[PATCH v2 08/13] parisc: use pgtable-nopXd instead of 4level-fixup

Mike Rapoport
2019-11-01T08:41:19Z

parisc has two or three levels of page tables and can use appropriate
pgtable-nopXd and folding of the upper layers.

Replace usage of include/asm-generic/4level-fixup.h and explicit
definitions of __PAGETABLE_PxD_FOLDED in parisc with
include/asm-generic/pgtable-nopmd.h for two-level configurations and with
include/asm-generic/pgtable-nopud.h for three-lelve configurations and
adjust page table manipulation macros and functions accordingly.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
---
arch/parisc/include/asm/page.h | 30 +++++++++++++---------
arch/parisc/include/asm/pgalloc.h | 41 +++++++++++-------------------
arch/parisc/include/asm/pgtable.h | 52 +++++++++++++++++++--------------------
arch/parisc/include/asm/tlb.h | 2 ++
arch/parisc/kernel/cache.c | 13 ++++++----
arch/parisc/kernel/pci-dma.c | 9 +++++--
arch/parisc/mm/fixmap.c | 10 +++++---
7 files changed, 81 insertions(+), 76 deletions(-)

diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index 93caf17..796ae29 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -42,48 +42,54 @@ typedef struct { unsigned long pte; } pte_t; /* either 32 or 64bit */

/* NOTE: even on 64 bits, these entries are __u32 because we allocate
* the pmd and pgd in ZONE_DMA (i.e. under 4GB) */
-typedef struct { __u32 pmd; } pmd_t;
typedef struct { __u32 pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;

-#define pte_val(x) ((x).pte)
-/* These do not work lvalues, so make sure we don't use them as such. */
+#if CONFIG_PGTABLE_LEVELS == 3
+typedef struct { __u32 pmd; } pmd_t;
+#define __pmd(x) ((pmd_t) { (x) } )
+/* pXd_val() do not work as lvalues, so make sure we don't use them as such. */
#define pmd_val(x) ((x).pmd + 0)
+#endif
+
+#define pte_val(x) ((x).pte)
#define pgd_val(x) ((x).pgd + 0)
#define pgprot_val(x) ((x).pgprot)

#define __pte(x) ((pte_t) { (x) } )
-#define __pmd(x) ((pmd_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )

-#define __pmd_val_set(x,n) (x).pmd = (n)
-#define __pgd_val_set(x,n) (x).pgd = (n)
-
#else
/*
* .. while these make it easier on the compiler
*/
typedef unsigned long pte_t;
+
+#if CONFIG_PGTABLE_LEVELS == 3
typedef __u32 pmd_t;
+#define pmd_val(x) (x)
+#define __pmd(x) (x)
+#endif
+
typedef __u32 pgd_t;
typedef unsigned long pgprot_t;

#define pte_val(x) (x)
-#define pmd_val(x) (x)
#define pgd_val(x) (x)
#define pgprot_val(x) (x)

#define __pte(x) (x)
-#define __pmd(x) (x)
#define __pgd(x) (x)
#define __pgprot(x) (x)

-#define __pmd_val_set(x,n) (x) = (n)
-#define __pgd_val_set(x,n) (x) = (n)
-
#endif /* STRICT_MM_TYPECHECKS */

+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+#if CONFIG_PGTABLE_LEVELS == 3
+#define set_pud(pudptr, pudval) (*(pudptr) = (pudval))
+#endif
+
typedef struct page *pgtable_t;

typedef struct __physmem_range {
diff --git a/arch/parisc/include/asm/pgalloc.h b/arch/parisc/include/asm/pgalloc.h
index d98647c..9ac74da 100644
--- a/arch/parisc/include/asm/pgalloc.h
+++ b/arch/parisc/include/asm/pgalloc.h
@@ -34,13 +34,13 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
/* Populate first pmd with allocated memory. We mark it
* with PxD_FLAG_ATTACHED as a signal to the system that this
* pmd entry may not be cleared. */
- __pgd_val_set(*actual_pgd, (PxD_FLAG_PRESENT |
- PxD_FLAG_VALID |
- PxD_FLAG_ATTACHED)
- + (__u32)(__pa((unsigned long)pgd) >> PxD_VALUE_SHIFT));
+ set_pgd(actual_pgd, __pgd((PxD_FLAG_PRESENT |
+ PxD_FLAG_VALID |
+ PxD_FLAG_ATTACHED)
+ + (__u32)(__pa((unsigned long)pgd) >> PxD_VALUE_SHIFT)));
/* The first pmd entry also is marked with PxD_FLAG_ATTACHED as
* a signal that this pmd may not be freed */
- __pgd_val_set(*pgd, PxD_FLAG_ATTACHED);
+ set_pgd(pgd, __pgd(PxD_FLAG_ATTACHED));
#endif
}
spin_lock_init(pgd_spinlock(actual_pgd));
@@ -59,10 +59,10 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)

