| Message ID | 1556810922-20248-5-git-send-email-rppt@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | introduce generic pte_{alloc,free}_one[_kernel] | expand |
Hi, On Thu, May 02, 2019 at 06:28:31PM +0300, Mike Rapoport wrote: > 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/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); > } In efi_virtmap_init() we use pgd_alloc() to allocate a pgd for EFI runtime services, which we map with a special kernel page table. I'm not sure if accounting that is problematic, as it's allocated in a kernel thread off the back of an early_initcall. Just to check, Is that sound, or do we need a pgd_alloc_kernel()? Thanks, Mark.
On Fri, May 03, 2019 at 11:05:09AM +0100, Mark Rutland wrote: > Hi, > > On Thu, May 02, 2019 at 06:28:31PM +0300, Mike Rapoport wrote: > > 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/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); > > } > > In efi_virtmap_init() we use pgd_alloc() to allocate a pgd for EFI > runtime services, which we map with a special kernel page table. > > I'm not sure if accounting that is problematic, as it's allocated in a > kernel thread off the back of an early_initcall. The accounting bypasses kernel threads so there should be no problem. > Just to check, Is that sound, or do we need a pgd_alloc_kernel()? > > Thanks, > Mark. >
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;
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(-)