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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
6d49e352 | 3 | * (C) Nadia Yvette Chambers, April 2004 |
1da177e4 | 4 | */ |
1da177e4 LT |
5 | #include <linux/list.h> |
6 | #include <linux/init.h> | |
1da177e4 | 7 | #include <linux/mm.h> |
e1759c21 | 8 | #include <linux/seq_file.h> |
1da177e4 LT |
9 | #include <linux/sysctl.h> |
10 | #include <linux/highmem.h> | |
cddb8a5c | 11 | #include <linux/mmu_notifier.h> |
1da177e4 | 12 | #include <linux/nodemask.h> |
63551ae0 | 13 | #include <linux/pagemap.h> |
5da7ca86 | 14 | #include <linux/mempolicy.h> |
3b32123d | 15 | #include <linux/compiler.h> |
aea47ff3 | 16 | #include <linux/cpuset.h> |
3935baa9 | 17 | #include <linux/mutex.h> |
97ad1087 | 18 | #include <linux/memblock.h> |
a3437870 | 19 | #include <linux/sysfs.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
63489f8e | 21 | #include <linux/mmdebug.h> |
174cd4b1 | 22 | #include <linux/sched/signal.h> |
0fe6e20b | 23 | #include <linux/rmap.h> |
c6247f72 | 24 | #include <linux/string_helpers.h> |
fd6a03ed NH |
25 | #include <linux/swap.h> |
26 | #include <linux/swapops.h> | |
8382d914 | 27 | #include <linux/jhash.h> |
98fa15f3 | 28 | #include <linux/numa.h> |
d6606683 | 29 | |
63551ae0 DG |
30 | #include <asm/page.h> |
31 | #include <asm/pgtable.h> | |
24669e58 | 32 | #include <asm/tlb.h> |
63551ae0 | 33 | |
24669e58 | 34 | #include <linux/io.h> |
63551ae0 | 35 | #include <linux/hugetlb.h> |
9dd540e2 | 36 | #include <linux/hugetlb_cgroup.h> |
9a305230 | 37 | #include <linux/node.h> |
1a1aad8a | 38 | #include <linux/userfaultfd_k.h> |
ab5ac90a | 39 | #include <linux/page_owner.h> |
7835e98b | 40 | #include "internal.h" |
1da177e4 | 41 | |
c3f38a38 | 42 | int hugetlb_max_hstate __read_mostly; |
e5ff2159 AK |
43 | unsigned int default_hstate_idx; |
44 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
641844f5 NH |
45 | /* |
46 | * Minimum page order among possible hugepage sizes, set to a proper value | |
47 | * at boot time. | |
48 | */ | |
49 | static unsigned int minimum_order __read_mostly = UINT_MAX; | |
e5ff2159 | 50 | |
53ba51d2 JT |
51 | __initdata LIST_HEAD(huge_boot_pages); |
52 | ||
e5ff2159 AK |
53 | /* for command line parsing */ |
54 | static struct hstate * __initdata parsed_hstate; | |
55 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 56 | static unsigned long __initdata default_hstate_size; |
9fee021d | 57 | static bool __initdata parsed_valid_hugepagesz = true; |
e5ff2159 | 58 | |
3935baa9 | 59 | /* |
31caf665 NH |
60 | * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, |
61 | * free_huge_pages, and surplus_huge_pages. | |
3935baa9 | 62 | */ |
c3f38a38 | 63 | DEFINE_SPINLOCK(hugetlb_lock); |
0bd0f9fb | 64 | |
8382d914 DB |
65 | /* |
66 | * Serializes faults on the same logical page. This is used to | |
67 | * prevent spurious OOMs when the hugepage pool is fully utilized. | |
68 | */ | |
69 | static int num_fault_mutexes; | |
c672c7f2 | 70 | struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; |
8382d914 | 71 | |
7ca02d0a MK |
72 | /* Forward declaration */ |
73 | static int hugetlb_acct_memory(struct hstate *h, long delta); | |
74 | ||
90481622 DG |
75 | static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) |
76 | { | |
77 | bool free = (spool->count == 0) && (spool->used_hpages == 0); | |
78 | ||
79 | spin_unlock(&spool->lock); | |
80 | ||
81 | /* If no pages are used, and no other handles to the subpool | |
7ca02d0a MK |
82 | * remain, give up any reservations mased on minimum size and |
83 | * free the subpool */ | |
84 | if (free) { | |
85 | if (spool->min_hpages != -1) | |
86 | hugetlb_acct_memory(spool->hstate, | |
87 | -spool->min_hpages); | |
90481622 | 88 | kfree(spool); |
7ca02d0a | 89 | } |
90481622 DG |
90 | } |
91 | ||
7ca02d0a MK |
92 | struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, |
93 | long min_hpages) | |
90481622 DG |
94 | { |
95 | struct hugepage_subpool *spool; | |
96 | ||
c6a91820 | 97 | spool = kzalloc(sizeof(*spool), GFP_KERNEL); |
90481622 DG |
98 | if (!spool) |
99 | return NULL; | |
100 | ||
101 | spin_lock_init(&spool->lock); | |
102 | spool->count = 1; | |
7ca02d0a MK |
103 | spool->max_hpages = max_hpages; |
104 | spool->hstate = h; | |
105 | spool->min_hpages = min_hpages; | |
106 | ||
107 | if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { | |
108 | kfree(spool); | |
109 | return NULL; | |
110 | } | |
111 | spool->rsv_hpages = min_hpages; | |
90481622 DG |
112 | |
113 | return spool; | |
114 | } | |
115 | ||
116 | void hugepage_put_subpool(struct hugepage_subpool *spool) | |
117 | { | |
118 | spin_lock(&spool->lock); | |
119 | BUG_ON(!spool->count); | |
120 | spool->count--; | |
121 | unlock_or_release_subpool(spool); | |
122 | } | |
123 | ||
1c5ecae3 MK |
124 | /* |
125 | * Subpool accounting for allocating and reserving pages. | |
126 | * Return -ENOMEM if there are not enough resources to satisfy the | |
127 | * the request. Otherwise, return the number of pages by which the | |
128 | * global pools must be adjusted (upward). The returned value may | |
129 | * only be different than the passed value (delta) in the case where | |
130 | * a subpool minimum size must be manitained. | |
131 | */ | |
132 | static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, | |
90481622 DG |
133 | long delta) |
134 | { | |
1c5ecae3 | 135 | long ret = delta; |
90481622 DG |
136 | |
137 | if (!spool) | |
1c5ecae3 | 138 | return ret; |
90481622 DG |
139 | |
140 | spin_lock(&spool->lock); | |
1c5ecae3 MK |
141 | |
142 | if (spool->max_hpages != -1) { /* maximum size accounting */ | |
143 | if ((spool->used_hpages + delta) <= spool->max_hpages) | |
144 | spool->used_hpages += delta; | |
145 | else { | |
146 | ret = -ENOMEM; | |
147 | goto unlock_ret; | |
148 | } | |
90481622 | 149 | } |
90481622 | 150 | |
09a95e29 MK |
151 | /* minimum size accounting */ |
152 | if (spool->min_hpages != -1 && spool->rsv_hpages) { | |
1c5ecae3 MK |
153 | if (delta > spool->rsv_hpages) { |
154 | /* | |
155 | * Asking for more reserves than those already taken on | |
156 | * behalf of subpool. Return difference. | |
157 | */ | |
158 | ret = delta - spool->rsv_hpages; | |
159 | spool->rsv_hpages = 0; | |
160 | } else { | |
161 | ret = 0; /* reserves already accounted for */ | |
162 | spool->rsv_hpages -= delta; | |
163 | } | |
164 | } | |
165 | ||
166 | unlock_ret: | |
167 | spin_unlock(&spool->lock); | |
90481622 DG |
168 | return ret; |
169 | } | |
170 | ||
1c5ecae3 MK |
171 | /* |
172 | * Subpool accounting for freeing and unreserving pages. | |
173 | * Return the number of global page reservations that must be dropped. | |
174 | * The return value may only be different than the passed value (delta) | |
175 | * in the case where a subpool minimum size must be maintained. | |
176 | */ | |
177 | static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, | |
90481622 DG |
178 | long delta) |
179 | { | |
1c5ecae3 MK |
180 | long ret = delta; |
181 | ||
90481622 | 182 | if (!spool) |
1c5ecae3 | 183 | return delta; |
90481622 DG |
184 | |
185 | spin_lock(&spool->lock); | |
1c5ecae3 MK |
186 | |
187 | if (spool->max_hpages != -1) /* maximum size accounting */ | |
188 | spool->used_hpages -= delta; | |
189 | ||
09a95e29 MK |
190 | /* minimum size accounting */ |
191 | if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { | |
1c5ecae3 MK |
192 | if (spool->rsv_hpages + delta <= spool->min_hpages) |
193 | ret = 0; | |
194 | else | |
195 | ret = spool->rsv_hpages + delta - spool->min_hpages; | |
196 | ||
197 | spool->rsv_hpages += delta; | |
198 | if (spool->rsv_hpages > spool->min_hpages) | |
199 | spool->rsv_hpages = spool->min_hpages; | |
200 | } | |
201 | ||
202 | /* | |
203 | * If hugetlbfs_put_super couldn't free spool due to an outstanding | |
204 | * quota reference, free it now. | |
205 | */ | |
90481622 | 206 | unlock_or_release_subpool(spool); |
1c5ecae3 MK |
207 | |
208 | return ret; | |
90481622 DG |
209 | } |
210 | ||
211 | static inline struct hugepage_subpool *subpool_inode(struct inode *inode) | |
212 | { | |
213 | return HUGETLBFS_SB(inode->i_sb)->spool; | |
214 | } | |
215 | ||
216 | static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) | |
217 | { | |
496ad9aa | 218 | return subpool_inode(file_inode(vma->vm_file)); |
90481622 DG |
219 | } |
220 | ||
96822904 AW |
221 | /* |
222 | * Region tracking -- allows tracking of reservations and instantiated pages | |
223 | * across the pages in a mapping. | |
84afd99b | 224 | * |
1dd308a7 MK |
225 | * The region data structures are embedded into a resv_map and protected |
226 | * by a resv_map's lock. The set of regions within the resv_map represent | |
227 | * reservations for huge pages, or huge pages that have already been | |
228 | * instantiated within the map. The from and to elements are huge page | |
229 | * indicies into the associated mapping. from indicates the starting index | |
230 | * of the region. to represents the first index past the end of the region. | |
231 | * | |
232 | * For example, a file region structure with from == 0 and to == 4 represents | |
233 | * four huge pages in a mapping. It is important to note that the to element | |
234 | * represents the first element past the end of the region. This is used in | |
235 | * arithmetic as 4(to) - 0(from) = 4 huge pages in the region. | |
236 | * | |
237 | * Interval notation of the form [from, to) will be used to indicate that | |
238 | * the endpoint from is inclusive and to is exclusive. | |
96822904 AW |
239 | */ |
240 | struct file_region { | |
241 | struct list_head link; | |
242 | long from; | |
243 | long to; | |
244 | }; | |
245 | ||
1dd308a7 MK |
246 | /* |
247 | * Add the huge page range represented by [f, t) to the reserve | |
5e911373 MK |
248 | * map. In the normal case, existing regions will be expanded |
249 | * to accommodate the specified range. Sufficient regions should | |
250 | * exist for expansion due to the previous call to region_chg | |
251 | * with the same range. However, it is possible that region_del | |
252 | * could have been called after region_chg and modifed the map | |
253 | * in such a way that no region exists to be expanded. In this | |
254 | * case, pull a region descriptor from the cache associated with | |
255 | * the map and use that for the new range. | |
cf3ad20b MK |
256 | * |
257 | * Return the number of new huge pages added to the map. This | |
258 | * number is greater than or equal to zero. | |
1dd308a7 | 259 | */ |
1406ec9b | 260 | static long region_add(struct resv_map *resv, long f, long t) |
96822904 | 261 | { |
1406ec9b | 262 | struct list_head *head = &resv->regions; |
96822904 | 263 | struct file_region *rg, *nrg, *trg; |
cf3ad20b | 264 | long add = 0; |
96822904 | 265 | |
7b24d861 | 266 | spin_lock(&resv->lock); |
96822904 AW |
267 | /* Locate the region we are either in or before. */ |
268 | list_for_each_entry(rg, head, link) | |
269 | if (f <= rg->to) | |
270 | break; | |
271 | ||
5e911373 MK |
272 | /* |
273 | * If no region exists which can be expanded to include the | |
274 | * specified range, the list must have been modified by an | |
275 | * interleving call to region_del(). Pull a region descriptor | |
276 | * from the cache and use it for this range. | |
277 | */ | |
278 | if (&rg->link == head || t < rg->from) { | |
279 | VM_BUG_ON(resv->region_cache_count <= 0); | |
280 | ||
281 | resv->region_cache_count--; | |
282 | nrg = list_first_entry(&resv->region_cache, struct file_region, | |
283 | link); | |
284 | list_del(&nrg->link); | |
285 | ||
286 | nrg->from = f; | |
287 | nrg->to = t; | |
288 | list_add(&nrg->link, rg->link.prev); | |
289 | ||
290 | add += t - f; | |
291 | goto out_locked; | |
292 | } | |
293 | ||
96822904 AW |
294 | /* Round our left edge to the current segment if it encloses us. */ |
295 | if (f > rg->from) | |
296 | f = rg->from; | |
297 | ||
298 | /* Check for and consume any regions we now overlap with. */ | |
299 | nrg = rg; | |
300 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
301 | if (&rg->link == head) | |
302 | break; | |
303 | if (rg->from > t) | |
304 | break; | |
305 | ||
306 | /* If this area reaches higher then extend our area to | |
307 | * include it completely. If this is not the first area | |
308 | * which we intend to reuse, free it. */ | |
309 | if (rg->to > t) | |
310 | t = rg->to; | |
311 | if (rg != nrg) { | |
cf3ad20b MK |
312 | /* Decrement return value by the deleted range. |
313 | * Another range will span this area so that by | |
314 | * end of routine add will be >= zero | |
315 | */ | |
316 | add -= (rg->to - rg->from); | |
96822904 AW |
317 | list_del(&rg->link); |
318 | kfree(rg); | |
319 | } | |
320 | } | |
cf3ad20b MK |
321 | |
322 | add += (nrg->from - f); /* Added to beginning of region */ | |
96822904 | 323 | nrg->from = f; |
cf3ad20b | 324 | add += t - nrg->to; /* Added to end of region */ |
96822904 | 325 | nrg->to = t; |
cf3ad20b | 326 | |
5e911373 MK |
327 | out_locked: |
328 | resv->adds_in_progress--; | |
7b24d861 | 329 | spin_unlock(&resv->lock); |
cf3ad20b MK |
330 | VM_BUG_ON(add < 0); |
331 | return add; | |
96822904 AW |
332 | } |
333 | ||
1dd308a7 MK |
334 | /* |
335 | * Examine the existing reserve map and determine how many | |
336 | * huge pages in the specified range [f, t) are NOT currently | |
337 | * represented. This routine is called before a subsequent | |
338 | * call to region_add that will actually modify the reserve | |
339 | * map to add the specified range [f, t). region_chg does | |
340 | * not change the number of huge pages represented by the | |
341 | * map. However, if the existing regions in the map can not | |
342 | * be expanded to represent the new range, a new file_region | |
343 | * structure is added to the map as a placeholder. This is | |
344 | * so that the subsequent region_add call will have all the | |
345 | * regions it needs and will not fail. | |
346 | * | |
5e911373 MK |
347 | * Upon entry, region_chg will also examine the cache of region descriptors |
348 | * associated with the map. If there are not enough descriptors cached, one | |
349 | * will be allocated for the in progress add operation. | |
350 | * | |
351 | * Returns the number of huge pages that need to be added to the existing | |
352 | * reservation map for the range [f, t). This number is greater or equal to | |
353 | * zero. -ENOMEM is returned if a new file_region structure or cache entry | |
354 | * is needed and can not be allocated. | |
1dd308a7 | 355 | */ |
1406ec9b | 356 | static long region_chg(struct resv_map *resv, long f, long t) |
96822904 | 357 | { |
1406ec9b | 358 | struct list_head *head = &resv->regions; |
7b24d861 | 359 | struct file_region *rg, *nrg = NULL; |
96822904 AW |
360 | long chg = 0; |
361 | ||
7b24d861 DB |
362 | retry: |
363 | spin_lock(&resv->lock); | |
5e911373 MK |
364 | retry_locked: |
365 | resv->adds_in_progress++; | |
366 | ||
367 | /* | |
368 | * Check for sufficient descriptors in the cache to accommodate | |
369 | * the number of in progress add operations. | |
370 | */ | |
371 | if (resv->adds_in_progress > resv->region_cache_count) { | |
372 | struct file_region *trg; | |
373 | ||
374 | VM_BUG_ON(resv->adds_in_progress - resv->region_cache_count > 1); | |
375 | /* Must drop lock to allocate a new descriptor. */ | |
376 | resv->adds_in_progress--; | |
