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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * Generic hugetlb support. | |
6d49e352 | 4 | * (C) Nadia Yvette Chambers, April 2004 |
1da177e4 | 5 | */ |
1da177e4 LT |
6 | #include <linux/list.h> |
7 | #include <linux/init.h> | |
1da177e4 | 8 | #include <linux/mm.h> |
e1759c21 | 9 | #include <linux/seq_file.h> |
1da177e4 LT |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> | |
cddb8a5c | 12 | #include <linux/mmu_notifier.h> |
1da177e4 | 13 | #include <linux/nodemask.h> |
63551ae0 | 14 | #include <linux/pagemap.h> |
5da7ca86 | 15 | #include <linux/mempolicy.h> |
3b32123d | 16 | #include <linux/compiler.h> |
aea47ff3 | 17 | #include <linux/cpuset.h> |
3935baa9 | 18 | #include <linux/mutex.h> |
97ad1087 | 19 | #include <linux/memblock.h> |
a3437870 | 20 | #include <linux/sysfs.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
63489f8e | 22 | #include <linux/mmdebug.h> |
174cd4b1 | 23 | #include <linux/sched/signal.h> |
0fe6e20b | 24 | #include <linux/rmap.h> |
c6247f72 | 25 | #include <linux/string_helpers.h> |
fd6a03ed NH |
26 | #include <linux/swap.h> |
27 | #include <linux/swapops.h> | |
8382d914 | 28 | #include <linux/jhash.h> |
98fa15f3 | 29 | #include <linux/numa.h> |
ce44b015 | 30 | #include <linux/llist.h> |
d6606683 | 31 | |
63551ae0 DG |
32 | #include <asm/page.h> |
33 | #include <asm/pgtable.h> | |
24669e58 | 34 | #include <asm/tlb.h> |
63551ae0 | 35 | |
24669e58 | 36 | #include <linux/io.h> |
63551ae0 | 37 | #include <linux/hugetlb.h> |
9dd540e2 | 38 | #include <linux/hugetlb_cgroup.h> |
9a305230 | 39 | #include <linux/node.h> |
1a1aad8a | 40 | #include <linux/userfaultfd_k.h> |
ab5ac90a | 41 | #include <linux/page_owner.h> |
7835e98b | 42 | #include "internal.h" |
1da177e4 | 43 | |
c3f38a38 | 44 | int hugetlb_max_hstate __read_mostly; |
e5ff2159 AK |
45 | unsigned int default_hstate_idx; |
46 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
641844f5 NH |
47 | /* |
48 | * Minimum page order among possible hugepage sizes, set to a proper value | |
49 | * at boot time. | |
50 | */ | |
51 | static unsigned int minimum_order __read_mostly = UINT_MAX; | |
e5ff2159 | 52 | |
53ba51d2 JT |
53 | __initdata LIST_HEAD(huge_boot_pages); |
54 | ||
e5ff2159 AK |
55 | /* for command line parsing */ |
56 | static struct hstate * __initdata parsed_hstate; | |
57 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 58 | static unsigned long __initdata default_hstate_size; |
9fee021d | 59 | static bool __initdata parsed_valid_hugepagesz = true; |
e5ff2159 | 60 | |
3935baa9 | 61 | /* |
31caf665 NH |
62 | * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, |
63 | * free_huge_pages, and surplus_huge_pages. | |
3935baa9 | 64 | */ |
c3f38a38 | 65 | DEFINE_SPINLOCK(hugetlb_lock); |
0bd0f9fb | 66 | |
8382d914 DB |
67 | /* |
68 | * Serializes faults on the same logical page. This is used to | |
69 | * prevent spurious OOMs when the hugepage pool is fully utilized. | |
70 | */ | |
71 | static int num_fault_mutexes; | |
c672c7f2 | 72 | struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; |
8382d914 | 73 | |
7ca02d0a MK |
74 | /* Forward declaration */ |
75 | static int hugetlb_acct_memory(struct hstate *h, long delta); | |
76 | ||
90481622 DG |
77 | static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) |
78 | { | |
79 | bool free = (spool->count == 0) && (spool->used_hpages == 0); | |
80 | ||
81 | spin_unlock(&spool->lock); | |
82 | ||
83 | /* If no pages are used, and no other handles to the subpool | |
7ca02d0a MK |
84 | * remain, give up any reservations mased on minimum size and |
85 | * free the subpool */ | |
86 | if (free) { | |
87 | if (spool->min_hpages != -1) | |
88 | hugetlb_acct_memory(spool->hstate, | |
89 | -spool->min_hpages); | |
90481622 | 90 | kfree(spool); |
7ca02d0a | 91 | } |
90481622 DG |
92 | } |
93 | ||
7ca02d0a MK |
94 | struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, |
95 | long min_hpages) | |
90481622 DG |
96 | { |
97 | struct hugepage_subpool *spool; | |
98 | ||
c6a91820 | 99 | spool = kzalloc(sizeof(*spool), GFP_KERNEL); |
90481622 DG |
100 | if (!spool) |
101 | return NULL; | |
102 | ||
103 | spin_lock_init(&spool->lock); | |
104 | spool->count = 1; | |
7ca02d0a MK |
105 | spool->max_hpages = max_hpages; |
106 | spool->hstate = h; | |
107 | spool->min_hpages = min_hpages; | |
108 | ||
109 | if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { | |
110 | kfree(spool); | |
111 | return NULL; | |
112 | } | |
113 | spool->rsv_hpages = min_hpages; | |
90481622 DG |
114 | |
115 | return spool; | |
116 | } | |
117 | ||
118 | void hugepage_put_subpool(struct hugepage_subpool *spool) | |
119 | { | |
120 | spin_lock(&spool->lock); | |
121 | BUG_ON(!spool->count); | |
122 | spool->count--; | |
123 | unlock_or_release_subpool(spool); | |
124 | } | |
125 | ||
1c5ecae3 MK |
126 | /* |
127 | * Subpool accounting for allocating and reserving pages. | |
128 | * Return -ENOMEM if there are not enough resources to satisfy the | |
129 | * the request. Otherwise, return the number of pages by which the | |
130 | * global pools must be adjusted (upward). The returned value may | |
131 | * only be different than the passed value (delta) in the case where | |
132 | * a subpool minimum size must be manitained. | |
133 | */ | |
134 | static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, | |
90481622 DG |
135 | long delta) |
136 | { | |
1c5ecae3 | 137 | long ret = delta; |
90481622 DG |
138 | |
139 | if (!spool) | |
1c5ecae3 | 140 | return ret; |
90481622 DG |
141 | |
142 | spin_lock(&spool->lock); | |
1c5ecae3 MK |
143 | |
144 | if (spool->max_hpages != -1) { /* maximum size accounting */ | |
145 | if ((spool->used_hpages + delta) <= spool->max_hpages) | |
146 | spool->used_hpages += delta; | |
147 | else { | |
148 | ret = -ENOMEM; | |
149 | goto unlock_ret; | |
150 | } | |
90481622 | 151 | } |
90481622 | 152 | |
09a95e29 MK |
153 | /* minimum size accounting */ |
154 | if (spool->min_hpages != -1 && spool->rsv_hpages) { | |
1c5ecae3 MK |
155 | if (delta > spool->rsv_hpages) { |
156 | /* | |
157 | * Asking for more reserves than those already taken on | |
158 | * behalf of subpool. Return difference. | |
159 | */ | |
160 | ret = delta - spool->rsv_hpages; | |
161 | spool->rsv_hpages = 0; | |
162 | } else { | |
163 | ret = 0; /* reserves already accounted for */ | |
164 | spool->rsv_hpages -= delta; | |
165 | } | |
166 | } | |
167 | ||
168 | unlock_ret: | |
169 | spin_unlock(&spool->lock); | |
90481622 DG |
170 | return ret; |
171 | } | |
172 | ||
1c5ecae3 MK |
173 | /* |
174 | * Subpool accounting for freeing and unreserving pages. | |
175 | * Return the number of global page reservations that must be dropped. | |
176 | * The return value may only be different than the passed value (delta) | |
177 | * in the case where a subpool minimum size must be maintained. | |
178 | */ | |
179 | static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, | |
90481622 DG |
180 | long delta) |
181 | { | |
1c5ecae3 MK |
182 | long ret = delta; |
183 | ||
90481622 | 184 | if (!spool) |
1c5ecae3 | 185 | return delta; |
90481622 DG |
186 | |
187 | spin_lock(&spool->lock); | |
1c5ecae3 MK |
188 | |
189 | if (spool->max_hpages != -1) /* maximum size accounting */ | |
190 | spool->used_hpages -= delta; | |
191 | ||
09a95e29 MK |
192 | /* minimum size accounting */ |
193 | if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { | |
1c5ecae3 MK |
194 | if (spool->rsv_hpages + delta <= spool->min_hpages) |
195 | ret = 0; | |
196 | else | |
197 | ret = spool->rsv_hpages + delta - spool->min_hpages; | |
198 | ||
199 | spool->rsv_hpages += delta; | |
200 | if (spool->rsv_hpages > spool->min_hpages) | |
201 | spool->rsv_hpages = spool->min_hpages; | |
202 | } | |
203 | ||
204 | /* | |
205 | * If hugetlbfs_put_super couldn't free spool due to an outstanding | |
206 | * quota reference, free it now. | |
207 | */ | |
90481622 | 208 | unlock_or_release_subpool(spool); |
1c5ecae3 MK |
209 | |
210 | return ret; | |
90481622 DG |
211 | } |
212 | ||
213 | static inline struct hugepage_subpool *subpool_inode(struct inode *inode) | |
214 | { | |
215 | return HUGETLBFS_SB(inode->i_sb)->spool; | |
216 | } | |
217 | ||
218 | static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) | |
219 | { | |
496ad9aa | 220 | return subpool_inode(file_inode(vma->vm_file)); |
90481622 DG |
221 | } |
222 | ||
96822904 AW |
223 | /* |
224 | * Region tracking -- allows tracking of reservations and instantiated pages | |
225 | * across the pages in a mapping. | |
84afd99b | 226 | * |
1dd308a7 MK |
227 | * The region data structures are embedded into a resv_map and protected |
228 | * by a resv_map's lock. The set of regions within the resv_map represent | |
229 | * reservations for huge pages, or huge pages that have already been | |
230 | * instantiated within the map. The from and to elements are huge page | |
231 | * indicies into the associated mapping. from indicates the starting index | |
232 | * of the region. to represents the first index past the end of the region. | |
233 | * | |
234 | * For example, a file region structure with from == 0 and to == 4 represents | |
235 | * four huge pages in a mapping. It is important to note that the to element | |
236 | * represents the first element past the end of the region. This is used in | |
237 | * arithmetic as 4(to) - 0(from) = 4 huge pages in the region. | |
238 | * | |
239 | * Interval notation of the form [from, to) will be used to indicate that | |
240 | * the endpoint from is inclusive and to is exclusive. | |
96822904 AW |
241 | */ |
242 | struct file_region { | |
243 | struct list_head link; | |
244 | long from; | |
245 | long to; | |
246 | }; | |
247 | ||
1dd308a7 MK |
248 | /* |
249 | * Add the huge page range represented by [f, t) to the reserve | |
5e911373 MK |
250 | * map. In the normal case, existing regions will be expanded |
251 | * to accommodate the specified range. Sufficient regions should | |
252 | * exist for expansion due to the previous call to region_chg | |
253 | * with the same range. However, it is possible that region_del | |
254 | * could have been called after region_chg and modifed the map | |
255 | * in such a way that no region exists to be expanded. In this | |
256 | * case, pull a region descriptor from the cache associated with | |
257 | * the map and use that for the new range. | |
cf3ad20b MK |
258 | * |
259 | * Return the number of new huge pages added to the map. This | |
260 | * number is greater than or equal to zero. | |
1dd308a7 | 261 | */ |
1406ec9b | 262 | static long region_add(struct resv_map *resv, long f, long t) |
96822904 | 263 | { |
1406ec9b | 264 | struct list_head *head = &resv->regions; |
96822904 | 265 | struct file_region *rg, *nrg, *trg; |
cf3ad20b | 266 | long add = 0; |
96822904 | 267 | |
7b24d861 | 268 | spin_lock(&resv->lock); |
96822904 AW |
269 | /* Locate the region we are either in or before. */ |
270 | list_for_each_entry(rg, head, link) | |
271 | if (f <= rg->to) | |
272 | break; | |
273 | ||
5e911373 MK |
274 | /* |
275 | * If no region exists which can be expanded to include the | |
276 | * specified range, the list must have been modified by an | |
277 | * interleving call to region_del(). Pull a region descriptor | |
278 | * from the cache and use it for this range. | |
279 | */ | |
280 | if (&rg->link == head || t < rg->from) { | |
281 | VM_BUG_ON(resv->region_cache_count <= 0); | |
282 | ||
283 | resv->region_cache_count--; | |
284 | nrg = list_first_entry(&resv->region_cache, struct file_region, | |
285 | link); | |
286 | list_del(&nrg->link); | |
287 | ||
288 | nrg->from = f; | |
289 | nrg->to = t; | |
290 | list_add(&nrg->link, rg->link.prev); | |
291 | ||
292 | add += t - f; | |
293 | goto out_locked; | |
294 | } | |
295 | ||
96822904 AW |
296 | /* Round our left edge to the current segment if it encloses us. */ |
297 | if (f > rg->from) | |
298 | f = rg->from; | |
299 | ||
300 | /* Check for and consume any regions we now overlap with. */ | |
301 | nrg = rg; | |
302 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
303 | if (&rg->link == head) | |
304 | break; | |
305 | if (rg->from > t) | |
306 | break; | |
307 | ||
308 | /* If this area reaches higher then extend our area to | |
309 | * include it completely. If this is not the first area | |
310 | * which we intend to reuse, free it. */ | |
311 | if (rg->to > t) | |
312 | t = rg->to; | |
313 | if (rg != nrg) { | |
cf3ad20b MK |
314 | /* Decrement return value by the deleted range. |
315 | * Another range will span this area so that by | |
316 | * end of routine add will be >= zero | |
317 | */ | |
318 | add -= (rg->to - rg->from); | |
96822904 AW |
319 | list_del(&rg->link); |
320 | kfree(rg); | |
321 | } | |
322 | } | |
cf3ad20b MK |
323 | |
324 | add += (nrg->from - f); /* Added to beginning of region */ | |
96822904 | 325 | nrg->from = f; |
cf3ad20b | 326 | add += t - nrg->to; /* Added to end of region */ |
96822904 | 327 | nrg->to = t; |
cf3ad20b | 328 | |
5e911373 MK |
329 | out_locked: |
330 | resv->adds_in_progress--; | |
7b24d861 | 331 | spin_unlock(&resv->lock); |
cf3ad20b MK |
332 | VM_BUG_ON(add < 0); |
333 | return add; | |
96822904 AW |
334 | } |
335 | ||
1dd308a7 MK |
336 | /* |
337 | * Examine the existing reserve map and determine how many | |
338 | * huge pages in the specified range [f, t) are NOT currently | |
339 | * represented. This routine is called before a subsequent | |
340 | * call to region_add that will actually modify the reserve | |
341 | * map to add the specified range [f, t). region_chg does | |
342 | * not change the number of huge pages represented by the | |
343 | * map. However, if the existing regions in the map can not | |
344 | * be expanded to represent the new range, a new file_region | |
345 | * structure is added to the map as a placeholder. This is | |
346 | * so that the subsequent region_add call will have all the | |
347 | * regions it needs and will not fail. | |
348 | * | |
5e911373 MK |
349 | * Upon entry, region_chg will also examine the cache of region descriptors |
350 | * associated with the map. If there are not enough descriptors cached, one | |
351 | * will be allocated for the in progress add operation. | |
352 | * | |
353 | * Returns the number of huge pages that need to be added to the existing | |
354 | * reservation map for the range [f, t). This number is greater or equal to | |
355 | * zero. -ENOMEM is returned if a new file_region structure or cache entry | |
356 | * is needed and can not be allocated. | |
1dd308a7 | 357 | */ |
1406ec9b | 358 | static long region_chg(struct resv_map *resv, long f, long t) |
96822904 | 359 | { |
1406ec9b | 360 | struct list_head *head = &resv->regions; |
7b24d861 | 361 | struct file_region *rg, *nrg = NULL; |
96822904 AW |
362 | long chg = 0; |
363 | ||
7b24d861 DB |
364 | retry: |
365 | spin_lock(&resv->lock); | |
5e911373 MK |
366 | retry_locked: |
367 | resv->adds_in_progress++; | |
368 | ||
369 | /* | |
370 | * Check for sufficient descriptors in the cache to accommodate | |
371 | * the number of in progress add operations. | |
372 | */ | |
373 | if (resv->adds_in_progress > resv->region_cache_count) { | |
374 | struct file_region *trg; | |
375 | ||
376 | VM_BUG_ON(resv->adds_in_progress - resv->region_cache_count > 1); | |
377 | /* Must drop lock to allocate a new descriptor. */ | |
378 | resv->adds_in_progress--; | |
379 | spin_unlock(&resv->lock); | |
380 | ||
381 | trg = kmalloc(sizeof(*trg), GFP_KERNEL); | |
dbe409e4 MK |
382 | if (!trg) { |
383 | kfree(nrg); | |
5e911373 | 384 | return -ENOMEM; |
dbe409e4 | 385 | } |
5e911373 MK |
386 | |
387 | spin_lock(&resv->lock); | |
388 | list_add(&trg->link, &resv->region_cache); | |
389 | resv->region_cache_count++; | |
390 | goto retry_locked; | |
391 | } | |
392 | ||
96822904 AW |
393 | /* Locate the region we are before or in. */ |
394 | list_for_each_entry(rg, head, link) | |
395 | if (f <= rg->to) | |
396 | break; | |
397 | ||
398 | /* If we are below the current region then a new region is required. | |
399 | * Subtle, allocate a new region at the position but make it zero | |
400 | * size such that we can guarantee to record the reservation. */ | |
401 | if (&rg->link == head || t < rg->from) { | |
7b24d861 | 402 | if (!nrg) { |
5e911373 | 403 | resv->adds_in_progress--; |
7b24d861 DB |
404 | spin_unlock(&resv->lock); |
405 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
406 | if (!nrg) | |
407 | return -ENOMEM; | |
408 | ||
409 | nrg->from = f; | |
410 | nrg->to = f; | |
411 | INIT_LIST_HEAD(&nrg->link); | |
412 | goto retry; | |
413 | } | |
96822904 | 414 | |
7b24d861 DB |
415 | list_add(&nrg->link, rg->link.prev); |
416 | chg = t - f; | |
417 | goto out_nrg; | |
96822904 AW |
418 | } |
419 | ||
420 | /* Round our left edge to the current segment if it encloses us. */ | |
421 | if (f > rg->from) | |
422 | f = rg->from; | |
423 | chg = t - f; | |
424 | ||
425 | /* Check for and consume any regions we now overlap with. */ | |
426 | list_for_each_entry(rg, rg->link.prev, link) { | |
427 | if (&rg->link == head) | |
428 | break; | |
429 | if (rg->from > t) | |
7b24d861 | 430 | goto out; |
96822904 | 431 | |
25985edc | 432 | /* We overlap with this area, if it extends further than |
96822904 AW |
433 | * us then we must extend ourselves. Account for its |
434 | * existing reservation. */ | |
435 | if (rg->to > t) { | |
436 | chg += rg->to - t; | |
437 | t = rg->to; | |
438 | } | |
439 | chg -= rg->to - rg->from; | |
440 | } | |
7b24d861 DB |
441 | |
442 | out: | |
443 | spin_unlock(&resv->lock); | |
444 | /* We already know we raced and no longer need the new region */ | |
445 | kfree(nrg); | |
446 | return chg; | |
447 | out_nrg: | |
448 | spin_unlock(&resv->lock); | |
96822904 AW |
449 | return chg; |
450 | } | |
451 | ||
5e911373 MK |
452 | /* |
453 | * Abort the in progress add operation. The adds_in_progress field | |
454 | * of the resv_map keeps track of the operations in progress between | |
455 | * calls to region_chg and region_add. Operations are sometimes | |
456 | * aborted after the call to region_chg. In such cases, region_abort | |
457 | * is called to decrement the adds_in_progress counter. | |
458 | * | |
459 | * NOTE: The range arguments [f, t) are not needed or used in this | |
460 | * routine. They are kept to make reading the calling code easier as | |
461 | * arguments will match the associated region_chg call. | |
462 | */ | |
463 | static void region_abort(struct resv_map *resv, long f, long t) | |
464 | { | |
465 | spin_lock(&resv->lock); | |
466 | VM_BUG_ON(!resv->region_cache_count); | |
467 | resv->adds_in_progress--; | |
468 | spin_unlock(&resv->lock); | |
469 | } | |
470 | ||
1dd308a7 | 471 | /* |
feba16e2 MK |
472 | * Delete the specified range [f, t) from the reserve map. If the |
473 | * t parameter is LONG_MAX, this indicates that ALL regions after f | |
474 | * should be deleted. Locate the regions which intersect [f, t) | |
475 | * and either trim, delete or split the existing regions. | |
476 | * | |
477 | * Returns the number of huge pages deleted from the reserve map. | |
478 | * In the normal case, the return value is zero or more. In the | |
479 | * case where a region must be split, a new region descriptor must | |
480 | * be allocated. If the allocation fails, -ENOMEM will be returned. | |
481 | * NOTE: If the parameter t == LONG_MAX, then we will never split | |
482 | * a region and possibly return -ENOMEM. Callers specifying | |
483 | * t == LONG_MAX do not need to check for -ENOMEM error. | |
1dd308a7 | 484 | */ |
feba16e2 | 485 | static long region_del(struct resv_map *resv, long f, long t) |
96822904 | 486 | { |
1406ec9b | 487 | struct list_head *head = &resv->regions; |
96822904 | 488 | struct file_region *rg, *trg; |
feba16e2 MK |
489 | struct file_region *nrg = NULL; |
490 | long del = 0; | |
96822904 | 491 | |
feba16e2 | 492 | retry: |
7b24d861 | 493 | spin_lock(&resv->lock); |
feba16e2 | 494 | list_for_each_entry_safe(rg, trg, head, link) { |
dbe409e4 MK |
495 | /* |
496 | * Skip regions before the range to be deleted. file_region | |
497 | * ranges are normally of the form [from, to). However, there | |
498 | * may be a "placeholder" entry in the map which is of the form | |
499 | * (from, to) with from == to. Check for placeholder entries | |
500 | * at the beginning of the range to be deleted. | |
501 | */ | |
502 | if (rg->to <= f && (rg->to != rg->from || rg->to != f)) | |
feba16e2 | 503 | continue; |
dbe409e4 | 504 | |
feba16e2 | 505 | if (rg->from >= t) |
96822904 | 506 | break; |
96822904 | 507 | |
feba16e2 MK |
508 | if (f > rg->from && t < rg->to) { /* Must split region */ |
509 | /* | |
510 | * Check for an entry in the cache before dropping | |
511 | * lock and attempting allocation. | |
512 | */ | |
513 | if (!nrg && | |
514 | resv->region_cache_count > resv->adds_in_progress) { | |
515 | nrg = list_first_entry(&resv->region_cache, | |
516 | struct file_region, | |
517 | link); | |
518 | list_del(&nrg->link); | |
519 | resv->region_cache_count--; | |
520 | } | |
96822904 | 521 | |
feba16e2 MK |
522 | if (!nrg) { |
523 | spin_unlock(&resv->lock); | |
524 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
525 | if (!nrg) | |
526 | return -ENOMEM; | |
527 | goto retry; | |
528 | } | |
529 | ||
530 | del += t - f; | |
531 | ||
532 | /* New entry for end of split region */ | |
533 | nrg->from = t; | |
534 | nrg->to = rg->to; | |
535 | INIT_LIST_HEAD(&nrg->link); | |
536 | ||
537 | /* Original entry is trimmed */ | |
538 | rg->to = f; | |
539 | ||
540 | list_add(&nrg->link, &rg->link); | |
541 | nrg = NULL; | |
96822904 | 542 | break; |
feba16e2 MK |
543 | } |
544 | ||
545 | if (f <= rg->from && t >= rg->to) { /* Remove entire region */ | |
546 | del += rg->to - rg->from; | |
547 | list_del(&rg->link); | |
548 | kfree(rg); | |
549 | continue; | |
550 | } | |
551 | ||
552 | if (f <= rg->from) { /* Trim beginning of region */ | |
553 | del += t - rg->from; | |
554 | rg->from = t; | |
555 | } else { /* Trim end of region */ | |
556 | del += rg->to - f; | |
557 | rg->to = f; | |
558 | } | |
96822904 | 559 | } |
7b24d861 | 560 | |
7b24d861 | 561 | spin_unlock(&resv->lock); |
feba16e2 MK |
562 | kfree(nrg); |
563 | return del; | |
96822904 AW |
564 | } |
565 | ||
b5cec28d MK |
566 | /* |
567 | * A rare out of memory error was encountered which prevented removal of | |
568 | * the reserve map region for a page. The huge page itself was free'ed | |
569 | * and removed from the page cache. This routine will adjust the subpool | |
570 | * usage count, and the global reserve count if needed. By incrementing | |
571 | * these counts, the reserve map entry which could not be deleted will | |
572 | * appear as a "reserved" entry instead of simply dangling with incorrect | |
573 | * counts. | |
574 | */ | |
72e2936c | 575 | void hugetlb_fix_reserve_counts(struct inode *inode) |
b5cec28d MK |
576 | { |
577 | struct hugepage_subpool *spool = subpool_inode(inode); | |
578 | long rsv_adjust; | |
579 | ||
580 | rsv_adjust = hugepage_subpool_get_pages(spool, 1); | |
72e2936c | 581 | if (rsv_adjust) { |
b5cec28d MK |
582 | struct hstate *h = hstate_inode(inode); |
583 | ||
584 | hugetlb_acct_memory(h, 1); | |
585 | } | |
586 | } | |
587 | ||
1dd308a7 MK |
588 | /* |
589 | * Count and return the number of huge pages in the reserve map | |
590 | * that intersect with the range [f, t). | |
591 | */ | |
1406ec9b | 592 | static long region_count(struct resv_map *resv, long f, long t) |
84afd99b | 593 | { |
1406ec9b | 594 | struct list_head *head = &resv->regions; |
84afd99b AW |
595 | struct file_region *rg; |
596 | long chg = 0; | |
597 | ||
7b24d861 | 598 | spin_lock(&resv->lock); |
84afd99b AW |
599 | /* Locate each segment we overlap with, and count that overlap. */ |
600 | list_for_each_entry(rg, head, link) { | |
f2135a4a WSH |
601 | long seg_from; |
602 | long seg_to; | |
84afd99b AW |
603 | |
604 | if (rg->to <= f) | |
605 | continue; | |
606 | if (rg->from >= t) | |
607 | break; | |
608 | ||
609 | seg_from = max(rg->from, f); | |
610 | seg_to = min(rg->to, t); | |
611 | ||
612 | chg += seg_to - seg_from; | |
613 | } | |
7b24d861 | 614 | spin_unlock(&resv->lock); |
84afd99b AW |
615 | |
616 | return chg; | |
617 | } | |
618 | ||
e7c4b0bf AW |
619 | /* |
620 | * Convert the address within this vma to the page offset within | |
621 | * the mapping, in pagecache page units; huge pages here. | |
622 | */ | |
a5516438 AK |
623 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
624 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 625 | { |
a5516438 AK |
626 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
627 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
628 | } |
629 | ||
0fe6e20b NH |
630 | pgoff_t linear_hugepage_index(struct vm_area_struct *vma, |
631 | unsigned long address) | |
632 | { | |
633 | return vma_hugecache_offset(hstate_vma(vma), vma, address); | |
634 | } | |
dee41079 | 635 | EXPORT_SYMBOL_GPL(linear_hugepage_index); |
0fe6e20b | 636 | |
08fba699 MG |
637 | /* |
638 | * Return the size of the pages allocated when backing a VMA. In the majority | |
639 | * cases this will be same size as used by the page table entries. | |
640 | */ | |
641 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) | |
642 | { | |
05ea8860 DW |
643 | if (vma->vm_ops && vma->vm_ops->pagesize) |
644 | return vma->vm_ops->pagesize(vma); | |
645 | return PAGE_SIZE; | |
08fba699 | 646 | } |
f340ca0f | 647 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 648 | |
3340289d MG |
649 | /* |
650 | * Return the page size being used by the MMU to back a VMA. In the majority | |
651 | * of cases, the page size used by the kernel matches the MMU size. On | |
09135cc5 DW |
652 | * architectures where it differs, an architecture-specific 'strong' |
