Commit | Line | Data |
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4f76cd38 JF |
1 | #include <linux/mm.h> |
2 | #include <asm/pgalloc.h> | |
ee5aa8d3 | 3 | #include <asm/pgtable.h> |
4f76cd38 | 4 | #include <asm/tlb.h> |
a1d5a869 | 5 | #include <asm/fixmap.h> |
4f76cd38 JF |
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 | ||
397f687a JF |
26 | void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte) |
27 | { | |
28 | pgtable_page_dtor(pte); | |
6944a9c8 | 29 | paravirt_release_pte(page_to_pfn(pte)); |
397f687a JF |
30 | tlb_remove_page(tlb, pte); |
31 | } | |
32 | ||
170fdff7 JF |
33 | #if PAGETABLE_LEVELS > 2 |
34 | void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) | |
35 | { | |
6944a9c8 | 36 | paravirt_release_pmd(__pa(pmd) >> PAGE_SHIFT); |
170fdff7 JF |
37 | tlb_remove_page(tlb, virt_to_page(pmd)); |
38 | } | |
5a5f8f42 JF |
39 | |
40 | #if PAGETABLE_LEVELS > 3 | |
41 | void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) | |
42 | { | |
2761fa09 | 43 | paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); |
5a5f8f42 JF |
44 | tlb_remove_page(tlb, virt_to_page(pud)); |
45 | } | |
46 | #endif /* PAGETABLE_LEVELS > 3 */ | |
170fdff7 JF |
47 | #endif /* PAGETABLE_LEVELS > 2 */ |
48 | ||
4f76cd38 JF |
49 | static inline void pgd_list_add(pgd_t *pgd) |
50 | { | |
51 | struct page *page = virt_to_page(pgd); | |
4f76cd38 | 52 | |
4f76cd38 | 53 | list_add(&page->lru, &pgd_list); |
4f76cd38 JF |
54 | } |
55 | ||
56 | static inline void pgd_list_del(pgd_t *pgd) | |
57 | { | |
58 | struct page *page = virt_to_page(pgd); | |
4f76cd38 | 59 | |
4f76cd38 | 60 | list_del(&page->lru); |
4f76cd38 JF |
61 | } |
62 | ||
4f76cd38 | 63 | #define UNSHARED_PTRS_PER_PGD \ |
68db065c | 64 | (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD) |
4f76cd38 | 65 | |
17b74627 | 66 | static void pgd_ctor(pgd_t *pgd) |
4f76cd38 | 67 | { |
4f76cd38 JF |
68 | /* If the pgd points to a shared pagetable level (either the |
69 | ptes in non-PAE, or shared PMD in PAE), then just copy the | |
70 | references from swapper_pg_dir. */ | |
71 | if (PAGETABLE_LEVELS == 2 || | |
85958b46 JF |
72 | (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) || |
73 | PAGETABLE_LEVELS == 4) { | |
68db065c JF |
74 | clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY, |
75 | swapper_pg_dir + KERNEL_PGD_BOUNDARY, | |
4f76cd38 | 76 | KERNEL_PGD_PTRS); |
6944a9c8 JF |
77 | paravirt_alloc_pmd_clone(__pa(pgd) >> PAGE_SHIFT, |
78 | __pa(swapper_pg_dir) >> PAGE_SHIFT, | |
68db065c | 79 | KERNEL_PGD_BOUNDARY, |
6944a9c8 | 80 | KERNEL_PGD_PTRS); |
4f76cd38 JF |
81 | } |
82 | ||
83 | /* list required to sync kernel mapping updates */ | |
84 | if (!SHARED_KERNEL_PMD) | |
85 | pgd_list_add(pgd); | |
4f76cd38 JF |
86 | } |
87 | ||
17b74627 | 88 | static void pgd_dtor(pgd_t *pgd) |
4f76cd38 JF |
89 | { |
90 | unsigned long flags; /* can be called from interrupt context */ | |
91 | ||
92 | if (SHARED_KERNEL_PMD) | |
93 | return; | |
94 | ||
95 | spin_lock_irqsave(&pgd_lock, flags); | |
96 | pgd_list_del(pgd); | |
97 | spin_unlock_irqrestore(&pgd_lock, flags); | |
98 | } | |
99 | ||
85958b46 JF |
100 | /* |
101 | * List of all pgd's needed for non-PAE so it can invalidate entries | |
102 | * in both cached and uncached pgd's; not needed for PAE since the | |
103 | * kernel pmd is shared. If PAE were not to share the pmd a similar | |
104 | * tactic would be needed. This is essentially codepath-based locking | |
105 | * against pageattr.c; it is the unique case in which a valid change | |
106 | * of kernel pagetables can't be lazily synchronized by vmalloc faults. | |
107 | * vmalloc faults work because attached pagetables are never freed. | |
