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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
3 | * (C) William Irwin, April 2004 | |
4 | */ | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/list.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
1da177e4 LT |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> | |
12 | #include <linux/nodemask.h> | |
63551ae0 | 13 | #include <linux/pagemap.h> |
5da7ca86 | 14 | #include <linux/mempolicy.h> |
aea47ff3 | 15 | #include <linux/cpuset.h> |
3935baa9 | 16 | #include <linux/mutex.h> |
5da7ca86 | 17 | |
63551ae0 DG |
18 | #include <asm/page.h> |
19 | #include <asm/pgtable.h> | |
20 | ||
21 | #include <linux/hugetlb.h> | |
7835e98b | 22 | #include "internal.h" |
1da177e4 LT |
23 | |
24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
a43a8c39 | 25 | static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; |
1da177e4 LT |
26 | unsigned long max_huge_pages; |
27 | static struct list_head hugepage_freelists[MAX_NUMNODES]; | |
28 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; | |
29 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; | |
3935baa9 DG |
30 | /* |
31 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
32 | */ | |
33 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 34 | |
79ac6ba4 DG |
35 | static void clear_huge_page(struct page *page, unsigned long addr) |
36 | { | |
37 | int i; | |
38 | ||
39 | might_sleep(); | |
40 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
41 | cond_resched(); | |
42 | clear_user_highpage(page + i, addr); | |
43 | } | |
44 | } | |
45 | ||
46 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 47 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
48 | { |
49 | int i; | |
50 | ||
51 | might_sleep(); | |
52 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
53 | cond_resched(); | |
9de455b2 | 54 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
55 | } |
56 | } | |
57 | ||
1da177e4 LT |
58 | static void enqueue_huge_page(struct page *page) |
59 | { | |
60 | int nid = page_to_nid(page); | |
61 | list_add(&page->lru, &hugepage_freelists[nid]); | |
62 | free_huge_pages++; | |
63 | free_huge_pages_node[nid]++; | |
64 | } | |
65 | ||
5da7ca86 CL |
66 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
67 | unsigned long address) | |
1da177e4 LT |
68 | { |
69 | int nid = numa_node_id(); | |
70 | struct page *page = NULL; | |
5da7ca86 | 71 | struct zonelist *zonelist = huge_zonelist(vma, address); |
96df9333 | 72 | struct zone **z; |
1da177e4 | 73 | |
96df9333 | 74 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 75 | nid = zone_to_nid(*z); |
02a0e53d | 76 | if (cpuset_zone_allowed_softwall(*z, GFP_HIGHUSER) && |
aea47ff3 | 77 | !list_empty(&hugepage_freelists[nid])) |
96df9333 | 78 | break; |
1da177e4 | 79 | } |
96df9333 CL |
80 | |
81 | if (*z) { | |
1da177e4 LT |
82 | page = list_entry(hugepage_freelists[nid].next, |
83 | struct page, lru); | |
84 | list_del(&page->lru); | |
85 | free_huge_pages--; | |
86 | free_huge_pages_node[nid]--; | |
87 | } | |
88 | return page; | |
89 | } | |
90 | ||
27a85ef1 DG |
91 | static void free_huge_page(struct page *page) |
92 | { | |
93 | BUG_ON(page_count(page)); | |
94 | ||
95 | INIT_LIST_HEAD(&page->lru); | |
96 | ||
97 | spin_lock(&hugetlb_lock); | |
98 | enqueue_huge_page(page); | |
99 | spin_unlock(&hugetlb_lock); | |
100 | } | |
101 | ||
a482289d | 102 | static int alloc_fresh_huge_page(void) |
1da177e4 LT |
103 | { |
104 | static int nid = 0; | |
105 | struct page *page; | |
106 | page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, | |
107 | HUGETLB_PAGE_ORDER); | |
fdb7cc59 PJ |
108 | nid = next_node(nid, node_online_map); |
109 | if (nid == MAX_NUMNODES) | |
