[RFC v2 PATCH 02/17] mm: pass gfp flags and order to vma_alloc_zeroed_movable_folio()

Ryan Roberts
2023-04-14T14:16:43Z

Allow allocation of large folios with vma_alloc_zeroed_movable_folio().
This prepares the ground for large anonymous folios. The generic
implementation of vma_alloc_zeroed_movable_folio() now uses
clear_huge_page() to zero the allocated folio since it may now be a
non-0 order.

Currently the function is always called with order 0 and no extra gfp
flags, so no functional change intended.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
arch/alpha/include/asm/page.h | 5 +++--
arch/arm64/include/asm/page.h | 3 ++-
arch/arm64/mm/fault.c | 7 ++++---
arch/ia64/include/asm/page.h | 5 +++--
arch/m68k/include/asm/page_no.h | 7 ++++---
arch/s390/include/asm/page.h | 5 +++--
arch/x86/include/asm/page.h | 5 +++--
include/linux/highmem.h | 23 +++++++++++++----------
mm/memory.c | 5 +++--
9 files changed, 38 insertions(+), 27 deletions(-)

diff --git a/arch/alpha/include/asm/page.h b/arch/alpha/include/asm/page.h
index 4db1ebc0ed99..6fc7fe91b6cb 100644
--- a/arch/alpha/include/asm/page.h
+++ b/arch/alpha/include/asm/page.h
@@ -17,8 +17,9 @@
extern void clear_page(void *page);
#define clear_user_page(page, vaddr, pg) clear_page(page)

-#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
- vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr, false)
+#define vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order) \
+ vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO | (gfp), \
+ order, vma, vaddr, false)

extern void copy_page(void * _to, void * _from);
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index 2312e6ee595f..47710852f872 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -30,7 +30,8 @@ void copy_highpage(struct page *to, struct page *from);
#define __HAVE_ARCH_COPY_HIGHPAGE

struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
- unsigned long vaddr);
+ unsigned long vaddr,
+ gfp_t gfp, int order);
#define vma_alloc_zeroed_movable_folio vma_alloc_zeroed_movable_folio

void tag_clear_highpage(struct page *to);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index f4cb0f85ccf4..3b4cc04f7a23 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -926,9 +926,10 @@ NOKPROBE_SYMBOL(do_debug_exception);
* Used during anonymous page fault handling.
*/
struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
- unsigned long vaddr)
+ unsigned long vaddr,
+ gfp_t gfp, int order)
{
- gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO;
+ gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO | gfp;

/*
* If the page is mapped with PROT_MTE, initialise the tags at the
@@ -938,7 +939,7 @@ struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
if (vma->vm_flags & VM_MTE)
flags |= __GFP_ZEROTAGS;

- return vma_alloc_folio(flags, 0, vma, vaddr, false);
+ return vma_alloc_folio(flags, order, vma, vaddr, false);
}

void tag_clear_highpage(struct page *page)
diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h
index 310b09c3342d..ebdf04274023 100644
--- a/arch/ia64/include/asm/page.h
+++ b/arch/ia64/include/asm/page.h
@@ -82,10 +82,11 @@ do { \
} while (0)

-#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
+#define vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order) \
({ \
struct folio *folio = vma_alloc_folio( \
- GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr, false); \
+ GFP_HIGHUSER_MOVABLE | __GFP_ZERO | (gfp), \
+ order, vma, vaddr, false); \
if (folio) \
flush_dcache_folio(folio); \
folio; \
diff --git a/arch/m68k/include/asm/page_no.h b/arch/m68k/include/asm/page_no.h
index 060e4c0e7605..4a2fe57fef5e 100644
--- a/arch/m68k/include/asm/page_no.h
+++ b/arch/m68k/include/asm/page_no.h
@@ -3,7 +3,7 @@
#define _M68K_PAGE_NO_H

#ifndef __ASSEMBLY__
-
+
extern unsigned long memory_start;
extern unsigned long memory_end;

@@ -13,8 +13,9 @@ extern unsigned long memory_end;
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)

-#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
- vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr, false)
+#define vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order) \
+ vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO | (gfp), \
+ order, vma, vaddr, false)

#define __pa(vaddr) ((unsigned long)(vaddr))
#define __va(paddr) ((void *)((unsigned long)(paddr)))
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 8a2a3b5d1e29..b749564140f1 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -73,8 +73,9 @@ static inline void copy_page(void *to, void *from)
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)

-#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
- vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr, false)
+#define vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order) \
+ vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO | (gfp), \
+ order, vma, vaddr, false)

/*
* These are used to make use of C type-checking..
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index d18e5c332cb9..34deab1a8dae 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -34,8 +34,9 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
copy_page(to, from);
}

-#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
- vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr, false)
+#define vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order) \
+ vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO | (gfp), \
+ order, vma, vaddr, false)

#ifndef __pa
#define __pa(x) __phys_addr((unsigned long)(x))
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 8fc10089e19e..54e68deae5ef 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -209,26 +209,29 @@ static inline void clear_user_highpage(struct page *page, unsigned long vaddr)

#ifndef vma_alloc_zeroed_movable_folio
/**
- * vma_alloc_zeroed_movable_folio - Allocate a zeroed page for a VMA.
- * @vma: The VMA the page is to be allocated for.
- * @vaddr: The virtual address the page will be inserted into.
- *
- * This function will allocate a page suitable for inserting into this
- * VMA at this virtual address. It may be allocated from highmem or
+ * vma_alloc_zeroed_movable_folio - Allocate a zeroed folio for a VMA.
+ * @vma: The start VMA the folio is to be allocated for.
+ * @vaddr: The virtual address the folio will be inserted into.
+ * @gfp: Additional gfp falgs to mix in or 0.
+ * @order: The order of the folio (2^order pages).
+ *
+ * This function will allocate a folio suitable for inserting into this
+ * VMA starting at this virtual address. It may be allocated from highmem or
* the movable zone. An architecture may provide its own implementation.
*
- * Return: A folio containing one allocated and zeroed page or NULL if
+ * Return: A folio containing 2^order allocated and zeroed pages or NULL if
* we are out of memory.
*/
static inline
struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
- unsigned long vaddr)
+ unsigned long vaddr, gfp_t gfp, int order)
{
struct folio *folio;

- folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, vaddr, false);
+ folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE | gfp,
+ order, vma, vaddr, false);
if (folio)
- clear_user_highpage(&folio->page, vaddr);
+ clear_huge_page(&folio->page, vaddr, 1U << order);

return folio;
}
diff --git a/mm/memory.c b/mm/memory.c
index 3e2eee8c66a7..9d5e8be49f3b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3061,7 +3061,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
goto oom;

if (is_zero_pfn(pte_pfn(vmf->orig_pte))) {
- new_folio = vma_alloc_zeroed_movable_folio(vma, vmf->address);
+ new_folio = vma_alloc_zeroed_movable_folio(vma, vmf->address,
+ 0, 0);
if (!new_folio)
goto oom;
} else {
@@ -4063,7 +4064,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
/* Allocate our own private page. */
if (unlikely(anon_vma_prepare(vma)))
goto oom;
- folio = vma_alloc_zeroed_movable_folio(vma, vmf->address);
+ folio = vma_alloc_zeroed_movable_folio(vma, vmf->address, 0, 0);
if (!folio)
goto oom;

--
2.25.1