653 | * version of this symbol is required. | |
3340289d | 654 | */ |
09135cc5 | 655 | __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) |
3340289d MG |
656 | { |
657 | return vma_kernel_pagesize(vma); | |
658 | } | |
3340289d | 659 | |
84afd99b AW |
660 | /* |
661 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
662 | * bits of the reservation map pointer, which are always clear due to | |
663 | * alignment. | |
664 | */ | |
665 | #define HPAGE_RESV_OWNER (1UL << 0) | |
666 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 667 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 668 | |
a1e78772 MG |
669 | /* |
670 | * These helpers are used to track how many pages are reserved for | |
671 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
672 | * is guaranteed to have their future faults succeed. | |
673 | * | |
674 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
675 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
676 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
677 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
678 | * |
679 | * The private mapping reservation is represented in a subtly different | |
680 | * manner to a shared mapping. A shared mapping has a region map associated | |
681 | * with the underlying file, this region map represents the backing file | |
682 | * pages which have ever had a reservation assigned which this persists even | |
683 | * after the page is instantiated. A private mapping has a region map | |
684 | * associated with the original mmap which is attached to all VMAs which | |
685 | * reference it, this region map represents those offsets which have consumed | |
686 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 687 | */ |
e7c4b0bf AW |
688 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
689 | { | |
690 | return (unsigned long)vma->vm_private_data; | |
691 | } | |
692 | ||
693 | static void set_vma_private_data(struct vm_area_struct *vma, | |
694 | unsigned long value) | |
695 | { | |
696 | vma->vm_private_data = (void *)value; | |
697 | } | |
698 | ||
9119a41e | 699 | struct resv_map *resv_map_alloc(void) |
84afd99b AW |
700 | { |
701 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
5e911373 MK |
702 | struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); |
703 | ||
704 | if (!resv_map || !rg) { | |
705 | kfree(resv_map); | |
706 | kfree(rg); | |
84afd99b | 707 | return NULL; |
5e911373 | 708 | } |
84afd99b AW |
709 | |
710 | kref_init(&resv_map->refs); | |
7b24d861 | 711 | spin_lock_init(&resv_map->lock); |
84afd99b AW |
712 | INIT_LIST_HEAD(&resv_map->regions); |
713 | ||
5e911373 MK |
714 | resv_map->adds_in_progress = 0; |
715 | ||
716 | INIT_LIST_HEAD(&resv_map->region_cache); | |
717 | list_add(&rg->link, &resv_map->region_cache); | |
718 | resv_map->region_cache_count = 1; | |
719 | ||
84afd99b AW |
720 | return resv_map; |
721 | } | |
722 | ||
9119a41e | 723 | void resv_map_release(struct kref *ref) |
84afd99b AW |
724 | { |
725 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
5e911373 MK |
726 | struct list_head *head = &resv_map->region_cache; |
727 | struct file_region *rg, *trg; | |
84afd99b AW |
728 | |
729 | /* Clear out any active regions before we release the map. */ | |
feba16e2 | 730 | region_del(resv_map, 0, LONG_MAX); |
5e911373 MK |
731 | |
732 | /* ... and any entries left in the cache */ | |
733 | list_for_each_entry_safe(rg, trg, head, link) { | |
734 | list_del(&rg->link); | |
735 | kfree(rg); | |
736 | } | |
737 | ||
738 | VM_BUG_ON(resv_map->adds_in_progress); | |
739 | ||
84afd99b AW |
740 | kfree(resv_map); |
741 | } | |
742 | ||
4e35f483 JK |
743 | static inline struct resv_map *inode_resv_map(struct inode *inode) |
744 | { | |
f27a5136 MK |
745 | /* |
746 | * At inode evict time, i_mapping may not point to the original | |
747 | * address space within the inode. This original address space | |
748 | * contains the pointer to the resv_map. So, always use the | |
749 | * address space embedded within the inode. | |
750 | * The VERY common case is inode->mapping == &inode->i_data but, | |
751 | * this may not be true for device special inodes. | |
752 | */ | |
753 | return (struct resv_map *)(&inode->i_data)->private_data; | |
4e35f483 JK |
754 | } |
755 | ||
84afd99b | 756 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) |
a1e78772 | 757 | { |
81d1b09c | 758 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
4e35f483 JK |
759 | if (vma->vm_flags & VM_MAYSHARE) { |
760 | struct address_space *mapping = vma->vm_file->f_mapping; | |
761 | struct inode *inode = mapping->host; | |
762 | ||
763 | return inode_resv_map(inode); | |
764 | ||
765 | } else { | |
84afd99b AW |
766 | return (struct resv_map *)(get_vma_private_data(vma) & |
767 | ~HPAGE_RESV_MASK); | |
4e35f483 | 768 | } |
a1e78772 MG |
769 | } |
770 | ||
84afd99b | 771 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 | 772 | { |
81d1b09c SL |
773 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
774 | VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); | |
a1e78772 | 775 | |
84afd99b AW |
776 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
777 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
778 | } |
779 | ||
780 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
781 | { | |
81d1b09c SL |
782 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
783 | VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); | |
e7c4b0bf AW |
784 | |
785 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
786 | } |
787 | ||
788 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
789 | { | |
81d1b09c | 790 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
e7c4b0bf AW |
791 | |
792 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
793 | } |
794 | ||
04f2cbe3 | 795 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
796 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
797 | { | |
81d1b09c | 798 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
f83a275d | 799 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
800 | vma->vm_private_data = (void *)0; |
801 | } | |
802 | ||
803 | /* Returns true if the VMA has associated reserve pages */ | |
559ec2f8 | 804 | static bool vma_has_reserves(struct vm_area_struct *vma, long chg) |
a1e78772 | 805 | { |
af0ed73e JK |
806 | if (vma->vm_flags & VM_NORESERVE) { |
807 | /* | |
808 | * This address is already reserved by other process(chg == 0), | |
809 | * so, we should decrement reserved count. Without decrementing, | |
810 | * reserve count remains after releasing inode, because this | |
811 | * allocated page will go into page cache and is regarded as | |
812 | * coming from reserved pool in releasing step. Currently, we | |
813 | * don't have any other solution to deal with this situation | |
814 | * properly, so add work-around here. | |
815 | */ | |
816 | if (vma->vm_flags & VM_MAYSHARE && chg == 0) | |
559ec2f8 | 817 | return true; |
af0ed73e | 818 | else |
559ec2f8 | 819 | return false; |
af0ed73e | 820 | } |
a63884e9 JK |
821 | |
822 | /* Shared mappings always use reserves */ | |
1fb1b0e9 MK |
823 | if (vma->vm_flags & VM_MAYSHARE) { |
824 | /* | |
825 | * We know VM_NORESERVE is not set. Therefore, there SHOULD | |
826 | * be a region map for all pages. The only situation where | |
827 | * there is no region map is if a hole was punched via | |
828 | * fallocate. In this case, there really are no reverves to | |
829 | * use. This situation is indicated if chg != 0. | |
830 | */ | |
831 | if (chg) | |
832 | return false; | |
833 | else | |
834 | return true; | |
835 | } | |
a63884e9 JK |
836 | |
837 | /* | |
838 | * Only the process that called mmap() has reserves for | |
839 | * private mappings. | |
840 | */ | |
67961f9d MK |
841 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
842 | /* | |
843 | * Like the shared case above, a hole punch or truncate | |
844 | * could have been performed on the private mapping. | |
845 | * Examine the value of chg to determine if reserves | |
846 | * actually exist or were previously consumed. | |
847 | * Very Subtle - The value of chg comes from a previous | |
848 | * call to vma_needs_reserves(). The reserve map for | |
849 | * private mappings has different (opposite) semantics | |
850 | * than that of shared mappings. vma_needs_reserves() | |
851 | * has already taken this difference in semantics into | |
852 | * account. Therefore, the meaning of chg is the same | |
853 | * as in the shared case above. Code could easily be | |
854 | * combined, but keeping it separate draws attention to | |
855 | * subtle differences. | |
856 | */ | |
857 | if (chg) | |
858 | return false; | |
859 | else | |
860 | return true; | |
861 | } | |
a63884e9 | 862 | |
559ec2f8 | 863 | return false; |
a1e78772 MG |
864 | } |
865 | ||
a5516438 | 866 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
867 | { |
868 | int nid = page_to_nid(page); | |
0edaecfa | 869 | list_move(&page->lru, &h->hugepage_freelists[nid]); |
a5516438 AK |
870 | h->free_huge_pages++; |
871 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
872 | } |
873 | ||
94310cbc | 874 | static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) |
bf50bab2 NH |
875 | { |
876 | struct page *page; | |
877 | ||
c8721bbb | 878 | list_for_each_entry(page, &h->hugepage_freelists[nid], lru) |
243abd5b | 879 | if (!PageHWPoison(page)) |
c8721bbb NH |
880 | break; |
881 | /* | |
882 | * if 'non-isolated free hugepage' not found on the list, | |
883 | * the allocation fails. | |
884 | */ | |
885 | if (&h->hugepage_freelists[nid] == &page->lru) | |
bf50bab2 | 886 | return NULL; |
0edaecfa | 887 | list_move(&page->lru, &h->hugepage_activelist); |
a9869b83 | 888 | set_page_refcounted(page); |
bf50bab2 NH |
889 | h->free_huge_pages--; |
890 | h->free_huge_pages_node[nid]--; | |
891 | return page; | |
892 | } | |
893 | ||
3e59fcb0 MH |
894 | static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, |
895 | nodemask_t *nmask) | |
94310cbc | 896 | { |
3e59fcb0 MH |
897 | unsigned int cpuset_mems_cookie; |
898 | struct zonelist *zonelist; | |
899 | struct zone *zone; | |
900 | struct zoneref *z; | |
98fa15f3 | 901 | int node = NUMA_NO_NODE; |
94310cbc | 902 | |
3e59fcb0 MH |
903 | zonelist = node_zonelist(nid, gfp_mask); |
904 | ||
905 | retry_cpuset: | |
906 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
907 | for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { | |
908 | struct page *page; | |
909 | ||
910 | if (!cpuset_zone_allowed(zone, gfp_mask)) | |
911 | continue; | |
912 | /* | |
913 | * no need to ask again on the same node. Pool is node rather than | |
914 | * zone aware | |
915 | */ | |
916 | if (zone_to_nid(zone) == node) | |
917 | continue; | |
918 | node = zone_to_nid(zone); | |
94310cbc | 919 | |
94310cbc AK |
920 | page = dequeue_huge_page_node_exact(h, node); |
921 | if (page) | |
922 | return page; | |
923 | } | |
3e59fcb0 MH |
924 | if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) |
925 | goto retry_cpuset; | |
926 | ||
94310cbc AK |
927 | return NULL; |
928 | } | |
929 | ||
86cdb465 NH |
930 | /* Movability of hugepages depends on migration support. */ |
931 | static inline gfp_t htlb_alloc_mask(struct hstate *h) | |
932 | { | |
7ed2c31d | 933 | if (hugepage_movable_supported(h)) |
86cdb465 NH |
934 | return GFP_HIGHUSER_MOVABLE; |
935 | else | |
936 | return GFP_HIGHUSER; | |
937 | } | |
938 | ||
a5516438 AK |
939 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
940 | struct vm_area_struct *vma, | |
af0ed73e JK |
941 | unsigned long address, int avoid_reserve, |
942 | long chg) | |
1da177e4 | 943 | { |
3e59fcb0 | 944 | struct page *page; |
480eccf9 | 945 | struct mempolicy *mpol; |
04ec6264 | 946 | gfp_t gfp_mask; |
3e59fcb0 | 947 | nodemask_t *nodemask; |
04ec6264 | 948 | int nid; |
1da177e4 | 949 | |
a1e78772 MG |
950 | /* |
951 | * A child process with MAP_PRIVATE mappings created by their parent | |
952 | * have no page reserves. This check ensures that reservations are | |
953 | * not "stolen". The child may still get SIGKILLed | |
954 | */ | |
af0ed73e | 955 | if (!vma_has_reserves(vma, chg) && |
a5516438 | 956 | h->free_huge_pages - h->resv_huge_pages == 0) |
c0ff7453 | 957 | goto err; |
a1e78772 | 958 | |
04f2cbe3 | 959 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 960 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
6eab04a8 | 961 | goto err; |
04f2cbe3 | 962 | |
04ec6264 VB |
963 | gfp_mask = htlb_alloc_mask(h); |
964 | nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); | |
3e59fcb0 MH |
965 | page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); |
966 | if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { | |
967 | SetPagePrivate(page); | |
968 | h->resv_huge_pages--; | |
1da177e4 | 969 | } |
cc9a6c87 | 970 | |
52cd3b07 | 971 | mpol_cond_put(mpol); |
1da177e4 | 972 | return page; |
cc9a6c87 MG |
973 | |
974 | err: | |
cc9a6c87 | 975 | return NULL; |
1da177e4 LT |
976 | } |
977 | ||
1cac6f2c LC |
978 | /* |
979 | * common helper functions for hstate_next_node_to_{alloc|free}. | |
980 | * We may have allocated or freed a huge page based on a different | |
981 | * nodes_allowed previously, so h->next_node_to_{alloc|free} might | |
982 | * be outside of *nodes_allowed. Ensure that we use an allowed | |
983 | * node for alloc or free. | |
984 | */ | |
985 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) | |
986 | { | |
0edaf86c | 987 | nid = next_node_in(nid, *nodes_allowed); |
1cac6f2c LC |
988 | VM_BUG_ON(nid >= MAX_NUMNODES); |
989 | ||
990 | return nid; | |
991 | } | |
992 | ||
993 | static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) | |
994 | { | |
995 | if (!node_isset(nid, *nodes_allowed)) | |
996 | nid = next_node_allowed(nid, nodes_allowed); | |
997 | return nid; | |
998 | } | |
999 | ||
1000 | /* | |
1001 | * returns the previously saved node ["this node"] from which to | |
1002 | * allocate a persistent huge page for the pool and advance the | |
1003 | * next node from which to allocate, handling wrap at end of node | |
1004 | * mask. | |
1005 | */ | |
1006 | static int hstate_next_node_to_alloc(struct hstate *h, | |
1007 | nodemask_t *nodes_allowed) | |
1008 | { | |
1009 | int nid; | |
1010 | ||
1011 | VM_BUG_ON(!nodes_allowed); | |
1012 | ||
1013 | nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); | |
1014 | h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); | |
1015 | ||
1016 | return nid; | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * helper for free_pool_huge_page() - return the previously saved | |
1021 | * node ["this node"] from which to free a huge page. Advance the | |
1022 | * next node id whether or not we find a free huge page to free so | |
1023 | * that the next attempt to free addresses the next node. | |
1024 | */ | |
1025 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) | |
1026 | { | |
1027 | int nid; | |
1028 | ||
1029 | VM_BUG_ON(!nodes_allowed); | |
1030 | ||
1031 | nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); | |
1032 | h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); | |
1033 | ||
1034 | return nid; | |
1035 | } | |
1036 | ||
1037 | #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ | |
1038 | for (nr_nodes = nodes_weight(*mask); \ | |
1039 | nr_nodes > 0 && \ | |
1040 | ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ | |
1041 | nr_nodes--) | |
1042 | ||
1043 | #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ | |
1044 | for (nr_nodes = nodes_weight(*mask); \ | |
1045 | nr_nodes > 0 && \ | |
1046 | ((node = hstate_next_node_to_free(hs, mask)) || 1); \ | |
1047 | nr_nodes--) | |
1048 | ||
e1073d1e | 1049 | #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE |
944d9fec | 1050 | static void destroy_compound_gigantic_page(struct page *page, |
d00181b9 | 1051 | unsigned int order) |
944d9fec LC |
1052 | { |
1053 | int i; | |
1054 | int nr_pages = 1 << order; | |
1055 | struct page *p = page + 1; | |
1056 | ||
c8cc708a | 1057 | atomic_set(compound_mapcount_ptr(page), 0); |
944d9fec | 1058 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
1d798ca3 | 1059 | clear_compound_head(p); |
944d9fec | 1060 | set_page_refcounted(p); |
944d9fec LC |
1061 | } |
1062 | ||
1063 | set_compound_order(page, 0); | |
1064 | __ClearPageHead(page); | |
1065 | } | |
1066 | ||
d00181b9 | 1067 | static void free_gigantic_page(struct page *page, unsigned int order) |
944d9fec LC |
1068 | { |
1069 | free_contig_range(page_to_pfn(page), 1 << order); | |
1070 | } | |
1071 | ||
4eb0716e | 1072 | #ifdef CONFIG_CONTIG_ALLOC |
944d9fec | 1073 | static int __alloc_gigantic_page(unsigned long start_pfn, |
79b63f12 | 1074 | unsigned long nr_pages, gfp_t gfp_mask) |
944d9fec LC |
1075 | { |
1076 | unsigned long end_pfn = start_pfn + nr_pages; | |
ca96b625 | 1077 | return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE, |
79b63f12 | 1078 | gfp_mask); |
944d9fec LC |
1079 | } |
1080 | ||
f44b2dda JK |
1081 | static bool pfn_range_valid_gigantic(struct zone *z, |
1082 | unsigned long start_pfn, unsigned long nr_pages) | |
944d9fec LC |
1083 | { |
1084 | unsigned long i, end_pfn = start_pfn + nr_pages; | |
1085 | struct page *page; | |
1086 | ||
1087 | for (i = start_pfn; i < end_pfn; i++) { | |
f231fe42 DH |
1088 | page = pfn_to_online_page(i); |
1089 | if (!page) | |
944d9fec LC |
1090 | return false; |
1091 | ||
f44b2dda JK |
1092 | if (page_zone(page) != z) |
1093 | return false; | |
1094 | ||
944d9fec LC |
1095 | if (PageReserved(page)) |
1096 | return false; | |
1097 | ||
1098 | if (page_count(page) > 0) | |
1099 | return false; | |
1100 | ||
1101 | if (PageHuge(page)) | |
1102 | return false; | |
1103 | } | |
1104 | ||
1105 | return true; | |
1106 | } | |
1107 | ||
1108 | static bool zone_spans_last_pfn(const struct zone *zone, | |
1109 | unsigned long start_pfn, unsigned long nr_pages) | |
1110 | { | |
1111 | unsigned long last_pfn = start_pfn + nr_pages - 1; | |
1112 | return zone_spans_pfn(zone, last_pfn); | |
1113 | } | |
1114 | ||
d9cc948f MH |
1115 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, |
1116 | int nid, nodemask_t *nodemask) | |
944d9fec | 1117 | { |
79b63f12 | 1118 | unsigned int order = huge_page_order(h); |
944d9fec LC |
1119 | unsigned long nr_pages = 1 << order; |
1120 | unsigned long ret, pfn, flags; | |
79b63f12 MH |
1121 | struct zonelist *zonelist; |
1122 | struct zone *zone; | |
1123 | struct zoneref *z; | |
944d9fec | 1124 | |
79b63f12 | 1125 | zonelist = node_zonelist(nid, gfp_mask); |
d9cc948f | 1126 | for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nodemask) { |
79b63f12 | 1127 | spin_lock_irqsave(&zone->lock, flags); |
944d9fec | 1128 | |
79b63f12 MH |
1129 | pfn = ALIGN(zone->zone_start_pfn, nr_pages); |
1130 | while (zone_spans_last_pfn(zone, pfn, nr_pages)) { | |
1131 | if (pfn_range_valid_gigantic(zone, pfn, nr_pages)) { | |
944d9fec LC |
1132 | /* |
1133 | * We release the zone lock here because | |
1134 | * alloc_contig_range() will also lock the zone | |
1135 | * at some point. If there's an allocation | |
1136 | * spinning on this lock, it may win the race | |
1137 | * and cause alloc_contig_range() to fail... | |
1138 | */ | |
79b63f12 MH |
1139 | spin_unlock_irqrestore(&zone->lock, flags); |
1140 | ret = __alloc_gigantic_page(pfn, nr_pages, gfp_mask); | |
944d9fec LC |
1141 | if (!ret) |
1142 | return pfn_to_page(pfn); | |
79b63f12 | 1143 | spin_lock_irqsave(&zone->lock, flags); |
944d9fec LC |
1144 | } |
1145 | pfn += nr_pages; | |
1146 | } | |
1147 | ||
79b63f12 | 1148 | spin_unlock_irqrestore(&zone->lock, flags); |
944d9fec LC |
1149 | } |
1150 | ||
1151 | return NULL; | |
1152 | } | |
1153 | ||
1154 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); | |
d00181b9 | 1155 | static void prep_compound_gigantic_page(struct page *page, unsigned int order); |
4eb0716e AG |
1156 | #else /* !CONFIG_CONTIG_ALLOC */ |
1157 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, | |
1158 | int nid, nodemask_t *nodemask) | |
1159 | { | |
1160 | return NULL; | |
1161 | } | |
1162 | #endif /* CONFIG_CONTIG_ALLOC */ | |
944d9fec | 1163 | |
e1073d1e | 1164 | #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ |
d9cc948f | 1165 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, |
4eb0716e AG |
1166 | int nid, nodemask_t *nodemask) |
1167 | { | |
1168 | return NULL; | |
1169 | } | |
d00181b9 | 1170 | static inline void free_gigantic_page(struct page *page, unsigned int order) { } |
944d9fec | 1171 | static inline void destroy_compound_gigantic_page(struct page *page, |
d00181b9 | 1172 | unsigned int order) { } |
944d9fec LC |
1173 | #endif |
1174 | ||
a5516438 | 1175 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
1176 | { |
1177 | int i; | |
a5516438 | 1178 | |
4eb0716e | 1179 | if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) |
944d9fec | 1180 | return; |
18229df5 | 1181 | |
a5516438 AK |
1182 | h->nr_huge_pages--; |
1183 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
1184 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
32f84528 CF |
1185 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | |
1186 | 1 << PG_referenced | 1 << PG_dirty | | |
a7407a27 LC |
1187 | 1 << PG_active | 1 << PG_private | |
1188 | 1 << PG_writeback); | |
6af2acb6 | 1189 | } |
309381fe | 1190 | VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); |
f1e61557 | 1191 | set_compound_page_dtor(page, NULL_COMPOUND_DTOR); |
6af2acb6 | 1192 | set_page_refcounted(page); |
944d9fec LC |
1193 | if (hstate_is_gigantic(h)) { |
1194 | destroy_compound_gigantic_page(page, huge_page_order(h)); | |
1195 | free_gigantic_page(page, huge_page_order(h)); | |
1196 | } else { | |
944d9fec LC |
1197 | __free_pages(page, huge_page_order(h)); |
1198 | } | |
6af2acb6 AL |
1199 | } |
1200 | ||
e5ff2159 AK |
1201 | struct hstate *size_to_hstate(unsigned long size) |
1202 | { | |
1203 | struct hstate *h; | |
1204 | ||
1205 | for_each_hstate(h) { | |
1206 | if (huge_page_size(h) == size) | |
1207 | return h; | |
1208 | } | |
1209 | return NULL; | |
1210 | } | |
1211 | ||
bcc54222 NH |
1212 | /* |
1213 | * Test to determine whether the hugepage is "active/in-use" (i.e. being linked | |
1214 | * to hstate->hugepage_activelist.) | |
1215 | * | |
1216 | * This function can be called for tail pages, but never returns true for them. | |
1217 | */ | |
1218 | bool page_huge_active(struct page *page) | |
1219 | { | |
1220 | VM_BUG_ON_PAGE(!PageHuge(page), page); | |
1221 | return PageHead(page) && PagePrivate(&page[1]); | |
1222 | } | |
1223 | ||
1224 | /* never called for tail page */ | |
1225 | static void set_page_huge_active(struct page *page) | |
1226 | { | |
1227 | VM_BUG_ON_PAGE(!PageHeadHuge(page), page); | |
1228 | SetPagePrivate(&page[1]); | |
1229 | } | |
1230 | ||
1231 | static void clear_page_huge_active(struct page *page) | |
1232 | { | |
1233 | VM_BUG_ON_PAGE(!PageHeadHuge(page), page); | |
1234 | ClearPagePrivate(&page[1]); | |
1235 | } | |
1236 | ||
ab5ac90a MH |
1237 | /* |
1238 | * Internal hugetlb specific page flag. Do not use outside of the hugetlb | |
1239 | * code | |
1240 | */ | |
1241 | static inline bool PageHugeTemporary(struct page *page) | |
1242 | { | |
1243 | if (!PageHuge(page)) | |
1244 | return false; | |
1245 | ||
1246 | return (unsigned long)page[2].mapping == -1U; | |
1247 | } | |
1248 | ||
1249 | static inline void SetPageHugeTemporary(struct page *page) | |
1250 | { | |
1251 | page[2].mapping = (void *)-1U; | |
1252 | } | |
1253 | ||
1254 | static inline void ClearPageHugeTemporary(struct page *page) | |
1255 | { | |
1256 | page[2].mapping = NULL; | |
1257 | } | |
1258 | ||
ce44b015 | 1259 | static void __free_huge_page(struct page *page) |
27a85ef1 | 1260 | { |
a5516438 AK |
1261 | /* |
1262 | * Can't pass hstate in here because it is called from the | |
1263 | * compound page destructor. | |
1264 | */ | |
e5ff2159 | 1265 | struct hstate *h = page_hstate(page); |
7893d1d5 | 1266 | int nid = page_to_nid(page); |
90481622 DG |
1267 | struct hugepage_subpool *spool = |
1268 | (struct hugepage_subpool *)page_private(page); | |
07443a85 | 1269 | bool restore_reserve; |
27a85ef1 | 1270 | |
b4330afb MK |
1271 | VM_BUG_ON_PAGE(page_count(page), page); |
1272 | VM_BUG_ON_PAGE(page_mapcount(page), page); | |
8ace22bc YW |
1273 | |
1274 | set_page_private(page, 0); | |
1275 | page->mapping = NULL; | |
07443a85 | 1276 | restore_reserve = PagePrivate(page); |
16c794b4 | 1277 | ClearPagePrivate(page); |
27a85ef1 | 1278 | |
1c5ecae3 | 1279 | /* |
0919e1b6 MK |
1280 | * If PagePrivate() was set on page, page allocation consumed a |
1281 | * reservation. If the page was associated with a subpool, there | |
1282 | * would have been a page reserved in the subpool before allocation | |
1283 | * via hugepage_subpool_get_pages(). Since we are 'restoring' the | |
1284 | * reservtion, do not call hugepage_subpool_put_pages() as this will | |
1285 | * remove the reserved page from the subpool. | |
1c5ecae3 | 1286 | */ |
0919e1b6 MK |
1287 | if (!restore_reserve) { |
1288 | /* | |
1289 | * A return code of zero implies that the subpool will be | |
1290 | * under its minimum size if the reservation is not restored | |
1291 | * after page is free. Therefore, force restore_reserve | |
1292 | * operation. | |
1293 | */ | |
1294 | if (hugepage_subpool_put_pages(spool, 1) == 0) | |
1295 | restore_reserve = true; | |
1296 | } | |
1c5ecae3 | 1297 | |
27a85ef1 | 1298 | spin_lock(&hugetlb_lock); |
bcc54222 | 1299 | clear_page_huge_active(page); |
6d76dcf4 AK |
1300 | hugetlb_cgroup_uncharge_page(hstate_index(h), |
1301 | pages_per_huge_page(h), page); | |
07443a85 JK |
1302 | if (restore_reserve) |
1303 | h->resv_huge_pages++; | |
1304 | ||
ab5ac90a MH |
1305 | if (PageHugeTemporary(page)) { |
1306 | list_del(&page->lru); | |
1307 | ClearPageHugeTemporary(page); | |
1308 | update_and_free_page(h, page); | |
1309 | } else if (h->surplus_huge_pages_node[nid]) { | |