110 | nid = first_node(node_online_map); | |
1da177e4 | 111 | if (page) { |
33f2ef89 | 112 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 113 | spin_lock(&hugetlb_lock); |
1da177e4 LT |
114 | nr_huge_pages++; |
115 | nr_huge_pages_node[page_to_nid(page)]++; | |
0bd0f9fb | 116 | spin_unlock(&hugetlb_lock); |
a482289d NP |
117 | put_page(page); /* free it into the hugepage allocator */ |
118 | return 1; | |
1da177e4 | 119 | } |
a482289d | 120 | return 0; |
1da177e4 LT |
121 | } |
122 | ||
27a85ef1 DG |
123 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
124 | unsigned long addr) | |
1da177e4 LT |
125 | { |
126 | struct page *page; | |
1da177e4 LT |
127 | |
128 | spin_lock(&hugetlb_lock); | |
a43a8c39 KC |
129 | if (vma->vm_flags & VM_MAYSHARE) |
130 | resv_huge_pages--; | |
131 | else if (free_huge_pages <= resv_huge_pages) | |
132 | goto fail; | |
b45b5bd6 DG |
133 | |
134 | page = dequeue_huge_page(vma, addr); | |
135 | if (!page) | |
136 | goto fail; | |
137 | ||
1da177e4 | 138 | spin_unlock(&hugetlb_lock); |
7835e98b | 139 | set_page_refcounted(page); |
1da177e4 | 140 | return page; |
b45b5bd6 | 141 | |
a43a8c39 | 142 | fail: |
ace4bd29 KC |
143 | if (vma->vm_flags & VM_MAYSHARE) |
144 | resv_huge_pages++; | |
b45b5bd6 DG |
145 | spin_unlock(&hugetlb_lock); |
146 | return NULL; | |
147 | } | |
148 | ||
1da177e4 LT |
149 | static int __init hugetlb_init(void) |
150 | { | |
151 | unsigned long i; | |
1da177e4 | 152 | |
3c726f8d BH |
153 | if (HPAGE_SHIFT == 0) |
154 | return 0; | |
155 | ||
1da177e4 LT |
156 | for (i = 0; i < MAX_NUMNODES; ++i) |
157 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
158 | ||
159 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 160 | if (!alloc_fresh_huge_page()) |
1da177e4 | 161 | break; |
1da177e4 LT |
162 | } |
163 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
164 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
165 | return 0; | |
166 | } | |
167 | module_init(hugetlb_init); | |
168 | ||
169 | static int __init hugetlb_setup(char *s) | |
170 | { | |
171 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
172 | max_huge_pages = 0; | |
173 | return 1; | |
174 | } | |
175 | __setup("hugepages=", hugetlb_setup); | |
176 | ||
8a630112 KC |
177 | static unsigned int cpuset_mems_nr(unsigned int *array) |
178 | { | |
179 | int node; | |
180 | unsigned int nr = 0; | |
181 | ||
182 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
183 | nr += array[node]; | |
184 | ||
185 | return nr; | |
186 | } | |
187 | ||
1da177e4 LT |
188 | #ifdef CONFIG_SYSCTL |
189 | static void update_and_free_page(struct page *page) | |
190 | { | |
191 | int i; | |
192 | nr_huge_pages--; | |
4415cc8d | 193 | nr_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
194 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
195 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
196 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
197 | 1 << PG_private | 1<< PG_writeback); | |
1da177e4 | 198 | } |
a482289d | 199 | page[1].lru.next = NULL; |
7835e98b | 200 | set_page_refcounted(page); |
1da177e4 LT |
201 | __free_pages(page, HUGETLB_PAGE_ORDER); |
202 | } | |
203 | ||
204 | #ifdef CONFIG_HIGHMEM | |
205 | static void try_to_free_low(unsigned long count) | |
206 | { | |
4415cc8d CL |
207 | int i; |
208 | ||
1da177e4 LT |
209 | for (i = 0; i < MAX_NUMNODES; ++i) { |
210 | struct page *page, *next; | |
211 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
212 | if (PageHighMem(page)) | |
213 | continue; | |
214 | list_del(&page->lru); | |
215 | update_and_free_page(page); | |
1da177e4 | 216 | free_huge_pages--; |
4415cc8d | 217 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
