Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 1 | #include <linux/mm.h> |
| 2 | #include <asm/pgalloc.h> |
Jeremy Fitzhardinge | ee5aa8d | 2008-03-17 16:37:03 -0700 | [diff] [blame] | 3 | #include <asm/pgtable.h> |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 4 | #include <asm/tlb.h> |
| 5 | |
| 6 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) |
| 7 | { |
| 8 | return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); |
| 9 | } |
| 10 | |
| 11 | pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) |
| 12 | { |
| 13 | struct page *pte; |
| 14 | |
| 15 | #ifdef CONFIG_HIGHPTE |
| 16 | pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0); |
| 17 | #else |
| 18 | pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0); |
| 19 | #endif |
| 20 | if (pte) |
| 21 | pgtable_page_ctor(pte); |
| 22 | return pte; |
| 23 | } |
| 24 | |
Jeremy Fitzhardinge | 397f687 | 2008-03-17 16:36:57 -0700 | [diff] [blame] | 25 | void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte) |
| 26 | { |
| 27 | pgtable_page_dtor(pte); |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 28 | paravirt_release_pte(page_to_pfn(pte)); |
Jeremy Fitzhardinge | 397f687 | 2008-03-17 16:36:57 -0700 | [diff] [blame] | 29 | tlb_remove_page(tlb, pte); |
| 30 | } |
| 31 | |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 32 | #if PAGETABLE_LEVELS > 2 |
| 33 | void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) |
| 34 | { |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 35 | paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 36 | tlb_remove_page(tlb, virt_to_page(pmd)); |
| 37 | } |
Jeremy Fitzhardinge | 5a5f8f4 | 2008-03-17 16:36:59 -0700 | [diff] [blame] | 38 | |
| 39 | #if PAGETABLE_LEVELS > 3 |
| 40 | void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) |
| 41 | { |
Jeremy Fitzhardinge | 2761fa0 | 2008-03-17 16:37:02 -0700 | [diff] [blame] | 42 | paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 5a5f8f4 | 2008-03-17 16:36:59 -0700 | [diff] [blame] | 43 | tlb_remove_page(tlb, virt_to_page(pud)); |
| 44 | } |
| 45 | #endif /* PAGETABLE_LEVELS > 3 */ |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 46 | #endif /* PAGETABLE_LEVELS > 2 */ |
| 47 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 48 | static inline void pgd_list_add(pgd_t *pgd) |
| 49 | { |
| 50 | struct page *page = virt_to_page(pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 51 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 52 | list_add(&page->lru, &pgd_list); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 53 | } |
| 54 | |
| 55 | static inline void pgd_list_del(pgd_t *pgd) |
| 56 | { |
| 57 | struct page *page = virt_to_page(pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 58 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 59 | list_del(&page->lru); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 60 | } |
| 61 | |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 62 | #ifdef CONFIG_X86_64 |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 63 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 64 | { |
| 65 | unsigned boundary; |
| 66 | pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT); |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 67 | unsigned long flags; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 68 | if (!pgd) |
| 69 | return NULL; |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 70 | spin_lock_irqsave(&pgd_lock, flags); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 71 | pgd_list_add(pgd); |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 72 | spin_unlock_irqrestore(&pgd_lock, flags); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 73 | /* |
| 74 | * Copy kernel pointers in from init. |
| 75 | * Could keep a freelist or slab cache of those because the kernel |
| 76 | * part never changes. |
| 77 | */ |
| 78 | boundary = pgd_index(__PAGE_OFFSET); |
| 79 | memset(pgd, 0, boundary * sizeof(pgd_t)); |
| 80 | memcpy(pgd + boundary, |
| 81 | init_level4_pgt + boundary, |
| 82 | (PTRS_PER_PGD - boundary) * sizeof(pgd_t)); |