0edaecfa AK |
1310 | /* remove the page from active list */ |
1311 | list_del(&page->lru); | |
a5516438 AK |
1312 | update_and_free_page(h, page); |
1313 | h->surplus_huge_pages--; | |
1314 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 1315 | } else { |
5d3a551c | 1316 | arch_clear_hugepage_flags(page); |
a5516438 | 1317 | enqueue_huge_page(h, page); |
7893d1d5 | 1318 | } |
27a85ef1 DG |
1319 | spin_unlock(&hugetlb_lock); |
1320 | } | |
1321 | ||
ce44b015 WL |
1322 | /* |
1323 | * As free_huge_page() can be called from a non-task context, we have | |
1324 | * to defer the actual freeing in a workqueue to prevent potential | |
1325 | * hugetlb_lock deadlock. | |
1326 | * | |
1327 | * free_hpage_workfn() locklessly retrieves the linked list of pages to | |
1328 | * be freed and frees them one-by-one. As the page->mapping pointer is | |
1329 | * going to be cleared in __free_huge_page() anyway, it is reused as the | |
1330 | * llist_node structure of a lockless linked list of huge pages to be freed. | |
1331 | */ | |
1332 | static LLIST_HEAD(hpage_freelist); | |
1333 | ||
1334 | static void free_hpage_workfn(struct work_struct *work) | |
1335 | { | |
1336 | struct llist_node *node; | |
1337 | struct page *page; | |
1338 | ||
1339 | node = llist_del_all(&hpage_freelist); | |
1340 | ||
1341 | while (node) { | |
1342 | page = container_of((struct address_space **)node, | |
1343 | struct page, mapping); | |
1344 | node = node->next; | |
1345 | __free_huge_page(page); | |
1346 | } | |
1347 | } | |
1348 | static DECLARE_WORK(free_hpage_work, free_hpage_workfn); | |
1349 | ||
1350 | void free_huge_page(struct page *page) | |
1351 | { | |
1352 | /* | |
1353 | * Defer freeing if in non-task context to avoid hugetlb_lock deadlock. | |
1354 | */ | |
1355 | if (!in_task()) { | |
1356 | /* | |
1357 | * Only call schedule_work() if hpage_freelist is previously | |
1358 | * empty. Otherwise, schedule_work() had been called but the | |
1359 | * workfn hasn't retrieved the list yet. | |
1360 | */ | |
1361 | if (llist_add((struct llist_node *)&page->mapping, | |
1362 | &hpage_freelist)) | |
1363 | schedule_work(&free_hpage_work); | |
1364 | return; | |
1365 | } | |
1366 | ||
1367 | __free_huge_page(page); | |
1368 | } | |
1369 | ||
a5516438 | 1370 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 | 1371 | { |
0edaecfa | 1372 | INIT_LIST_HEAD(&page->lru); |
f1e61557 | 1373 | set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); |
b7ba30c6 | 1374 | spin_lock(&hugetlb_lock); |
9dd540e2 | 1375 | set_hugetlb_cgroup(page, NULL); |
a5516438 AK |
1376 | h->nr_huge_pages++; |
1377 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 | 1378 | spin_unlock(&hugetlb_lock); |
b7ba30c6 AK |
1379 | } |
1380 | ||
d00181b9 | 1381 | static void prep_compound_gigantic_page(struct page *page, unsigned int order) |
20a0307c WF |
1382 | { |
1383 | int i; | |
1384 | int nr_pages = 1 << order; | |
1385 | struct page *p = page + 1; | |
1386 | ||
1387 | /* we rely on prep_new_huge_page to set the destructor */ | |
1388 | set_compound_order(page, order); | |
ef5a22be | 1389 | __ClearPageReserved(page); |
de09d31d | 1390 | __SetPageHead(page); |
20a0307c | 1391 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
ef5a22be AA |
1392 | /* |
1393 | * For gigantic hugepages allocated through bootmem at | |
1394 | * boot, it's safer to be consistent with the not-gigantic | |
1395 | * hugepages and clear the PG_reserved bit from all tail pages | |
1396 | * too. Otherwse drivers using get_user_pages() to access tail | |
1397 | * pages may get the reference counting wrong if they see | |
1398 | * PG_reserved set on a tail page (despite the head page not | |
1399 | * having PG_reserved set). Enforcing this consistency between | |
1400 | * head and tail pages allows drivers to optimize away a check | |
1401 | * on the head page when they need know if put_page() is needed | |
1402 | * after get_user_pages(). | |
1403 | */ | |
1404 | __ClearPageReserved(p); | |
58a84aa9 | 1405 | set_page_count(p, 0); |
1d798ca3 | 1406 | set_compound_head(p, page); |
20a0307c | 1407 | } |
b4330afb | 1408 | atomic_set(compound_mapcount_ptr(page), -1); |
20a0307c WF |
1409 | } |
1410 | ||
7795912c AM |
1411 | /* |
1412 | * PageHuge() only returns true for hugetlbfs pages, but not for normal or | |
1413 | * transparent huge pages. See the PageTransHuge() documentation for more | |
1414 | * details. | |
1415 | */ | |
20a0307c WF |
1416 | int PageHuge(struct page *page) |
1417 | { | |
20a0307c WF |
1418 | if (!PageCompound(page)) |
1419 | return 0; | |
1420 | ||
1421 | page = compound_head(page); | |
f1e61557 | 1422 | return page[1].compound_dtor == HUGETLB_PAGE_DTOR; |
20a0307c | 1423 | } |
43131e14 NH |
1424 | EXPORT_SYMBOL_GPL(PageHuge); |
1425 | ||
27c73ae7 AA |
1426 | /* |
1427 | * PageHeadHuge() only returns true for hugetlbfs head page, but not for | |
1428 | * normal or transparent huge pages. | |
1429 | */ | |
1430 | int PageHeadHuge(struct page *page_head) | |
1431 | { | |
27c73ae7 AA |
1432 | if (!PageHead(page_head)) |
1433 | return 0; | |
1434 | ||
758f66a2 | 1435 | return get_compound_page_dtor(page_head) == free_huge_page; |
27c73ae7 | 1436 | } |
27c73ae7 | 1437 | |
13d60f4b ZY |
1438 | pgoff_t __basepage_index(struct page *page) |
1439 | { | |
1440 | struct page *page_head = compound_head(page); | |
1441 | pgoff_t index = page_index(page_head); | |
1442 | unsigned long compound_idx; | |
1443 | ||
1444 | if (!PageHuge(page_head)) | |
1445 | return page_index(page); | |
1446 | ||
1447 | if (compound_order(page_head) >= MAX_ORDER) | |
1448 | compound_idx = page_to_pfn(page) - page_to_pfn(page_head); | |
1449 | else | |
1450 | compound_idx = page - page_head; | |
1451 | ||
1452 | return (index << compound_order(page_head)) + compound_idx; | |
1453 | } | |
1454 | ||
0c397dae | 1455 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
f60858f9 MK |
1456 | gfp_t gfp_mask, int nid, nodemask_t *nmask, |
1457 | nodemask_t *node_alloc_noretry) | |
1da177e4 | 1458 | { |
af0fb9df | 1459 | int order = huge_page_order(h); |
1da177e4 | 1460 | struct page *page; |
f60858f9 | 1461 | bool alloc_try_hard = true; |
f96efd58 | 1462 | |
f60858f9 MK |
1463 | /* |
1464 | * By default we always try hard to allocate the page with | |
1465 | * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in | |
1466 | * a loop (to adjust global huge page counts) and previous allocation | |
1467 | * failed, do not continue to try hard on the same node. Use the | |
1468 | * node_alloc_noretry bitmap to manage this state information. | |
1469 | */ | |
1470 | if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) | |
1471 | alloc_try_hard = false; | |
1472 | gfp_mask |= __GFP_COMP|__GFP_NOWARN; | |
1473 | if (alloc_try_hard) | |
1474 | gfp_mask |= __GFP_RETRY_MAYFAIL; | |
af0fb9df MH |
1475 | if (nid == NUMA_NO_NODE) |
1476 | nid = numa_mem_id(); | |
1477 | page = __alloc_pages_nodemask(gfp_mask, order, nid, nmask); | |
1478 | if (page) | |
1479 | __count_vm_event(HTLB_BUDDY_PGALLOC); | |
1480 | else | |
1481 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
63b4613c | 1482 | |
f60858f9 MK |
1483 | /* |
1484 | * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this | |
1485 | * indicates an overall state change. Clear bit so that we resume | |
1486 | * normal 'try hard' allocations. | |
1487 | */ | |
1488 | if (node_alloc_noretry && page && !alloc_try_hard) | |
1489 | node_clear(nid, *node_alloc_noretry); | |
1490 | ||
1491 | /* | |
1492 | * If we tried hard to get a page but failed, set bit so that | |
1493 | * subsequent attempts will not try as hard until there is an | |
1494 | * overall state change. | |
1495 | */ | |
1496 | if (node_alloc_noretry && !page && alloc_try_hard) | |
1497 | node_set(nid, *node_alloc_noretry); | |
1498 | ||
63b4613c NA |
1499 | return page; |
1500 | } | |
1501 | ||
0c397dae MH |
1502 | /* |
1503 | * Common helper to allocate a fresh hugetlb page. All specific allocators | |
1504 | * should use this function to get new hugetlb pages | |
1505 | */ | |
1506 | static struct page *alloc_fresh_huge_page(struct hstate *h, | |
f60858f9 MK |
1507 | gfp_t gfp_mask, int nid, nodemask_t *nmask, |
1508 | nodemask_t *node_alloc_noretry) | |
0c397dae MH |
1509 | { |
1510 | struct page *page; | |
1511 | ||
1512 | if (hstate_is_gigantic(h)) | |
1513 | page = alloc_gigantic_page(h, gfp_mask, nid, nmask); | |
1514 | else | |
1515 | page = alloc_buddy_huge_page(h, gfp_mask, | |
f60858f9 | 1516 | nid, nmask, node_alloc_noretry); |
0c397dae MH |
1517 | if (!page) |
1518 | return NULL; | |
1519 | ||
1520 | if (hstate_is_gigantic(h)) | |
1521 | prep_compound_gigantic_page(page, huge_page_order(h)); | |
1522 | prep_new_huge_page(h, page, page_to_nid(page)); | |
1523 | ||
1524 | return page; | |
1525 | } | |
1526 | ||
af0fb9df MH |
1527 | /* |
1528 | * Allocates a fresh page to the hugetlb allocator pool in the node interleaved | |
1529 | * manner. | |
1530 | */ | |
f60858f9 MK |
1531 | static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
1532 | nodemask_t *node_alloc_noretry) | |
b2261026 JK |
1533 | { |
1534 | struct page *page; | |
1535 | int nr_nodes, node; | |
af0fb9df | 1536 | gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; |
b2261026 JK |
1537 | |
1538 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
f60858f9 MK |
1539 | page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, |
1540 | node_alloc_noretry); | |
af0fb9df | 1541 | if (page) |
b2261026 | 1542 | break; |
b2261026 JK |
1543 | } |
1544 | ||
af0fb9df MH |
1545 | if (!page) |
1546 | return 0; | |
b2261026 | 1547 | |
af0fb9df MH |
1548 | put_page(page); /* free it into the hugepage allocator */ |
1549 | ||
1550 | return 1; | |
b2261026 JK |
1551 | } |
1552 | ||
e8c5c824 LS |
1553 | /* |
1554 | * Free huge page from pool from next node to free. | |
1555 | * Attempt to keep persistent huge pages more or less | |
1556 | * balanced over allowed nodes. | |
1557 | * Called with hugetlb_lock locked. | |
1558 | */ | |
6ae11b27 LS |
1559 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
1560 | bool acct_surplus) | |
e8c5c824 | 1561 | { |
b2261026 | 1562 | int nr_nodes, node; |
e8c5c824 LS |
1563 | int ret = 0; |
1564 | ||
b2261026 | 1565 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { |
685f3457 LS |
1566 | /* |
1567 | * If we're returning unused surplus pages, only examine | |
1568 | * nodes with surplus pages. | |
1569 | */ | |
b2261026 JK |
1570 | if ((!acct_surplus || h->surplus_huge_pages_node[node]) && |
1571 | !list_empty(&h->hugepage_freelists[node])) { | |
e8c5c824 | 1572 | struct page *page = |
b2261026 | 1573 | list_entry(h->hugepage_freelists[node].next, |
e8c5c824 LS |
1574 | struct page, lru); |
1575 | list_del(&page->lru); | |
1576 | h->free_huge_pages--; | |
b2261026 | 1577 | h->free_huge_pages_node[node]--; |
685f3457 LS |
1578 | if (acct_surplus) { |
1579 | h->surplus_huge_pages--; | |
b2261026 | 1580 | h->surplus_huge_pages_node[node]--; |
685f3457 | 1581 | } |
e8c5c824 LS |
1582 | update_and_free_page(h, page); |
1583 | ret = 1; | |
9a76db09 | 1584 | break; |
e8c5c824 | 1585 | } |
b2261026 | 1586 | } |
e8c5c824 LS |
1587 | |
1588 | return ret; | |
1589 | } | |
1590 | ||
c8721bbb NH |
1591 | /* |
1592 | * Dissolve a given free hugepage into free buddy pages. This function does | |
faf53def NH |
1593 | * nothing for in-use hugepages and non-hugepages. |
1594 | * This function returns values like below: | |
1595 | * | |
1596 | * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use | |
1597 | * (allocated or reserved.) | |
1598 | * 0: successfully dissolved free hugepages or the page is not a | |
1599 | * hugepage (considered as already dissolved) | |
c8721bbb | 1600 | */ |
c3114a84 | 1601 | int dissolve_free_huge_page(struct page *page) |
c8721bbb | 1602 | { |
6bc9b564 | 1603 | int rc = -EBUSY; |
082d5b6b | 1604 | |
faf53def NH |
1605 | /* Not to disrupt normal path by vainly holding hugetlb_lock */ |
1606 | if (!PageHuge(page)) | |
1607 | return 0; | |
1608 | ||
c8721bbb | 1609 | spin_lock(&hugetlb_lock); |
faf53def NH |
1610 | if (!PageHuge(page)) { |
1611 | rc = 0; | |
1612 | goto out; | |
1613 | } | |
1614 | ||
1615 | if (!page_count(page)) { | |
2247bb33 GS |
1616 | struct page *head = compound_head(page); |
1617 | struct hstate *h = page_hstate(head); | |
1618 | int nid = page_to_nid(head); | |
6bc9b564 | 1619 | if (h->free_huge_pages - h->resv_huge_pages == 0) |
082d5b6b | 1620 | goto out; |
c3114a84 AK |
1621 | /* |
1622 | * Move PageHWPoison flag from head page to the raw error page, | |
1623 | * which makes any subpages rather than the error page reusable. | |
1624 | */ | |
1625 | if (PageHWPoison(head) && page != head) { | |
1626 | SetPageHWPoison(page); | |
1627 | ClearPageHWPoison(head); | |
1628 | } | |
2247bb33 | 1629 | list_del(&head->lru); |
c8721bbb NH |
1630 | h->free_huge_pages--; |
1631 | h->free_huge_pages_node[nid]--; | |
c1470b33 | 1632 | h->max_huge_pages--; |
2247bb33 | 1633 | update_and_free_page(h, head); |
6bc9b564 | 1634 | rc = 0; |
c8721bbb | 1635 | } |
082d5b6b | 1636 | out: |
c8721bbb | 1637 | spin_unlock(&hugetlb_lock); |
082d5b6b | 1638 | return rc; |
c8721bbb NH |
1639 | } |
1640 | ||
1641 | /* | |
1642 | * Dissolve free hugepages in a given pfn range. Used by memory hotplug to | |
1643 | * make specified memory blocks removable from the system. | |
2247bb33 GS |
1644 | * Note that this will dissolve a free gigantic hugepage completely, if any |
1645 | * part of it lies within the given range. | |
082d5b6b GS |
1646 | * Also note that if dissolve_free_huge_page() returns with an error, all |
1647 | * free hugepages that were dissolved before that error are lost. | |
c8721bbb | 1648 | */ |
082d5b6b | 1649 | int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) |
c8721bbb | 1650 | { |
c8721bbb | 1651 | unsigned long pfn; |
eb03aa00 | 1652 | struct page *page; |
082d5b6b | 1653 | int rc = 0; |
c8721bbb | 1654 | |
d0177639 | 1655 | if (!hugepages_supported()) |
082d5b6b | 1656 | return rc; |
d0177639 | 1657 | |
eb03aa00 GS |
1658 | for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { |
1659 | page = pfn_to_page(pfn); | |
faf53def NH |
1660 | rc = dissolve_free_huge_page(page); |
1661 | if (rc) | |
1662 | break; | |
eb03aa00 | 1663 | } |
082d5b6b GS |
1664 | |
1665 | return rc; | |
c8721bbb NH |
1666 | } |
1667 | ||
ab5ac90a MH |
1668 | /* |
1669 | * Allocates a fresh surplus page from the page allocator. | |
1670 | */ | |
0c397dae | 1671 | static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, |
aaf14e40 | 1672 | int nid, nodemask_t *nmask) |
7893d1d5 | 1673 | { |
9980d744 | 1674 | struct page *page = NULL; |
7893d1d5 | 1675 | |
bae7f4ae | 1676 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
1677 | return NULL; |
1678 | ||
d1c3fb1f | 1679 | spin_lock(&hugetlb_lock); |
9980d744 MH |
1680 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) |
1681 | goto out_unlock; | |
d1c3fb1f NA |
1682 | spin_unlock(&hugetlb_lock); |
1683 | ||
f60858f9 | 1684 | page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); |
9980d744 | 1685 | if (!page) |
0c397dae | 1686 | return NULL; |
d1c3fb1f NA |
1687 | |
1688 | spin_lock(&hugetlb_lock); | |
9980d744 MH |
1689 | /* |
1690 | * We could have raced with the pool size change. | |
1691 | * Double check that and simply deallocate the new page | |
1692 | * if we would end up overcommiting the surpluses. Abuse | |
1693 | * temporary page to workaround the nasty free_huge_page | |
1694 | * codeflow | |
1695 | */ | |
1696 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { | |
1697 | SetPageHugeTemporary(page); | |
2bf753e6 | 1698 | spin_unlock(&hugetlb_lock); |
9980d744 | 1699 | put_page(page); |
2bf753e6 | 1700 | return NULL; |
9980d744 | 1701 | } else { |
9980d744 | 1702 | h->surplus_huge_pages++; |
4704dea3 | 1703 | h->surplus_huge_pages_node[page_to_nid(page)]++; |
7893d1d5 | 1704 | } |
9980d744 MH |
1705 | |
1706 | out_unlock: | |
d1c3fb1f | 1707 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
1708 | |
1709 | return page; | |
1710 | } | |
1711 | ||
9a4e9f3b AK |
1712 | struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, |
1713 | int nid, nodemask_t *nmask) | |
ab5ac90a MH |
1714 | { |
1715 | struct page *page; | |
1716 | ||
1717 | if (hstate_is_gigantic(h)) | |
1718 | return NULL; | |
1719 | ||
f60858f9 | 1720 | page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); |
ab5ac90a MH |
1721 | if (!page) |
1722 | return NULL; | |
1723 | ||
1724 | /* | |
1725 | * We do not account these pages as surplus because they are only | |
1726 | * temporary and will be released properly on the last reference | |
1727 | */ | |
ab5ac90a MH |
1728 | SetPageHugeTemporary(page); |
1729 | ||
1730 | return page; | |
1731 | } | |
1732 | ||
099730d6 DH |
1733 | /* |
1734 | * Use the VMA's mpolicy to allocate a huge page from the buddy. | |
1735 | */ | |
e0ec90ee | 1736 | static |
0c397dae | 1737 | struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, |
099730d6 DH |
1738 | struct vm_area_struct *vma, unsigned long addr) |
1739 | { | |
aaf14e40 MH |
1740 | struct page *page; |
1741 | struct mempolicy *mpol; | |
1742 | gfp_t gfp_mask = htlb_alloc_mask(h); | |
1743 | int nid; | |
1744 | nodemask_t *nodemask; | |
1745 | ||
1746 | nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); | |
0c397dae | 1747 | page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); |
aaf14e40 MH |
1748 | mpol_cond_put(mpol); |
1749 | ||
1750 | return page; | |
099730d6 DH |
1751 | } |
1752 | ||
ab5ac90a | 1753 | /* page migration callback function */ |
bf50bab2 NH |
1754 | struct page *alloc_huge_page_node(struct hstate *h, int nid) |
1755 | { | |
aaf14e40 | 1756 | gfp_t gfp_mask = htlb_alloc_mask(h); |
4ef91848 | 1757 | struct page *page = NULL; |
bf50bab2 | 1758 | |
aaf14e40 MH |
1759 | if (nid != NUMA_NO_NODE) |
1760 | gfp_mask |= __GFP_THISNODE; | |
1761 | ||
bf50bab2 | 1762 | spin_lock(&hugetlb_lock); |
4ef91848 | 1763 | if (h->free_huge_pages - h->resv_huge_pages > 0) |
3e59fcb0 | 1764 | page = dequeue_huge_page_nodemask(h, gfp_mask, nid, NULL); |
bf50bab2 NH |
1765 | spin_unlock(&hugetlb_lock); |
1766 | ||
94ae8ba7 | 1767 | if (!page) |
0c397dae | 1768 | page = alloc_migrate_huge_page(h, gfp_mask, nid, NULL); |
bf50bab2 NH |
1769 | |
1770 | return page; | |
1771 | } | |
1772 | ||
ab5ac90a | 1773 | /* page migration callback function */ |
3e59fcb0 MH |
1774 | struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, |
1775 | nodemask_t *nmask) | |
4db9b2ef | 1776 | { |
aaf14e40 | 1777 | gfp_t gfp_mask = htlb_alloc_mask(h); |
4db9b2ef MH |
1778 | |
1779 | spin_lock(&hugetlb_lock); | |
1780 | if (h->free_huge_pages - h->resv_huge_pages > 0) { | |
3e59fcb0 MH |
1781 | struct page *page; |
1782 | ||
1783 | page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); | |
1784 | if (page) { | |
1785 | spin_unlock(&hugetlb_lock); | |
1786 | return page; | |
4db9b2ef MH |
1787 | } |
1788 | } | |
1789 | spin_unlock(&hugetlb_lock); | |
4db9b2ef | 1790 | |
0c397dae | 1791 | return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); |
4db9b2ef MH |
1792 | } |
1793 | ||
ebd63723 | 1794 | /* mempolicy aware migration callback */ |
389c8178 MH |
1795 | struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, |
1796 | unsigned long address) | |
ebd63723 MH |
1797 | { |
1798 | struct mempolicy *mpol; | |
1799 | nodemask_t *nodemask; | |
1800 | struct page *page; | |
ebd63723 MH |
1801 | gfp_t gfp_mask; |
1802 | int node; | |
1803 | ||
ebd63723 MH |
1804 | gfp_mask = htlb_alloc_mask(h); |
1805 | node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); | |
1806 | page = alloc_huge_page_nodemask(h, node, nodemask); | |
1807 | mpol_cond_put(mpol); | |
1808 | ||
1809 | return page; | |
1810 | } | |
1811 | ||
e4e574b7 | 1812 | /* |
25985edc | 1813 | * Increase the hugetlb pool such that it can accommodate a reservation |
e4e574b7 AL |
1814 | * of size 'delta'. |
1815 | */ | |
a5516438 | 1816 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
1817 | { |
1818 | struct list_head surplus_list; | |
1819 | struct page *page, *tmp; | |
1820 | int ret, i; | |
1821 | int needed, allocated; | |
28073b02 | 1822 | bool alloc_ok = true; |
e4e574b7 | 1823 | |
a5516438 | 1824 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 1825 | if (needed <= 0) { |
a5516438 | 1826 | h->resv_huge_pages += delta; |
e4e574b7 | 1827 | return 0; |
ac09b3a1 | 1828 | } |
e4e574b7 AL |
1829 | |
1830 | allocated = 0; | |
1831 | INIT_LIST_HEAD(&surplus_list); | |
1832 | ||
1833 | ret = -ENOMEM; | |
1834 | retry: | |
1835 | spin_unlock(&hugetlb_lock); | |
1836 | for (i = 0; i < needed; i++) { | |
0c397dae | 1837 | page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), |
aaf14e40 | 1838 | NUMA_NO_NODE, NULL); |
28073b02 HD |
1839 | if (!page) { |
1840 | alloc_ok = false; | |
1841 | break; | |
1842 | } | |
e4e574b7 | 1843 | list_add(&page->lru, &surplus_list); |
69ed779a | 1844 | cond_resched(); |
e4e574b7 | 1845 | } |
28073b02 | 1846 | allocated += i; |
e4e574b7 AL |
1847 | |
1848 | /* | |
1849 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
1850 | * because either resv_huge_pages or free_huge_pages may have changed. | |
1851 | */ | |
1852 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
1853 | needed = (h->resv_huge_pages + delta) - |
1854 | (h->free_huge_pages + allocated); | |
28073b02 HD |
1855 | if (needed > 0) { |
1856 | if (alloc_ok) | |
1857 | goto retry; | |
1858 | /* | |
1859 | * We were not able to allocate enough pages to | |
1860 | * satisfy the entire reservation so we free what | |
1861 | * we've allocated so far. | |
1862 | */ | |
1863 | goto free; | |
1864 | } | |
e4e574b7 AL |
1865 | /* |
1866 | * The surplus_list now contains _at_least_ the number of extra pages | |
25985edc | 1867 | * needed to accommodate the reservation. Add the appropriate number |
e4e574b7 | 1868 | * of pages to the hugetlb pool and free the extras back to the buddy |
ac09b3a1 AL |
1869 | * allocator. Commit the entire reservation here to prevent another |
1870 | * process from stealing the pages as they are added to the pool but | |
1871 | * before they are reserved. | |
e4e574b7 AL |
1872 | */ |
1873 | needed += allocated; | |
a5516438 | 1874 | h->resv_huge_pages += delta; |
e4e574b7 | 1875 | ret = 0; |
a9869b83 | 1876 | |
19fc3f0a | 1877 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 1878 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
1879 | if ((--needed) < 0) |
1880 | break; | |
a9869b83 NH |
1881 | /* |
1882 | * This page is now managed by the hugetlb allocator and has | |
1883 | * no users -- drop the buddy allocator's reference. | |
1884 | */ | |
1885 | put_page_testzero(page); | |
309381fe | 1886 | VM_BUG_ON_PAGE(page_count(page), page); |
a5516438 | 1887 | enqueue_huge_page(h, page); |
19fc3f0a | 1888 | } |
28073b02 | 1889 | free: |
b0365c8d | 1890 | spin_unlock(&hugetlb_lock); |
19fc3f0a AL |
1891 | |
1892 | /* Free unnecessary surplus pages to the buddy allocator */ | |
c0d934ba JK |
1893 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) |
1894 | put_page(page); | |
a9869b83 | 1895 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
1896 | |
1897 | return ret; | |
1898 | } | |
1899 | ||
1900 | /* | |
e5bbc8a6 MK |
1901 | * This routine has two main purposes: |
1902 | * 1) Decrement the reservation count (resv_huge_pages) by the value passed | |
1903 | * in unused_resv_pages. This corresponds to the prior adjustments made | |
1904 | * to the associated reservation map. | |
1905 | * 2) Free any unused surplus pages that may have been allocated to satisfy | |
1906 | * the reservation. As many as unused_resv_pages may be freed. | |
1907 | * | |
1908 | * Called with hugetlb_lock held. However, the lock could be dropped (and | |
1909 | * reacquired) during calls to cond_resched_lock. Whenever dropping the lock, | |
1910 | * we must make sure nobody else can claim pages we are in the process of | |
1911 | * freeing. Do this by ensuring resv_huge_page always is greater than the | |
1912 | * number of huge pages we plan to free when dropping the lock. | |
e4e574b7 | 1913 | */ |
a5516438 AK |
1914 | static void return_unused_surplus_pages(struct hstate *h, |
1915 | unsigned long unused_resv_pages) | |
e4e574b7 | 1916 | { |
e4e574b7 AL |
1917 | unsigned long nr_pages; |
1918 | ||
aa888a74 | 1919 | /* Cannot return gigantic pages currently */ |
bae7f4ae | 1920 | if (hstate_is_gigantic(h)) |
e5bbc8a6 | 1921 | goto out; |
aa888a74 | 1922 | |
e5bbc8a6 MK |
1923 | /* |
1924 | * Part (or even all) of the reservation could have been backed | |
1925 | * by pre-allocated pages. Only free surplus pages. | |
1926 | */ | |
a5516438 | 1927 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 1928 | |
685f3457 LS |
1929 | /* |
1930 | * We want to release as many surplus pages as possible, spread | |
9b5e5d0f LS |
1931 | * evenly across all nodes with memory. Iterate across these nodes |
1932 | * until we can no longer free unreserved surplus pages. This occurs | |
1933 | * when the nodes with surplus pages have no free pages. | |
1934 | * free_pool_huge_page() will balance the the freed pages across the | |
1935 | * on-line nodes with memory and will handle the hstate accounting. | |
e5bbc8a6 MK |
1936 | * |
1937 | * Note that we decrement resv_huge_pages as we free the pages. If | |
1938 | * we drop the lock, resv_huge_pages will still be sufficiently large | |
1939 | * to cover subsequent pages we may free. | |
685f3457 LS |
1940 | */ |
1941 | while (nr_pages--) { | |
e5bbc8a6 MK |
1942 | h->resv_huge_pages--; |
1943 | unused_resv_pages--; | |
8cebfcd0 | 1944 | if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) |
e5bbc8a6 | 1945 | goto out; |
7848a4bf | 1946 | cond_resched_lock(&hugetlb_lock); |
e4e574b7 | 1947 | } |
e5bbc8a6 MK |
1948 | |
1949 | out: | |
1950 | /* Fully uncommit the reservation */ | |
