,7 @@ void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte)
>  #if CONFIG_PGTABLE_LEVELS > 2
>  void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
>  {
> -	struct page *page = virt_to_page(pmd);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
>  	paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT);
>  	/*
>  	 * NOTE! For PAE, any changes to the top page-directory-pointer-table
> @@ -69,8 +69,8 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
>  #ifdef CONFIG_X86_PAE
>  	tlb->need_flush_all = 1;
>  #endif
> -	pgtable_pmd_page_dtor(page);
> -	paravirt_tlb_remove_table(tlb, page);
> +	pagetable_pmd_dtor(ptdesc);
> +	paravirt_tlb_remove_table(tlb, ptdesc_page(ptdesc));
>  }
>  
>  #if CONFIG_PGTABLE_LEVELS > 3
> @@ -92,16 +92,16 @@ void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)
>  
>  static inline void pgd_list_add(pgd_t *pgd)
>  {
> -	struct page *page = virt_to_page(pgd);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pgd);
>  
> -	list_add(&page->lru, &pgd_list);
> +	list_add(&ptdesc->pt_list, &pgd_list);
>  }
>  
>  static inline void pgd_list_del(pgd_t *pgd)
>  {
> -	struct page *page = virt_to_page(pgd);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pgd);
>  
> -	list_del(&page->lru);
> +	list_del(&ptdesc->pt_list);
>  }
>  
>  #define UNSHARED_PTRS_PER_PGD				\
> @@ -112,12 +112,12 @@ static inline void pgd_list_del(pgd_t *pgd)
>  
>  static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
>  {
> -	virt_to_page(pgd)->pt_mm = mm;
> +	virt_to_ptdesc(pgd)->pt_mm = mm;
>  }
>  
>  struct mm_struct *pgd_page_get_mm(struct page *page)
>  {
> -	return page->pt_mm;
> +	return page_ptdesc(page)->pt_mm;
>  }
>  
>  static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd)
> @@ -213,11 +213,14 @@ void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd)
>  static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
>  {
>  	int i;
> +	struct ptdesc *ptdesc;
>  
>  	for (i = 0; i < count; i++)
>  		if (pmds[i]) {
> -			pgtable_pmd_page_dtor(virt_to_page(pmds[i]));
> -			free_page((unsigned long)pmds[i]);
> +			ptdesc = virt_to_ptdesc(pmds[i]);
> +
> +			pagetable_pmd_dtor(ptdesc);
> +			pagetable_free(ptdesc);
>  			mm_dec_nr_pmds(mm);
>  		}
>  }
> @@ -232,16 +235,21 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
>  		gfp &= ~__GFP_ACCOUNT;
>  
>  	for (i = 0; i < count; i++) {
> -		pmd_t *pmd = (pmd_t *)__get_free_page(gfp);
> -		if (!pmd)
> +		pmd_t *pmd = NULL;
> +		struct ptdesc *ptdesc = pagetable_alloc(gfp, 0);
> +
> +		if (!ptdesc)
>  			failed = true;
> -		if (pmd && !pgtable_pmd_page_ctor(virt_to_page(pmd))) {
> -			free_page((unsigned long)pmd);
> -			pmd = NULL;
> +		if (ptdesc && !pagetable_pmd_ctor(ptdesc)) {
> +			pagetable_free(ptdesc);
> +			ptdesc = NULL;
>  			failed = true;
>  		}
> -		if (pmd)
> +		if (ptdesc) {
>  			mm_inc_nr_pmds(mm);
> +			pmd = ptdesc_address(ptdesc);
> +		}
> +
>  		pmds[i] = pmd;
>  	}
>  
> @@ -830,7 +838,7 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr)
>  
>  	free_page((unsigned long)pmd_sv);
>  
> -	pgtable_pmd_page_dtor(virt_to_page(pmd));
> +	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
>  	free_page((unsigned long)pmd);
>  
>  	return 1;
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 16/34] s390: Convert various gmap functions to use ptdescs

[Vishal Moola (Oracle)]

In order to split struct ptdesc from struct page, convert various
functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/s390/mm/gmap.c | 230 ++++++++++++++++++++++++--------------------
 1 file changed, 128 insertions(+), 102 deletions(-)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 81c683426b49..010e87df7299 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -34,7 +34,7 @@
 static struct gmap *gmap_alloc(unsigned long limit)
 {
 	struct gmap *gmap;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned long *table;
 	unsigned long etype, atype;
 
@@ -67,12 +67,12 @@ static struct gmap *gmap_alloc(unsigned long limit)
 	spin_lock_init(&gmap->guest_table_lock);
 	spin_lock_init(&gmap->shadow_lock);
 	refcount_set(&gmap->ref_count, 1);
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		goto out_free;
-	page->_pt_s390_gaddr = 0;
-	list_add(&page->lru, &gmap->crst_list);
-	table = page_to_virt(page);
+	ptdesc->_pt_s390_gaddr = 0;
+	list_add(&ptdesc->pt_list, &gmap->crst_list);
+	table = ptdesc_to_virt(ptdesc);
 	crst_table_init(table, etype);
 	gmap->table = table;
 	gmap->asce = atype | _ASCE_TABLE_LENGTH |
@@ -181,25 +181,25 @@ static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
  */
 static void gmap_free(struct gmap *gmap)
 {
-	struct page *page, *next;
+	struct ptdesc *ptdesc, *next;
 
 	/* Flush tlb of all gmaps (if not already done for shadows) */
 	if (!(gmap_is_shadow(gmap) && gmap->removed))
 		gmap_flush_tlb(gmap);
 	/* Free all segment & region tables. */
-	list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
-		page->_pt_s390_gaddr = 0;
-		__free_pages(page, CRST_ALLOC_ORDER);
+	list_for_each_entry_safe(ptdesc, next, &gmap->crst_list, pt_list) {
+		ptdesc->_pt_s390_gaddr = 0;
+		pagetable_free(ptdesc);
 	}
 	gmap_radix_tree_free(&gmap->guest_to_host);
 	gmap_radix_tree_free(&gmap->host_to_guest);
 
 	/* Free additional data for a shadow gmap */
 	if (gmap_is_shadow(gmap)) {
-		/* Free all page tables. */
-		list_for_each_entry_safe(page, next, &gmap->pt_list, lru) {
-			page->_pt_s390_gaddr = 0;
-			page_table_free_pgste(page);
+		/* Free all ptdesc tables. */
+		list_for_each_entry_safe(ptdesc, next, &gmap->pt_list, pt_list) {
+			ptdesc->_pt_s390_gaddr = 0;
+			page_table_free_pgste(ptdesc_page(ptdesc));
 		}
 		gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
 		/* Release reference to the parent */
@@ -308,27 +308,27 @@ EXPORT_SYMBOL_GPL(gmap_get_enabled);
 static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
 			    unsigned long init, unsigned long gaddr)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned long *new;
 
 	/* since we dont free the gmap table until gmap_free we can unlock */
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		return -ENOMEM;
-	new = page_to_virt(page);
+	new = ptdesc_to_virt(ptdesc);
 	crst_table_init(new, init);
 	spin_lock(&gmap->guest_table_lock);
 	if (*table & _REGION_ENTRY_INVALID) {
-		list_add(&page->lru, &gmap->crst_list);
+		list_add(&ptdesc->pt_list, &gmap->crst_list);
 		*table = __pa(new) | _REGION_ENTRY_LENGTH |
 			(*table & _REGION_ENTRY_TYPE_MASK);
-		page->_pt_s390_gaddr = gaddr;
-		page = NULL;
+		ptdesc->_pt_s390_gaddr = gaddr;
+		ptdesc = NULL;
 	}
 	spin_unlock(&gmap->guest_table_lock);
-	if (page) {
-		page->_pt_s390_gaddr = 0;
-		__free_pages(page, CRST_ALLOC_ORDER);
+	if (ptdesc) {
+		ptdesc->_pt_s390_gaddr = 0;
+		pagetable_free(ptdesc);
 	}
 	return 0;
 }
@@ -341,15 +341,15 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
  */
 static unsigned long __gmap_segment_gaddr(unsigned long *entry)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned long offset, mask;
 
 	offset = (unsigned long) entry / sizeof(unsigned long);
 	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
 	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
-	page = virt_to_page((void *)((unsigned long) entry & mask));
+	ptdesc = virt_to_ptdesc((void *)((unsigned long) entry & mask));
 
-	return page->_pt_s390_gaddr + offset;
+	return ptdesc->_pt_s390_gaddr + offset;
 }
 
 /**
@@ -1345,6 +1345,7 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
 	unsigned long *ste;
 	phys_addr_t sto, pgt;
 	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
@@ -1358,9 +1359,11 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
 	__gmap_unshadow_pgt(sg, raddr, __va(pgt));
 	/* Free page table */
 	page = phys_to_page(pgt);
-	list_del(&page->lru);
-	page->_pt_s390_gaddr = 0;
-	page_table_free_pgste(page);
+
+	ptdesc = page_ptdesc(page);
+	list_del(&ptdesc->pt_list);
+	ptdesc->_pt_s390_gaddr = 0;
+	page_table_free_pgste(ptdesc_page(ptdesc));
 }
 
 /**
@@ -1374,9 +1377,10 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
 static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
 				unsigned long *sgt)
 {
-	struct page *page;
 	phys_addr_t pgt;
 	int i;
+	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
@@ -1387,9 +1391,11 @@ static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
 		__gmap_unshadow_pgt(sg, raddr, __va(pgt));
 		/* Free page table */
 		page = phys_to_page(pgt);
-		list_del(&page->lru);
-		page->_pt_s390_gaddr = 0;
-		page_table_free_pgste(page);
+
+		ptdesc = page_ptdesc(page);
+		list_del(&ptdesc->pt_list);
+		ptdesc->_pt_s390_gaddr = 0;
+		page_table_free_pgste(ptdesc_page(ptdesc));
 	}
 }
 
@@ -1405,6 +1411,7 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
 	unsigned long r3o, *r3e;
 	phys_addr_t sgt;
 	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
@@ -1418,9 +1425,11 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
 	__gmap_unshadow_sgt(sg, raddr, __va(sgt));
 	/* Free segment table */
 	page = phys_to_page(sgt);
-	list_del(&page->lru);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+
+	ptdesc = page_ptdesc(page);
+	list_del(&ptdesc->pt_list);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 }
 
 /**
@@ -1434,9 +1443,10 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
 static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
 				unsigned long *r3t)
 {
-	struct page *page;
 	phys_addr_t sgt;
 	int i;
+	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
@@ -1447,9 +1457,11 @@ static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
 		__gmap_unshadow_sgt(sg, raddr, __va(sgt));
 		/* Free segment table */
 		page = phys_to_page(sgt);
-		list_del(&page->lru);
-		page->_pt_s390_gaddr = 0;
-		__free_pages(page, CRST_ALLOC_ORDER);
+
+		ptdesc = page_ptdesc(page);
+		list_del(&ptdesc->pt_list);
+		ptdesc->_pt_s390_gaddr = 0;
+		pagetable_free(ptdesc);
 	}
 }
 
@@ -1465,6 +1477,7 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
 	unsigned long r2o, *r2e;
 	phys_addr_t r3t;
 	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
@@ -1478,9 +1491,11 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
 	__gmap_unshadow_r3t(sg, raddr, __va(r3t));
 	/* Free region 3 table */
 	page = phys_to_page(r3t);
-	list_del(&page->lru);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+
+	ptdesc = page_ptdesc(page);
+	list_del(&ptdesc->pt_list);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 }
 
 /**
@@ -1495,8 +1510,9 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
 				unsigned long *r2t)
 {
 	phys_addr_t r3t;
-	struct page *page;
 	int i;
+	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
@@ -1507,9 +1523,11 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
 		__gmap_unshadow_r3t(sg, raddr, __va(r3t));
 		/* Free region 3 table */
 		page = phys_to_page(r3t);
-		list_del(&page->lru);
-		page->_pt_s390_gaddr = 0;
-		__free_pages(page, CRST_ALLOC_ORDER);
+
+		ptdesc = page_ptdesc(page);
+		list_del(&ptdesc->pt_list);
+		ptdesc->_pt_s390_gaddr = 0;
+		pagetable_free(ptdesc);
 	}
 }
 
@@ -1525,6 +1543,7 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
 	unsigned long r1o, *r1e;
 	struct page *page;
 	phys_addr_t r2t;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
@@ -1538,9 +1557,11 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
 	__gmap_unshadow_r2t(sg, raddr, __va(r2t));
 	/* Free region 2 table */
 	page = phys_to_page(r2t);
-	list_del(&page->lru);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+
+	ptdesc = page_ptdesc(page);
+	list_del(&ptdesc->pt_list);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 }
 
 /**
@@ -1558,6 +1579,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
 	struct page *page;
 	phys_addr_t r2t;
 	int i;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	asce = __pa(r1t) | _ASCE_TYPE_REGION1;
@@ -1571,9 +1593,11 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
 		r1t[i] = _REGION1_ENTRY_EMPTY;
 		/* Free region 2 table */
 		page = phys_to_page(r2t);
-		list_del(&page->lru);
-		page->_pt_s390_gaddr = 0;
-		__free_pages(page, CRST_ALLOC_ORDER);
+
+		ptdesc = page_ptdesc(page);
+		list_del(&ptdesc->pt_list);
+		ptdesc->_pt_s390_gaddr = 0;
+		pagetable_free(ptdesc);
 	}
 }
 
@@ -1770,18 +1794,18 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 	unsigned long raddr, origin, offset, len;
 	unsigned long *table;
 	phys_addr_t s_r2t;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	int rc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	/* Allocate a shadow region second table */
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		return -ENOMEM;
-	page->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
+	ptdesc->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
-	s_r2t = page_to_phys(page);
+		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+	s_r2t = page_to_phys(ptdesc_page(ptdesc));
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
 	table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
@@ -1802,7 +1826,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 		 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
 	if (sg->edat_level >= 1)
 		*table |= (r2t & _REGION_ENTRY_PROTECT);
-	list_add(&page->lru, &sg->crst_list);
+	list_add(&ptdesc->pt_list, &sg->crst_list);
 	if (fake) {
 		/* nothing to protect for fake tables */
 		*table &= ~_REGION_ENTRY_INVALID;
@@ -1830,8 +1854,8 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
@@ -1855,18 +1879,18 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
 	unsigned long raddr, origin, offset, len;
 	unsigned long *table;
 	phys_addr_t s_r3t;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	int rc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	/* Allocate a shadow region second table */
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		return -ENOMEM;
-	page->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
+	ptdesc->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
-	s_r3t = page_to_phys(page);
+		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+	s_r3t = page_to_phys(ptdesc_page(ptdesc));
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
 	table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
@@ -1887,7 +1911,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
 		 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
 	if (sg->edat_level >= 1)
 		*table |= (r3t & _REGION_ENTRY_PROTECT);
-	list_add(&page->lru, &sg->crst_list);
+	list_add(&ptdesc->pt_list, &sg->crst_list);
 	if (fake) {
 		/* nothing to protect for fake tables */
 		*table &= ~_REGION_ENTRY_INVALID;
@@ -1915,8 +1939,8 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
@@ -1940,18 +1964,18 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 	unsigned long raddr, origin, offset, len;
 	unsigned long *table;
 	phys_addr_t s_sgt;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	int rc;
 
 	BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
 	/* Allocate a shadow segment table */
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		return -ENOMEM;
-	page->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
+	ptdesc->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
 	if (fake)
-		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
-	s_sgt = page_to_phys(page);
+		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+	s_sgt = page_to_phys(ptdesc_page(ptdesc));
 	/* Install shadow region second table */
 	spin_lock(&sg->guest_table_lock);
 	table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
@@ -1972,7 +1996,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 		 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
 	if (sg->edat_level >= 1)
 		*table |= sgt & _REGION_ENTRY_PROTECT;
-	list_add(&page->lru, &sg->crst_list);
+	list_add(&ptdesc->pt_list, &sg->crst_list);
 	if (fake) {
 		/* nothing to protect for fake tables */
 		*table &= ~_REGION_ENTRY_INVALID;
@@ -2000,8 +2024,8 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
-	page->_pt_s390_gaddr = 0;
-	__free_pages(page, CRST_ALLOC_ORDER);
+	ptdesc->_pt_s390_gaddr = 0;
+	pagetable_free(ptdesc);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
@@ -2024,8 +2048,9 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
 			   int *fake)
 {
 	unsigned long *table;
-	struct page *page;
 	int rc;
+	struct page *page;
+	struct ptdesc *ptdesc;
 
 	BUG_ON(!gmap_is_shadow(sg));
 	spin_lock(&sg->guest_table_lock);
@@ -2033,9 +2058,10 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
 	if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
 		/* Shadow page tables are full pages (pte+pgste) */
 		page = pfn_to_page(*table >> PAGE_SHIFT);
-		*pgt = page->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
+		ptdesc = page_ptdesc(page);
+		*pgt = ptdesc->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
 		*dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
-		*fake = !!(page->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
+		*fake = !!(ptdesc->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
 		rc = 0;
 	} else  {
 		rc = -EAGAIN;
@@ -2064,19 +2090,19 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 {
 	unsigned long raddr, origin;
 	unsigned long *table;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	phys_addr_t s_pgt;
 	int rc;
 
