diff options
Diffstat (limited to 'arch/x86/mm/pgtable.c')
| -rw-r--r-- | arch/x86/mm/pgtable.c | 156 |
1 files changed, 49 insertions, 107 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index f7ae44d3dd9e..62777ba4de1a 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -10,6 +10,7 @@ #ifdef CONFIG_DYNAMIC_PHYSICAL_MASK phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1; EXPORT_SYMBOL(physical_mask); +SYM_PIC_ALIAS(physical_mask); #endif pgtable_t pte_alloc_one(struct mm_struct *mm) @@ -68,12 +69,6 @@ static inline void pgd_list_del(pgd_t *pgd) list_del(&ptdesc->pt_list); } -#define UNSHARED_PTRS_PER_PGD \ - (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD) -#define MAX_UNSHARED_PTRS_PER_PGD \ - MAX_T(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD) - - static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm) { virt_to_ptdesc(pgd)->pt_mm = mm; @@ -86,29 +81,19 @@ struct mm_struct *pgd_page_get_mm(struct page *page) static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd) { - /* If the pgd points to a shared pagetable level (either the - ptes in non-PAE, or shared PMD in PAE), then just copy the - references from swapper_pg_dir. */ - if (CONFIG_PGTABLE_LEVELS == 2 || - (CONFIG_PGTABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || - CONFIG_PGTABLE_LEVELS >= 4) { + /* PAE preallocates all its PMDs. No cloning needed. */ + if (!IS_ENABLED(CONFIG_X86_PAE)) clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, swapper_pg_dir + KERNEL_PGD_BOUNDARY, KERNEL_PGD_PTRS); - } - /* list required to sync kernel mapping updates */ - if (!SHARED_KERNEL_PMD) { - pgd_set_mm(pgd, mm); - pgd_list_add(pgd); - } + /* List used to sync kernel mapping updates */ + pgd_set_mm(pgd, mm); + pgd_list_add(pgd); } static void pgd_dtor(pgd_t *pgd) { - if (SHARED_KERNEL_PMD) - return; - spin_lock(&pgd_lock); pgd_list_del(pgd); spin_unlock(&pgd_lock); @@ -132,15 +117,15 @@ static void pgd_dtor(pgd_t *pgd) * processor notices the update. Since this is expensive, and * all 4 top-level entries are used almost immediately in a * new process's life, we just pre-populate them here. - * - * Also, if we're in a paravirt environment where the kernel pmd is - * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate - * and initialize the kernel pmds here. */ -#define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD -#define MAX_PREALLOCATED_PMDS MAX_UNSHARED_PTRS_PER_PGD +#define PREALLOCATED_PMDS PTRS_PER_PGD /* + * "USER_PMDS" are the PMDs for the user copy of the page tables when + * PTI is enabled. They do not exist when PTI is disabled. Note that + * this is distinct from the user _portion_ of the kernel page tables + * which always exists. + * * We allocate separate PMDs for the kernel part of the user page-table * when PTI is enabled. We need them to map the per-process LDT into the * user-space page-table. @@ -169,7 +154,6 @@ void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) /* No need to prepopulate any pagetable entries in non-PAE modes. */ #define PREALLOCATED_PMDS 0 -#define MAX_PREALLOCATED_PMDS 0 #define PREALLOCATED_USER_PMDS 0 #define MAX_PREALLOCATED_USER_PMDS 0 #endif /* CONFIG_X86_PAE */ @@ -318,68 +302,15 @@ static void pgd_prepopulate_user_pmd(struct mm_struct *mm, { } #endif -/* - * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also - * assumes that pgd should be in one page. - * - * But kernel with PAE paging that is not running as a Xen domain - * only needs to allocate 32 bytes for pgd instead of one page. - */ -#ifdef CONFIG_X86_PAE - -#include <linux/slab.h> - -#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t)) -#define PGD_ALIGN 32 - -static struct kmem_cache *pgd_cache; - -void __init pgtable_cache_init(void) -{ - /* - * When PAE kernel is running as a Xen domain, it does not use - * shared kernel pmd. And this requires a whole page for pgd. - */ - if (!SHARED_KERNEL_PMD) - return; - - /* - * when PAE kernel is not running as a Xen domain, it uses - * shared kernel pmd. Shared kernel pmd does not require a whole - * page for pgd. We are able to just allocate a 32-byte for pgd. - * During boot time, we create a 32-byte slab for pgd table allocation. - */ - pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN, - SLAB_PANIC, NULL); -} static inline pgd_t *_pgd_alloc(struct mm_struct *mm) { /* - * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain. - * We allocate one page for pgd. - */ - if (!SHARED_KERNEL_PMD) - return __pgd_alloc(mm, 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. + * PTI and Xen need a whole page for the PAE PGD + * even though the hardware only needs 32 bytes. + * + * For simplicity, allocate a page for all users. */ - return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER); -} - -static inline void _pgd_free(struct mm_struct *mm, pgd_t *pgd) -{ - if (!SHARED_KERNEL_PMD) - __pgd_free(mm, pgd); - else - kmem_cache_free(pgd_cache, pgd); -} -#else - -static inline pgd_t *_pgd_alloc(struct mm_struct *mm) -{ return __pgd_alloc(mm, pgd_allocation_order()); } @@ -387,13 +318,12 @@ static inline void _pgd_free(struct mm_struct *mm, pgd_t *pgd) { __pgd_free(mm, pgd); } -#endif /* CONFIG_X86_PAE */ pgd_t *pgd_alloc(struct mm_struct *mm) { pgd_t *pgd; pmd_t *u_pmds[MAX_PREALLOCATED_USER_PMDS]; - pmd_t *pmds[MAX_PREALLOCATED_PMDS]; + pmd_t *pmds[PREALLOCATED_PMDS]; pgd = _pgd_alloc(mm); @@ -613,11 +543,11 @@ pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address, #endif /** - * reserve_top_address - reserves a hole in the top of kernel address space - * @reserve - size of hole to reserve + * reserve_top_address - Reserve a hole in the top of the kernel address space + * @reserve: Size of hole to reserve * * Can be used to relocate the fixmap area and poke a hole in the top - * of kernel address space to make room for a hypervisor. + * of the kernel address space to make room for a hypervisor. */ void __init reserve_top_address(unsigned long reserve) { @@ -662,9 +592,12 @@ void native_set_fixmap(unsigned /* enum fixed_addresses */ idx, } #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP -#ifdef CONFIG_X86_5LEVEL +#if CONFIG_PGTABLE_LEVELS > 4 /** - * p4d_set_huge - setup kernel P4D mapping + * p4d_set_huge - Set up kernel P4D mapping + * @p4d: Pointer to the P4D entry + * @addr: Virtual address associated with the P4D entry + * @prot: Protection bits to use * * No 512GB pages yet -- always return 0 */ @@ -674,9 +607,10 @@ int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot) } /** - * p4d_clear_huge - clear kernel P4D mapping when it is set + * p4d_clear_huge - Clear kernel P4D mapping when it is set + * @p4d: Pointer to the P4D entry to clear * - * No 512GB pages yet -- always return 0 + * No 512GB pages yet -- do nothing */ void p4d_clear_huge(p4d_t *p4d) { @@ -684,7 +618,10 @@ void p4d_clear_huge(p4d_t *p4d) #endif /** - * pud_set_huge - setup kernel PUD mapping + * pud_set_huge - Set up kernel PUD mapping + * @pud: Pointer to the PUD entry + * @addr: Virtual address associated with the PUD entry + * @prot: Protection bits to use * * MTRRs can override PAT memory types with 4KiB granularity. Therefore, this * function sets up a huge page only if the complete range has the same MTRR @@ -715,7 +652,10 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) } /** - * pmd_set_huge - setup kernel PMD mapping + * pmd_set_huge - Set up kernel PMD mapping + * @pmd: Pointer to the PMD entry + * @addr: Virtual address associated with the PMD entry + * @prot: Protection bits to use * * See text over pud_set_huge() above. * @@ -744,7 +684,8 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) } /** - * pud_clear_huge - clear kernel PUD mapping when it is set + * pud_clear_huge - Clear kernel PUD mapping when it is set + * @pud: Pointer to the PUD entry to clear. * * Returns 1 on success and 0 on failure (no PUD map is found). */ @@ -759,7 +700,8 @@ int pud_clear_huge(pud_t *pud) } /** - * pmd_clear_huge - clear kernel PMD mapping when it is set + * pmd_clear_huge - Clear kernel PMD mapping when it is set + * @pmd: Pointer to the PMD entry to clear. * * Returns 1 on success and 0 on failure (no PMD map is found). */ @@ -775,11 +717,11 @@ int pmd_clear_huge(pmd_t *pmd) #ifdef CONFIG_X86_64 /** - * pud_free_pmd_page - Clear pud entry and free pmd page. - * @pud: Pointer to a PUD. - * @addr: Virtual address associated with pud. + * pud_free_pmd_page - Clear PUD entry and free PMD page + * @pud: Pointer to a PUD + * @addr: Virtual address associated with PUD * - * Context: The pud range has been unmapped and TLB purged. + * Context: The PUD range has been unmapped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. * * NOTE: Callers must allow a single page allocation. @@ -822,11 +764,11 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr) } /** - * pmd_free_pte_page - Clear pmd entry and free pte page. - * @pmd: Pointer to a PMD. - * @addr: Virtual address associated with pmd. + * pmd_free_pte_page - Clear PMD entry and free PTE page. + * @pmd: Pointer to the PMD + * @addr: Virtual address associated with PMD * - * Context: The pmd range has been unmapped and TLB purged. + * Context: The PMD range has been unmapped and TLB purged. * Return: 1 if clearing the entry succeeded. 0 otherwise. */ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) @@ -848,7 +790,7 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) /* * Disable free page handling on x86-PAE. This assures that ioremap() - * does not update sync'd pmd entries. See vmalloc_sync_one(). + * does not update sync'd PMD entries. See vmalloc_sync_one(). */ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { |