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Commit | Line | Data |
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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]; | |
396faf03 MG |
30 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
31 | unsigned long hugepages_treat_as_movable; | |
32 | ||
3935baa9 DG |
33 | /* |
34 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
35 | */ | |
36 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 37 | |
79ac6ba4 DG |
38 | static void clear_huge_page(struct page *page, unsigned long addr) |
39 | { | |
40 | int i; | |
41 | ||
42 | might_sleep(); | |
43 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
44 | cond_resched(); | |
45 | clear_user_highpage(page + i, addr); | |
46 | } | |
47 | } | |
48 | ||
49 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 50 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
51 | { |
52 | int i; | |
53 | ||
54 | might_sleep(); | |
55 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
56 | cond_resched(); | |
9de455b2 | 57 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
58 | } |
59 | } | |
60 | ||
1da177e4 LT |
61 | static void enqueue_huge_page(struct page *page) |
62 | { | |
63 | int nid = page_to_nid(page); | |
64 | list_add(&page->lru, &hugepage_freelists[nid]); | |
65 | free_huge_pages++; | |
66 | free_huge_pages_node[nid]++; | |
67 | } | |
68 | ||
5da7ca86 CL |
69 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
70 | unsigned long address) | |
1da177e4 | 71 | { |
31a5c6e4 | 72 | int nid; |
1da177e4 | 73 | struct page *page = NULL; |
396faf03 MG |
74 | struct zonelist *zonelist = huge_zonelist(vma, address, |
75 | htlb_alloc_mask); | |
96df9333 | 76 | struct zone **z; |
1da177e4 | 77 | |
96df9333 | 78 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 79 | nid = zone_to_nid(*z); |
396faf03 | 80 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
3abf7afd AM |
81 | !list_empty(&hugepage_freelists[nid])) { |
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 | } | |
1da177e4 LT |
88 | } |
89 | return page; | |
90 | } | |
91 | ||
27a85ef1 DG |
92 | static void free_huge_page(struct page *page) |
93 | { | |
94 | BUG_ON(page_count(page)); | |
95 | ||
96 | INIT_LIST_HEAD(&page->lru); | |
97 | ||
98 | spin_lock(&hugetlb_lock); | |
99 | enqueue_huge_page(page); | |
100 | spin_unlock(&hugetlb_lock); | |
101 | } | |
102 | ||
a482289d | 103 | static int alloc_fresh_huge_page(void) |
1da177e4 | 104 | { |
f96efd58 | 105 | static int prev_nid; |
1da177e4 | 106 | struct page *page; |
f96efd58 JJ |
107 | int nid; |
108 | ||
7ed5cb2b HD |
109 | /* |
110 | * Copy static prev_nid to local nid, work on that, then copy it | |
111 | * back to prev_nid afterwards: otherwise there's a window in which | |
112 | * a racer might pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
113 | * But we don't need to use a spin_lock here: it really doesn't | |
114 | * matter if occasionally a racer chooses the same nid as we do. | |
115 | */ | |
f96efd58 | 116 | nid = next_node(prev_nid, node_online_map); |
fdb7cc59 PJ |
117 | if (nid == MAX_NUMNODES) |
118 | nid = first_node(node_online_map); | |
f96efd58 | 119 | prev_nid = nid; |
f96efd58 | 120 | |
396faf03 | 121 | page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
f96efd58 | 122 | HUGETLB_PAGE_ORDER); |
1da177e4 | 123 | if (page) { |
33f2ef89 | 124 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 125 | spin_lock(&hugetlb_lock); |
1da177e4 LT |
126 | nr_huge_pages++; |
127 | nr_huge_pages_node[page_to_nid(page)]++; | |
0bd0f9fb | 128 | spin_unlock(&hugetlb_lock); |
a482289d NP |
129 | put_page(page); /* free it into the hugepage allocator */ |
130 | return 1; | |
1da177e4 | 131 | } |