1951 | h->resv_huge_pages -= unused_resv_pages; | |
e4e574b7 AL |
1952 | } |
1953 | ||
5e911373 | 1954 | |
c37f9fb1 | 1955 | /* |
feba16e2 | 1956 | * vma_needs_reservation, vma_commit_reservation and vma_end_reservation |
5e911373 | 1957 | * are used by the huge page allocation routines to manage reservations. |
cf3ad20b MK |
1958 | * |
1959 | * vma_needs_reservation is called to determine if the huge page at addr | |
1960 | * within the vma has an associated reservation. If a reservation is | |
1961 | * needed, the value 1 is returned. The caller is then responsible for | |
1962 | * managing the global reservation and subpool usage counts. After | |
1963 | * the huge page has been allocated, vma_commit_reservation is called | |
feba16e2 MK |
1964 | * to add the page to the reservation map. If the page allocation fails, |
1965 | * the reservation must be ended instead of committed. vma_end_reservation | |
1966 | * is called in such cases. | |
cf3ad20b MK |
1967 | * |
1968 | * In the normal case, vma_commit_reservation returns the same value | |
1969 | * as the preceding vma_needs_reservation call. The only time this | |
1970 | * is not the case is if a reserve map was changed between calls. It | |
1971 | * is the responsibility of the caller to notice the difference and | |
1972 | * take appropriate action. | |
96b96a96 MK |
1973 | * |
1974 | * vma_add_reservation is used in error paths where a reservation must | |
1975 | * be restored when a newly allocated huge page must be freed. It is | |
1976 | * to be called after calling vma_needs_reservation to determine if a | |
1977 | * reservation exists. | |
c37f9fb1 | 1978 | */ |
5e911373 MK |
1979 | enum vma_resv_mode { |
1980 | VMA_NEEDS_RESV, | |
1981 | VMA_COMMIT_RESV, | |
feba16e2 | 1982 | VMA_END_RESV, |
96b96a96 | 1983 | VMA_ADD_RESV, |
5e911373 | 1984 | }; |
cf3ad20b MK |
1985 | static long __vma_reservation_common(struct hstate *h, |
1986 | struct vm_area_struct *vma, unsigned long addr, | |
5e911373 | 1987 | enum vma_resv_mode mode) |
c37f9fb1 | 1988 | { |
4e35f483 JK |
1989 | struct resv_map *resv; |
1990 | pgoff_t idx; | |
cf3ad20b | 1991 | long ret; |
c37f9fb1 | 1992 | |
4e35f483 JK |
1993 | resv = vma_resv_map(vma); |
1994 | if (!resv) | |
84afd99b | 1995 | return 1; |
c37f9fb1 | 1996 | |
4e35f483 | 1997 | idx = vma_hugecache_offset(h, vma, addr); |
5e911373 MK |
1998 | switch (mode) { |
1999 | case VMA_NEEDS_RESV: | |
cf3ad20b | 2000 | ret = region_chg(resv, idx, idx + 1); |
5e911373 MK |
2001 | break; |
2002 | case VMA_COMMIT_RESV: | |
2003 | ret = region_add(resv, idx, idx + 1); | |
2004 | break; | |
feba16e2 | 2005 | case VMA_END_RESV: |
5e911373 MK |
2006 | region_abort(resv, idx, idx + 1); |
2007 | ret = 0; | |
2008 | break; | |
96b96a96 MK |
2009 | case VMA_ADD_RESV: |
2010 | if (vma->vm_flags & VM_MAYSHARE) | |
2011 | ret = region_add(resv, idx, idx + 1); | |
2012 | else { | |
2013 | region_abort(resv, idx, idx + 1); | |
2014 | ret = region_del(resv, idx, idx + 1); | |
2015 | } | |
2016 | break; | |
5e911373 MK |
2017 | default: |
2018 | BUG(); | |
2019 | } | |
84afd99b | 2020 | |
4e35f483 | 2021 | if (vma->vm_flags & VM_MAYSHARE) |
cf3ad20b | 2022 | return ret; |
67961f9d MK |
2023 | else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) { |
2024 | /* | |
2025 | * In most cases, reserves always exist for private mappings. | |
2026 | * However, a file associated with mapping could have been | |
2027 | * hole punched or truncated after reserves were consumed. | |
2028 | * As subsequent fault on such a range will not use reserves. | |
2029 | * Subtle - The reserve map for private mappings has the | |
2030 | * opposite meaning than that of shared mappings. If NO | |
2031 | * entry is in the reserve map, it means a reservation exists. | |
2032 | * If an entry exists in the reserve map, it means the | |
2033 | * reservation has already been consumed. As a result, the | |
2034 | * return value of this routine is the opposite of the | |
2035 | * value returned from reserve map manipulation routines above. | |
2036 | */ | |
2037 | if (ret) | |
2038 | return 0; | |
2039 | else | |
2040 | return 1; | |
2041 | } | |
4e35f483 | 2042 | else |
cf3ad20b | 2043 | return ret < 0 ? ret : 0; |
c37f9fb1 | 2044 | } |
cf3ad20b MK |
2045 | |
2046 | static long vma_needs_reservation(struct hstate *h, | |
a5516438 | 2047 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 | 2048 | { |
5e911373 | 2049 | return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); |
cf3ad20b | 2050 | } |
84afd99b | 2051 | |
cf3ad20b MK |
2052 | static long vma_commit_reservation(struct hstate *h, |
2053 | struct vm_area_struct *vma, unsigned long addr) | |
2054 | { | |
5e911373 MK |
2055 | return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); |
2056 | } | |
2057 | ||
feba16e2 | 2058 | static void vma_end_reservation(struct hstate *h, |
5e911373 MK |
2059 | struct vm_area_struct *vma, unsigned long addr) |
2060 | { | |
feba16e2 | 2061 | (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); |
c37f9fb1 AW |
2062 | } |
2063 | ||
96b96a96 MK |
2064 | static long vma_add_reservation(struct hstate *h, |
2065 | struct vm_area_struct *vma, unsigned long addr) | |
2066 | { | |
2067 | return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); | |
2068 | } | |
2069 | ||
2070 | /* | |
2071 | * This routine is called to restore a reservation on error paths. In the | |
2072 | * specific error paths, a huge page was allocated (via alloc_huge_page) | |
2073 | * and is about to be freed. If a reservation for the page existed, | |
2074 | * alloc_huge_page would have consumed the reservation and set PagePrivate | |
2075 | * in the newly allocated page. When the page is freed via free_huge_page, | |
2076 | * the global reservation count will be incremented if PagePrivate is set. | |
2077 | * However, free_huge_page can not adjust the reserve map. Adjust the | |
2078 | * reserve map here to be consistent with global reserve count adjustments | |
2079 | * to be made by free_huge_page. | |
2080 | */ | |
2081 | static void restore_reserve_on_error(struct hstate *h, | |
2082 | struct vm_area_struct *vma, unsigned long address, | |
2083 | struct page *page) | |
2084 | { | |
2085 | if (unlikely(PagePrivate(page))) { | |
2086 | long rc = vma_needs_reservation(h, vma, address); | |
2087 | ||
2088 | if (unlikely(rc < 0)) { | |
2089 | /* | |
2090 | * Rare out of memory condition in reserve map | |
2091 | * manipulation. Clear PagePrivate so that | |
2092 | * global reserve count will not be incremented | |
2093 | * by free_huge_page. This will make it appear | |
2094 | * as though the reservation for this page was | |
2095 | * consumed. This may prevent the task from | |
2096 | * faulting in the page at a later time. This | |
2097 | * is better than inconsistent global huge page | |
2098 | * accounting of reserve counts. | |
2099 | */ | |
2100 | ClearPagePrivate(page); | |
2101 | } else if (rc) { | |
2102 | rc = vma_add_reservation(h, vma, address); | |
2103 | if (unlikely(rc < 0)) | |
2104 | /* | |
2105 | * See above comment about rare out of | |
2106 | * memory condition. | |
2107 | */ | |
2108 | ClearPagePrivate(page); | |
2109 | } else | |
2110 | vma_end_reservation(h, vma, address); | |
2111 | } | |
2112 | } | |
2113 | ||
70c3547e | 2114 | struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 2115 | unsigned long addr, int avoid_reserve) |
1da177e4 | 2116 | { |
90481622 | 2117 | struct hugepage_subpool *spool = subpool_vma(vma); |
a5516438 | 2118 | struct hstate *h = hstate_vma(vma); |
348ea204 | 2119 | struct page *page; |
d85f69b0 MK |
2120 | long map_chg, map_commit; |
2121 | long gbl_chg; | |
6d76dcf4 AK |
2122 | int ret, idx; |
2123 | struct hugetlb_cgroup *h_cg; | |
a1e78772 | 2124 | |
6d76dcf4 | 2125 | idx = hstate_index(h); |
a1e78772 | 2126 | /* |
d85f69b0 MK |
2127 | * Examine the region/reserve map to determine if the process |
2128 | * has a reservation for the page to be allocated. A return | |
2129 | * code of zero indicates a reservation exists (no change). | |
a1e78772 | 2130 | */ |
d85f69b0 MK |
2131 | map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); |
2132 | if (map_chg < 0) | |
76dcee75 | 2133 | return ERR_PTR(-ENOMEM); |
d85f69b0 MK |
2134 | |
2135 | /* | |
2136 | * Processes that did not create the mapping will have no | |
2137 | * reserves as indicated by the region/reserve map. Check | |
2138 | * that the allocation will not exceed the subpool limit. | |
2139 | * Allocations for MAP_NORESERVE mappings also need to be | |
2140 | * checked against any subpool limit. | |
2141 | */ | |
2142 | if (map_chg || avoid_reserve) { | |
2143 | gbl_chg = hugepage_subpool_get_pages(spool, 1); | |
2144 | if (gbl_chg < 0) { | |
feba16e2 | 2145 | vma_end_reservation(h, vma, addr); |
76dcee75 | 2146 | return ERR_PTR(-ENOSPC); |
5e911373 | 2147 | } |
1da177e4 | 2148 | |
d85f69b0 MK |
2149 | /* |
2150 | * Even though there was no reservation in the region/reserve | |
2151 | * map, there could be reservations associated with the | |
2152 | * subpool that can be used. This would be indicated if the | |
2153 | * return value of hugepage_subpool_get_pages() is zero. | |
2154 | * However, if avoid_reserve is specified we still avoid even | |
2155 | * the subpool reservations. | |
2156 | */ | |
2157 | if (avoid_reserve) | |
2158 | gbl_chg = 1; | |
2159 | } | |
2160 | ||
6d76dcf4 | 2161 | ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); |
8f34af6f JZ |
2162 | if (ret) |
2163 | goto out_subpool_put; | |
2164 | ||
1da177e4 | 2165 | spin_lock(&hugetlb_lock); |
d85f69b0 MK |
2166 | /* |
2167 | * glb_chg is passed to indicate whether or not a page must be taken | |
2168 | * from the global free pool (global change). gbl_chg == 0 indicates | |
2169 | * a reservation exists for the allocation. | |
2170 | */ | |
2171 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); | |
81a6fcae | 2172 | if (!page) { |
94ae8ba7 | 2173 | spin_unlock(&hugetlb_lock); |
0c397dae | 2174 | page = alloc_buddy_huge_page_with_mpol(h, vma, addr); |
8f34af6f JZ |
2175 | if (!page) |
2176 | goto out_uncharge_cgroup; | |
a88c7695 NH |
2177 | if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { |
2178 | SetPagePrivate(page); | |
2179 | h->resv_huge_pages--; | |
2180 | } | |
79dbb236 AK |
2181 | spin_lock(&hugetlb_lock); |
2182 | list_move(&page->lru, &h->hugepage_activelist); | |
81a6fcae | 2183 | /* Fall through */ |
68842c9b | 2184 | } |
81a6fcae JK |
2185 | hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); |
2186 | spin_unlock(&hugetlb_lock); | |
348ea204 | 2187 | |
90481622 | 2188 | set_page_private(page, (unsigned long)spool); |
90d8b7e6 | 2189 | |
d85f69b0 MK |
2190 | map_commit = vma_commit_reservation(h, vma, addr); |
2191 | if (unlikely(map_chg > map_commit)) { | |
33039678 MK |
2192 | /* |
2193 | * The page was added to the reservation map between | |
2194 | * vma_needs_reservation and vma_commit_reservation. | |
2195 | * This indicates a race with hugetlb_reserve_pages. | |
2196 | * Adjust for the subpool count incremented above AND | |
2197 | * in hugetlb_reserve_pages for the same page. Also, | |
2198 | * the reservation count added in hugetlb_reserve_pages | |
2199 | * no longer applies. | |
2200 | */ | |
2201 | long rsv_adjust; | |
2202 | ||
2203 | rsv_adjust = hugepage_subpool_put_pages(spool, 1); | |
2204 | hugetlb_acct_memory(h, -rsv_adjust); | |
2205 | } | |
90d8b7e6 | 2206 | return page; |
8f34af6f JZ |
2207 | |
2208 | out_uncharge_cgroup: | |
2209 | hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); | |
2210 | out_subpool_put: | |
d85f69b0 | 2211 | if (map_chg || avoid_reserve) |
8f34af6f | 2212 | hugepage_subpool_put_pages(spool, 1); |
feba16e2 | 2213 | vma_end_reservation(h, vma, addr); |
8f34af6f | 2214 | return ERR_PTR(-ENOSPC); |
b45b5bd6 DG |
2215 | } |
2216 | ||
e24a1307 AK |
2217 | int alloc_bootmem_huge_page(struct hstate *h) |
2218 | __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); | |
2219 | int __alloc_bootmem_huge_page(struct hstate *h) | |
aa888a74 AK |
2220 | { |
2221 | struct huge_bootmem_page *m; | |
b2261026 | 2222 | int nr_nodes, node; |
aa888a74 | 2223 | |
b2261026 | 2224 | for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { |
aa888a74 AK |
2225 | void *addr; |
2226 | ||
eb31d559 | 2227 | addr = memblock_alloc_try_nid_raw( |
8b89a116 | 2228 | huge_page_size(h), huge_page_size(h), |
97ad1087 | 2229 | 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); |
aa888a74 AK |
2230 | if (addr) { |
2231 | /* | |
2232 | * Use the beginning of the huge page to store the | |
2233 | * huge_bootmem_page struct (until gather_bootmem | |
2234 | * puts them into the mem_map). | |
2235 | */ | |
2236 | m = addr; | |
91f47662 | 2237 | goto found; |
aa888a74 | 2238 | } |
aa888a74 AK |
2239 | } |
2240 | return 0; | |
2241 | ||
2242 | found: | |
df994ead | 2243 | BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); |
aa888a74 | 2244 | /* Put them into a private list first because mem_map is not up yet */ |
330d6e48 | 2245 | INIT_LIST_HEAD(&m->list); |
aa888a74 AK |
2246 | list_add(&m->list, &huge_boot_pages); |
2247 | m->hstate = h; | |
2248 | return 1; | |
2249 | } | |
2250 | ||
d00181b9 KS |
2251 | static void __init prep_compound_huge_page(struct page *page, |
2252 | unsigned int order) | |
18229df5 AW |
2253 | { |
2254 | if (unlikely(order > (MAX_ORDER - 1))) | |
2255 | prep_compound_gigantic_page(page, order); | |
2256 | else | |
2257 | prep_compound_page(page, order); | |
2258 | } | |
2259 | ||
aa888a74 AK |
2260 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
2261 | static void __init gather_bootmem_prealloc(void) | |
2262 | { | |
2263 | struct huge_bootmem_page *m; | |
2264 | ||
2265 | list_for_each_entry(m, &huge_boot_pages, list) { | |
40d18ebf | 2266 | struct page *page = virt_to_page(m); |
aa888a74 | 2267 | struct hstate *h = m->hstate; |
ee8f248d | 2268 | |
aa888a74 | 2269 | WARN_ON(page_count(page) != 1); |
18229df5 | 2270 | prep_compound_huge_page(page, h->order); |
ef5a22be | 2271 | WARN_ON(PageReserved(page)); |
aa888a74 | 2272 | prep_new_huge_page(h, page, page_to_nid(page)); |
af0fb9df MH |
2273 | put_page(page); /* free it into the hugepage allocator */ |
2274 | ||
b0320c7b RA |
2275 | /* |
2276 | * If we had gigantic hugepages allocated at boot time, we need | |
2277 | * to restore the 'stolen' pages to totalram_pages in order to | |
2278 | * fix confusing memory reports from free(1) and another | |
2279 | * side-effects, like CommitLimit going negative. | |
2280 | */ | |
bae7f4ae | 2281 | if (hstate_is_gigantic(h)) |
3dcc0571 | 2282 | adjust_managed_page_count(page, 1 << h->order); |
520495fe | 2283 | cond_resched(); |
aa888a74 AK |
2284 | } |
2285 | } | |
2286 | ||
8faa8b07 | 2287 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
2288 | { |
2289 | unsigned long i; | |
f60858f9 MK |
2290 | nodemask_t *node_alloc_noretry; |
2291 | ||
2292 | if (!hstate_is_gigantic(h)) { | |
2293 | /* | |
2294 | * Bit mask controlling how hard we retry per-node allocations. | |
2295 | * Ignore errors as lower level routines can deal with | |
2296 | * node_alloc_noretry == NULL. If this kmalloc fails at boot | |
2297 | * time, we are likely in bigger trouble. | |
2298 | */ | |
2299 | node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), | |
2300 | GFP_KERNEL); | |
2301 | } else { | |
2302 | /* allocations done at boot time */ | |
2303 | node_alloc_noretry = NULL; | |
2304 | } | |
2305 | ||
2306 | /* bit mask controlling how hard we retry per-node allocations */ | |
2307 | if (node_alloc_noretry) | |
2308 | nodes_clear(*node_alloc_noretry); | |
a5516438 | 2309 | |
e5ff2159 | 2310 | for (i = 0; i < h->max_huge_pages; ++i) { |
bae7f4ae | 2311 | if (hstate_is_gigantic(h)) { |
aa888a74 AK |
2312 | if (!alloc_bootmem_huge_page(h)) |
2313 | break; | |
0c397dae | 2314 | } else if (!alloc_pool_huge_page(h, |
f60858f9 MK |
2315 | &node_states[N_MEMORY], |
2316 | node_alloc_noretry)) | |
1da177e4 | 2317 | break; |
69ed779a | 2318 | cond_resched(); |
1da177e4 | 2319 | } |
d715cf80 LH |
2320 | if (i < h->max_huge_pages) { |
2321 | char buf[32]; | |
2322 | ||
c6247f72 | 2323 | string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); |
d715cf80 LH |
2324 | pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", |
2325 | h->max_huge_pages, buf, i); | |
2326 | h->max_huge_pages = i; | |
2327 | } | |
f60858f9 MK |
2328 | |
2329 | kfree(node_alloc_noretry); | |
e5ff2159 AK |
2330 | } |
2331 | ||
2332 | static void __init hugetlb_init_hstates(void) | |
2333 | { | |
2334 | struct hstate *h; | |
2335 | ||
2336 | for_each_hstate(h) { | |
641844f5 NH |
2337 | if (minimum_order > huge_page_order(h)) |
2338 | minimum_order = huge_page_order(h); | |
2339 | ||
8faa8b07 | 2340 | /* oversize hugepages were init'ed in early boot */ |
bae7f4ae | 2341 | if (!hstate_is_gigantic(h)) |
8faa8b07 | 2342 | hugetlb_hstate_alloc_pages(h); |
e5ff2159 | 2343 | } |
641844f5 | 2344 | VM_BUG_ON(minimum_order == UINT_MAX); |
e5ff2159 AK |
2345 | } |
2346 | ||
2347 | static void __init report_hugepages(void) | |
2348 | { | |
2349 | struct hstate *h; | |
2350 | ||
2351 | for_each_hstate(h) { | |
4abd32db | 2352 | char buf[32]; |
c6247f72 MW |
2353 | |
2354 | string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); | |
ffb22af5 | 2355 | pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", |
c6247f72 | 2356 | buf, h->free_huge_pages); |
e5ff2159 AK |
2357 | } |
2358 | } | |
2359 | ||
1da177e4 | 2360 | #ifdef CONFIG_HIGHMEM |
6ae11b27 LS |
2361 | static void try_to_free_low(struct hstate *h, unsigned long count, |
2362 | nodemask_t *nodes_allowed) | |
1da177e4 | 2363 | { |
4415cc8d CL |
2364 | int i; |
2365 | ||
bae7f4ae | 2366 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
2367 | return; |
2368 | ||
6ae11b27 | 2369 | for_each_node_mask(i, *nodes_allowed) { |
1da177e4 | 2370 | struct page *page, *next; |
a5516438 AK |
2371 | struct list_head *freel = &h->hugepage_freelists[i]; |
2372 | list_for_each_entry_safe(page, next, freel, lru) { | |
2373 | if (count >= h->nr_huge_pages) | |
6b0c880d | 2374 | return; |
1da177e4 LT |
2375 | if (PageHighMem(page)) |
2376 | continue; | |
2377 | list_del(&page->lru); | |
e5ff2159 | 2378 | update_and_free_page(h, page); |
a5516438 AK |
2379 | h->free_huge_pages--; |
2380 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
2381 | } |
2382 | } | |
2383 | } | |
2384 | #else | |
6ae11b27 LS |
2385 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
2386 | nodemask_t *nodes_allowed) | |
1da177e4 LT |
2387 | { |
2388 | } | |
2389 | #endif | |
2390 | ||
20a0307c WF |
2391 | /* |
2392 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
2393 | * balanced by operating on them in a round-robin fashion. | |
2394 | * Returns 1 if an adjustment was made. | |
2395 | */ | |
6ae11b27 LS |
2396 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
2397 | int delta) | |
20a0307c | 2398 | { |
b2261026 | 2399 | int nr_nodes, node; |
20a0307c WF |
2400 | |
2401 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 2402 | |
b2261026 JK |
2403 | if (delta < 0) { |
2404 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
2405 | if (h->surplus_huge_pages_node[node]) | |
2406 | goto found; | |
e8c5c824 | 2407 | } |
b2261026 JK |
2408 | } else { |
2409 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | |
2410 | if (h->surplus_huge_pages_node[node] < | |
2411 | h->nr_huge_pages_node[node]) | |
2412 | goto found; | |
e8c5c824 | 2413 | } |
b2261026 JK |
2414 | } |
2415 | return 0; | |
20a0307c | 2416 | |
b2261026 JK |
2417 | found: |
2418 | h->surplus_huge_pages += delta; | |
2419 | h->surplus_huge_pages_node[node] += delta; | |
2420 | return 1; | |
20a0307c WF |
2421 | } |
2422 | ||
a5516438 | 2423 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
fd875dca | 2424 | static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, |
4eb0716e | 2425 | nodemask_t *nodes_allowed) |
1da177e4 | 2426 | { |
7893d1d5 | 2427 | unsigned long min_count, ret; |
f60858f9 MK |
2428 | NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); |
2429 | ||
2430 | /* | |
2431 | * Bit mask controlling how hard we retry per-node allocations. | |
2432 | * If we can not allocate the bit mask, do not attempt to allocate | |
2433 | * the requested huge pages. | |
2434 | */ | |
2435 | if (node_alloc_noretry) | |
2436 | nodes_clear(*node_alloc_noretry); | |
2437 | else | |
2438 | return -ENOMEM; | |
1da177e4 | 2439 | |
4eb0716e AG |
2440 | spin_lock(&hugetlb_lock); |
2441 | ||
fd875dca MK |
2442 | /* |
2443 | * Check for a node specific request. | |
2444 | * Changing node specific huge page count may require a corresponding | |
2445 | * change to the global count. In any case, the passed node mask | |
2446 | * (nodes_allowed) will restrict alloc/free to the specified node. | |
2447 | */ | |
2448 | if (nid != NUMA_NO_NODE) { | |
2449 | unsigned long old_count = count; | |
2450 | ||
2451 | count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; | |
2452 | /* | |
2453 | * User may have specified a large count value which caused the | |
2454 | * above calculation to overflow. In this case, they wanted | |
2455 | * to allocate as many huge pages as possible. Set count to | |
2456 | * largest possible value to align with their intention. | |
2457 | */ | |
2458 | if (count < old_count) | |
2459 | count = ULONG_MAX; | |
2460 | } | |
2461 | ||
4eb0716e AG |
2462 | /* |
2463 | * Gigantic pages runtime allocation depend on the capability for large | |
2464 | * page range allocation. | |
2465 | * If the system does not provide this feature, return an error when | |
2466 | * the user tries to allocate gigantic pages but let the user free the | |
2467 | * boottime allocated gigantic pages. | |
2468 | */ | |
2469 | if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { | |
2470 | if (count > persistent_huge_pages(h)) { | |
2471 | spin_unlock(&hugetlb_lock); | |
f60858f9 | 2472 | NODEMASK_FREE(node_alloc_noretry); |
4eb0716e AG |
2473 | return -EINVAL; |
2474 | } | |
2475 | /* Fall through to decrease pool */ | |
2476 | } | |
aa888a74 | 2477 | |
7893d1d5 AL |
2478 | /* |
2479 | * Increase the pool size | |
2480 | * First take pages out of surplus state. Then make up the | |
2481 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f | 2482 | * |
0c397dae | 2483 | * We might race with alloc_surplus_huge_page() here and be unable |
d1c3fb1f NA |
2484 | * to convert a surplus huge page to a normal huge page. That is |
2485 | * not critical, though, it just means the overall size of the | |
2486 | * pool might be one hugepage larger than it needs to be, but | |
2487 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 2488 | */ |
a5516438 | 2489 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
6ae11b27 | 2490 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
7893d1d5 AL |
2491 | break; |
2492 | } | |
2493 | ||
a5516438 | 2494 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
2495 | /* |
2496 | * If this allocation races such that we no longer need the | |
2497 | * page, free_huge_page will handle it by freeing the page | |
2498 | * and reducing the surplus. | |
2499 | */ | |
2500 | spin_unlock(&hugetlb_lock); | |
649920c6 JH |
2501 | |
2502 | /* yield cpu to avoid soft lockup */ | |
2503 | cond_resched(); | |
2504 | ||
f60858f9 MK |
2505 | ret = alloc_pool_huge_page(h, nodes_allowed, |
2506 | node_alloc_noretry); | |
7893d1d5 AL |
2507 | spin_lock(&hugetlb_lock); |
2508 | if (!ret) | |
2509 | goto out; | |
2510 | ||
536240f2 MG |
2511 | /* Bail for signals. Probably ctrl-c from user */ |
2512 | if (signal_pending(current)) | |
2513 | goto out; | |
7893d1d5 | 2514 | } |
7893d1d5 AL |
2515 | |
2516 | /* | |
2517 | * Decrease the pool size | |
2518 | * First return free pages to the buddy allocator (being careful | |
2519 | * to keep enough around to satisfy reservations). Then place | |
2520 | * pages into surplus state as needed so the pool will shrink | |
2521 | * to the desired size as pages become free. | |
d1c3fb1f NA |
2522 | * |
2523 | * By placing pages into the surplus state independent of the | |
2524 | * overcommit value, we are allowing the surplus pool size to | |
2525 | * exceed overcommit. There are few sane options here. Since | |
0c397dae | 2526 | * alloc_surplus_huge_page() is checking the global counter, |
d1c3fb1f NA |
2527 | * though, we'll note that we're not allowed to exceed surplus |
2528 | * and won't grow the pool anywhere else. Not until one of the | |
2529 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 2530 | */ |
a5516438 | 2531 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 2532 | min_count = max(count, min_count); |
6ae11b27 | 2533 | try_to_free_low(h, min_count, nodes_allowed); |
a5516438 | 2534 | while (min_count < persistent_huge_pages(h)) { |
6ae11b27 | 2535 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1da177e4 | 2536 | break; |
55f67141 | 2537 | cond_resched_lock(&hugetlb_lock); |
1da177e4 | 2538 | } |
a5516438 | 2539 | while (count < persistent_huge_pages(h)) { |
6ae11b27 | 2540 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
7893d1d5 AL |
2541 | break; |
2542 | } | |
2543 | out: | |
4eb0716e | 2544 | h->max_huge_pages = persistent_huge_pages(h); |
1da177e4 | 2545 | spin_unlock(&hugetlb_lock); |
4eb0716e | 2546 | |
f60858f9 MK |
2547 | NODEMASK_FREE(node_alloc_noretry); |
2548 | ||
4eb0716e | 2549 | return 0; |
1da177e4 LT |
2550 | } |
2551 | ||
a3437870 NA |
2552 | #define HSTATE_ATTR_RO(_name) \ |
2553 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
2554 | ||
2555 | #define HSTATE_ATTR(_name) \ | |
2556 | static struct kobj_attribute _name##_attr = \ | |
2557 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
2558 | ||
2559 | static struct kobject *hugepages_kobj; | |
2560 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
2561 | ||
9a305230 LS |