377 | spin_unlock(&resv->lock); | |
378 | ||
379 | trg = kmalloc(sizeof(*trg), GFP_KERNEL); | |
dbe409e4 MK |
380 | if (!trg) { |
381 | kfree(nrg); | |
5e911373 | 382 | return -ENOMEM; |
dbe409e4 | 383 | } |
5e911373 MK |
384 | |
385 | spin_lock(&resv->lock); | |
386 | list_add(&trg->link, &resv->region_cache); | |
387 | resv->region_cache_count++; | |
388 | goto retry_locked; | |
389 | } | |
390 | ||
96822904 AW |
391 | /* Locate the region we are before or in. */ |
392 | list_for_each_entry(rg, head, link) | |
393 | if (f <= rg->to) | |
394 | break; | |
395 | ||
396 | /* If we are below the current region then a new region is required. | |
397 | * Subtle, allocate a new region at the position but make it zero | |
398 | * size such that we can guarantee to record the reservation. */ | |
399 | if (&rg->link == head || t < rg->from) { | |
7b24d861 | 400 | if (!nrg) { |
5e911373 | 401 | resv->adds_in_progress--; |
7b24d861 DB |
402 | spin_unlock(&resv->lock); |
403 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
404 | if (!nrg) | |
405 | return -ENOMEM; | |
406 | ||
407 | nrg->from = f; | |
408 | nrg->to = f; | |
409 | INIT_LIST_HEAD(&nrg->link); | |
410 | goto retry; | |
411 | } | |
96822904 | 412 | |
7b24d861 DB |
413 | list_add(&nrg->link, rg->link.prev); |
414 | chg = t - f; | |
415 | goto out_nrg; | |
96822904 AW |
416 | } |
417 | ||
418 | /* Round our left edge to the current segment if it encloses us. */ | |
419 | if (f > rg->from) | |
420 | f = rg->from; | |
421 | chg = t - f; | |
422 | ||
423 | /* Check for and consume any regions we now overlap with. */ | |
424 | list_for_each_entry(rg, rg->link.prev, link) { | |
425 | if (&rg->link == head) | |
426 | break; | |
427 | if (rg->from > t) | |
7b24d861 | 428 | goto out; |
96822904 | 429 | |
25985edc | 430 | /* We overlap with this area, if it extends further than |
96822904 AW |
431 | * us then we must extend ourselves. Account for its |
432 | * existing reservation. */ | |
433 | if (rg->to > t) { | |
434 | chg += rg->to - t; | |
435 | t = rg->to; | |
436 | } | |
437 | chg -= rg->to - rg->from; | |
438 | } | |
7b24d861 DB |
439 | |
440 | out: | |
441 | spin_unlock(&resv->lock); | |
442 | /* We already know we raced and no longer need the new region */ | |
443 | kfree(nrg); | |
444 | return chg; | |
445 | out_nrg: | |
446 | spin_unlock(&resv->lock); | |
96822904 AW |
447 | return chg; |
448 | } | |
449 | ||
5e911373 MK |
450 | /* |
451 | * Abort the in progress add operation. The adds_in_progress field | |
452 | * of the resv_map keeps track of the operations in progress between | |
453 | * calls to region_chg and region_add. Operations are sometimes | |
454 | * aborted after the call to region_chg. In such cases, region_abort | |
455 | * is called to decrement the adds_in_progress counter. | |
456 | * | |
457 | * NOTE: The range arguments [f, t) are not needed or used in this | |
458 | * routine. They are kept to make reading the calling code easier as | |
459 | * arguments will match the associated region_chg call. | |
460 | */ | |
461 | static void region_abort(struct resv_map *resv, long f, long t) | |
462 | { | |
463 | spin_lock(&resv->lock); | |
464 | VM_BUG_ON(!resv->region_cache_count); | |
465 | resv->adds_in_progress--; | |
466 | spin_unlock(&resv->lock); | |
467 | } | |
468 | ||
1dd308a7 | 469 | /* |
feba16e2 MK |
470 | * Delete the specified range [f, t) from the reserve map. If the |
471 | * t parameter is LONG_MAX, this indicates that ALL regions after f | |
472 | * should be deleted. Locate the regions which intersect [f, t) | |
473 | * and either trim, delete or split the existing regions. | |
474 | * | |
475 | * Returns the number of huge pages deleted from the reserve map. | |
476 | * In the normal case, the return value is zero or more. In the | |
477 | * case where a region must be split, a new region descriptor must | |
478 | * be allocated. If the allocation fails, -ENOMEM will be returned. | |
479 | * NOTE: If the parameter t == LONG_MAX, then we will never split | |
480 | * a region and possibly return -ENOMEM. Callers specifying | |
481 | * t == LONG_MAX do not need to check for -ENOMEM error. | |
1dd308a7 | 482 | */ |
feba16e2 | 483 | static long region_del(struct resv_map *resv, long f, long t) |
96822904 | 484 | { |
1406ec9b | 485 | struct list_head *head = &resv->regions; |
96822904 | 486 | struct file_region *rg, *trg; |
feba16e2 MK |
487 | struct file_region *nrg = NULL; |
488 | long del = 0; | |
96822904 | 489 | |
feba16e2 | 490 | retry: |
7b24d861 | 491 | spin_lock(&resv->lock); |
feba16e2 | 492 | list_for_each_entry_safe(rg, trg, head, link) { |
dbe409e4 MK |
493 | /* |
494 | * Skip regions before the range to be deleted. file_region | |
495 | * ranges are normally of the form [from, to). However, there | |
496 | * may be a "placeholder" entry in the map which is of the form | |
497 | * (from, to) with from == to. Check for placeholder entries | |
498 | * at the beginning of the range to be deleted. | |
499 | */ | |
500 | if (rg->to <= f && (rg->to != rg->from || rg->to != f)) | |
feba16e2 | 501 | continue; |
dbe409e4 | 502 | |
feba16e2 | 503 | if (rg->from >= t) |
96822904 | 504 | break; |
96822904 | 505 | |
feba16e2 MK |
506 | if (f > rg->from && t < rg->to) { /* Must split region */ |
507 | /* | |
508 | * Check for an entry in the cache before dropping | |
509 | * lock and attempting allocation. | |
510 | */ | |
511 | if (!nrg && | |
512 | resv->region_cache_count > resv->adds_in_progress) { | |
513 | nrg = list_first_entry(&resv->region_cache, | |
514 | struct file_region, | |
515 | link); | |
516 | list_del(&nrg->link); | |
517 | resv->region_cache_count--; | |
518 | } | |
96822904 | 519 | |
feba16e2 MK |
520 | if (!nrg) { |
521 | spin_unlock(&resv->lock); | |
522 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
523 | if (!nrg) | |
524 | return -ENOMEM; | |
525 | goto retry; | |
526 | } | |
527 | ||
528 | del += t - f; | |
529 | ||
530 | /* New entry for end of split region */ | |
531 | nrg->from = t; | |
532 | nrg->to = rg->to; | |
533 | INIT_LIST_HEAD(&nrg->link); | |
534 | ||
535 | /* Original entry is trimmed */ | |
536 | rg->to = f; | |
537 | ||
538 | list_add(&nrg->link, &rg->link); | |
539 | nrg = NULL; | |
96822904 | 540 | break; |
feba16e2 MK |
541 | } |
542 | ||
543 | if (f <= rg->from && t >= rg->to) { /* Remove entire region */ | |
544 | del += rg->to - rg->from; | |
545 | list_del(&rg->link); | |
546 | kfree(rg); | |
547 | continue; | |
548 | } | |
549 | ||
550 | if (f <= rg->from) { /* Trim beginning of region */ | |
551 | del += t - rg->from; | |
552 | rg->from = t; | |
553 | } else { /* Trim end of region */ | |
554 | del += rg->to - f; | |
555 | rg->to = f; | |
556 | } | |
96822904 | 557 | } |
7b24d861 | 558 | |
7b24d861 | 559 | spin_unlock(&resv->lock); |
feba16e2 MK |
560 | kfree(nrg); |
561 | return del; | |
96822904 AW |
562 | } |
563 | ||
b5cec28d MK |
564 | /* |
565 | * A rare out of memory error was encountered which prevented removal of | |
566 | * the reserve map region for a page. The huge page itself was free'ed | |
567 | * and removed from the page cache. This routine will adjust the subpool | |
568 | * usage count, and the global reserve count if needed. By incrementing | |
569 | * these counts, the reserve map entry which could not be deleted will | |
570 | * appear as a "reserved" entry instead of simply dangling with incorrect | |
571 | * counts. | |
572 | */ | |
72e2936c | 573 | void hugetlb_fix_reserve_counts(struct inode *inode) |
b5cec28d MK |
574 | { |
575 | struct hugepage_subpool *spool = subpool_inode(inode); | |
576 | long rsv_adjust; | |
577 | ||
578 | rsv_adjust = hugepage_subpool_get_pages(spool, 1); | |
72e2936c | 579 | if (rsv_adjust) { |
b5cec28d MK |
580 | struct hstate *h = hstate_inode(inode); |
581 | ||
582 | hugetlb_acct_memory(h, 1); | |
583 | } | |
584 | } | |
585 | ||
1dd308a7 MK |
586 | /* |
587 | * Count and return the number of huge pages in the reserve map | |
588 | * that intersect with the range [f, t). | |
589 | */ | |
1406ec9b | 590 | static long region_count(struct resv_map *resv, long f, long t) |
84afd99b | 591 | { |
1406ec9b | 592 | struct list_head *head = &resv->regions; |
84afd99b AW |
593 | struct file_region *rg; |
594 | long chg = 0; | |
595 | ||
7b24d861 | 596 | spin_lock(&resv->lock); |
84afd99b AW |
597 | /* Locate each segment we overlap with, and count that overlap. */ |
598 | list_for_each_entry(rg, head, link) { | |
f2135a4a WSH |
599 | long seg_from; |
600 | long seg_to; | |
84afd99b AW |
601 | |
602 | if (rg->to <= f) | |
603 | continue; | |
604 | if (rg->from >= t) | |
605 | break; | |
606 | ||
607 | seg_from = max(rg->from, f); | |
608 | seg_to = min(rg->to, t); | |
609 | ||
610 | chg += seg_to - seg_from; | |
611 | } | |
7b24d861 | 612 | spin_unlock(&resv->lock); |
84afd99b AW |
613 | |
614 | return chg; | |
615 | } | |
616 | ||
e7c4b0bf AW |
617 | /* |
618 | * Convert the address within this vma to the page offset within | |
619 | * the mapping, in pagecache page units; huge pages here. | |
620 | */ | |
a5516438 AK |
621 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
622 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 623 | { |
a5516438 AK |
624 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
625 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
626 | } |
627 | ||
0fe6e20b NH |
628 | pgoff_t linear_hugepage_index(struct vm_area_struct *vma, |
629 | unsigned long address) | |
630 | { | |
631 | return vma_hugecache_offset(hstate_vma(vma), vma, address); | |
632 | } | |
dee41079 | 633 | EXPORT_SYMBOL_GPL(linear_hugepage_index); |
0fe6e20b | 634 | |
08fba699 MG |
635 | /* |
636 | * Return the size of the pages allocated when backing a VMA. In the majority | |
637 | * cases this will be same size as used by the page table entries. | |
638 | */ | |
639 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) | |
640 | { | |
05ea8860 DW |
641 | if (vma->vm_ops && vma->vm_ops->pagesize) |
642 | return vma->vm_ops->pagesize(vma); | |
643 | return PAGE_SIZE; | |
08fba699 | 644 | } |
f340ca0f | 645 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 646 | |
3340289d MG |
647 | /* |
648 | * Return the page size being used by the MMU to back a VMA. In the majority | |
649 | * of cases, the page size used by the kernel matches the MMU size. On | |
09135cc5 DW |
650 | * architectures where it differs, an architecture-specific 'strong' |
651 | * version of this symbol is required. | |
3340289d | 652 | */ |
09135cc5 | 653 | __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) |
3340289d MG |
654 | { |
655 | return vma_kernel_pagesize(vma); | |
656 | } | |
3340289d | 657 | |
84afd99b AW |
658 | /* |
659 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
660 | * bits of the reservation map pointer, which are always clear due to | |
661 | * alignment. | |
662 | */ | |
663 | #define HPAGE_RESV_OWNER (1UL << 0) | |
664 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 665 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 666 | |
a1e78772 MG |
667 | /* |
668 | * These helpers are used to track how many pages are reserved for | |
669 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
670 | * is guaranteed to have their future faults succeed. | |
671 | * | |
672 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
673 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
674 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
675 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
676 | * |
677 | * The private mapping reservation is represented in a subtly different | |
678 | * manner to a shared mapping. A shared mapping has a region map associated | |
679 | * with the underlying file, this region map represents the backing file | |
680 | * pages which have ever had a reservation assigned which this persists even | |
681 | * after the page is instantiated. A private mapping has a region map | |
682 | * associated with the original mmap which is attached to all VMAs which | |
683 | * reference it, this region map represents those offsets which have consumed | |
684 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 685 | */ |
e7c4b0bf AW |
686 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
687 | { | |
688 | return (unsigned long)vma->vm_private_data; | |
689 | } | |
690 | ||
691 | static void set_vma_private_data(struct vm_area_struct *vma, | |
692 | unsigned long value) | |
693 | { | |
694 | vma->vm_private_data = (void *)value; | |
695 | } | |
696 | ||
9119a41e | 697 | struct resv_map *resv_map_alloc(void) |
84afd99b AW |
698 | { |
699 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
5e911373 MK |
700 | struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); |
701 | ||
702 | if (!resv_map || !rg) { | |
703 | kfree(resv_map); | |
704 | kfree(rg); | |
84afd99b | 705 | return NULL; |
5e911373 | 706 | } |
84afd99b AW |
707 | |
708 | kref_init(&resv_map->refs); | |
7b24d861 | 709 | spin_lock_init(&resv_map->lock); |
84afd99b AW |
710 | INIT_LIST_HEAD(&resv_map->regions); |
711 | ||
5e911373 MK |
712 | resv_map->adds_in_progress = 0; |
713 | ||
714 | INIT_LIST_HEAD(&resv_map->region_cache); | |
715 | list_add(&rg->link, &resv_map->region_cache); | |
716 | resv_map->region_cache_count = 1; | |
717 | ||
84afd99b AW |
718 | return resv_map; |
719 | } | |
720 | ||
9119a41e | 721 | void resv_map_release(struct kref *ref) |
84afd99b AW |
722 | { |
723 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
5e911373 MK |
724 | struct list_head *head = &resv_map->region_cache; |
725 | struct file_region *rg, *trg; | |
84afd99b AW |
726 | |
727 | /* Clear out any active regions before we release the map. */ | |
feba16e2 | 728 | region_del(resv_map, 0, LONG_MAX); |
5e911373 MK |
729 | |
730 | /* ... and any entries left in the cache */ | |
731 | list_for_each_entry_safe(rg, trg, head, link) { | |
732 | list_del(&rg->link); | |
733 | kfree(rg); | |
734 | } | |
735 | ||
736 | VM_BUG_ON(resv_map->adds_in_progress); | |
737 | ||
84afd99b AW |
738 | kfree(resv_map); |
739 | } | |
740 | ||
4e35f483 JK |
741 | static inline struct resv_map *inode_resv_map(struct inode *inode) |
742 | { | |
743 | return inode->i_mapping->private_data; | |
744 | } | |
745 | ||
84afd99b | 746 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) |
a1e78772 | 747 | { |
81d1b09c | 748 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
4e35f483 JK |
749 | if (vma->vm_flags & VM_MAYSHARE) { |
750 | struct address_space *mapping = vma->vm_file->f_mapping; | |
751 | struct inode *inode = mapping->host; | |
752 | ||
753 | return inode_resv_map(inode); | |
754 | ||
755 | } else { | |
84afd99b AW |
756 | return (struct resv_map *)(get_vma_private_data(vma) & |
757 | ~HPAGE_RESV_MASK); | |
4e35f483 | 758 | } |
a1e78772 MG |
759 | } |
760 | ||
84afd99b | 761 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 | 762 | { |
81d1b09c SL |
763 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
764 | VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); | |
a1e78772 | 765 | |
84afd99b AW |
766 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
767 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
768 | } |
769 | ||
770 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
771 | { | |
81d1b09c SL |
772 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
773 | VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); | |