a482289d | 132 | return 0; |
1da177e4 LT |
133 | } |
134 | ||
27a85ef1 DG |
135 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
136 | unsigned long addr) | |
1da177e4 LT |
137 | { |
138 | struct page *page; | |
1da177e4 LT |
139 | |
140 | spin_lock(&hugetlb_lock); | |
a43a8c39 KC |
141 | if (vma->vm_flags & VM_MAYSHARE) |
142 | resv_huge_pages--; | |
143 | else if (free_huge_pages <= resv_huge_pages) | |
144 | goto fail; | |
b45b5bd6 DG |
145 | |
146 | page = dequeue_huge_page(vma, addr); | |
147 | if (!page) | |
148 | goto fail; | |
149 | ||
1da177e4 | 150 | spin_unlock(&hugetlb_lock); |
7835e98b | 151 | set_page_refcounted(page); |
1da177e4 | 152 | return page; |
b45b5bd6 | 153 | |
a43a8c39 | 154 | fail: |
ace4bd29 KC |
155 | if (vma->vm_flags & VM_MAYSHARE) |
156 | resv_huge_pages++; | |
b45b5bd6 DG |
157 | spin_unlock(&hugetlb_lock); |
158 | return NULL; | |
159 | } | |
160 | ||
1da177e4 LT |
161 | static int __init hugetlb_init(void) |
162 | { | |
163 | unsigned long i; | |
1da177e4 | 164 | |
3c726f8d BH |
165 | if (HPAGE_SHIFT == 0) |
166 | return 0; | |
167 | ||
1da177e4 LT |
168 | for (i = 0; i < MAX_NUMNODES; ++i) |
169 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
170 | ||
171 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 172 | if (!alloc_fresh_huge_page()) |
1da177e4 | 173 | break; |
1da177e4 LT |
174 | } |
175 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
176 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
177 | return 0; | |
178 | } | |
179 | module_init(hugetlb_init); | |
180 | ||
181 | static int __init hugetlb_setup(char *s) | |
182 | { | |
183 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
184 | max_huge_pages = 0; | |
185 | return 1; | |
186 | } | |
187 | __setup("hugepages=", hugetlb_setup); | |
188 | ||
8a630112 KC |
189 | static unsigned int cpuset_mems_nr(unsigned int *array) |
190 | { | |
191 | int node; | |
192 | unsigned int nr = 0; | |
193 | ||
194 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
195 | nr += array[node]; | |
196 | ||
197 | return nr; | |
198 | } | |
199 | ||
1da177e4 LT |
200 | #ifdef CONFIG_SYSCTL |
201 | static void update_and_free_page(struct page *page) | |
202 | { | |
203 | int i; | |
204 | nr_huge_pages--; | |
4415cc8d | 205 | nr_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
206 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
207 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
208 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
209 | 1 << PG_private | 1<< PG_writeback); | |
1da177e4 | 210 | } |
f8af0bb8 | 211 | set_compound_page_dtor(page, NULL); |
7835e98b | 212 | set_page_refcounted(page); |
1da177e4 LT |
213 | __free_pages(page, HUGETLB_PAGE_ORDER); |
214 | } | |
215 | ||
216 | #ifdef CONFIG_HIGHMEM | |
217 | static void try_to_free_low(unsigned long count) | |
218 | { | |
4415cc8d CL |
219 | int i; |
220 | ||
1da177e4 LT |
221 | for (i = 0; i < MAX_NUMNODES; ++i) { |
222 | struct page *page, *next; | |
223 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
224 | if (PageHighMem(page)) | |
225 | continue; | |
226 | list_del(&page->lru); | |
227 | update_and_free_page(page); | |
1da177e4 | 228 | free_huge_pages--; |
4415cc8d | 229 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
230 | if (count >= nr_huge_pages) |
231 | return; | |
232 | } | |
233 | } | |
234 | } | |
235 | #else | |
236 | static inline void try_to_free_low(unsigned long count) | |
237 | { | |
238 | } | |
239 | #endif | |
240 | ||
241 | static unsigned long set_max_huge_pages(unsigned long count) | |
242 | { | |
243 | while (count > nr_huge_pages) { | |
a482289d | 244 | if (!alloc_fresh_huge_page()) |
1da177e4 | 245 | return nr_huge_pages; |
