Thread (20 messages) 20 messages, 5 authors, 2020-07-02
STALE2161d

[PATCH 4/8] asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()

From: Mike Rapoport <rppt@kernel.org>
Date: 2020-06-27 14:35:46
Also in: linux-alpha, linux-arch, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linux-um, linuxppc-dev, lkml, sparclinux
Subsystem: alpha port, arm port, arm64 port (aarch64 architecture), generic include/asm header files, mips, parisc architecture, risc-v architecture, superh, the rest, user-mode linux (uml), x86 architecture (32-bit and 64-bit) · Maintainers: Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Catalin Marinas, Will Deacon, Arnd Bergmann, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, Paul Walmsley, Palmer Dabbelt, Albert Ou, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds, Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

From: Mike Rapoport <redacted>

For most architectures that support >2 levels of page tables,
pmd_alloc_one() is a wrapper for __get_free_pages(), sometimes with
__GFP_ZERO and sometimes followed by memset(0) instead.

More elaborate versions on arm64 and x86 account memory for the user page
tables and call to pgtable_pmd_page_ctor() as the part of PMD page
initialization.

Move the arm64 version to include/asm-generic/pgalloc.h and use the generic
version on several architectures.

The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is
not enabled, so there is no functional change for most architectures except
of the addition of __GFP_ACCOUNT for allocation of user page tables.

The pmd_free() is a wrapper for free_page() in all the cases, so no
functional change here.

Signed-off-by: Mike Rapoport <redacted>
---
 arch/alpha/include/asm/pgalloc.h     | 15 +---------
 arch/arm/include/asm/pgalloc.h       | 11 -------
 arch/arm64/include/asm/pgalloc.h     | 27 +----------------
 arch/ia64/include/asm/pgalloc.h      | 10 -------
 arch/mips/include/asm/pgalloc.h      |  8 ++----
 arch/parisc/include/asm/pgalloc.h    | 11 ++-----
 arch/riscv/include/asm/pgalloc.h     | 13 +--------
 arch/sh/include/asm/pgalloc.h        |  3 ++
 arch/um/include/asm/pgalloc.h        |  8 +-----
 arch/um/include/asm/pgtable-3level.h |  3 --
 arch/um/kernel/mem.c                 | 12 --------
 arch/x86/include/asm/pgalloc.h       | 26 +----------------
 include/asm-generic/pgalloc.h        | 43 ++++++++++++++++++++++++++++
 13 files changed, 55 insertions(+), 135 deletions(-)
diff --git a/arch/alpha/include/asm/pgalloc.h b/arch/alpha/include/asm/pgalloc.h
index a1a29f60934c..4834cd52e9d0 100644
--- a/arch/alpha/include/asm/pgalloc.h
+++ b/arch/alpha/include/asm/pgalloc.h
@@ -5,7 +5,7 @@
 #include <linux/mm.h>
 #include <linux/mmzone.h>
 
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#include <asm-generic/pgalloc.h>
 
 /*      
  * Allocate and free page tables. The xxx_kernel() versions are
@@ -40,17 +40,4 @@ pgd_free(struct mm_struct *mm, pgd_t *pgd)
 	free_page((unsigned long)pgd);
 }
 
-static inline pmd_t *
-pmd_alloc_one(struct mm_struct *mm, unsigned long address)
-{
-	pmd_t *ret = (pmd_t *)__get_free_page(GFP_PGTABLE_USER);
-	return ret;
-}
-
-static inline void
-pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	free_page((unsigned long)pmd);
-}
-
 #endif /* _ALPHA_PGALLOC_H */
diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h
index 069da393110c..c5bdfd404ea5 100644
--- a/arch/arm/include/asm/pgalloc.h
+++ b/arch/arm/include/asm/pgalloc.h
@@ -22,17 +22,6 @@
 
 #ifdef CONFIG_ARM_LPAE
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	return (pmd_t *)get_zeroed_page(GFP_KERNEL);
-}
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
-	free_page((unsigned long)pmd);
-}
-
 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 {
 	set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 58e93583ddb6..7246d0a662e1 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -13,37 +13,12 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#include <asm-generic/pgalloc.h>
 