2562 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); |
2563 | ||
2564 | static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) | |
a3437870 NA |
2565 | { |
2566 | int i; | |
9a305230 | 2567 | |
a3437870 | 2568 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
9a305230 LS |
2569 | if (hstate_kobjs[i] == kobj) { |
2570 | if (nidp) | |
2571 | *nidp = NUMA_NO_NODE; | |
a3437870 | 2572 | return &hstates[i]; |
9a305230 LS |
2573 | } |
2574 | ||
2575 | return kobj_to_node_hstate(kobj, nidp); | |
a3437870 NA |
2576 | } |
2577 | ||
06808b08 | 2578 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
a3437870 NA |
2579 | struct kobj_attribute *attr, char *buf) |
2580 | { | |
9a305230 LS |
2581 | struct hstate *h; |
2582 | unsigned long nr_huge_pages; | |
2583 | int nid; | |
2584 | ||
2585 | h = kobj_to_hstate(kobj, &nid); | |
2586 | if (nid == NUMA_NO_NODE) | |
2587 | nr_huge_pages = h->nr_huge_pages; | |
2588 | else | |
2589 | nr_huge_pages = h->nr_huge_pages_node[nid]; | |
2590 | ||
2591 | return sprintf(buf, "%lu\n", nr_huge_pages); | |
a3437870 | 2592 | } |
adbe8726 | 2593 | |
238d3c13 DR |
2594 | static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, |
2595 | struct hstate *h, int nid, | |
2596 | unsigned long count, size_t len) | |
a3437870 NA |
2597 | { |
2598 | int err; | |
2d0adf7e | 2599 | nodemask_t nodes_allowed, *n_mask; |
a3437870 | 2600 | |
2d0adf7e OS |
2601 | if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) |
2602 | return -EINVAL; | |
adbe8726 | 2603 | |
9a305230 LS |
2604 | if (nid == NUMA_NO_NODE) { |
2605 | /* | |
2606 | * global hstate attribute | |
2607 | */ | |
2608 | if (!(obey_mempolicy && | |
2d0adf7e OS |
2609 | init_nodemask_of_mempolicy(&nodes_allowed))) |
2610 | n_mask = &node_states[N_MEMORY]; | |
2611 | else | |
2612 | n_mask = &nodes_allowed; | |
2613 | } else { | |
9a305230 | 2614 | /* |
fd875dca MK |
2615 | * Node specific request. count adjustment happens in |
2616 | * set_max_huge_pages() after acquiring hugetlb_lock. | |
9a305230 | 2617 | */ |
2d0adf7e OS |
2618 | init_nodemask_of_node(&nodes_allowed, nid); |
2619 | n_mask = &nodes_allowed; | |
fd875dca | 2620 | } |
9a305230 | 2621 | |
2d0adf7e | 2622 | err = set_max_huge_pages(h, count, nid, n_mask); |
06808b08 | 2623 | |
4eb0716e | 2624 | return err ? err : len; |
06808b08 LS |
2625 | } |
2626 | ||
238d3c13 DR |
2627 | static ssize_t nr_hugepages_store_common(bool obey_mempolicy, |
2628 | struct kobject *kobj, const char *buf, | |
2629 | size_t len) | |
2630 | { | |
2631 | struct hstate *h; | |
2632 | unsigned long count; | |
2633 | int nid; | |
2634 | int err; | |
2635 | ||
2636 | err = kstrtoul(buf, 10, &count); | |
2637 | if (err) | |
2638 | return err; | |
2639 | ||
2640 | h = kobj_to_hstate(kobj, &nid); | |
2641 | return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); | |
2642 | } | |
2643 | ||
06808b08 LS |
2644 | static ssize_t nr_hugepages_show(struct kobject *kobj, |
2645 | struct kobj_attribute *attr, char *buf) | |
2646 | { | |
2647 | return nr_hugepages_show_common(kobj, attr, buf); | |
2648 | } | |
2649 | ||
2650 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
2651 | struct kobj_attribute *attr, const char *buf, size_t len) | |
2652 | { | |
238d3c13 | 2653 | return nr_hugepages_store_common(false, kobj, buf, len); |
a3437870 NA |
2654 | } |
2655 | HSTATE_ATTR(nr_hugepages); | |
2656 | ||
06808b08 LS |
2657 | #ifdef CONFIG_NUMA |
2658 | ||
2659 | /* | |
2660 | * hstate attribute for optionally mempolicy-based constraint on persistent | |
2661 | * huge page alloc/free. | |
2662 | */ | |
2663 | static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, | |
2664 | struct kobj_attribute *attr, char *buf) | |
2665 | { | |
2666 | return nr_hugepages_show_common(kobj, attr, buf); | |
2667 | } | |
2668 | ||
2669 | static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, | |
2670 | struct kobj_attribute *attr, const char *buf, size_t len) | |
2671 | { | |
238d3c13 | 2672 | return nr_hugepages_store_common(true, kobj, buf, len); |
06808b08 LS |
2673 | } |
2674 | HSTATE_ATTR(nr_hugepages_mempolicy); | |
2675 | #endif | |
2676 | ||
2677 | ||
a3437870 NA |
2678 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
2679 | struct kobj_attribute *attr, char *buf) | |
2680 | { | |
9a305230 | 2681 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
2682 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); |
2683 | } | |
adbe8726 | 2684 | |
a3437870 NA |
2685 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, |
2686 | struct kobj_attribute *attr, const char *buf, size_t count) | |
2687 | { | |
2688 | int err; | |
2689 | unsigned long input; | |
9a305230 | 2690 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 | 2691 | |
bae7f4ae | 2692 | if (hstate_is_gigantic(h)) |
adbe8726 EM |
2693 | return -EINVAL; |
2694 | ||
3dbb95f7 | 2695 | err = kstrtoul(buf, 10, &input); |
a3437870 | 2696 | if (err) |
73ae31e5 | 2697 | return err; |
a3437870 NA |
2698 | |
2699 | spin_lock(&hugetlb_lock); | |
2700 | h->nr_overcommit_huge_pages = input; | |
2701 | spin_unlock(&hugetlb_lock); | |
2702 | ||
2703 | return count; | |
2704 | } | |
2705 | HSTATE_ATTR(nr_overcommit_hugepages); | |
2706 | ||
2707 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
2708 | struct kobj_attribute *attr, char *buf) | |
2709 | { | |
9a305230 LS |
2710 | struct hstate *h; |
2711 | unsigned long free_huge_pages; | |
2712 | int nid; | |
2713 | ||
2714 | h = kobj_to_hstate(kobj, &nid); | |
2715 | if (nid == NUMA_NO_NODE) | |
2716 | free_huge_pages = h->free_huge_pages; | |
2717 | else | |
2718 | free_huge_pages = h->free_huge_pages_node[nid]; | |
2719 | ||
2720 | return sprintf(buf, "%lu\n", free_huge_pages); | |
a3437870 NA |
2721 | } |
2722 | HSTATE_ATTR_RO(free_hugepages); | |
2723 | ||
2724 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
2725 | struct kobj_attribute *attr, char *buf) | |
2726 | { | |
9a305230 | 2727 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
2728 | return sprintf(buf, "%lu\n", h->resv_huge_pages); |
2729 | } | |
2730 | HSTATE_ATTR_RO(resv_hugepages); | |
2731 | ||
2732 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
2733 | struct kobj_attribute *attr, char *buf) | |
2734 | { | |
9a305230 LS |
2735 | struct hstate *h; |
2736 | unsigned long surplus_huge_pages; | |
2737 | int nid; | |
2738 | ||
2739 | h = kobj_to_hstate(kobj, &nid); | |
2740 | if (nid == NUMA_NO_NODE) | |
2741 | surplus_huge_pages = h->surplus_huge_pages; | |
2742 | else | |
2743 | surplus_huge_pages = h->surplus_huge_pages_node[nid]; | |
2744 | ||
2745 | return sprintf(buf, "%lu\n", surplus_huge_pages); | |
a3437870 NA |
2746 | } |
2747 | HSTATE_ATTR_RO(surplus_hugepages); | |
2748 | ||
2749 | static struct attribute *hstate_attrs[] = { | |
2750 | &nr_hugepages_attr.attr, | |
2751 | &nr_overcommit_hugepages_attr.attr, | |
2752 | &free_hugepages_attr.attr, | |
2753 | &resv_hugepages_attr.attr, | |
2754 | &surplus_hugepages_attr.attr, | |
06808b08 LS |
2755 | #ifdef CONFIG_NUMA |
2756 | &nr_hugepages_mempolicy_attr.attr, | |
2757 | #endif | |
a3437870 NA |
2758 | NULL, |
2759 | }; | |
2760 | ||
67e5ed96 | 2761 | static const struct attribute_group hstate_attr_group = { |
a3437870 NA |
2762 | .attrs = hstate_attrs, |
2763 | }; | |
2764 | ||
094e9539 JM |
2765 | static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, |
2766 | struct kobject **hstate_kobjs, | |
67e5ed96 | 2767 | const struct attribute_group *hstate_attr_group) |
a3437870 NA |
2768 | { |
2769 | int retval; | |
972dc4de | 2770 | int hi = hstate_index(h); |
a3437870 | 2771 | |
9a305230 LS |
2772 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
2773 | if (!hstate_kobjs[hi]) | |
a3437870 NA |
2774 | return -ENOMEM; |
2775 | ||
9a305230 | 2776 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
a3437870 | 2777 | if (retval) |
9a305230 | 2778 | kobject_put(hstate_kobjs[hi]); |
a3437870 NA |
2779 | |
2780 | return retval; | |
2781 | } | |
2782 | ||
2783 | static void __init hugetlb_sysfs_init(void) | |
2784 | { | |
2785 | struct hstate *h; | |
2786 | int err; | |
2787 | ||
2788 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
2789 | if (!hugepages_kobj) | |
2790 | return; | |
2791 | ||
2792 | for_each_hstate(h) { | |
9a305230 LS |
2793 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
2794 | hstate_kobjs, &hstate_attr_group); | |
a3437870 | 2795 | if (err) |
ffb22af5 | 2796 | pr_err("Hugetlb: Unable to add hstate %s", h->name); |
a3437870 NA |
2797 | } |
2798 | } | |
2799 | ||
9a305230 LS |
2800 | #ifdef CONFIG_NUMA |
2801 | ||
2802 | /* | |
2803 | * node_hstate/s - associate per node hstate attributes, via their kobjects, | |
10fbcf4c KS |
2804 | * with node devices in node_devices[] using a parallel array. The array |
2805 | * index of a node device or _hstate == node id. | |
2806 | * This is here to avoid any static dependency of the node device driver, in | |
9a305230 LS |
2807 | * the base kernel, on the hugetlb module. |
2808 | */ | |
2809 | struct node_hstate { | |
2810 | struct kobject *hugepages_kobj; | |
2811 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
2812 | }; | |
b4e289a6 | 2813 | static struct node_hstate node_hstates[MAX_NUMNODES]; |
9a305230 LS |
2814 | |
2815 | /* | |
10fbcf4c | 2816 | * A subset of global hstate attributes for node devices |
9a305230 LS |
2817 | */ |
2818 | static struct attribute *per_node_hstate_attrs[] = { | |
2819 | &nr_hugepages_attr.attr, | |
2820 | &free_hugepages_attr.attr, | |
2821 | &surplus_hugepages_attr.attr, | |
2822 | NULL, | |
2823 | }; | |
2824 | ||
67e5ed96 | 2825 | static const struct attribute_group per_node_hstate_attr_group = { |
9a305230 LS |
2826 | .attrs = per_node_hstate_attrs, |
2827 | }; | |
2828 | ||
2829 | /* | |
10fbcf4c | 2830 | * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. |
9a305230 LS |
2831 | * Returns node id via non-NULL nidp. |
2832 | */ | |
2833 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
2834 | { | |
2835 | int nid; | |
2836 | ||
2837 | for (nid = 0; nid < nr_node_ids; nid++) { | |
2838 | struct node_hstate *nhs = &node_hstates[nid]; | |
2839 | int i; | |
2840 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
2841 | if (nhs->hstate_kobjs[i] == kobj) { | |
2842 | if (nidp) | |
2843 | *nidp = nid; | |
2844 | return &hstates[i]; | |
2845 | } | |
2846 | } | |
2847 | ||
2848 | BUG(); | |
2849 | return NULL; | |
2850 | } | |
2851 | ||
2852 | /* | |
10fbcf4c | 2853 | * Unregister hstate attributes from a single node device. |
9a305230 LS |
2854 | * No-op if no hstate attributes attached. |
2855 | */ | |
3cd8b44f | 2856 | static void hugetlb_unregister_node(struct node *node) |
9a305230 LS |
2857 | { |
2858 | struct hstate *h; | |
10fbcf4c | 2859 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2860 | |
2861 | if (!nhs->hugepages_kobj) | |
9b5e5d0f | 2862 | return; /* no hstate attributes */ |
9a305230 | 2863 | |
972dc4de AK |
2864 | for_each_hstate(h) { |
2865 | int idx = hstate_index(h); | |
2866 | if (nhs->hstate_kobjs[idx]) { | |
2867 | kobject_put(nhs->hstate_kobjs[idx]); | |
2868 | nhs->hstate_kobjs[idx] = NULL; | |
9a305230 | 2869 | } |
972dc4de | 2870 | } |
9a305230 LS |
2871 | |
2872 | kobject_put(nhs->hugepages_kobj); | |
2873 | nhs->hugepages_kobj = NULL; | |
2874 | } | |
2875 | ||
9a305230 LS |
2876 | |
2877 | /* | |
10fbcf4c | 2878 | * Register hstate attributes for a single node device. |
9a305230 LS |
2879 | * No-op if attributes already registered. |
2880 | */ | |
3cd8b44f | 2881 | static void hugetlb_register_node(struct node *node) |
9a305230 LS |
2882 | { |
2883 | struct hstate *h; | |
10fbcf4c | 2884 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2885 | int err; |
2886 | ||
2887 | if (nhs->hugepages_kobj) | |
2888 | return; /* already allocated */ | |
2889 | ||
2890 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", | |
10fbcf4c | 2891 | &node->dev.kobj); |
9a305230 LS |
2892 | if (!nhs->hugepages_kobj) |
2893 | return; | |
2894 | ||
2895 | for_each_hstate(h) { | |
2896 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, | |
2897 | nhs->hstate_kobjs, | |
2898 | &per_node_hstate_attr_group); | |
2899 | if (err) { | |
ffb22af5 AM |
2900 | pr_err("Hugetlb: Unable to add hstate %s for node %d\n", |
2901 | h->name, node->dev.id); | |
9a305230 LS |
2902 | hugetlb_unregister_node(node); |
2903 | break; | |
2904 | } | |
2905 | } | |
2906 | } | |
2907 | ||
2908 | /* | |
9b5e5d0f | 2909 | * hugetlb init time: register hstate attributes for all registered node |
10fbcf4c KS |
2910 | * devices of nodes that have memory. All on-line nodes should have |
2911 | * registered their associated device by this time. | |
9a305230 | 2912 | */ |
7d9ca000 | 2913 | static void __init hugetlb_register_all_nodes(void) |
9a305230 LS |
2914 | { |
2915 | int nid; | |
2916 | ||
8cebfcd0 | 2917 | for_each_node_state(nid, N_MEMORY) { |
8732794b | 2918 | struct node *node = node_devices[nid]; |
10fbcf4c | 2919 | if (node->dev.id == nid) |
9a305230 LS |
2920 | hugetlb_register_node(node); |
2921 | } | |
2922 | ||
2923 | /* | |
10fbcf4c | 2924 | * Let the node device driver know we're here so it can |
9a305230 LS |
2925 | * [un]register hstate attributes on node hotplug. |
2926 | */ | |
2927 | register_hugetlbfs_with_node(hugetlb_register_node, | |
2928 | hugetlb_unregister_node); | |
2929 | } | |
2930 | #else /* !CONFIG_NUMA */ | |
2931 | ||
2932 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
2933 | { | |
2934 | BUG(); | |
2935 | if (nidp) | |
2936 | *nidp = -1; | |
2937 | return NULL; | |
2938 | } | |
2939 | ||
9a305230 LS |
2940 | static void hugetlb_register_all_nodes(void) { } |
2941 | ||
2942 | #endif | |
2943 | ||
a3437870 NA |
2944 | static int __init hugetlb_init(void) |
2945 | { | |
8382d914 DB |
2946 | int i; |
2947 | ||
457c1b27 | 2948 | if (!hugepages_supported()) |
0ef89d25 | 2949 | return 0; |
a3437870 | 2950 | |
e11bfbfc | 2951 | if (!size_to_hstate(default_hstate_size)) { |
d715cf80 LH |
2952 | if (default_hstate_size != 0) { |
2953 | pr_err("HugeTLB: unsupported default_hugepagesz %lu. Reverting to %lu\n", | |
2954 | default_hstate_size, HPAGE_SIZE); | |
2955 | } | |
2956 | ||
e11bfbfc NP |
2957 | default_hstate_size = HPAGE_SIZE; |
2958 | if (!size_to_hstate(default_hstate_size)) | |
2959 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 2960 | } |
972dc4de | 2961 | default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size)); |
f8b74815 VT |
2962 | if (default_hstate_max_huge_pages) { |
2963 | if (!default_hstate.max_huge_pages) | |
2964 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
2965 | } | |
a3437870 NA |
2966 | |
2967 | hugetlb_init_hstates(); | |
aa888a74 | 2968 | gather_bootmem_prealloc(); |
a3437870 NA |
2969 | report_hugepages(); |
2970 | ||
2971 | hugetlb_sysfs_init(); | |
9a305230 | 2972 | hugetlb_register_all_nodes(); |
7179e7bf | 2973 | hugetlb_cgroup_file_init(); |
9a305230 | 2974 | |
8382d914 DB |
2975 | #ifdef CONFIG_SMP |
2976 | num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); | |
2977 | #else | |
2978 | num_fault_mutexes = 1; | |
2979 | #endif | |
c672c7f2 | 2980 | hugetlb_fault_mutex_table = |
6da2ec56 KC |
2981 | kmalloc_array(num_fault_mutexes, sizeof(struct mutex), |
2982 | GFP_KERNEL); | |
c672c7f2 | 2983 | BUG_ON(!hugetlb_fault_mutex_table); |
8382d914 DB |
2984 | |
2985 | for (i = 0; i < num_fault_mutexes; i++) | |
c672c7f2 | 2986 | mutex_init(&hugetlb_fault_mutex_table[i]); |
a3437870 NA |
2987 | return 0; |
2988 | } | |
3e89e1c5 | 2989 | subsys_initcall(hugetlb_init); |
a3437870 NA |
2990 | |
2991 | /* Should be called on processing a hugepagesz=... option */ | |
9fee021d VT |
2992 | void __init hugetlb_bad_size(void) |
2993 | { | |
2994 | parsed_valid_hugepagesz = false; | |
2995 | } | |
2996 | ||
d00181b9 | 2997 | void __init hugetlb_add_hstate(unsigned int order) |
a3437870 NA |
2998 | { |
2999 | struct hstate *h; | |
8faa8b07 AK |
3000 | unsigned long i; |
3001 | ||
a3437870 | 3002 | if (size_to_hstate(PAGE_SIZE << order)) { |
598d8091 | 3003 | pr_warn("hugepagesz= specified twice, ignoring\n"); |
a3437870 NA |
3004 | return; |
3005 | } | |
47d38344 | 3006 | BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); |
a3437870 | 3007 | BUG_ON(order == 0); |
47d38344 | 3008 | h = &hstates[hugetlb_max_hstate++]; |
a3437870 NA |
3009 | h->order = order; |
3010 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
3011 | h->nr_huge_pages = 0; |
3012 | h->free_huge_pages = 0; | |
3013 | for (i = 0; i < MAX_NUMNODES; ++i) | |
3014 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
0edaecfa | 3015 | INIT_LIST_HEAD(&h->hugepage_activelist); |
54f18d35 AM |
3016 | h->next_nid_to_alloc = first_memory_node; |
3017 | h->next_nid_to_free = first_memory_node; | |
a3437870 NA |
3018 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
3019 | huge_page_size(h)/1024); | |
8faa8b07 | 3020 | |
a3437870 NA |
3021 | parsed_hstate = h; |
3022 | } | |
3023 | ||
e11bfbfc | 3024 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
3025 | { |
3026 | unsigned long *mhp; | |
8faa8b07 | 3027 | static unsigned long *last_mhp; |
a3437870 | 3028 | |
9fee021d VT |
3029 | if (!parsed_valid_hugepagesz) { |
3030 | pr_warn("hugepages = %s preceded by " | |
3031 | "an unsupported hugepagesz, ignoring\n", s); | |
3032 | parsed_valid_hugepagesz = true; | |
3033 | return 1; | |
3034 | } | |
a3437870 | 3035 | /* |
47d38344 | 3036 | * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet, |
a3437870 NA |
3037 | * so this hugepages= parameter goes to the "default hstate". |
3038 | */ | |
9fee021d | 3039 | else if (!hugetlb_max_hstate) |
a3437870 NA |
3040 | mhp = &default_hstate_max_huge_pages; |
3041 | else | |
3042 | mhp = &parsed_hstate->max_huge_pages; | |
3043 | ||
8faa8b07 | 3044 | if (mhp == last_mhp) { |
598d8091 | 3045 | pr_warn("hugepages= specified twice without interleaving hugepagesz=, ignoring\n"); |
8faa8b07 AK |
3046 | return 1; |
3047 | } | |
3048 | ||
a3437870 NA |
3049 | if (sscanf(s, "%lu", mhp) <= 0) |
3050 | *mhp = 0; | |
3051 | ||
8faa8b07 AK |
3052 | /* |
3053 | * Global state is always initialized later in hugetlb_init. | |
3054 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
3055 | * use the bootmem allocator. | |
3056 | */ | |
47d38344 | 3057 | if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) |
8faa8b07 AK |
3058 | hugetlb_hstate_alloc_pages(parsed_hstate); |
3059 | ||
3060 | last_mhp = mhp; | |
3061 | ||
a3437870 NA |
3062 | return 1; |
3063 | } | |
e11bfbfc NP |
3064 | __setup("hugepages=", hugetlb_nrpages_setup); |
3065 | ||
3066 | static int __init hugetlb_default_setup(char *s) | |
3067 | { | |
3068 | default_hstate_size = memparse(s, &s); | |
3069 | return 1; | |
3070 | } | |
3071 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 3072 | |
8a213460 NA |
3073 | static unsigned int cpuset_mems_nr(unsigned int *array) |
3074 | { | |
3075 | int node; | |
3076 | unsigned int nr = 0; | |
3077 | ||
3078 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
3079 | nr += array[node]; | |
3080 | ||
3081 | return nr; | |
3082 | } | |
3083 | ||
3084 | #ifdef CONFIG_SYSCTL | |
06808b08 LS |
3085 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
3086 | struct ctl_table *table, int write, | |
3087 | void __user *buffer, size_t *length, loff_t *ppos) | |
1da177e4 | 3088 | { |
e5ff2159 | 3089 | struct hstate *h = &default_hstate; |
238d3c13 | 3090 | unsigned long tmp = h->max_huge_pages; |
08d4a246 | 3091 | int ret; |
e5ff2159 | 3092 | |
457c1b27 | 3093 | if (!hugepages_supported()) |
86613628 | 3094 | return -EOPNOTSUPP; |
457c1b27 | 3095 | |
e5ff2159 AK |
3096 | table->data = &tmp; |
3097 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
3098 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
3099 | if (ret) | |
3100 | goto out; | |
e5ff2159 | 3101 | |
238d3c13 DR |
3102 | if (write) |
3103 | ret = __nr_hugepages_store_common(obey_mempolicy, h, | |
3104 | NUMA_NO_NODE, tmp, *length); | |
08d4a246 MH |
3105 | out: |
3106 | return ret; | |
1da177e4 | 3107 | } |
396faf03 | 3108 | |
06808b08 LS |
3109 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
3110 | void __user *buffer, size_t *length, loff_t *ppos) | |
3111 | { | |
3112 | ||
3113 | return hugetlb_sysctl_handler_common(false, table, write, | |
3114 | buffer, length, ppos); | |
3115 | } | |
3116 | ||
3117 | #ifdef CONFIG_NUMA | |
3118 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, | |
3119 | void __user *buffer, size_t *length, loff_t *ppos) | |
3120 | { | |
3121 | return hugetlb_sysctl_handler_common(true, table, write, | |
3122 | buffer, length, ppos); | |
3123 | } | |
3124 | #endif /* CONFIG_NUMA */ | |
3125 | ||
a3d0c6aa | 3126 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
8d65af78 | 3127 | void __user *buffer, |
a3d0c6aa NA |
3128 | size_t *length, loff_t *ppos) |
3129 | { | |
a5516438 | 3130 | struct hstate *h = &default_hstate; |
e5ff2159 | 3131 | unsigned long tmp; |
08d4a246 | 3132 | int ret; |
e5ff2159 | 3133 | |
457c1b27 | 3134 | if (!hugepages_supported()) |
86613628 | 3135 | return -EOPNOTSUPP; |
457c1b27 | 3136 | |
c033a93c | 3137 | tmp = h->nr_overcommit_huge_pages; |
e5ff2159 | 3138 | |
bae7f4ae | 3139 | if (write && hstate_is_gigantic(h)) |
adbe8726 EM |
3140 | return -EINVAL; |
3141 | ||
e5ff2159 AK |
3142 | table->data = &tmp; |
3143 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
3144 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
3145 | if (ret) | |
3146 | goto out; | |
e5ff2159 AK |
3147 | |
3148 | if (write) { | |
3149 | spin_lock(&hugetlb_lock); | |
3150 | h->nr_overcommit_huge_pages = tmp; | |
3151 | spin_unlock(&hugetlb_lock); | |
3152 | } | |
08d4a246 MH |
3153 | out: |
3154 | return ret; | |
a3d0c6aa NA |
3155 | } |
3156 | ||
1da177e4 LT |
3157 | #endif /* CONFIG_SYSCTL */ |
3158 | ||
e1759c21 | 3159 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 3160 | { |
fcb2b0c5 RG |
3161 | struct hstate *h; |
3162 | unsigned long total = 0; | |
3163 | ||
457c1b27 NA |
3164 | if (!hugepages_supported()) |
3165 | return; | |
fcb2b0c5 RG |
3166 | |
3167 | for_each_hstate(h) { | |
3168 | unsigned long count = h->nr_huge_pages; | |
3169 | ||
3170 | total += (PAGE_SIZE << huge_page_order(h)) * count; | |
3171 | ||
3172 | if (h == &default_hstate) | |
3173 | seq_printf(m, | |
3174 | "HugePages_Total: %5lu\n" | |
3175 | "HugePages_Free: %5lu\n" | |
3176 | "HugePages_Rsvd: %5lu\n" | |
3177 | "HugePages_Surp: %5lu\n" | |
3178 | "Hugepagesize: %8lu kB\n", | |
3179 | count, | |
3180 | h->free_huge_pages, | |
3181 | h->resv_huge_pages, | |
3182 | h->surplus_huge_pages, | |
3183 | (PAGE_SIZE << huge_page_order(h)) / 1024); | |
3184 | } | |
3185 | ||
3186 | seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); | |
1da177e4 LT |
3187 | } |
3188 | ||
3189 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
3190 | { | |
a5516438 | 3191 | struct hstate *h = &default_hstate; |
457c1b27 NA |
3192 | if (!hugepages_supported()) |
3193 | return 0; | |
1da177e4 LT |
3194 | return sprintf(buf, |
3195 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
3196 | "Node %d HugePages_Free: %5u\n" |
3197 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
3198 | nid, h->nr_huge_pages_node[nid], |
3199 | nid, h->free_huge_pages_node[nid], | |
3200 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
3201 | } |
3202 | ||
949f7ec5 DR |
3203 | void hugetlb_show_meminfo(void) |
3204 | { | |
3205 | struct hstate *h; | |
3206 | int nid; | |
3207 | ||
457c1b27 NA |
3208 | if (!hugepages_supported()) |
3209 | return; | |
3210 | ||
949f7ec5 DR |
3211 | for_each_node_state(nid, N_MEMORY) |
3212 | for_each_hstate(h) | |
3213 | pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", | |
3214 | nid, | |
3215 | h->nr_huge_pages_node[nid], | |
3216 | h->free_huge_pages_node[nid], | |
3217 | h->surplus_huge_pages_node[nid], | |
3218 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
3219 | } | |
3220 | ||
5d317b2b NH |
3221 | void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) |
3222 | { | |
3223 | seq_printf(m, "HugetlbPages:\t%8lu kB\n", | |
3224 | atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); | |
3225 | } | |
3226 | ||
1da177e4 LT |
3227 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
3228 | unsigned long hugetlb_total_pages(void) | |
3229 | { | |
d0028588 WL |
3230 | struct hstate *h; |
3231 | unsigned long nr_total_pages = 0; | |
3232 | ||
3233 | for_each_hstate(h) | |
3234 | nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); | |
3235 | return nr_total_pages; | |
1da177e4 | 3236 | } |
1da177e4 | 3237 | |
a5516438 | 3238 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
3239 | { |
3240 | int ret = -ENOMEM; | |
3241 | ||
3242 | spin_lock(&hugetlb_lock); | |
3243 | /* | |
3244 | * When cpuset is configured, it breaks the strict hugetlb page | |
3245 | * reservation as the accounting is done on a global variable. Such | |
3246 | * reservation is completely rubbish in the presence of cpuset because | |
3247 | * the reservation is not checked against page availability for the | |
3248 | * current cpuset. Application can still potentially OOM'ed by kernel | |
3249 | * with lack of free htlb page in cpuset that the task is in. | |
3250 | * Attempt to enforce strict accounting with cpuset is almost | |
3251 | * impossible (or too ugly) because cpuset is too fluid that | |
3252 | * task or memory node can be dynamically moved between cpusets. | |
3253 | * | |
3254 | * The change of semantics for shared hugetlb mapping with cpuset is | |
3255 | * undesirable. However, in order to preserve some of the semantics, | |
3256 | * we fall back to check against current free page availability as | |
3257 | * a best attempt and hopefully to minimize the impact of changing | |
3258 | * semantics that cpuset has. | |
3259 | */ | |
3260 | if (delta > 0) { | |
a5516438 | 3261 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