1da177e4 LT |
246 | } |
247 | if (count >= nr_huge_pages) | |
248 | return nr_huge_pages; | |
249 | ||
250 | spin_lock(&hugetlb_lock); | |
a43a8c39 | 251 | count = max(count, resv_huge_pages); |
1da177e4 LT |
252 | try_to_free_low(count); |
253 | while (count < nr_huge_pages) { | |
5da7ca86 | 254 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
255 | if (!page) |
256 | break; | |
257 | update_and_free_page(page); | |
258 | } | |
259 | spin_unlock(&hugetlb_lock); | |
260 | return nr_huge_pages; | |
261 | } | |
262 | ||
263 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
264 | struct file *file, void __user *buffer, | |
265 | size_t *length, loff_t *ppos) | |
266 | { | |
267 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
268 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
269 | return 0; | |
270 | } | |
396faf03 MG |
271 | |
272 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
273 | struct file *file, void __user *buffer, | |
274 | size_t *length, loff_t *ppos) | |
275 | { | |
276 | proc_dointvec(table, write, file, buffer, length, ppos); | |
277 | if (hugepages_treat_as_movable) | |
278 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
279 | else | |
280 | htlb_alloc_mask = GFP_HIGHUSER; | |
281 | return 0; | |
282 | } | |
283 | ||
1da177e4 LT |
284 | #endif /* CONFIG_SYSCTL */ |
285 | ||
286 | int hugetlb_report_meminfo(char *buf) | |
287 | { | |
288 | return sprintf(buf, | |
289 | "HugePages_Total: %5lu\n" | |
290 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 291 | "HugePages_Rsvd: %5lu\n" |
1da177e4 LT |
292 | "Hugepagesize: %5lu kB\n", |
293 | nr_huge_pages, | |
294 | free_huge_pages, | |
a43a8c39 | 295 | resv_huge_pages, |
1da177e4 LT |
296 | HPAGE_SIZE/1024); |
297 | } | |
298 | ||
299 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
300 | { | |
301 | return sprintf(buf, | |
302 | "Node %d HugePages_Total: %5u\n" | |
303 | "Node %d HugePages_Free: %5u\n", | |
304 | nid, nr_huge_pages_node[nid], | |
305 | nid, free_huge_pages_node[nid]); | |
306 | } | |
307 | ||
1da177e4 LT |
308 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
309 | unsigned long hugetlb_total_pages(void) | |
310 | { | |
311 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
312 | } | |
1da177e4 LT |
313 | |
314 | /* | |
315 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
316 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
317 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
318 | * this far. | |
319 | */ | |
d0217ac0 | 320 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
321 | { |
322 | BUG(); | |
d0217ac0 | 323 | return 0; |
1da177e4 LT |
324 | } |
325 | ||
326 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 327 | .fault = hugetlb_vm_op_fault, |
1da177e4 LT |
328 | }; |
329 | ||
1e8f889b DG |
330 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
331 | int writable) | |
63551ae0 DG |
332 | { |
333 | pte_t entry; | |
334 | ||
1e8f889b | 335 | if (writable) { |
63551ae0 DG |
336 | entry = |
337 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
338 | } else { | |
339 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
340 | } | |
341 | entry = pte_mkyoung(entry); | |
342 | entry = pte_mkhuge(entry); | |
343 | ||
344 | return entry; | |
345 | } | |
346 | ||
1e8f889b DG |
347 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
348 | unsigned long address, pte_t *ptep) | |
349 | { | |
350 | pte_t entry; | |
351 | ||
352 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
8dab5241 BH |
353 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
354 | update_mmu_cache(vma, address, entry); | |
355 | lazy_mmu_prot_update(entry); | |
356 | } | |
1e8f889b DG |
357 | } |
358 | ||
359 | ||
63551ae0 DG |