218 | if (count >= nr_huge_pages) |
219 | return; | |
220 | } | |
221 | } | |
222 | } | |
223 | #else | |
224 | static inline void try_to_free_low(unsigned long count) | |
225 | { | |
226 | } | |
227 | #endif | |
228 | ||
229 | static unsigned long set_max_huge_pages(unsigned long count) | |
230 | { | |
231 | while (count > nr_huge_pages) { | |
a482289d | 232 | if (!alloc_fresh_huge_page()) |
1da177e4 | 233 | return nr_huge_pages; |
1da177e4 LT |
234 | } |
235 | if (count >= nr_huge_pages) | |
236 | return nr_huge_pages; | |
237 | ||
238 | spin_lock(&hugetlb_lock); | |
a43a8c39 | 239 | count = max(count, resv_huge_pages); |
1da177e4 LT |
240 | try_to_free_low(count); |
241 | while (count < nr_huge_pages) { | |
5da7ca86 | 242 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
243 | if (!page) |
244 | break; | |
245 | update_and_free_page(page); | |
246 | } | |
247 | spin_unlock(&hugetlb_lock); | |
248 | return nr_huge_pages; | |
249 | } | |
250 | ||
251 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
252 | struct file *file, void __user *buffer, | |
253 | size_t *length, loff_t *ppos) | |
254 | { | |
255 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
256 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
257 | return 0; | |
258 | } | |
259 | #endif /* CONFIG_SYSCTL */ | |
260 | ||
261 | int hugetlb_report_meminfo(char *buf) | |
262 | { | |
263 | return sprintf(buf, | |
264 | "HugePages_Total: %5lu\n" | |
265 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 266 | "HugePages_Rsvd: %5lu\n" |
1da177e4 LT |
267 | "Hugepagesize: %5lu kB\n", |
268 | nr_huge_pages, | |
269 | free_huge_pages, | |
a43a8c39 | 270 | resv_huge_pages, |
1da177e4 LT |
271 | HPAGE_SIZE/1024); |
272 | } | |
273 | ||
274 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
275 | { | |
276 | return sprintf(buf, | |
277 | "Node %d HugePages_Total: %5u\n" | |
278 | "Node %d HugePages_Free: %5u\n", | |
279 | nid, nr_huge_pages_node[nid], | |
280 | nid, free_huge_pages_node[nid]); | |
281 | } | |
282 | ||
1da177e4 LT |
283 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
284 | unsigned long hugetlb_total_pages(void) | |
285 | { | |
286 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
287 | } | |
1da177e4 LT |
288 | |
289 | /* | |
290 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
291 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
292 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
293 | * this far. | |
294 | */ | |
295 | static struct page *hugetlb_nopage(struct vm_area_struct *vma, | |
296 | unsigned long address, int *unused) | |
297 | { | |
298 | BUG(); | |
299 | return NULL; | |
300 | } | |
301 | ||
302 | struct vm_operations_struct hugetlb_vm_ops = { | |
303 | .nopage = hugetlb_nopage, | |
304 | }; | |
305 | ||
1e8f889b DG |
306 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
307 | int writable) | |
63551ae0 DG |
308 | { |
309 | pte_t entry; | |
310 | ||
1e8f889b | 311 | if (writable) { |
63551ae0 DG |
312 | entry = |
313 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
314 | } else { | |
315 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
316 | } | |
317 | entry = pte_mkyoung(entry); | |
318 | entry = pte_mkhuge(entry); | |
319 | ||
320 | return entry; | |
321 | } | |
322 | ||
1e8f889b DG |
323 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
324 | unsigned long address, pte_t *ptep) | |
325 | { | |
326 | pte_t entry; | |
327 | ||
328 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
329 | ptep_set_access_flags(vma, address, ptep, entry, 1); | |
330 | update_mmu_cache(vma, address, entry); | |
331 | lazy_mmu_prot_update(entry); | |
332 | } | |
333 | ||
334 | ||
63551ae0 DG |
