From: Jeremy Fitzhardinge Date: Mon, 17 Mar 2008 23:37:14 +0000 (-0700) Subject: x86: unify pgd ctor/dtor X-Git-Tag: tegra-9.12.3~6738^2~30 X-Git-Url: https://nv-tegra.nvidia.com/r/gitweb?p=linux-2.6.git;a=commitdiff_plain;h=85958b465c2e0de315575b1d3d7e7c2ce7126880 x86: unify pgd ctor/dtor All pagetables need fundamentally the same setup and destruction, so just use the same code for everything. Signed-off-by: Jeremy Fitzhardinge Cc: Andi Kleen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index e2ac320e615..50159764f69 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -59,50 +59,6 @@ static inline void pgd_list_del(pgd_t *pgd) list_del(&page->lru); } -#ifdef CONFIG_X86_64 -pgd_t *pgd_alloc(struct mm_struct *mm) -{ - unsigned boundary; - pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); - unsigned long flags; - if (!pgd) - return NULL; - spin_lock_irqsave(&pgd_lock, flags); - pgd_list_add(pgd); - spin_unlock_irqrestore(&pgd_lock, flags); - /* - * Copy kernel pointers in from init. - * Could keep a freelist or slab cache of those because the kernel - * part never changes. - */ - boundary = pgd_index(__PAGE_OFFSET); - memset(pgd, 0, boundary * sizeof(pgd_t)); - memcpy(pgd + boundary, - init_level4_pgt + boundary, - (PTRS_PER_PGD - boundary) * sizeof(pgd_t)); - return pgd; -} - -void pgd_free(struct mm_struct *mm, pgd_t *pgd) -{ - unsigned long flags; - BUG_ON((unsigned long)pgd & (PAGE_SIZE-1)); - spin_lock_irqsave(&pgd_lock, flags); - pgd_list_del(pgd); - spin_unlock_irqrestore(&pgd_lock, flags); - free_page((unsigned long)pgd); -} -#else -/* - * List of all pgd's needed for non-PAE so it can invalidate entries - * in both cached and uncached pgd's; not needed for PAE since the - * kernel pmd is shared. If PAE were not to share the pmd a similar - * tactic would be needed. This is essentially codepath-based locking - * against pageattr.c; it is the unique case in which a valid change - * of kernel pagetables can't be lazily synchronized by vmalloc faults. - * vmalloc faults work because attached pagetables are never freed. - * -- wli - */ #define UNSHARED_PTRS_PER_PGD \ (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD) @@ -120,7 +76,8 @@ static void pgd_ctor(void *p) ptes in non-PAE, or shared PMD in PAE), then just copy the references from swapper_pg_dir. */ if (PAGETABLE_LEVELS == 2 || - (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) { + (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || + PAGETABLE_LEVELS == 4) { clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, swapper_pg_dir + KERNEL_PGD_BOUNDARY, KERNEL_PGD_PTRS); @@ -149,6 +106,17 @@ static void pgd_dtor(void *pgd) spin_unlock_irqrestore(&pgd_lock, flags); } +/* + * List of all pgd's needed for non-PAE so it can invalidate entries + * in both cached and uncached pgd's; not needed for PAE since the + * kernel pmd is shared. If PAE were not to share the pmd a similar + * tactic would be needed. This is essentially codepath-based locking + * against pageattr.c; it is the unique case in which a valid change + * of kernel pagetables can't be lazily synchronized by vmalloc faults. + * vmalloc faults work because attached pagetables are never freed. + * -- wli + */ + #ifdef CONFIG_X86_PAE /* * Mop up any pmd pages which may still be attached to the pgd. @@ -264,7 +232,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd) pgd_dtor(pgd); free_page((unsigned long)pgd); } -#endif int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index e61075e70a5..b8a08bd7bd4 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -438,6 +438,22 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, pte_update(mm, addr, ptep); } +/* + * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); + * + * dst - pointer to pgd range anwhere on a pgd page + * src - "" + * count - the number of pgds to copy. + * + * dst and src can be on the same page, but the range must not overlap, + * and must not cross a page boundary. + */ +static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) +{ + memcpy(dst, src, count * sizeof(pgd_t)); +} + + #include #endif /* __ASSEMBLY__ */ diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h index cc52da32fbe..168b6447cf1 100644 --- a/include/asm-x86/pgtable_32.h +++ b/include/asm-x86/pgtable_32.h @@ -105,21 +105,6 @@ extern int pmd_bad(pmd_t pmd); # include #endif -/* - * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); - * - * dst - pointer to pgd range anwhere on a pgd page - * src - "" - * count - the number of pgds to copy. - * - * dst and src can be on the same page, but the range must not overlap, - * and must not cross a page boundary. - */ -static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) -{ - memcpy(dst, src, count * sizeof(pgd_t)); -} - /* * Macro to mark a page protection value as "uncacheable". * On processors which do not support it, this is a no-op. diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h index 9fd87d0b647..a3bbf8766c1 100644 --- a/include/asm-x86/pgtable_64.h +++ b/include/asm-x86/pgtable_64.h @@ -24,7 +24,7 @@ extern void paging_init(void); #endif /* !__ASSEMBLY__ */ -#define SHARED_KERNEL_PMD 1 +#define SHARED_KERNEL_PMD 0 /* * PGDIR_SHIFT determines what a top-level page table entry can map