360 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
361 | struct vm_area_struct *vma) | |
362 | { | |
363 | pte_t *src_pte, *dst_pte, entry; | |
364 | struct page *ptepage; | |
1c59827d | 365 | unsigned long addr; |
1e8f889b DG |
366 | int cow; |
367 | ||
368 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 369 | |
1c59827d | 370 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
371 | src_pte = huge_pte_offset(src, addr); |
372 | if (!src_pte) | |
373 | continue; | |
63551ae0 DG |
374 | dst_pte = huge_pte_alloc(dst, addr); |
375 | if (!dst_pte) | |
376 | goto nomem; | |
c74df32c | 377 | spin_lock(&dst->page_table_lock); |
1c59827d | 378 | spin_lock(&src->page_table_lock); |
c74df32c | 379 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
380 | if (cow) |
381 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
382 | entry = *src_pte; |
383 | ptepage = pte_page(entry); | |
384 | get_page(ptepage); | |
1c59827d HD |
385 | set_huge_pte_at(dst, addr, dst_pte, entry); |
386 | } | |
387 | spin_unlock(&src->page_table_lock); | |
c74df32c | 388 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
389 | } |
390 | return 0; | |
391 | ||
392 | nomem: | |
393 | return -ENOMEM; | |
394 | } | |
395 | ||
502717f4 KC |
396 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
397 | unsigned long end) | |
63551ae0 DG |
398 | { |
399 | struct mm_struct *mm = vma->vm_mm; | |
400 | unsigned long address; | |
c7546f8f | 401 | pte_t *ptep; |
63551ae0 DG |
402 | pte_t pte; |
403 | struct page *page; | |
fe1668ae | 404 | struct page *tmp; |
c0a499c2 KC |
405 | /* |
406 | * A page gathering list, protected by per file i_mmap_lock. The | |
407 | * lock is used to avoid list corruption from multiple unmapping | |
408 | * of the same page since we are using page->lru. | |
409 | */ | |
fe1668ae | 410 | LIST_HEAD(page_list); |
63551ae0 DG |
411 | |
412 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
413 | BUG_ON(start & ~HPAGE_MASK); | |
414 | BUG_ON(end & ~HPAGE_MASK); | |
415 | ||
508034a3 | 416 | spin_lock(&mm->page_table_lock); |
63551ae0 | 417 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 418 | ptep = huge_pte_offset(mm, address); |
4c887265 | 419 | if (!ptep) |
c7546f8f DG |
420 | continue; |
421 | ||
39dde65c KC |
422 | if (huge_pmd_unshare(mm, &address, ptep)) |
423 | continue; | |
424 | ||
c7546f8f | 425 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
426 | if (pte_none(pte)) |
427 | continue; | |
c7546f8f | 428 | |
63551ae0 | 429 | page = pte_page(pte); |
6649a386 KC |
430 | if (pte_dirty(pte)) |
431 | set_page_dirty(page); | |
fe1668ae | 432 | list_add(&page->lru, &page_list); |
63551ae0 | 433 | } |
1da177e4 | 434 | spin_unlock(&mm->page_table_lock); |
508034a3 | 435 | flush_tlb_range(vma, start, end); |
fe1668ae KC |
436 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
437 | list_del(&page->lru); | |
438 | put_page(page); | |
439 | } | |
1da177e4 | 440 | } |
63551ae0 | 441 | |
502717f4 KC |
442 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
443 | unsigned long end) | |
444 | { | |
445 | /* | |
446 | * It is undesirable to test vma->vm_file as it should be non-null | |
447 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
448 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
449 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
450 | * to clean up. Since no pte has actually been setup, it is safe to | |
451 | * do nothing in this case. | |
452 | */ | |
453 | if (vma->vm_file) { | |
454 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
455 | __unmap_hugepage_range(vma, start, end); | |
456 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
457 | } | |
458 | } | |
459 | ||
1e8f889b DG |