 #define PGD_SIZE	(PTRS_PER_PGD * sizeof(pgd_t))
 
 #if CONFIG_PGTABLE_LEVELS > 2
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	gfp_t gfp = GFP_PGTABLE_USER;
-	struct page *page;
-
-	if (mm == &init_mm)
-		gfp = GFP_PGTABLE_KERNEL;
-
-	page = alloc_page(gfp);
-	if (!page)
-		return NULL;
-	if (!pgtable_pmd_page_ctor(page)) {
-		__free_page(page);
-		return NULL;
-	}
-	return page_address(page);
-}
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
-{
-	BUG_ON((unsigned long)pmdp & (PAGE_SIZE-1));
-	pgtable_pmd_page_dtor(virt_to_page(pmdp));
-	free_page((unsigned long)pmdp);
-}
-
 static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
 {
 	set_pud(pudp, __pud(__phys_to_pud_val(pmdp) | prot));
diff --git a/arch/ia64/include/asm/pgalloc.h b/arch/ia64/include/asm/pgalloc.h
index 2a3050345099..5da1fc76477b 100644
--- a/arch/ia64/include/asm/pgalloc.h
+++ b/arch/ia64/include/asm/pgalloc.h
@@ -59,16 +59,6 @@ pud_populate(struct mm_struct *mm, pud_t * pud_entry, pmd_t * pmd)
 	pud_val(*pud_entry) = __pa(pmd);
 }
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	return (pmd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-}
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	free_page((unsigned long)pmd);
-}
-
 #define __pmd_free_tlb(tlb, pmd, address)	pmd_free((tlb)->mm, pmd)
 
 static inline void
diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h
index fa77cb71f303..eed1b3e8c642 100644
--- a/arch/mips/include/asm/pgalloc.h
+++ b/arch/mips/include/asm/pgalloc.h
@@ -13,7 +13,8 @@
 #include <linux/mm.h>
 #include <linux/sched.h>
 
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#define __HAVE_ARCH_PMD_ALLOC_ONE
+#include <asm-generic/pgalloc.h>
 
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
 	pte_t *pte)
@@ -70,11 +71,6 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 	return pmd;
 }
 
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	free_pages((unsigned long)pmd, PMD_ORDER);
-}
-
 #define __pmd_free_tlb(tlb, x, addr)	pmd_free((tlb)->mm, x)
 
 #endif
diff --git a/arch/parisc/include/asm/pgalloc.h b/arch/parisc/include/asm/pgalloc.h
index 9ac74da256b8..689766b914ed 100644
--- a/arch/parisc/include/asm/pgalloc.h
+++ b/arch/parisc/include/asm/pgalloc.h
@@ -10,7 +10,8 @@
 
 #include <asm/cache.h>
 
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#define __HAVE_ARCH_PMD_FREE
+#include <asm-generic/pgalloc.h>
 
 /* Allocate the top level pgd (page directory)
  *
@@ -65,14 +66,6 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 			(__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT)));
 }
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
-{
-	pmd_t *pmd = (pmd_t *)__get_free_pages(GFP_KERNEL, PMD_ORDER);
-	if (pmd)
-		memset(pmd, 0, PAGE_SIZE<<PMD_ORDER);
-	return pmd;
-}
-
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
 	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 3f601ee8233f..8d3135f05b8e 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -11,7 +11,7 @@
 #include <asm/tlb.h>
 
 #ifdef CONFIG_MMU
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#include <asm-generic/pgalloc.h>
 
 static inline void pmd_populate_kernel(struct mm_struct *mm,
 	pmd_t *pmd, pte_t *pte)
@@ -62,17 +62,6 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 
 #ifndef __PAGETABLE_PMD_FOLDED
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	return (pmd_t *)__get_free_page(
-		GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
-}
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	free_page((unsigned long)pmd);
-}
-
 #define __pmd_free_tlb(tlb, pmd, addr)  pmd_free((tlb)->mm, pmd)
 