108 | * -- wli | |
109 | */ | |
110 | ||
4f76cd38 | 111 | #ifdef CONFIG_X86_PAE |
d8d5900e JF |
112 | /* |
113 | * In PAE mode, we need to do a cr3 reload (=tlb flush) when | |
114 | * updating the top-level pagetable entries to guarantee the | |
115 | * processor notices the update. Since this is expensive, and | |
116 | * all 4 top-level entries are used almost immediately in a | |
117 | * new process's life, we just pre-populate them here. | |
118 | * | |
119 | * Also, if we're in a paravirt environment where the kernel pmd is | |
120 | * not shared between pagetables (!SHARED_KERNEL_PMDS), we allocate | |
121 | * and initialize the kernel pmds here. | |
122 | */ | |
123 | #define PREALLOCATED_PMDS UNSHARED_PTRS_PER_PGD | |
124 | ||
125 | void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) | |
126 | { | |
127 | paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); | |
128 | ||
129 | /* Note: almost everything apart from _PAGE_PRESENT is | |
130 | reserved at the pmd (PDPT) level. */ | |
131 | set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT)); | |
132 | ||
133 | /* | |
134 | * According to Intel App note "TLBs, Paging-Structure Caches, | |
135 | * and Their Invalidation", April 2007, document 317080-001, | |
136 | * section 8.1: in PAE mode we explicitly have to flush the | |
137 | * TLB via cr3 if the top-level pgd is changed... | |
138 | */ | |
139 | if (mm == current->active_mm) | |
140 | write_cr3(read_cr3()); | |
141 | } | |
142 | #else /* !CONFIG_X86_PAE */ | |
143 | ||
144 | /* No need to prepopulate any pagetable entries in non-PAE modes. */ | |
145 | #define PREALLOCATED_PMDS 0 | |
146 | ||
147 | #endif /* CONFIG_X86_PAE */ | |
148 | ||
149 | static void free_pmds(pmd_t *pmds[]) | |
150 | { | |
151 | int i; | |
152 | ||
153 | for(i = 0; i < PREALLOCATED_PMDS; i++) | |
154 | if (pmds[i]) | |
155 | free_page((unsigned long)pmds[i]); | |
156 | } | |
157 | ||
158 | static int preallocate_pmds(pmd_t *pmds[]) | |
159 | { | |
160 | int i; | |
161 | bool failed = false; | |
162 | ||
163 | for(i = 0; i < PREALLOCATED_PMDS; i++) { | |
164 | pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT); | |
165 | if (pmd == NULL) | |
166 | failed = true; | |
167 | pmds[i] = pmd; | |
168 | } | |
169 | ||
170 | if (failed) { | |
171 | free_pmds(pmds); | |
172 | return -ENOMEM; | |
173 | } | |
174 | ||
175 | return 0; | |
176 | } | |
177 | ||
4f76cd38 JF |
178 | /* |
179 | * Mop up any pmd pages which may still be attached to the pgd. | |
180 | * Normally they will be freed by munmap/exit_mmap, but any pmd we | |
181 | * preallocate which never got a corresponding vma will need to be | |
182 | * freed manually. | |
183 | */ | |
184 | static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp) | |
185 | { | |
186 | int i; | |
187 | ||
d8d5900e | 188 | for(i = 0; i < PREALLOCATED_PMDS; i++) { |
4f76cd38 JF |
189 | pgd_t pgd = pgdp[i]; |
190 | ||
191 | if (pgd_val(pgd) != 0) { | |
192 | pmd_t *pmd = (pmd_t *)pgd_page_vaddr(pgd); | |
193 | ||
194 | pgdp[i] = native_make_pgd(0); | |
195 | ||
6944a9c8 | 196 | paravirt_release_pmd(pgd_val(pgd) >> PAGE_SHIFT); |
4f76cd38 JF |
197 | pmd_free(mm, pmd); |
198 | } | |
199 | } | |
200 | } | |
201 | ||
d8d5900e | 202 | static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[]) |
4f76cd38 JF |
203 | { |
204 | pud_t *pud; | |
205 | unsigned long addr; | |
206 | int i; | |
207 | ||
cf3e5050 JF |
208 | if (PREALLOCATED_PMDS == 0) /* Work around gcc-3.4.x bug */ |
209 | return; | |
210 | ||
4f76cd38 | 211 | pud = pud_offset(pgd, 0); |
4f76cd38 | 212 | |
d8d5900e JF |
213 | for (addr = i = 0; i < PREALLOCATED_PMDS; |
214 | i++, pud++, addr += PUD_SIZE) { | |
