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; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 69 | |
| 70 | /* If the pgd points to a shared pagetable level (either the |
| 71 | ptes in non-PAE, or shared PMD in PAE), then just copy the |
| 72 | references from swapper_pg_dir. */ |
| 73 | if (PAGETABLE_LEVELS == 2 || |
Jeremy Fitzhardinge | 85958b4 | 2008-03-17 16:37:14 -0700 | [diff] [blame] | 74 | (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || |
| 75 | PAGETABLE_LEVELS == 4) { |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 76 | clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, |
| 77 | swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 78 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 79 | paravirt_alloc_pmd_clone(__pa(pgd) >> PAGE_SHIFT, |
| 80 | __pa(swapper_pg_dir) >> PAGE_SHIFT, |
Jeremy Fitzhardinge | 68db065 | 2008-03-17 16:37:13 -0700 | [diff] [blame] | 81 | KERNEL_PGD_BOUNDARY, |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 82 | KERNEL_PGD_PTRS); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 83 | } |
| 84 | |
| 85 | /* list required to sync kernel mapping updates */ |
| 86 | if (!SHARED_KERNEL_PMD) |
| 87 | pgd_list_add(pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 88 | } |
| 89 | |
| 90 | static void pgd_dtor(void *pgd) |
| 91 | { |
| 92 | unsigned long flags; /* can be called from interrupt context */ |
| 93 | |
| 94 | if (SHARED_KERNEL_PMD) |
| 95 | return; |
| 96 | |
| 97 | spin_lock_irqsave(&pgd_lock, flags); |
| 98 | pgd_list_del(pgd); |
| 99 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 100 | } |
| 101 | |
Jeremy Fitzhardinge | 85958b4 | 2008-03-17 16:37:14 -0700 | [diff] [blame] | 102 | /* |
| 103 | * List of all pgd's needed for non-PAE so it can invalidate entries |
| 104 | * in both cached and uncached pgd's; not needed for PAE since the |
| 105 | * kernel pmd is shared. If PAE were not to share the pmd a similar |
| 106 | * tactic would be needed. This is essentially codepath-based locking |
| 107 | * against pageattr.c; it is the unique case in which a valid change |
| 108 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. |
| 109 | * vmalloc faults work because attached pagetables are never freed. |
| 110 | * -- wli |
| 111 | */ |
| 112 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 113 | #ifdef CONFIG_X86_PAE |
| 114 | /* |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 115 | * In PAE mode, we need to do a cr3 reload (=tlb flush) when |
| 116 | * updating the top-level pagetable entries to guarantee the |
| 117 | * processor notices the update. Since this is expensive, and |
| 118 | * all 4 top-level entries are used almost immediately in a |
| 119 | * new process's life, we just pre-populate them here. |
| 120 | * |
| 121 | * Also, if we're in a paravirt environment where the kernel pmd is |
| 122 | * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate |
| 123 | * and initialize the kernel pmds here. |
| 124 | */ |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 125 | #define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 126 | |
| 127 | void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) |
| 128 | { |
Jeremy Fitzhardinge | 6944a9c | 2008-03-17 16:37:01 -0700 | [diff] [blame] | 129 | paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); |
Ingo Molnar | 1ec1fe7 | 2008-03-19 20:30:40 +0100 | [diff] [blame] | 130 | |
| 131 | /* Note: almost everything apart from _PAGE_PRESENT is |
| 132 | reserved at the pmd (PDPT) level. */ |
| 133 | set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT)); |
| 134 | |
| 135 | /* |
| 136 | * According to Intel App note "TLBs, Paging-Structure Caches, |
| 137 | * and Their Invalidation", April 2007, document 317080-001, |