e7c4b0bf AW |
774 | |
775 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
776 | } |
777 | ||
778 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
779 | { | |
81d1b09c | 780 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
e7c4b0bf AW |
781 | |
782 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
783 | } |
784 | ||
04f2cbe3 | 785 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
786 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
787 | { | |
81d1b09c | 788 | VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); |
f83a275d | 789 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
790 | vma->vm_private_data = (void *)0; |
791 | } | |
792 | ||
793 | /* Returns true if the VMA has associated reserve pages */ | |
559ec2f8 | 794 | static bool vma_has_reserves(struct vm_area_struct *vma, long chg) |
a1e78772 | 795 | { |
af0ed73e JK |
796 | if (vma->vm_flags & VM_NORESERVE) { |
797 | /* | |
798 | * This address is already reserved by other process(chg == 0), | |
799 | * so, we should decrement reserved count. Without decrementing, | |
800 | * reserve count remains after releasing inode, because this | |
801 | * allocated page will go into page cache and is regarded as | |
802 | * coming from reserved pool in releasing step. Currently, we | |
803 | * don't have any other solution to deal with this situation | |
804 | * properly, so add work-around here. | |
805 | */ | |
806 | if (vma->vm_flags & VM_MAYSHARE && chg == 0) | |
559ec2f8 | 807 | return true; |
af0ed73e | 808 | else |
559ec2f8 | 809 | return false; |
af0ed73e | 810 | } |
a63884e9 JK |
811 | |
812 | /* Shared mappings always use reserves */ | |
1fb1b0e9 MK |
813 | if (vma->vm_flags & VM_MAYSHARE) { |
814 | /* | |
815 | * We know VM_NORESERVE is not set. Therefore, there SHOULD | |
816 | * be a region map for all pages. The only situation where | |
817 | * there is no region map is if a hole was punched via | |
818 | * fallocate. In this case, there really are no reverves to | |
819 | * use. This situation is indicated if chg != 0. | |
820 | */ | |
821 | if (chg) | |
822 | return false; | |
823 | else | |
824 | return true; | |
825 | } | |
a63884e9 JK |
826 | |
827 | /* | |
828 | * Only the process that called mmap() has reserves for | |
829 | * private mappings. | |
830 | */ | |
67961f9d MK |
831 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
832 | /* | |
833 | * Like the shared case above, a hole punch or truncate | |
834 | * could have been performed on the private mapping. | |
835 | * Examine the value of chg to determine if reserves | |
836 | * actually exist or were previously consumed. | |
837 | * Very Subtle - The value of chg comes from a previous | |
838 | * call to vma_needs_reserves(). The reserve map for | |
839 | * private mappings has different (opposite) semantics | |
840 | * than that of shared mappings. vma_needs_reserves() | |
841 | * has already taken this difference in semantics into | |
842 | * account. Therefore, the meaning of chg is the same | |
843 | * as in the shared case above. Code could easily be | |
844 | * combined, but keeping it separate draws attention to | |
845 | * subtle differences. | |
846 | */ | |
847 | if (chg) | |
848 | return false; | |
849 | else | |
850 | return true; | |
851 | } | |
a63884e9 | 852 | |
559ec2f8 | 853 | return false; |
a1e78772 MG |
854 | } |
855 | ||
a5516438 | 856 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
857 | { |
858 | int nid = page_to_nid(page); | |
0edaecfa | 859 | list_move(&page->lru, &h->hugepage_freelists[nid]); |
a5516438 AK |
860 | h->free_huge_pages++; |
861 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
862 | } |
863 | ||
94310cbc | 864 | static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) |
bf50bab2 NH |
865 | { |
866 | struct page *page; | |
867 | ||
c8721bbb | 868 | list_for_each_entry(page, &h->hugepage_freelists[nid], lru) |
243abd5b | 869 | if (!PageHWPoison(page)) |
c8721bbb NH |
870 | break; |
871 | /* | |
872 | * if 'non-isolated free hugepage' not found on the list, | |
873 | * the allocation fails. | |
874 | */ | |
875 | if (&h->hugepage_freelists[nid] == &page->lru) | |
bf50bab2 | 876 | return NULL; |
0edaecfa | 877 | list_move(&page->lru, &h->hugepage_activelist); |
a9869b83 | 878 | set_page_refcounted(page); |
bf50bab2 NH |
879 | h->free_huge_pages--; |
880 | h->free_huge_pages_node[nid]--; | |
881 | return page; | |
882 | } | |
883 | ||
3e59fcb0 MH |
884 | static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, |
885 | nodemask_t *nmask) | |
94310cbc | 886 | { |
3e59fcb0 MH |
887 | unsigned int cpuset_mems_cookie; |
888 | struct zonelist *zonelist; | |
889 | struct zone *zone; | |
890 | struct zoneref *z; | |
98fa15f3 | 891 | int node = NUMA_NO_NODE; |
94310cbc | 892 | |
3e59fcb0 MH |
893 | zonelist = node_zonelist(nid, gfp_mask); |
894 | ||
895 | retry_cpuset: | |
896 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
897 | for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { | |
898 | struct page *page; | |
899 | ||
900 | if (!cpuset_zone_allowed(zone, gfp_mask)) | |
901 | continue; | |
902 | /* | |
903 | * no need to ask again on the same node. Pool is node rather than | |
904 | * zone aware | |
905 | */ | |
906 | if (zone_to_nid(zone) == node) | |
907 | continue; | |
908 | node = zone_to_nid(zone); | |
94310cbc | 909 | |
94310cbc AK |
910 | page = dequeue_huge_page_node_exact(h, node); |
911 | if (page) | |
912 | return page; | |
913 | } | |
3e59fcb0 MH |
914 | if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) |
915 | goto retry_cpuset; | |
916 | ||
94310cbc AK |
917 | return NULL; |
918 | } | |
919 | ||
86cdb465 NH |
920 | /* Movability of hugepages depends on migration support. */ |
921 | static inline gfp_t htlb_alloc_mask(struct hstate *h) | |
922 | { | |
7ed2c31d | 923 | if (hugepage_movable_supported(h)) |
86cdb465 NH |
924 | return GFP_HIGHUSER_MOVABLE; |
925 | else | |
926 | return GFP_HIGHUSER; | |
927 | } | |
928 | ||
a5516438 AK |
929 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
930 | struct vm_area_struct *vma, | |
af0ed73e JK |
931 | unsigned long address, int avoid_reserve, |
932 | long chg) | |
1da177e4 | 933 | { |
3e59fcb0 | 934 | struct page *page; |
480eccf9 | 935 | struct mempolicy *mpol; |
04ec6264 | 936 | gfp_t gfp_mask; |
3e59fcb0 | 937 | nodemask_t *nodemask; |
04ec6264 | 938 | int nid; |
1da177e4 | 939 | |
a1e78772 MG |
940 | /* |
941 | * A child process with MAP_PRIVATE mappings created by their parent | |
942 | * have no page reserves. This check ensures that reservations are | |
943 | * not "stolen". The child may still get SIGKILLed | |
944 | */ | |
af0ed73e | 945 | if (!vma_has_reserves(vma, chg) && |
a5516438 | 946 | h->free_huge_pages - h->resv_huge_pages == 0) |
c0ff7453 | 947 | goto err; |
a1e78772 | 948 | |
04f2cbe3 | 949 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 950 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
6eab04a8 | 951 | goto err; |
04f2cbe3 | 952 | |
04ec6264 VB |
953 | gfp_mask = htlb_alloc_mask(h); |
954 | nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); | |
3e59fcb0 MH |
955 | page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); |
956 | if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { | |
957 | SetPagePrivate(page); | |
958 | h->resv_huge_pages--; | |
1da177e4 | 959 | } |
cc9a6c87 | 960 | |
52cd3b07 | 961 | mpol_cond_put(mpol); |
1da177e4 | 962 | return page; |
cc9a6c87 MG |
963 | |
964 | err: | |
cc9a6c87 | 965 | return NULL; |
1da177e4 LT |
966 | } |
967 | ||
1cac6f2c LC |
968 | /* |
969 | * common helper functions for hstate_next_node_to_{alloc|free}. | |
970 | * We may have allocated or freed a huge page based on a different | |
971 | * nodes_allowed previously, so h->next_node_to_{alloc|free} might | |
972 | * be outside of *nodes_allowed. Ensure that we use an allowed | |
973 | * node for alloc or free. | |
974 | */ | |
975 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) | |
976 | { | |
0edaf86c | 977 | nid = next_node_in(nid, *nodes_allowed); |
1cac6f2c LC |
978 | VM_BUG_ON(nid >= MAX_NUMNODES); |
979 | ||
980 | return nid; | |
981 | } | |
982 | ||
983 | static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) | |
984 | { | |
985 | if (!node_isset(nid, *nodes_allowed)) | |
986 | nid = next_node_allowed(nid, nodes_allowed); | |
987 | return nid; | |
988 | } | |
989 | ||
990 | /* | |
991 | * returns the previously saved node ["this node"] from which to | |
992 | * allocate a persistent huge page for the pool and advance the | |
993 | * next node from which to allocate, handling wrap at end of node | |
994 | * mask. | |
995 | */ | |
996 | static int hstate_next_node_to_alloc(struct hstate *h, | |
997 | nodemask_t *nodes_allowed) | |
998 | { | |
999 | int nid; | |
1000 | ||
1001 | VM_BUG_ON(!nodes_allowed); | |
1002 | ||
1003 | nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); | |
1004 | h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); | |
1005 | ||
1006 | return nid; | |
1007 | } | |
1008 | ||
1009 | /* | |
1010 | * helper for free_pool_huge_page() - return the previously saved | |
1011 | * node ["this node"] from which to free a huge page. Advance the | |
1012 | * next node id whether or not we find a free huge page to free so | |
1013 | * that the next attempt to free addresses the next node. | |
1014 | */ | |
1015 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) | |
1016 | { | |
1017 | int nid; | |
1018 | ||
1019 | VM_BUG_ON(!nodes_allowed); | |
1020 | ||
1021 | nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); | |
1022 | h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); | |
1023 | ||
1024 | return nid; | |
1025 | } | |
1026 | ||
1027 | #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ | |
1028 | for (nr_nodes = nodes_weight(*mask); \ | |
1029 | nr_nodes > 0 && \ | |
1030 | ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ | |
1031 | nr_nodes--) | |
1032 | ||
1033 | #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ | |
1034 | for (nr_nodes = nodes_weight(*mask); \ | |
1035 | nr_nodes > 0 && \ | |
1036 | ((node = hstate_next_node_to_free(hs, mask)) || 1); \ | |
1037 | nr_nodes--) | |
1038 | ||
e1073d1e | 1039 | #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE |
944d9fec | 1040 | static void destroy_compound_gigantic_page(struct page *page, |
d00181b9 | 1041 | unsigned int order) |
944d9fec LC |
1042 | { |
1043 | int i; | |
1044 | int nr_pages = 1 << order; | |
1045 | struct page *p = page + 1; | |
1046 | ||
c8cc708a | 1047 | atomic_set(compound_mapcount_ptr(page), 0); |
944d9fec | 1048 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
1d798ca3 | 1049 | clear_compound_head(p); |
944d9fec | 1050 | set_page_refcounted(p); |
944d9fec LC |
1051 | } |
1052 | ||
1053 | set_compound_order(page, 0); | |
1054 | __ClearPageHead(page); | |
1055 | } | |
1056 | ||
d00181b9 | 1057 | static void free_gigantic_page(struct page *page, unsigned int order) |
944d9fec LC |
1058 | { |
1059 | free_contig_range(page_to_pfn(page), 1 << order); | |
1060 | } | |
1061 | ||
4eb0716e | 1062 | #ifdef CONFIG_CONTIG_ALLOC |
944d9fec | 1063 | static int __alloc_gigantic_page(unsigned long start_pfn, |
79b63f12 | 1064 | unsigned long nr_pages, gfp_t gfp_mask) |
944d9fec LC |
1065 | { |
1066 | unsigned long end_pfn = start_pfn + nr_pages; | |
ca96b625 | 1067 | return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE, |
79b63f12 | 1068 | gfp_mask); |
944d9fec LC |
1069 | } |
1070 | ||
f44b2dda JK |
1071 | static bool pfn_range_valid_gigantic(struct zone *z, |
1072 | unsigned long start_pfn, unsigned long nr_pages) | |
944d9fec LC |
1073 | { |
1074 | unsigned long i, end_pfn = start_pfn + nr_pages; | |
1075 | struct page *page; | |
1076 | ||
1077 | for (i = start_pfn; i < end_pfn; i++) { | |
1078 | if (!pfn_valid(i)) | |
1079 | return false; | |
1080 | ||
1081 | page = pfn_to_page(i); | |
1082 | ||
f44b2dda JK |
1083 | if (page_zone(page) != z) |
1084 | return false; | |
1085 | ||
944d9fec LC |
1086 | if (PageReserved(page)) |
1087 | return false; | |
1088 | ||
1089 | if (page_count(page) > 0) | |
1090 | return false; | |
1091 | ||
1092 | if (PageHuge(page)) | |
1093 | return false; | |
1094 | } | |
1095 | ||
1096 | return true; | |
1097 | } | |
1098 | ||
1099 | static bool zone_spans_last_pfn(const struct zone *zone, | |
1100 | unsigned long start_pfn, unsigned long nr_pages) | |
1101 | { | |
1102 | unsigned long last_pfn = start_pfn + nr_pages - 1; | |
1103 | return zone_spans_pfn(zone, last_pfn); | |
1104 | } | |
1105 | ||
d9cc948f MH |
1106 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, |
1107 | int nid, nodemask_t *nodemask) | |
944d9fec | 1108 | { |
79b63f12 | 1109 | unsigned int order = huge_page_order(h); |
944d9fec LC |
1110 | unsigned long nr_pages = 1 << order; |
1111 | unsigned long ret, pfn, flags; | |
79b63f12 MH |
1112 | struct zonelist *zonelist; |
1113 | struct zone *zone; | |
1114 | struct zoneref *z; | |
944d9fec | 1115 | |
79b63f12 | 1116 | zonelist = node_zonelist(nid, gfp_mask); |
d9cc948f | 1117 | for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nodemask) { |
79b63f12 | 1118 | spin_lock_irqsave(&zone->lock, flags); |
944d9fec | 1119 | |
79b63f12 MH |
1120 | pfn = ALIGN(zone->zone_start_pfn, nr_pages); |
1121 | while (zone_spans_last_pfn(zone, pfn, nr_pages)) { | |
1122 | if (pfn_range_valid_gigantic(zone, pfn, nr_pages)) { | |
944d9fec LC |
1123 | /* |
1124 | * We release the zone lock here because | |
1125 | * alloc_contig_range() will also lock the zone | |
1126 | * at some point. If there's an allocation | |
1127 | * spinning on this lock, it may win the race | |
1128 | * and cause alloc_contig_range() to fail... | |
1129 | */ | |
79b63f12 MH |
1130 | spin_unlock_irqrestore(&zone->lock, flags); |
1131 | ret = __alloc_gigantic_page(pfn, nr_pages, gfp_mask); | |
944d9fec LC |
1132 | if (!ret) |
1133 | return pfn_to_page(pfn); | |
79b63f12 | 1134 | spin_lock_irqsave(&zone->lock, flags); |
944d9fec LC |
1135 | } |
1136 | pfn += nr_pages; | |
1137 | } | |
1138 | ||
79b63f12 | 1139 | spin_unlock_irqrestore(&zone->lock, flags); |
944d9fec LC |
1140 | } |
1141 | ||
1142 | return NULL; | |
1143 | } | |
1144 | ||
1145 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); | |
d00181b9 | 1146 | static void prep_compound_gigantic_page(struct page *page, unsigned int order); |
4eb0716e AG |
1147 | #else /* !CONFIG_CONTIG_ALLOC */ |
1148 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, | |
1149 | int nid, nodemask_t *nodemask) | |
1150 | { | |
1151 | return NULL; | |
1152 | } | |
1153 | #endif /* CONFIG_CONTIG_ALLOC */ | |
944d9fec | 1154 | |
e1073d1e | 1155 | #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ |
d9cc948f | 1156 | static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, |
4eb0716e AG |
1157 | int nid, nodemask_t *nodemask) |
1158 | { | |
1159 | return NULL; | |
1160 | } | |
d00181b9 | 1161 | static inline void free_gigantic_page(struct page *page, unsigned int order) { } |
944d9fec | 1162 | static inline void destroy_compound_gigantic_page(struct page *page, |
d00181b9 | 1163 | unsigned int order) { } |
944d9fec LC |
1164 | #endif |
1165 | ||
a5516438 | 1166 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
1167 | { |
1168 | int i; | |
a5516438 | 1169 | |
4eb0716e | 1170 | if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) |
944d9fec | 1171 | return; |
18229df5 | 1172 | |