460 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
461 | unsigned long address, pte_t *ptep, pte_t pte) | |
462 | { | |
463 | struct page *old_page, *new_page; | |
79ac6ba4 | 464 | int avoidcopy; |
1e8f889b DG |
465 | |
466 | old_page = pte_page(pte); | |
467 | ||
468 | /* If no-one else is actually using this page, avoid the copy | |
469 | * and just make the page writable */ | |
470 | avoidcopy = (page_count(old_page) == 1); | |
471 | if (avoidcopy) { | |
472 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 473 | return 0; |
1e8f889b DG |
474 | } |
475 | ||
476 | page_cache_get(old_page); | |
5da7ca86 | 477 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
478 | |
479 | if (!new_page) { | |
480 | page_cache_release(old_page); | |
0df420d8 | 481 | return VM_FAULT_OOM; |
1e8f889b DG |
482 | } |
483 | ||
484 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 485 | copy_huge_page(new_page, old_page, address, vma); |
1e8f889b DG |
486 | spin_lock(&mm->page_table_lock); |
487 | ||
488 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
489 | if (likely(pte_same(*ptep, pte))) { | |
490 | /* Break COW */ | |
491 | set_huge_pte_at(mm, address, ptep, | |
492 | make_huge_pte(vma, new_page, 1)); | |
493 | /* Make the old page be freed below */ | |
494 | new_page = old_page; | |
495 | } | |
496 | page_cache_release(new_page); | |
497 | page_cache_release(old_page); | |
83c54070 | 498 | return 0; |
1e8f889b DG |
499 | } |
500 | ||
a1ed3dda | 501 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 502 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
503 | { |
504 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
505 | unsigned long idx; |
506 | unsigned long size; | |
4c887265 AL |
507 | struct page *page; |
508 | struct address_space *mapping; | |
1e8f889b | 509 | pte_t new_pte; |
4c887265 | 510 | |
4c887265 AL |
511 | mapping = vma->vm_file->f_mapping; |
512 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
513 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
514 | ||
515 | /* | |
516 | * Use page lock to guard against racing truncation | |
517 | * before we get page_table_lock. | |
518 | */ | |
6bda666a CL |
519 | retry: |
520 | page = find_lock_page(mapping, idx); | |
521 | if (!page) { | |
ebed4bfc HD |
522 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
523 | if (idx >= size) | |
524 | goto out; | |
6bda666a CL |
525 | if (hugetlb_get_quota(mapping)) |
526 | goto out; | |
527 | page = alloc_huge_page(vma, address); | |
528 | if (!page) { | |
529 | hugetlb_put_quota(mapping); | |
0df420d8 | 530 | ret = VM_FAULT_OOM; |
6bda666a CL |
531 | goto out; |
532 | } | |
79ac6ba4 | 533 | clear_huge_page(page, address); |
ac9b9c66 | 534 | |
6bda666a CL |
535 | if (vma->vm_flags & VM_SHARED) { |
536 | int err; | |
537 | ||
538 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
539 | if (err) { | |
540 | put_page(page); | |
541 | hugetlb_put_quota(mapping); | |
542 | if (err == -EEXIST) | |
543 | goto retry; | |
544 | goto out; | |
545 | } | |
546 | } else | |
547 | lock_page(page); | |
548 | } | |
1e8f889b | 549 | |
ac9b9c66 | 550 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
551 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
552 | if (idx >= size) | |
553 | goto backout; | |
554 | ||
83c54070 | 555 | ret = 0; |
86e5216f | 556 | if (!pte_none(*ptep)) |
4c887265 AL |
557 | goto backout; |
558 | ||
1e8f889b DG |
559 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
560 | && (vma->vm_flags & VM_SHARED))); | |
561 | set_huge_pte_at(mm, address, ptep, new_pte); | |
562 | ||
563 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
564 | /* Optimization, do the COW without a second fault */ | |