 	BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
 	/* Allocate a shadow page table */
-	page = page_table_alloc_pgste(sg->mm);
-	if (!page)
+	ptdesc = page_ptdesc(page_table_alloc_pgste(sg->mm));
+	if (!ptdesc)
 		return -ENOMEM;
-	page->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
+	ptdesc->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
 	if (fake)
-		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
-	s_pgt = page_to_phys(page);
+		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+	s_pgt = page_to_phys(ptdesc_page(ptdesc));
 	/* Install shadow page table */
 	spin_lock(&sg->guest_table_lock);
 	table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
@@ -2094,7 +2120,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 	/* mark as invalid as long as the parent table is not protected */
 	*table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
 		 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
-	list_add(&page->lru, &sg->pt_list);
+	list_add(&ptdesc->pt_list, &sg->pt_list);
 	if (fake) {
 		/* nothing to protect for fake tables */
 		*table &= ~_SEGMENT_ENTRY_INVALID;
@@ -2120,8 +2146,8 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 	return rc;
 out_free:
 	spin_unlock(&sg->guest_table_lock);
-	page->_pt_s390_gaddr = 0;
-	page_table_free_pgste(page);
+	ptdesc->_pt_s390_gaddr = 0;
+	page_table_free_pgste(ptdesc_page(ptdesc));
 	return rc;
 
 }
@@ -2814,11 +2840,11 @@ EXPORT_SYMBOL_GPL(__s390_uv_destroy_range);
  */
 void s390_unlist_old_asce(struct gmap *gmap)
 {
-	struct page *old;
+	struct ptdesc *old;
 
-	old = virt_to_page(gmap->table);
+	old = virt_to_ptdesc(gmap->table);
 	spin_lock(&gmap->guest_table_lock);
-	list_del(&old->lru);
+	list_del(&old->pt_list);
 	/*
 	 * Sometimes the topmost page might need to be "removed" multiple
 	 * times, for example if the VM is rebooted into secure mode several
@@ -2833,7 +2859,7 @@ void s390_unlist_old_asce(struct gmap *gmap)
 	 * pointers, so list_del can work (and do nothing) without
 	 * dereferencing stale or invalid pointers.
 	 */
-	INIT_LIST_HEAD(&old->lru);
+	INIT_LIST_HEAD(&old->pt_list);
 	spin_unlock(&gmap->guest_table_lock);
 }
 EXPORT_SYMBOL_GPL(s390_unlist_old_asce);
@@ -2854,7 +2880,7 @@ EXPORT_SYMBOL_GPL(s390_unlist_old_asce);
 int s390_replace_asce(struct gmap *gmap)
 {
 	unsigned long asce;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	void *table;
 
 	s390_unlist_old_asce(gmap);
@@ -2863,10 +2889,10 @@ int s390_replace_asce(struct gmap *gmap)
 	if ((gmap->asce & _ASCE_TYPE_MASK) == _ASCE_TYPE_SEGMENT)
 		return -EINVAL;
 
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+	if (!ptdesc)
 		return -ENOMEM;
-	table = page_to_virt(page);
+	table = ptdesc_to_virt(ptdesc);
 	memcpy(table, gmap->table, 1UL << (CRST_ALLOC_ORDER + PAGE_SHIFT));
 
 	/*
@@ -2875,7 +2901,7 @@ int s390_replace_asce(struct gmap *gmap)
 	 * it will be freed when the VM is torn down.
 	 */
 	spin_lock(&gmap->guest_table_lock);
-	list_add(&page->lru, &gmap->crst_list);
+	list_add(&ptdesc->pt_list, &gmap->crst_list);
 	spin_unlock(&gmap->guest_table_lock);
 
 	/* Set new table origin while preserving existing ASCE control bits */
-- 
2.40.1

Re: [PATCH v4 16/34] s390: Convert various gmap functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:05PM -0700, Vishal Moola (Oracle) wrote:
> In order to split struct ptdesc from struct page, convert various
> functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

With folding

	ptdesc->_pt_s390_gaddr = 0;

into pagetable_free()

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>


> ---
>  arch/s390/mm/gmap.c | 230 ++++++++++++++++++++++++--------------------
>  1 file changed, 128 insertions(+), 102 deletions(-)
> 
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 81c683426b49..010e87df7299 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -34,7 +34,7 @@
>  static struct gmap *gmap_alloc(unsigned long limit)
>  {
>  	struct gmap *gmap;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	unsigned long *table;
>  	unsigned long etype, atype;
>  
> @@ -67,12 +67,12 @@ static struct gmap *gmap_alloc(unsigned long limit)
>  	spin_lock_init(&gmap->guest_table_lock);
>  	spin_lock_init(&gmap->shadow_lock);
>  	refcount_set(&gmap->ref_count, 1);
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		goto out_free;
> -	page->_pt_s390_gaddr = 0;
> -	list_add(&page->lru, &gmap->crst_list);
> -	table = page_to_virt(page);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	list_add(&ptdesc->pt_list, &gmap->crst_list);
> +	table = ptdesc_to_virt(ptdesc);
>  	crst_table_init(table, etype);
>  	gmap->table = table;
>  	gmap->asce = atype | _ASCE_TABLE_LENGTH |
> @@ -181,25 +181,25 @@ static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
>   */
>  static void gmap_free(struct gmap *gmap)
>  {
> -	struct page *page, *next;
> +	struct ptdesc *ptdesc, *next;
>  
>  	/* Flush tlb of all gmaps (if not already done for shadows) */
>  	if (!(gmap_is_shadow(gmap) && gmap->removed))
>  		gmap_flush_tlb(gmap);
>  	/* Free all segment & region tables. */
> -	list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
> -		page->_pt_s390_gaddr = 0;
> -		__free_pages(page, CRST_ALLOC_ORDER);
> +	list_for_each_entry_safe(ptdesc, next, &gmap->crst_list, pt_list) {
> +		ptdesc->_pt_s390_gaddr = 0;
> +		pagetable_free(ptdesc);
>  	}
>  	gmap_radix_tree_free(&gmap->guest_to_host);
>  	gmap_radix_tree_free(&gmap->host_to_guest);
>  
>  	/* Free additional data for a shadow gmap */
>  	if (gmap_is_shadow(gmap)) {
> -		/* Free all page tables. */
> -		list_for_each_entry_safe(page, next, &gmap->pt_list, lru) {
> -			page->_pt_s390_gaddr = 0;
> -			page_table_free_pgste(page);
> +		/* Free all ptdesc tables. */
> +		list_for_each_entry_safe(ptdesc, next, &gmap->pt_list, pt_list) {
> +			ptdesc->_pt_s390_gaddr = 0;
> +			page_table_free_pgste(ptdesc_page(ptdesc));
>  		}
>  		gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
>  		/* Release reference to the parent */
> @@ -308,27 +308,27 @@ EXPORT_SYMBOL_GPL(gmap_get_enabled);
>  static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>  			    unsigned long init, unsigned long gaddr)
>  {
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	unsigned long *new;
>  
>  	/* since we dont free the gmap table until gmap_free we can unlock */
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	new = page_to_virt(page);
> +	new = ptdesc_to_virt(ptdesc);
>  	crst_table_init(new, init);
>  	spin_lock(&gmap->guest_table_lock);
>  	if (*table & _REGION_ENTRY_INVALID) {
> -		list_add(&page->lru, &gmap->crst_list);
> +		list_add(&ptdesc->pt_list, &gmap->crst_list);
>  		*table = __pa(new) | _REGION_ENTRY_LENGTH |
>  			(*table & _REGION_ENTRY_TYPE_MASK);
> -		page->_pt_s390_gaddr = gaddr;
> -		page = NULL;
> +		ptdesc->_pt_s390_gaddr = gaddr;
> +		ptdesc = NULL;
>  	}
>  	spin_unlock(&gmap->guest_table_lock);
> -	if (page) {
> -		page->_pt_s390_gaddr = 0;
> -		__free_pages(page, CRST_ALLOC_ORDER);
> +	if (ptdesc) {
> +		ptdesc->_pt_s390_gaddr = 0;
> +		pagetable_free(ptdesc);
>  	}
>  	return 0;
>  }
> @@ -341,15 +341,15 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>   */
>  static unsigned long __gmap_segment_gaddr(unsigned long *entry)
>  {
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	unsigned long offset, mask;
>  
>  	offset = (unsigned long) entry / sizeof(unsigned long);
>  	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
>  	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> -	page = virt_to_page((void *)((unsigned long) entry & mask));
> +	ptdesc = virt_to_ptdesc((void *)((unsigned long) entry & mask));
>  
> -	return page->_pt_s390_gaddr + offset;
> +	return ptdesc->_pt_s390_gaddr + offset;
>  }
>  
>  /**
> @@ -1345,6 +1345,7 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
>  	unsigned long *ste;
>  	phys_addr_t sto, pgt;
>  	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
> @@ -1358,9 +1359,11 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
>  	__gmap_unshadow_pgt(sg, raddr, __va(pgt));
>  	/* Free page table */
>  	page = phys_to_page(pgt);
> -	list_del(&page->lru);
> -	page->_pt_s390_gaddr = 0;
> -	page_table_free_pgste(page);
> +
> +	ptdesc = page_ptdesc(page);
> +	list_del(&ptdesc->pt_list);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	page_table_free_pgste(ptdesc_page(ptdesc));
>  }
>  
>  /**
> @@ -1374,9 +1377,10 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
>  static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
>  				unsigned long *sgt)
>  {
> -	struct page *page;
>  	phys_addr_t pgt;
>  	int i;
> +	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
> @@ -1387,9 +1391,11 @@ static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
>  		__gmap_unshadow_pgt(sg, raddr, __va(pgt));
>  		/* Free page table */
>  		page = phys_to_page(pgt);
> -		list_del(&page->lru);
> -		page->_pt_s390_gaddr = 0;
> -		page_table_free_pgste(page);
> +
> +		ptdesc = page_ptdesc(page);
> +		list_del(&ptdesc->pt_list);
> +		ptdesc->_pt_s390_gaddr = 0;
> +		page_table_free_pgste(ptdesc_page(ptdesc));
>  	}
>  }
>  
> @@ -1405,6 +1411,7 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
>  	unsigned long r3o, *r3e;
>  	phys_addr_t sgt;
>  	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
> @@ -1418,9 +1425,11 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
>  	__gmap_unshadow_sgt(sg, raddr, __va(sgt));
>  	/* Free segment table */
>  	page = phys_to_page(sgt);
> -	list_del(&page->lru);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +
> +	ptdesc = page_ptdesc(page);
> +	list_del(&ptdesc->pt_list);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  }
>  
>  /**
> @@ -1434,9 +1443,10 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
>  static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
>  				unsigned long *r3t)
>  {
> -	struct page *page;
>  	phys_addr_t sgt;
>  	int i;
> +	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
> @@ -1447,9 +1457,11 @@ static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
>  		__gmap_unshadow_sgt(sg, raddr, __va(sgt));
>  		/* Free segment table */
>  		page = phys_to_page(sgt);
> -		list_del(&page->lru);
> -		page->_pt_s390_gaddr = 0;
> -		__free_pages(page, CRST_ALLOC_ORDER);
> +
> +		ptdesc = page_ptdesc(page);
> +		list_del(&ptdesc->pt_list);
> +		ptdesc->_pt_s390_gaddr = 0;
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> @@ -1465,6 +1477,7 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
>  	unsigned long r2o, *r2e;
>  	phys_addr_t r3t;
>  	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
> @@ -1478,9 +1491,11 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
>  	__gmap_unshadow_r3t(sg, raddr, __va(r3t));
>  	/* Free region 3 table */
>  	page = phys_to_page(r3t);
> -	list_del(&page->lru);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +
> +	ptdesc = page_ptdesc(page);
> +	list_del(&ptdesc->pt_list);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  }
>  
>  /**
> @@ -1495,8 +1510,9 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
>  				unsigned long *r2t)
>  {
>  	phys_addr_t r3t;
> -	struct page *page;
>  	int i;
> +	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
> @@ -1507,9 +1523,11 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
>  		__gmap_unshadow_r3t(sg, raddr, __va(r3t));
>  		/* Free region 3 table */
>  		page = phys_to_page(r3t);
> -		list_del(&page->lru);
> -		page->_pt_s390_gaddr = 0;
> -		__free_pages(page, CRST_ALLOC_ORDER);
> +
> +		ptdesc = page_ptdesc(page);
> +		list_del(&ptdesc->pt_list);
> +		ptdesc->_pt_s390_gaddr = 0;
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> @@ -1525,6 +1543,7 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
>  	unsigned long r1o, *r1e;
>  	struct page *page;
>  	phys_addr_t r2t;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
> @@ -1538,9 +1557,11 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
>  	__gmap_unshadow_r2t(sg, raddr, __va(r2t));
>  	/* Free region 2 table */
>  	page = phys_to_page(r2t);
> -	list_del(&page->lru);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +
> +	ptdesc = page_ptdesc(page);
> +	list_del(&ptdesc->pt_list);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  }
>  
>  /**
> @@ -1558,6 +1579,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
>  	struct page *page;
>  	phys_addr_t r2t;
>  	int i;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	asce = __pa(r1t) | _ASCE_TYPE_REGION1;
> @@ -1571,9 +1593,11 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
>  		r1t[i] = _REGION1_ENTRY_EMPTY;
>  		/* Free region 2 table */
>  		page = phys_to_page(r2t);
> -		list_del(&page->lru);
> -		page->_pt_s390_gaddr = 0;
> -		__free_pages(page, CRST_ALLOC_ORDER);
> +
> +		ptdesc = page_ptdesc(page);
> +		list_del(&ptdesc->pt_list);
> +		ptdesc->_pt_s390_gaddr = 0;
> +		pagetable_free(ptdesc);
>  	}
>  }
>  
> @@ -1770,18 +1794,18 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
>  	unsigned long raddr, origin, offset, len;
>  	unsigned long *table;
>  	phys_addr_t s_r2t;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	int rc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	/* Allocate a shadow region second table */
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	page->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
> +	ptdesc->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> -	s_r2t = page_to_phys(page);
> +		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> +	s_r2t = page_to_phys(ptdesc_page(ptdesc));
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
>  	table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
> @@ -1802,7 +1826,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
>  		 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
>  	if (sg->edat_level >= 1)
>  		*table |= (r2t & _REGION_ENTRY_PROTECT);
> -	list_add(&page->lru, &sg->crst_list);
> +	list_add(&ptdesc->pt_list, &sg->crst_list);
>  	if (fake) {
>  		/* nothing to protect for fake tables */
>  		*table &= ~_REGION_ENTRY_INVALID;
> @@ -1830,8 +1854,8 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  	return rc;
>  }
>  EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
> @@ -1855,18 +1879,18 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
>  	unsigned long raddr, origin, offset, len;
>  	unsigned long *table;
>  	phys_addr_t s_r3t;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	int rc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	/* Allocate a shadow region second table */
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	page->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
> +	ptdesc->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> -	s_r3t = page_to_phys(page);
> +		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> +	s_r3t = page_to_phys(ptdesc_page(ptdesc));
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
>  	table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
> @@ -1887,7 +1911,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
>  		 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
>  	if (sg->edat_level >= 1)
>  		*table |= (r3t & _REGION_ENTRY_PROTECT);
> -	list_add(&page->lru, &sg->crst_list);
> +	list_add(&ptdesc->pt_list, &sg->crst_list);
>  	if (fake) {
>  		/* nothing to protect for fake tables */
>  		*table &= ~_REGION_ENTRY_INVALID;
> @@ -1915,8 +1939,8 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  	return rc;
>  }
>  EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
> @@ -1940,18 +1964,18 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
>  	unsigned long raddr, origin, offset, len;
>  	unsigned long *table;
>  	phys_addr_t s_sgt;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	int rc;
>  
>  	BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
>  	/* Allocate a shadow segment table */
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	page->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
> +	ptdesc->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
>  	if (fake)
> -		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> -	s_sgt = page_to_phys(page);
> +		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> +	s_sgt = page_to_phys(ptdesc_page(ptdesc));
>  	/* Install shadow region second table */
>  	spin_lock(&sg->guest_table_lock);
>  	table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
> @@ -1972,7 +1996,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
>  		 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
>  	if (sg->edat_level >= 1)
>  		*table |= sgt & _REGION_ENTRY_PROTECT;
> -	list_add(&page->lru, &sg->crst_list);
> +	list_add(&ptdesc->pt_list, &sg->crst_list);
>  	if (fake) {
>  		/* nothing to protect for fake tables */
>  		*table &= ~_REGION_ENTRY_INVALID;
> @@ -2000,8 +2024,8 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> -	page->_pt_s390_gaddr = 0;
> -	__free_pages(page, CRST_ALLOC_ORDER);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	pagetable_free(ptdesc);
>  	return rc;
>  }
>  EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
> @@ -2024,8 +2048,9 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
>  			   int *fake)
>  {
>  	unsigned long *table;
> -	struct page *page;
>  	int rc;
> +	struct page *page;
> +	struct ptdesc *ptdesc;
>  
>  	BUG_ON(!gmap_is_shadow(sg));
>  	spin_lock(&sg->guest_table_lock);
> @@ -2033,9 +2058,10 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
>  	if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
>  		/* Shadow page tables are full pages (pte+pgste) */
>  		page = pfn_to_page(*table >> PAGE_SHIFT);
> -		*pgt = page->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
> +		ptdesc = page_ptdesc(page);
> +		*pgt = ptdesc->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
>  		*dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
> -		*fake = !!(page->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
> +		*fake = !!(ptdesc->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
>  		rc = 0;
>  	} else  {
>  		rc = -EAGAIN;
> @@ -2064,19 +2090,19 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
>  {
>  	unsigned long raddr, origin;
>  	unsigned long *table;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	phys_addr_t s_pgt;
>  	int rc;
>  
>  	BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
>  	/* Allocate a shadow page table */
> -	page = page_table_alloc_pgste(sg->mm);
> -	if (!page)
> +	ptdesc = page_ptdesc(page_table_alloc_pgste(sg->mm));
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	page->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
> +	ptdesc->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
>  	if (fake)
> -		page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> -	s_pgt = page_to_phys(page);
> +		ptdesc->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
> +	s_pgt = page_to_phys(ptdesc_page(ptdesc));
>  	/* Install shadow page table */
>  	spin_lock(&sg->guest_table_lock);
>  	table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
> @@ -2094,7 +2120,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
>  	/* mark as invalid as long as the parent table is not protected */
>  	*table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
>  		 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
> -	list_add(&page->lru, &sg->pt_list);
> +	list_add(&ptdesc->pt_list, &sg->pt_list);
>  	if (fake) {
>  		/* nothing to protect for fake tables */
>  		*table &= ~_SEGMENT_ENTRY_INVALID;
> @@ -2120,8 +2146,8 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
>  	return rc;
>  out_free:
>  	spin_unlock(&sg->guest_table_lock);
> -	page->_pt_s390_gaddr = 0;
> -	page_table_free_pgste(page);
> +	ptdesc->_pt_s390_gaddr = 0;
> +	page_table_free_pgste(ptdesc_page(ptdesc));
>  	return rc;
>  
>  }
> @@ -2814,11 +2840,11 @@ EXPORT_SYMBOL_GPL(__s390_uv_destroy_range);
>   */
>  void s390_unlist_old_asce(struct gmap *gmap)
>  {
> -	struct page *old;
> +	struct ptdesc *old;
>  
> -	old = virt_to_page(gmap->table);
> +	old = virt_to_ptdesc(gmap->table);
>  	spin_lock(&gmap->guest_table_lock);
> -	list_del(&old->lru);
> +	list_del(&old->pt_list);
>  	/*
>  	 * Sometimes the topmost page might need to be "removed" multiple
>  	 * times, for example if the VM is rebooted into secure mode several
> @@ -2833,7 +2859,7 @@ void s390_unlist_old_asce(struct gmap *gmap)
>  	 * pointers, so list_del can work (and do nothing) without
>  	 * dereferencing stale or invalid pointers.
>  	 */
> -	INIT_LIST_HEAD(&old->lru);
> +	INIT_LIST_HEAD(&old->pt_list);
>  	spin_unlock(&gmap->guest_table_lock);
>  }
>  EXPORT_SYMBOL_GPL(s390_unlist_old_asce);
> @@ -2854,7 +2880,7 @@ EXPORT_SYMBOL_GPL(s390_unlist_old_asce);
>  int s390_replace_asce(struct gmap *gmap)
>  {
>  	unsigned long asce;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	void *table;
>  
>  	s390_unlist_old_asce(gmap);
> @@ -2863,10 +2889,10 @@ int s390_replace_asce(struct gmap *gmap)
>  	if ((gmap->asce & _ASCE_TYPE_MASK) == _ASCE_TYPE_SEGMENT)
>  		return -EINVAL;
>  
> -	page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
>  		return -ENOMEM;
> -	table = page_to_virt(page);
> +	table = ptdesc_to_virt(ptdesc);
>  	memcpy(table, gmap->table, 1UL << (CRST_ALLOC_ORDER + PAGE_SHIFT));
>  
>  	/*
> @@ -2875,7 +2901,7 @@ int s390_replace_asce(struct gmap *gmap)
>  	 * it will be freed when the VM is torn down.
>  	 */
>  	spin_lock(&gmap->guest_table_lock);
> -	list_add(&page->lru, &gmap->crst_list);
> +	list_add(&ptdesc->pt_list, &gmap->crst_list);
>  	spin_unlock(&gmap->guest_table_lock);
>  
>  	/* Set new table origin while preserving existing ASCE control bits */
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 17/34] s390: Convert various pgalloc functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/s390/include/asm/pgalloc.h |   4 +-
 arch/s390/include/asm/tlb.h     |   4 +-
 arch/s390/mm/pgalloc.c          | 108 ++++++++++++++++----------------
 3 files changed, 59 insertions(+), 57 deletions(-)

diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 17eb618f1348..00ad9b88fda9 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -86,7 +86,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
 	if (!table)
 		return NULL;
 	crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
-	if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
+	if (!pagetable_pmd_ctor(virt_to_ptdesc(table))) {
 		crst_table_free(mm, table);
 		return NULL;
 	}
@@ -97,7 +97,7 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
 	if (mm_pmd_folded(mm))
 		return;
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
 	crst_table_free(mm, (unsigned long *) pmd);
 }
 
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index b91f4a9b044c..383b1f91442c 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -89,12 +89,12 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
 {
 	if (mm_pmd_folded(tlb->mm))
 		return;
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
 	__tlb_adjust_range(tlb, address, PAGE_SIZE);
 	tlb->mm->context.flush_mm = 1;
 	tlb->freed_tables = 1;
 	tlb->cleared_puds = 1;
-	tlb_remove_table(tlb, pmd);
+	tlb_remove_ptdesc(tlb, pmd);
 }
 
 /*
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 6b99932abc66..eeb7c95b98cf 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -43,17 +43,17 @@ __initcall(page_table_register_sysctl);
 
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {
-	struct page *page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
 
-	if (!page)
+	if (!ptdesc)
 		return NULL;
-	arch_set_page_dat(page, CRST_ALLOC_ORDER);
-	return (unsigned long *) page_to_virt(page);
+	arch_set_page_dat(ptdesc_page(ptdesc), CRST_ALLOC_ORDER);
+	return (unsigned long *) ptdesc_to_virt(ptdesc);
 }
 
 void crst_table_free(struct mm_struct *mm, unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 static void __crst_table_upgrade(void *arg)
@@ -140,21 +140,21 @@ static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
 
 struct page *page_table_alloc_pgste(struct mm_struct *mm)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	u64 *table;
 
-	page = alloc_page(GFP_KERNEL);
-	if (page) {
-		table = (u64 *)page_to_virt(page);
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (ptdesc) {
+		table = (u64 *)ptdesc_to_virt(ptdesc);
 		memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	}
-	return page;
+	return ptdesc_page(ptdesc);
 }
 
 void page_table_free_pgste(struct page *page)
 {
-	__free_page(page);
+	pagetable_free(page_ptdesc(page));
 }
 
 #endif /* CONFIG_PGSTE */
@@ -230,7 +230,7 @@ void page_table_free_pgste(struct page *page)
 unsigned long *page_table_alloc(struct mm_struct *mm)
 {
 	unsigned long *table;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned int mask, bit;
 
 	/* Try to get a fragment of a 4K page as a 2K page table */
@@ -238,9 +238,9 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 		table = NULL;
 		spin_lock_bh(&mm->context.lock);
 		if (!list_empty(&mm->context.pgtable_list)) {
-			page = list_first_entry(&mm->context.pgtable_list,
-						struct page, lru);
-			mask = atomic_read(&page->pt_frag_refcount);
+			ptdesc = list_first_entry(&mm->context.pgtable_list,
+						struct ptdesc, pt_list);
+			mask = atomic_read(&ptdesc->pt_frag_refcount);
 			/*
 			 * The pending removal bits must also be checked.
 			 * Failure to do so might lead to an impossible
@@ -253,13 +253,13 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			 */
 			mask = (mask | (mask >> 4)) & 0x03U;
 			if (mask != 0x03U) {
-				table = (unsigned long *) page_to_virt(page);
+				table = (unsigned long *) ptdesc_to_virt(ptdesc);
 				bit = mask & 1;		/* =1 -> second 2K */
 				if (bit)
 					table += PTRS_PER_PTE;
-				atomic_xor_bits(&page->pt_frag_refcount,
+				atomic_xor_bits(&ptdesc->pt_frag_refcount,
 							0x01U << bit);
-				list_del(&page->lru);
+				list_del(&ptdesc->pt_list);
 			}
 		}
 		spin_unlock_bh(&mm->context.lock);
@@ -267,27 +267,27 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			return table;
 	}
 	/* Allocate a fresh page */
-	page = alloc_page(GFP_KERNEL);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
-	arch_set_page_dat(page, 0);
+	arch_set_page_dat(ptdesc_page(ptdesc), 0);
 	/* Initialize page table */
-	table = (unsigned long *) page_to_virt(page);
+	table = (unsigned long *) ptdesc_to_virt(ptdesc);
 	if (mm_alloc_pgste(mm)) {
 		/* Return 4K page table with PGSTEs */
-		atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	} else {
 		/* Return the first 2K fragment of the page */
-		atomic_xor_bits(&page->pt_frag_refcount, 0x01U);
+		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x01U);
 		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
 		spin_lock_bh(&mm->context.lock);
-		list_add(&page->lru, &mm->context.pgtable_list);
+		list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
 		spin_unlock_bh(&mm->context.lock);
 	}
 	return table;
@@ -309,9 +309,8 @@ static void page_table_release_check(struct page *page, void *table,
 void page_table_free(struct mm_struct *mm, unsigned long *table)
 {
 	unsigned int mask, bit, half;
-	struct page *page;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
-	page = virt_to_page(table);
 	if (!mm_alloc_pgste(mm)) {
 		/* Free 2K page table fragment of a 4K page */
 		bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
@@ -321,39 +320,38 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
 		 * will happen outside of the critical section from this
 		 * function or from __tlb_remove_table()
 		 */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
 		if (mask & 0x03U)
-			list_add(&page->lru, &mm->context.pgtable_list);
+			list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
 		else
-			list_del(&page->lru);
+			list_del(&ptdesc->pt_list);
 		spin_unlock_bh(&mm->context.lock);
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x10U << bit);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x10U << bit);
 		if (mask != 0x00U)
 			return;
 		half = 0x01U << bit;
 	} else {
 		half = 0x03U;
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 			 unsigned long vmaddr)
 {
 	struct mm_struct *mm;
-	struct page *page;
 	unsigned int bit, mask;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	mm = tlb->mm;
-	page = virt_to_page(table);
 	if (mm_alloc_pgste(mm)) {
 		gmap_unlink(mm, table, vmaddr);
 		table = (unsigned long *) ((unsigned long)table | 0x03U);
-		tlb_remove_table(tlb, table);
+		tlb_remove_ptdesc(tlb, table);
 		return;
 	}
 	bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
@@ -363,11 +361,11 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 	 * outside of the critical section from __tlb_remove_table() or from
 	 * page_table_free()
 	 */
-	mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
+	mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
 	if (mask & 0x03U)
-		list_add_tail(&page->lru, &mm->context.pgtable_list);
+		list_add_tail(&ptdesc->pt_list, &mm->context.pgtable_list);
 	else
-		list_del(&page->lru);
+		list_del(&ptdesc->pt_list);
 	spin_unlock_bh(&mm->context.lock);
 	table = (unsigned long *) ((unsigned long) table | (0x01U << bit));
 	tlb_remove_table(tlb, table);
@@ -377,7 +375,7 @@ void __tlb_remove_table(void *_table)
 {
 	unsigned int mask = (unsigned long) _table & 0x03U, half = mask;
 	void *table = (void *)((unsigned long) _table ^ mask);
-	struct page *page = virt_to_page(table);
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	switch (half) {
 	case 0x00U:	/* pmd, pud, or p4d */
@@ -385,18 +383,18 @@ void __tlb_remove_table(void *_table)
 		return;
 	case 0x01U:	/* lower 2K of a 4K page table */
 	case 0x02U:	/* higher 2K of a 4K page table */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, mask << 4);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, mask << 4);
 		if (mask != 0x00U)
 			return;
 		break;
 	case 0x03U:	/* 4K page table with pgstes */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 		break;
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 /*
@@ -424,16 +422,20 @@ static void base_pgt_free(unsigned long *table)
 static unsigned long *base_crst_alloc(unsigned long val)
 {
 	unsigned long *table;
+	struct ptdesc *ptdesc;
 
-	table =	(unsigned long *)__get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
-	if (table)
-		crst_table_init(table, val);
+	ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
+	if (!ptdesc)
+		return NULL;
+	table = ptdesc_address(ptdesc);
+
+	crst_table_init(table, val);
 	return table;
 }
 
 static void base_crst_free(unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 #define BASE_ADDR_END_FUNC(NAME, SIZE)					\
-- 
2.40.1