a5516438 AK |
1173 | h->nr_huge_pages--; |
1174 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
1175 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
32f84528 CF |
1176 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | |
1177 | 1 << PG_referenced | 1 << PG_dirty | | |
a7407a27 LC |
1178 | 1 << PG_active | 1 << PG_private | |
1179 | 1 << PG_writeback); | |
6af2acb6 | 1180 | } |
309381fe | 1181 | VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); |
f1e61557 | 1182 | set_compound_page_dtor(page, NULL_COMPOUND_DTOR); |
6af2acb6 | 1183 | set_page_refcounted(page); |
944d9fec LC |
1184 | if (hstate_is_gigantic(h)) { |
1185 | destroy_compound_gigantic_page(page, huge_page_order(h)); | |
1186 | free_gigantic_page(page, huge_page_order(h)); | |
1187 | } else { | |
944d9fec LC |
1188 | __free_pages(page, huge_page_order(h)); |
1189 | } | |
6af2acb6 AL |
1190 | } |
1191 | ||
e5ff2159 AK |
1192 | struct hstate *size_to_hstate(unsigned long size) |
1193 | { | |
1194 | struct hstate *h; | |
1195 | ||
1196 | for_each_hstate(h) { | |
1197 | if (huge_page_size(h) == size) | |
1198 | return h; | |
1199 | } | |
1200 | return NULL; | |
1201 | } | |
1202 | ||
bcc54222 NH |
1203 | /* |
1204 | * Test to determine whether the hugepage is "active/in-use" (i.e. being linked | |
1205 | * to hstate->hugepage_activelist.) | |
1206 | * | |
1207 | * This function can be called for tail pages, but never returns true for them. | |
1208 | */ | |
1209 | bool page_huge_active(struct page *page) | |
1210 | { | |
1211 | VM_BUG_ON_PAGE(!PageHuge(page), page); | |
1212 | return PageHead(page) && PagePrivate(&page[1]); | |
1213 | } | |
1214 | ||
1215 | /* never called for tail page */ | |
1216 | static void set_page_huge_active(struct page *page) | |
1217 | { | |
1218 | VM_BUG_ON_PAGE(!PageHeadHuge(page), page); | |
1219 | SetPagePrivate(&page[1]); | |
1220 | } | |
1221 | ||
1222 | static void clear_page_huge_active(struct page *page) | |
1223 | { | |
1224 | VM_BUG_ON_PAGE(!PageHeadHuge(page), page); | |
1225 | ClearPagePrivate(&page[1]); | |
1226 | } | |
1227 | ||
ab5ac90a MH |
1228 | /* |
1229 | * Internal hugetlb specific page flag. Do not use outside of the hugetlb | |
1230 | * code | |
1231 | */ | |
1232 | static inline bool PageHugeTemporary(struct page *page) | |
1233 | { | |
1234 | if (!PageHuge(page)) | |
1235 | return false; | |
1236 | ||
1237 | return (unsigned long)page[2].mapping == -1U; | |
1238 | } | |
1239 | ||
1240 | static inline void SetPageHugeTemporary(struct page *page) | |
1241 | { | |
1242 | page[2].mapping = (void *)-1U; | |
1243 | } | |
1244 | ||
1245 | static inline void ClearPageHugeTemporary(struct page *page) | |
1246 | { | |
1247 | page[2].mapping = NULL; | |
1248 | } | |
1249 | ||
8f1d26d0 | 1250 | void free_huge_page(struct page *page) |
27a85ef1 | 1251 | { |
a5516438 AK |
1252 | /* |
1253 | * Can't pass hstate in here because it is called from the | |
1254 | * compound page destructor. | |
1255 | */ | |
e5ff2159 | 1256 | struct hstate *h = page_hstate(page); |
7893d1d5 | 1257 | int nid = page_to_nid(page); |
90481622 DG |
1258 | struct hugepage_subpool *spool = |
1259 | (struct hugepage_subpool *)page_private(page); | |
07443a85 | 1260 | bool restore_reserve; |
27a85ef1 | 1261 | |
b4330afb MK |
1262 | VM_BUG_ON_PAGE(page_count(page), page); |
1263 | VM_BUG_ON_PAGE(page_mapcount(page), page); | |
8ace22bc YW |
1264 | |
1265 | set_page_private(page, 0); | |
1266 | page->mapping = NULL; | |
07443a85 | 1267 | restore_reserve = PagePrivate(page); |
16c794b4 | 1268 | ClearPagePrivate(page); |
27a85ef1 | 1269 | |
1c5ecae3 MK |
1270 | /* |
1271 | * A return code of zero implies that the subpool will be under its | |
1272 | * minimum size if the reservation is not restored after page is free. | |
1273 | * Therefore, force restore_reserve operation. | |
1274 | */ | |
1275 | if (hugepage_subpool_put_pages(spool, 1) == 0) | |
1276 | restore_reserve = true; | |
1277 | ||
27a85ef1 | 1278 | spin_lock(&hugetlb_lock); |
bcc54222 | 1279 | clear_page_huge_active(page); |
6d76dcf4 AK |
1280 | hugetlb_cgroup_uncharge_page(hstate_index(h), |
1281 | pages_per_huge_page(h), page); | |
07443a85 JK |
1282 | if (restore_reserve) |
1283 | h->resv_huge_pages++; | |
1284 | ||
ab5ac90a MH |
1285 | if (PageHugeTemporary(page)) { |
1286 | list_del(&page->lru); | |
1287 | ClearPageHugeTemporary(page); | |
1288 | update_and_free_page(h, page); | |
1289 | } else if (h->surplus_huge_pages_node[nid]) { | |
0edaecfa AK |
1290 | /* remove the page from active list */ |
1291 | list_del(&page->lru); | |
a5516438 AK |
1292 | update_and_free_page(h, page); |
1293 | h->surplus_huge_pages--; | |
1294 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 1295 | } else { |
5d3a551c | 1296 | arch_clear_hugepage_flags(page); |
a5516438 | 1297 | enqueue_huge_page(h, page); |
7893d1d5 | 1298 | } |
27a85ef1 DG |
1299 | spin_unlock(&hugetlb_lock); |
1300 | } | |
1301 | ||
a5516438 | 1302 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 | 1303 | { |
0edaecfa | 1304 | INIT_LIST_HEAD(&page->lru); |
f1e61557 | 1305 | set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); |
b7ba30c6 | 1306 | spin_lock(&hugetlb_lock); |
9dd540e2 | 1307 | set_hugetlb_cgroup(page, NULL); |
a5516438 AK |
1308 | h->nr_huge_pages++; |
1309 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 | 1310 | spin_unlock(&hugetlb_lock); |
b7ba30c6 AK |
1311 | } |
1312 | ||
d00181b9 | 1313 | static void prep_compound_gigantic_page(struct page *page, unsigned int order) |
20a0307c WF |
1314 | { |
1315 | int i; | |
1316 | int nr_pages = 1 << order; | |
1317 | struct page *p = page + 1; | |
1318 | ||
1319 | /* we rely on prep_new_huge_page to set the destructor */ | |
1320 | set_compound_order(page, order); | |
ef5a22be | 1321 | __ClearPageReserved(page); |
de09d31d | 1322 | __SetPageHead(page); |
20a0307c | 1323 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
ef5a22be AA |
1324 | /* |
1325 | * For gigantic hugepages allocated through bootmem at | |
1326 | * boot, it's safer to be consistent with the not-gigantic | |
1327 | * hugepages and clear the PG_reserved bit from all tail pages | |
1328 | * too. Otherwse drivers using get_user_pages() to access tail | |
1329 | * pages may get the reference counting wrong if they see | |
1330 | * PG_reserved set on a tail page (despite the head page not | |
1331 | * having PG_reserved set). Enforcing this consistency between | |
1332 | * head and tail pages allows drivers to optimize away a check | |
1333 | * on the head page when they need know if put_page() is needed | |
1334 | * after get_user_pages(). | |
1335 | */ | |
1336 | __ClearPageReserved(p); | |
58a84aa9 | 1337 | set_page_count(p, 0); |
1d798ca3 | 1338 | set_compound_head(p, page); |
20a0307c | 1339 | } |
b4330afb | 1340 | atomic_set(compound_mapcount_ptr(page), -1); |
20a0307c WF |
1341 | } |
1342 | ||
7795912c AM |
1343 | /* |
1344 | * PageHuge() only returns true for hugetlbfs pages, but not for normal or | |
1345 | * transparent huge pages. See the PageTransHuge() documentation for more | |
1346 | * details. | |
1347 | */ | |
20a0307c WF |
1348 | int PageHuge(struct page *page) |
1349 | { | |
20a0307c WF |
1350 | if (!PageCompound(page)) |
1351 | return 0; | |
1352 | ||
1353 | page = compound_head(page); | |
f1e61557 | 1354 | return page[1].compound_dtor == HUGETLB_PAGE_DTOR; |
20a0307c | 1355 | } |
43131e14 NH |
1356 | EXPORT_SYMBOL_GPL(PageHuge); |
1357 | ||
27c73ae7 AA |
1358 | /* |
1359 | * PageHeadHuge() only returns true for hugetlbfs head page, but not for | |
1360 | * normal or transparent huge pages. | |
1361 | */ | |
1362 | int PageHeadHuge(struct page *page_head) | |
1363 | { | |
27c73ae7 AA |
1364 | if (!PageHead(page_head)) |
1365 | return 0; | |
1366 | ||
758f66a2 | 1367 | return get_compound_page_dtor(page_head) == free_huge_page; |
27c73ae7 | 1368 | } |
27c73ae7 | 1369 | |
13d60f4b ZY |
1370 | pgoff_t __basepage_index(struct page *page) |
1371 | { | |
1372 | struct page *page_head = compound_head(page); | |
1373 | pgoff_t index = page_index(page_head); | |
1374 | unsigned long compound_idx; | |
1375 | ||
1376 | if (!PageHuge(page_head)) | |
1377 | return page_index(page); | |
1378 | ||
1379 | if (compound_order(page_head) >= MAX_ORDER) | |
1380 | compound_idx = page_to_pfn(page) - page_to_pfn(page_head); | |
1381 | else | |
1382 | compound_idx = page - page_head; | |
1383 | ||
1384 | return (index << compound_order(page_head)) + compound_idx; | |
1385 | } | |
1386 | ||
0c397dae | 1387 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
af0fb9df | 1388 | gfp_t gfp_mask, int nid, nodemask_t *nmask) |
1da177e4 | 1389 | { |
af0fb9df | 1390 | int order = huge_page_order(h); |
1da177e4 | 1391 | struct page *page; |
f96efd58 | 1392 | |
af0fb9df MH |
1393 | gfp_mask |= __GFP_COMP|__GFP_RETRY_MAYFAIL|__GFP_NOWARN; |
1394 | if (nid == NUMA_NO_NODE) | |
1395 | nid = numa_mem_id(); | |
1396 | page = __alloc_pages_nodemask(gfp_mask, order, nid, nmask); | |
1397 | if (page) | |
1398 | __count_vm_event(HTLB_BUDDY_PGALLOC); | |
1399 | else | |
1400 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
63b4613c NA |
1401 | |
1402 | return page; | |
1403 | } | |
1404 | ||
0c397dae MH |
1405 | /* |
1406 | * Common helper to allocate a fresh hugetlb page. All specific allocators | |
1407 | * should use this function to get new hugetlb pages | |
1408 | */ | |
1409 | static struct page *alloc_fresh_huge_page(struct hstate *h, | |
1410 | gfp_t gfp_mask, int nid, nodemask_t *nmask) | |
1411 | { | |
1412 | struct page *page; | |
1413 | ||
1414 | if (hstate_is_gigantic(h)) | |
1415 | page = alloc_gigantic_page(h, gfp_mask, nid, nmask); | |
1416 | else | |
1417 | page = alloc_buddy_huge_page(h, gfp_mask, | |
1418 | nid, nmask); | |
1419 | if (!page) | |
1420 | return NULL; | |
1421 | ||
1422 | if (hstate_is_gigantic(h)) | |
1423 | prep_compound_gigantic_page(page, huge_page_order(h)); | |
1424 | prep_new_huge_page(h, page, page_to_nid(page)); | |
1425 | ||
1426 | return page; | |
1427 | } | |
1428 | ||
af0fb9df MH |
1429 | /* |
1430 | * Allocates a fresh page to the hugetlb allocator pool in the node interleaved | |
1431 | * manner. | |
1432 | */ | |
0c397dae | 1433 | static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) |
b2261026 JK |
1434 | { |
1435 | struct page *page; | |
1436 | int nr_nodes, node; | |
af0fb9df | 1437 | gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; |
b2261026 JK |
1438 | |
1439 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
0c397dae | 1440 | page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed); |
af0fb9df | 1441 | if (page) |
b2261026 | 1442 | break; |
b2261026 JK |
1443 | } |
1444 | ||
af0fb9df MH |
1445 | if (!page) |
1446 | return 0; | |
b2261026 | 1447 | |
af0fb9df MH |
1448 | put_page(page); /* free it into the hugepage allocator */ |
1449 | ||
1450 | return 1; | |
b2261026 JK |
1451 | } |
1452 | ||
e8c5c824 LS |
1453 | /* |
1454 | * Free huge page from pool from next node to free. | |
1455 | * Attempt to keep persistent huge pages more or less | |
1456 | * balanced over allowed nodes. | |
1457 | * Called with hugetlb_lock locked. | |
1458 | */ | |
6ae11b27 LS |
1459 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
1460 | bool acct_surplus) | |
e8c5c824 | 1461 | { |
b2261026 | 1462 | int nr_nodes, node; |
e8c5c824 LS |
1463 | int ret = 0; |
1464 | ||
b2261026 | 1465 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { |
685f3457 LS |
1466 | /* |
1467 | * If we're returning unused surplus pages, only examine | |
1468 | * nodes with surplus pages. | |
1469 | */ | |
b2261026 JK |
1470 | if ((!acct_surplus || h->surplus_huge_pages_node[node]) && |
1471 | !list_empty(&h->hugepage_freelists[node])) { | |
e8c5c824 | 1472 | struct page *page = |
b2261026 | 1473 | list_entry(h->hugepage_freelists[node].next, |
e8c5c824 LS |
1474 | struct page, lru); |
1475 | list_del(&page->lru); | |
1476 | h->free_huge_pages--; | |
b2261026 | 1477 | h->free_huge_pages_node[node]--; |
685f3457 LS |
1478 | if (acct_surplus) { |
1479 | h->surplus_huge_pages--; | |
b2261026 | 1480 | h->surplus_huge_pages_node[node]--; |
685f3457 | 1481 | } |
e8c5c824 LS |
1482 | update_and_free_page(h, page); |
1483 | ret = 1; | |
9a76db09 | 1484 | break; |
e8c5c824 | 1485 | } |
b2261026 | 1486 | } |
e8c5c824 LS |
1487 | |
1488 | return ret; | |
1489 | } | |
1490 | ||
c8721bbb NH |
1491 | /* |
1492 | * Dissolve a given free hugepage into free buddy pages. This function does | |
082d5b6b | 1493 | * nothing for in-use (including surplus) hugepages. Returns -EBUSY if the |
6bc9b564 NH |
1494 | * dissolution fails because a give page is not a free hugepage, or because |
1495 | * free hugepages are fully reserved. | |
c8721bbb | 1496 | */ |
c3114a84 | 1497 | int dissolve_free_huge_page(struct page *page) |
c8721bbb | 1498 | { |
6bc9b564 | 1499 | int rc = -EBUSY; |
082d5b6b | 1500 | |
c8721bbb NH |
1501 | spin_lock(&hugetlb_lock); |
1502 | if (PageHuge(page) && !page_count(page)) { | |
2247bb33 GS |
1503 | struct page *head = compound_head(page); |
1504 | struct hstate *h = page_hstate(head); | |
1505 | int nid = page_to_nid(head); | |
6bc9b564 | 1506 | if (h->free_huge_pages - h->resv_huge_pages == 0) |
082d5b6b | 1507 | goto out; |
c3114a84 AK |
1508 | /* |
1509 | * Move PageHWPoison flag from head page to the raw error page, | |
1510 | * which makes any subpages rather than the error page reusable. | |
1511 | */ | |
1512 | if (PageHWPoison(head) && page != head) { | |
1513 | SetPageHWPoison(page); | |
1514 | ClearPageHWPoison(head); | |
1515 | } | |
2247bb33 | 1516 | list_del(&head->lru); |
c8721bbb NH |
1517 | h->free_huge_pages--; |
1518 | h->free_huge_pages_node[nid]--; | |
c1470b33 | 1519 | h->max_huge_pages--; |
2247bb33 | 1520 | update_and_free_page(h, head); |
6bc9b564 | 1521 | rc = 0; |
c8721bbb | 1522 | } |
082d5b6b | 1523 | out: |
c8721bbb | 1524 | spin_unlock(&hugetlb_lock); |
082d5b6b | 1525 | return rc; |
c8721bbb NH |
1526 | } |
1527 | ||
1528 | /* | |
1529 | * Dissolve free hugepages in a given pfn range. Used by memory hotplug to | |
1530 | * make specified memory blocks removable from the system. | |
2247bb33 GS |
1531 | * Note that this will dissolve a free gigantic hugepage completely, if any |
1532 | * part of it lies within the given range. | |
082d5b6b GS |
1533 | * Also note that if dissolve_free_huge_page() returns with an error, all |
1534 | * free hugepages that were dissolved before that error are lost. | |
c8721bbb | 1535 | */ |
082d5b6b | 1536 | int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) |
c8721bbb | 1537 | { |
c8721bbb | 1538 | unsigned long pfn; |
eb03aa00 | 1539 | struct page *page; |
082d5b6b | 1540 | int rc = 0; |
c8721bbb | 1541 | |
d0177639 | 1542 | if (!hugepages_supported()) |
082d5b6b | 1543 | return rc; |
d0177639 | 1544 | |
eb03aa00 GS |
1545 | for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { |
1546 | page = pfn_to_page(pfn); | |
1547 | if (PageHuge(page) && !page_count(page)) { | |
1548 | rc = dissolve_free_huge_page(page); | |
1549 | if (rc) | |
1550 | break; | |
1551 | } | |
1552 | } | |
082d5b6b GS |
1553 | |
1554 | return rc; | |
c8721bbb NH |
1555 | } |
1556 | ||
ab5ac90a MH |
1557 | /* |
1558 | * Allocates a fresh surplus page from the page allocator. | |
1559 | */ | |
0c397dae | 1560 | static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, |
aaf14e40 | 1561 | int nid, nodemask_t *nmask) |