335 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
336 | struct vm_area_struct *vma) | |
337 | { | |
338 | pte_t *src_pte, *dst_pte, entry; | |
339 | struct page *ptepage; | |
1c59827d | 340 | unsigned long addr; |
1e8f889b DG |
341 | int cow; |
342 | ||
343 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 344 | |
1c59827d | 345 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
346 | src_pte = huge_pte_offset(src, addr); |
347 | if (!src_pte) | |
348 | continue; | |
63551ae0 DG |
349 | dst_pte = huge_pte_alloc(dst, addr); |
350 | if (!dst_pte) | |
351 | goto nomem; | |
c74df32c | 352 | spin_lock(&dst->page_table_lock); |
1c59827d | 353 | spin_lock(&src->page_table_lock); |
c74df32c | 354 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
355 | if (cow) |
356 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
357 | entry = *src_pte; |
358 | ptepage = pte_page(entry); | |
359 | get_page(ptepage); | |
1c59827d HD |
360 | set_huge_pte_at(dst, addr, dst_pte, entry); |
361 | } | |
362 | spin_unlock(&src->page_table_lock); | |
c74df32c | 363 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
364 | } |
365 | return 0; | |
366 | ||
367 | nomem: | |
368 | return -ENOMEM; | |
369 | } | |
370 | ||
502717f4 KC |
371 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
372 | unsigned long end) | |
63551ae0 DG |
373 | { |
374 | struct mm_struct *mm = vma->vm_mm; | |
375 | unsigned long address; | |
c7546f8f | 376 | pte_t *ptep; |
63551ae0 DG |
377 | pte_t pte; |
378 | struct page *page; | |
fe1668ae | 379 | struct page *tmp; |
c0a499c2 KC |
380 | /* |
381 | * A page gathering list, protected by per file i_mmap_lock. The | |
382 | * lock is used to avoid list corruption from multiple unmapping | |
383 | * of the same page since we are using page->lru. | |
384 | */ | |
fe1668ae | 385 | LIST_HEAD(page_list); |
63551ae0 DG |
386 | |
387 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
388 | BUG_ON(start & ~HPAGE_MASK); | |
389 | BUG_ON(end & ~HPAGE_MASK); | |
390 | ||
508034a3 | 391 | spin_lock(&mm->page_table_lock); |
63551ae0 | 392 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 393 | ptep = huge_pte_offset(mm, address); |
4c887265 | 394 | if (!ptep) |
c7546f8f DG |
395 | continue; |
396 | ||
39dde65c KC |
397 | if (huge_pmd_unshare(mm, &address, ptep)) |
398 | continue; | |
399 | ||
c7546f8f | 400 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
401 | if (pte_none(pte)) |
402 | continue; | |
c7546f8f | 403 | |
63551ae0 | 404 | page = pte_page(pte); |
6649a386 KC |
405 | if (pte_dirty(pte)) |
406 | set_page_dirty(page); | |
fe1668ae | 407 | list_add(&page->lru, &page_list); |
63551ae0 | 408 | } |
1da177e4 | 409 | spin_unlock(&mm->page_table_lock); |
508034a3 | 410 | flush_tlb_range(vma, start, end); |
fe1668ae KC |
411 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
412 | list_del(&page->lru); | |
413 | put_page(page); | |
414 | } | |
1da177e4 | 415 | } |
63551ae0 | 416 | |
502717f4 KC |
417 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
418 | unsigned long end) | |
419 | { | |
420 | /* | |
421 | * It is undesirable to test vma->vm_file as it should be non-null | |
422 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
423 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
424 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
425 | * to clean up. Since no pte has actually been setup, it is safe to | |
426 | * do nothing in this case. | |
427 | */ | |
428 | if (vma->vm_file) { | |
429 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
430 | __unmap_hugepage_range(vma, start, end); | |
431 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
432 | } | |
433 | } | |
434 | ||
1e8f889b DG |