Re: [PATCH v4 17/34] s390: Convert various pgalloc functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:06PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/s390/include/asm/pgalloc.h |   4 +-
>  arch/s390/include/asm/tlb.h     |   4 +-
>  arch/s390/mm/pgalloc.c          | 108 ++++++++++++++++----------------
>  3 files changed, 59 insertions(+), 57 deletions(-)
> 
> diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
> index 17eb618f1348..00ad9b88fda9 100644
> --- a/arch/s390/include/asm/pgalloc.h
> +++ b/arch/s390/include/asm/pgalloc.h
> @@ -86,7 +86,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
>  	if (!table)
>  		return NULL;
>  	crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
> -	if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
> +	if (!pagetable_pmd_ctor(virt_to_ptdesc(table))) {
>  		crst_table_free(mm, table);
>  		return NULL;
>  	}
> @@ -97,7 +97,7 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
>  {
>  	if (mm_pmd_folded(mm))
>  		return;
> -	pgtable_pmd_page_dtor(virt_to_page(pmd));
> +	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
>  	crst_table_free(mm, (unsigned long *) pmd);
>  }
>  
> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
> index b91f4a9b044c..383b1f91442c 100644
> --- a/arch/s390/include/asm/tlb.h
> +++ b/arch/s390/include/asm/tlb.h
> @@ -89,12 +89,12 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
>  {
>  	if (mm_pmd_folded(tlb->mm))
>  		return;
> -	pgtable_pmd_page_dtor(virt_to_page(pmd));
> +	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
>  	__tlb_adjust_range(tlb, address, PAGE_SIZE);
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
>  	tlb->cleared_puds = 1;
> -	tlb_remove_table(tlb, pmd);
> +	tlb_remove_ptdesc(tlb, pmd);
>  }
>  
>  /*
> diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
> index 6b99932abc66..eeb7c95b98cf 100644
> --- a/arch/s390/mm/pgalloc.c
> +++ b/arch/s390/mm/pgalloc.c
> @@ -43,17 +43,17 @@ __initcall(page_table_register_sysctl);
>  
>  unsigned long *crst_table_alloc(struct mm_struct *mm)
>  {
> -	struct page *page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
>  
> -	if (!page)
> +	if (!ptdesc)
>  		return NULL;
> -	arch_set_page_dat(page, CRST_ALLOC_ORDER);
> -	return (unsigned long *) page_to_virt(page);
> +	arch_set_page_dat(ptdesc_page(ptdesc), CRST_ALLOC_ORDER);
> +	return (unsigned long *) ptdesc_to_virt(ptdesc);
>  }
>  
>  void crst_table_free(struct mm_struct *mm, unsigned long *table)
>  {
> -	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
> +	pagetable_free(virt_to_ptdesc(table));
>  }
>  
>  static void __crst_table_upgrade(void *arg)
> @@ -140,21 +140,21 @@ static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
>  
>  struct page *page_table_alloc_pgste(struct mm_struct *mm)
>  {
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	u64 *table;
>  
> -	page = alloc_page(GFP_KERNEL);
> -	if (page) {
> -		table = (u64 *)page_to_virt(page);
> +	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
> +	if (ptdesc) {
> +		table = (u64 *)ptdesc_to_virt(ptdesc);
>  		memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
>  		memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
>  	}
> -	return page;
> +	return ptdesc_page(ptdesc);
>  }
>  
>  void page_table_free_pgste(struct page *page)
>  {
> -	__free_page(page);
> +	pagetable_free(page_ptdesc(page));
>  }
>  
>  #endif /* CONFIG_PGSTE */
> @@ -230,7 +230,7 @@ void page_table_free_pgste(struct page *page)
>  unsigned long *page_table_alloc(struct mm_struct *mm)
>  {
>  	unsigned long *table;
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	unsigned int mask, bit;
>  
>  	/* Try to get a fragment of a 4K page as a 2K page table */
> @@ -238,9 +238,9 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  		table = NULL;
>  		spin_lock_bh(&mm->context.lock);
>  		if (!list_empty(&mm->context.pgtable_list)) {
> -			page = list_first_entry(&mm->context.pgtable_list,
> -						struct page, lru);
> -			mask = atomic_read(&page->pt_frag_refcount);
> +			ptdesc = list_first_entry(&mm->context.pgtable_list,
> +						struct ptdesc, pt_list);
> +			mask = atomic_read(&ptdesc->pt_frag_refcount);
>  			/*
>  			 * The pending removal bits must also be checked.
>  			 * Failure to do so might lead to an impossible
> @@ -253,13 +253,13 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  			 */
>  			mask = (mask | (mask >> 4)) & 0x03U;
>  			if (mask != 0x03U) {
> -				table = (unsigned long *) page_to_virt(page);
> +				table = (unsigned long *) ptdesc_to_virt(ptdesc);
>  				bit = mask & 1;		/* =1 -> second 2K */
>  				if (bit)
>  					table += PTRS_PER_PTE;
> -				atomic_xor_bits(&page->pt_frag_refcount,
> +				atomic_xor_bits(&ptdesc->pt_frag_refcount,
>  							0x01U << bit);
> -				list_del(&page->lru);
> +				list_del(&ptdesc->pt_list);
>  			}
>  		}
>  		spin_unlock_bh(&mm->context.lock);
> @@ -267,27 +267,27 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
>  			return table;
>  	}
>  	/* Allocate a fresh page */
> -	page = alloc_page(GFP_KERNEL);
> -	if (!page)
> +	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pte_page_ctor(page)) {
> -		__free_page(page);
> +	if (!pagetable_pte_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
> -	arch_set_page_dat(page, 0);
> +	arch_set_page_dat(ptdesc_page(ptdesc), 0);
>  	/* Initialize page table */
> -	table = (unsigned long *) page_to_virt(page);
> +	table = (unsigned long *) ptdesc_to_virt(ptdesc);
>  	if (mm_alloc_pgste(mm)) {
>  		/* Return 4K page table with PGSTEs */
> -		atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
> +		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
>  		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
>  		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
>  	} else {
>  		/* Return the first 2K fragment of the page */
> -		atomic_xor_bits(&page->pt_frag_refcount, 0x01U);
> +		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x01U);
>  		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
>  		spin_lock_bh(&mm->context.lock);
> -		list_add(&page->lru, &mm->context.pgtable_list);
> +		list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
>  		spin_unlock_bh(&mm->context.lock);
>  	}
>  	return table;
> @@ -309,9 +309,8 @@ static void page_table_release_check(struct page *page, void *table,
>  void page_table_free(struct mm_struct *mm, unsigned long *table)
>  {
>  	unsigned int mask, bit, half;
> -	struct page *page;
> +	struct ptdesc *ptdesc = virt_to_ptdesc(table);
>  
> -	page = virt_to_page(table);
>  	if (!mm_alloc_pgste(mm)) {
>  		/* Free 2K page table fragment of a 4K page */
>  		bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
> @@ -321,39 +320,38 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
>  		 * will happen outside of the critical section from this
>  		 * function or from __tlb_remove_table()
>  		 */
> -		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
> +		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
>  		if (mask & 0x03U)
> -			list_add(&page->lru, &mm->context.pgtable_list);
> +			list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
>  		else
> -			list_del(&page->lru);
> +			list_del(&ptdesc->pt_list);
>  		spin_unlock_bh(&mm->context.lock);
> -		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x10U << bit);
> +		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x10U << bit);
>  		if (mask != 0x00U)
>  			return;
>  		half = 0x01U << bit;
>  	} else {
>  		half = 0x03U;
> -		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
> +		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
>  	}
>  
> -	page_table_release_check(page, table, half, mask);
> -	pgtable_pte_page_dtor(page);
> -	__free_page(page);
> +	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
>  			 unsigned long vmaddr)
>  {
>  	struct mm_struct *mm;
> -	struct page *page;
>  	unsigned int bit, mask;
> +	struct ptdesc *ptdesc = virt_to_ptdesc(table);
>  
>  	mm = tlb->mm;
> -	page = virt_to_page(table);
>  	if (mm_alloc_pgste(mm)) {
>  		gmap_unlink(mm, table, vmaddr);
>  		table = (unsigned long *) ((unsigned long)table | 0x03U);
> -		tlb_remove_table(tlb, table);
> +		tlb_remove_ptdesc(tlb, table);
>  		return;
>  	}
>  	bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
> @@ -363,11 +361,11 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
>  	 * outside of the critical section from __tlb_remove_table() or from
>  	 * page_table_free()
>  	 */
> -	mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
> +	mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
>  	if (mask & 0x03U)
> -		list_add_tail(&page->lru, &mm->context.pgtable_list);
> +		list_add_tail(&ptdesc->pt_list, &mm->context.pgtable_list);
>  	else
> -		list_del(&page->lru);
> +		list_del(&ptdesc->pt_list);
>  	spin_unlock_bh(&mm->context.lock);
>  	table = (unsigned long *) ((unsigned long) table | (0x01U << bit));
>  	tlb_remove_table(tlb, table);
> @@ -377,7 +375,7 @@ void __tlb_remove_table(void *_table)
>  {
>  	unsigned int mask = (unsigned long) _table & 0x03U, half = mask;
>  	void *table = (void *)((unsigned long) _table ^ mask);
> -	struct page *page = virt_to_page(table);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(table);
>  
>  	switch (half) {
>  	case 0x00U:	/* pmd, pud, or p4d */
> @@ -385,18 +383,18 @@ void __tlb_remove_table(void *_table)
>  		return;
>  	case 0x01U:	/* lower 2K of a 4K page table */
>  	case 0x02U:	/* higher 2K of a 4K page table */
> -		mask = atomic_xor_bits(&page->pt_frag_refcount, mask << 4);
> +		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, mask << 4);
>  		if (mask != 0x00U)
>  			return;
>  		break;
>  	case 0x03U:	/* 4K page table with pgstes */
> -		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
> +		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
>  		break;
>  	}
>  
> -	page_table_release_check(page, table, half, mask);
> -	pgtable_pte_page_dtor(page);
> -	__free_page(page);
> +	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  /*
> @@ -424,16 +422,20 @@ static void base_pgt_free(unsigned long *table)
>  static unsigned long *base_crst_alloc(unsigned long val)
>  {
>  	unsigned long *table;
> +	struct ptdesc *ptdesc;
>  
> -	table =	(unsigned long *)__get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
> -	if (table)
> -		crst_table_init(table, val);
> +	ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
> +	if (!ptdesc)
> +		return NULL;
> +	table = ptdesc_address(ptdesc);
> +
> +	crst_table_init(table, val);
>  	return table;
>  }
>  
>  static void base_crst_free(unsigned long *table)
>  {
> -	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
> +	pagetable_free(virt_to_ptdesc(table));
>  }
>  
>  #define BASE_ADDR_END_FUNC(NAME, SIZE)					\
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 18/34] mm: Remove page table members from struct page

[Vishal Moola (Oracle)]

The page table members are now split out into their own ptdesc struct.
Remove them from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm_types.h | 14 --------------
 include/linux/pgtable.h  |  3 ---
 2 files changed, 17 deletions(-)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 6161fe1ae5b8..31ffa1be21d0 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -141,20 +141,6 @@ struct page {
 		struct {	/* Tail pages of compound page */
 			unsigned long compound_head;	/* Bit zero is set */
 		};
-		struct {	/* Page table pages */
-			unsigned long _pt_pad_1;	/* compound_head */
-			pgtable_t pmd_huge_pte; /* protected by page->ptl */
-			unsigned long _pt_s390_gaddr;	/* mapping */
-			union {
-				struct mm_struct *pt_mm; /* x86 pgds only */
-				atomic_t pt_frag_refcount; /* powerpc */
-			};
-#if ALLOC_SPLIT_PTLOCKS
-			spinlock_t *ptl;
-#else
-			spinlock_t ptl;
-#endif
-		};
 		struct {	/* ZONE_DEVICE pages */
 			/** @pgmap: Points to the hosting device page map. */
 			struct dev_pagemap *pgmap;
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index c405f74d3875..33cc19d752b3 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1019,10 +1019,7 @@ struct ptdesc {
 TABLE_MATCH(flags, __page_flags);
 TABLE_MATCH(compound_head, pt_list);
 TABLE_MATCH(compound_head, _pt_pad_1);
-TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
 TABLE_MATCH(mapping, _pt_s390_gaddr);
-TABLE_MATCH(pt_mm, pt_mm);
-TABLE_MATCH(ptl, ptl);
 #undef TABLE_MATCH
 static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
 
-- 
2.40.1

Re: [PATCH v4 18/34] mm: Remove page table members from struct page

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:07PM -0700, Vishal Moola (Oracle) wrote:
> The page table members are now split out into their own ptdesc struct.
> Remove them from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  include/linux/mm_types.h | 14 --------------
>  include/linux/pgtable.h  |  3 ---
>  2 files changed, 17 deletions(-)
> 
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 6161fe1ae5b8..31ffa1be21d0 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -141,20 +141,6 @@ struct page {
>  		struct {	/* Tail pages of compound page */
>  			unsigned long compound_head;	/* Bit zero is set */
>  		};
> -		struct {	/* Page table pages */
> -			unsigned long _pt_pad_1;	/* compound_head */
> -			pgtable_t pmd_huge_pte; /* protected by page->ptl */
> -			unsigned long _pt_s390_gaddr;	/* mapping */
> -			union {
> -				struct mm_struct *pt_mm; /* x86 pgds only */
> -				atomic_t pt_frag_refcount; /* powerpc */
> -			};
> -#if ALLOC_SPLIT_PTLOCKS
> -			spinlock_t *ptl;
> -#else
> -			spinlock_t ptl;
> -#endif
> -		};
>  		struct {	/* ZONE_DEVICE pages */
>  			/** @pgmap: Points to the hosting device page map. */
>  			struct dev_pagemap *pgmap;
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index c405f74d3875..33cc19d752b3 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -1019,10 +1019,7 @@ struct ptdesc {
>  TABLE_MATCH(flags, __page_flags);
>  TABLE_MATCH(compound_head, pt_list);
>  TABLE_MATCH(compound_head, _pt_pad_1);
> -TABLE_MATCH(pmd_huge_pte, pmd_huge_pte);
>  TABLE_MATCH(mapping, _pt_s390_gaddr);
> -TABLE_MATCH(pt_mm, pt_mm);
> -TABLE_MATCH(ptl, ptl);
>  #undef TABLE_MATCH
>  static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 19/34] pgalloc: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/asm-generic/pgalloc.h | 62 +++++++++++++++++++++--------------
 1 file changed, 37 insertions(+), 25 deletions(-)

diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index a7cf825befae..3fd6ce79e654 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -18,7 +18,11 @@
  */
 static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
 {
-	return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL, 0);
+
+	if (!ptdesc)
+		return NULL;
+	return ptdesc_address(ptdesc);
 }
 
 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
@@ -41,7 +45,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
  */
 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 {
-	free_page((unsigned long)pte);
+	pagetable_free(virt_to_ptdesc(pte));
 }
 
 /**
@@ -49,7 +53,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  * @mm: the mm_struct of the current context
  * @gfp: GFP flags to use for the allocation
  *
- * Allocates a page and runs the pgtable_pte_page_ctor().
+ * Allocates a ptdesc and runs the pagetable_pte_ctor().
  *
  * This function is intended for architectures that need
  * anything beyond simple page allocation or must have custom GFP flags.
@@ -58,17 +62,17 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  */
 static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
 {
-	struct page *pte;
+	struct ptdesc *ptdesc;
 
-	pte = alloc_page(gfp);
-	if (!pte)
+	ptdesc = pagetable_alloc(gfp, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(pte)) {
-		__free_page(pte);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	return pte;
+	return ptdesc_page(ptdesc);
 }
 
 #ifndef __HAVE_ARCH_PTE_ALLOC_ONE
@@ -76,7 +80,7 @@ static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
  * pte_alloc_one - allocate a page for PTE-level user page table
  * @mm: the mm_struct of the current context
  *
- * Allocates a page and runs the pgtable_pte_page_ctor().
+ * Allocates a ptdesc and runs the pagetable_pte_ctor().
  *
  * Return: `struct page` initialized as page table or %NULL on error
  */
@@ -98,8 +102,10 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
  */
 static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
 {
-	pgtable_pte_page_dtor(pte_page);
-	__free_page(pte_page);
+	struct ptdesc *ptdesc = page_ptdesc(pte_page);
+
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 
@@ -110,7 +116,7 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
  * pmd_alloc_one - allocate a page for PMD-level page table
  * @mm: the mm_struct of the current context
  *
- * Allocates a page and runs the pgtable_pmd_page_ctor().
+ * Allocates a ptdesc and runs the pagetable_pmd_ctor().
  * Allocations use %GFP_PGTABLE_USER in user context and
  * %GFP_PGTABLE_KERNEL in kernel context.
  *
@@ -118,28 +124,30 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
  */
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	gfp_t gfp = GFP_PGTABLE_USER;
 
 	if (mm == &init_mm)
 		gfp = GFP_PGTABLE_KERNEL;
-	page = alloc_page(gfp);
-	if (!page)
+	ptdesc = pagetable_alloc(gfp, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pmd_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pmd_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
-	return (pmd_t *)page_address(page);
+	return ptdesc_address(ptdesc);
 }
 #endif
 
 #ifndef __HAVE_ARCH_PMD_FREE
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
+	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
+
 	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
-	free_page((unsigned long)pmd);
+	pagetable_pmd_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 #endif
 
@@ -149,11 +157,15 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 
 static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	gfp_t gfp = GFP_PGTABLE_USER;
+	gfp_t gfp = GFP_PGTABLE_USER | __GFP_ZERO;
+	struct ptdesc *ptdesc;
 
 	if (mm == &init_mm)
 		gfp = GFP_PGTABLE_KERNEL;
-	return (pud_t *)get_zeroed_page(gfp);
+	ptdesc = pagetable_alloc(gfp, 0);
+	if (!ptdesc)
+		return NULL;
+	return ptdesc_address(ptdesc);
 }
 
 #ifndef __HAVE_ARCH_PUD_ALLOC_ONE
@@ -175,7 +187,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
 {
 	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
-	free_page((unsigned long)pud);
+	pagetable_free(virt_to_ptdesc(pud));
 }
 
 #ifndef __HAVE_ARCH_PUD_FREE
@@ -190,7 +202,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
 #ifndef __HAVE_ARCH_PGD_FREE
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-	free_page((unsigned long)pgd);
+	pagetable_free(virt_to_ptdesc(pgd));
 }
 #endif
 
-- 
2.40.1

Re: [PATCH v4 19/34] pgalloc: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:08PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>  include/asm-generic/pgalloc.h | 62 +++++++++++++++++++++--------------
>  1 file changed, 37 insertions(+), 25 deletions(-)
> 
> diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
> index a7cf825befae..3fd6ce79e654 100644
> --- a/include/asm-generic/pgalloc.h
> +++ b/include/asm-generic/pgalloc.h
> @@ -18,7 +18,11 @@
>   */
>  static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
>  {
> -	return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL, 0);
> +
> +	if (!ptdesc)
> +		return NULL;
> +	return ptdesc_address(ptdesc);
>  }
>  
>  #ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
> @@ -41,7 +45,7 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
>   */
>  static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
>  {
> -	free_page((unsigned long)pte);
> +	pagetable_free(virt_to_ptdesc(pte));
>  }
>  
>  /**
> @@ -49,7 +53,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
>   * @mm: the mm_struct of the current context
>   * @gfp: GFP flags to use for the allocation
>   *
> - * Allocates a page and runs the pgtable_pte_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pte_ctor().

Allocates memory for page table and ptdesc

>   *
>   * This function is intended for architectures that need
>   * anything beyond simple page allocation or must have custom GFP flags.

The Return: description here should be fixed up

> @@ -58,17 +62,17 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
>   */
>  static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
>  {
> -	struct page *pte;
> +	struct ptdesc *ptdesc;
>  
> -	pte = alloc_page(gfp);
> -	if (!pte)
> +	ptdesc = pagetable_alloc(gfp, 0);
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pte_page_ctor(pte)) {
> -		__free_page(pte);
> +	if (!pagetable_pte_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	return pte;
> +	return ptdesc_page(ptdesc);
>  }
>  
>  #ifndef __HAVE_ARCH_PTE_ALLOC_ONE
> @@ -76,7 +80,7 @@ static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
>   * pte_alloc_one - allocate a page for PTE-level user page table
>   * @mm: the mm_struct of the current context
>   *
> - * Allocates a page and runs the pgtable_pte_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pte_ctor().

Allocates memory for page table and ptdesc

>   *
>   * Return: `struct page` initialized as page table or %NULL on error

Return: ptdesc ...

>   */
> @@ -98,8 +102,10 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
>   */
>  static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
>  {
> -	pgtable_pte_page_dtor(pte_page);
> -	__free_page(pte_page);
> +	struct ptdesc *ptdesc = page_ptdesc(pte_page);
> +
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  
> @@ -110,7 +116,7 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
>   * pmd_alloc_one - allocate a page for PMD-level page table
>   * @mm: the mm_struct of the current context
>   *
> - * Allocates a page and runs the pgtable_pmd_page_ctor().
> + * Allocates a ptdesc and runs the pagetable_pmd_ctor().