| 83 | return pgd; |
| 84 | } |
| 85 | |
| 86 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 87 | { |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 88 | unsigned long flags; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 89 | BUG_ON((unsigned long)pgd & (PAGE_SIZE-1)); |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 90 | spin_lock_irqsave(&pgd_lock, flags); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 91 | pgd_list_del(pgd); |
Jeremy Fitzhardinge | 3941585 | 2008-03-17 16:37:00 -0700 | [diff] [blame] | 92 | spin_unlock_irqrestore(&pgd_lock, flags); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 93 | free_page((unsigned long)pgd); |
| 94 | } |
| 95 | #else |
| 96 | /* |
| 97 | * List of all pgd's needed for non-PAE so it can invalidate entries |
| 98 | * in both cached and uncached pgd's; not needed for PAE since the |
| 99 | * kernel pmd is shared. If PAE were not to share the pmd a similar |
| 100 | * tactic would be needed. This is essentially codepath-based locking |
| 101 | * against pageattr.c; it is the unique case in which a valid change |
| 102 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. |
| 103 | * vmalloc faults work because attached pagetables are never freed. |
| 104 | * -- wli |
| 105 | */ |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 106 | #define UNSHARED_PTRS_PER_PGD \ |
| 107 | (SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD) |
| 108 | |
| 109 | static void pgd_ctor(void *p) |
| 110 | { |
| 111 | pgd_t *pgd = p; |
| 112 | unsigned long flags; |
| 113 | |
| 114 | /* Clear usermode parts of PGD */ |
| 115 | memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t)); |
| 116 | |
| 117 | spin_lock_irqsave(&pgd_lock, flags); |
| 118 | |
| 119 | /* If the pgd points to a shared pagetable level (either the |
| 120 | ptes in non-PAE, or shared PMD in PAE), then just copy the |
| 121 | references from swapper_pg_dir. */ |
| 122 | if (PAGETABLE_LEVELS == 2 || |
| 123 | (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) { |
| 124 | clone_pgd_range(pgd + USER_PTRS_PER_PGD, |
| 125 | swapper_pg_dir + USER_PTRS_PER_PGD, |
| 126 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 127 | paravirt_alloc_pmd_clone(__pa(pgd) >> PAGE_SHIFT, |
| 128 | __pa(swapper_pg_dir) >> PAGE_SHIFT, |
| 129 | USER_PTRS_PER_PGD, |
| 130 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 131 | } |
| 132 | |
| 133 | /* list required to sync kernel mapping updates */ |
| 134 | if (!SHARED_KERNEL_PMD) |
| 135 | pgd_list_add(pgd); |
| 136 | |
| 137 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 138 | } |
| 139 | |
| 140 | static void pgd_dtor(void *pgd) |
| 141 | { |
| 142 | unsigned long flags; /* can be called from interrupt context */ |
| 143 | |
| 144 | if (SHARED_KERNEL_PMD) |
| 145 | return; |
| 146 | |
| 147 | spin_lock_irqsave(&pgd_lock, flags); |
| 148 | pgd_list_del(pgd); |
| 149 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 150 | } |
| 151 | |
| 152 | #ifdef CONFIG_X86_PAE |
| 153 | /* |
| 154 | * Mop up any pmd pages which may still be attached to the pgd. |
| 155 | * Normally they will be freed by munmap/exit_mmap, but any pmd we |
| 156 | * preallocate which never got a corresponding vma will need to be |
| 157 | * freed manually. |
| 158 | */ |
| 159 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp) |
| 160 | { |
| 161 | int i; |
| 162 | |
| 163 | for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) { |
| 164 | pgd_t pgd = pgdp[i]; |
| 165 | |
| 166 | if (pgd_val(pgd) != 0) { |
| 167 | pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd); |
| 168 | |
| 169 | pgdp[i] = native_make_pgd(0); |
| 170 | |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 171 | paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 172 | pmd_free(mm, pmd); |
| 173 | } |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * In PAE mode, we need to do a cr3 reload (=tlb flush) when |
| 179 | * updating the top-level pagetable entries to guarantee the |
| 180 | * processor notices the update. Since this is expensive, and |