435 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
436 | unsigned long address, pte_t *ptep, pte_t pte) | |
437 | { | |
438 | struct page *old_page, *new_page; | |
79ac6ba4 | 439 | int avoidcopy; |
1e8f889b DG |
440 | |
441 | old_page = pte_page(pte); | |
442 | ||
443 | /* If no-one else is actually using this page, avoid the copy | |
444 | * and just make the page writable */ | |
445 | avoidcopy = (page_count(old_page) == 1); | |
446 | if (avoidcopy) { | |
447 | set_huge_ptep_writable(vma, address, ptep); | |
448 | return VM_FAULT_MINOR; | |
449 | } | |
450 | ||
451 | page_cache_get(old_page); | |
5da7ca86 | 452 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
453 | |
454 | if (!new_page) { | |
455 | page_cache_release(old_page); | |
0df420d8 | 456 | return VM_FAULT_OOM; |
1e8f889b DG |
457 | } |
458 | ||
459 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 460 | copy_huge_page(new_page, old_page, address, vma); |
1e8f889b DG |
461 | spin_lock(&mm->page_table_lock); |
462 | ||
463 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
464 | if (likely(pte_same(*ptep, pte))) { | |
465 | /* Break COW */ | |
466 | set_huge_pte_at(mm, address, ptep, | |
467 | make_huge_pte(vma, new_page, 1)); | |
468 | /* Make the old page be freed below */ | |
469 | new_page = old_page; | |
470 | } | |
471 | page_cache_release(new_page); | |
472 | page_cache_release(old_page); | |
473 | return VM_FAULT_MINOR; | |
474 | } | |
475 | ||
86e5216f | 476 | int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 477 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
478 | { |
479 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
480 | unsigned long idx; |
481 | unsigned long size; | |
4c887265 AL |
482 | struct page *page; |
483 | struct address_space *mapping; | |
1e8f889b | 484 | pte_t new_pte; |
4c887265 | 485 | |
4c887265 AL |
486 | mapping = vma->vm_file->f_mapping; |
487 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
488 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
489 | ||
490 | /* | |
491 | * Use page lock to guard against racing truncation | |
492 | * before we get page_table_lock. | |
493 | */ | |
6bda666a CL |
494 | retry: |
495 | page = find_lock_page(mapping, idx); | |
496 | if (!page) { | |
ebed4bfc HD |
497 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
498 | if (idx >= size) | |
499 | goto out; | |
6bda666a CL |
500 | if (hugetlb_get_quota(mapping)) |
501 | goto out; | |
502 | page = alloc_huge_page(vma, address); | |
503 | if (!page) { | |
504 | hugetlb_put_quota(mapping); | |
0df420d8 | 505 | ret = VM_FAULT_OOM; |
6bda666a CL |
506 | goto out; |
507 | } | |
79ac6ba4 | 508 | clear_huge_page(page, address); |
ac9b9c66 | 509 | |
6bda666a CL |
510 | if (vma->vm_flags & VM_SHARED) { |
511 | int err; | |
512 | ||
513 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
514 | if (err) { | |
515 | put_page(page); | |
516 | hugetlb_put_quota(mapping); | |
517 | if (err == -EEXIST) | |
518 | goto retry; | |
519 | goto out; | |
520 | } | |
521 | } else | |
522 | lock_page(page); | |
523 | } | |
1e8f889b | 524 | |
ac9b9c66 | 525 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
526 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
527 | if (idx >= size) | |
528 | goto backout; | |
529 | ||
530 | ret = VM_FAULT_MINOR; | |
86e5216f | 531 | if (!pte_none(*ptep)) |
4c887265 AL |
532 | goto backout; |
533 | ||
1e8f889b DG |
534 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
535 | && (vma->vm_flags & VM_SHARED))); | |
536 | set_huge_pte_at(mm, address, ptep, new_pte); | |
537 | ||
538 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
539 | /* Optimization, do the COW without a second fault */ | |
