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> |
Ingo Molnar | a1d5a86 | 2008-06-20 15:34:46 +0200 | [diff] [blame] | 5 | #include <asm/fixmap.h> |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 6 | |
| 7 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) |
| 8 | { |
| 9 | return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); |
| 10 | } |
| 11 | |
| 12 | pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) |
| 13 | { |
| 14 | struct page *pte; |
| 15 | |
| 16 | #ifdef CONFIG_HIGHPTE |
| 17 | pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0); |
| 18 | #else |
| 19 | pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0); |
| 20 | #endif |
| 21 | if (pte) |
| 22 | pgtable_page_ctor(pte); |
| 23 | return pte; |
| 24 | } |
| 25 | |
Jeremy Fitzhardinge | 397f687 | 2008-03-17 16:36:57 -0700 | [diff] [blame] | 26 | void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte) |
| 27 | { |
| 28 | pgtable_page_dtor(pte); |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 29 | paravirt_release_pte(page_to_pfn(pte)); |
Jeremy Fitzhardinge | 397f687 | 2008-03-17 16:36:57 -0700 | [diff] [blame] | 30 | tlb_remove_page(tlb, pte); |
| 31 | } |
| 32 | |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 33 | #if PAGETABLE_LEVELS > 2 |
| 34 | void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) |
| 35 | { |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 36 | paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 37 | tlb_remove_page(tlb, virt_to_page(pmd)); |
| 38 | } |
Jeremy Fitzhardinge | 5a5f8f4 | 2008-03-17 16:36:59 -0700 | [diff] [blame] | 39 | |
| 40 | #if PAGETABLE_LEVELS > 3 |
| 41 | void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) |
| 42 | { |
Jeremy Fitzhardinge | 2761fa0 | 2008-03-17 16:37:02 -0700 | [diff] [blame] | 43 | paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 5a5f8f4 | 2008-03-17 16:36:59 -0700 | [diff] [blame] | 44 | tlb_remove_page(tlb, virt_to_page(pud)); |
| 45 | } |
| 46 | #endif /* PAGETABLE_LEVELS > 3 */ |
Jeremy Fitzhardinge | 170fdff | 2008-03-17 16:36:58 -0700 | [diff] [blame] | 47 | #endif /* PAGETABLE_LEVELS > 2 */ |
| 48 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 49 | static inline void pgd_list_add(pgd_t *pgd) |
| 50 | { |
| 51 | struct page *page = virt_to_page(pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 52 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 53 | list_add(&page->lru, &pgd_list); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 54 | } |
| 55 | |
| 56 | static inline void pgd_list_del(pgd_t *pgd) |
| 57 | { |
| 58 | struct page *page = virt_to_page(pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 59 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 60 | list_del(&page->lru); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 61 | } |
| 62 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 63 | #define UNSHARED_PTRS_PER_PGD \ |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 64 | (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD) |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 65 | |
| 66 | static void pgd_ctor(void *p) |
| 67 | { |
| 68 | pgd_t *pgd = p; |
| 69 | unsigned long flags; |
| 70 | |
| 71 | /* Clear usermode parts of PGD */ |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 72 | memset(pgd, 0, KERNEL_PGD_BOUNDARY*sizeof(pgd_t)); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 73 | |
| 74 | spin_lock_irqsave(&pgd_lock, flags); |
| 75 | |
| 76 | /* If the pgd points to a shared pagetable level (either the |
| 77 | ptes in non-PAE, or shared PMD in PAE), then just copy the |
| 78 | references from swapper_pg_dir. */ |
| 79 | if (PAGETABLE_LEVELS == 2 || |
Jeremy Fitzhardinge | 85958b4 | 2008-03-17 16:37:14 -0700 | [diff] [blame] | 80 | (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || |
| 81 | PAGETABLE_LEVELS == 4) { |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 82 | clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, |
| 83 | swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 84 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 85 | paravirt_alloc_pmd_clone(__pa(pgd) >> PAGE_SHIFT, |