7893d1d5 | 1562 | { |
9980d744 | 1563 | struct page *page = NULL; |
7893d1d5 | 1564 | |
bae7f4ae | 1565 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
1566 | return NULL; |
1567 | ||
d1c3fb1f | 1568 | spin_lock(&hugetlb_lock); |
9980d744 MH |
1569 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) |
1570 | goto out_unlock; | |
d1c3fb1f NA |
1571 | spin_unlock(&hugetlb_lock); |
1572 | ||
0c397dae | 1573 | page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask); |
9980d744 | 1574 | if (!page) |
0c397dae | 1575 | return NULL; |
d1c3fb1f NA |
1576 | |
1577 | spin_lock(&hugetlb_lock); | |
9980d744 MH |
1578 | /* |
1579 | * We could have raced with the pool size change. | |
1580 | * Double check that and simply deallocate the new page | |
1581 | * if we would end up overcommiting the surpluses. Abuse | |
1582 | * temporary page to workaround the nasty free_huge_page | |
1583 | * codeflow | |
1584 | */ | |
1585 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { | |
1586 | SetPageHugeTemporary(page); | |
2bf753e6 | 1587 | spin_unlock(&hugetlb_lock); |
9980d744 | 1588 | put_page(page); |
2bf753e6 | 1589 | return NULL; |
9980d744 | 1590 | } else { |
9980d744 | 1591 | h->surplus_huge_pages++; |
4704dea3 | 1592 | h->surplus_huge_pages_node[page_to_nid(page)]++; |
7893d1d5 | 1593 | } |
9980d744 MH |
1594 | |
1595 | out_unlock: | |
d1c3fb1f | 1596 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
1597 | |
1598 | return page; | |
1599 | } | |
1600 | ||
9a4e9f3b AK |
1601 | struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, |
1602 | int nid, nodemask_t *nmask) | |
ab5ac90a MH |
1603 | { |
1604 | struct page *page; | |
1605 | ||
1606 | if (hstate_is_gigantic(h)) | |
1607 | return NULL; | |
1608 | ||
0c397dae | 1609 | page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask); |
ab5ac90a MH |
1610 | if (!page) |
1611 | return NULL; | |
1612 | ||
1613 | /* | |
1614 | * We do not account these pages as surplus because they are only | |
1615 | * temporary and will be released properly on the last reference | |
1616 | */ | |
ab5ac90a MH |
1617 | SetPageHugeTemporary(page); |
1618 | ||
1619 | return page; | |
1620 | } | |
1621 | ||
099730d6 DH |
1622 | /* |
1623 | * Use the VMA's mpolicy to allocate a huge page from the buddy. | |
1624 | */ | |
e0ec90ee | 1625 | static |
0c397dae | 1626 | struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, |
099730d6 DH |
1627 | struct vm_area_struct *vma, unsigned long addr) |
1628 | { | |
aaf14e40 MH |
1629 | struct page *page; |
1630 | struct mempolicy *mpol; | |
1631 | gfp_t gfp_mask = htlb_alloc_mask(h); | |
1632 | int nid; | |
1633 | nodemask_t *nodemask; | |
1634 | ||
1635 | nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); | |
0c397dae | 1636 | page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); |
aaf14e40 MH |
1637 | mpol_cond_put(mpol); |
1638 | ||
1639 | return page; | |
099730d6 DH |
1640 | } |
1641 | ||
ab5ac90a | 1642 | /* page migration callback function */ |
bf50bab2 NH |
1643 | struct page *alloc_huge_page_node(struct hstate *h, int nid) |
1644 | { | |
aaf14e40 | 1645 | gfp_t gfp_mask = htlb_alloc_mask(h); |
4ef91848 | 1646 | struct page *page = NULL; |
bf50bab2 | 1647 | |
aaf14e40 MH |
1648 | if (nid != NUMA_NO_NODE) |
1649 | gfp_mask |= __GFP_THISNODE; | |
1650 | ||
bf50bab2 | 1651 | spin_lock(&hugetlb_lock); |
4ef91848 | 1652 | if (h->free_huge_pages - h->resv_huge_pages > 0) |
3e59fcb0 | 1653 | page = dequeue_huge_page_nodemask(h, gfp_mask, nid, NULL); |
bf50bab2 NH |
1654 | spin_unlock(&hugetlb_lock); |
1655 | ||
94ae8ba7 | 1656 | if (!page) |
0c397dae | 1657 | page = alloc_migrate_huge_page(h, gfp_mask, nid, NULL); |
bf50bab2 NH |
1658 | |
1659 | return page; | |
1660 | } | |
1661 | ||
ab5ac90a | 1662 | /* page migration callback function */ |
3e59fcb0 MH |
1663 | struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, |
1664 | nodemask_t *nmask) | |
4db9b2ef | 1665 | { |
aaf14e40 | 1666 | gfp_t gfp_mask = htlb_alloc_mask(h); |
4db9b2ef MH |
1667 | |
1668 | spin_lock(&hugetlb_lock); | |
1669 | if (h->free_huge_pages - h->resv_huge_pages > 0) { | |
3e59fcb0 MH |
1670 | struct page *page; |
1671 | ||
1672 | page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); | |
1673 | if (page) { | |
1674 | spin_unlock(&hugetlb_lock); | |
1675 | return page; | |
4db9b2ef MH |
1676 | } |
1677 | } | |
1678 | spin_unlock(&hugetlb_lock); | |
4db9b2ef | 1679 | |
0c397dae | 1680 | return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); |
4db9b2ef MH |
1681 | } |
1682 | ||
ebd63723 | 1683 | /* mempolicy aware migration callback */ |
389c8178 MH |
1684 | struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, |
1685 | unsigned long address) | |
ebd63723 MH |
1686 | { |
1687 | struct mempolicy *mpol; | |
1688 | nodemask_t *nodemask; | |
1689 | struct page *page; | |
ebd63723 MH |
1690 | gfp_t gfp_mask; |
1691 | int node; | |
1692 | ||
ebd63723 MH |
1693 | gfp_mask = htlb_alloc_mask(h); |
1694 | node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); | |
1695 | page = alloc_huge_page_nodemask(h, node, nodemask); | |
1696 | mpol_cond_put(mpol); | |
1697 | ||
1698 | return page; | |
1699 | } | |
1700 | ||
e4e574b7 | 1701 | /* |
25985edc | 1702 | * Increase the hugetlb pool such that it can accommodate a reservation |
e4e574b7 AL |
1703 | * of size 'delta'. |
1704 | */ | |
a5516438 | 1705 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
1706 | { |
1707 | struct list_head surplus_list; | |
1708 | struct page *page, *tmp; | |
1709 | int ret, i; | |
1710 | int needed, allocated; | |
28073b02 | 1711 | bool alloc_ok = true; |
e4e574b7 | 1712 | |
a5516438 | 1713 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 1714 | if (needed <= 0) { |
a5516438 | 1715 | h->resv_huge_pages += delta; |
e4e574b7 | 1716 | return 0; |
ac09b3a1 | 1717 | } |
e4e574b7 AL |
1718 | |
1719 | allocated = 0; | |
1720 | INIT_LIST_HEAD(&surplus_list); | |
1721 | ||
1722 | ret = -ENOMEM; | |
1723 | retry: | |
1724 | spin_unlock(&hugetlb_lock); | |
1725 | for (i = 0; i < needed; i++) { | |
0c397dae | 1726 | page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), |
aaf14e40 | 1727 | NUMA_NO_NODE, NULL); |
28073b02 HD |
1728 | if (!page) { |
1729 | alloc_ok = false; | |
1730 | break; | |
1731 | } | |
e4e574b7 | 1732 | list_add(&page->lru, &surplus_list); |
69ed779a | 1733 | cond_resched(); |
e4e574b7 | 1734 | } |
28073b02 | 1735 | allocated += i; |
e4e574b7 AL |
1736 | |
1737 | /* | |
1738 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
1739 | * because either resv_huge_pages or free_huge_pages may have changed. | |
1740 | */ | |
1741 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
1742 | needed = (h->resv_huge_pages + delta) - |
1743 | (h->free_huge_pages + allocated); | |
28073b02 HD |
1744 | if (needed > 0) { |
1745 | if (alloc_ok) | |
1746 | goto retry; | |
1747 | /* | |
1748 | * We were not able to allocate enough pages to | |
1749 | * satisfy the entire reservation so we free what | |
1750 | * we've allocated so far. | |
1751 | */ | |
1752 | goto free; | |
1753 | } | |
e4e574b7 AL |
1754 | /* |
1755 | * The surplus_list now contains _at_least_ the number of extra pages | |
25985edc | 1756 | * needed to accommodate the reservation. Add the appropriate number |
e4e574b7 | 1757 | * of pages to the hugetlb pool and free the extras back to the buddy |
ac09b3a1 AL |
1758 | * allocator. Commit the entire reservation here to prevent another |
1759 | * process from stealing the pages as they are added to the pool but | |
1760 | * before they are reserved. | |
e4e574b7 AL |
1761 | */ |
1762 | needed += allocated; | |
a5516438 | 1763 | h->resv_huge_pages += delta; |
e4e574b7 | 1764 | ret = 0; |
a9869b83 | 1765 | |
19fc3f0a | 1766 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 1767 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
1768 | if ((--needed) < 0) |
1769 | break; | |
a9869b83 NH |
1770 | /* |
1771 | * This page is now managed by the hugetlb allocator and has | |
1772 | * no users -- drop the buddy allocator's reference. | |
1773 | */ | |
1774 | put_page_testzero(page); | |
309381fe | 1775 | VM_BUG_ON_PAGE(page_count(page), page); |
a5516438 | 1776 | enqueue_huge_page(h, page); |
19fc3f0a | 1777 | } |
28073b02 | 1778 | free: |
b0365c8d | 1779 | spin_unlock(&hugetlb_lock); |
19fc3f0a AL |
1780 | |
1781 | /* Free unnecessary surplus pages to the buddy allocator */ | |
c0d934ba JK |
1782 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) |
1783 | put_page(page); | |
a9869b83 | 1784 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
1785 | |
1786 | return ret; | |
1787 | } | |
1788 | ||
1789 | /* | |
e5bbc8a6 MK |
1790 | * This routine has two main purposes: |
1791 | * 1) Decrement the reservation count (resv_huge_pages) by the value passed | |
1792 | * in unused_resv_pages. This corresponds to the prior adjustments made | |
1793 | * to the associated reservation map. | |
1794 | * 2) Free any unused surplus pages that may have been allocated to satisfy | |
1795 | * the reservation. As many as unused_resv_pages may be freed. | |
1796 | * | |
1797 | * Called with hugetlb_lock held. However, the lock could be dropped (and | |
1798 | * reacquired) during calls to cond_resched_lock. Whenever dropping the lock, | |
1799 | * we must make sure nobody else can claim pages we are in the process of | |
1800 | * freeing. Do this by ensuring resv_huge_page always is greater than the | |
1801 | * number of huge pages we plan to free when dropping the lock. | |
e4e574b7 | 1802 | */ |
a5516438 AK |
1803 | static void return_unused_surplus_pages(struct hstate *h, |
1804 | unsigned long unused_resv_pages) | |
e4e574b7 | 1805 | { |
e4e574b7 AL |
1806 | unsigned long nr_pages; |
1807 | ||
aa888a74 | 1808 | /* Cannot return gigantic pages currently */ |
bae7f4ae | 1809 | if (hstate_is_gigantic(h)) |
e5bbc8a6 | 1810 | goto out; |
aa888a74 | 1811 | |
e5bbc8a6 MK |
1812 | /* |
1813 | * Part (or even all) of the reservation could have been backed | |
1814 | * by pre-allocated pages. Only free surplus pages. | |
1815 | */ | |
a5516438 | 1816 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 1817 | |
685f3457 LS |
1818 | /* |
1819 | * We want to release as many surplus pages as possible, spread | |
9b5e5d0f LS |
1820 | * evenly across all nodes with memory. Iterate across these nodes |
1821 | * until we can no longer free unreserved surplus pages. This occurs | |
1822 | * when the nodes with surplus pages have no free pages. | |
1823 | * free_pool_huge_page() will balance the the freed pages across the | |
1824 | * on-line nodes with memory and will handle the hstate accounting. | |
e5bbc8a6 MK |
1825 | * |
1826 | * Note that we decrement resv_huge_pages as we free the pages. If | |
1827 | * we drop the lock, resv_huge_pages will still be sufficiently large | |
1828 | * to cover subsequent pages we may free. | |
685f3457 LS |
1829 | */ |
1830 | while (nr_pages--) { | |
e5bbc8a6 MK |
1831 | h->resv_huge_pages--; |
1832 | unused_resv_pages--; | |
8cebfcd0 | 1833 | if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) |
e5bbc8a6 | 1834 | goto out; |
7848a4bf | 1835 | cond_resched_lock(&hugetlb_lock); |
e4e574b7 | 1836 | } |
e5bbc8a6 MK |
1837 | |
1838 | out: | |
1839 | /* Fully uncommit the reservation */ | |
1840 | h->resv_huge_pages -= unused_resv_pages; | |
e4e574b7 AL |
1841 | } |
1842 | ||
5e911373 | 1843 | |
c37f9fb1 | 1844 | /* |
feba16e2 | 1845 | * vma_needs_reservation, vma_commit_reservation and vma_end_reservation |
5e911373 | 1846 | * are used by the huge page allocation routines to manage reservations. |
cf3ad20b MK |
1847 | * |
1848 | * vma_needs_reservation is called to determine if the huge page at addr | |
1849 | * within the vma has an associated reservation. If a reservation is | |
1850 | * needed, the value 1 is returned. The caller is then responsible for | |
1851 | * managing the global reservation and subpool usage counts. After | |
1852 | * the huge page has been allocated, vma_commit_reservation is called | |
feba16e2 MK |
1853 | * to add the page to the reservation map. If the page allocation fails, |
1854 | * the reservation must be ended instead of committed. vma_end_reservation | |
1855 | * is called in such cases. | |
cf3ad20b MK |
1856 | * |
1857 | * In the normal case, vma_commit_reservation returns the same value | |
1858 | * as the preceding vma_needs_reservation call. The only time this | |
1859 | * is not the case is if a reserve map was changed between calls. It | |
1860 | * is the responsibility of the caller to notice the difference and | |
1861 | * take appropriate action. | |
96b96a96 MK |
1862 | * |
1863 | * vma_add_reservation is used in error paths where a reservation must | |
1864 | * be restored when a newly allocated huge page must be freed. It is | |
1865 | * to be called after calling vma_needs_reservation to determine if a | |
1866 | * reservation exists. | |
c37f9fb1 | 1867 | */ |
5e911373 MK |
1868 | enum vma_resv_mode { |
1869 | VMA_NEEDS_RESV, | |
1870 | VMA_COMMIT_RESV, | |
feba16e2 | 1871 | VMA_END_RESV, |
96b96a96 | 1872 | VMA_ADD_RESV, |
5e911373 | 1873 | }; |
cf3ad20b MK |
1874 | static long __vma_reservation_common(struct hstate *h, |
1875 | struct vm_area_struct *vma, unsigned long addr, | |
5e911373 | 1876 | enum vma_resv_mode mode) |
c37f9fb1 | 1877 | { |
4e35f483 JK |
1878 | struct resv_map *resv; |
1879 | pgoff_t idx; | |
cf3ad20b | 1880 | long ret; |
c37f9fb1 | 1881 | |
4e35f483 JK |
1882 | resv = vma_resv_map(vma); |
1883 | if (!resv) | |
84afd99b | 1884 | return 1; |
c37f9fb1 | 1885 | |
4e35f483 | 1886 | idx = vma_hugecache_offset(h, vma, addr); |
5e911373 MK |
1887 | switch (mode) { |
1888 | case VMA_NEEDS_RESV: | |
cf3ad20b | 1889 | ret = region_chg(resv, idx, idx + 1); |
5e911373 MK |
1890 | break; |
1891 | case VMA_COMMIT_RESV: | |
1892 | ret = region_add(resv, idx, idx + 1); | |
1893 | break; | |
feba16e2 | 1894 | case VMA_END_RESV: |
5e911373 MK |
1895 | region_abort(resv, idx, idx + 1); |
1896 | ret = 0; | |
1897 | break; | |
96b96a96 MK |
1898 | case VMA_ADD_RESV: |
1899 | if (vma->vm_flags & VM_MAYSHARE) | |
1900 | ret = region_add(resv, idx, idx + 1); | |
1901 | else { | |
1902 | region_abort(resv, idx, idx + 1); | |
1903 | ret = region_del(resv, idx, idx + 1); | |
1904 | } | |
1905 | break; | |
5e911373 MK |
1906 | default: |
1907 | BUG(); | |
1908 | } | |
84afd99b | 1909 | |
4e35f483 | 1910 | if (vma->vm_flags & VM_MAYSHARE) |
cf3ad20b | 1911 | return ret; |
67961f9d MK |
1912 | else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) { |
1913 | /* | |
1914 | * In most cases, reserves always exist for private mappings. | |
1915 | * However, a file associated with mapping could have been | |
1916 | * hole punched or truncated after reserves were consumed. | |
1917 | * As subsequent fault on such a range will not use reserves. | |
1918 | * Subtle - The reserve map for private mappings has the | |
1919 | * opposite meaning than that of shared mappings. If NO | |
1920 | * entry is in the reserve map, it means a reservation exists. | |
1921 | * If an entry exists in the reserve map, it means the | |
1922 | * reservation has already been consumed. As a result, the | |
1923 | * return value of this routine is the opposite of the | |
1924 | * value returned from reserve map manipulation routines above. | |
1925 | */ | |
1926 | if (ret) | |
