[PATCH] mm: Introduce GFP_PGTABLE

From: Anshuman Khandual
Date: Sat Jan 12 2019 - 05:27:54 EST

All architectures have been defining their own PGALLOC_GFP as (GFP_KERNEL |
__GFP_ZERO) and using it for allocating page table pages. This causes some
code duplication which can be easily avoided. GFP_KERNEL allocated and
cleared out pages (__GFP_ZERO) are required for page tables on any given
architecture. This creates a new generic GFP flag flag which can be used
for any page table page allocation. Does not cause any functional change.

Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/arm/include/asm/pgalloc.h | 8 +++-----
arch/arm/mm/mmu.c | 2 +-
arch/arm64/include/asm/pgalloc.h | 9 ++++-----
arch/arm64/mm/mmu.c | 2 +-
arch/arm64/mm/pgd.c | 4 ++--
arch/powerpc/include/asm/book3s/64/pgalloc.h | 4 ++--
arch/powerpc/include/asm/pgalloc.h | 2 --
arch/powerpc/mm/pgtable-frag.c | 4 ++--
arch/sh/mm/pgtable.c | 6 ++----
arch/unicore32/include/asm/pgalloc.h | 6 ++----
arch/x86/kernel/espfix_64.c | 6 ++----
arch/x86/mm/pgtable.c | 14 ++++++--------
include/linux/gfp.h | 1 +
virt/kvm/arm/mmu.c | 2 +-
14 files changed, 29 insertions(+), 41 deletions(-)

diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h
index 17ab72f..72be6f5 100644
--- a/arch/arm/include/asm/pgalloc.h
+++ b/arch/arm/include/asm/pgalloc.h
@@ -57,8 +57,6 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
extern pgd_t *pgd_alloc(struct mm_struct *mm);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);

-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
-
static inline void clean_pte_table(pte_t *pte)
{
clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
@@ -85,7 +83,7 @@ pte_alloc_one_kernel(struct mm_struct *mm)
{
pte_t *pte;

- pte = (pte_t *)__get_free_page(PGALLOC_GFP);
+ pte = (pte_t *)__get_free_page(GFP_PGTABLE);
if (pte)
clean_pte_table(pte);

@@ -98,9 +96,9 @@ pte_alloc_one(struct mm_struct *mm)
struct page *pte;

#ifdef CONFIG_HIGHPTE
- pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
+ pte = alloc_pages(GFP_PGTABLE | __GFP_HIGHMEM, 0);
#else
- pte = alloc_pages(PGALLOC_GFP, 0);
+ pte = alloc_pages(GFP_PGTABLE, 0);
#endif
if (!pte)
return NULL;
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index f5cc1cc..6d47784 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -733,7 +733,7 @@ static void __init *early_alloc(unsigned long sz)

static void *__init late_alloc(unsigned long sz)
{
- void *ptr = (void *)__get_free_pages(PGALLOC_GFP, get_order(sz));
+ void *ptr = (void *)__get_free_pages(GFP_PGTABLE, get_order(sz));

if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
BUG();
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 52fa47c..d5c75bf 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -26,14 +26,13 @@

#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);
}

static inline void pmd_free(struct mm_struct *mm, pmd_t *pmdp)
@@ -62,7 +61,7 @@ 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);
}

static inline void pud_free(struct mm_struct *mm, pud_t *pudp)
@@ -93,7 +92,7 @@ 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);
+ return (pte_t *)__get_free_page(GFP_PGTABLE);
}

static inline pgtable_t
@@ -101,7 +100,7 @@ pte_alloc_one(struct mm_struct *mm)
{
struct page *pte;

- pte = alloc_pages(PGALLOC_GFP, 0);
+ pte = alloc_pages(GFP_PGTABLE, 0);
if (!pte)
return NULL;
if (!pgtable_page_ctor(pte)) {
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index b6f5aa5..07b1c0f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -372,7 +372,7 @@ 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);
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..5b28e2b 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);
else
- return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+ return kmem_cache_alloc(pgd_cache, GFP_PGTABLE);
}