540 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
541 | } | |
542 | ||
ac9b9c66 | 543 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
544 | unlock_page(page); |
545 | out: | |
ac9b9c66 | 546 | return ret; |
4c887265 AL |
547 | |
548 | backout: | |
549 | spin_unlock(&mm->page_table_lock); | |
550 | hugetlb_put_quota(mapping); | |
551 | unlock_page(page); | |
552 | put_page(page); | |
553 | goto out; | |
ac9b9c66 HD |
554 | } |
555 | ||
86e5216f AL |
556 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
557 | unsigned long address, int write_access) | |
558 | { | |
559 | pte_t *ptep; | |
560 | pte_t entry; | |
1e8f889b | 561 | int ret; |
3935baa9 | 562 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
563 | |
564 | ptep = huge_pte_alloc(mm, address); | |
565 | if (!ptep) | |
566 | return VM_FAULT_OOM; | |
567 | ||
3935baa9 DG |
568 | /* |
569 | * Serialize hugepage allocation and instantiation, so that we don't | |
570 | * get spurious allocation failures if two CPUs race to instantiate | |
571 | * the same page in the page cache. | |
572 | */ | |
573 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 574 | entry = *ptep; |
3935baa9 DG |
575 | if (pte_none(entry)) { |
576 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
577 | mutex_unlock(&hugetlb_instantiation_mutex); | |
578 | return ret; | |
579 | } | |
86e5216f | 580 | |
1e8f889b DG |
581 | ret = VM_FAULT_MINOR; |
582 | ||
583 | spin_lock(&mm->page_table_lock); | |
584 | /* Check for a racing update before calling hugetlb_cow */ | |
585 | if (likely(pte_same(entry, *ptep))) | |
586 | if (write_access && !pte_write(entry)) | |
587 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
588 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 589 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
590 | |
591 | return ret; | |
86e5216f AL |
592 | } |
593 | ||
63551ae0 DG |
594 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
595 | struct page **pages, struct vm_area_struct **vmas, | |
596 | unsigned long *position, int *length, int i) | |
597 | { | |
d5d4b0aa KC |
598 | unsigned long pfn_offset; |
599 | unsigned long vaddr = *position; | |
63551ae0 DG |
600 | int remainder = *length; |
601 | ||
1c59827d | 602 | spin_lock(&mm->page_table_lock); |
63551ae0 | 603 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
604 | pte_t *pte; |
605 | struct page *page; | |
63551ae0 | 606 | |
4c887265 AL |
607 | /* |
608 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
609 | * each hugepage. We have to make * sure we get the | |
610 | * first, for the page indexing below to work. | |
611 | */ | |
612 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 613 | |
4c887265 AL |
614 | if (!pte || pte_none(*pte)) { |
615 | int ret; | |
63551ae0 | 616 | |
4c887265 AL |
617 | spin_unlock(&mm->page_table_lock); |
618 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
619 | spin_lock(&mm->page_table_lock); | |
620 | if (ret == VM_FAULT_MINOR) | |
621 | continue; | |
63551ae0 | 622 | |
4c887265 AL |
623 | remainder = 0; |
624 | if (!i) | |
625 | i = -EFAULT; | |
626 | break; | |
627 | } | |
628 | ||
d5d4b0aa KC |
629 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
630 | page = pte_page(*pte); | |
631 | same_page: | |
d6692183 KC |
632 | if (pages) { |
633 | get_page(page); | |
d5d4b0aa | 634 | pages[i] = page + pfn_offset; |
d6692183 | 635 | } |
63551ae0 DG |
636 | |
637 | if (vmas) | |
638 | vmas[i] = vma; | |
639 | ||
640 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 641 | ++pfn_offset; |
63551ae0 DG |
642 | --remainder; |
643 | ++i; | |
d5d4b0aa KC |
644 | if (vaddr < vma->vm_end && remainder && |
645 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
646 | /* | |