| 138 | * section 8.1: in PAE mode we explicitly have to flush the |
| 139 | * TLB via cr3 if the top-level pgd is changed... |
| 140 | */ |
| 141 | if (mm == current->active_mm) |
| 142 | write_cr3(read_cr3()); |
| 143 | } |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 144 | #else /* !CONFIG_X86_PAE */ |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 145 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 146 | /* No need to prepopulate any pagetable entries in non-PAE modes. */ |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 147 | #define PREALLOCATED_PMDS 0 |
| 148 | |
| 149 | #endif /* CONFIG_X86_PAE */ |
| 150 | |
| 151 | static void free_pmds(pmd_t *pmds[]) |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 152 | { |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 153 | int i; |
| 154 | |
| 155 | for(i = 0; i < PREALLOCATED_PMDS; i++) |
| 156 | if (pmds[i]) |
| 157 | free_page((unsigned long)pmds[i]); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 158 | } |
| 159 | |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 160 | static int preallocate_pmds(pmd_t *pmds[]) |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 161 | { |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 162 | int i; |
| 163 | bool failed = false; |
| 164 | |
| 165 | for(i = 0; i < PREALLOCATED_PMDS; i++) { |
| 166 | pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT); |
| 167 | if (pmd == NULL) |
| 168 | failed = true; |
| 169 | pmds[i] = pmd; |
| 170 | } |
| 171 | |
| 172 | if (failed) { |
| 173 | free_pmds(pmds); |
| 174 | return -ENOMEM; |
| 175 | } |
| 176 | |
| 177 | return 0; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 178 | } |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 179 | |
| 180 | /* |
| 181 | * Mop up any pmd pages which may still be attached to the pgd. |
| 182 | * Normally they will be freed by munmap/exit_mmap, but any pmd we |
| 183 | * preallocate which never got a corresponding vma will need to be |
| 184 | * freed manually. |
| 185 | */ |
| 186 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp) |
| 187 | { |
| 188 | int i; |
| 189 | |
| 190 | for(i = 0; i < PREALLOCATED_PMDS; i++) { |
| 191 | pgd_t pgd = pgdp[i]; |
| 192 | |
| 193 | if (pgd_val(pgd) != 0) { |
| 194 | pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd); |
| 195 | |
| 196 | pgdp[i] = native_make_pgd(0); |
| 197 | |
| 198 | paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT); |
| 199 | pmd_free(mm, pmd); |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[]) |
| 205 | { |
| 206 | pud_t *pud; |
| 207 | unsigned long addr; |
| 208 | int i; |
| 209 | |
| 210 | pud = pud_offset(pgd, 0); |
| 211 | |
| 212 | for (addr = i = 0; i < PREALLOCATED_PMDS; |
| 213 | i++, pud++, addr += PUD_SIZE) { |
| 214 | pmd_t *pmd = pmds[i]; |
| 215 | |
| 216 | if (i >= KERNEL_PGD_BOUNDARY) |
| 217 | memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]), |
| 218 | sizeof(pmd_t) * PTRS_PER_PMD); |
| 219 | |
| 220 | pud_populate(mm, pud, pmd); |
| 221 | } |
| 222 | } |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 223 | |
| 224 | pgd_t *pgd_alloc(struct mm_struct *mm) |
| 225 | { |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 226 | pgd_t *pgd; |
| 227 | pmd_t *pmds[PREALLOCATED_PMDS]; |
| 228 | unsigned long flags; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 229 | |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 230 | pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
| 231 | |
| 232 | if (pgd == NULL) |
| 233 | goto out; |
| 234 | |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 235 | mm->pgd = pgd; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 236 | |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 237 | if (preallocate_pmds(pmds) != 0) |