| 86 | __pa(swapper_pg_dir) >> PAGE_SHIFT, |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 87 | KERNEL_PGD_BOUNDARY, |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 88 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 89 | } |
| 90 | |
| 91 | /* list required to sync kernel mapping updates */ |
| 92 | if (!SHARED_KERNEL_PMD) |
| 93 | pgd_list_add(pgd); |
| 94 | |
| 95 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 96 | } |
| 97 | |
| 98 | static void pgd_dtor(void *pgd) |
| 99 | { |
| 100 | unsigned long flags; /* can be called from interrupt context */ |
| 101 | |
| 102 | if (SHARED_KERNEL_PMD) |
| 103 | return; |
| 104 | |
| 105 | spin_lock_irqsave(&pgd_lock, flags); |
| 106 | pgd_list_del(pgd); |
| 107 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 108 | } |
| 109 | |
Jeremy Fitzhardinge | 85958b4 | 2008-03-17 16:37:14 -0700 | [diff] [blame] | 110 | /* |
| 111 | * List of all pgd's needed for non-PAE so it can invalidate entries |
| 112 | * in both cached and uncached pgd's; not needed for PAE since the |
| 113 | * kernel pmd is shared. If PAE were not to share the pmd a similar |
| 114 | * tactic would be needed. This is essentially codepath-based locking |
| 115 | * against pageattr.c; it is the unique case in which a valid change |
| 116 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. |
| 117 | * vmalloc faults work because attached pagetables are never freed. |
| 118 | * -- wli |
| 119 | */ |
| 120 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 121 | #ifdef CONFIG_X86_PAE |
| 122 | /* |
| 123 | * Mop up any pmd pages which may still be attached to the pgd. |
| 124 | * Normally they will be freed by munmap/exit_mmap, but any pmd we |
| 125 | * preallocate which never got a corresponding vma will need to be |
| 126 | * freed manually. |
| 127 | */ |
| 128 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp) |
| 129 | { |
| 130 | int i; |
| 131 | |
| 132 | for(i = 0; i < UNSHARED_PTRS_PER_PGD; i++) { |
| 133 | pgd_t pgd = pgdp[i]; |
| 134 | |
| 135 | if (pgd_val(pgd) != 0) { |
| 136 | pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd); |
| 137 | |
| 138 | pgdp[i] = native_make_pgd(0); |
| 139 | |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 140 | paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 141 | pmd_free(mm, pmd); |
| 142 | } |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | /* |
| 147 | * In PAE mode, we need to do a cr3 reload (=tlb flush) when |
| 148 | * updating the top-level pagetable entries to guarantee the |
| 149 | * processor notices the update. Since this is expensive, and |
| 150 | * all 4 top-level entries are used almost immediately in a |
| 151 | * new process's life, we just pre-populate them here. |
| 152 | * |
| 153 | * Also, if we're in a paravirt environment where the kernel pmd is |
| 154 | * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate |
| 155 | * and initialize the kernel pmds here. |
| 156 | */ |
| 157 | static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd) |
| 158 | { |
| 159 | pud_t *pud; |
| 160 | unsigned long addr; |
| 161 | int i; |
| 162 | |
| 163 | pud = pud_offset(pgd, 0); |
| 164 | for (addr = i = 0; i < UNSHARED_PTRS_PER_PGD; |
| 165 | i++, pud++, addr += PUD_SIZE) { |
| 166 | pmd_t *pmd = pmd_alloc_one(mm, addr); |
| 167 | |
| 168 | if (!pmd) { |
| 169 | pgd_mop_up_pmds(mm, pgd); |
| 170 | return 0; |
| 171 | } |
| 172 | |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 173 | if (i >= KERNEL_PGD_BOUNDARY) |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 174 | memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]), |
| 175 | sizeof(pmd_t) * PTRS_PER_PMD); |
| 176 | |
| 177 | pud_populate(mm, pud, pmd); |
| 178 | } |
| 179 | |
| 180 | return 1; |
| 181 | } |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 182 | |
| 183 | void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) |
| 184 | { |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 185 | paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 186 | |
| 187 | /* Note: almost everything apart from _PAGE_PRESENT is |
| 188 | reserved at the pmd (PDPT) level. */ |
| 189 | set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT)); |
| 190 | |
| 191 | /* |
| 192 | * According to Intel App note "TLBs, Paging-Structure Caches, |
| 193 | * and Their Invalidation", April 2007, document 317080-001, |
| 194 | * section 8.1: in PAE mode we explicitly have to flush the |
| 195 | * TLB via cr3 if the top-level pgd is changed... |
| 196 | */ |
| 197 | if (mm == current->active_mm) |
| 198 | write_cr3(read_cr3()); |
| 199 | } |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 200 | #else /* !CONFIG_X86_PAE */ |
| 201 | /* No need to prepopulate any pagetable entries in non-PAE modes. */ |
| 202 | static int pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd) |
| 203 | { |
| 204 | return 1; |
| 205 | } |
| 206 | |
| 207 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgd) |
| 208 | { |
| 209 | } |
| 210 | #endif /* CONFIG_X86_PAE */ |
| 211 | |
| 212 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 213 | { |
| 214 | pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
| 215 | |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 216 | /* so that alloc_pmd can use it */ |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 217 | mm->pgd = pgd; |
Jeremy Fitzhardinge | eba0045 | 2008-06-25 00:19:12 -0400 | [diff] [blame^] | 218 | if (pgd) { |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 219 | pgd_ctor(pgd); |
| 220 | |
Jeremy Fitzhardinge | eba0045 | 2008-06-25 00:19:12 -0400 | [diff] [blame^] | 221 | if (paravirt_pgd_alloc(mm) != 0 || |
| 222 | !pgd_prepopulate_pmd(mm, pgd)) { |
| 223 | pgd_dtor(pgd); |
| 224 | free_page((unsigned long)pgd); |
| 225 | pgd = NULL; |
| 226 | } |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 227 | } |
| 228 | |
| 229 | return pgd; |
| 230 | } |
| 231 | |
| 232 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 233 | { |
| 234 | pgd_mop_up_pmds(mm, pgd); |
| 235 | pgd_dtor(pgd); |
Jeremy Fitzhardinge | eba0045 | 2008-06-25 00:19:12 -0400 | [diff] [blame^] | 236 | paravirt_pgd_free(mm, pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 237 | free_page((unsigned long)pgd); |
| 238 | } |
Jeremy Fitzhardinge | ee5aa8d | 2008-03-17 16:37:03 -0700 | [diff] [blame] | 239 | |
| 240 | int ptep_set_access_flags(struct vm_area_struct *vma, |
| 241 | unsigned long address, pte_t *ptep, |
| 242 | pte_t entry, int dirty) |
| 243 | { |
| 244 | int changed = !pte_same(*ptep, entry); |
| 245 | |
| 246 | if (changed && dirty) { |
| 247 | *ptep = entry; |
| 248 | pte_update_defer(vma->vm_mm, address, ptep); |
| 249 | flush_tlb_page(vma, address); |
| 250 | } |
| 251 | |
| 252 | return changed; |
| 253 | } |
Jeremy Fitzhardinge | f9fbf1a | 2008-03-17 16:37:04 -0700 | [diff] [blame] | 254 | |
| 255 | int ptep_test_and_clear_young(struct vm_area_struct *vma, |
| 256 | unsigned long addr, pte_t *ptep) |
| 257 | { |
| 258 | int ret = 0; |
| 259 | |
| 260 | if (pte_young(*ptep)) |
| 261 | ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, |
Thomas Gleixner | 48e2395 | 2008-05-24 17:24:34 +0200 | [diff] [blame] | 262 | (unsigned long *) &ptep->pte); |
Jeremy Fitzhardinge | f9fbf1a | 2008-03-17 16:37:04 -0700 | [diff] [blame] | 263 | |
| 264 | if (ret) |
| 265 | pte_update(vma->vm_mm, addr, ptep); |
| 266 | |
| 267 | return ret; |
| 268 | } |
Jeremy Fitzhardinge | c20311e | 2008-03-17 16:37:05 -0700 | [diff] [blame] | 269 | |
| 270 | int ptep_clear_flush_young(struct vm_area_struct *vma, |
| 271 | unsigned long address, pte_t *ptep) |
| 272 | { |
| 273 | int young; |
| 274 | |
| 275 | young = ptep_test_and_clear_young(vma, address, ptep); |
| 276 | if (young) |
| 277 | flush_tlb_page(vma, address); |
| 278 | |
| 279 | return young; |
| 280 | } |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 281 | |
| 282 | int fixmaps_set; |
| 283 | |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 284 | void __native_set_fixmap(enum fixed_addresses idx, pte_t pte) |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 285 | { |
| 286 | unsigned long address = __fix_to_virt(idx); |
| 287 | |
| 288 | if (idx >= __end_of_fixed_addresses) { |
| 289 | BUG(); |
| 290 | return; |
| 291 | } |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 292 | set_pte_vaddr(address, pte); |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 293 | fixmaps_set++; |
| 294 | } |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 295 | |
| 296 | void native_set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags) |
| 297 | { |
| 298 | __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags)); |
| 299 | } |