1927 | return 0; | |
1928 | else | |
1929 | return 1; | |
1930 | } | |
4e35f483 | 1931 | else |
cf3ad20b | 1932 | return ret < 0 ? ret : 0; |
c37f9fb1 | 1933 | } |
cf3ad20b MK |
1934 | |
1935 | static long vma_needs_reservation(struct hstate *h, | |
a5516438 | 1936 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 | 1937 | { |
5e911373 | 1938 | return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); |
cf3ad20b | 1939 | } |
84afd99b | 1940 | |
cf3ad20b MK |
1941 | static long vma_commit_reservation(struct hstate *h, |
1942 | struct vm_area_struct *vma, unsigned long addr) | |
1943 | { | |
5e911373 MK |
1944 | return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); |
1945 | } | |
1946 | ||
feba16e2 | 1947 | static void vma_end_reservation(struct hstate *h, |
5e911373 MK |
1948 | struct vm_area_struct *vma, unsigned long addr) |
1949 | { | |
feba16e2 | 1950 | (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); |
c37f9fb1 AW |
1951 | } |
1952 | ||
96b96a96 MK |
1953 | static long vma_add_reservation(struct hstate *h, |
1954 | struct vm_area_struct *vma, unsigned long addr) | |
1955 | { | |
1956 | return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); | |
1957 | } | |
1958 | ||
1959 | /* | |
1960 | * This routine is called to restore a reservation on error paths. In the | |
1961 | * specific error paths, a huge page was allocated (via alloc_huge_page) | |
1962 | * and is about to be freed. If a reservation for the page existed, | |
1963 | * alloc_huge_page would have consumed the reservation and set PagePrivate | |
1964 | * in the newly allocated page. When the page is freed via free_huge_page, | |
1965 | * the global reservation count will be incremented if PagePrivate is set. | |
1966 | * However, free_huge_page can not adjust the reserve map. Adjust the | |
1967 | * reserve map here to be consistent with global reserve count adjustments | |
1968 | * to be made by free_huge_page. | |
1969 | */ | |
1970 | static void restore_reserve_on_error(struct hstate *h, | |
1971 | struct vm_area_struct *vma, unsigned long address, | |
1972 | struct page *page) | |
1973 | { | |
1974 | if (unlikely(PagePrivate(page))) { | |
1975 | long rc = vma_needs_reservation(h, vma, address); | |
1976 | ||
1977 | if (unlikely(rc < 0)) { | |
1978 | /* | |
1979 | * Rare out of memory condition in reserve map | |
1980 | * manipulation. Clear PagePrivate so that | |
1981 | * global reserve count will not be incremented | |
1982 | * by free_huge_page. This will make it appear | |
1983 | * as though the reservation for this page was | |
1984 | * consumed. This may prevent the task from | |
1985 | * faulting in the page at a later time. This | |
1986 | * is better than inconsistent global huge page | |
1987 | * accounting of reserve counts. | |
1988 | */ | |
1989 | ClearPagePrivate(page); | |
1990 | } else if (rc) { | |
1991 | rc = vma_add_reservation(h, vma, address); | |
1992 | if (unlikely(rc < 0)) | |
1993 | /* | |
1994 | * See above comment about rare out of | |
1995 | * memory condition. | |
1996 | */ | |
1997 | ClearPagePrivate(page); | |
1998 | } else | |
1999 | vma_end_reservation(h, vma, address); | |
2000 | } | |
2001 | } | |
2002 | ||
70c3547e | 2003 | struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 2004 | unsigned long addr, int avoid_reserve) |
1da177e4 | 2005 | { |
90481622 | 2006 | struct hugepage_subpool *spool = subpool_vma(vma); |
a5516438 | 2007 | struct hstate *h = hstate_vma(vma); |
348ea204 | 2008 | struct page *page; |
d85f69b0 MK |
2009 | long map_chg, map_commit; |
2010 | long gbl_chg; | |
6d76dcf4 AK |
2011 | int ret, idx; |
2012 | struct hugetlb_cgroup *h_cg; | |
a1e78772 | 2013 | |
6d76dcf4 | 2014 | idx = hstate_index(h); |
a1e78772 | 2015 | /* |
d85f69b0 MK |
2016 | * Examine the region/reserve map to determine if the process |
2017 | * has a reservation for the page to be allocated. A return | |
2018 | * code of zero indicates a reservation exists (no change). | |
a1e78772 | 2019 | */ |
d85f69b0 MK |
2020 | map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); |
2021 | if (map_chg < 0) | |
76dcee75 | 2022 | return ERR_PTR(-ENOMEM); |
d85f69b0 MK |
2023 | |
2024 | /* | |
2025 | * Processes that did not create the mapping will have no | |
2026 | * reserves as indicated by the region/reserve map. Check | |
2027 | * that the allocation will not exceed the subpool limit. | |
2028 | * Allocations for MAP_NORESERVE mappings also need to be | |
2029 | * checked against any subpool limit. | |
2030 | */ | |
2031 | if (map_chg || avoid_reserve) { | |
2032 | gbl_chg = hugepage_subpool_get_pages(spool, 1); | |
2033 | if (gbl_chg < 0) { | |
feba16e2 | 2034 | vma_end_reservation(h, vma, addr); |
76dcee75 | 2035 | return ERR_PTR(-ENOSPC); |
5e911373 | 2036 | } |
1da177e4 | 2037 | |
d85f69b0 MK |
2038 | /* |
2039 | * Even though there was no reservation in the region/reserve | |
2040 | * map, there could be reservations associated with the | |
2041 | * subpool that can be used. This would be indicated if the | |
2042 | * return value of hugepage_subpool_get_pages() is zero. | |
2043 | * However, if avoid_reserve is specified we still avoid even | |
2044 | * the subpool reservations. | |
2045 | */ | |
2046 | if (avoid_reserve) | |
2047 | gbl_chg = 1; | |
2048 | } | |
2049 | ||
6d76dcf4 | 2050 | ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); |
8f34af6f JZ |
2051 | if (ret) |
2052 | goto out_subpool_put; | |
2053 | ||
1da177e4 | 2054 | spin_lock(&hugetlb_lock); |
d85f69b0 MK |
2055 | /* |
2056 | * glb_chg is passed to indicate whether or not a page must be taken | |
2057 | * from the global free pool (global change). gbl_chg == 0 indicates | |
2058 | * a reservation exists for the allocation. | |
2059 | */ | |
2060 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); | |
81a6fcae | 2061 | if (!page) { |
94ae8ba7 | 2062 | spin_unlock(&hugetlb_lock); |
0c397dae | 2063 | page = alloc_buddy_huge_page_with_mpol(h, vma, addr); |
8f34af6f JZ |
2064 | if (!page) |
2065 | goto out_uncharge_cgroup; | |
a88c7695 NH |
2066 | if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { |
2067 | SetPagePrivate(page); | |
2068 | h->resv_huge_pages--; | |
2069 | } | |
79dbb236 AK |
2070 | spin_lock(&hugetlb_lock); |
2071 | list_move(&page->lru, &h->hugepage_activelist); | |
81a6fcae | 2072 | /* Fall through */ |
68842c9b | 2073 | } |
81a6fcae JK |
2074 | hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); |
2075 | spin_unlock(&hugetlb_lock); | |
348ea204 | 2076 | |
90481622 | 2077 | set_page_private(page, (unsigned long)spool); |
90d8b7e6 | 2078 | |
d85f69b0 MK |
2079 | map_commit = vma_commit_reservation(h, vma, addr); |
2080 | if (unlikely(map_chg > map_commit)) { | |
33039678 MK |
2081 | /* |
2082 | * The page was added to the reservation map between | |
2083 | * vma_needs_reservation and vma_commit_reservation. | |
2084 | * This indicates a race with hugetlb_reserve_pages. | |
2085 | * Adjust for the subpool count incremented above AND | |
2086 | * in hugetlb_reserve_pages for the same page. Also, | |
2087 | * the reservation count added in hugetlb_reserve_pages | |
2088 | * no longer applies. | |
2089 | */ | |
2090 | long rsv_adjust; | |
2091 | ||
2092 | rsv_adjust = hugepage_subpool_put_pages(spool, 1); | |
2093 | hugetlb_acct_memory(h, -rsv_adjust); | |
2094 | } | |
90d8b7e6 | 2095 | return page; |
8f34af6f JZ |
2096 | |
2097 | out_uncharge_cgroup: | |
2098 | hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); | |
2099 | out_subpool_put: | |
d85f69b0 | 2100 | if (map_chg || avoid_reserve) |
8f34af6f | 2101 | hugepage_subpool_put_pages(spool, 1); |
feba16e2 | 2102 | vma_end_reservation(h, vma, addr); |
8f34af6f | 2103 | return ERR_PTR(-ENOSPC); |
b45b5bd6 DG |
2104 | } |
2105 | ||
e24a1307 AK |
2106 | int alloc_bootmem_huge_page(struct hstate *h) |
2107 | __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); | |
2108 | int __alloc_bootmem_huge_page(struct hstate *h) | |
aa888a74 AK |
2109 | { |
2110 | struct huge_bootmem_page *m; | |
b2261026 | 2111 | int nr_nodes, node; |
aa888a74 | 2112 | |
b2261026 | 2113 | for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { |
aa888a74 AK |
2114 | void *addr; |
2115 | ||
eb31d559 | 2116 | addr = memblock_alloc_try_nid_raw( |
8b89a116 | 2117 | huge_page_size(h), huge_page_size(h), |
97ad1087 | 2118 | 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); |
aa888a74 AK |
2119 | if (addr) { |
2120 | /* | |
2121 | * Use the beginning of the huge page to store the | |
2122 | * huge_bootmem_page struct (until gather_bootmem | |
2123 | * puts them into the mem_map). | |
2124 | */ | |
2125 | m = addr; | |
91f47662 | 2126 | goto found; |
aa888a74 | 2127 | } |
aa888a74 AK |
2128 | } |
2129 | return 0; | |
2130 | ||
2131 | found: | |
df994ead | 2132 | BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); |
aa888a74 | 2133 | /* Put them into a private list first because mem_map is not up yet */ |
330d6e48 | 2134 | INIT_LIST_HEAD(&m->list); |
aa888a74 AK |
2135 | list_add(&m->list, &huge_boot_pages); |
2136 | m->hstate = h; | |
2137 | return 1; | |
2138 | } | |
2139 | ||
d00181b9 KS |
2140 | static void __init prep_compound_huge_page(struct page *page, |
2141 | unsigned int order) | |
18229df5 AW |
2142 | { |
2143 | if (unlikely(order > (MAX_ORDER - 1))) | |
2144 | prep_compound_gigantic_page(page, order); | |
2145 | else | |
2146 | prep_compound_page(page, order); | |
2147 | } | |
2148 | ||
aa888a74 AK |
2149 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
2150 | static void __init gather_bootmem_prealloc(void) | |
2151 | { | |
2152 | struct huge_bootmem_page *m; | |
2153 | ||
2154 | list_for_each_entry(m, &huge_boot_pages, list) { | |
40d18ebf | 2155 | struct page *page = virt_to_page(m); |
aa888a74 | 2156 | struct hstate *h = m->hstate; |
ee8f248d | 2157 | |
aa888a74 | 2158 | WARN_ON(page_count(page) != 1); |
18229df5 | 2159 | prep_compound_huge_page(page, h->order); |
ef5a22be | 2160 | WARN_ON(PageReserved(page)); |
aa888a74 | 2161 | prep_new_huge_page(h, page, page_to_nid(page)); |
af0fb9df MH |
2162 | put_page(page); /* free it into the hugepage allocator */ |
2163 | ||
b0320c7b RA |
2164 | /* |
2165 | * If we had gigantic hugepages allocated at boot time, we need | |
2166 | * to restore the 'stolen' pages to totalram_pages in order to | |
2167 | * fix confusing memory reports from free(1) and another | |
2168 | * side-effects, like CommitLimit going negative. | |
2169 | */ | |
bae7f4ae | 2170 | if (hstate_is_gigantic(h)) |
3dcc0571 | 2171 | adjust_managed_page_count(page, 1 << h->order); |
520495fe | 2172 | cond_resched(); |
aa888a74 AK |
2173 | } |
2174 | } | |
2175 | ||
8faa8b07 | 2176 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
2177 | { |
2178 | unsigned long i; | |
a5516438 | 2179 | |
e5ff2159 | 2180 | for (i = 0; i < h->max_huge_pages; ++i) { |
bae7f4ae | 2181 | if (hstate_is_gigantic(h)) { |
aa888a74 AK |
2182 | if (!alloc_bootmem_huge_page(h)) |
2183 | break; | |
0c397dae | 2184 | } else if (!alloc_pool_huge_page(h, |
8cebfcd0 | 2185 | &node_states[N_MEMORY])) |
1da177e4 | 2186 | break; |
69ed779a | 2187 | cond_resched(); |
1da177e4 | 2188 | } |
d715cf80 LH |
2189 | if (i < h->max_huge_pages) { |
2190 | char buf[32]; | |
2191 | ||
c6247f72 | 2192 | string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); |
d715cf80 LH |
2193 | pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", |
2194 | h->max_huge_pages, buf, i); | |
2195 | h->max_huge_pages = i; | |
2196 | } | |
e5ff2159 AK |
2197 | } |
2198 | ||
2199 | static void __init hugetlb_init_hstates(void) | |
2200 | { | |
2201 | struct hstate *h; | |
2202 | ||
2203 | for_each_hstate(h) { | |
641844f5 NH |
2204 | if (minimum_order > huge_page_order(h)) |
2205 | minimum_order = huge_page_order(h); | |
2206 | ||
8faa8b07 | 2207 | /* oversize hugepages were init'ed in early boot */ |
bae7f4ae | 2208 | if (!hstate_is_gigantic(h)) |
8faa8b07 | 2209 | hugetlb_hstate_alloc_pages(h); |
e5ff2159 | 2210 | } |
641844f5 | 2211 | VM_BUG_ON(minimum_order == UINT_MAX); |
e5ff2159 AK |
2212 | } |
2213 | ||
2214 | static void __init report_hugepages(void) | |
2215 | { | |
2216 | struct hstate *h; | |
2217 | ||
2218 | for_each_hstate(h) { | |
4abd32db | 2219 | char buf[32]; |
c6247f72 MW |
2220 | |
2221 | string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); | |
ffb22af5 | 2222 | pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", |
c6247f72 | 2223 | buf, h->free_huge_pages); |
e5ff2159 AK |
2224 | } |
2225 | } | |
2226 | ||
1da177e4 | 2227 | #ifdef CONFIG_HIGHMEM |
6ae11b27 LS |
2228 | static void try_to_free_low(struct hstate *h, unsigned long count, |
2229 | nodemask_t *nodes_allowed) | |
1da177e4 | 2230 | { |
4415cc8d CL |
2231 | int i; |
2232 | ||
bae7f4ae | 2233 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
2234 | return; |
2235 | ||
6ae11b27 | 2236 | for_each_node_mask(i, *nodes_allowed) { |
1da177e4 | 2237 | struct page *page, *next; |
a5516438 AK |
2238 | struct list_head *freel = &h->hugepage_freelists[i]; |
2239 | list_for_each_entry_safe(page, next, freel, lru) { | |
2240 | if (count >= h->nr_huge_pages) | |
6b0c880d | 2241 | return; |
1da177e4 LT |
2242 | if (PageHighMem(page)) |
2243 | continue; | |
2244 | list_del(&page->lru); | |
e5ff2159 | 2245 | update_and_free_page(h, page); |
a5516438 AK |
2246 | h->free_huge_pages--; |
2247 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
2248 | } |
2249 | } | |
2250 | } | |
2251 | #else | |
6ae11b27 LS |
2252 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
2253 | nodemask_t *nodes_allowed) | |
1da177e4 LT |
2254 | { |
2255 | } | |
2256 | #endif | |
2257 | ||
20a0307c WF |
2258 | /* |
2259 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
2260 | * balanced by operating on them in a round-robin fashion. | |
2261 | * Returns 1 if an adjustment was made. | |
2262 | */ | |
6ae11b27 LS |
2263 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
2264 | int delta) | |
20a0307c | 2265 | { |
b2261026 | 2266 | int nr_nodes, node; |
20a0307c WF |
2267 | |
2268 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 2269 | |
b2261026 JK |
2270 | if (delta < 0) { |
2271 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
2272 | if (h->surplus_huge_pages_node[node]) | |
2273 | goto found; | |
e8c5c824 | 2274 | } |
b2261026 JK |
2275 | } else { |
2276 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | |
2277 | if (h->surplus_huge_pages_node[node] < | |
2278 | h->nr_huge_pages_node[node]) | |
2279 | goto found; | |
e8c5c824 | 2280 | } |
b2261026 JK |
2281 | } |
2282 | return 0; | |
20a0307c | 2283 | |
b2261026 JK |
2284 | found: |
2285 | h->surplus_huge_pages += delta; | |
2286 | h->surplus_huge_pages_node[node] += delta; | |
2287 | return 1; | |
20a0307c WF |
2288 | } |
2289 | ||
a5516438 | 2290 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
4eb0716e AG |
2291 | static int set_max_huge_pages(struct hstate *h, unsigned long count, |
2292 | nodemask_t *nodes_allowed) | |
1da177e4 | 2293 | { |
7893d1d5 | 2294 | unsigned long min_count, ret; |
1da177e4 | 2295 | |
4eb0716e AG |
2296 | spin_lock(&hugetlb_lock); |
2297 | ||
2298 | /* | |
2299 | * Gigantic pages runtime allocation depend on the capability for large | |
2300 | * page range allocation. | |
2301 | * If the system does not provide this feature, return an error when | |
2302 | * the user tries to allocate gigantic pages but let the user free the | |