| 181 | * all 4 top-level entries are used almost immediately in a |
| 182 | * new process's life, we just pre-populate them here. |
| 183 | * |
| 184 | * Also, if we're in a paravirt environment where the kernel pmd is |
| 185 | * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate |
| 186 | * and initialize the kernel pmds here. |
| 187 | */ |
| 188 | static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd) |
| 189 | { |
| 190 | pud_t *pud; |
| 191 | unsigned long addr; |
| 192 | int i; |
| 193 | |
| 194 | pud = pud_offset(pgd, 0); |
| 195 | for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD; |
| 196 | i++, pud++, addr += PUD_SIZE) { |
| 197 | pmd_t *pmd = pmd_alloc_one(mm, addr); |
| 198 | |
| 199 | if (!pmd) { |
| 200 | pgd_mop_up_pmds(mm, pgd); |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | if (i >= USER_PTRS_PER_PGD) |
| 205 | memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]), |
| 206 | sizeof(pmd_t) * PTRS_PER_PMD); |
| 207 | |
| 208 | pud_populate(mm, pud, pmd); |
| 209 | } |
| 210 | |
| 211 | return 1; |
| 212 | } |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 213 | |
| 214 | void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) |
| 215 | { |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 216 | paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 217 | |
| 218 | /* Note: almost everything apart from _PAGE_PRESENT is |
| 219 | reserved at the pmd (PDPT) level. */ |
| 220 | set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT)); |
| 221 | |
| 222 | /* |
| 223 | * According to Intel App note "TLBs, Paging-Structure Caches, |
| 224 | * and Their Invalidation", April 2007, document 317080-001, |
| 225 | * section 8.1: in PAE mode we explicitly have to flush the |
| 226 | * TLB via cr3 if the top-level pgd is changed... |
| 227 | */ |
| 228 | if (mm == current->active_mm) |
| 229 | write_cr3(read_cr3()); |
| 230 | } |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 231 | #else /* !CONFIG_X86_PAE */ |
| 232 | /* No need to prepopulate any pagetable entries in non-PAE modes. */ |
| 233 | static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd) |
| 234 | { |
| 235 | return 1; |
| 236 | } |
| 237 | |
| 238 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgd) |
| 239 | { |
| 240 | } |
| 241 | #endif /* CONFIG_X86_PAE */ |
| 242 | |
| 243 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 244 | { |
| 245 | pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
| 246 | |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 247 | /* so that alloc_pmd can use it */ |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 248 | mm->pgd = pgd; |
| 249 | if (pgd) |
| 250 | pgd_ctor(pgd); |
| 251 | |
| 252 | if (pgd && !pgd_prepopulate_pmd(mm, pgd)) { |
| 253 | pgd_dtor(pgd); |
| 254 | free_page((unsigned long)pgd); |
| 255 | pgd = NULL; |
| 256 | } |
| 257 | |
| 258 | return pgd; |
| 259 | } |
| 260 | |
| 261 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 262 | { |
| 263 | pgd_mop_up_pmds(mm, pgd); |
| 264 | pgd_dtor(pgd); |
| 265 | free_page((unsigned long)pgd); |
| 266 | } |
| 267 | #endif |
Jeremy Fitzhardinge | ee5aa8d | 2008-03-17 16:37:03 -0700 | [diff] [blame] | 268 | |
| 269 | int ptep_set_access_flags(struct vm_area_struct *vma, |
| 270 | unsigned long address, pte_t *ptep, |
| 271 | pte_t entry, int dirty) |
| 272 | { |
| 273 | int changed = !pte_same(*ptep, entry); |
| 274 | |
| 275 | if (changed && dirty) { |
| 276 | *ptep = entry; |
| 277 | pte_update_defer(vma->vm_mm, address, ptep); |
| 278 | flush_tlb_page(vma, address); |
| 279 | } |
| 280 | |
| 281 | return changed; |
| 282 | } |
Jeremy Fitzhardinge | f9fbf1a | 2008-03-17 16:37:04 -0700 | [diff] [blame^] | 283 | |
| 284 | int ptep_test_and_clear_young(struct vm_area_struct *vma, |
| 285 | unsigned long addr, pte_t *ptep) |
| 286 | { |
| 287 | int ret = 0; |
| 288 | |
| 289 | if (pte_young(*ptep)) |
| 290 | ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, |
| 291 | &ptep->pte); |
| 292 | |
| 293 | if (ret) |
| 294 | pte_update(vma->vm_mm, addr, ptep); |
| 295 | |
| 296 | return ret; |
| 297 | } |