void pgd_free(struct mm_struct *mm, pgd_t *pgd)
diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h
index 9c11732..8a7235e 100644
--- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
@@ -52,10 +52,10 @@ void pte_frag_destroy(void *pte_frag);
static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm)
{
#ifdef CONFIG_PPC_64K_PAGES
- return (pgd_t *)__get_free_page(pgtable_gfp_flags(mm, PGALLOC_GFP));
+ return (pgd_t *)__get_free_page(pgtable_gfp_flags(mm, GFP_PGTABLE));
#else
struct page *page;
- page = alloc_pages(pgtable_gfp_flags(mm, PGALLOC_GFP | __GFP_RETRY_MAYFAIL),
+ page = alloc_pages(pgtable_gfp_flags(mm, GFP_PGTABLE | __GFP_RETRY_MAYFAIL),
4);
if (!page)
return NULL;
diff --git a/arch/powerpc/include/asm/pgalloc.h b/arch/powerpc/include/asm/pgalloc.h
index e11f030..3b11e8b 100644
--- a/arch/powerpc/include/asm/pgalloc.h
+++ b/arch/powerpc/include/asm/pgalloc.h
@@ -18,8 +18,6 @@ static inline gfp_t pgtable_gfp_flags(struct mm_struct *mm, gfp_t gfp)
}
#endif /* MODULE */

-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
-
#ifdef CONFIG_PPC_BOOK3S
#include <asm/book3s/pgalloc.h>
#else
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index a7b0521..211aaa7 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c
@@ -58,7 +58,7 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
struct page *page;

if (!kernel) {
- page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
+ page = alloc_page(GFP_PGTABLE | __GFP_ACCOUNT);
if (!page)
return NULL;
if (!pgtable_page_ctor(page)) {
@@ -66,7 +66,7 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm, int kernel)
return NULL;
}
} else {
- page = alloc_page(PGALLOC_GFP);
+ page = alloc_page(GFP_PGTABLE);
if (!page)
return NULL;
}
diff --git a/arch/sh/mm/pgtable.c b/arch/sh/mm/pgtable.c
index 5c8f924..324732dc5 100644
--- a/arch/sh/mm/pgtable.c
+++ b/arch/sh/mm/pgtable.c
@@ -2,8 +2,6 @@
#include <linux/mm.h>
#include <linux/slab.h>

-#define PGALLOC_GFP GFP_KERNEL | __GFP_ZERO
-
static struct kmem_cache *pgd_cachep;
#if PAGETABLE_LEVELS > 2
static struct kmem_cache *pmd_cachep;
@@ -32,7 +30,7 @@ void pgtable_cache_init(void)

pgd_t *pgd_alloc(struct mm_struct *mm)
{
- return kmem_cache_alloc(pgd_cachep, PGALLOC_GFP);
+ return kmem_cache_alloc(pgd_cachep, GFP_PGTABLE);
}

void pgd_free(struct mm_struct *mm, pgd_t *pgd)
@@ -48,7 +46,7 @@ void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)

pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
{
- return kmem_cache_alloc(pmd_cachep, PGALLOC_GFP);
+ return kmem_cache_alloc(pmd_cachep, GFP_PGTABLE);
}

void pmd_free(struct mm_struct *mm, pmd_t *pmd)
diff --git a/arch/unicore32/include/asm/pgalloc.h b/arch/unicore32/include/asm/pgalloc.h
index 7cceabe..a3506e5 100644
--- a/arch/unicore32/include/asm/pgalloc.h
+++ b/arch/unicore32/include/asm/pgalloc.h
@@ -28,8 +28,6 @@ extern void free_pgd_slow(struct mm_struct *mm, pgd_t *pgd);
#define pgd_alloc(mm) get_pgd_slow(mm)
#define pgd_free(mm, pgd) free_pgd_slow(mm, pgd)

-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
-
/*
* Allocate one PTE table.
*/
@@ -38,7 +36,7 @@ pte_alloc_one_kernel(struct mm_struct *mm)
{
pte_t *pte;

- pte = (pte_t *)__get_free_page(PGALLOC_GFP);
+ pte = (pte_t *)__get_free_page(GFP_PGTABLE);
if (pte)
clean_dcache_area(pte, PTRS_PER_PTE * sizeof(pte_t));

@@ -50,7 +48,7 @@ pte_alloc_one(struct mm_struct *mm)
{
struct page *pte;

- pte = alloc_pages(PGALLOC_GFP, 0);
+ pte = alloc_pages(GFP_PGTABLE, 0);
if (!pte)
return NULL;
if (!PageHighMem(pte)) {
diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c
index aebd0d5..dae28cc 100644
--- a/arch/x86/kernel/espfix_64.c
+++ b/arch/x86/kernel/espfix_64.c
@@ -57,8 +57,6 @@
# error "Need more virtual address space for the ESPFIX hack"
#endif

-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
-
/* This contains the *bottom* address of the espfix stack */
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, espfix_stack);
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, espfix_waddr);
@@ -172,7 +170,7 @@ void init_espfix_ap(int cpu)
pud_p = &espfix_pud_page[pud_index(addr)];
pud = *pud_p;
if (!pud_present(pud)) {
- struct page *page = alloc_pages_node(node, PGALLOC_GFP, 0);
+ struct page *page = alloc_pages_node(node, GFP_PGTABLE, 0);

pmd_p = (pmd_t *)page_address(page);
pud = __pud(__pa(pmd_p) | (PGTABLE_PROT & ptemask));
@@ -184,7 +182,7 @@ void init_espfix_ap(int cpu)
pmd_p = pmd_offset(&pud, addr);
pmd = *pmd_p;
if (!pmd_present(pmd)) {
- struct page *page = alloc_pages_node(node, PGALLOC_GFP, 0);
+ struct page *page = alloc_pages_node(node, GFP_PGTABLE, 0);

pte_p = (pte_t *)page_address(page);
pmd = __pmd(__pa(pte_p) | (PGTABLE_PROT & ptemask));
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7bd0170..d608b03 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -13,19 +13,17 @@ phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
EXPORT_SYMBOL(physical_mask);
#endif

-#define PGALLOC_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
-
#ifdef CONFIG_HIGHPTE
#define PGALLOC_USER_GFP __GFP_HIGHMEM
#else
#define PGALLOC_USER_GFP 0
#endif

-gfp_t __userpte_alloc_gfp = PGALLOC_GFP | PGALLOC_USER_GFP;
+gfp_t __userpte_alloc_gfp = GFP_PGTABLE | PGALLOC_USER_GFP;

pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
{
- return (pte_t *)__get_free_page(PGALLOC_GFP & ~__GFP_ACCOUNT);
+ return (pte_t *)__get_free_page(GFP_PGTABLE & ~__GFP_ACCOUNT);
}

pgtable_t pte_alloc_one(struct mm_struct *mm)
@@ -235,7 +233,7 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
{
int i;
bool failed = false;
- gfp_t gfp = PGALLOC_GFP;
+ gfp_t gfp = GFP_PGTABLE;

if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
@@ -401,14 +399,14 @@ static inline pgd_t *_pgd_alloc(void)
* We allocate one page for pgd.
*/
if (!SHARED_KERNEL_PMD)
- return (pgd_t *)__get_free_pages(PGALLOC_GFP,
+ return (pgd_t *)__get_free_pages(GFP_PGTABLE,
PGD_ALLOCATION_ORDER);

/*
* Now PAE kernel is not running as a Xen domain. We can allocate
* a 32-byte slab for pgd to save memory space.
*/
- return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+ return kmem_cache_alloc(pgd_cache, GFP_PGTABLE);
}

static inline void _pgd_free(pgd_t *pgd)
@@ -422,7 +420,7 @@ static inline void _pgd_free(pgd_t *pgd)

static inline pgd_t *_pgd_alloc(void)
{
- return (pgd_t *)__get_free_pages(PGALLOC_GFP, PGD_ALLOCATION_ORDER);
+ return (pgd_t *)__get_free_pages(GFP_PGTABLE, PGD_ALLOCATION_ORDER);
}

static inline void _pgd_free(pgd_t *pgd)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 5f5e25f..a8414be 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -300,6 +300,7 @@ struct vm_area_struct;
#define GFP_TRANSHUGE_LIGHT ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
__GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
#define GFP_TRANSHUGE (GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)
+#define GFP_PGTABLE (GFP_KERNEL | __GFP_ZERO)

/* Convert GFP flags to their corresponding migrate type */
#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index fbdf3ac..f60a5b8 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -143,7 +143,7 @@ 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);
if (!page)
return -ENOMEM;
cache->objects[cache->nobjs++] = page;
--
2.7.4