2303 | * boottime allocated gigantic pages. | |
2304 | */ | |
2305 | if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { | |
2306 | if (count > persistent_huge_pages(h)) { | |
2307 | spin_unlock(&hugetlb_lock); | |
2308 | return -EINVAL; | |
2309 | } | |
2310 | /* Fall through to decrease pool */ | |
2311 | } | |
aa888a74 | 2312 | |
7893d1d5 AL |
2313 | /* |
2314 | * Increase the pool size | |
2315 | * First take pages out of surplus state. Then make up the | |
2316 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f | 2317 | * |
0c397dae | 2318 | * We might race with alloc_surplus_huge_page() here and be unable |
d1c3fb1f NA |
2319 | * to convert a surplus huge page to a normal huge page. That is |
2320 | * not critical, though, it just means the overall size of the | |
2321 | * pool might be one hugepage larger than it needs to be, but | |
2322 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 2323 | */ |
a5516438 | 2324 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
6ae11b27 | 2325 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
7893d1d5 AL |
2326 | break; |
2327 | } | |
2328 | ||
a5516438 | 2329 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
2330 | /* |
2331 | * If this allocation races such that we no longer need the | |
2332 | * page, free_huge_page will handle it by freeing the page | |
2333 | * and reducing the surplus. | |
2334 | */ | |
2335 | spin_unlock(&hugetlb_lock); | |
649920c6 JH |
2336 | |
2337 | /* yield cpu to avoid soft lockup */ | |
2338 | cond_resched(); | |
2339 | ||
0c397dae | 2340 | ret = alloc_pool_huge_page(h, nodes_allowed); |
7893d1d5 AL |
2341 | spin_lock(&hugetlb_lock); |
2342 | if (!ret) | |
2343 | goto out; | |
2344 | ||
536240f2 MG |
2345 | /* Bail for signals. Probably ctrl-c from user */ |
2346 | if (signal_pending(current)) | |
2347 | goto out; | |
7893d1d5 | 2348 | } |
7893d1d5 AL |
2349 | |
2350 | /* | |
2351 | * Decrease the pool size | |
2352 | * First return free pages to the buddy allocator (being careful | |
2353 | * to keep enough around to satisfy reservations). Then place | |
2354 | * pages into surplus state as needed so the pool will shrink | |
2355 | * to the desired size as pages become free. | |
d1c3fb1f NA |
2356 | * |
2357 | * By placing pages into the surplus state independent of the | |
2358 | * overcommit value, we are allowing the surplus pool size to | |
2359 | * exceed overcommit. There are few sane options here. Since | |
0c397dae | 2360 | * alloc_surplus_huge_page() is checking the global counter, |
d1c3fb1f NA |
2361 | * though, we'll note that we're not allowed to exceed surplus |
2362 | * and won't grow the pool anywhere else. Not until one of the | |
2363 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 2364 | */ |
a5516438 | 2365 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 2366 | min_count = max(count, min_count); |
6ae11b27 | 2367 | try_to_free_low(h, min_count, nodes_allowed); |
a5516438 | 2368 | while (min_count < persistent_huge_pages(h)) { |
6ae11b27 | 2369 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1da177e4 | 2370 | break; |
55f67141 | 2371 | cond_resched_lock(&hugetlb_lock); |
1da177e4 | 2372 | } |
a5516438 | 2373 | while (count < persistent_huge_pages(h)) { |
6ae11b27 | 2374 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
7893d1d5 AL |
2375 | break; |
2376 | } | |
2377 | out: | |
4eb0716e | 2378 | h->max_huge_pages = persistent_huge_pages(h); |
1da177e4 | 2379 | spin_unlock(&hugetlb_lock); |
4eb0716e AG |
2380 | |
2381 | return 0; | |
1da177e4 LT |
2382 | } |
2383 | ||
a3437870 NA |
2384 | #define HSTATE_ATTR_RO(_name) \ |
2385 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
2386 | ||
2387 | #define HSTATE_ATTR(_name) \ | |
2388 | static struct kobj_attribute _name##_attr = \ | |
2389 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
2390 | ||
2391 | static struct kobject *hugepages_kobj; | |
2392 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
2393 | ||
9a305230 LS |
2394 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); |
2395 | ||
2396 | static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) | |
a3437870 NA |
2397 | { |
2398 | int i; | |
9a305230 | 2399 | |
a3437870 | 2400 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
9a305230 LS |
2401 | if (hstate_kobjs[i] == kobj) { |
2402 | if (nidp) | |
2403 | *nidp = NUMA_NO_NODE; | |
a3437870 | 2404 | return &hstates[i]; |
9a305230 LS |
2405 | } |
2406 | ||
2407 | return kobj_to_node_hstate(kobj, nidp); | |
a3437870 NA |
2408 | } |
2409 | ||
06808b08 | 2410 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
a3437870 NA |
2411 | struct kobj_attribute *attr, char *buf) |
2412 | { | |
9a305230 LS |
2413 | struct hstate *h; |
2414 | unsigned long nr_huge_pages; | |
2415 | int nid; | |
2416 | ||
2417 | h = kobj_to_hstate(kobj, &nid); | |
2418 | if (nid == NUMA_NO_NODE) | |
2419 | nr_huge_pages = h->nr_huge_pages; | |
2420 | else | |
2421 | nr_huge_pages = h->nr_huge_pages_node[nid]; | |
2422 | ||
2423 | return sprintf(buf, "%lu\n", nr_huge_pages); | |
a3437870 | 2424 | } |
adbe8726 | 2425 | |
238d3c13 DR |
2426 | static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, |
2427 | struct hstate *h, int nid, | |
2428 | unsigned long count, size_t len) | |
a3437870 NA |
2429 | { |
2430 | int err; | |
bad44b5b | 2431 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); |
a3437870 | 2432 | |
4eb0716e | 2433 | if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) { |
adbe8726 EM |
2434 | err = -EINVAL; |
2435 | goto out; | |
2436 | } | |
2437 | ||
9a305230 LS |
2438 | if (nid == NUMA_NO_NODE) { |
2439 | /* | |
2440 | * global hstate attribute | |
2441 | */ | |
2442 | if (!(obey_mempolicy && | |
2443 | init_nodemask_of_mempolicy(nodes_allowed))) { | |
2444 | NODEMASK_FREE(nodes_allowed); | |
8cebfcd0 | 2445 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 LS |
2446 | } |
2447 | } else if (nodes_allowed) { | |
2448 | /* | |
2449 | * per node hstate attribute: adjust count to global, | |
2450 | * but restrict alloc/free to the specified node. | |
2451 | */ | |
2452 | count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; | |
2453 | init_nodemask_of_node(nodes_allowed, nid); | |
2454 | } else | |
8cebfcd0 | 2455 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 | 2456 | |
4eb0716e | 2457 | err = set_max_huge_pages(h, count, nodes_allowed); |
a3437870 | 2458 | |
4eb0716e | 2459 | out: |
8cebfcd0 | 2460 | if (nodes_allowed != &node_states[N_MEMORY]) |
06808b08 LS |
2461 | NODEMASK_FREE(nodes_allowed); |
2462 | ||
4eb0716e | 2463 | return err ? err : len; |
06808b08 LS |
2464 | } |
2465 | ||
238d3c13 DR |
2466 | static ssize_t nr_hugepages_store_common(bool obey_mempolicy, |
2467 | struct kobject *kobj, const char *buf, | |
2468 | size_t len) | |
2469 | { | |
2470 | struct hstate *h; | |
2471 | unsigned long count; | |
2472 | int nid; | |
2473 | int err; | |
2474 | ||
2475 | err = kstrtoul(buf, 10, &count); | |
2476 | if (err) | |
2477 | return err; | |
2478 | ||
2479 | h = kobj_to_hstate(kobj, &nid); | |
2480 | return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); | |
2481 | } | |
2482 | ||
06808b08 LS |
2483 | static ssize_t nr_hugepages_show(struct kobject *kobj, |
2484 | struct kobj_attribute *attr, char *buf) | |
2485 | { | |
2486 | return nr_hugepages_show_common(kobj, attr, buf); | |
2487 | } | |
2488 | ||
2489 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
2490 | struct kobj_attribute *attr, const char *buf, size_t len) | |
2491 | { | |
238d3c13 | 2492 | return nr_hugepages_store_common(false, kobj, buf, len); |
a3437870 NA |
2493 | } |
2494 | HSTATE_ATTR(nr_hugepages); | |
2495 | ||
06808b08 LS |
2496 | #ifdef CONFIG_NUMA |
2497 | ||
2498 | /* | |
2499 | * hstate attribute for optionally mempolicy-based constraint on persistent | |
2500 | * huge page alloc/free. | |
2501 | */ | |
2502 | static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, | |
2503 | struct kobj_attribute *attr, char *buf) | |
2504 | { | |
2505 | return nr_hugepages_show_common(kobj, attr, buf); | |
2506 | } | |
2507 | ||
2508 | static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, | |
2509 | struct kobj_attribute *attr, const char *buf, size_t len) | |
2510 | { | |
238d3c13 | 2511 | return nr_hugepages_store_common(true, kobj, buf, len); |
06808b08 LS |
2512 | } |
2513 | HSTATE_ATTR(nr_hugepages_mempolicy); | |
2514 | #endif | |
2515 | ||
2516 | ||
a3437870 NA |
2517 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
2518 | struct kobj_attribute *attr, char *buf) | |
2519 | { | |
9a305230 | 2520 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
2521 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); |
2522 | } | |
adbe8726 | 2523 | |
a3437870 NA |
2524 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, |
2525 | struct kobj_attribute *attr, const char *buf, size_t count) | |
2526 | { | |
2527 | int err; | |
2528 | unsigned long input; | |
9a305230 | 2529 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 | 2530 | |
bae7f4ae | 2531 | if (hstate_is_gigantic(h)) |
adbe8726 EM |
2532 | return -EINVAL; |
2533 | ||
3dbb95f7 | 2534 | err = kstrtoul(buf, 10, &input); |
a3437870 | 2535 | if (err) |
73ae31e5 | 2536 | return err; |
a3437870 NA |
2537 | |
2538 | spin_lock(&hugetlb_lock); | |
2539 | h->nr_overcommit_huge_pages = input; | |
2540 | spin_unlock(&hugetlb_lock); | |
2541 | ||
2542 | return count; | |
2543 | } | |
2544 | HSTATE_ATTR(nr_overcommit_hugepages); | |
2545 | ||
2546 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
2547 | struct kobj_attribute *attr, char *buf) | |
2548 | { | |
9a305230 LS |
2549 | struct hstate *h; |
2550 | unsigned long free_huge_pages; | |
2551 | int nid; | |
2552 | ||
2553 | h = kobj_to_hstate(kobj, &nid); | |
2554 | if (nid == NUMA_NO_NODE) | |
2555 | free_huge_pages = h->free_huge_pages; | |
2556 | else | |
2557 | free_huge_pages = h->free_huge_pages_node[nid]; | |
2558 | ||
2559 | return sprintf(buf, "%lu\n", free_huge_pages); | |
a3437870 NA |
2560 | } |
2561 | HSTATE_ATTR_RO(free_hugepages); | |
2562 | ||
2563 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
2564 | struct kobj_attribute *attr, char *buf) | |
2565 | { | |
9a305230 | 2566 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
2567 | return sprintf(buf, "%lu\n", h->resv_huge_pages); |
2568 | } | |
2569 | HSTATE_ATTR_RO(resv_hugepages); | |
2570 | ||
2571 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
2572 | struct kobj_attribute *attr, char *buf) | |
2573 | { | |
9a305230 LS |
2574 | struct hstate *h; |
2575 | unsigned long surplus_huge_pages; | |
2576 | int nid; | |
2577 | ||
2578 | h = kobj_to_hstate(kobj, &nid); | |
2579 | if (nid == NUMA_NO_NODE) | |
2580 | surplus_huge_pages = h->surplus_huge_pages; | |
2581 | else | |
2582 | surplus_huge_pages = h->surplus_huge_pages_node[nid]; | |
2583 | ||
2584 | return sprintf(buf, "%lu\n", surplus_huge_pages); | |
a3437870 NA |
2585 | } |
2586 | HSTATE_ATTR_RO(surplus_hugepages); | |
2587 | ||
2588 | static struct attribute *hstate_attrs[] = { | |
2589 | &nr_hugepages_attr.attr, | |
2590 | &nr_overcommit_hugepages_attr.attr, | |
2591 | &free_hugepages_attr.attr, | |
2592 | &resv_hugepages_attr.attr, | |
2593 | &surplus_hugepages_attr.attr, | |
06808b08 LS |
2594 | #ifdef CONFIG_NUMA |
2595 | &nr_hugepages_mempolicy_attr.attr, | |
2596 | #endif | |
a3437870 NA |
2597 | NULL, |
2598 | }; | |
2599 | ||
67e5ed96 | 2600 | static const struct attribute_group hstate_attr_group = { |
a3437870 NA |
2601 | .attrs = hstate_attrs, |
2602 | }; | |
2603 | ||
094e9539 JM |
2604 | static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, |
2605 | struct kobject **hstate_kobjs, | |
67e5ed96 | 2606 | const struct attribute_group *hstate_attr_group) |
a3437870 NA |
2607 | { |
2608 | int retval; | |
972dc4de | 2609 | int hi = hstate_index(h); |
a3437870 | 2610 | |
9a305230 LS |
2611 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
2612 | if (!hstate_kobjs[hi]) | |
a3437870 NA |
2613 | return -ENOMEM; |
2614 | ||
9a305230 | 2615 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
a3437870 | 2616 | if (retval) |
9a305230 | 2617 | kobject_put(hstate_kobjs[hi]); |
a3437870 NA |
2618 | |
2619 | return retval; | |
2620 | } | |
2621 | ||
2622 | static void __init hugetlb_sysfs_init(void) | |
2623 | { | |
2624 | struct hstate *h; | |
2625 | int err; | |
2626 | ||
2627 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
2628 | if (!hugepages_kobj) | |
2629 | return; | |
2630 | ||
2631 | for_each_hstate(h) { | |
9a305230 LS |
2632 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
2633 | hstate_kobjs, &hstate_attr_group); | |
a3437870 | 2634 | if (err) |
ffb22af5 | 2635 | pr_err("Hugetlb: Unable to add hstate %s", h->name); |
a3437870 NA |
2636 | } |
2637 | } | |
2638 | ||
9a305230 LS |
2639 | #ifdef CONFIG_NUMA |
2640 | ||
2641 | /* | |
2642 | * node_hstate/s - associate per node hstate attributes, via their kobjects, | |
10fbcf4c KS |
2643 | * with node devices in node_devices[] using a parallel array. The array |
2644 | * index of a node device or _hstate == node id. | |
2645 | * This is here to avoid any static dependency of the node device driver, in | |
9a305230 LS |
2646 | * the base kernel, on the hugetlb module. |
2647 | */ | |
2648 | struct node_hstate { | |
2649 | struct kobject *hugepages_kobj; | |
2650 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
2651 | }; | |
b4e289a6 | 2652 | static struct node_hstate node_hstates[MAX_NUMNODES]; |
9a305230 LS |
2653 | |
2654 | /* | |
10fbcf4c | 2655 | * A subset of global hstate attributes for node devices |
9a305230 LS |
2656 | */ |
2657 | static struct attribute *per_node_hstate_attrs[] = { | |
2658 | &nr_hugepages_attr.attr, | |
2659 | &free_hugepages_attr.attr, | |
2660 | &surplus_hugepages_attr.attr, | |
2661 | NULL, | |
2662 | }; | |
2663 | ||
67e5ed96 | 2664 | static const struct attribute_group per_node_hstate_attr_group = { |
9a305230 LS |
2665 | .attrs = per_node_hstate_attrs, |
2666 | }; | |
2667 | ||
2668 | /* | |
10fbcf4c | 2669 | * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. |
9a305230 LS |
2670 | * Returns node id via non-NULL nidp. |
2671 | */ | |
2672 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
2673 | { | |
2674 | int nid; | |
2675 | ||
2676 | for (nid = 0; nid < nr_node_ids; nid++) { | |
2677 | struct node_hstate *nhs = &node_hstates[nid]; | |
2678 | int i; | |
2679 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
2680 | if (nhs->hstate_kobjs[i] == kobj) { | |
2681 | if (nidp) | |
2682 | *nidp = nid; | |
2683 | return &hstates[i]; | |
2684 | } | |
2685 | } | |
2686 | ||
2687 | BUG(); | |
2688 | return NULL; | |
2689 | } | |
2690 | ||
2691 | /* | |
10fbcf4c | 2692 | * Unregister hstate attributes from a single node device. |
9a305230 LS |
2693 | * No-op if no hstate attributes attached. |
2694 | */ | |
3cd8b44f | 2695 | static void hugetlb_unregister_node(struct node *node) |
9a305230 LS |
2696 | { |
2697 | struct hstate *h; | |
10fbcf4c | 2698 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2699 | |
2700 | if (!nhs->hugepages_kobj) | |
9b5e5d0f | 2701 | return; /* no hstate attributes */ |
9a305230 | 2702 | |
972dc4de AK |
2703 | for_each_hstate(h) { |
2704 | int idx = hstate_index(h); | |
2705 | if (nhs->hstate_kobjs[idx]) { | |
2706 | kobject_put(nhs->hstate_kobjs[idx]); | |
2707 | nhs->hstate_kobjs[idx] = NULL; | |