565 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
566 | } | |
567 | ||
ac9b9c66 | 568 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
569 | unlock_page(page); |
570 | out: | |
ac9b9c66 | 571 | return ret; |
4c887265 AL |
572 | |
573 | backout: | |
574 | spin_unlock(&mm->page_table_lock); | |
575 | hugetlb_put_quota(mapping); | |
576 | unlock_page(page); | |
577 | put_page(page); | |
578 | goto out; | |
ac9b9c66 HD |
579 | } |
580 | ||
86e5216f AL |
581 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
582 | unsigned long address, int write_access) | |
583 | { | |
584 | pte_t *ptep; | |
585 | pte_t entry; | |
1e8f889b | 586 | int ret; |
3935baa9 | 587 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
588 | |
589 | ptep = huge_pte_alloc(mm, address); | |
590 | if (!ptep) | |
591 | return VM_FAULT_OOM; | |
592 | ||
3935baa9 DG |
593 | /* |
594 | * Serialize hugepage allocation and instantiation, so that we don't | |
595 | * get spurious allocation failures if two CPUs race to instantiate | |
596 | * the same page in the page cache. | |
597 | */ | |
598 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 599 | entry = *ptep; |
3935baa9 DG |
600 | if (pte_none(entry)) { |
601 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
602 | mutex_unlock(&hugetlb_instantiation_mutex); | |
603 | return ret; | |
604 | } | |
86e5216f | 605 | |
83c54070 | 606 | ret = 0; |
1e8f889b DG |
607 | |
608 | spin_lock(&mm->page_table_lock); | |
609 | /* Check for a racing update before calling hugetlb_cow */ | |
610 | if (likely(pte_same(entry, *ptep))) | |
611 | if (write_access && !pte_write(entry)) | |
612 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
613 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 614 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
615 | |
616 | return ret; | |
86e5216f AL |
617 | } |
618 | ||
63551ae0 DG |
619 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
620 | struct page **pages, struct vm_area_struct **vmas, | |
621 | unsigned long *position, int *length, int i) | |
622 | { | |
d5d4b0aa KC |
623 | unsigned long pfn_offset; |
624 | unsigned long vaddr = *position; | |
63551ae0 DG |
625 | int remainder = *length; |
626 | ||
1c59827d | 627 | spin_lock(&mm->page_table_lock); |
63551ae0 | 628 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
629 | pte_t *pte; |
630 | struct page *page; | |
63551ae0 | 631 | |
4c887265 AL |
632 | /* |
633 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
634 | * each hugepage. We have to make * sure we get the | |
635 | * first, for the page indexing below to work. | |
636 | */ | |
637 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 638 | |
4c887265 AL |
639 | if (!pte || pte_none(*pte)) { |
640 | int ret; | |
63551ae0 | 641 | |
4c887265 AL |
642 | spin_unlock(&mm->page_table_lock); |
643 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
644 | spin_lock(&mm->page_table_lock); | |
83c54070 | 645 | if (!(ret & VM_FAULT_MAJOR)) |
4c887265 | 646 | continue; |
63551ae0 | 647 | |
4c887265 AL |
648 | remainder = 0; |
649 | if (!i) | |
650 | i = -EFAULT; | |
651 | break; | |
652 | } | |
653 | ||
d5d4b0aa KC |
654 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
655 | page = pte_page(*pte); | |
656 | same_page: | |
d6692183 KC |
657 | if (pages) { |
658 | get_page(page); | |
d5d4b0aa | 659 | pages[i] = page + pfn_offset; |
d6692183 | 660 | } |
63551ae0 DG |
661 | |
662 | if (vmas) | |
663 | vmas[i] = vma; | |
664 | ||
665 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 666 | ++pfn_offset; |
63551ae0 DG |
667 | --remainder; |
668 | ++i; | |
d5d4b0aa KC |
669 | if (vaddr < vma->vm_end && remainder && |
670 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
