[PATCH 04/15] arm64: switch to generic version of pte allocation

Mike Rapoport
2019-05-02T15:28:31Z

The PTE allocations in arm64 are identical to the generic ones modulo the
GFP flags.

Using the generic pte_alloc_one() functions ensures that the user page
tables are allocated with __GFP_ACCOUNT set.

The arm64 definition of PGALLOC_GFP is removed and replaced with
GFP_PGTABLE_USER for p[gum]d_alloc_one() and for KVM memory cache.

The mappings created with create_pgd_mapping() are now using
GFP_PGTABLE_KERNEL.

The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.

The pte_free() version on arm64 is identical to the generic one and
can be simply dropped.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/arm64/include/asm/pgalloc.h | 43 ++++------------------------------------
arch/arm64/mm/mmu.c | 2 +-
arch/arm64/mm/pgd.c | 4 ++--
virt/kvm/arm/mmu.c | 2 +-
4 files changed, 8 insertions(+), 43 deletions(-)

diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 52fa47c..3293b8b 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -24,16 +24,17 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
#define check_pgt_cache() do { } while (0)

-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
#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)
{
- return (pmd_t *)__get_free_page(PGALLOC_GFP);
+ return (pmd_t *)__get_free_page(GFP_PGTABLE_USER);
}

static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
@@ -62,7 +63,7 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)

static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- return (pud_t *)__get_free_page(PGALLOC_GFP);
+ return (pud_t *)__get_free_page(GFP_PGTABLE_USER);
}

static inline void pud_free(struct mm_struct *mm, pud_t *pudp)
@@ -90,42 +91,6 @@ static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t pudp, pgdval_t prot)
extern pgd_t *pgd_alloc(struct mm_struct *mm);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgdp);

-static inline pte_t *
-pte_alloc_one_kernel(struct mm_struct *mm)
-{
- return (pte_t *)__get_free_page(PGALLOC_GFP);
-}
-
-static inline pgtable_t
-pte_alloc_one(struct mm_struct *mm)
-{
- struct page *pte;
-
- pte = alloc_pages(PGALLOC_GFP, 0);
- if (!pte)
- return NULL;
- if (!pgtable_page_ctor(pte)) {
- __free_page(pte);
- return NULL;
- }
- return pte;
-}
-
-/*
- * Free a PTE table.
- */
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *ptep)
-{
- if (ptep)
- free_page((unsigned long)ptep);
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
- pgtable_page_dtor(pte);
- __free_page(pte);
-}
-
static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t ptep,
pmdval_t prot)
{
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index e97f018..d5178c5 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -373,7 +373,7 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,

static phys_addr_t pgd_pgtable_alloc(void)
{
- void *ptr = (void *)__get_free_page(PGALLOC_GFP);
+ void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL);
if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
BUG();

diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c
index 289f911..2ef1a53 100644
--- a/arch/arm64/mm/pgd.c
+++ b/arch/arm64/mm/pgd.c
@@ -31,9 +31,9 @@ static struct kmem_cache *pgd_cache __ro_after_init;
pgd_t *pgd_alloc(struct mm_struct *mm)
{
if (PGD_SIZE == PAGE_SIZE)
- return (pgd_t *)__get_free_page(PGALLOC_GFP);
+ return (pgd_t *)__get_free_page(GFP_PGTABLE_USER);
else
- return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+ return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER);
}

void pgd_free(struct mm_struct *mm, pgd_t *pgd)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 27c9583..9f6f638 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -141,7 +141,7 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
if (cache->nobjs >= min)
return 0;
while (cache->nobjs < max) {
- page = (void *)__get_free_page(PGALLOC_GFP);
+ page = (void *)__get_free_page(GFP_PGTABLE_USER);
if (!page)
return -ENOMEM;
cache->objects[cache->nobjs++] = page;
--
2.7.4