Allocate memory for page table and ptdesc

>   * Allocations use %GFP_PGTABLE_USER in user context and
>   * %GFP_PGTABLE_KERNEL in kernel context.
>   *
> @@ -118,28 +124,30 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
>   */
>  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
>  {
> -	struct page *page;
> +	struct ptdesc *ptdesc;
>  	gfp_t gfp = GFP_PGTABLE_USER;
>  
>  	if (mm == &init_mm)
>  		gfp = GFP_PGTABLE_KERNEL;
> -	page = alloc_page(gfp);
> -	if (!page)
> +	ptdesc = pagetable_alloc(gfp, 0);
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pmd_page_ctor(page)) {
> -		__free_page(page);
> +	if (!pagetable_pmd_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
> -	return (pmd_t *)page_address(page);
> +	return ptdesc_address(ptdesc);
>  }
>  #endif
>  
>  #ifndef __HAVE_ARCH_PMD_FREE
>  static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
>  {
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
> +
>  	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
> -	pgtable_pmd_page_dtor(virt_to_page(pmd));
> -	free_page((unsigned long)pmd);
> +	pagetable_pmd_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  #endif
>  
> @@ -149,11 +157,15 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
>  
>  static inline pud_t *__pud_alloc_one(struct mm_struct *mm, unsigned long addr)
>  {
> -	gfp_t gfp = GFP_PGTABLE_USER;
> +	gfp_t gfp = GFP_PGTABLE_USER | __GFP_ZERO;

GFP_PGTABLE_USER already contains __GFP_ZERO

> +	struct ptdesc *ptdesc;
>  
>  	if (mm == &init_mm)
>  		gfp = GFP_PGTABLE_KERNEL;
> -	return (pud_t *)get_zeroed_page(gfp);
> +	ptdesc = pagetable_alloc(gfp, 0);
> +	if (!ptdesc)
> +		return NULL;
> +	return ptdesc_address(ptdesc);
>  }
>  
>  #ifndef __HAVE_ARCH_PUD_ALLOC_ONE
> @@ -175,7 +187,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
>  static inline void __pud_free(struct mm_struct *mm, pud_t *pud)
>  {
>  	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
> -	free_page((unsigned long)pud);
> +	pagetable_free(virt_to_ptdesc(pud));
>  }
>  
>  #ifndef __HAVE_ARCH_PUD_FREE
> @@ -190,7 +202,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
>  #ifndef __HAVE_ARCH_PGD_FREE
>  static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
>  {
> -	free_page((unsigned long)pgd);
> +	pagetable_free(virt_to_ptdesc(pgd));
>  }
>  #endif
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 20/34] arm: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

late_alloc() also uses the __get_free_pages() helper function. Convert
this to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/arm/include/asm/tlb.h | 12 +++++++-----
 arch/arm/mm/mmu.c          |  6 +++---
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index b8cbe03ad260..f40d06ad5d2a 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h
@@ -39,7 +39,9 @@ static inline void __tlb_remove_table(void *_table)
 static inline void
 __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
 {
-	pgtable_pte_page_dtor(pte);
+	struct ptdesc *ptdesc = page_ptdesc(pte);
+
+	pagetable_pte_dtor(ptdesc);
 
 #ifndef CONFIG_ARM_LPAE
 	/*
@@ -50,17 +52,17 @@ __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
 	__tlb_adjust_range(tlb, addr - PAGE_SIZE, 2 * PAGE_SIZE);
 #endif
 
-	tlb_remove_table(tlb, pte);
+	tlb_remove_ptdesc(tlb, ptdesc);
 }
 
 static inline void
 __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
 {
 #ifdef CONFIG_ARM_LPAE
-	struct page *page = virt_to_page(pmdp);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pmdp);
 
-	pgtable_pmd_page_dtor(page);
-	tlb_remove_table(tlb, page);
+	pagetable_pmd_dtor(ptdesc);
+	tlb_remove_ptdesc(tlb, ptdesc);
 #endif
 }
 
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 22292cf3381c..294518fd0240 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -737,11 +737,11 @@ static void __init *early_alloc(unsigned long sz)
 
 static void *__init late_alloc(unsigned long sz)
 {
-	void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz));
+	void *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL, get_order(sz));
 
-	if (!ptr || !pgtable_pte_page_ctor(virt_to_page(ptr)))
+	if (!ptdesc || !pagetable_pte_ctor(ptdesc))
 		BUG();
-	return ptr;
+	return ptdesc;
 }
 
 static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr,
-- 
2.40.1

Re: [PATCH v4 20/34] arm: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:09PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> late_alloc() also uses the __get_free_pages() helper function. Convert
> this to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

One comment below.

> ---
>  arch/arm/include/asm/tlb.h | 12 +++++++-----
>  arch/arm/mm/mmu.c          |  6 +++---
>  2 files changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
> index b8cbe03ad260..f40d06ad5d2a 100644
> --- a/arch/arm/include/asm/tlb.h
> +++ b/arch/arm/include/asm/tlb.h
> @@ -39,7 +39,9 @@ static inline void __tlb_remove_table(void *_table)
>  static inline void
>  __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
>  {
> -	pgtable_pte_page_dtor(pte);
> +	struct ptdesc *ptdesc = page_ptdesc(pte);
> +
> +	pagetable_pte_dtor(ptdesc);
>  
>  #ifndef CONFIG_ARM_LPAE
>  	/*
> @@ -50,17 +52,17 @@ __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
>  	__tlb_adjust_range(tlb, addr - PAGE_SIZE, 2 * PAGE_SIZE);
>  #endif
>  
> -	tlb_remove_table(tlb, pte);
> +	tlb_remove_ptdesc(tlb, ptdesc);
>  }
>  
>  static inline void
>  __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
>  {
>  #ifdef CONFIG_ARM_LPAE
> -	struct page *page = virt_to_page(pmdp);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pmdp);
>  
> -	pgtable_pmd_page_dtor(page);
> -	tlb_remove_table(tlb, page);
> +	pagetable_pmd_dtor(ptdesc);
> +	tlb_remove_ptdesc(tlb, ptdesc);
>  #endif
>  }
>  
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index 22292cf3381c..294518fd0240 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -737,11 +737,11 @@ static void __init *early_alloc(unsigned long sz)
>  
>  static void *__init late_alloc(unsigned long sz)
>  {
> -	void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz));
> +	void *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL, get_order(sz));
>  
> -	if (!ptr || !pgtable_pte_page_ctor(virt_to_page(ptr)))
> +	if (!ptdesc || !pagetable_pte_ctor(ptdesc))
>  		BUG();
> -	return ptr;
> +	return ptdesc;

should be

	return  ptdesc_to_virt(ptdesc);

>  }
>  
>  static pte_t * __init arm_pte_alloc(pmd_t *pmd, unsigned long addr,
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 21/34] arm64: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/arm64/include/asm/tlb.h | 14 ++++++++------
 arch/arm64/mm/mmu.c          |  7 ++++---
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index c995d1f4594f..2c29239d05c3 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -75,18 +75,20 @@ static inline void tlb_flush(struct mmu_gather *tlb)
 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
 				  unsigned long addr)
 {
-	pgtable_pte_page_dtor(pte);
-	tlb_remove_table(tlb, pte);
+	struct ptdesc *ptdesc = page_ptdesc(pte);
+
+	pagetable_pte_dtor(ptdesc);
+	tlb_remove_ptdesc(tlb, ptdesc);
 }
 
 #if CONFIG_PGTABLE_LEVELS > 2
 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 				  unsigned long addr)
 {
-	struct page *page = virt_to_page(pmdp);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pmdp);
 
-	pgtable_pmd_page_dtor(page);
-	tlb_remove_table(tlb, page);
+	pagetable_pmd_dtor(ptdesc);
+	tlb_remove_ptdesc(tlb, ptdesc);
 }
 #endif
 
@@ -94,7 +96,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
 				  unsigned long addr)
 {
-	tlb_remove_table(tlb, virt_to_page(pudp));
+	tlb_remove_ptdesc(tlb, virt_to_ptdesc(pudp));
 }
 #endif
 
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index af6bc8403ee4..5867a0e917b9 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -426,6 +426,7 @@ static phys_addr_t __pgd_pgtable_alloc(int shift)
 static phys_addr_t pgd_pgtable_alloc(int shift)
 {
 	phys_addr_t pa = __pgd_pgtable_alloc(shift);
+	struct ptdesc *ptdesc = page_ptdesc(phys_to_page(pa));
 
 	/*
 	 * Call proper page table ctor in case later we need to
@@ -433,12 +434,12 @@ static phys_addr_t pgd_pgtable_alloc(int shift)
 	 * this pre-allocated page table.
 	 *
 	 * We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is
-	 * folded, and if so pgtable_pmd_page_ctor() becomes nop.
+	 * folded, and if so pagetable_pte_ctor() becomes nop.
 	 */
 	if (shift == PAGE_SHIFT)
-		BUG_ON(!pgtable_pte_page_ctor(phys_to_page(pa)));
+		BUG_ON(!pagetable_pte_ctor(ptdesc));
 	else if (shift == PMD_SHIFT)
-		BUG_ON(!pgtable_pmd_page_ctor(phys_to_page(pa)));
+		BUG_ON(!pagetable_pmd_ctor(ptdesc));
 
 	return pa;
 }
-- 
2.40.1

Re: [PATCH v4 21/34] arm64: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:10PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/arm64/include/asm/tlb.h | 14 ++++++++------
>  arch/arm64/mm/mmu.c          |  7 ++++---
>  2 files changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
> index c995d1f4594f..2c29239d05c3 100644
> --- a/arch/arm64/include/asm/tlb.h
> +++ b/arch/arm64/include/asm/tlb.h
> @@ -75,18 +75,20 @@ static inline void tlb_flush(struct mmu_gather *tlb)
>  static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
>  				  unsigned long addr)
>  {
> -	pgtable_pte_page_dtor(pte);
> -	tlb_remove_table(tlb, pte);
> +	struct ptdesc *ptdesc = page_ptdesc(pte);
> +
> +	pagetable_pte_dtor(ptdesc);
> +	tlb_remove_ptdesc(tlb, ptdesc);
>  }
>  
>  #if CONFIG_PGTABLE_LEVELS > 2
>  static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
>  				  unsigned long addr)
>  {
> -	struct page *page = virt_to_page(pmdp);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pmdp);
>  
> -	pgtable_pmd_page_dtor(page);
> -	tlb_remove_table(tlb, page);
> +	pagetable_pmd_dtor(ptdesc);
> +	tlb_remove_ptdesc(tlb, ptdesc);
>  }
>  #endif
>  
> @@ -94,7 +96,7 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
>  static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
>  				  unsigned long addr)
>  {
> -	tlb_remove_table(tlb, virt_to_page(pudp));
> +	tlb_remove_ptdesc(tlb, virt_to_ptdesc(pudp));
>  }
>  #endif
>  
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index af6bc8403ee4..5867a0e917b9 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -426,6 +426,7 @@ static phys_addr_t __pgd_pgtable_alloc(int shift)
>  static phys_addr_t pgd_pgtable_alloc(int shift)
>  {
>  	phys_addr_t pa = __pgd_pgtable_alloc(shift);
> +	struct ptdesc *ptdesc = page_ptdesc(phys_to_page(pa));
>  
>  	/*
>  	 * Call proper page table ctor in case later we need to
> @@ -433,12 +434,12 @@ static phys_addr_t pgd_pgtable_alloc(int shift)
>  	 * this pre-allocated page table.
>  	 *
>  	 * We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is
> -	 * folded, and if so pgtable_pmd_page_ctor() becomes nop.
> +	 * folded, and if so pagetable_pte_ctor() becomes nop.
>  	 */
>  	if (shift == PAGE_SHIFT)
> -		BUG_ON(!pgtable_pte_page_ctor(phys_to_page(pa)));
> +		BUG_ON(!pagetable_pte_ctor(ptdesc));
>  	else if (shift == PMD_SHIFT)
> -		BUG_ON(!pgtable_pmd_page_ctor(phys_to_page(pa)));
> +		BUG_ON(!pagetable_pmd_ctor(ptdesc));
>  
>  	return pa;
>  }
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

Re: [PATCH v4 21/34] arm64: Convert various functions to use ptdescs

[Catalin Marinas]

On Mon, Jun 12, 2023 at 02:04:10PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

[PATCH v4 22/34] csky: Convert __pte_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Guo Ren <guoren@kernel.org>
---
 arch/csky/include/asm/pgalloc.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h
index 7d57e5da0914..9c84c9012e53 100644
--- a/arch/csky/include/asm/pgalloc.h
+++ b/arch/csky/include/asm/pgalloc.h
@@ -63,8 +63,8 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 
 #define __pte_free_tlb(tlb, pte, address)		\
 do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page(tlb, pte);			\
+	pagetable_pte_dtor(page_ptdesc(pte));		\
+	tlb_remove_page_ptdesc(tlb, page_ptdesc(pte));	\
 } while (0)
 
 extern void pagetable_init(void);
-- 
2.40.1

Re: [PATCH v4 22/34] csky: Convert __pte_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:11PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> Acked-by: Guo Ren <guoren@kernel.org>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/csky/include/asm/pgalloc.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h
> index 7d57e5da0914..9c84c9012e53 100644
> --- a/arch/csky/include/asm/pgalloc.h
> +++ b/arch/csky/include/asm/pgalloc.h
> @@ -63,8 +63,8 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
>  
>  #define __pte_free_tlb(tlb, pte, address)		\
>  do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page(tlb, pte);			\
> +	pagetable_pte_dtor(page_ptdesc(pte));		\
> +	tlb_remove_page_ptdesc(tlb, page_ptdesc(pte));	\
>  } while (0)
>  
>  extern void pagetable_init(void);
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 23/34] hexagon: Convert __pte_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/hexagon/include/asm/pgalloc.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/hexagon/include/asm/pgalloc.h b/arch/hexagon/include/asm/pgalloc.h
index f0c47e6a7427..55988625e6fb 100644
--- a/arch/hexagon/include/asm/pgalloc.h
+++ b/arch/hexagon/include/asm/pgalloc.h
@@ -87,10 +87,10 @@ static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
 		max_kernel_seg = pmdindex;
 }
 
-#define __pte_free_tlb(tlb, pte, addr)		\
-do {						\
-	pgtable_pte_page_dtor((pte));		\
-	tlb_remove_page((tlb), (pte));		\
+#define __pte_free_tlb(tlb, pte, addr)				\
+do {								\
+	pagetable_pte_dtor((page_ptdesc(pte)));			\
+	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
 } while (0)
 
 #endif
-- 
2.40.1

Re: [PATCH v4 23/34] hexagon: Convert __pte_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:12PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/hexagon/include/asm/pgalloc.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/hexagon/include/asm/pgalloc.h b/arch/hexagon/include/asm/pgalloc.h
> index f0c47e6a7427..55988625e6fb 100644
> --- a/arch/hexagon/include/asm/pgalloc.h
> +++ b/arch/hexagon/include/asm/pgalloc.h
> @@ -87,10 +87,10 @@ static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
>  		max_kernel_seg = pmdindex;
>  }
>  
> -#define __pte_free_tlb(tlb, pte, addr)		\
> -do {						\
> -	pgtable_pte_page_dtor((pte));		\
> -	tlb_remove_page((tlb), (pte));		\
> +#define __pte_free_tlb(tlb, pte, addr)				\
> +do {								\
> +	pagetable_pte_dtor((page_ptdesc(pte)));			\
> +	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>  } while (0)
>  
>  #endif
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 24/34] loongarch: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/loongarch/include/asm/pgalloc.h | 27 +++++++++++++++------------
 arch/loongarch/mm/pgtable.c          |  7 ++++---
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
index af1d1e4a6965..70bb3bdd201e 100644
--- a/arch/loongarch/include/asm/pgalloc.h
+++ b/arch/loongarch/include/asm/pgalloc.h
@@ -45,9 +45,9 @@ extern void pagetable_init(void);
 extern pgd_t *pgd_alloc(struct mm_struct *mm);
 
 #define __pte_free_tlb(tlb, pte, address)			\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb), pte);			\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
 } while (0)
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -55,18 +55,18 @@ do {							\
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pmd_t *pmd;
-	struct page *pg;
+	struct ptdesc *ptdesc;
 
-	pg = alloc_page(GFP_KERNEL_ACCOUNT);
-	if (!pg)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, 0);
+	if (!ptdesc)
 		return NULL;
 
-	if (!pgtable_pmd_page_ctor(pg)) {
-		__free_page(pg);
+	if (!pagetable_pmd_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	pmd = (pmd_t *)page_address(pg);
+	pmd = ptdesc_address(ptdesc);
 	pmd_init(pmd);
 	return pmd;
 }
@@ -80,10 +80,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pud_t *pud;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
 
-	pud = (pud_t *) __get_free_page(GFP_KERNEL);
-	if (pud)
-		pud_init(pud);
+	if (!ptdesc)
+		return NULL;
+	pud = ptdesc_address(ptdesc);
+
+	pud_init(pud);
 	return pud;
 }
 
diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
index 36a6dc0148ae..cdba10ffc0df 100644
--- a/arch/loongarch/mm/pgtable.c
+++ b/arch/loongarch/mm/pgtable.c
@@ -11,10 +11,11 @@
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	pgd_t *ret, *init;
+	pgd_t *init, *ret = NULL;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
 
-	ret = (pgd_t *) __get_free_page(GFP_KERNEL);
-	if (ret) {
+	if (ptdesc) {
+		ret = (pgd_t *)ptdesc_address(ptdesc);
 		init = pgd_offset(&init_mm, 0UL);
 		pgd_init(ret);
 		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
-- 
2.40.1