/* Three Level Page Table Support for pmd's */

-static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
+static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
- __pgd_val_set(*pgd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID) +
- (__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT));
+ set_pud(pud, __pud((PxD_FLAG_PRESENT | PxD_FLAG_VALID) +
+ (__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT)));
}

static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
@@ -88,19 +88,6 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
free_pages((unsigned long)pmd, PMD_ORDER);
}

-#else
-
-/* Two Level Page Table Support for pmd's */
-
-/*
- * allocating and freeing a pmd is trivial: the 1-entry pmd is
- * inside the pgd, so has no extra memory associated with it.
- */
-
-#define pmd_alloc_one(mm, addr) ({ BUG(); ((pmd_t *)2); })
-#define pmd_free(mm, x) do { } while (0)
-#define pgd_populate(mm, pmd, pte) BUG()
-
#endif

static inline void
@@ -110,14 +97,14 @@ pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
/* preserve the gateway marker if this is the beginning of
* the permanent pmd */
if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
- __pmd_val_set(*pmd, (PxD_FLAG_PRESENT |
- PxD_FLAG_VALID |
- PxD_FLAG_ATTACHED)
- + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT));
+ set_pmd(pmd, __pmd((PxD_FLAG_PRESENT |
+ PxD_FLAG_VALID |
+ PxD_FLAG_ATTACHED)
+ + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)));
else
#endif
- __pmd_val_set(*pmd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID)
- + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT));
+ set_pmd(pmd, __pmd((PxD_FLAG_PRESENT | PxD_FLAG_VALID)
+ + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)));
}

#define pmd_populate(mm, pmd, pte_page) \
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index 4ac374b..f0a3659 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -3,7 +3,12 @@
#define _PARISC_PGTABLE_H

#include <asm/page.h>
-#include <asm-generic/4level-fixup.h>
+
+#if CONFIG_PGTABLE_LEVELS == 3
+#include <asm-generic/pgtable-nopud.h>
+#elif CONFIG_PGTABLE_LEVELS == 2
+#include <asm-generic/pgtable-nopmd.h>
+#endif

#include <asm/fixmap.h>

@@ -101,8 +106,10 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)

#define pte_ERROR(e) \
printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#if CONFIG_PGTABLE_LEVELS == 3
#define pmd_ERROR(e) \
printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
+#endif
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))

@@ -132,19 +139,18 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
#define PTRS_PER_PTE (1UL << BITS_PER_PTE)

/* Definitions for 2nd level */
+#if CONFIG_PGTABLE_LEVELS == 3
#define PMD_SHIFT (PLD_SHIFT + BITS_PER_PTE)
#define PMD_SIZE (1UL << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
-#if CONFIG_PGTABLE_LEVELS == 3
#define BITS_PER_PMD (PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
+#define PTRS_PER_PMD (1UL << BITS_PER_PMD)
#else
-#define __PAGETABLE_PMD_FOLDED 1
#define BITS_PER_PMD 0
#endif
-#define PTRS_PER_PMD (1UL << BITS_PER_PMD)

/* Definitions for 1st level */
-#define PGDIR_SHIFT (PMD_SHIFT + BITS_PER_PMD)
+#define PGDIR_SHIFT (PLD_SHIFT + BITS_PER_PTE + BITS_PER_PMD)
#if (PGDIR_SHIFT + PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
#define BITS_PER_PGD (BITS_PER_LONG - PGDIR_SHIFT)
#else
@@ -317,6 +323,8 @@ extern unsigned long *empty_zero_page;

#define pmd_flag(x) (pmd_val(x) & PxD_FLAG_MASK)
#define pmd_address(x) ((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
+#define pud_flag(x) (pud_val(x) & PxD_FLAG_MASK)
+#define pud_address(x) ((unsigned long)(pud_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
#define pgd_flag(x) (pgd_val(x) & PxD_FLAG_MASK)
#define pgd_address(x) ((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)

@@ -334,42 +342,32 @@ static inline void pmd_clear(pmd_t *pmd) {
if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
/* This is the entry pointing to the permanent pmd
* attached to the pgd; cannot clear it */
- __pmd_val_set(*pmd, PxD_FLAG_ATTACHED);
+ set_pmd(pmd, __pmd(PxD_FLAG_ATTACHED));
else
#endif
- __pmd_val_set(*pmd, 0);
+ set_pmd(pmd, __pmd(0));
}

#if CONFIG_PGTABLE_LEVELS == 3
-#define pgd_page_vaddr(pgd) ((unsigned long) __va(pgd_address(pgd)))
-#define pgd_page(pgd) virt_to_page((void *)pgd_page_vaddr(pgd))
+#define pud_page_vaddr(pud) ((unsigned long) __va(pud_address(pud)))
+#define pud_page(pud) virt_to_page((void *)pud_page_vaddr(pud))