671 | /* | |
672 | * We use pfn_offset to avoid touching the pageframes | |
673 | * of this compound page. | |
674 | */ | |
675 | goto same_page; | |
676 | } | |
63551ae0 | 677 | } |
1c59827d | 678 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
679 | *length = remainder; |
680 | *position = vaddr; | |
681 | ||
682 | return i; | |
683 | } | |
8f860591 ZY |
684 | |
685 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
686 | unsigned long address, unsigned long end, pgprot_t newprot) | |
687 | { | |
688 | struct mm_struct *mm = vma->vm_mm; | |
689 | unsigned long start = address; | |
690 | pte_t *ptep; | |
691 | pte_t pte; | |
692 | ||
693 | BUG_ON(address >= end); | |
694 | flush_cache_range(vma, address, end); | |
695 | ||
39dde65c | 696 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
697 | spin_lock(&mm->page_table_lock); |
698 | for (; address < end; address += HPAGE_SIZE) { | |
699 | ptep = huge_pte_offset(mm, address); | |
700 | if (!ptep) | |
701 | continue; | |
39dde65c KC |
702 | if (huge_pmd_unshare(mm, &address, ptep)) |
703 | continue; | |
8f860591 ZY |
704 | if (!pte_none(*ptep)) { |
705 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
706 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
707 | set_huge_pte_at(mm, address, ptep, pte); | |
708 | lazy_mmu_prot_update(pte); | |
709 | } | |
710 | } | |
711 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 712 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
713 | |
714 | flush_tlb_range(vma, start, end); | |
715 | } | |
716 | ||
a43a8c39 KC |
717 | struct file_region { |
718 | struct list_head link; | |
719 | long from; | |
720 | long to; | |
721 | }; | |
722 | ||
723 | static long region_add(struct list_head *head, long f, long t) | |
724 | { | |
725 | struct file_region *rg, *nrg, *trg; | |
726 | ||
727 | /* Locate the region we are either in or before. */ | |
728 | list_for_each_entry(rg, head, link) | |
729 | if (f <= rg->to) | |
730 | break; | |
731 | ||
732 | /* Round our left edge to the current segment if it encloses us. */ | |
733 | if (f > rg->from) | |
734 | f = rg->from; | |
735 | ||
736 | /* Check for and consume any regions we now overlap with. */ | |
737 | nrg = rg; | |
738 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
739 | if (&rg->link == head) | |
740 | break; | |
741 | if (rg->from > t) | |
742 | break; | |
743 | ||
744 | /* If this area reaches higher then extend our area to | |
745 | * include it completely. If this is not the first area | |
746 | * which we intend to reuse, free it. */ | |
747 | if (rg->to > t) | |
748 | t = rg->to; | |
749 | if (rg != nrg) { | |
750 | list_del(&rg->link); | |
751 | kfree(rg); | |
752 | } | |
753 | } | |
754 | nrg->from = f; | |
755 | nrg->to = t; | |
756 | return 0; | |
757 | } | |
758 | ||
759 | static long region_chg(struct list_head *head, long f, long t) | |
760 | { | |
761 | struct file_region *rg, *nrg; | |
762 | long chg = 0; | |
763 | ||
764 | /* Locate the region we are before or in. */ | |
765 | list_for_each_entry(rg, head, link) | |
766 | if (f <= rg->to) | |
767 | break; | |
768 | ||
769 | /* If we are below the current region then a new region is required. | |
770 | * Subtle, allocate a new region at the position but make it zero | |
771 | * size such that we can guarentee to record the reservation. */ | |
772 | if (&rg->link == head || t < rg->from) { | |
773 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
774 | if (nrg == 0) | |
775 | return -ENOMEM; | |
776 | nrg->from = f; | |
777 | nrg->to = f; | |
778 | INIT_LIST_HEAD(&nrg->link); | |
779 | list_add(&nrg->link, rg->link.prev); | |
780 | ||
781 | return t - f; | |
782 | } | |
783 | ||