Re: [PATCH v4 24/34] loongarch: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:13PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/loongarch/include/asm/pgalloc.h | 27 +++++++++++++++------------
>  arch/loongarch/mm/pgtable.c          |  7 ++++---
>  2 files changed, 19 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
> index af1d1e4a6965..70bb3bdd201e 100644
> --- a/arch/loongarch/include/asm/pgalloc.h
> +++ b/arch/loongarch/include/asm/pgalloc.h
> @@ -45,9 +45,9 @@ extern void pagetable_init(void);
>  extern pgd_t *pgd_alloc(struct mm_struct *mm);
>  
>  #define __pte_free_tlb(tlb, pte, address)			\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb), pte);			\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
>  } while (0)
>  
>  #ifndef __PAGETABLE_PMD_FOLDED
> @@ -55,18 +55,18 @@ do {							\
>  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pmd_t *pmd;
> -	struct page *pg;
> +	struct ptdesc *ptdesc;
>  
> -	pg = alloc_page(GFP_KERNEL_ACCOUNT);
> -	if (!pg)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, 0);
> +	if (!ptdesc)
>  		return NULL;
>  
> -	if (!pgtable_pmd_page_ctor(pg)) {
> -		__free_page(pg);
> +	if (!pagetable_pmd_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	pmd = (pmd_t *)page_address(pg);
> +	pmd = ptdesc_address(ptdesc);
>  	pmd_init(pmd);
>  	return pmd;
>  }
> @@ -80,10 +80,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pud_t *pud;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	pud = (pud_t *) __get_free_page(GFP_KERNEL);
> -	if (pud)
> -		pud_init(pud);
> +	if (!ptdesc)
> +		return NULL;
> +	pud = ptdesc_address(ptdesc);
> +
> +	pud_init(pud);
>  	return pud;
>  }
>  
> diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
> index 36a6dc0148ae..cdba10ffc0df 100644
> --- a/arch/loongarch/mm/pgtable.c
> +++ b/arch/loongarch/mm/pgtable.c
> @@ -11,10 +11,11 @@
>  
>  pgd_t *pgd_alloc(struct mm_struct *mm)
>  {
> -	pgd_t *ret, *init;
> +	pgd_t *init, *ret = NULL;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	ret = (pgd_t *) __get_free_page(GFP_KERNEL);
> -	if (ret) {
> +	if (ptdesc) {
> +		ret = (pgd_t *)ptdesc_address(ptdesc);
>  		init = pgd_offset(&init_mm, 0UL);
>  		pgd_init(ret);
>  		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 25/34] m68k: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/m68k/include/asm/mcf_pgalloc.h  | 41 ++++++++++++++--------------
 arch/m68k/include/asm/sun3_pgalloc.h |  8 +++---
 arch/m68k/mm/motorola.c              |  4 +--
 3 files changed, 27 insertions(+), 26 deletions(-)

diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h
index 5c2c0a864524..857949ac9431 100644
--- a/arch/m68k/include/asm/mcf_pgalloc.h
+++ b/arch/m68k/include/asm/mcf_pgalloc.h
@@ -7,20 +7,19 @@
 
 extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 {
-	free_page((unsigned long) pte);
+	pagetable_free(virt_to_ptdesc(pte));
 }
 
 extern const char bad_pmd_string[];
 
 extern inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
 {
-	unsigned long page = __get_free_page(GFP_DMA);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA | __GFP_ZERO, 0);
 
-	if (!page)
+	if (!ptdesc)
 		return NULL;
 
-	memset((void *)page, 0, PAGE_SIZE);
-	return (pte_t *) (page);
+	return ptdesc_address(ptdesc);
 }
 
 extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
@@ -35,36 +34,36 @@ extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
 static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable,
 				  unsigned long address)
 {
-	struct page *page = virt_to_page(pgtable);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
 
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
 {
-	struct page *page = alloc_pages(GFP_DMA, 0);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA, 0);
 	pte_t *pte;
 
-	if (!page)
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	pte = page_address(page);
-	clear_page(pte);
+	pte = ptdesc_address(ptdesc);
+	pagetable_clear(pte);
 
 	return pte;
 }
 
 static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
 {
-	struct page *page = virt_to_page(pgtable);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
 
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 /*
@@ -75,16 +74,18 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-	free_page((unsigned long) pgd);
+	pagetable_free(virt_to_ptdesc(pgd));
 }
 
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	pgd_t *new_pgd;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA | GFP_NOWARN, 0);
 
-	new_pgd = (pgd_t *)__get_free_page(GFP_DMA | __GFP_NOWARN);
-	if (!new_pgd)
+	if (!ptdesc)
 		return NULL;
+	new_pgd = ptdesc_address(ptdesc);
+
 	memcpy(new_pgd, swapper_pg_dir, PTRS_PER_PGD * sizeof(pgd_t));
 	memset(new_pgd, 0, PAGE_OFFSET >> PGDIR_SHIFT);
 	return new_pgd;
diff --git a/arch/m68k/include/asm/sun3_pgalloc.h b/arch/m68k/include/asm/sun3_pgalloc.h
index 198036aff519..ff48573db2c0 100644
--- a/arch/m68k/include/asm/sun3_pgalloc.h
+++ b/arch/m68k/include/asm/sun3_pgalloc.h
@@ -17,10 +17,10 @@
 
 extern const char bad_pmd_string[];
 
-#define __pte_free_tlb(tlb,pte,addr)			\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb), pte);			\
+#define __pte_free_tlb(tlb, pte, addr)				\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
 } while (0)
 
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index c75984e2d86b..594575a0780c 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -161,7 +161,7 @@ void *get_pointer_table(int type)
 			 * m68k doesn't have SPLIT_PTE_PTLOCKS for not having
 			 * SMP.
 			 */
-			pgtable_pte_page_ctor(virt_to_page(page));
+			pagetable_pte_ctor(virt_to_ptdesc(page));
 		}
 
 		mmu_page_ctor(page);
@@ -201,7 +201,7 @@ int free_pointer_table(void *table, int type)
 		list_del(dp);
 		mmu_page_dtor((void *)page);
 		if (type == TABLE_PTE)
-			pgtable_pte_page_dtor(virt_to_page((void *)page));
+			pagetable_pte_dtor(virt_to_ptdesc((void *)page));
 		free_page (page);
 		return 1;
 	} else if (ptable_list[type].next != dp) {
-- 
2.40.1

Re: [PATCH v4 25/34] m68k: Convert various functions to use ptdescs

[Geert Uytterhoeven]

On Mon, Jun 12, 2023 at 11:05 PM Vishal Moola (Oracle)
<vishal.moola@gmail.com> wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
>
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
>
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v4 25/34] m68k: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:14PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

One comment below
> ---
>  arch/m68k/include/asm/mcf_pgalloc.h  | 41 ++++++++++++++--------------
>  arch/m68k/include/asm/sun3_pgalloc.h |  8 +++---
>  arch/m68k/mm/motorola.c              |  4 +--
>  3 files changed, 27 insertions(+), 26 deletions(-)
> 
> diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h
> index 5c2c0a864524..857949ac9431 100644
> --- a/arch/m68k/include/asm/mcf_pgalloc.h
> +++ b/arch/m68k/include/asm/mcf_pgalloc.h
> @@ -7,20 +7,19 @@
>  
>  extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
>  {
> -	free_page((unsigned long) pte);
> +	pagetable_free(virt_to_ptdesc(pte));
>  }
>  
>  extern const char bad_pmd_string[];
>  
>  extern inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
>  {
> -	unsigned long page = __get_free_page(GFP_DMA);
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA | __GFP_ZERO, 0);
>  
> -	if (!page)
> +	if (!ptdesc)
>  		return NULL;
>  
> -	memset((void *)page, 0, PAGE_SIZE);
> -	return (pte_t *) (page);
> +	return ptdesc_address(ptdesc);
>  }
>  
>  extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
> @@ -35,36 +34,36 @@ extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address)
>  static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable,
>  				  unsigned long address)
>  {
> -	struct page *page = virt_to_page(pgtable);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
>  
> -	pgtable_pte_page_dtor(page);
> -	__free_page(page);
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
>  {
> -	struct page *page = alloc_pages(GFP_DMA, 0);
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA, 0);

You can add __GFP_ZERO here and drop pagetable_clear() below

>  	pte_t *pte;
>  
> -	if (!page)
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pte_page_ctor(page)) {
> -		__free_page(page);
> +	if (!pagetable_pte_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	pte = page_address(page);
> -	clear_page(pte);
> +	pte = ptdesc_address(ptdesc);
> +	pagetable_clear(pte);
>  
>  	return pte;
>  }
>  
>  static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
>  {
> -	struct page *page = virt_to_page(pgtable);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pgtable);
>  
> -	pgtable_pte_page_dtor(page);
> -	__free_page(page);
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  /*
> @@ -75,16 +74,18 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
>  
>  static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
>  {
> -	free_page((unsigned long) pgd);
> +	pagetable_free(virt_to_ptdesc(pgd));
>  }
>  
>  static inline pgd_t *pgd_alloc(struct mm_struct *mm)
>  {
>  	pgd_t *new_pgd;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_DMA | GFP_NOWARN, 0);
>  
> -	new_pgd = (pgd_t *)__get_free_page(GFP_DMA | __GFP_NOWARN);
> -	if (!new_pgd)
> +	if (!ptdesc)
>  		return NULL;
> +	new_pgd = ptdesc_address(ptdesc);
> +
>  	memcpy(new_pgd, swapper_pg_dir, PTRS_PER_PGD * sizeof(pgd_t));
>  	memset(new_pgd, 0, PAGE_OFFSET >> PGDIR_SHIFT);
>  	return new_pgd;
> diff --git a/arch/m68k/include/asm/sun3_pgalloc.h b/arch/m68k/include/asm/sun3_pgalloc.h
> index 198036aff519..ff48573db2c0 100644
> --- a/arch/m68k/include/asm/sun3_pgalloc.h
> +++ b/arch/m68k/include/asm/sun3_pgalloc.h
> @@ -17,10 +17,10 @@
>  
>  extern const char bad_pmd_string[];
>  
> -#define __pte_free_tlb(tlb,pte,addr)			\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb), pte);			\
> +#define __pte_free_tlb(tlb, pte, addr)				\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
>  } while (0)
>  
>  static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
> diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
> index c75984e2d86b..594575a0780c 100644
> --- a/arch/m68k/mm/motorola.c
> +++ b/arch/m68k/mm/motorola.c
> @@ -161,7 +161,7 @@ void *get_pointer_table(int type)
>  			 * m68k doesn't have SPLIT_PTE_PTLOCKS for not having
>  			 * SMP.
>  			 */
> -			pgtable_pte_page_ctor(virt_to_page(page));
> +			pagetable_pte_ctor(virt_to_ptdesc(page));
>  		}
>  
>  		mmu_page_ctor(page);
> @@ -201,7 +201,7 @@ int free_pointer_table(void *table, int type)
>  		list_del(dp);
>  		mmu_page_dtor((void *)page);
>  		if (type == TABLE_PTE)
> -			pgtable_pte_page_dtor(virt_to_page((void *)page));
> +			pagetable_pte_dtor(virt_to_ptdesc((void *)page));
>  		free_page (page);
>  		return 1;
>  	} else if (ptable_list[type].next != dp) {
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 26/34] mips: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/mips/include/asm/pgalloc.h | 31 +++++++++++++++++--------------
 arch/mips/mm/pgtable.c          |  7 ++++---
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h
index f72e737dda21..6940e5536664 100644
--- a/arch/mips/include/asm/pgalloc.h
+++ b/arch/mips/include/asm/pgalloc.h
@@ -51,13 +51,13 @@ extern pgd_t *pgd_alloc(struct mm_struct *mm);
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 {
-	free_pages((unsigned long)pgd, PGD_TABLE_ORDER);
+	pagetable_free(virt_to_ptdesc(pgd));
 }
 
-#define __pte_free_tlb(tlb,pte,address)			\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb), pte);			\
+#define __pte_free_tlb(tlb, pte, address)			\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
 } while (0)
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -65,18 +65,18 @@ do {							\
 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pmd_t *pmd;
-	struct page *pg;
+	struct ptdesc *ptdesc;
 
-	pg = alloc_pages(GFP_KERNEL_ACCOUNT, PMD_TABLE_ORDER);
-	if (!pg)
+	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, PMD_TABLE_ORDER);
+	if (!ptdesc)
 		return NULL;
 
-	if (!pgtable_pmd_page_ctor(pg)) {
-		__free_pages(pg, PMD_TABLE_ORDER);
+	if (!pagetable_pmd_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
 
-	pmd = (pmd_t *)page_address(pg);
+	pmd = ptdesc_address(ptdesc);
 	pmd_init(pmd);
 	return pmd;
 }
@@ -90,10 +90,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
 {
 	pud_t *pud;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, PUD_TABLE_ORDER);
 
-	pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_TABLE_ORDER);
-	if (pud)
-		pud_init(pud);
+	if (!ptdesc)
+		return NULL;
+	pud = ptdesc_address(ptdesc);
+
+	pud_init(pud);
 	return pud;
 }
 
diff --git a/arch/mips/mm/pgtable.c b/arch/mips/mm/pgtable.c
index b13314be5d0e..729258ff4e3b 100644
--- a/arch/mips/mm/pgtable.c
+++ b/arch/mips/mm/pgtable.c
@@ -10,10 +10,11 @@
 
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	pgd_t *ret, *init;
+	pgd_t *init, *ret = NULL;
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, PGD_TABLE_ORDER);
 
-	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_TABLE_ORDER);
-	if (ret) {
+	if (ptdesc) {
+		ret = ptdesc_address(ptdesc);
 		init = pgd_offset(&init_mm, 0UL);
 		pgd_init(ret);
 		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
-- 
2.40.1

Re: [PATCH v4 26/34] mips: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:15PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/mips/include/asm/pgalloc.h | 31 +++++++++++++++++--------------
>  arch/mips/mm/pgtable.c          |  7 ++++---
>  2 files changed, 21 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h
> index f72e737dda21..6940e5536664 100644
> --- a/arch/mips/include/asm/pgalloc.h
> +++ b/arch/mips/include/asm/pgalloc.h
> @@ -51,13 +51,13 @@ extern pgd_t *pgd_alloc(struct mm_struct *mm);
>  
>  static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
>  {
> -	free_pages((unsigned long)pgd, PGD_TABLE_ORDER);
> +	pagetable_free(virt_to_ptdesc(pgd));
>  }
>  
> -#define __pte_free_tlb(tlb,pte,address)			\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb), pte);			\
> +#define __pte_free_tlb(tlb, pte, address)			\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));	\
>  } while (0)
>  
>  #ifndef __PAGETABLE_PMD_FOLDED
> @@ -65,18 +65,18 @@ do {							\
>  static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pmd_t *pmd;
> -	struct page *pg;
> +	struct ptdesc *ptdesc;
>  
> -	pg = alloc_pages(GFP_KERNEL_ACCOUNT, PMD_TABLE_ORDER);
> -	if (!pg)
> +	ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, PMD_TABLE_ORDER);
> +	if (!ptdesc)
>  		return NULL;
>  
> -	if (!pgtable_pmd_page_ctor(pg)) {
> -		__free_pages(pg, PMD_TABLE_ORDER);
> +	if (!pagetable_pmd_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
>  
> -	pmd = (pmd_t *)page_address(pg);
> +	pmd = ptdesc_address(ptdesc);
>  	pmd_init(pmd);
>  	return pmd;
>  }
> @@ -90,10 +90,13 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
>  static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>  {
>  	pud_t *pud;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, PUD_TABLE_ORDER);
>  
> -	pud = (pud_t *) __get_free_pages(GFP_KERNEL, PUD_TABLE_ORDER);
> -	if (pud)
> -		pud_init(pud);
> +	if (!ptdesc)
> +		return NULL;
> +	pud = ptdesc_address(ptdesc);
> +
> +	pud_init(pud);
>  	return pud;
>  }
>  
> diff --git a/arch/mips/mm/pgtable.c b/arch/mips/mm/pgtable.c
> index b13314be5d0e..729258ff4e3b 100644
> --- a/arch/mips/mm/pgtable.c
> +++ b/arch/mips/mm/pgtable.c
> @@ -10,10 +10,11 @@
>  
>  pgd_t *pgd_alloc(struct mm_struct *mm)
>  {
> -	pgd_t *ret, *init;
> +	pgd_t *init, *ret = NULL;
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, PGD_TABLE_ORDER);
>  
> -	ret = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_TABLE_ORDER);
> -	if (ret) {
> +	if (ptdesc) {
> +		ret = ptdesc_address(ptdesc);
>  		init = pgd_offset(&init_mm, 0UL);
>  		pgd_init(ret);
>  		memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 27/34] nios2: Convert __pte_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/nios2/include/asm/pgalloc.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/nios2/include/asm/pgalloc.h b/arch/nios2/include/asm/pgalloc.h
index ecd1657bb2ce..ce6bb8e74271 100644
--- a/arch/nios2/include/asm/pgalloc.h
+++ b/arch/nios2/include/asm/pgalloc.h
@@ -28,10 +28,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 
 extern pgd_t *pgd_alloc(struct mm_struct *mm);
 
-#define __pte_free_tlb(tlb, pte, addr)				\
-	do {							\
-		pgtable_pte_page_dtor(pte);			\
-		tlb_remove_page((tlb), (pte));			\
+#define __pte_free_tlb(tlb, pte, addr)					\
+	do {								\
+		pagetable_pte_dtor(page_ptdesc(pte));			\
+		tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
 	} while (0)
 
 #endif /* _ASM_NIOS2_PGALLOC_H */
-- 
2.40.1

Re: [PATCH v4 27/34] nios2: Convert __pte_free_tlb() to use ptdescs

[Dinh Nguyen]

On 6/12/23 16:04, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> ---
>   arch/nios2/include/asm/pgalloc.h | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/nios2/include/asm/pgalloc.h b/arch/nios2/include/asm/pgalloc.h
> index ecd1657bb2ce..ce6bb8e74271 100644
> --- a/arch/nios2/include/asm/pgalloc.h
> +++ b/arch/nios2/include/asm/pgalloc.h
> @@ -28,10 +28,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
>   
>   extern pgd_t *pgd_alloc(struct mm_struct *mm);
>   
> -#define __pte_free_tlb(tlb, pte, addr)				\
> -	do {							\
> -		pgtable_pte_page_dtor(pte);			\
> -		tlb_remove_page((tlb), (pte));			\
> +#define __pte_free_tlb(tlb, pte, addr)					\
> +	do {								\
> +		pagetable_pte_dtor(page_ptdesc(pte));			\
> +		tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>   	} while (0)
>   
>   #endif /* _ASM_NIOS2_PGALLOC_H */

Applied!