/* For 64 bit we have three level tables */

-#define pgd_none(x) (!pgd_val(x))
-#define pgd_bad(x) (!(pgd_flag(x) & PxD_FLAG_VALID))
-#define pgd_present(x) (pgd_flag(x) & PxD_FLAG_PRESENT)
-static inline void pgd_clear(pgd_t *pgd) {
+#define pud_none(x) (!pud_val(x))
+#define pud_bad(x) (!(pud_flag(x) & PxD_FLAG_VALID))
+#define pud_present(x) (pud_flag(x) & PxD_FLAG_PRESENT)
+static inline void pud_clear(pud_t *pud) {
#if CONFIG_PGTABLE_LEVELS == 3
- if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
- /* This is the permanent pmd attached to the pgd; cannot
+ if(pud_flag(*pud) & PxD_FLAG_ATTACHED)
+ /* This is the permanent pmd attached to the pud; cannot
* free it */
return;
#endif
- __pgd_val_set(*pgd, 0);
+ set_pud(pud, __pud(0));
}
-#else
-/*
- * The "pgd_xxx()" functions here are trivial for a folded two-level
- * setup: the pgd is never bad, and a pmd always exists (as it's folded
- * into the pgd entry)
- */
-static inline int pgd_none(pgd_t pgd) { return 0; }
-static inline int pgd_bad(pgd_t pgd) { return 0; }
-static inline int pgd_present(pgd_t pgd) { return 1; }
-static inline void pgd_clear(pgd_t * pgdp) { }
#endif

/*
@@ -452,7 +450,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#if CONFIG_PGTABLE_LEVELS == 3
#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
#define pmd_offset(dir,address) \
-((pmd_t *) pgd_page_vaddr(*(dir)) + pmd_index(address))
+((pmd_t *) pud_page_vaddr(*(dir)) + pmd_index(address))
#else
#define pmd_offset(dir,addr) ((pmd_t *) dir)
#endif
diff --git a/arch/parisc/include/asm/tlb.h b/arch/parisc/include/asm/tlb.h
index 8c0446b..44235f3 100644
--- a/arch/parisc/include/asm/tlb.h
+++ b/arch/parisc/include/asm/tlb.h
@@ -4,7 +4,9 @@

#include <asm-generic/tlb.h>

+#if CONFIG_PGTABLE_LEVELS == 3
#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
+#endif
#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)

#endif
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index a82b3ea..7b2e0ab 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -534,11 +534,14 @@ static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr)
pte_t *ptep = NULL;

if (!pgd_none(*pgd)) {
- pud_t *pud = pud_offset(pgd, addr);
- if (!pud_none(*pud)) {
- pmd_t *pmd = pmd_offset(pud, addr);
- if (!pmd_none(*pmd))
- ptep = pte_offset_map(pmd, addr);
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ if (!p4d_none(*p4d)) {
+ pud_t *pud = pud_offset(p4d, addr);
+ if (!pud_none(*pud)) {
+ pmd_t *pmd = pmd_offset(pud, addr);
+ if (!pmd_none(*pmd))
+ ptep = pte_offset_map(pmd, addr);
+ }
}
}
return ptep;
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index ca35d9a..8859c71 100644
--- a/arch/parisc/kernel/pci-dma.c
+++ b/arch/parisc/kernel/pci-dma.c
@@ -133,9 +133,14 @@ static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,

dir = pgd_offset_k(vaddr);
do {
+ p4d_t *p4d;
+ pud_t *pud;
pmd_t *pmd;
-
- pmd = pmd_alloc(NULL, dir, vaddr);
+
+ p4d = p4d_offset(dir, vaddr);
+ pud = pud_offset(p4d, vaddr);
+ pmd = pmd_alloc(NULL, pud, vaddr);
+
if (!pmd)
return -ENOMEM;
if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
diff --git a/arch/parisc/mm/fixmap.c b/arch/parisc/mm/fixmap.c
index 474cd24..e2d8b0a 100644
--- a/arch/parisc/mm/fixmap.c
+++ b/arch/parisc/mm/fixmap.c
@@ -14,11 +14,13 @@ void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
{
unsigned long vaddr = __fix_to_virt(idx);
pgd_t *pgd = pgd_offset_k(vaddr);
- pmd_t *pmd = pmd_offset(pgd, vaddr);
+ p4d_t *p4d = p4d_offset(pgd, vaddr);
+ pud_t *pud = pud_offset(p4d, vaddr);
+ pmd_t *pmd = pmd_offset(pud, vaddr);
pte_t *pte;

if (pmd_none(*pmd))
- pmd = pmd_alloc(NULL, pgd, vaddr);
+ pmd = pmd_alloc(NULL, pud, vaddr);

pte = pte_offset_kernel(pmd, vaddr);
if (pte_none(*pte))
@@ -32,7 +34,9 @@ void notrace clear_fixmap(enum fixed_addresses idx)
{
unsigned long vaddr = __fix_to_virt(idx);
pgd_t *pgd = pgd_offset_k(vaddr);
- pmd_t *pmd = pmd_offset(pgd, vaddr);
+ p4d_t *p4d = p4d_offset(pgd, vaddr);
+ pud_t *pud = pud_offset(p4d, vaddr);
+ pmd_t *pmd = pmd_offset(pud, vaddr);
pte_t *pte = pte_offset_kernel(pmd, vaddr);

if (WARN_ON(pte_none(*pte)))
--
2.7.4