784 | /* Round our left edge to the current segment if it encloses us. */ | |
785 | if (f > rg->from) | |
786 | f = rg->from; | |
787 | chg = t - f; | |
788 | ||
789 | /* Check for and consume any regions we now overlap with. */ | |
790 | list_for_each_entry(rg, rg->link.prev, link) { | |
791 | if (&rg->link == head) | |
792 | break; | |
793 | if (rg->from > t) | |
794 | return chg; | |
795 | ||
796 | /* We overlap with this area, if it extends futher than | |
797 | * us then we must extend ourselves. Account for its | |
798 | * existing reservation. */ | |
799 | if (rg->to > t) { | |
800 | chg += rg->to - t; | |
801 | t = rg->to; | |
802 | } | |
803 | chg -= rg->to - rg->from; | |
804 | } | |
805 | return chg; | |
806 | } | |
807 | ||
808 | static long region_truncate(struct list_head *head, long end) | |
809 | { | |
810 | struct file_region *rg, *trg; | |
811 | long chg = 0; | |
812 | ||
813 | /* Locate the region we are either in or before. */ | |
814 | list_for_each_entry(rg, head, link) | |
815 | if (end <= rg->to) | |
816 | break; | |
817 | if (&rg->link == head) | |
818 | return 0; | |
819 | ||
820 | /* If we are in the middle of a region then adjust it. */ | |
821 | if (end > rg->from) { | |
822 | chg = rg->to - end; | |
823 | rg->to = end; | |
824 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
825 | } | |
826 | ||
827 | /* Drop any remaining regions. */ | |
828 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
829 | if (&rg->link == head) | |
830 | break; | |
831 | chg += rg->to - rg->from; | |
832 | list_del(&rg->link); | |
833 | kfree(rg); | |
834 | } | |
835 | return chg; | |
836 | } | |
837 | ||
838 | static int hugetlb_acct_memory(long delta) | |
839 | { | |
840 | int ret = -ENOMEM; | |
841 | ||
842 | spin_lock(&hugetlb_lock); | |
843 | if ((delta + resv_huge_pages) <= free_huge_pages) { | |
844 | resv_huge_pages += delta; | |
845 | ret = 0; | |
846 | } | |
847 | spin_unlock(&hugetlb_lock); | |
848 | return ret; | |
849 | } | |
850 | ||
851 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
852 | { | |
853 | long ret, chg; | |
854 | ||
855 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
856 | if (chg < 0) | |
857 | return chg; | |
8a630112 KC |
858 | /* |
859 | * When cpuset is configured, it breaks the strict hugetlb page | |
860 | * reservation as the accounting is done on a global variable. Such | |
861 | * reservation is completely rubbish in the presence of cpuset because | |
862 | * the reservation is not checked against page availability for the | |
863 | * current cpuset. Application can still potentially OOM'ed by kernel | |
864 | * with lack of free htlb page in cpuset that the task is in. | |
865 | * Attempt to enforce strict accounting with cpuset is almost | |
866 | * impossible (or too ugly) because cpuset is too fluid that | |
867 | * task or memory node can be dynamically moved between cpusets. | |
868 | * | |
869 | * The change of semantics for shared hugetlb mapping with cpuset is | |
870 | * undesirable. However, in order to preserve some of the semantics, | |
871 | * we fall back to check against current free page availability as | |
872 | * a best attempt and hopefully to minimize the impact of changing | |
873 | * semantics that cpuset has. | |
874 | */ | |
875 | if (chg > cpuset_mems_nr(free_huge_pages_node)) | |
876 | return -ENOMEM; | |
877 | ||
a43a8c39 KC |
878 | ret = hugetlb_acct_memory(chg); |
879 | if (ret < 0) | |
880 | return ret; | |
881 | region_add(&inode->i_mapping->private_list, from, to); | |
882 | return 0; | |
883 | } | |
884 | ||
885 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
886 | { | |
887 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
888 | hugetlb_acct_memory(freed - chg); | |
889 | } |