215 | pmd_t *pmd = pmds[i]; | |
4f76cd38 | 216 | |
68db065c | 217 | if (i >= KERNEL_PGD_BOUNDARY) |
4f76cd38 JF |
218 | memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]), |
219 | sizeof(pmd_t) * PTRS_PER_PMD); | |
220 | ||
221 | pud_populate(mm, pud, pmd); | |
222 | } | |
4f76cd38 | 223 | } |
1ec1fe73 | 224 | |
d8d5900e | 225 | pgd_t *pgd_alloc(struct mm_struct *mm) |
1ec1fe73 | 226 | { |
d8d5900e JF |
227 | pgd_t *pgd; |
228 | pmd_t *pmds[PREALLOCATED_PMDS]; | |
229 | unsigned long flags; | |
1ec1fe73 | 230 | |
d8d5900e JF |
231 | pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
232 | ||
233 | if (pgd == NULL) | |
234 | goto out; | |
235 | ||
236 | mm->pgd = pgd; | |
237 | ||
238 | if (preallocate_pmds(pmds) != 0) | |
239 | goto out_free_pgd; | |
240 | ||
241 | if (paravirt_pgd_alloc(mm) != 0) | |
242 | goto out_free_pmds; | |
1ec1fe73 IM |
243 | |
244 | /* | |
d8d5900e JF |
245 | * Make sure that pre-populating the pmds is atomic with |
246 | * respect to anything walking the pgd_list, so that they | |
247 | * never see a partially populated pgd. | |
1ec1fe73 | 248 | */ |
d8d5900e | 249 | spin_lock_irqsave(&pgd_lock, flags); |
4f76cd38 | 250 | |
d8d5900e JF |
251 | pgd_ctor(pgd); |
252 | pgd_prepopulate_pmd(mm, pgd, pmds); | |
4f76cd38 | 253 | |
d8d5900e | 254 | spin_unlock_irqrestore(&pgd_lock, flags); |
4f76cd38 JF |
255 | |
256 | return pgd; | |
d8d5900e JF |
257 | |
258 | out_free_pmds: | |
259 | free_pmds(pmds); | |
260 | out_free_pgd: | |
261 | free_page((unsigned long)pgd); | |
262 | out: | |
263 | return NULL; | |
4f76cd38 JF |
264 | } |
265 | ||
266 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) | |
267 | { | |
268 | pgd_mop_up_pmds(mm, pgd); | |
269 | pgd_dtor(pgd); | |
eba0045f | 270 | paravirt_pgd_free(mm, pgd); |
4f76cd38 JF |
271 | free_page((unsigned long)pgd); |
272 | } | |
ee5aa8d3 JF |
273 | |
274 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
275 | unsigned long address, pte_t *ptep, | |
276 | pte_t entry, int dirty) | |
277 | { | |
278 | int changed = !pte_same(*ptep, entry); | |
279 | ||
280 | if (changed && dirty) { | |
281 | *ptep = entry; | |
282 | pte_update_defer(vma->vm_mm, address, ptep); | |
283 | flush_tlb_page(vma, address); | |
284 | } | |
285 | ||
286 | return changed; | |
287 | } | |
f9fbf1a3 JF |
288 | |
289 | int ptep_test_and_clear_young(struct vm_area_struct *vma, | |
290 | unsigned long addr, pte_t *ptep) | |
291 | { | |
292 | int ret = 0; | |
293 | ||
294 | if (pte_young(*ptep)) | |
295 | ret = test_and_clear_bit(_PAGE_BIT_ACCESSED, | |
48e23957 | 296 | (unsigned long *) &ptep->pte); |
f9fbf1a3 JF |
297 | |
298 | if (ret) | |
299 | pte_update(vma->vm_mm, addr, ptep); | |
300 | ||
301 | return ret; | |
302 | } | |
c20311e1 JF |
303 | |
304 | int ptep_clear_flush_young(struct vm_area_struct *vma, | |
305 | unsigned long address, pte_t *ptep) | |
306 | { | |
307 | int young; | |
308 | ||
309 | young = ptep_test_and_clear_young(vma, address, ptep); | |
310 | if (young) | |
311 | flush_tlb_page(vma, address); | |
312 | ||
313 | return young; | |
314 | } | |
7c7e6e07 JF |
315 | |
316 | int fixmaps_set; | |
317 | ||
aeaaa59c | 318 | void __native_set_fixmap(enum fixed_addresses idx, pte_t pte) |
7c7e6e07 JF |
319 | { |
320 | unsigned long address = __fix_to_virt(idx); | |
321 | ||
322 | if (idx >= __end_of_fixed_addresses) { | |
323 | BUG(); | |
324 | return; | |
325 | } | |
aeaaa59c | 326 | set_pte_vaddr(address, pte); |
7c7e6e07 JF |
327 | fixmaps_set++; |
328 | } | |
aeaaa59c JF |
329 | |
330 | void native_set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags) | |
331 | { | |
332 | __native_set_fixmap(idx, pfn_pte(phys >> PAGE_SHIFT, flags)); | |
333 | } |