647 | * We use pfn_offset to avoid touching the pageframes | |
648 | * of this compound page. | |
649 | */ | |
650 | goto same_page; | |
651 | } | |
63551ae0 | 652 | } |
1c59827d | 653 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
654 | *length = remainder; |
655 | *position = vaddr; | |
656 | ||
657 | return i; | |
658 | } | |
8f860591 ZY |
659 | |
660 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
661 | unsigned long address, unsigned long end, pgprot_t newprot) | |
662 | { | |
663 | struct mm_struct *mm = vma->vm_mm; | |
664 | unsigned long start = address; | |
665 | pte_t *ptep; | |
666 | pte_t pte; | |
667 | ||
668 | BUG_ON(address >= end); | |
669 | flush_cache_range(vma, address, end); | |
670 | ||
39dde65c | 671 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
672 | spin_lock(&mm->page_table_lock); |
673 | for (; address < end; address += HPAGE_SIZE) { | |
674 | ptep = huge_pte_offset(mm, address); | |
675 | if (!ptep) | |
676 | continue; | |
39dde65c KC |
677 | if (huge_pmd_unshare(mm, &address, ptep)) |
678 | continue; | |
8f860591 ZY |
679 | if (!pte_none(*ptep)) { |
680 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
681 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
682 | set_huge_pte_at(mm, address, ptep, pte); | |
683 | lazy_mmu_prot_update(pte); | |
684 | } | |
685 | } | |
686 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 687 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
688 | |
689 | flush_tlb_range(vma, start, end); | |
690 | } | |
691 | ||
a43a8c39 KC |
692 | struct file_region { |
693 | struct list_head link; | |
694 | long from; | |
695 | long to; | |
696 | }; | |
697 | ||
698 | static long region_add(struct list_head *head, long f, long t) | |
699 | { | |
700 | struct file_region *rg, *nrg, *trg; | |
701 | ||
702 | /* Locate the region we are either in or before. */ | |
703 | list_for_each_entry(rg, head, link) | |
704 | if (f <= rg->to) | |
705 | break; | |
706 | ||
707 | /* Round our left edge to the current segment if it encloses us. */ | |
708 | if (f > rg->from) | |
709 | f = rg->from; | |
710 | ||
711 | /* Check for and consume any regions we now overlap with. */ | |
712 | nrg = rg; | |
713 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
714 | if (&rg->link == head) | |
715 | break; | |
716 | if (rg->from > t) | |
717 | break; | |
718 | ||
719 | /* If this area reaches higher then extend our area to | |
720 | * include it completely. If this is not the first area | |
721 | * which we intend to reuse, free it. */ | |
722 | if (rg->to > t) | |
723 | t = rg->to; | |
724 | if (rg != nrg) { | |
725 | list_del(&rg->link); | |
726 | kfree(rg); | |
727 | } | |
728 | } | |
729 | nrg->from = f; | |
730 | nrg->to = t; | |
731 | return 0; | |
732 | } | |
733 | ||
734 | static long region_chg(struct list_head *head, long f, long t) | |
735 | { | |
736 | struct file_region *rg, *nrg; | |
737 | long chg = 0; | |
738 | ||
739 | /* Locate the region we are before or in. */ | |
740 | list_for_each_entry(rg, head, link) | |
741 | if (f <= rg->to) | |
742 | break; | |
743 | ||
744 | /* If we are below the current region then a new region is required. | |
745 | * Subtle, allocate a new region at the position but make it zero | |
746 | * size such that we can guarentee to record the reservation. */ | |
747 | if (&rg->link == head || t < rg->from) { | |
748 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
749 | if (nrg == 0) | |
750 | return -ENOMEM; | |
751 | nrg->from = f; | |
752 | nrg->to = f; | |
753 | INIT_LIST_HEAD(&nrg->link); | |
754 | list_add(&nrg->link, rg->link.prev); | |
755 | ||
756 | return t - f; | |
757 | } | |
758 | ||
759 | /* Round our left edge to the current segment if it encloses us. */ | |