 #endif /* __PAGETABLE_PMD_FOLDED */
diff --git a/arch/sh/include/asm/pgalloc.h b/arch/sh/include/asm/pgalloc.h
index 22d968bfe9bb..59263df76f51 100644
--- a/arch/sh/include/asm/pgalloc.h
+++ b/arch/sh/include/asm/pgalloc.h
@@ -3,6 +3,9 @@
 #define __ASM_SH_PGALLOC_H
 
 #include <asm/page.h>
+
+#define __HAVE_ARCH_PMD_ALLOC_ONE
+#define __HAVE_ARCH_PMD_FREE
 #include <asm-generic/pgalloc.h>
 
 extern pgd_t *pgd_alloc(struct mm_struct *);
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index 881e76da1938..bdde433dbdec 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -10,7 +10,7 @@
 
 #include <linux/mm.h>
 
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#include <asm-generic/pgalloc.h>
 
 #define pmd_populate_kernel(mm, pmd, pte) \
 	set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
@@ -34,12 +34,6 @@ do {							\
 } while (0)
 
 #ifdef CONFIG_3_LEVEL_PGTABLES
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	free_page((unsigned long)pmd);
-}
-
 #define __pmd_free_tlb(tlb,x, address)   tlb_remove_page((tlb),virt_to_page(x))
 #endif
 
diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h
index 36f452957cef..7e6a4180db9d 100644
--- a/arch/um/include/asm/pgtable-3level.h
+++ b/arch/um/include/asm/pgtable-3level.h
@@ -78,9 +78,6 @@ static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEWPAGE; }
 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
 #endif
 
-struct mm_struct;
-extern pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address);
-
 static inline void pud_clear (pud_t *pud)
 {
 	set_pud(pud, __pud(_PAGE_NEWPAGE));
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index c2ff76c8981e..a4accb14cbd5 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -201,18 +201,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 	free_page((unsigned long) pgd);
 }
 
-#ifdef CONFIG_3_LEVEL_PGTABLES
-pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
-{
-	pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
-
-	if (pmd)
-		memset(pmd, 0, PAGE_SIZE);
-
-	return pmd;
-}
-#endif
-
 void *uml_kmalloc(int size, int flags)
 {
 	return kmalloc(size, flags);
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index 29aa7859bdee..25feaa117c40 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -7,7 +7,7 @@
 #include <linux/pagemap.h>
 
 #define __HAVE_ARCH_PTE_ALLOC_ONE
-#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+#include <asm-generic/pgalloc.h>
 
 static inline int  __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
 
@@ -86,30 +86,6 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
 #if CONFIG_PGTABLE_LEVELS > 2
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	struct page *page;
-	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
-
-	if (mm == &init_mm)
-		gfp &= ~__GFP_ACCOUNT;
-	page = alloc_pages(gfp, 0);
-	if (!page)
-		return NULL;
-	if (!pgtable_pmd_page_ctor(page)) {
-		__free_pages(page, 0);
-		return NULL;
-	}
-	return (pmd_t *)page_address(page);
-}
-
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
-{
-	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
-	free_page((unsigned long)pmd);
-}
-
 extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
 
 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 73f7421413cb..1bc027891a00 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -102,6 +102,49 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
 	__free_page(pte_page);
 }
 
+
+#if CONFIG_PGTABLE_LEVELS > 2
+
+#ifndef __HAVE_ARCH_PMD_ALLOC_ONE
+/**
+ * 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().
+ * Allocations use %GFP_PGTABLE_USER in user context and
+ * %GFP_PGTABLE_KERNEL in kernel context.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+	struct page *page;
+	gfp_t gfp = GFP_PGTABLE_USER;
+
+	if (mm == &init_mm)
+		gfp = GFP_PGTABLE_KERNEL;
+	page = alloc_pages(gfp, 0);
+	if (!page)
+		return NULL;
+	if (!pgtable_pmd_page_ctor(page)) {
+		__free_pages(page, 0);
+		return NULL;
+	}
+	return (pmd_t *)page_address(page);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMD_FREE
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+	BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	free_page((unsigned long)pmd);
+}
+#endif
+
+#endif /* CONFIG_PGTABLE_LEVELS > 2 */
+
 #endif /* CONFIG_MMU */
 
 #endif /* __ASM_GENERIC_PGALLOC_H */
-- 
2.26.2


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