3262 | goto out; |
3263 | ||
a5516438 AK |
3264 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
3265 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
3266 | goto out; |
3267 | } | |
3268 | } | |
3269 | ||
3270 | ret = 0; | |
3271 | if (delta < 0) | |
a5516438 | 3272 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
3273 | |
3274 | out: | |
3275 | spin_unlock(&hugetlb_lock); | |
3276 | return ret; | |
3277 | } | |
3278 | ||
84afd99b AW |
3279 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
3280 | { | |
f522c3ac | 3281 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b AW |
3282 | |
3283 | /* | |
3284 | * This new VMA should share its siblings reservation map if present. | |
3285 | * The VMA will only ever have a valid reservation map pointer where | |
3286 | * it is being copied for another still existing VMA. As that VMA | |
25985edc | 3287 | * has a reference to the reservation map it cannot disappear until |
84afd99b AW |
3288 | * after this open call completes. It is therefore safe to take a |
3289 | * new reference here without additional locking. | |
3290 | */ | |
4e35f483 | 3291 | if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
f522c3ac | 3292 | kref_get(&resv->refs); |
84afd99b AW |
3293 | } |
3294 | ||
a1e78772 MG |
3295 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
3296 | { | |
a5516438 | 3297 | struct hstate *h = hstate_vma(vma); |
f522c3ac | 3298 | struct resv_map *resv = vma_resv_map(vma); |
90481622 | 3299 | struct hugepage_subpool *spool = subpool_vma(vma); |
4e35f483 | 3300 | unsigned long reserve, start, end; |
1c5ecae3 | 3301 | long gbl_reserve; |
84afd99b | 3302 | |
4e35f483 JK |
3303 | if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
3304 | return; | |
84afd99b | 3305 | |
4e35f483 JK |
3306 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
3307 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b | 3308 | |
4e35f483 | 3309 | reserve = (end - start) - region_count(resv, start, end); |
84afd99b | 3310 | |
4e35f483 JK |
3311 | kref_put(&resv->refs, resv_map_release); |
3312 | ||
3313 | if (reserve) { | |
1c5ecae3 MK |
3314 | /* |
3315 | * Decrement reserve counts. The global reserve count may be | |
3316 | * adjusted if the subpool has a minimum size. | |
3317 | */ | |
3318 | gbl_reserve = hugepage_subpool_put_pages(spool, reserve); | |
3319 | hugetlb_acct_memory(h, -gbl_reserve); | |
84afd99b | 3320 | } |
a1e78772 MG |
3321 | } |
3322 | ||
31383c68 DW |
3323 | static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) |
3324 | { | |
3325 | if (addr & ~(huge_page_mask(hstate_vma(vma)))) | |
3326 | return -EINVAL; | |
3327 | return 0; | |
3328 | } | |
3329 | ||
05ea8860 DW |
3330 | static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) |
3331 | { | |
3332 | struct hstate *hstate = hstate_vma(vma); | |
3333 | ||
3334 | return 1UL << huge_page_shift(hstate); | |
3335 | } | |
3336 | ||
1da177e4 LT |
3337 | /* |
3338 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
3339 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
3340 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
3341 | * this far. | |
3342 | */ | |
b3ec9f33 | 3343 | static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) |
1da177e4 LT |
3344 | { |
3345 | BUG(); | |
d0217ac0 | 3346 | return 0; |
1da177e4 LT |
3347 | } |
3348 | ||
eec3636a JC |
3349 | /* |
3350 | * When a new function is introduced to vm_operations_struct and added | |
3351 | * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. | |
3352 | * This is because under System V memory model, mappings created via | |
3353 | * shmget/shmat with "huge page" specified are backed by hugetlbfs files, | |
3354 | * their original vm_ops are overwritten with shm_vm_ops. | |
3355 | */ | |
f0f37e2f | 3356 | const struct vm_operations_struct hugetlb_vm_ops = { |
d0217ac0 | 3357 | .fault = hugetlb_vm_op_fault, |
84afd99b | 3358 | .open = hugetlb_vm_op_open, |
a1e78772 | 3359 | .close = hugetlb_vm_op_close, |
31383c68 | 3360 | .split = hugetlb_vm_op_split, |
05ea8860 | 3361 | .pagesize = hugetlb_vm_op_pagesize, |
1da177e4 LT |
3362 | }; |
3363 | ||
1e8f889b DG |
3364 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
3365 | int writable) | |
63551ae0 DG |
3366 | { |
3367 | pte_t entry; | |
3368 | ||
1e8f889b | 3369 | if (writable) { |
106c992a GS |
3370 | entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, |
3371 | vma->vm_page_prot))); | |
63551ae0 | 3372 | } else { |
106c992a GS |
3373 | entry = huge_pte_wrprotect(mk_huge_pte(page, |
3374 | vma->vm_page_prot)); | |
63551ae0 DG |
3375 | } |
3376 | entry = pte_mkyoung(entry); | |
3377 | entry = pte_mkhuge(entry); | |
d9ed9faa | 3378 | entry = arch_make_huge_pte(entry, vma, page, writable); |
63551ae0 DG |
3379 | |
3380 | return entry; | |
3381 | } | |
3382 | ||
1e8f889b DG |
3383 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
3384 | unsigned long address, pte_t *ptep) | |
3385 | { | |
3386 | pte_t entry; | |
3387 | ||
106c992a | 3388 | entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); |
32f84528 | 3389 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) |
4b3073e1 | 3390 | update_mmu_cache(vma, address, ptep); |
1e8f889b DG |
3391 | } |
3392 | ||
d5ed7444 | 3393 | bool is_hugetlb_entry_migration(pte_t pte) |
4a705fef NH |
3394 | { |
3395 | swp_entry_t swp; | |
3396 | ||
3397 | if (huge_pte_none(pte) || pte_present(pte)) | |
d5ed7444 | 3398 | return false; |
4a705fef NH |
3399 | swp = pte_to_swp_entry(pte); |
3400 | if (non_swap_entry(swp) && is_migration_entry(swp)) | |
d5ed7444 | 3401 | return true; |
4a705fef | 3402 | else |
d5ed7444 | 3403 | return false; |
4a705fef NH |
3404 | } |
3405 | ||
3406 | static int is_hugetlb_entry_hwpoisoned(pte_t pte) | |
3407 | { | |
3408 | swp_entry_t swp; | |
3409 | ||
3410 | if (huge_pte_none(pte) || pte_present(pte)) | |
3411 | return 0; | |
3412 | swp = pte_to_swp_entry(pte); | |
3413 | if (non_swap_entry(swp) && is_hwpoison_entry(swp)) | |
3414 | return 1; | |
3415 | else | |
3416 | return 0; | |
3417 | } | |
1e8f889b | 3418 | |
63551ae0 DG |
3419 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
3420 | struct vm_area_struct *vma) | |
3421 | { | |
5e41540c | 3422 | pte_t *src_pte, *dst_pte, entry, dst_entry; |
63551ae0 | 3423 | struct page *ptepage; |
1c59827d | 3424 | unsigned long addr; |
1e8f889b | 3425 | int cow; |
a5516438 AK |
3426 | struct hstate *h = hstate_vma(vma); |
3427 | unsigned long sz = huge_page_size(h); | |
ac46d4f3 | 3428 | struct mmu_notifier_range range; |
e8569dd2 | 3429 | int ret = 0; |
1e8f889b DG |
3430 | |
3431 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 3432 | |
ac46d4f3 | 3433 | if (cow) { |
7269f999 | 3434 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, |
6f4f13e8 | 3435 | vma->vm_start, |
ac46d4f3 JG |
3436 | vma->vm_end); |
3437 | mmu_notifier_invalidate_range_start(&range); | |
3438 | } | |
e8569dd2 | 3439 | |
a5516438 | 3440 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
cb900f41 | 3441 | spinlock_t *src_ptl, *dst_ptl; |
7868a208 | 3442 | src_pte = huge_pte_offset(src, addr, sz); |
c74df32c HD |
3443 | if (!src_pte) |
3444 | continue; | |
a5516438 | 3445 | dst_pte = huge_pte_alloc(dst, addr, sz); |
e8569dd2 AS |
3446 | if (!dst_pte) { |
3447 | ret = -ENOMEM; | |
3448 | break; | |
3449 | } | |
c5c99429 | 3450 | |
5e41540c MK |
3451 | /* |
3452 | * If the pagetables are shared don't copy or take references. | |
3453 | * dst_pte == src_pte is the common case of src/dest sharing. | |
3454 | * | |
3455 | * However, src could have 'unshared' and dst shares with | |
3456 | * another vma. If dst_pte !none, this implies sharing. | |
3457 | * Check here before taking page table lock, and once again | |
3458 | * after taking the lock below. | |
3459 | */ | |
3460 | dst_entry = huge_ptep_get(dst_pte); | |
3461 | if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) | |
c5c99429 LW |
3462 | continue; |
3463 | ||
cb900f41 KS |
3464 | dst_ptl = huge_pte_lock(h, dst, dst_pte); |
3465 | src_ptl = huge_pte_lockptr(h, src, src_pte); | |
3466 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
4a705fef | 3467 | entry = huge_ptep_get(src_pte); |
5e41540c MK |
3468 | dst_entry = huge_ptep_get(dst_pte); |
3469 | if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { | |
3470 | /* | |
3471 | * Skip if src entry none. Also, skip in the | |
3472 | * unlikely case dst entry !none as this implies | |
3473 | * sharing with another vma. | |
3474 | */ | |
4a705fef NH |
3475 | ; |
3476 | } else if (unlikely(is_hugetlb_entry_migration(entry) || | |
3477 | is_hugetlb_entry_hwpoisoned(entry))) { | |
3478 | swp_entry_t swp_entry = pte_to_swp_entry(entry); | |
3479 | ||
3480 | if (is_write_migration_entry(swp_entry) && cow) { | |
3481 | /* | |
3482 | * COW mappings require pages in both | |
3483 | * parent and child to be set to read. | |
3484 | */ | |
3485 | make_migration_entry_read(&swp_entry); | |
3486 | entry = swp_entry_to_pte(swp_entry); | |
e5251fd4 PA |
3487 | set_huge_swap_pte_at(src, addr, src_pte, |
3488 | entry, sz); | |
4a705fef | 3489 | } |
e5251fd4 | 3490 | set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); |
4a705fef | 3491 | } else { |
34ee645e | 3492 | if (cow) { |
0f10851e JG |
3493 | /* |
3494 | * No need to notify as we are downgrading page | |
3495 | * table protection not changing it to point | |
3496 | * to a new page. | |
3497 | * | |
ad56b738 | 3498 | * See Documentation/vm/mmu_notifier.rst |
0f10851e | 3499 | */ |
7f2e9525 | 3500 | huge_ptep_set_wrprotect(src, addr, src_pte); |
34ee645e | 3501 | } |
0253d634 | 3502 | entry = huge_ptep_get(src_pte); |
1c59827d HD |
3503 | ptepage = pte_page(entry); |
3504 | get_page(ptepage); | |
53f9263b | 3505 | page_dup_rmap(ptepage, true); |
1c59827d | 3506 | set_huge_pte_at(dst, addr, dst_pte, entry); |
5d317b2b | 3507 | hugetlb_count_add(pages_per_huge_page(h), dst); |
1c59827d | 3508 | } |
cb900f41 KS |
3509 | spin_unlock(src_ptl); |
3510 | spin_unlock(dst_ptl); | |
63551ae0 | 3511 | } |
63551ae0 | 3512 | |
e8569dd2 | 3513 | if (cow) |
ac46d4f3 | 3514 | mmu_notifier_invalidate_range_end(&range); |
e8569dd2 AS |
3515 | |
3516 | return ret; | |
63551ae0 DG |
3517 | } |
3518 | ||
24669e58 AK |
3519 | void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, |
3520 | unsigned long start, unsigned long end, | |
3521 | struct page *ref_page) | |
63551ae0 DG |
3522 | { |
3523 | struct mm_struct *mm = vma->vm_mm; | |
3524 | unsigned long address; | |
c7546f8f | 3525 | pte_t *ptep; |
63551ae0 | 3526 | pte_t pte; |
cb900f41 | 3527 | spinlock_t *ptl; |
63551ae0 | 3528 | struct page *page; |
a5516438 AK |
3529 | struct hstate *h = hstate_vma(vma); |
3530 | unsigned long sz = huge_page_size(h); | |
ac46d4f3 | 3531 | struct mmu_notifier_range range; |
a5516438 | 3532 | |
63551ae0 | 3533 | WARN_ON(!is_vm_hugetlb_page(vma)); |
a5516438 AK |
3534 | BUG_ON(start & ~huge_page_mask(h)); |
3535 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 3536 | |
07e32661 AK |
3537 | /* |
3538 | * This is a hugetlb vma, all the pte entries should point | |
3539 | * to huge page. | |
3540 | */ | |
ed6a7935 | 3541 | tlb_change_page_size(tlb, sz); |
24669e58 | 3542 | tlb_start_vma(tlb, vma); |
dff11abe MK |
3543 | |
3544 | /* | |
3545 | * If sharing possible, alert mmu notifiers of worst case. | |
3546 | */ | |
6f4f13e8 JG |
3547 | mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, |
3548 | end); | |
ac46d4f3 JG |
3549 | adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); |
3550 | mmu_notifier_invalidate_range_start(&range); | |
569f48b8 | 3551 | address = start; |
569f48b8 | 3552 | for (; address < end; address += sz) { |
7868a208 | 3553 | ptep = huge_pte_offset(mm, address, sz); |
4c887265 | 3554 | if (!ptep) |
c7546f8f DG |
3555 | continue; |
3556 | ||
cb900f41 | 3557 | ptl = huge_pte_lock(h, mm, ptep); |
31d49da5 AK |
3558 | if (huge_pmd_unshare(mm, &address, ptep)) { |
3559 | spin_unlock(ptl); | |
dff11abe MK |
3560 | /* |
3561 | * We just unmapped a page of PMDs by clearing a PUD. | |
3562 | * The caller's TLB flush range should cover this area. | |
3563 | */ | |
31d49da5 AK |
3564 | continue; |
3565 | } | |
39dde65c | 3566 | |
6629326b | 3567 | pte = huge_ptep_get(ptep); |
31d49da5 AK |
3568 | if (huge_pte_none(pte)) { |
3569 | spin_unlock(ptl); | |
3570 | continue; | |
3571 | } | |
6629326b HD |
3572 | |
3573 | /* | |
9fbc1f63 NH |
3574 | * Migrating hugepage or HWPoisoned hugepage is already |
3575 | * unmapped and its refcount is dropped, so just clear pte here. | |
6629326b | 3576 | */ |
9fbc1f63 | 3577 | if (unlikely(!pte_present(pte))) { |
9386fac3 | 3578 | huge_pte_clear(mm, address, ptep, sz); |
31d49da5 AK |
3579 | spin_unlock(ptl); |
3580 | continue; | |
8c4894c6 | 3581 | } |
6629326b HD |
3582 | |
3583 | page = pte_page(pte); | |
04f2cbe3 MG |
3584 | /* |
3585 | * If a reference page is supplied, it is because a specific | |
3586 | * page is being unmapped, not a range. Ensure the page we | |
3587 | * are about to unmap is the actual page of interest. | |
3588 | */ | |
3589 | if (ref_page) { | |
31d49da5 AK |
3590 | if (page != ref_page) { |
3591 | spin_unlock(ptl); | |
3592 | continue; | |
3593 | } | |
04f2cbe3 MG |
3594 | /* |
3595 | * Mark the VMA as having unmapped its page so that | |
3596 | * future faults in this VMA will fail rather than | |
3597 | * looking like data was lost | |
3598 | */ | |
3599 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
3600 | } | |
3601 | ||
c7546f8f | 3602 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
b528e4b6 | 3603 | tlb_remove_huge_tlb_entry(h, tlb, ptep, address); |
106c992a | 3604 | if (huge_pte_dirty(pte)) |
6649a386 | 3605 | set_page_dirty(page); |
9e81130b | 3606 | |
5d317b2b | 3607 | hugetlb_count_sub(pages_per_huge_page(h), mm); |
d281ee61 | 3608 | page_remove_rmap(page, true); |
31d49da5 | 3609 | |
cb900f41 | 3610 | spin_unlock(ptl); |
e77b0852 | 3611 | tlb_remove_page_size(tlb, page, huge_page_size(h)); |
31d49da5 AK |
3612 | /* |
3613 | * Bail out after unmapping reference page if supplied | |
3614 | */ | |
3615 | if (ref_page) | |
3616 | break; | |
fe1668ae | 3617 | } |
ac46d4f3 | 3618 | mmu_notifier_invalidate_range_end(&range); |
24669e58 | 3619 | tlb_end_vma(tlb, vma); |
1da177e4 | 3620 | } |
63551ae0 | 3621 | |
d833352a MG |
3622 | void __unmap_hugepage_range_final(struct mmu_gather *tlb, |
3623 | struct vm_area_struct *vma, unsigned long start, | |
3624 | unsigned long end, struct page *ref_page) | |
3625 | { | |
3626 | __unmap_hugepage_range(tlb, vma, start, end, ref_page); | |
3627 | ||
3628 | /* | |
3629 | * Clear this flag so that x86's huge_pmd_share page_table_shareable | |
3630 | * test will fail on a vma being torn down, and not grab a page table | |
3631 | * on its way out. We're lucky that the flag has such an appropriate | |
3632 | * name, and can in fact be safely cleared here. We could clear it | |
3633 | * before the __unmap_hugepage_range above, but all that's necessary | |
c8c06efa | 3634 | * is to clear it before releasing the i_mmap_rwsem. This works |
d833352a | 3635 | * because in the context this is called, the VMA is about to be |
c8c06efa | 3636 | * destroyed and the i_mmap_rwsem is held. |
d833352a MG |
3637 | */ |
3638 | vma->vm_flags &= ~VM_MAYSHARE; | |
3639 | } | |
3640 | ||
502717f4 | 3641 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 3642 | unsigned long end, struct page *ref_page) |
502717f4 | 3643 | { |
24669e58 AK |
3644 | struct mm_struct *mm; |
3645 | struct mmu_gather tlb; | |
dff11abe MK |
3646 | unsigned long tlb_start = start; |
3647 | unsigned long tlb_end = end; | |
3648 | ||
3649 | /* | |
3650 | * If shared PMDs were possibly used within this vma range, adjust | |
3651 | * start/end for worst case tlb flushing. | |
3652 | * Note that we can not be sure if PMDs are shared until we try to | |
3653 | * unmap pages. However, we want to make sure TLB flushing covers | |
3654 | * the largest possible range. | |
3655 | */ | |
3656 | adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end); | |
24669e58 AK |
3657 | |
3658 | mm = vma->vm_mm; | |
3659 | ||
dff11abe | 3660 | tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end); |
24669e58 | 3661 | __unmap_hugepage_range(&tlb, vma, start, end, ref_page); |
dff11abe | 3662 | tlb_finish_mmu(&tlb, tlb_start, tlb_end); |
502717f4 KC |
3663 | } |
3664 | ||
04f2cbe3 MG |
3665 | /* |
3666 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
3667 | * mappping it owns the reserve page for. The intention is to unmap the page | |
3668 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
3669 | * same region. | |
3670 | */ | |
2f4612af DB |
3671 | static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
3672 | struct page *page, unsigned long address) | |
04f2cbe3 | 3673 | { |
7526674d | 3674 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
3675 | struct vm_area_struct *iter_vma; |
3676 | struct address_space *mapping; | |
04f2cbe3 MG |
3677 | pgoff_t pgoff; |
3678 | ||
3679 | /* | |
3680 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
3681 | * from page cache lookup which is in HPAGE_SIZE units. | |
3682 | */ | |
7526674d | 3683 | address = address & huge_page_mask(h); |
36e4f20a MH |
3684 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + |
3685 | vma->vm_pgoff; | |
93c76a3d | 3686 | mapping = vma->vm_file->f_mapping; |
04f2cbe3 | 3687 | |
4eb2b1dc MG |
3688 | /* |
3689 | * Take the mapping lock for the duration of the table walk. As | |
3690 | * this mapping should be shared between all the VMAs, | |
3691 | * __unmap_hugepage_range() is called as the lock is already held | |
3692 | */ | |
83cde9e8 | 3693 | i_mmap_lock_write(mapping); |
6b2dbba8 | 3694 | vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { |
04f2cbe3 MG |
3695 | /* Do not unmap the current VMA */ |
3696 | if (iter_vma == vma) | |
3697 | continue; | |
3698 | ||
2f84a899 MG |
3699 | /* |
3700 | * Shared VMAs have their own reserves and do not affect | |
3701 | * MAP_PRIVATE accounting but it is possible that a shared | |
3702 | * VMA is using the same page so check and skip such VMAs. | |
3703 | */ | |
3704 | if (iter_vma->vm_flags & VM_MAYSHARE) | |
3705 | continue; | |
3706 | ||
04f2cbe3 MG |
3707 | /* |
3708 | * Unmap the page from other VMAs without their own reserves. | |
3709 | * They get marked to be SIGKILLed if they fault in these | |
3710 | * areas. This is because a future no-page fault on this VMA | |
3711 | * could insert a zeroed page instead of the data existing | |
3712 | * from the time of fork. This would look like data corruption | |
3713 | */ | |
3714 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
24669e58 AK |
3715 | unmap_hugepage_range(iter_vma, address, |
3716 | address + huge_page_size(h), page); | |
04f2cbe3 | 3717 | } |
83cde9e8 | 3718 | i_mmap_unlock_write(mapping); |
04f2cbe3 MG |
3719 | } |
3720 | ||
0fe6e20b NH |
3721 | /* |
3722 | * Hugetlb_cow() should be called with page lock of the original hugepage held. | |
ef009b25 MH |
3723 | * Called with hugetlb_instantiation_mutex held and pte_page locked so we |
3724 | * cannot race with other handlers or page migration. | |
3725 | * Keep the pte_same checks anyway to make transition from the mutex easier. | |
0fe6e20b | 3726 | */ |
2b740303 | 3727 | static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
974e6d66 | 3728 | unsigned long address, pte_t *ptep, |
3999f52e | 3729 | struct page *pagecache_page, spinlock_t *ptl) |
1e8f889b | 3730 | { |
3999f52e | 3731 | pte_t pte; |
a5516438 | 3732 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 3733 | struct page *old_page, *new_page; |
2b740303 SJ |
3734 | int outside_reserve = 0; |
3735 | vm_fault_t ret = 0; | |
974e6d66 | 3736 | unsigned long haddr = address & huge_page_mask(h); |
ac46d4f3 | 3737 | struct mmu_notifier_range range; |
1e8f889b | 3738 | |
3999f52e | 3739 | pte = huge_ptep_get(ptep); |
1e8f889b DG |
3740 | old_page = pte_page(pte); |
3741 | ||
04f2cbe3 | 3742 | retry_avoidcopy: |
1e8f889b DG |
3743 | /* If no-one else is actually using this page, avoid the copy |
3744 | * and just make the page writable */ | |
37a2140d | 3745 | if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { |
5a49973d | 3746 | page_move_anon_rmap(old_page, vma); |
5b7a1d40 | 3747 | set_huge_ptep_writable(vma, haddr, ptep); |
83c54070 | 3748 | return 0; |
1e8f889b DG |
3749 | } |
3750 | ||
04f2cbe3 MG |
3751 | /* |
3752 | * If the process that created a MAP_PRIVATE mapping is about to | |
3753 | * perform a COW due to a shared page count, attempt to satisfy | |
3754 | * the allocation without using the existing reserves. The pagecache | |
3755 | * page is used to determine if the reserve at this address was | |
3756 | * consumed or not. If reserves were used, a partial faulted mapping | |
3757 | * at the time of fork() could consume its reserves on COW instead | |
3758 | * of the full address range. | |
3759 | */ | |
5944d011 | 3760 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
04f2cbe3 MG |
3761 | old_page != pagecache_page) |
3762 | outside_reserve = 1; | |
3763 | ||
09cbfeaf | 3764 | get_page(old_page); |
b76c8cfb | 3765 | |
ad4404a2 DB |
3766 | /* |
3767 | * Drop page table lock as buddy allocator may be called. It will | |
3768 | * be acquired again before returning to the caller, as expected. | |
3769 | */ | |
cb900f41 | 3770 | spin_unlock(ptl); |
5b7a1d40 | 3771 | new_page = alloc_huge_page(vma, haddr, outside_reserve); |
1e8f889b | 3772 | |
2fc39cec | 3773 | if (IS_ERR(new_page)) { |
04f2cbe3 MG |
3774 | /* |
3775 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
3776 | * it is due to references held by a child and an insufficient | |
3777 | * huge page pool. To guarantee the original mappers | |
3778 | * reliability, unmap the page from child processes. The child | |
3779 | * may get SIGKILLed if it later faults. | |
3780 | */ | |
3781 | if (outside_reserve) { | |
09cbfeaf | 3782 | put_page(old_page); |
04f2cbe3 | 3783 | BUG_ON(huge_pte_none(pte)); |
5b7a1d40 | 3784 | unmap_ref_private(mm, vma, old_page, haddr); |
2f4612af DB |
3785 | BUG_ON(huge_pte_none(pte)); |
3786 | spin_lock(ptl); | |
5b7a1d40 | 3787 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
2f4612af DB |
3788 | if (likely(ptep && |
3789 | pte_same(huge_ptep_get(ptep), pte))) | |
3790 | goto retry_avoidcopy; | |
3791 | /* | |
3792 | * race occurs while re-acquiring page table | |
3793 | * lock, and our job is done. | |
3794 | */ | |
3795 | return 0; | |
04f2cbe3 MG |
3796 | } |
3797 | ||
2b740303 | 3798 | ret = vmf_error(PTR_ERR(new_page)); |
ad4404a2 | 3799 | goto out_release_old; |
1e8f889b DG |
3800 | } |
3801 | ||
0fe6e20b NH |
3802 | /* |
3803 | * When the original hugepage is shared one, it does not have | |
3804 | * anon_vma prepared. | |
3805 | */ | |
44e2aa93 | 3806 | if (unlikely(anon_vma_prepare(vma))) { |
ad4404a2 DB |
3807 | ret = VM_FAULT_OOM; |
3808 | goto out_release_all; | |
44e2aa93 | 3809 | } |
0fe6e20b | 3810 | |
974e6d66 | 3811 | copy_user_huge_page(new_page, old_page, address, vma, |
47ad8475 | 3812 | pages_per_huge_page(h)); |
0ed361de | 3813 | __SetPageUptodate(new_page); |
1e8f889b | 3814 | |
7269f999 | 3815 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, |
6f4f13e8 | 3816 | haddr + huge_page_size(h)); |
ac46d4f3 | 3817 | mmu_notifier_invalidate_range_start(&range); |
ad4404a2 | 3818 | |
b76c8cfb | 3819 | /* |
cb900f41 | 3820 | * Retake the page table lock to check for racing updates |
b76c8cfb LW |
3821 | * before the page tables are altered |
3822 | */ | |
cb900f41 | 3823 | spin_lock(ptl); |
5b7a1d40 | 3824 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
a9af0c5d | 3825 | if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { |
07443a85 JK |
3826 | ClearPagePrivate(new_page); |
3827 | ||
1e8f889b | 3828 | /* Break COW */ |
5b7a1d40 | 3829 | huge_ptep_clear_flush(vma, haddr, ptep); |
ac46d4f3 | 3830 | mmu_notifier_invalidate_range(mm, range.start, range.end); |
5b7a1d40 | 3831 | set_huge_pte_at(mm, haddr, ptep, |
1e8f889b | 3832 | make_huge_pte(vma, new_page, 1)); |
d281ee61 | 3833 | page_remove_rmap(old_page, true); |
5b7a1d40 | 3834 | hugepage_add_new_anon_rmap(new_page, vma, haddr); |
cb6acd01 | 3835 | set_page_huge_active(new_page); |
1e8f889b DG |
3836 | /* Make the old page be freed below */ |
3837 | new_page = old_page; | |
3838 | } | |
cb900f41 | 3839 | spin_unlock(ptl); |
ac46d4f3 | 3840 | mmu_notifier_invalidate_range_end(&range); |
ad4404a2 | 3841 | out_release_all: |
5b7a1d40 | 3842 | restore_reserve_on_error(h, vma, haddr, new_page); |
09cbfeaf | 3843 | put_page(new_page); |
ad4404a2 | 3844 | out_release_old: |
09cbfeaf | 3845 | put_page(old_page); |
8312034f | 3846 | |
ad4404a2 DB |
3847 | spin_lock(ptl); /* Caller expects lock to be held */ |
3848 | return ret; | |
1e8f889b DG |
3849 | } |
3850 | ||
04f2cbe3 | 3851 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
3852 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
3853 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
3854 | { |
3855 | struct address_space *mapping; | |
e7c4b0bf | 3856 | pgoff_t idx; |
04f2cbe3 MG |
3857 | |
3858 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 3859 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
3860 | |
3861 | return find_lock_page(mapping, idx); | |
3862 | } | |
3863 | ||
3ae77f43 HD |
3864 | /* |
3865 | * Return whether there is a pagecache page to back given address within VMA. | |
3866 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. | |
3867 | */ | |
3868 | static bool hugetlbfs_pagecache_present(struct hstate *h, | |
2a15efc9 HD |
3869 | struct vm_area_struct *vma, unsigned long address) |
3870 | { | |
3871 | struct address_space *mapping; | |
3872 | pgoff_t idx; | |
3873 | struct page *page; | |
3874 | ||
3875 | mapping = vma->vm_file->f_mapping; | |
3876 | idx = vma_hugecache_offset(h, vma, address); | |
3877 | ||