760 | if (f > rg->from) | |
761 | f = rg->from; | |
762 | chg = t - f; | |
763 | ||
764 | /* Check for and consume any regions we now overlap with. */ | |
765 | list_for_each_entry(rg, rg->link.prev, link) { | |
766 | if (&rg->link == head) | |
767 | break; | |
768 | if (rg->from > t) | |
769 | return chg; | |
770 | ||
771 | /* We overlap with this area, if it extends futher than | |
772 | * us then we must extend ourselves. Account for its | |
773 | * existing reservation. */ | |
774 | if (rg->to > t) { | |
775 | chg += rg->to - t; | |
776 | t = rg->to; | |
777 | } | |
778 | chg -= rg->to - rg->from; | |
779 | } | |
780 | return chg; | |
781 | } | |
782 | ||
783 | static long region_truncate(struct list_head *head, long end) | |
784 | { | |
785 | struct file_region *rg, *trg; | |
786 | long chg = 0; | |
787 | ||
788 | /* Locate the region we are either in or before. */ | |
789 | list_for_each_entry(rg, head, link) | |
790 | if (end <= rg->to) | |
791 | break; | |
792 | if (&rg->link == head) | |
793 | return 0; | |
794 | ||
795 | /* If we are in the middle of a region then adjust it. */ | |
796 | if (end > rg->from) { | |
797 | chg = rg->to - end; | |
798 | rg->to = end; | |
799 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
800 | } | |
801 | ||
802 | /* Drop any remaining regions. */ | |
803 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
804 | if (&rg->link == head) | |
805 | break; | |
806 | chg += rg->to - rg->from; | |
807 | list_del(&rg->link); | |
808 | kfree(rg); | |
809 | } | |
810 | return chg; | |
811 | } | |
812 | ||
813 | static int hugetlb_acct_memory(long delta) | |
814 | { | |
815 | int ret = -ENOMEM; | |
816 | ||
817 | spin_lock(&hugetlb_lock); | |
818 | if ((delta + resv_huge_pages) <= free_huge_pages) { | |
819 | resv_huge_pages += delta; | |
820 | ret = 0; | |
821 | } | |
822 | spin_unlock(&hugetlb_lock); | |
823 | return ret; | |
824 | } | |
825 | ||
826 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
827 | { | |
828 | long ret, chg; | |
829 | ||
830 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
831 | if (chg < 0) | |
832 | return chg; | |
8a630112 KC |
833 | /* |
834 | * When cpuset is configured, it breaks the strict hugetlb page | |
835 | * reservation as the accounting is done on a global variable. Such | |
836 | * reservation is completely rubbish in the presence of cpuset because | |
837 | * the reservation is not checked against page availability for the | |
838 | * current cpuset. Application can still potentially OOM'ed by kernel | |
839 | * with lack of free htlb page in cpuset that the task is in. | |
840 | * Attempt to enforce strict accounting with cpuset is almost | |
841 | * impossible (or too ugly) because cpuset is too fluid that | |
842 | * task or memory node can be dynamically moved between cpusets. | |
843 | * | |
844 | * The change of semantics for shared hugetlb mapping with cpuset is | |
845 | * undesirable. However, in order to preserve some of the semantics, | |
846 | * we fall back to check against current free page availability as | |
847 | * a best attempt and hopefully to minimize the impact of changing | |
848 | * semantics that cpuset has. | |
849 | */ | |
850 | if (chg > cpuset_mems_nr(free_huge_pages_node)) | |
851 | return -ENOMEM; | |
852 | ||
a43a8c39 KC |
853 | ret = hugetlb_acct_memory(chg); |
854 | if (ret < 0) | |
855 | return ret; | |
856 | region_add(&inode->i_mapping->private_list, from, to); | |
857 | return 0; | |
858 | } | |
859 | ||
860 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
861 | { | |
862 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
863 | hugetlb_acct_memory(freed - chg); | |
864 | } |