Thanks,
Dinh

Re: [PATCH v4 27/34] nios2: Convert __pte_free_tlb() to use ptdescs

[Geert Uytterhoeven]

Hi Dinh,

On Wed, Jun 14, 2023 at 12:17 AM Dinh Nguyen <dinguyen@kernel.org> wrote:
> On 6/12/23 16:04, Vishal Moola (Oracle) wrote:
> > Part of the conversions to replace pgtable constructor/destructors with
> > ptdesc equivalents.
> >
> > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > ---
> >   arch/nios2/include/asm/pgalloc.h | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/nios2/include/asm/pgalloc.h b/arch/nios2/include/asm/pgalloc.h
> > index ecd1657bb2ce..ce6bb8e74271 100644
> > --- a/arch/nios2/include/asm/pgalloc.h
> > +++ b/arch/nios2/include/asm/pgalloc.h
> > @@ -28,10 +28,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
> >
> >   extern pgd_t *pgd_alloc(struct mm_struct *mm);
> >
> > -#define __pte_free_tlb(tlb, pte, addr)                               \
> > -     do {                                                    \
> > -             pgtable_pte_page_dtor(pte);                     \
> > -             tlb_remove_page((tlb), (pte));                  \
> > +#define __pte_free_tlb(tlb, pte, addr)                                       \
> > +     do {                                                            \
> > +             pagetable_pte_dtor(page_ptdesc(pte));                   \
> > +             tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));      \
> >       } while (0)
> >
> >   #endif /* _ASM_NIOS2_PGALLOC_H */
>
> Applied!

I don't think you can just apply this patch, as the new functions
were only introduced in [PATCH v4 05/34] of this series.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v4 27/34] nios2: Convert __pte_free_tlb() to use ptdescs

[Dinh Nguyen]

On 6/14/23 04:30, Geert Uytterhoeven wrote:
> Hi Dinh,
> 
> On Wed, Jun 14, 2023 at 12:17 AM Dinh Nguyen <dinguyen@kernel.org> wrote:
>> On 6/12/23 16:04, Vishal Moola (Oracle) wrote:
>>> Part of the conversions to replace pgtable constructor/destructors with
>>> ptdesc equivalents.
>>>
>>> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
>>> ---
>>>    arch/nios2/include/asm/pgalloc.h | 8 ++++----
>>>    1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/nios2/include/asm/pgalloc.h b/arch/nios2/include/asm/pgalloc.h
>>> index ecd1657bb2ce..ce6bb8e74271 100644
>>> --- a/arch/nios2/include/asm/pgalloc.h
>>> +++ b/arch/nios2/include/asm/pgalloc.h
>>> @@ -28,10 +28,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
>>>
>>>    extern pgd_t *pgd_alloc(struct mm_struct *mm);
>>>
>>> -#define __pte_free_tlb(tlb, pte, addr)                               \
>>> -     do {                                                    \
>>> -             pgtable_pte_page_dtor(pte);                     \
>>> -             tlb_remove_page((tlb), (pte));                  \
>>> +#define __pte_free_tlb(tlb, pte, addr)                                       \
>>> +     do {                                                            \
>>> +             pagetable_pte_dtor(page_ptdesc(pte));                   \
>>> +             tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));      \
>>>        } while (0)
>>>
>>>    #endif /* _ASM_NIOS2_PGALLOC_H */
>>
>> Applied!
> 
> I don't think you can just apply this patch, as the new functions
> were only introduced in [PATCH v4 05/34] of this series.
> 

Ah, thanks for the pointer!

Dinh

Re: [PATCH v4 27/34] nios2: Convert __pte_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:16PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/nios2/include/asm/pgalloc.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/nios2/include/asm/pgalloc.h b/arch/nios2/include/asm/pgalloc.h
> index ecd1657bb2ce..ce6bb8e74271 100644
> --- a/arch/nios2/include/asm/pgalloc.h
> +++ b/arch/nios2/include/asm/pgalloc.h
> @@ -28,10 +28,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
>  
>  extern pgd_t *pgd_alloc(struct mm_struct *mm);
>  
> -#define __pte_free_tlb(tlb, pte, addr)				\
> -	do {							\
> -		pgtable_pte_page_dtor(pte);			\
> -		tlb_remove_page((tlb), (pte));			\
> +#define __pte_free_tlb(tlb, pte, addr)					\
> +	do {								\
> +		pagetable_pte_dtor(page_ptdesc(pte));			\
> +		tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>  	} while (0)
>  
>  #endif /* _ASM_NIOS2_PGALLOC_H */
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 28/34] openrisc: Convert __pte_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/openrisc/include/asm/pgalloc.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/openrisc/include/asm/pgalloc.h b/arch/openrisc/include/asm/pgalloc.h
index b7b2b8d16fad..c6a73772a546 100644
--- a/arch/openrisc/include/asm/pgalloc.h
+++ b/arch/openrisc/include/asm/pgalloc.h
@@ -66,10 +66,10 @@ extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
 
 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
 
-#define __pte_free_tlb(tlb, pte, addr)	\
-do {					\
-	pgtable_pte_page_dtor(pte);	\
-	tlb_remove_page((tlb), (pte));	\
+#define __pte_free_tlb(tlb, pte, addr)				\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
 } while (0)
 
 #endif
-- 
2.40.1

Re: [PATCH v4 28/34] openrisc: Convert __pte_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:17PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/openrisc/include/asm/pgalloc.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/openrisc/include/asm/pgalloc.h b/arch/openrisc/include/asm/pgalloc.h
> index b7b2b8d16fad..c6a73772a546 100644
> --- a/arch/openrisc/include/asm/pgalloc.h
> +++ b/arch/openrisc/include/asm/pgalloc.h
> @@ -66,10 +66,10 @@ extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
>  
>  extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
>  
> -#define __pte_free_tlb(tlb, pte, addr)	\
> -do {					\
> -	pgtable_pte_page_dtor(pte);	\
> -	tlb_remove_page((tlb), (pte));	\
> +#define __pte_free_tlb(tlb, pte, addr)				\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>  } while (0)
>  
>  #endif
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 29/34] riscv: Convert alloc_{pmd, pte}_late() to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
---
 arch/riscv/include/asm/pgalloc.h |  8 ++++----
 arch/riscv/mm/init.c             | 16 ++++++----------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 59dc12b5b7e8..d169a4f41a2e 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -153,10 +153,10 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 
 #endif /* __PAGETABLE_PMD_FOLDED */
 
-#define __pte_free_tlb(tlb, pte, buf)   \
-do {                                    \
-	pgtable_pte_page_dtor(pte);     \
-	tlb_remove_page((tlb), pte);    \
+#define __pte_free_tlb(tlb, pte, buf)			\
+do {							\
+	pagetable_pte_dtor(page_ptdesc(pte));		\
+	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));\
 } while (0)
 #endif /* CONFIG_MMU */
 
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 3d689ffb2072..6bfeec80bf4e 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -354,12 +354,10 @@ static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
 
 static phys_addr_t __init alloc_pte_late(uintptr_t va)
 {
-	unsigned long vaddr;
-
-	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page((void *)vaddr)));
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
 
-	return __pa(vaddr);
+	BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
+	return __pa((pte_t *)ptdesc_address(ptdesc));
 }
 
 static void __init create_pte_mapping(pte_t *ptep,
@@ -437,12 +435,10 @@ static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
 
 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
 {
-	unsigned long vaddr;
-
-	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page((void *)vaddr)));
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
 
-	return __pa(vaddr);
+	BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
+	return __pa((pmd_t *)ptdesc_address(ptdesc));
 }
 
 static void __init create_pmd_mapping(pmd_t *pmdp,
-- 
2.40.1

Re: [PATCH v4 29/34] riscv: Convert alloc_{pmd, pte}_late() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:18PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Some of the functions use the *get*page*() helper functions. Convert
> these to use pagetable_alloc() and ptdesc_address() instead to help
> standardize page tables further.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/riscv/include/asm/pgalloc.h |  8 ++++----
>  arch/riscv/mm/init.c             | 16 ++++++----------
>  2 files changed, 10 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> index 59dc12b5b7e8..d169a4f41a2e 100644
> --- a/arch/riscv/include/asm/pgalloc.h
> +++ b/arch/riscv/include/asm/pgalloc.h
> @@ -153,10 +153,10 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
>  
>  #endif /* __PAGETABLE_PMD_FOLDED */
>  
> -#define __pte_free_tlb(tlb, pte, buf)   \
> -do {                                    \
> -	pgtable_pte_page_dtor(pte);     \
> -	tlb_remove_page((tlb), pte);    \
> +#define __pte_free_tlb(tlb, pte, buf)			\
> +do {							\
> +	pagetable_pte_dtor(page_ptdesc(pte));		\
> +	tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));\
>  } while (0)
>  #endif /* CONFIG_MMU */
>  
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 3d689ffb2072..6bfeec80bf4e 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -354,12 +354,10 @@ static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
>  
>  static phys_addr_t __init alloc_pte_late(uintptr_t va)
>  {
> -	unsigned long vaddr;
> -
> -	vaddr = __get_free_page(GFP_KERNEL);
> -	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page((void *)vaddr)));
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	return __pa(vaddr);
> +	BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
> +	return __pa((pte_t *)ptdesc_address(ptdesc));
>  }
>  
>  static void __init create_pte_mapping(pte_t *ptep,
> @@ -437,12 +435,10 @@ static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
>  
>  static phys_addr_t __init alloc_pmd_late(uintptr_t va)
>  {
> -	unsigned long vaddr;
> -
> -	vaddr = __get_free_page(GFP_KERNEL);
> -	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page((void *)vaddr)));
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
>  
> -	return __pa(vaddr);
> +	BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
> +	return __pa((pmd_t *)ptdesc_address(ptdesc));
>  }
>  
>  static void __init create_pmd_mapping(pmd_t *pmdp,
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 30/34] sh: Convert pte_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents. Also cleans up some spacing issues.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
---
 arch/sh/include/asm/pgalloc.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/sh/include/asm/pgalloc.h b/arch/sh/include/asm/pgalloc.h
index a9e98233c4d4..5d8577ab1591 100644
--- a/arch/sh/include/asm/pgalloc.h
+++ b/arch/sh/include/asm/pgalloc.h
@@ -2,6 +2,7 @@
 #ifndef __ASM_SH_PGALLOC_H
 #define __ASM_SH_PGALLOC_H
 
+#include <linux/mm.h>
 #include <asm/page.h>
 
 #define __HAVE_ARCH_PMD_ALLOC_ONE
@@ -31,10 +32,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 	set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
 }
 
-#define __pte_free_tlb(tlb,pte,addr)			\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb), (pte));			\
+#define __pte_free_tlb(tlb, pte, addr)				\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
 } while (0)
 
 #endif /* __ASM_SH_PGALLOC_H */
-- 
2.40.1

Re: [PATCH v4 30/34] sh: Convert pte_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:19PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents. Also cleans up some spacing issues.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/sh/include/asm/pgalloc.h | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/sh/include/asm/pgalloc.h b/arch/sh/include/asm/pgalloc.h
> index a9e98233c4d4..5d8577ab1591 100644
> --- a/arch/sh/include/asm/pgalloc.h
> +++ b/arch/sh/include/asm/pgalloc.h
> @@ -2,6 +2,7 @@
>  #ifndef __ASM_SH_PGALLOC_H
>  #define __ASM_SH_PGALLOC_H
>  
> +#include <linux/mm.h>
>  #include <asm/page.h>
>  
>  #define __HAVE_ARCH_PMD_ALLOC_ONE
> @@ -31,10 +32,10 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
>  	set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
>  }
>  
> -#define __pte_free_tlb(tlb,pte,addr)			\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb), (pte));			\
> +#define __pte_free_tlb(tlb, pte, addr)				\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>  } while (0)
>  
>  #endif /* __ASM_SH_PGALLOC_H */
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 31/34] sparc64: Convert various functions to use ptdescs

[Vishal Moola (Oracle)]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/sparc/mm/init_64.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 04f9db0c3111..105915cd2eee 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -2893,14 +2893,15 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
 
 pgtable_t pte_alloc_one(struct mm_struct *mm)
 {
-	struct page *page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-	if (!page)
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL | __GFP_ZERO, 0);
+
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
-	return (pte_t *) page_address(page);
+	return ptdesc_address(ptdesc);
 }
 
 void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
@@ -2910,10 +2911,10 @@ void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 
 static void __pte_free(pgtable_t pte)
 {
-	struct page *page = virt_to_page(pte);
+	struct ptdesc *ptdesc = virt_to_ptdesc(pte);
 
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 void pte_free(struct mm_struct *mm, pgtable_t pte)
-- 
2.40.1

Re: [PATCH v4 31/34] sparc64: Convert various functions to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:20PM -0700, Vishal Moola (Oracle) wrote:
> As part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents, convert various page table functions to use ptdescs.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/sparc/mm/init_64.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
> index 04f9db0c3111..105915cd2eee 100644
> --- a/arch/sparc/mm/init_64.c
> +++ b/arch/sparc/mm/init_64.c
> @@ -2893,14 +2893,15 @@ pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
>  
>  pgtable_t pte_alloc_one(struct mm_struct *mm)
>  {
> -	struct page *page = alloc_page(GFP_KERNEL | __GFP_ZERO);
> -	if (!page)
> +	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL | __GFP_ZERO, 0);
> +
> +	if (!ptdesc)
>  		return NULL;
> -	if (!pgtable_pte_page_ctor(page)) {
> -		__free_page(page);
> +	if (!pagetable_pte_ctor(ptdesc)) {
> +		pagetable_free(ptdesc);
>  		return NULL;
>  	}
> -	return (pte_t *) page_address(page);
> +	return ptdesc_address(ptdesc);
>  }
>  
>  void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> @@ -2910,10 +2911,10 @@ void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
>  
>  static void __pte_free(pgtable_t pte)
>  {
> -	struct page *page = virt_to_page(pte);
> +	struct ptdesc *ptdesc = virt_to_ptdesc(pte);
>  
> -	pgtable_pte_page_dtor(page);
> -	__free_page(page);
> +	pagetable_pte_dtor(ptdesc);
> +	pagetable_free(ptdesc);
>  }
>  
>  void pte_free(struct mm_struct *mm, pgtable_t pte)
> -- 
> 2.40.1
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

-- 
Sincerely yours,
Mike.

[PATCH v4 32/34] sparc: Convert pgtable_pte_page_{ctor, dtor}() to ptdesc equivalents

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable pte constructor/destructors with
ptdesc equivalents.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/sparc/mm/srmmu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index 13f027afc875..8393faa3e596 100644
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -355,7 +355,8 @@ pgtable_t pte_alloc_one(struct mm_struct *mm)
 		return NULL;
 	page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT);
 	spin_lock(&mm->page_table_lock);
-	if (page_ref_inc_return(page) == 2 && !pgtable_pte_page_ctor(page)) {
+	if (page_ref_inc_return(page) == 2 &&
+			!pagetable_pte_ctor(page_ptdesc(page))) {
 		page_ref_dec(page);
 		ptep = NULL;
 	}
@@ -371,7 +372,7 @@ void pte_free(struct mm_struct *mm, pgtable_t ptep)
 	page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT);
 	spin_lock(&mm->page_table_lock);
 	if (page_ref_dec_return(page) == 1)
-		pgtable_pte_page_dtor(page);
+		pagetable_pte_dtor(page_ptdesc(page));
 	spin_unlock(&mm->page_table_lock);
 
 	srmmu_free_nocache(ptep, SRMMU_PTE_TABLE_SIZE);
-- 
2.40.1

Re: [PATCH v4 32/34] sparc: Convert pgtable_pte_page_{ctor, dtor}() to ptdesc equivalents

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:21PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable pte constructor/destructors with
> ptdesc equivalents.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/sparc/mm/srmmu.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
> index 13f027afc875..8393faa3e596 100644
> --- a/arch/sparc/mm/srmmu.c
> +++ b/arch/sparc/mm/srmmu.c
> @@ -355,7 +355,8 @@ pgtable_t pte_alloc_one(struct mm_struct *mm)
>  		return NULL;
>  	page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT);
>  	spin_lock(&mm->page_table_lock);
> -	if (page_ref_inc_return(page) == 2 && !pgtable_pte_page_ctor(page)) {
> +	if (page_ref_inc_return(page) == 2 &&
> +			!pagetable_pte_ctor(page_ptdesc(page))) {
>  		page_ref_dec(page);
>  		ptep = NULL;
>  	}
> @@ -371,7 +372,7 @@ void pte_free(struct mm_struct *mm, pgtable_t ptep)
>  	page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT);
>  	spin_lock(&mm->page_table_lock);
>  	if (page_ref_dec_return(page) == 1)
> -		pgtable_pte_page_dtor(page);
> +		pagetable_pte_dtor(page_ptdesc(page));
>  	spin_unlock(&mm->page_table_lock);
>  
>  	srmmu_free_nocache(ptep, SRMMU_PTE_TABLE_SIZE);
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 33/34] um: Convert {pmd, pte}_free_tlb() to use ptdescs

[Vishal Moola (Oracle)]

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents. Also cleans up some spacing issues.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/um/include/asm/pgalloc.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index 8ec7cd46dd96..de5e31c64793 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -25,19 +25,19 @@
  */
 extern pgd_t *pgd_alloc(struct mm_struct *);
 
-#define __pte_free_tlb(tlb,pte, address)		\
-do {							\
-	pgtable_pte_page_dtor(pte);			\
-	tlb_remove_page((tlb),(pte));			\
+#define __pte_free_tlb(tlb, pte, address)			\
+do {								\
+	pagetable_pte_dtor(page_ptdesc(pte));			\
+	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
 } while (0)
 
 #ifdef CONFIG_3_LEVEL_PGTABLES
 
-#define __pmd_free_tlb(tlb, pmd, address)		\
-do {							\
-	pgtable_pmd_page_dtor(virt_to_page(pmd));	\
-	tlb_remove_page((tlb),virt_to_page(pmd));	\
-} while (0)						\
+#define __pmd_free_tlb(tlb, pmd, address)			\
+do {								\
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));			\
+	tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd));	\
+} while (0)
 
 #endif
 
-- 
2.40.1

Re: [PATCH v4 33/34] um: Convert {pmd, pte}_free_tlb() to use ptdescs

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:22PM -0700, Vishal Moola (Oracle) wrote:
> Part of the conversions to replace pgtable constructor/destructors with
> ptdesc equivalents. Also cleans up some spacing issues.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/um/include/asm/pgalloc.h | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
> index 8ec7cd46dd96..de5e31c64793 100644
> --- a/arch/um/include/asm/pgalloc.h
> +++ b/arch/um/include/asm/pgalloc.h
> @@ -25,19 +25,19 @@
>   */
>  extern pgd_t *pgd_alloc(struct mm_struct *);
>  
> -#define __pte_free_tlb(tlb,pte, address)		\
> -do {							\
> -	pgtable_pte_page_dtor(pte);			\
> -	tlb_remove_page((tlb),(pte));			\
> +#define __pte_free_tlb(tlb, pte, address)			\
> +do {								\
> +	pagetable_pte_dtor(page_ptdesc(pte));			\
> +	tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte)));	\
>  } while (0)
>  
>  #ifdef CONFIG_3_LEVEL_PGTABLES
>  
> -#define __pmd_free_tlb(tlb, pmd, address)		\
> -do {							\
> -	pgtable_pmd_page_dtor(virt_to_page(pmd));	\
> -	tlb_remove_page((tlb),virt_to_page(pmd));	\
> -} while (0)						\
> +#define __pmd_free_tlb(tlb, pmd, address)			\
> +do {								\
> +	pagetable_pmd_dtor(virt_to_ptdesc(pmd));			\
> +	tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd));	\
> +} while (0)
>  
>  #endif
>  
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.

[PATCH v4 34/34] mm: Remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers

[Vishal Moola (Oracle)]

These functions are no longer necessary. Remove them and cleanup
Documentation referencing them.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 Documentation/mm/split_page_table_lock.rst    | 12 +++++------
 .../zh_CN/mm/split_page_table_lock.rst        | 14 ++++++-------
 include/linux/mm.h                            | 20 -------------------
 3 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/Documentation/mm/split_page_table_lock.rst b/Documentation/mm/split_page_table_lock.rst
index 50ee0dfc95be..4bffec728340 100644
--- a/Documentation/mm/split_page_table_lock.rst
+++ b/Documentation/mm/split_page_table_lock.rst
@@ -53,7 +53,7 @@ Support of split page table lock by an architecture
 ===================================================
 
 There's no need in special enabling of PTE split page table lock: everything
-required is done by pgtable_pte_page_ctor() and pgtable_pte_page_dtor(), which
+required is done by pagetable_pte_ctor() and pagetable_pte_dtor(), which
 must be called on PTE table allocation / freeing.
 
 Make sure the architecture doesn't use slab allocator for page table
@@ -63,8 +63,8 @@ This field shares storage with page->ptl.
 PMD split lock only makes sense if you have more than two page table
 levels.
 
-PMD split lock enabling requires pgtable_pmd_page_ctor() call on PMD table
-allocation and pgtable_pmd_page_dtor() on freeing.
+PMD split lock enabling requires pagetable_pmd_ctor() call on PMD table
+allocation and pagetable_pmd_dtor() on freeing.
 
 Allocation usually happens in pmd_alloc_one(), freeing in pmd_free() and
 pmd_free_tlb(), but make sure you cover all PMD table allocation / freeing
@@ -72,7 +72,7 @@ paths: i.e X86_PAE preallocate few PMDs on pgd_alloc().
 
 With everything in place you can set CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK.
 
-NOTE: pgtable_pte_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must
+NOTE: pagetable_pte_ctor() and pagetable_pmd_ctor() can fail -- it must
 be handled properly.
 
 page->ptl
@@ -92,7 +92,7 @@ trick:
    split lock with enabled DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC, but costs
    one more cache line for indirect access;
 
-The spinlock_t allocated in pgtable_pte_page_ctor() for PTE table and in
-pgtable_pmd_page_ctor() for PMD table.
+The spinlock_t allocated in pagetable_pte_ctor() for PTE table and in
+pagetable_pmd_ctor() for PMD table.
 
 Please, never access page->ptl directly -- use appropriate helper.
diff --git a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
index 4fb7aa666037..a2c288670a24 100644
--- a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
+++ b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
@@ -56,16 +56,16 @@ Hugetlb特定的辅助函数:
 架构对分页表锁的支持
 ====================
 
-没有必要特别启用PTE分页表锁：所有需要的东西都由pgtable_pte_page_ctor()
-和pgtable_pte_page_dtor()完成，它们必须在PTE表分配/释放时被调用。
+没有必要特别启用PTE分页表锁：所有需要的东西都由pagetable_pte_ctor()
+和pagetable_pte_dtor()完成，它们必须在PTE表分配/释放时被调用。
 
 确保架构不使用slab分配器来分配页表：slab使用page->slab_cache来分配其页
 面。这个区域与page->ptl共享存储。
 
 PMD分页锁只有在你有两个以上的页表级别时才有意义。
 
-启用PMD分页锁需要在PMD表分配时调用pgtable_pmd_page_ctor()，在释放时调
-用pgtable_pmd_page_dtor()。
+启用PMD分页锁需要在PMD表分配时调用pagetable_pmd_ctor()，在释放时调
+用pagetable_pmd_dtor()。
 
 分配通常发生在pmd_alloc_one()中，释放发生在pmd_free()和pmd_free_tlb()
 中，但要确保覆盖所有的PMD表分配/释放路径：即X86_PAE在pgd_alloc()中预先
@@ -73,7 +73,7 @@ PMD分页锁只有在你有两个以上的页表级别时才有意义。
 
 一切就绪后，你可以设置CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK。
 
-注意：pgtable_pte_page_ctor()和pgtable_pmd_page_ctor()可能失败--必
+注意：pagetable_pte_ctor()和pagetable_pmd_ctor()可能失败--必
 须正确处理。
 
 page->ptl
@@ -90,7 +90,7 @@ page->ptl用于访问分割页表锁，其中'page'是包含该表的页面struc
    的指针并动态分配它。这允许在启用DEBUG_SPINLOCK或DEBUG_LOCK_ALLOC的
    情况下使用分页锁，但由于间接访问而多花了一个缓存行。
 
-PTE表的spinlock_t分配在pgtable_pte_page_ctor()中，PMD表的spinlock_t
-分配在pgtable_pmd_page_ctor()中。
+PTE表的spinlock_t分配在pagetable_pte_ctor()中，PMD表的spinlock_t
+分配在pagetable_pmd_ctor()中。
 
 请不要直接访问page->ptl - -使用适当的辅助函数。
diff --git a/include/linux/mm.h b/include/linux/mm.h
index dc211c43610b..6d83483cf186 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2897,11 +2897,6 @@ static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc)
 	return true;
 }
 
-static inline bool pgtable_pte_page_ctor(struct page *page)
-{
-	return pagetable_pte_ctor(page_ptdesc(page));
-}
-
 static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
 {
 	struct folio *folio = ptdesc_folio(ptdesc);
@@ -2911,11 +2906,6 @@ static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
 	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
 }
 
-static inline void pgtable_pte_page_dtor(struct page *page)
-{
-	pagetable_pte_dtor(page_ptdesc(page));
-}
-
 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
 ({							\
 	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
@@ -3006,11 +2996,6 @@ static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc)
 	return true;
 }
 
-static inline bool pgtable_pmd_page_ctor(struct page *page)
-{
-	return pagetable_pmd_ctor(page_ptdesc(page));
-}
-
 static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
 {
 	struct folio *folio = ptdesc_folio(ptdesc);
@@ -3020,11 +3005,6 @@ static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
 	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
 }
 
-static inline void pgtable_pmd_page_dtor(struct page *page)
-{
-	pagetable_pmd_dtor(page_ptdesc(page));
-}
-
 /*
  * No scalability reason to split PUD locks yet, but follow the same pattern
  * as the PMD locks to make it easier if we decide to.  The VM should not be
-- 
2.40.1

Re: [PATCH v4 34/34] mm: Remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers

[Mike Rapoport]

On Mon, Jun 12, 2023 at 02:04:23PM -0700, Vishal Moola (Oracle) wrote:
> These functions are no longer necessary. Remove them and cleanup
> Documentation referencing them.
> 
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>

I've found one stale reference in riscv:

$ git grep -n pgtable_pmd_page_ctor
arch/riscv/mm/init.c:440:       BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));

Otherwise

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>


> ---
>  Documentation/mm/split_page_table_lock.rst    | 12 +++++------
>  .../zh_CN/mm/split_page_table_lock.rst        | 14 ++++++-------
>  include/linux/mm.h                            | 20 -------------------
>  3 files changed, 13 insertions(+), 33 deletions(-)
> 
> diff --git a/Documentation/mm/split_page_table_lock.rst b/Documentation/mm/split_page_table_lock.rst
> index 50ee0dfc95be..4bffec728340 100644
> --- a/Documentation/mm/split_page_table_lock.rst
> +++ b/Documentation/mm/split_page_table_lock.rst
> @@ -53,7 +53,7 @@ Support of split page table lock by an architecture
>  ===================================================
>  
>  There's no need in special enabling of PTE split page table lock: everything
> -required is done by pgtable_pte_page_ctor() and pgtable_pte_page_dtor(), which
> +required is done by pagetable_pte_ctor() and pagetable_pte_dtor(), which
>  must be called on PTE table allocation / freeing.
>  
>  Make sure the architecture doesn't use slab allocator for page table
> @@ -63,8 +63,8 @@ This field shares storage with page->ptl.
>  PMD split lock only makes sense if you have more than two page table
>  levels.
>  
> -PMD split lock enabling requires pgtable_pmd_page_ctor() call on PMD table
> -allocation and pgtable_pmd_page_dtor() on freeing.
> +PMD split lock enabling requires pagetable_pmd_ctor() call on PMD table
> +allocation and pagetable_pmd_dtor() on freeing.
>  
>  Allocation usually happens in pmd_alloc_one(), freeing in pmd_free() and
>  pmd_free_tlb(), but make sure you cover all PMD table allocation / freeing
> @@ -72,7 +72,7 @@ paths: i.e X86_PAE preallocate few PMDs on pgd_alloc().
>  
>  With everything in place you can set CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK.
>  
> -NOTE: pgtable_pte_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must
> +NOTE: pagetable_pte_ctor() and pagetable_pmd_ctor() can fail -- it must
>  be handled properly.
>  
>  page->ptl
> @@ -92,7 +92,7 @@ trick:
>     split lock with enabled DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC, but costs
>     one more cache line for indirect access;
>  
> -The spinlock_t allocated in pgtable_pte_page_ctor() for PTE table and in
> -pgtable_pmd_page_ctor() for PMD table.
> +The spinlock_t allocated in pagetable_pte_ctor() for PTE table and in
> +pagetable_pmd_ctor() for PMD table.
>  
>  Please, never access page->ptl directly -- use appropriate helper.
> diff --git a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
> index 4fb7aa666037..a2c288670a24 100644
> --- a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
> +++ b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
> @@ -56,16 +56,16 @@ Hugetlb特定的辅助函数:
>  架构对分页表锁的支持
>  ====================
>  
> -没有必要特别启用PTE分页表锁：所有需要的东西都由pgtable_pte_page_ctor()
> -和pgtable_pte_page_dtor()完成，它们必须在PTE表分配/释放时被调用。
> +没有必要特别启用PTE分页表锁：所有需要的东西都由pagetable_pte_ctor()
> +和pagetable_pte_dtor()完成，它们必须在PTE表分配/释放时被调用。
>  
>  确保架构不使用slab分配器来分配页表：slab使用page->slab_cache来分配其页
>  面。这个区域与page->ptl共享存储。
>  
>  PMD分页锁只有在你有两个以上的页表级别时才有意义。
>  
> -启用PMD分页锁需要在PMD表分配时调用pgtable_pmd_page_ctor()，在释放时调
> -用pgtable_pmd_page_dtor()。
> +启用PMD分页锁需要在PMD表分配时调用pagetable_pmd_ctor()，在释放时调
> +用pagetable_pmd_dtor()。
>  
>  分配通常发生在pmd_alloc_one()中，释放发生在pmd_free()和pmd_free_tlb()
>  中，但要确保覆盖所有的PMD表分配/释放路径：即X86_PAE在pgd_alloc()中预先
> @@ -73,7 +73,7 @@ PMD分页锁只有在你有两个以上的页表级别时才有意义。
>  
>  一切就绪后，你可以设置CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK。
>  
> -注意：pgtable_pte_page_ctor()和pgtable_pmd_page_ctor()可能失败--必
> +注意：pagetable_pte_ctor()和pagetable_pmd_ctor()可能失败--必
>  须正确处理。
>  
>  page->ptl
> @@ -90,7 +90,7 @@ page->ptl用于访问分割页表锁，其中'page'是包含该表的页面struc
>     的指针并动态分配它。这允许在启用DEBUG_SPINLOCK或DEBUG_LOCK_ALLOC的
>     情况下使用分页锁，但由于间接访问而多花了一个缓存行。
>  
> -PTE表的spinlock_t分配在pgtable_pte_page_ctor()中，PMD表的spinlock_t
> -分配在pgtable_pmd_page_ctor()中。
> +PTE表的spinlock_t分配在pagetable_pte_ctor()中，PMD表的spinlock_t
> +分配在pagetable_pmd_ctor()中。
>  
>  请不要直接访问page->ptl - -使用适当的辅助函数。
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index dc211c43610b..6d83483cf186 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2897,11 +2897,6 @@ static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc)
>  	return true;
>  }
>  
> -static inline bool pgtable_pte_page_ctor(struct page *page)
> -{
> -	return pagetable_pte_ctor(page_ptdesc(page));
> -}
> -
>  static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
>  {
>  	struct folio *folio = ptdesc_folio(ptdesc);
> @@ -2911,11 +2906,6 @@ static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)
>  	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
>  }
>  
> -static inline void pgtable_pte_page_dtor(struct page *page)
> -{
> -	pagetable_pte_dtor(page_ptdesc(page));
> -}
> -
>  #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
>  ({							\
>  	spinlock_t *__ptl = pte_lockptr(mm, pmd);	\
> @@ -3006,11 +2996,6 @@ static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc)
>  	return true;
>  }
>  
> -static inline bool pgtable_pmd_page_ctor(struct page *page)
> -{
> -	return pagetable_pmd_ctor(page_ptdesc(page));
> -}
> -
>  static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
>  {
>  	struct folio *folio = ptdesc_folio(ptdesc);
> @@ -3020,11 +3005,6 @@ static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)
>  	lruvec_stat_sub_folio(folio, NR_PAGETABLE);
>  }
>  
> -static inline void pgtable_pmd_page_dtor(struct page *page)
> -{
> -	pagetable_pmd_dtor(page_ptdesc(page));
> -}
> -
>  /*
>   * No scalability reason to split PUD locks yet, but follow the same pattern
>   * as the PMD locks to make it easier if we decide to.  The VM should not be
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.