3878 | page = find_get_page(mapping, idx); | |
3879 | if (page) | |
3880 | put_page(page); | |
3881 | return page != NULL; | |
3882 | } | |
3883 | ||
ab76ad54 MK |
3884 | int huge_add_to_page_cache(struct page *page, struct address_space *mapping, |
3885 | pgoff_t idx) | |
3886 | { | |
3887 | struct inode *inode = mapping->host; | |
3888 | struct hstate *h = hstate_inode(inode); | |
3889 | int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
3890 | ||
3891 | if (err) | |
3892 | return err; | |
3893 | ClearPagePrivate(page); | |
3894 | ||
22146c3c MK |
3895 | /* |
3896 | * set page dirty so that it will not be removed from cache/file | |
3897 | * by non-hugetlbfs specific code paths. | |
3898 | */ | |
3899 | set_page_dirty(page); | |
3900 | ||
ab76ad54 MK |
3901 | spin_lock(&inode->i_lock); |
3902 | inode->i_blocks += blocks_per_huge_page(h); | |
3903 | spin_unlock(&inode->i_lock); | |
3904 | return 0; | |
3905 | } | |
3906 | ||
2b740303 SJ |
3907 | static vm_fault_t hugetlb_no_page(struct mm_struct *mm, |
3908 | struct vm_area_struct *vma, | |
3909 | struct address_space *mapping, pgoff_t idx, | |
3910 | unsigned long address, pte_t *ptep, unsigned int flags) | |
ac9b9c66 | 3911 | { |
a5516438 | 3912 | struct hstate *h = hstate_vma(vma); |
2b740303 | 3913 | vm_fault_t ret = VM_FAULT_SIGBUS; |
409eb8c2 | 3914 | int anon_rmap = 0; |
4c887265 | 3915 | unsigned long size; |
4c887265 | 3916 | struct page *page; |
1e8f889b | 3917 | pte_t new_pte; |
cb900f41 | 3918 | spinlock_t *ptl; |
285b8dca | 3919 | unsigned long haddr = address & huge_page_mask(h); |
cb6acd01 | 3920 | bool new_page = false; |
4c887265 | 3921 | |
04f2cbe3 MG |
3922 | /* |
3923 | * Currently, we are forced to kill the process in the event the | |
3924 | * original mapper has unmapped pages from the child due to a failed | |
25985edc | 3925 | * COW. Warn that such a situation has occurred as it may not be obvious |
04f2cbe3 MG |
3926 | */ |
3927 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
910154d5 | 3928 | pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", |
ffb22af5 | 3929 | current->pid); |
04f2cbe3 MG |
3930 | return ret; |
3931 | } | |
3932 | ||
4c887265 | 3933 | /* |
e7c58097 MK |
3934 | * Use page lock to guard against racing truncation |
3935 | * before we get page_table_lock. | |
4c887265 | 3936 | */ |
6bda666a CL |
3937 | retry: |
3938 | page = find_lock_page(mapping, idx); | |
3939 | if (!page) { | |
e7c58097 MK |
3940 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
3941 | if (idx >= size) | |
3942 | goto out; | |
3943 | ||
1a1aad8a MK |
3944 | /* |
3945 | * Check for page in userfault range | |
3946 | */ | |
3947 | if (userfaultfd_missing(vma)) { | |
3948 | u32 hash; | |
3949 | struct vm_fault vmf = { | |
3950 | .vma = vma, | |
285b8dca | 3951 | .address = haddr, |
1a1aad8a MK |
3952 | .flags = flags, |
3953 | /* | |
3954 | * Hard to debug if it ends up being | |
3955 | * used by a callee that assumes | |
3956 | * something about the other | |
3957 | * uninitialized fields... same as in | |
3958 | * memory.c | |
3959 | */ | |
3960 | }; | |
3961 | ||
3962 | /* | |
ddeaab32 MK |
3963 | * hugetlb_fault_mutex must be dropped before |
3964 | * handling userfault. Reacquire after handling | |
3965 | * fault to make calling code simpler. | |
1a1aad8a | 3966 | */ |
1b426bac | 3967 | hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr); |
1a1aad8a MK |
3968 | mutex_unlock(&hugetlb_fault_mutex_table[hash]); |
3969 | ret = handle_userfault(&vmf, VM_UFFD_MISSING); | |
3970 | mutex_lock(&hugetlb_fault_mutex_table[hash]); | |
3971 | goto out; | |
3972 | } | |
3973 | ||
285b8dca | 3974 | page = alloc_huge_page(vma, haddr, 0); |
2fc39cec | 3975 | if (IS_ERR(page)) { |
4643d67e MK |
3976 | /* |
3977 | * Returning error will result in faulting task being | |
3978 | * sent SIGBUS. The hugetlb fault mutex prevents two | |
3979 | * tasks from racing to fault in the same page which | |
3980 | * could result in false unable to allocate errors. | |
3981 | * Page migration does not take the fault mutex, but | |
3982 | * does a clear then write of pte's under page table | |
3983 | * lock. Page fault code could race with migration, | |
3984 | * notice the clear pte and try to allocate a page | |
3985 | * here. Before returning error, get ptl and make | |
3986 | * sure there really is no pte entry. | |
3987 | */ | |
3988 | ptl = huge_pte_lock(h, mm, ptep); | |
3989 | if (!huge_pte_none(huge_ptep_get(ptep))) { | |
3990 | ret = 0; | |
3991 | spin_unlock(ptl); | |
3992 | goto out; | |
3993 | } | |
3994 | spin_unlock(ptl); | |
2b740303 | 3995 | ret = vmf_error(PTR_ERR(page)); |
6bda666a CL |
3996 | goto out; |
3997 | } | |
47ad8475 | 3998 | clear_huge_page(page, address, pages_per_huge_page(h)); |
0ed361de | 3999 | __SetPageUptodate(page); |
cb6acd01 | 4000 | new_page = true; |
ac9b9c66 | 4001 | |
f83a275d | 4002 | if (vma->vm_flags & VM_MAYSHARE) { |
ab76ad54 | 4003 | int err = huge_add_to_page_cache(page, mapping, idx); |
6bda666a CL |
4004 | if (err) { |
4005 | put_page(page); | |
6bda666a CL |
4006 | if (err == -EEXIST) |
4007 | goto retry; | |
4008 | goto out; | |
4009 | } | |
23be7468 | 4010 | } else { |
6bda666a | 4011 | lock_page(page); |
0fe6e20b NH |
4012 | if (unlikely(anon_vma_prepare(vma))) { |
4013 | ret = VM_FAULT_OOM; | |
4014 | goto backout_unlocked; | |
4015 | } | |
409eb8c2 | 4016 | anon_rmap = 1; |
23be7468 | 4017 | } |
0fe6e20b | 4018 | } else { |
998b4382 NH |
4019 | /* |
4020 | * If memory error occurs between mmap() and fault, some process | |
4021 | * don't have hwpoisoned swap entry for errored virtual address. | |
4022 | * So we need to block hugepage fault by PG_hwpoison bit check. | |
4023 | */ | |
4024 | if (unlikely(PageHWPoison(page))) { | |
32f84528 | 4025 | ret = VM_FAULT_HWPOISON | |
972dc4de | 4026 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
998b4382 NH |
4027 | goto backout_unlocked; |
4028 | } | |
6bda666a | 4029 | } |
1e8f889b | 4030 | |
57303d80 AW |
4031 | /* |
4032 | * If we are going to COW a private mapping later, we examine the | |
4033 | * pending reservations for this page now. This will ensure that | |
4034 | * any allocations necessary to record that reservation occur outside | |
4035 | * the spinlock. | |
4036 | */ | |
5e911373 | 4037 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
285b8dca | 4038 | if (vma_needs_reservation(h, vma, haddr) < 0) { |
2b26736c AW |
4039 | ret = VM_FAULT_OOM; |
4040 | goto backout_unlocked; | |
4041 | } | |
5e911373 | 4042 | /* Just decrements count, does not deallocate */ |
285b8dca | 4043 | vma_end_reservation(h, vma, haddr); |
5e911373 | 4044 | } |
57303d80 | 4045 | |
8bea8052 | 4046 | ptl = huge_pte_lock(h, mm, ptep); |
e7c58097 MK |
4047 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4048 | if (idx >= size) | |
4049 | goto backout; | |
4c887265 | 4050 | |
83c54070 | 4051 | ret = 0; |
7f2e9525 | 4052 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
4053 | goto backout; |
4054 | ||
07443a85 JK |
4055 | if (anon_rmap) { |
4056 | ClearPagePrivate(page); | |
285b8dca | 4057 | hugepage_add_new_anon_rmap(page, vma, haddr); |
ac714904 | 4058 | } else |
53f9263b | 4059 | page_dup_rmap(page, true); |
1e8f889b DG |
4060 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
4061 | && (vma->vm_flags & VM_SHARED))); | |
285b8dca | 4062 | set_huge_pte_at(mm, haddr, ptep, new_pte); |
1e8f889b | 4063 | |
5d317b2b | 4064 | hugetlb_count_add(pages_per_huge_page(h), mm); |
788c7df4 | 4065 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 4066 | /* Optimization, do the COW without a second fault */ |
974e6d66 | 4067 | ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); |
1e8f889b DG |
4068 | } |
4069 | ||
cb900f41 | 4070 | spin_unlock(ptl); |
cb6acd01 MK |
4071 | |
4072 | /* | |
4073 | * Only make newly allocated pages active. Existing pages found | |
4074 | * in the pagecache could be !page_huge_active() if they have been | |
4075 | * isolated for migration. | |
4076 | */ | |
4077 | if (new_page) | |
4078 | set_page_huge_active(page); | |
4079 | ||
4c887265 AL |
4080 | unlock_page(page); |
4081 | out: | |
ac9b9c66 | 4082 | return ret; |
4c887265 AL |
4083 | |
4084 | backout: | |
cb900f41 | 4085 | spin_unlock(ptl); |
2b26736c | 4086 | backout_unlocked: |
4c887265 | 4087 | unlock_page(page); |
285b8dca | 4088 | restore_reserve_on_error(h, vma, haddr, page); |
4c887265 AL |
4089 | put_page(page); |
4090 | goto out; | |
ac9b9c66 HD |
4091 | } |
4092 | ||
8382d914 | 4093 | #ifdef CONFIG_SMP |
1b426bac | 4094 | u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping, |
8382d914 DB |
4095 | pgoff_t idx, unsigned long address) |
4096 | { | |
4097 | unsigned long key[2]; | |
4098 | u32 hash; | |
4099 | ||
1b426bac MK |
4100 | key[0] = (unsigned long) mapping; |
4101 | key[1] = idx; | |
8382d914 DB |
4102 | |
4103 | hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0); | |
4104 | ||
4105 | return hash & (num_fault_mutexes - 1); | |
4106 | } | |
4107 | #else | |
4108 | /* | |
4109 | * For uniprocesor systems we always use a single mutex, so just | |
4110 | * return 0 and avoid the hashing overhead. | |
4111 | */ | |
1b426bac | 4112 | u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping, |
8382d914 DB |
4113 | pgoff_t idx, unsigned long address) |
4114 | { | |
4115 | return 0; | |
4116 | } | |
4117 | #endif | |
4118 | ||
2b740303 | 4119 | vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 4120 | unsigned long address, unsigned int flags) |
86e5216f | 4121 | { |
8382d914 | 4122 | pte_t *ptep, entry; |
cb900f41 | 4123 | spinlock_t *ptl; |
2b740303 | 4124 | vm_fault_t ret; |
8382d914 DB |
4125 | u32 hash; |
4126 | pgoff_t idx; | |
0fe6e20b | 4127 | struct page *page = NULL; |
57303d80 | 4128 | struct page *pagecache_page = NULL; |
a5516438 | 4129 | struct hstate *h = hstate_vma(vma); |
8382d914 | 4130 | struct address_space *mapping; |
0f792cf9 | 4131 | int need_wait_lock = 0; |
285b8dca | 4132 | unsigned long haddr = address & huge_page_mask(h); |
86e5216f | 4133 | |
285b8dca | 4134 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
fd6a03ed NH |
4135 | if (ptep) { |
4136 | entry = huge_ptep_get(ptep); | |
290408d4 | 4137 | if (unlikely(is_hugetlb_entry_migration(entry))) { |
cb900f41 | 4138 | migration_entry_wait_huge(vma, mm, ptep); |
290408d4 NH |
4139 | return 0; |
4140 | } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) | |
32f84528 | 4141 | return VM_FAULT_HWPOISON_LARGE | |
972dc4de | 4142 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
ddeaab32 MK |
4143 | } else { |
4144 | ptep = huge_pte_alloc(mm, haddr, huge_page_size(h)); | |
4145 | if (!ptep) | |
4146 | return VM_FAULT_OOM; | |
fd6a03ed NH |
4147 | } |
4148 | ||
8382d914 | 4149 | mapping = vma->vm_file->f_mapping; |
ddeaab32 | 4150 | idx = vma_hugecache_offset(h, vma, haddr); |
8382d914 | 4151 | |
3935baa9 DG |
4152 | /* |
4153 | * Serialize hugepage allocation and instantiation, so that we don't | |
4154 | * get spurious allocation failures if two CPUs race to instantiate | |
4155 | * the same page in the page cache. | |
4156 | */ | |
1b426bac | 4157 | hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr); |
c672c7f2 | 4158 | mutex_lock(&hugetlb_fault_mutex_table[hash]); |
8382d914 | 4159 | |
7f2e9525 GS |
4160 | entry = huge_ptep_get(ptep); |
4161 | if (huge_pte_none(entry)) { | |
8382d914 | 4162 | ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); |
b4d1d99f | 4163 | goto out_mutex; |
3935baa9 | 4164 | } |
86e5216f | 4165 | |
83c54070 | 4166 | ret = 0; |
1e8f889b | 4167 | |
0f792cf9 NH |
4168 | /* |
4169 | * entry could be a migration/hwpoison entry at this point, so this | |
4170 | * check prevents the kernel from going below assuming that we have | |
4171 | * a active hugepage in pagecache. This goto expects the 2nd page fault, | |
4172 | * and is_hugetlb_entry_(migration|hwpoisoned) check will properly | |
4173 | * handle it. | |
4174 | */ | |
4175 | if (!pte_present(entry)) | |
4176 | goto out_mutex; | |
4177 | ||
57303d80 AW |
4178 | /* |
4179 | * If we are going to COW the mapping later, we examine the pending | |
4180 | * reservations for this page now. This will ensure that any | |
4181 | * allocations necessary to record that reservation occur outside the | |
4182 | * spinlock. For private mappings, we also lookup the pagecache | |
4183 | * page now as it is used to determine if a reservation has been | |
4184 | * consumed. | |
4185 | */ | |
106c992a | 4186 | if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { |
285b8dca | 4187 | if (vma_needs_reservation(h, vma, haddr) < 0) { |
2b26736c | 4188 | ret = VM_FAULT_OOM; |
b4d1d99f | 4189 | goto out_mutex; |
2b26736c | 4190 | } |
5e911373 | 4191 | /* Just decrements count, does not deallocate */ |
285b8dca | 4192 | vma_end_reservation(h, vma, haddr); |
57303d80 | 4193 | |
f83a275d | 4194 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 | 4195 | pagecache_page = hugetlbfs_pagecache_page(h, |
285b8dca | 4196 | vma, haddr); |
57303d80 AW |
4197 | } |
4198 | ||
0f792cf9 NH |
4199 | ptl = huge_pte_lock(h, mm, ptep); |
4200 | ||
4201 | /* Check for a racing update before calling hugetlb_cow */ | |
4202 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) | |
4203 | goto out_ptl; | |
4204 | ||
56c9cfb1 NH |
4205 | /* |
4206 | * hugetlb_cow() requires page locks of pte_page(entry) and | |
4207 | * pagecache_page, so here we need take the former one | |
4208 | * when page != pagecache_page or !pagecache_page. | |
56c9cfb1 NH |
4209 | */ |
4210 | page = pte_page(entry); | |
4211 | if (page != pagecache_page) | |
0f792cf9 NH |
4212 | if (!trylock_page(page)) { |
4213 | need_wait_lock = 1; | |
4214 | goto out_ptl; | |
4215 | } | |
b4d1d99f | 4216 | |
0f792cf9 | 4217 | get_page(page); |
b4d1d99f | 4218 | |
788c7df4 | 4219 | if (flags & FAULT_FLAG_WRITE) { |
106c992a | 4220 | if (!huge_pte_write(entry)) { |
974e6d66 | 4221 | ret = hugetlb_cow(mm, vma, address, ptep, |
3999f52e | 4222 | pagecache_page, ptl); |
0f792cf9 | 4223 | goto out_put_page; |
b4d1d99f | 4224 | } |
106c992a | 4225 | entry = huge_pte_mkdirty(entry); |
b4d1d99f DG |
4226 | } |
4227 | entry = pte_mkyoung(entry); | |
285b8dca | 4228 | if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, |
788c7df4 | 4229 | flags & FAULT_FLAG_WRITE)) |
285b8dca | 4230 | update_mmu_cache(vma, haddr, ptep); |
0f792cf9 NH |
4231 | out_put_page: |
4232 | if (page != pagecache_page) | |
4233 | unlock_page(page); | |
4234 | put_page(page); | |
cb900f41 KS |
4235 | out_ptl: |
4236 | spin_unlock(ptl); | |
57303d80 AW |
4237 | |
4238 | if (pagecache_page) { | |
4239 | unlock_page(pagecache_page); | |
4240 | put_page(pagecache_page); | |
4241 | } | |
b4d1d99f | 4242 | out_mutex: |
c672c7f2 | 4243 | mutex_unlock(&hugetlb_fault_mutex_table[hash]); |
0f792cf9 NH |
4244 | /* |
4245 | * Generally it's safe to hold refcount during waiting page lock. But | |
4246 | * here we just wait to defer the next page fault to avoid busy loop and | |
4247 | * the page is not used after unlocked before returning from the current | |
4248 | * page fault. So we are safe from accessing freed page, even if we wait | |
4249 | * here without taking refcount. | |
4250 | */ | |
4251 | if (need_wait_lock) | |
4252 | wait_on_page_locked(page); | |
1e8f889b | 4253 | return ret; |
86e5216f AL |
4254 | } |
4255 | ||
8fb5debc MK |
4256 | /* |
4257 | * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with | |
4258 | * modifications for huge pages. | |
4259 | */ | |
4260 | int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, | |
4261 | pte_t *dst_pte, | |
4262 | struct vm_area_struct *dst_vma, | |
4263 | unsigned long dst_addr, | |
4264 | unsigned long src_addr, | |
4265 | struct page **pagep) | |
4266 | { | |
1e392147 AA |
4267 | struct address_space *mapping; |
4268 | pgoff_t idx; | |
4269 | unsigned long size; | |
1c9e8def | 4270 | int vm_shared = dst_vma->vm_flags & VM_SHARED; |
8fb5debc MK |
4271 | struct hstate *h = hstate_vma(dst_vma); |
4272 | pte_t _dst_pte; | |
4273 | spinlock_t *ptl; | |
4274 | int ret; | |
4275 | struct page *page; | |
4276 | ||
4277 | if (!*pagep) { | |
4278 | ret = -ENOMEM; | |
4279 | page = alloc_huge_page(dst_vma, dst_addr, 0); | |
4280 | if (IS_ERR(page)) | |
4281 | goto out; | |
4282 | ||
4283 | ret = copy_huge_page_from_user(page, | |
4284 | (const void __user *) src_addr, | |
810a56b9 | 4285 | pages_per_huge_page(h), false); |
8fb5debc MK |
4286 | |
4287 | /* fallback to copy_from_user outside mmap_sem */ | |
4288 | if (unlikely(ret)) { | |
9e368259 | 4289 | ret = -ENOENT; |
8fb5debc MK |
4290 | *pagep = page; |
4291 | /* don't free the page */ | |
4292 | goto out; | |
4293 | } | |
4294 | } else { | |
4295 | page = *pagep; | |
4296 | *pagep = NULL; | |
4297 | } | |
4298 | ||
4299 | /* | |
4300 | * The memory barrier inside __SetPageUptodate makes sure that | |
4301 | * preceding stores to the page contents become visible before | |
4302 | * the set_pte_at() write. | |
4303 | */ | |
4304 | __SetPageUptodate(page); | |
8fb5debc | 4305 | |
1e392147 AA |
4306 | mapping = dst_vma->vm_file->f_mapping; |
4307 | idx = vma_hugecache_offset(h, dst_vma, dst_addr); | |
4308 | ||
1c9e8def MK |
4309 | /* |
4310 | * If shared, add to page cache | |
4311 | */ | |
4312 | if (vm_shared) { | |
1e392147 AA |
4313 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4314 | ret = -EFAULT; | |
4315 | if (idx >= size) | |
4316 | goto out_release_nounlock; | |
1c9e8def | 4317 | |
1e392147 AA |
4318 | /* |
4319 | * Serialization between remove_inode_hugepages() and | |
4320 | * huge_add_to_page_cache() below happens through the | |
4321 | * hugetlb_fault_mutex_table that here must be hold by | |
4322 | * the caller. | |
4323 | */ | |
1c9e8def MK |
4324 | ret = huge_add_to_page_cache(page, mapping, idx); |
4325 | if (ret) | |
4326 | goto out_release_nounlock; | |
4327 | } | |
4328 | ||
8fb5debc MK |
4329 | ptl = huge_pte_lockptr(h, dst_mm, dst_pte); |
4330 | spin_lock(ptl); | |
4331 | ||
1e392147 AA |
4332 | /* |
4333 | * Recheck the i_size after holding PT lock to make sure not | |
4334 | * to leave any page mapped (as page_mapped()) beyond the end | |
4335 | * of the i_size (remove_inode_hugepages() is strict about | |
4336 | * enforcing that). If we bail out here, we'll also leave a | |
4337 | * page in the radix tree in the vm_shared case beyond the end | |
4338 | * of the i_size, but remove_inode_hugepages() will take care | |
4339 | * of it as soon as we drop the hugetlb_fault_mutex_table. | |
4340 | */ | |
4341 | size = i_size_read(mapping->host) >> huge_page_shift(h); | |
4342 | ret = -EFAULT; | |
4343 | if (idx >= size) | |
4344 | goto out_release_unlock; | |
4345 | ||
8fb5debc MK |
4346 | ret = -EEXIST; |
4347 | if (!huge_pte_none(huge_ptep_get(dst_pte))) | |
4348 | goto out_release_unlock; | |
4349 | ||
1c9e8def MK |
4350 | if (vm_shared) { |
4351 | page_dup_rmap(page, true); | |
4352 | } else { | |
4353 | ClearPagePrivate(page); | |
4354 | hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); | |
4355 | } | |
8fb5debc MK |
4356 | |
4357 | _dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE); | |
4358 | if (dst_vma->vm_flags & VM_WRITE) | |
4359 | _dst_pte = huge_pte_mkdirty(_dst_pte); | |
4360 | _dst_pte = pte_mkyoung(_dst_pte); | |
4361 | ||
4362 | set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); | |
4363 | ||
4364 | (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, | |
4365 | dst_vma->vm_flags & VM_WRITE); | |
4366 | hugetlb_count_add(pages_per_huge_page(h), dst_mm); | |
4367 | ||
4368 | /* No need to invalidate - it was non-present before */ | |
4369 | update_mmu_cache(dst_vma, dst_addr, dst_pte); | |
4370 | ||
4371 | spin_unlock(ptl); | |
cb6acd01 | 4372 | set_page_huge_active(page); |
1c9e8def MK |
4373 | if (vm_shared) |
4374 | unlock_page(page); | |
8fb5debc MK |
4375 | ret = 0; |
4376 | out: | |
4377 | return ret; | |
4378 | out_release_unlock: | |
4379 | spin_unlock(ptl); | |
1c9e8def MK |
4380 | if (vm_shared) |
4381 | unlock_page(page); | |
5af10dfd | 4382 | out_release_nounlock: |
8fb5debc MK |
4383 | put_page(page); |
4384 | goto out; | |
4385 | } | |
4386 | ||
28a35716 ML |
4387 | long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
4388 | struct page **pages, struct vm_area_struct **vmas, | |
4389 | unsigned long *position, unsigned long *nr_pages, | |
87ffc118 | 4390 | long i, unsigned int flags, int *nonblocking) |
63551ae0 | 4391 | { |
d5d4b0aa KC |
4392 | unsigned long pfn_offset; |
4393 | unsigned long vaddr = *position; | |
28a35716 | 4394 | unsigned long remainder = *nr_pages; |
a5516438 | 4395 | struct hstate *h = hstate_vma(vma); |
2be7cfed | 4396 | int err = -EFAULT; |
63551ae0 | 4397 | |
63551ae0 | 4398 | while (vaddr < vma->vm_end && remainder) { |
4c887265 | 4399 | pte_t *pte; |
cb900f41 | 4400 | spinlock_t *ptl = NULL; |
2a15efc9 | 4401 | int absent; |
4c887265 | 4402 | struct page *page; |
63551ae0 | 4403 | |
02057967 DR |
4404 | /* |
4405 | * If we have a pending SIGKILL, don't keep faulting pages and | |
4406 | * potentially allocating memory. | |
4407 | */ | |
fa45f116 | 4408 | if (fatal_signal_pending(current)) { |
02057967 DR |
4409 | remainder = 0; |
4410 | break; | |
4411 | } | |
4412 | ||
4c887265 AL |
4413 | /* |
4414 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2a15efc9 | 4415 | * each hugepage. We have to make sure we get the |
4c887265 | 4416 | * first, for the page indexing below to work. |
cb900f41 KS |
4417 | * |
4418 | * Note that page table lock is not held when pte is null. | |
4c887265 | 4419 | */ |
7868a208 PA |
4420 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), |
4421 | huge_page_size(h)); | |
cb900f41 KS |
4422 | if (pte) |
4423 | ptl = huge_pte_lock(h, mm, pte); | |
2a15efc9 HD |
4424 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
4425 | ||
4426 | /* | |
4427 | * When coredumping, it suits get_dump_page if we just return | |
3ae77f43 HD |
4428 | * an error where there's an empty slot with no huge pagecache |
4429 | * to back it. This way, we avoid allocating a hugepage, and | |
4430 | * the sparse dumpfile avoids allocating disk blocks, but its | |
4431 | * huge holes still show up with zeroes where they need to be. | |
2a15efc9 | 4432 | */ |
3ae77f43 HD |
4433 | if (absent && (flags & FOLL_DUMP) && |
4434 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { | |
cb900f41 KS |
4435 | if (pte) |
4436 | spin_unlock(ptl); | |
2a15efc9 HD |
4437 | remainder = 0; |
4438 | break; | |
4439 | } | |
63551ae0 | 4440 | |
9cc3a5bd NH |
4441 | /* |
4442 | * We need call hugetlb_fault for both hugepages under migration | |
4443 | * (in which case hugetlb_fault waits for the migration,) and | |
4444 | * hwpoisoned hugepages (in which case we need to prevent the | |
4445 | * caller from accessing to them.) In order to do this, we use | |
4446 | * here is_swap_pte instead of is_hugetlb_entry_migration and | |
4447 | * is_hugetlb_entry_hwpoisoned. This is because it simply covers | |
4448 | * both cases, and because we can't follow correct pages | |
4449 | * directly from any kind of swap entries. | |
4450 | */ | |
4451 | if (absent || is_swap_pte(huge_ptep_get(pte)) || | |
106c992a GS |
4452 | ((flags & FOLL_WRITE) && |
4453 | !huge_pte_write(huge_ptep_get(pte)))) { | |
2b740303 | 4454 | vm_fault_t ret; |
87ffc118 | 4455 | unsigned int fault_flags = 0; |
63551ae0 | 4456 | |
cb900f41 KS |
4457 | if (pte) |
4458 | spin_unlock(ptl); | |
87ffc118 AA |
4459 | if (flags & FOLL_WRITE) |
4460 | fault_flags |= FAULT_FLAG_WRITE; | |
4461 | if (nonblocking) | |
4462 | fault_flags |= FAULT_FLAG_ALLOW_RETRY; | |
4463 | if (flags & FOLL_NOWAIT) | |
4464 | fault_flags |= FAULT_FLAG_ALLOW_RETRY | | |
4465 | FAULT_FLAG_RETRY_NOWAIT; | |
4466 | if (flags & FOLL_TRIED) { | |
4467 | VM_WARN_ON_ONCE(fault_flags & | |
4468 | FAULT_FLAG_ALLOW_RETRY); | |
4469 | fault_flags |= FAULT_FLAG_TRIED; | |
4470 | } | |
4471 | ret = hugetlb_fault(mm, vma, vaddr, fault_flags); | |
4472 | if (ret & VM_FAULT_ERROR) { | |
2be7cfed | 4473 | err = vm_fault_to_errno(ret, flags); |
87ffc118 AA |
4474 | remainder = 0; |
4475 | break; | |
4476 | } | |
4477 | if (ret & VM_FAULT_RETRY) { | |
1ac25013 AA |
4478 | if (nonblocking && |
4479 | !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) | |
87ffc118 AA |
4480 | *nonblocking = 0; |
4481 | *nr_pages = 0; | |
4482 | /* | |
4483 | * VM_FAULT_RETRY must not return an | |
4484 | * error, it will return zero | |
4485 | * instead. | |
4486 | * | |
4487 | * No need to update "position" as the | |
4488 | * caller will not check it after | |
4489 | * *nr_pages is set to 0. | |
4490 | */ | |
4491 | return i; | |
4492 | } | |
4493 | continue; | |
4c887265 AL |
4494 | } |
4495 | ||
a5516438 | 4496 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 4497 | page = pte_page(huge_ptep_get(pte)); |
8fde12ca LT |
4498 | |
4499 | /* | |
4500 | * Instead of doing 'try_get_page()' below in the same_page | |
4501 | * loop, just check the count once here. | |
4502 | */ | |
4503 | if (unlikely(page_count(page) <= 0)) { | |
4504 | if (pages) { | |
4505 | spin_unlock(ptl); | |
4506 | remainder = 0; | |
4507 | err = -ENOMEM; | |
4508 | break; | |
4509 | } | |
4510 | } | |
d5d4b0aa | 4511 | same_page: |
d6692183 | 4512 | if (pages) { |
2a15efc9 | 4513 | pages[i] = mem_map_offset(page, pfn_offset); |
ddc58f27 | 4514 | get_page(pages[i]); |
d6692183 | 4515 | } |
63551ae0 DG |
4516 | |
4517 | if (vmas) | |
4518 | vmas[i] = vma; | |
4519 | ||
4520 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 4521 | ++pfn_offset; |
63551ae0 DG |
4522 | --remainder; |
4523 | ++i; | |
d5d4b0aa | 4524 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 4525 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa KC |
4526 | /* |
4527 | * We use pfn_offset to avoid touching the pageframes | |
4528 | * of this compound page. | |
4529 | */ | |
4530 | goto same_page; | |
4531 | } | |