| 238 | goto out_free_pgd; |
| 239 | |
| 240 | if (paravirt_pgd_alloc(mm) != 0) |
| 241 | goto out_free_pmds; |
| 242 | |
| 243 | /* |
| 244 | * Make sure that pre-populating the pmds is atomic with |
| 245 | * respect to anything walking the pgd_list, so that they |
| 246 | * never see a partially populated pgd. |
| 247 | */ |
| 248 | spin_lock_irqsave(&pgd_lock, flags); |
| 249 | |
| 250 | pgd_ctor(pgd); |
| 251 | pgd_prepopulate_pmd(mm, pgd, pmds); |
| 252 | |
| 253 | spin_unlock_irqrestore(&pgd_lock, flags); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 254 | |
| 255 | return pgd; |
Jeremy Fitzhardinge | d8d5900 | 2008-06-25 00:19:13 -0400 | [diff] [blame^] | 256 | |
| 257 | out_free_pmds: |
| 258 | free_pmds(pmds); |
| 259 | out_free_pgd: |
| 260 | free_page((unsigned long)pgd); |
| 261 | out: |
| 262 | return NULL; |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 263 | } |
| 264 | |
| 265 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) |
| 266 | { |
| 267 | pgd_mop_up_pmds(mm, pgd); |
| 268 | pgd_dtor(pgd); |
Jeremy Fitzhardinge | eba0045 | 2008-06-25 00:19:12 -0400 | [diff] [blame] | 269 | paravirt_pgd_free(mm, pgd); |
Jeremy Fitzhardinge | 4f76cd3 | 2008-03-17 16:36:55 -0700 | [diff] [blame] | 270 | free_page((unsigned long)pgd); |
| 271 | } |
Jeremy Fitzhardinge | ee5aa8d | 2008-03-17 16:37:03 -0700 | [diff] [blame] | 272 | |
| 273 | int ptep_set_access_flags(struct vm_area_struct *vma, |
| 274 | unsigned long address, pte_t *ptep, |
| 275 | pte_t entry, int dirty) |
| 276 | { |
| 277 | int changed = !pte_same(*ptep, entry); |
| 278 | |
| 279 | if (changed && dirty) { |
| 280 | *ptep = entry; |
| 281 | pte_update_defer(vma->vm_mm, address, ptep); |
| 282 | flush_tlb_page(vma, address); |
| 283 | } |
| 284 | |
| 285 | return changed; |
| 286 | } |
Jeremy Fitzhardinge | f9fbf1a | 2008-03-17 16:37:04 -0700 | [diff] [blame] | 287 | |
| 288 | int ptep_test_and_clear_young(struct vm_area_struct *vma, |
| 289 | unsigned long addr, pte_t *ptep) |
| 290 | { |
| 291 | int ret = 0; |
| 292 | |
| 293 | if (pte_young(*ptep)) |
| 294 | ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, |
Thomas Gleixner | 48e2395 | 2008-05-24 17:24:34 +0200 | [diff] [blame] | 295 | (unsigned long *) &ptep->pte); |
Jeremy Fitzhardinge | f9fbf1a | 2008-03-17 16:37:04 -0700 | [diff] [blame] | 296 | |
| 297 | if (ret) |
| 298 | pte_update(vma->vm_mm, addr, ptep); |
| 299 | |
| 300 | return ret; |
| 301 | } |
Jeremy Fitzhardinge | c20311e | 2008-03-17 16:37:05 -0700 | [diff] [blame] | 302 | |
| 303 | int ptep_clear_flush_young(struct vm_area_struct *vma, |
| 304 | unsigned long address, pte_t *ptep) |
| 305 | { |
| 306 | int young; |
| 307 | |
| 308 | young = ptep_test_and_clear_young(vma, address, ptep); |
| 309 | if (young) |
| 310 | flush_tlb_page(vma, address); |
| 311 | |
| 312 | return young; |
| 313 | } |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 314 | |
| 315 | int fixmaps_set; |
| 316 | |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 317 | void __native_set_fixmap(enum fixed_addresses idx, pte_t pte) |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 318 | { |
| 319 | unsigned long address = __fix_to_virt(idx); |
| 320 | |
| 321 | if (idx >= __end_of_fixed_addresses) { |
| 322 | BUG(); |
| 323 | return; |
| 324 | } |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 325 | set_pte_vaddr(address, pte); |
Jeremy Fitzhardinge | 7c7e6e0 | 2008-06-17 11:41:54 -0700 | [diff] [blame] | 326 | fixmaps_set++; |
| 327 | } |
Jeremy Fitzhardinge | aeaaa59 | 2008-06-17 11:42:01 -0700 | [diff] [blame] | 328 | |
| 329 | void native_set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags) |
| 330 | { |
| 331 | __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags)); |
| 332 | } |