cb900f41 | 4532 | spin_unlock(ptl); |
63551ae0 | 4533 | } |
28a35716 | 4534 | *nr_pages = remainder; |
87ffc118 AA |
4535 | /* |
4536 | * setting position is actually required only if remainder is | |
4537 | * not zero but it's faster not to add a "if (remainder)" | |
4538 | * branch. | |
4539 | */ | |
63551ae0 DG |
4540 | *position = vaddr; |
4541 | ||
2be7cfed | 4542 | return i ? i : err; |
63551ae0 | 4543 | } |
8f860591 | 4544 | |
5491ae7b AK |
4545 | #ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE |
4546 | /* | |
4547 | * ARCHes with special requirements for evicting HUGETLB backing TLB entries can | |
4548 | * implement this. | |
4549 | */ | |
4550 | #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) | |
4551 | #endif | |
4552 | ||
7da4d641 | 4553 | unsigned long hugetlb_change_protection(struct vm_area_struct *vma, |
8f860591 ZY |
4554 | unsigned long address, unsigned long end, pgprot_t newprot) |
4555 | { | |
4556 | struct mm_struct *mm = vma->vm_mm; | |
4557 | unsigned long start = address; | |
4558 | pte_t *ptep; | |
4559 | pte_t pte; | |
a5516438 | 4560 | struct hstate *h = hstate_vma(vma); |
7da4d641 | 4561 | unsigned long pages = 0; |
dff11abe | 4562 | bool shared_pmd = false; |
ac46d4f3 | 4563 | struct mmu_notifier_range range; |
dff11abe MK |
4564 | |
4565 | /* | |
4566 | * In the case of shared PMDs, the area to flush could be beyond | |
ac46d4f3 | 4567 | * start/end. Set range.start/range.end to cover the maximum possible |
dff11abe MK |
4568 | * range if PMD sharing is possible. |
4569 | */ | |
7269f999 JG |
4570 | mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, |
4571 | 0, vma, mm, start, end); | |
ac46d4f3 | 4572 | adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); |
8f860591 ZY |
4573 | |
4574 | BUG_ON(address >= end); | |
ac46d4f3 | 4575 | flush_cache_range(vma, range.start, range.end); |
8f860591 | 4576 | |
ac46d4f3 | 4577 | mmu_notifier_invalidate_range_start(&range); |
83cde9e8 | 4578 | i_mmap_lock_write(vma->vm_file->f_mapping); |
a5516438 | 4579 | for (; address < end; address += huge_page_size(h)) { |
cb900f41 | 4580 | spinlock_t *ptl; |
7868a208 | 4581 | ptep = huge_pte_offset(mm, address, huge_page_size(h)); |
8f860591 ZY |
4582 | if (!ptep) |
4583 | continue; | |
cb900f41 | 4584 | ptl = huge_pte_lock(h, mm, ptep); |
7da4d641 PZ |
4585 | if (huge_pmd_unshare(mm, &address, ptep)) { |
4586 | pages++; | |
cb900f41 | 4587 | spin_unlock(ptl); |
dff11abe | 4588 | shared_pmd = true; |
39dde65c | 4589 | continue; |
7da4d641 | 4590 | } |
a8bda28d NH |
4591 | pte = huge_ptep_get(ptep); |
4592 | if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { | |
4593 | spin_unlock(ptl); | |
4594 | continue; | |
4595 | } | |
4596 | if (unlikely(is_hugetlb_entry_migration(pte))) { | |
4597 | swp_entry_t entry = pte_to_swp_entry(pte); | |
4598 | ||
4599 | if (is_write_migration_entry(entry)) { | |
4600 | pte_t newpte; | |
4601 | ||
4602 | make_migration_entry_read(&entry); | |
4603 | newpte = swp_entry_to_pte(entry); | |
e5251fd4 PA |
4604 | set_huge_swap_pte_at(mm, address, ptep, |
4605 | newpte, huge_page_size(h)); | |
a8bda28d NH |
4606 | pages++; |
4607 | } | |
4608 | spin_unlock(ptl); | |
4609 | continue; | |
4610 | } | |
4611 | if (!huge_pte_none(pte)) { | |
023bdd00 AK |
4612 | pte_t old_pte; |
4613 | ||
4614 | old_pte = huge_ptep_modify_prot_start(vma, address, ptep); | |
4615 | pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); | |
be7517d6 | 4616 | pte = arch_make_huge_pte(pte, vma, NULL, 0); |
023bdd00 | 4617 | huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); |
7da4d641 | 4618 | pages++; |
8f860591 | 4619 | } |
cb900f41 | 4620 | spin_unlock(ptl); |
8f860591 | 4621 | } |
d833352a | 4622 | /* |
c8c06efa | 4623 | * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare |
d833352a | 4624 | * may have cleared our pud entry and done put_page on the page table: |
c8c06efa | 4625 | * once we release i_mmap_rwsem, another task can do the final put_page |
dff11abe MK |
4626 | * and that page table be reused and filled with junk. If we actually |
4627 | * did unshare a page of pmds, flush the range corresponding to the pud. | |
d833352a | 4628 | */ |
dff11abe | 4629 | if (shared_pmd) |
ac46d4f3 | 4630 | flush_hugetlb_tlb_range(vma, range.start, range.end); |
dff11abe MK |
4631 | else |
4632 | flush_hugetlb_tlb_range(vma, start, end); | |
0f10851e JG |
4633 | /* |
4634 | * No need to call mmu_notifier_invalidate_range() we are downgrading | |
4635 | * page table protection not changing it to point to a new page. | |
4636 | * | |
ad56b738 | 4637 | * See Documentation/vm/mmu_notifier.rst |
0f10851e | 4638 | */ |
83cde9e8 | 4639 | i_mmap_unlock_write(vma->vm_file->f_mapping); |
ac46d4f3 | 4640 | mmu_notifier_invalidate_range_end(&range); |
7da4d641 PZ |
4641 | |
4642 | return pages << h->order; | |
8f860591 ZY |
4643 | } |
4644 | ||
a1e78772 MG |
4645 | int hugetlb_reserve_pages(struct inode *inode, |
4646 | long from, long to, | |
5a6fe125 | 4647 | struct vm_area_struct *vma, |
ca16d140 | 4648 | vm_flags_t vm_flags) |
e4e574b7 | 4649 | { |
17c9d12e | 4650 | long ret, chg; |
a5516438 | 4651 | struct hstate *h = hstate_inode(inode); |
90481622 | 4652 | struct hugepage_subpool *spool = subpool_inode(inode); |
9119a41e | 4653 | struct resv_map *resv_map; |
1c5ecae3 | 4654 | long gbl_reserve; |
e4e574b7 | 4655 | |
63489f8e MK |
4656 | /* This should never happen */ |
4657 | if (from > to) { | |
4658 | VM_WARN(1, "%s called with a negative range\n", __func__); | |
4659 | return -EINVAL; | |
4660 | } | |
4661 | ||
17c9d12e MG |
4662 | /* |
4663 | * Only apply hugepage reservation if asked. At fault time, an | |
4664 | * attempt will be made for VM_NORESERVE to allocate a page | |
90481622 | 4665 | * without using reserves |
17c9d12e | 4666 | */ |
ca16d140 | 4667 | if (vm_flags & VM_NORESERVE) |
17c9d12e MG |
4668 | return 0; |
4669 | ||
a1e78772 MG |
4670 | /* |
4671 | * Shared mappings base their reservation on the number of pages that | |
4672 | * are already allocated on behalf of the file. Private mappings need | |
4673 | * to reserve the full area even if read-only as mprotect() may be | |
4674 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
4675 | */ | |
9119a41e | 4676 | if (!vma || vma->vm_flags & VM_MAYSHARE) { |
f27a5136 MK |
4677 | /* |
4678 | * resv_map can not be NULL as hugetlb_reserve_pages is only | |
4679 | * called for inodes for which resv_maps were created (see | |
4680 | * hugetlbfs_get_inode). | |
4681 | */ | |
4e35f483 | 4682 | resv_map = inode_resv_map(inode); |
9119a41e | 4683 | |
1406ec9b | 4684 | chg = region_chg(resv_map, from, to); |
9119a41e JK |
4685 | |
4686 | } else { | |
4687 | resv_map = resv_map_alloc(); | |
17c9d12e MG |
4688 | if (!resv_map) |
4689 | return -ENOMEM; | |
4690 | ||
a1e78772 | 4691 | chg = to - from; |
84afd99b | 4692 | |
17c9d12e MG |
4693 | set_vma_resv_map(vma, resv_map); |
4694 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
4695 | } | |
4696 | ||
c50ac050 DH |
4697 | if (chg < 0) { |
4698 | ret = chg; | |
4699 | goto out_err; | |
4700 | } | |
8a630112 | 4701 | |
1c5ecae3 MK |
4702 | /* |
4703 | * There must be enough pages in the subpool for the mapping. If | |
4704 | * the subpool has a minimum size, there may be some global | |
4705 | * reservations already in place (gbl_reserve). | |
4706 | */ | |
4707 | gbl_reserve = hugepage_subpool_get_pages(spool, chg); | |
4708 | if (gbl_reserve < 0) { | |
c50ac050 DH |
4709 | ret = -ENOSPC; |
4710 | goto out_err; | |
4711 | } | |
5a6fe125 MG |
4712 | |
4713 | /* | |
17c9d12e | 4714 | * Check enough hugepages are available for the reservation. |
90481622 | 4715 | * Hand the pages back to the subpool if there are not |
5a6fe125 | 4716 | */ |
1c5ecae3 | 4717 | ret = hugetlb_acct_memory(h, gbl_reserve); |
68842c9b | 4718 | if (ret < 0) { |
1c5ecae3 MK |
4719 | /* put back original number of pages, chg */ |
4720 | (void)hugepage_subpool_put_pages(spool, chg); | |
c50ac050 | 4721 | goto out_err; |
68842c9b | 4722 | } |
17c9d12e MG |
4723 | |
4724 | /* | |
4725 | * Account for the reservations made. Shared mappings record regions | |
4726 | * that have reservations as they are shared by multiple VMAs. | |
4727 | * When the last VMA disappears, the region map says how much | |
4728 | * the reservation was and the page cache tells how much of | |
4729 | * the reservation was consumed. Private mappings are per-VMA and | |
4730 | * only the consumed reservations are tracked. When the VMA | |
4731 | * disappears, the original reservation is the VMA size and the | |
4732 | * consumed reservations are stored in the map. Hence, nothing | |
4733 | * else has to be done for private mappings here | |
4734 | */ | |
33039678 MK |
4735 | if (!vma || vma->vm_flags & VM_MAYSHARE) { |
4736 | long add = region_add(resv_map, from, to); | |
4737 | ||
4738 | if (unlikely(chg > add)) { | |
4739 | /* | |
4740 | * pages in this range were added to the reserve | |
4741 | * map between region_chg and region_add. This | |
4742 | * indicates a race with alloc_huge_page. Adjust | |
4743 | * the subpool and reserve counts modified above | |
4744 | * based on the difference. | |
4745 | */ | |
4746 | long rsv_adjust; | |
4747 | ||
4748 | rsv_adjust = hugepage_subpool_put_pages(spool, | |
4749 | chg - add); | |
4750 | hugetlb_acct_memory(h, -rsv_adjust); | |
4751 | } | |
4752 | } | |
a43a8c39 | 4753 | return 0; |
c50ac050 | 4754 | out_err: |
5e911373 | 4755 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
ff8c0c53 MK |
4756 | /* Don't call region_abort if region_chg failed */ |
4757 | if (chg >= 0) | |
4758 | region_abort(resv_map, from, to); | |
f031dd27 JK |
4759 | if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
4760 | kref_put(&resv_map->refs, resv_map_release); | |
c50ac050 | 4761 | return ret; |
a43a8c39 KC |
4762 | } |
4763 | ||
b5cec28d MK |
4764 | long hugetlb_unreserve_pages(struct inode *inode, long start, long end, |
4765 | long freed) | |
a43a8c39 | 4766 | { |
a5516438 | 4767 | struct hstate *h = hstate_inode(inode); |
4e35f483 | 4768 | struct resv_map *resv_map = inode_resv_map(inode); |
9119a41e | 4769 | long chg = 0; |
90481622 | 4770 | struct hugepage_subpool *spool = subpool_inode(inode); |
1c5ecae3 | 4771 | long gbl_reserve; |
45c682a6 | 4772 | |
f27a5136 MK |
4773 | /* |
4774 | * Since this routine can be called in the evict inode path for all | |
4775 | * hugetlbfs inodes, resv_map could be NULL. | |
4776 | */ | |
b5cec28d MK |
4777 | if (resv_map) { |
4778 | chg = region_del(resv_map, start, end); | |
4779 | /* | |
4780 | * region_del() can fail in the rare case where a region | |
4781 | * must be split and another region descriptor can not be | |
4782 | * allocated. If end == LONG_MAX, it will not fail. | |
4783 | */ | |
4784 | if (chg < 0) | |
4785 | return chg; | |
4786 | } | |
4787 | ||
45c682a6 | 4788 | spin_lock(&inode->i_lock); |
e4c6f8be | 4789 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
4790 | spin_unlock(&inode->i_lock); |
4791 | ||
1c5ecae3 MK |
4792 | /* |
4793 | * If the subpool has a minimum size, the number of global | |
4794 | * reservations to be released may be adjusted. | |
4795 | */ | |
4796 | gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); | |
4797 | hugetlb_acct_memory(h, -gbl_reserve); | |
b5cec28d MK |
4798 | |
4799 | return 0; | |
a43a8c39 | 4800 | } |
93f70f90 | 4801 | |
3212b535 SC |
4802 | #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE |
4803 | static unsigned long page_table_shareable(struct vm_area_struct *svma, | |
4804 | struct vm_area_struct *vma, | |
4805 | unsigned long addr, pgoff_t idx) | |
4806 | { | |
4807 | unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + | |
4808 | svma->vm_start; | |
4809 | unsigned long sbase = saddr & PUD_MASK; | |
4810 | unsigned long s_end = sbase + PUD_SIZE; | |
4811 | ||
4812 | /* Allow segments to share if only one is marked locked */ | |
de60f5f1 EM |
4813 | unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; |
4814 | unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; | |
3212b535 SC |
4815 | |
4816 | /* | |
4817 | * match the virtual addresses, permission and the alignment of the | |
4818 | * page table page. | |
4819 | */ | |
4820 | if (pmd_index(addr) != pmd_index(saddr) || | |
4821 | vm_flags != svm_flags || | |
4822 | sbase < svma->vm_start || svma->vm_end < s_end) | |
4823 | return 0; | |
4824 | ||
4825 | return saddr; | |
4826 | } | |
4827 | ||
31aafb45 | 4828 | static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) |
3212b535 SC |
4829 | { |
4830 | unsigned long base = addr & PUD_MASK; | |
4831 | unsigned long end = base + PUD_SIZE; | |
4832 | ||
4833 | /* | |
4834 | * check on proper vm_flags and page table alignment | |
4835 | */ | |
017b1660 | 4836 | if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) |
31aafb45 NK |
4837 | return true; |
4838 | return false; | |
3212b535 SC |
4839 | } |
4840 | ||
017b1660 MK |
4841 | /* |
4842 | * Determine if start,end range within vma could be mapped by shared pmd. | |
4843 | * If yes, adjust start and end to cover range associated with possible | |
4844 | * shared pmd mappings. | |
4845 | */ | |
4846 | void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, | |
4847 | unsigned long *start, unsigned long *end) | |
4848 | { | |
4849 | unsigned long check_addr = *start; | |
4850 | ||
4851 | if (!(vma->vm_flags & VM_MAYSHARE)) | |
4852 | return; | |
4853 | ||
4854 | for (check_addr = *start; check_addr < *end; check_addr += PUD_SIZE) { | |
4855 | unsigned long a_start = check_addr & PUD_MASK; | |
4856 | unsigned long a_end = a_start + PUD_SIZE; | |
4857 | ||
4858 | /* | |
4859 | * If sharing is possible, adjust start/end if necessary. | |
4860 | */ | |
4861 | if (range_in_vma(vma, a_start, a_end)) { | |
4862 | if (a_start < *start) | |
4863 | *start = a_start; | |
4864 | if (a_end > *end) | |
4865 | *end = a_end; | |
4866 | } | |
4867 | } | |
4868 | } | |
4869 | ||
3212b535 SC |
4870 | /* |
4871 | * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() | |
4872 | * and returns the corresponding pte. While this is not necessary for the | |
4873 | * !shared pmd case because we can allocate the pmd later as well, it makes the | |
ddeaab32 MK |
4874 | * code much cleaner. pmd allocation is essential for the shared case because |
4875 | * pud has to be populated inside the same i_mmap_rwsem section - otherwise | |
4876 | * racing tasks could either miss the sharing (see huge_pte_offset) or select a | |
4877 | * bad pmd for sharing. | |
3212b535 SC |
4878 | */ |
4879 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
4880 | { | |
4881 | struct vm_area_struct *vma = find_vma(mm, addr); | |
4882 | struct address_space *mapping = vma->vm_file->f_mapping; | |
4883 | pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + | |
4884 | vma->vm_pgoff; | |
4885 | struct vm_area_struct *svma; | |
4886 | unsigned long saddr; | |
4887 | pte_t *spte = NULL; | |
4888 | pte_t *pte; | |
cb900f41 | 4889 | spinlock_t *ptl; |
3212b535 SC |
4890 | |
4891 | if (!vma_shareable(vma, addr)) | |
4892 | return (pte_t *)pmd_alloc(mm, pud, addr); | |
4893 | ||
6f21bb93 | 4894 | i_mmap_lock_read(mapping); |
3212b535 SC |
4895 | vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { |
4896 | if (svma == vma) | |
4897 | continue; | |
4898 | ||
4899 | saddr = page_table_shareable(svma, vma, addr, idx); | |
4900 | if (saddr) { | |
7868a208 PA |
4901 | spte = huge_pte_offset(svma->vm_mm, saddr, |
4902 | vma_mmu_pagesize(svma)); | |
3212b535 SC |
4903 | if (spte) { |
4904 | get_page(virt_to_page(spte)); | |
4905 | break; | |
4906 | } | |
4907 | } | |
4908 | } | |
4909 | ||
4910 | if (!spte) | |
4911 | goto out; | |
4912 | ||
8bea8052 | 4913 | ptl = huge_pte_lock(hstate_vma(vma), mm, spte); |
dc6c9a35 | 4914 | if (pud_none(*pud)) { |
3212b535 SC |
4915 | pud_populate(mm, pud, |
4916 | (pmd_t *)((unsigned long)spte & PAGE_MASK)); | |
c17b1f42 | 4917 | mm_inc_nr_pmds(mm); |
dc6c9a35 | 4918 | } else { |
3212b535 | 4919 | put_page(virt_to_page(spte)); |
dc6c9a35 | 4920 | } |
cb900f41 | 4921 | spin_unlock(ptl); |
3212b535 SC |
4922 | out: |
4923 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
6f21bb93 | 4924 | i_mmap_unlock_read(mapping); |
3212b535 SC |
4925 | return pte; |
4926 | } | |
4927 | ||
4928 | /* | |
4929 | * unmap huge page backed by shared pte. | |
4930 | * | |
4931 | * Hugetlb pte page is ref counted at the time of mapping. If pte is shared | |
4932 | * indicated by page_count > 1, unmap is achieved by clearing pud and | |
4933 | * decrementing the ref count. If count == 1, the pte page is not shared. | |
4934 | * | |
ddeaab32 | 4935 | * called with page table lock held. |
3212b535 SC |
4936 | * |
4937 | * returns: 1 successfully unmapped a shared pte page | |
4938 | * 0 the underlying pte page is not shared, or it is the last user | |
4939 | */ | |
4940 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
4941 | { | |
4942 | pgd_t *pgd = pgd_offset(mm, *addr); | |
c2febafc KS |
4943 | p4d_t *p4d = p4d_offset(pgd, *addr); |
4944 | pud_t *pud = pud_offset(p4d, *addr); | |
3212b535 SC |
4945 | |
4946 | BUG_ON(page_count(virt_to_page(ptep)) == 0); | |
4947 | if (page_count(virt_to_page(ptep)) == 1) | |
4948 | return 0; | |
4949 | ||
4950 | pud_clear(pud); | |
4951 | put_page(virt_to_page(ptep)); | |
dc6c9a35 | 4952 | mm_dec_nr_pmds(mm); |
3212b535 SC |
4953 | *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; |
4954 | return 1; | |
4955 | } | |
9e5fc74c SC |
4956 | #define want_pmd_share() (1) |
4957 | #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ | |
4958 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
4959 | { | |
4960 | return NULL; | |
4961 | } | |
e81f2d22 ZZ |
4962 | |
4963 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
4964 | { | |
4965 | return 0; | |
4966 | } | |
017b1660 MK |
4967 | |
4968 | void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, | |
4969 | unsigned long *start, unsigned long *end) | |
4970 | { | |
4971 | } | |
9e5fc74c | 4972 | #define want_pmd_share() (0) |
3212b535 SC |
4973 | #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ |
4974 | ||
9e5fc74c SC |
4975 | #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB |
4976 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
4977 | unsigned long addr, unsigned long sz) | |
4978 | { | |
4979 | pgd_t *pgd; | |
c2febafc | 4980 | p4d_t *p4d; |
9e5fc74c SC |
4981 | pud_t *pud; |
4982 | pte_t *pte = NULL; | |
4983 | ||
4984 | pgd = pgd_offset(mm, addr); | |
f4f0a3d8 KS |
4985 | p4d = p4d_alloc(mm, pgd, addr); |
4986 | if (!p4d) | |
4987 | return NULL; | |
c2febafc | 4988 | pud = pud_alloc(mm, p4d, addr); |
9e5fc74c SC |
4989 | if (pud) { |
4990 | if (sz == PUD_SIZE) { | |
4991 | pte = (pte_t *)pud; | |
4992 | } else { | |
4993 | BUG_ON(sz != PMD_SIZE); | |
4994 | if (want_pmd_share() && pud_none(*pud)) | |
4995 | pte = huge_pmd_share(mm, addr, pud); | |
4996 | else | |
4997 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
4998 | } | |
4999 | } | |
4e666314 | 5000 | BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); |
9e5fc74c SC |
5001 | |
5002 | return pte; | |
5003 | } | |
5004 | ||
9b19df29 PA |
5005 | /* |
5006 | * huge_pte_offset() - Walk the page table to resolve the hugepage | |
5007 | * entry at address @addr | |
5008 | * | |
5009 | * Return: Pointer to page table or swap entry (PUD or PMD) for | |
5010 | * address @addr, or NULL if a p*d_none() entry is encountered and the | |
5011 | * size @sz doesn't match the hugepage size at this level of the page | |
5012 | * table. | |
5013 | */ | |
7868a208 PA |
5014 | pte_t *huge_pte_offset(struct mm_struct *mm, |
5015 | unsigned long addr, unsigned long sz) | |
9e5fc74c SC |
5016 | { |
5017 | pgd_t *pgd; | |
c2febafc | 5018 | p4d_t *p4d; |
37a6e55e L |
5019 | pud_t *pud, pud_entry; |
5020 | pmd_t *pmd, pmd_entry; | |
9e5fc74c SC |
5021 | |
5022 | pgd = pgd_offset(mm, addr); | |
c2febafc KS |
5023 | if (!pgd_present(*pgd)) |
5024 | return NULL; | |
5025 | p4d = p4d_offset(pgd, addr); | |
5026 | if (!p4d_present(*p4d)) | |
5027 | return NULL; | |
9b19df29 | 5028 | |
c2febafc | 5029 | pud = pud_offset(p4d, addr); |
37a6e55e L |
5030 | pud_entry = READ_ONCE(*pud); |
5031 | if (sz != PUD_SIZE && pud_none(pud_entry)) | |
c2febafc | 5032 | return NULL; |
9b19df29 | 5033 | /* hugepage or swap? */ |
37a6e55e | 5034 | if (pud_huge(pud_entry) || !pud_present(pud_entry)) |
c2febafc | 5035 | return (pte_t *)pud; |
9b19df29 | 5036 | |
c2febafc | 5037 | pmd = pmd_offset(pud, addr); |
37a6e55e L |
5038 | pmd_entry = READ_ONCE(*pmd); |
5039 | if (sz != PMD_SIZE && pmd_none(pmd_entry)) | |
9b19df29 PA |
5040 | return NULL; |
5041 | /* hugepage or swap? */ | |
37a6e55e | 5042 | if (pmd_huge(pmd_entry) || !pmd_present(pmd_entry)) |
9b19df29 PA |
5043 | return (pte_t *)pmd; |
5044 | ||
5045 | return NULL; | |
9e5fc74c SC |
5046 | } |
5047 | ||
61f77eda NH |
5048 | #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ |
5049 | ||
5050 | /* | |
5051 | * These functions are overwritable if your architecture needs its own | |
5052 | * behavior. | |
5053 | */ | |
5054 | struct page * __weak | |
5055 | follow_huge_addr(struct mm_struct *mm, unsigned long address, | |
5056 | int write) | |
5057 | { | |
5058 | return ERR_PTR(-EINVAL); | |
5059 | } | |
5060 | ||
4dc71451 AK |
5061 | struct page * __weak |
5062 | follow_huge_pd(struct vm_area_struct *vma, | |
5063 | unsigned long address, hugepd_t hpd, int flags, int pdshift) | |
5064 | { | |
5065 | WARN(1, "hugepd follow called with no support for hugepage directory format\n"); | |
5066 | return NULL; | |
5067 | } | |
5068 | ||
61f77eda | 5069 | struct page * __weak |
9e5fc74c | 5070 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, |
e66f17ff | 5071 | pmd_t *pmd, int flags) |
9e5fc74c | 5072 | { |
e66f17ff NH |
5073 | struct page *page = NULL; |
5074 | spinlock_t *ptl; | |
c9d398fa | 5075 | pte_t pte; |
e66f17ff NH |
5076 | retry: |
5077 | ptl = pmd_lockptr(mm, pmd); | |
5078 | spin_lock(ptl); | |
5079 | /* | |
5080 | * make sure that the address range covered by this pmd is not | |
5081 | * unmapped from other threads. | |
5082 | */ | |
5083 | if (!pmd_huge(*pmd)) | |
5084 | goto out; | |
c9d398fa NH |
5085 | pte = huge_ptep_get((pte_t *)pmd); |
5086 | if (pte_present(pte)) { | |
97534127 | 5087 | page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); |
e66f17ff NH |
5088 | if (flags & FOLL_GET) |
5089 | get_page(page); | |
5090 | } else { | |
c9d398fa | 5091 | if (is_hugetlb_entry_migration(pte)) { |
e66f17ff NH |
5092 | spin_unlock(ptl); |
5093 | __migration_entry_wait(mm, (pte_t *)pmd, ptl); | |
5094 | goto retry; | |
5095 | } | |
5096 | /* | |
5097 | * hwpoisoned entry is treated as no_page_table in | |
5098 | * follow_page_mask(). | |
5099 | */ | |
5100 | } | |
5101 | out: | |
5102 | spin_unlock(ptl); | |
9e5fc74c SC |
5103 | return page; |
5104 | } | |
5105 | ||
61f77eda | 5106 | struct page * __weak |
9e5fc74c | 5107 | follow_huge_pud(struct mm_struct *mm, unsigned long address, |
e66f17ff | 5108 | pud_t *pud, int flags) |
9e5fc74c | 5109 | { |
e66f17ff NH |
5110 | if (flags & FOLL_GET) |
5111 | return NULL; | |
9e5fc74c | 5112 | |
e66f17ff | 5113 | return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); |
9e5fc74c SC |
5114 | } |
5115 | ||
faaa5b62 AK |
5116 | struct page * __weak |
5117 | follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) | |
5118 | { | |
5119 | if (flags & FOLL_GET) | |
5120 | return NULL; | |
5121 | ||
5122 | return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); | |
5123 | } | |
5124 | ||
31caf665 NH |
5125 | bool isolate_huge_page(struct page *page, struct list_head *list) |
5126 | { | |
bcc54222 NH |
5127 | bool ret = true; |
5128 | ||
309381fe | 5129 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 | 5130 | spin_lock(&hugetlb_lock); |
bcc54222 NH |
5131 | if (!page_huge_active(page) || !get_page_unless_zero(page)) { |
5132 | ret = false; | |
5133 | goto unlock; | |
5134 | } | |
5135 | clear_page_huge_active(page); | |
31caf665 | 5136 | list_move_tail(&page->lru, list); |
bcc54222 | 5137 | unlock: |
31caf665 | 5138 | spin_unlock(&hugetlb_lock); |
bcc54222 | 5139 | return ret; |
31caf665 NH |
5140 | } |
5141 | ||
5142 | void putback_active_hugepage(struct page *page) | |
5143 | { | |
309381fe | 5144 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 | 5145 | spin_lock(&hugetlb_lock); |
bcc54222 | 5146 | set_page_huge_active(page); |
31caf665 NH |
5147 | list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); |
5148 | spin_unlock(&hugetlb_lock); | |
5149 | put_page(page); | |
5150 | } | |
ab5ac90a MH |
5151 | |
5152 | void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) | |
5153 | { | |
5154 | struct hstate *h = page_hstate(oldpage); | |
5155 | ||
5156 | hugetlb_cgroup_migrate(oldpage, newpage); | |
5157 | set_page_owner_migrate_reason(newpage, reason); | |
5158 | ||
5159 | /* | |
5160 | * transfer temporary state of the new huge page. This is | |
5161 | * reverse to other transitions because the newpage is going to | |
5162 | * be final while the old one will be freed so it takes over | |
5163 | * the temporary status. | |
5164 | * | |
5165 | * Also note that we have to transfer the per-node surplus state | |
5166 | * here as well otherwise the global surplus count will not match | |
5167 | * the per-node's. | |
5168 | */ | |
5169 | if (PageHugeTemporary(newpage)) { | |
5170 | int old_nid = page_to_nid(oldpage); | |
5171 | int new_nid = page_to_nid(newpage); | |
5172 | ||
5173 | SetPageHugeTemporary(oldpage); | |
5174 | ClearPageHugeTemporary(newpage); | |
5175 | ||
5176 | spin_lock(&hugetlb_lock); | |
5177 | if (h->surplus_huge_pages_node[old_nid]) { | |
5178 | h->surplus_huge_pages_node[old_nid]--; | |
5179 | h->surplus_huge_pages_node[new_nid]++; | |
5180 | } | |
5181 | spin_unlock(&hugetlb_lock); | |
5182 | } | |
5183 | } |