9a305230 | 2708 | } |
972dc4de | 2709 | } |
9a305230 LS |
2710 | |
2711 | kobject_put(nhs->hugepages_kobj); | |
2712 | nhs->hugepages_kobj = NULL; | |
2713 | } | |
2714 | ||
9a305230 LS |
2715 | |
2716 | /* | |
10fbcf4c | 2717 | * Register hstate attributes for a single node device. |
9a305230 LS |
2718 | * No-op if attributes already registered. |
2719 | */ | |
3cd8b44f | 2720 | static void hugetlb_register_node(struct node *node) |
9a305230 LS |
2721 | { |
2722 | struct hstate *h; | |
10fbcf4c | 2723 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2724 | int err; |
2725 | ||
2726 | if (nhs->hugepages_kobj) | |
2727 | return; /* already allocated */ | |
2728 | ||
2729 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", | |
10fbcf4c | 2730 | &node->dev.kobj); |
9a305230 LS |
2731 | if (!nhs->hugepages_kobj) |
2732 | return; | |
2733 | ||
2734 | for_each_hstate(h) { | |
2735 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, | |
2736 | nhs->hstate_kobjs, | |
2737 | &per_node_hstate_attr_group); | |
2738 | if (err) { | |
ffb22af5 AM |
2739 | pr_err("Hugetlb: Unable to add hstate %s for node %d\n", |
2740 | h->name, node->dev.id); | |
9a305230 LS |
2741 | hugetlb_unregister_node(node); |
2742 | break; | |
2743 | } | |
2744 | } | |
2745 | } | |
2746 | ||
2747 | /* | |
9b5e5d0f | 2748 | * hugetlb init time: register hstate attributes for all registered node |
10fbcf4c KS |
2749 | * devices of nodes that have memory. All on-line nodes should have |
2750 | * registered their associated device by this time. | |
9a305230 | 2751 | */ |
7d9ca000 | 2752 | static void __init hugetlb_register_all_nodes(void) |
9a305230 LS |
2753 | { |
2754 | int nid; | |
2755 | ||
8cebfcd0 | 2756 | for_each_node_state(nid, N_MEMORY) { |
8732794b | 2757 | struct node *node = node_devices[nid]; |
10fbcf4c | 2758 | if (node->dev.id == nid) |
9a305230 LS |
2759 | hugetlb_register_node(node); |
2760 | } | |
2761 | ||
2762 | /* | |
10fbcf4c | 2763 | * Let the node device driver know we're here so it can |
9a305230 LS |
2764 | * [un]register hstate attributes on node hotplug. |
2765 | */ | |
2766 | register_hugetlbfs_with_node(hugetlb_register_node, | |
2767 | hugetlb_unregister_node); | |
2768 | } | |
2769 | #else /* !CONFIG_NUMA */ | |
2770 | ||
2771 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
2772 | { | |
2773 | BUG(); | |
2774 | if (nidp) | |
2775 | *nidp = -1; | |
2776 | return NULL; | |
2777 | } | |
2778 | ||
9a305230 LS |
2779 | static void hugetlb_register_all_nodes(void) { } |
2780 | ||
2781 | #endif | |
2782 | ||
a3437870 NA |
2783 | static int __init hugetlb_init(void) |
2784 | { | |
8382d914 DB |
2785 | int i; |
2786 | ||
457c1b27 | 2787 | if (!hugepages_supported()) |
0ef89d25 | 2788 | return 0; |
a3437870 | 2789 | |
e11bfbfc | 2790 | if (!size_to_hstate(default_hstate_size)) { |
d715cf80 LH |
2791 | if (default_hstate_size != 0) { |
2792 | pr_err("HugeTLB: unsupported default_hugepagesz %lu. Reverting to %lu\n", | |
2793 | default_hstate_size, HPAGE_SIZE); | |
2794 | } | |
2795 | ||
e11bfbfc NP |
2796 | default_hstate_size = HPAGE_SIZE; |
2797 | if (!size_to_hstate(default_hstate_size)) | |
2798 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 2799 | } |
972dc4de | 2800 | default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size)); |
f8b74815 VT |
2801 | if (default_hstate_max_huge_pages) { |
2802 | if (!default_hstate.max_huge_pages) | |
2803 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
2804 | } | |
a3437870 NA |
2805 | |
2806 | hugetlb_init_hstates(); | |
aa888a74 | 2807 | gather_bootmem_prealloc(); |
a3437870 NA |
2808 | report_hugepages(); |
2809 | ||
2810 | hugetlb_sysfs_init(); | |
9a305230 | 2811 | hugetlb_register_all_nodes(); |
7179e7bf | 2812 | hugetlb_cgroup_file_init(); |
9a305230 | 2813 | |
8382d914 DB |
2814 | #ifdef CONFIG_SMP |
2815 | num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); | |
2816 | #else | |
2817 | num_fault_mutexes = 1; | |
2818 | #endif | |
c672c7f2 | 2819 | hugetlb_fault_mutex_table = |
6da2ec56 KC |
2820 | kmalloc_array(num_fault_mutexes, sizeof(struct mutex), |
2821 | GFP_KERNEL); | |
c672c7f2 | 2822 | BUG_ON(!hugetlb_fault_mutex_table); |
8382d914 DB |
2823 | |
2824 | for (i = 0; i < num_fault_mutexes; i++) | |
c672c7f2 | 2825 | mutex_init(&hugetlb_fault_mutex_table[i]); |
a3437870 NA |
2826 | return 0; |
2827 | } | |
3e89e1c5 | 2828 | subsys_initcall(hugetlb_init); |
a3437870 NA |
2829 | |
2830 | /* Should be called on processing a hugepagesz=... option */ | |
9fee021d VT |
2831 | void __init hugetlb_bad_size(void) |
2832 | { | |
2833 | parsed_valid_hugepagesz = false; | |
2834 | } | |
2835 | ||
d00181b9 | 2836 | void __init hugetlb_add_hstate(unsigned int order) |
a3437870 NA |
2837 | { |
2838 | struct hstate *h; | |
8faa8b07 AK |
2839 | unsigned long i; |
2840 | ||
a3437870 | 2841 | if (size_to_hstate(PAGE_SIZE << order)) { |
598d8091 | 2842 | pr_warn("hugepagesz= specified twice, ignoring\n"); |
a3437870 NA |
2843 | return; |
2844 | } | |
47d38344 | 2845 | BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); |
a3437870 | 2846 | BUG_ON(order == 0); |
47d38344 | 2847 | h = &hstates[hugetlb_max_hstate++]; |
a3437870 NA |
2848 | h->order = order; |
2849 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
2850 | h->nr_huge_pages = 0; |
2851 | h->free_huge_pages = 0; | |
2852 | for (i = 0; i < MAX_NUMNODES; ++i) | |
2853 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
0edaecfa | 2854 | INIT_LIST_HEAD(&h->hugepage_activelist); |
54f18d35 AM |
2855 | h->next_nid_to_alloc = first_memory_node; |
2856 | h->next_nid_to_free = first_memory_node; | |
a3437870 NA |
2857 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
2858 | huge_page_size(h)/1024); | |
8faa8b07 | 2859 | |
a3437870 NA |
2860 | parsed_hstate = h; |
2861 | } | |
2862 | ||
e11bfbfc | 2863 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
2864 | { |
2865 | unsigned long *mhp; | |
8faa8b07 | 2866 | static unsigned long *last_mhp; |
a3437870 | 2867 | |
9fee021d VT |
2868 | if (!parsed_valid_hugepagesz) { |
2869 | pr_warn("hugepages = %s preceded by " | |
2870 | "an unsupported hugepagesz, ignoring\n", s); | |
2871 | parsed_valid_hugepagesz = true; | |
2872 | return 1; | |
2873 | } | |
a3437870 | 2874 | /* |
47d38344 | 2875 | * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet, |
a3437870 NA |
2876 | * so this hugepages= parameter goes to the "default hstate". |
2877 | */ | |
9fee021d | 2878 | else if (!hugetlb_max_hstate) |
a3437870 NA |
2879 | mhp = &default_hstate_max_huge_pages; |
2880 | else | |
2881 | mhp = &parsed_hstate->max_huge_pages; | |
2882 | ||
8faa8b07 | 2883 | if (mhp == last_mhp) { |
598d8091 | 2884 | pr_warn("hugepages= specified twice without interleaving hugepagesz=, ignoring\n"); |
8faa8b07 AK |
2885 | return 1; |
2886 | } | |
2887 | ||
a3437870 NA |
2888 | if (sscanf(s, "%lu", mhp) <= 0) |
2889 | *mhp = 0; | |
2890 | ||
8faa8b07 AK |
2891 | /* |
2892 | * Global state is always initialized later in hugetlb_init. | |
2893 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
2894 | * use the bootmem allocator. | |
2895 | */ | |
47d38344 | 2896 | if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) |
8faa8b07 AK |
2897 | hugetlb_hstate_alloc_pages(parsed_hstate); |
2898 | ||
2899 | last_mhp = mhp; | |
2900 | ||
a3437870 NA |
2901 | return 1; |
2902 | } | |
e11bfbfc NP |
2903 | __setup("hugepages=", hugetlb_nrpages_setup); |
2904 | ||
2905 | static int __init hugetlb_default_setup(char *s) | |
2906 | { | |
2907 | default_hstate_size = memparse(s, &s); | |
2908 | return 1; | |
2909 | } | |
2910 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 2911 | |
8a213460 NA |
2912 | static unsigned int cpuset_mems_nr(unsigned int *array) |
2913 | { | |
2914 | int node; | |
2915 | unsigned int nr = 0; | |
2916 | ||
2917 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
2918 | nr += array[node]; | |
2919 | ||
2920 | return nr; | |
2921 | } | |
2922 | ||
2923 | #ifdef CONFIG_SYSCTL | |
06808b08 LS |
2924 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
2925 | struct ctl_table *table, int write, | |
2926 | void __user *buffer, size_t *length, loff_t *ppos) | |
1da177e4 | 2927 | { |
e5ff2159 | 2928 | struct hstate *h = &default_hstate; |
238d3c13 | 2929 | unsigned long tmp = h->max_huge_pages; |
08d4a246 | 2930 | int ret; |
e5ff2159 | 2931 | |
457c1b27 | 2932 | if (!hugepages_supported()) |
86613628 | 2933 | return -EOPNOTSUPP; |
457c1b27 | 2934 | |
e5ff2159 AK |
2935 | table->data = &tmp; |
2936 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2937 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2938 | if (ret) | |
2939 | goto out; | |
e5ff2159 | 2940 | |
238d3c13 DR |
2941 | if (write) |
2942 | ret = __nr_hugepages_store_common(obey_mempolicy, h, | |
2943 | NUMA_NO_NODE, tmp, *length); | |
08d4a246 MH |
2944 | out: |
2945 | return ret; | |
1da177e4 | 2946 | } |
396faf03 | 2947 | |
06808b08 LS |
2948 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
2949 | void __user *buffer, size_t *length, loff_t *ppos) | |
2950 | { | |
2951 | ||
2952 | return hugetlb_sysctl_handler_common(false, table, write, | |
2953 | buffer, length, ppos); | |
2954 | } | |
2955 | ||
2956 | #ifdef CONFIG_NUMA | |
2957 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, | |
2958 | void __user *buffer, size_t *length, loff_t *ppos) | |
2959 | { | |
2960 | return hugetlb_sysctl_handler_common(true, table, write, | |
2961 | buffer, length, ppos); | |
2962 | } | |
2963 | #endif /* CONFIG_NUMA */ | |
2964 | ||
a3d0c6aa | 2965 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
8d65af78 | 2966 | void __user *buffer, |
a3d0c6aa NA |
2967 | size_t *length, loff_t *ppos) |
2968 | { | |
a5516438 | 2969 | struct hstate *h = &default_hstate; |
e5ff2159 | 2970 | unsigned long tmp; |
08d4a246 | 2971 | int ret; |
e5ff2159 | 2972 | |
457c1b27 | 2973 | if (!hugepages_supported()) |
86613628 | 2974 | return -EOPNOTSUPP; |
457c1b27 | 2975 | |
c033a93c | 2976 | tmp = h->nr_overcommit_huge_pages; |
e5ff2159 | 2977 | |
bae7f4ae | 2978 | if (write && hstate_is_gigantic(h)) |
adbe8726 EM |
2979 | return -EINVAL; |
2980 | ||
e5ff2159 AK |
2981 | table->data = &tmp; |
2982 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2983 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2984 | if (ret) | |
2985 | goto out; | |
e5ff2159 AK |
2986 | |
2987 | if (write) { | |
2988 | spin_lock(&hugetlb_lock); | |
2989 | h->nr_overcommit_huge_pages = tmp; | |
2990 | spin_unlock(&hugetlb_lock); | |
2991 | } | |
08d4a246 MH |
2992 | out: |
2993 | return ret; | |
a3d0c6aa NA |
2994 | } |
2995 | ||
1da177e4 LT |
2996 | #endif /* CONFIG_SYSCTL */ |
2997 | ||
e1759c21 | 2998 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 2999 | { |
fcb2b0c5 RG |
3000 | struct hstate *h; |
3001 | unsigned long total = 0; | |
3002 | ||
457c1b27 NA |
3003 | if (!hugepages_supported()) |
3004 | return; | |
fcb2b0c5 RG |
3005 | |
3006 | for_each_hstate(h) { | |
3007 | unsigned long count = h->nr_huge_pages; | |
3008 | ||
3009 | total += (PAGE_SIZE << huge_page_order(h)) * count; | |
3010 | ||
3011 | if (h == &default_hstate) | |
3012 | seq_printf(m, | |
3013 | "HugePages_Total: %5lu\n" | |
3014 | "HugePages_Free: %5lu\n" | |
3015 | "HugePages_Rsvd: %5lu\n" | |
3016 | "HugePages_Surp: %5lu\n" | |
3017 | "Hugepagesize: %8lu kB\n", | |
3018 | count, | |
3019 | h->free_huge_pages, | |
3020 | h->resv_huge_pages, | |
3021 | h->surplus_huge_pages, | |
3022 | (PAGE_SIZE << huge_page_order(h)) / 1024); | |
3023 | } | |
3024 | ||
3025 | seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); | |
1da177e4 LT |
3026 | } |
3027 | ||
3028 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
3029 | { | |
a5516438 | 3030 | struct hstate *h = &default_hstate; |
457c1b27 NA |
3031 | if (!hugepages_supported()) |
3032 | return 0; | |
1da177e4 LT |
3033 | return sprintf(buf, |
3034 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
3035 | "Node %d HugePages_Free: %5u\n" |
3036 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
3037 | nid, h->nr_huge_pages_node[nid], |
3038 | nid, h->free_huge_pages_node[nid], | |
3039 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
3040 | } |
3041 | ||
949f7ec5 DR |
3042 | void hugetlb_show_meminfo(void) |
3043 | { | |
3044 | struct hstate *h; | |
3045 | int nid; | |
3046 | ||
457c1b27 NA |
3047 | if (!hugepages_supported()) |
3048 | return; | |
3049 | ||
949f7ec5 DR |
3050 | for_each_node_state(nid, N_MEMORY) |
3051 | for_each_hstate(h) | |
3052 | pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", | |
3053 | nid, | |
3054 | h->nr_huge_pages_node[nid], | |
3055 | h->free_huge_pages_node[nid], | |
3056 | h->surplus_huge_pages_node[nid], | |
3057 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
3058 | } | |
3059 | ||
5d317b2b NH |
3060 | void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) |
3061 | { | |
3062 | seq_printf(m, "HugetlbPages:\t%8lu kB\n", | |
3063 | atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); | |
3064 | } | |
3065 | ||
1da177e4 LT |
3066 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
3067 | unsigned long hugetlb_total_pages(void) | |
3068 | { | |
d0028588 WL |
3069 | struct hstate *h; |
3070 | unsigned long nr_total_pages = 0; | |
3071 | ||
3072 | for_each_hstate(h) | |
3073 | nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); | |
3074 | return nr_total_pages; | |
1da177e4 | 3075 | } |
1da177e4 | 3076 | |
a5516438 | 3077 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
3078 | { |
3079 | int ret = -ENOMEM; | |
3080 | ||
3081 | spin_lock(&hugetlb_lock); | |
3082 | /* | |
3083 | * When cpuset is configured, it breaks the strict hugetlb page | |
3084 | * reservation as the accounting is done on a global variable. Such | |
3085 | * reservation is completely rubbish in the presence of cpuset because | |
3086 | * the reservation is not checked against page availability for the | |
3087 | * current cpuset. Application can still potentially OOM'ed by kernel | |
3088 | * with lack of free htlb page in cpuset that the task is in. | |
3089 | * Attempt to enforce strict accounting with cpuset is almost | |
3090 | * impossible (or too ugly) because cpuset is too fluid that | |
3091 | * task or memory node can be dynamically moved between cpusets. | |
3092 | * | |
3093 | * The change of semantics for shared hugetlb mapping with cpuset is | |
3094 | * undesirable. However, in order to preserve some of the semantics, | |
3095 | * we fall back to check against current free page availability as | |
3096 | * a best attempt and hopefully to minimize the impact of changing | |
3097 | * semantics that cpuset has. | |
3098 | */ | |
3099 | if (delta > 0) { | |
a5516438 | 3100 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
3101 | goto out; |
3102 | ||
a5516438 AK |
3103 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
3104 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
3105 | goto out; |
3106 | } | |
3107 | } | |
3108 | ||
3109 | ret = 0; | |
3110 | if (delta < 0) | |
a5516438 | 3111 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
3112 | |
3113 | out: | |
3114 | spin_unlock(&hugetlb_lock); | |
3115 | return ret; | |
3116 | } | |
3117 | ||
84afd99b AW |
3118 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
3119 | { | |
f522c3ac | 3120 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b AW |
3121 | |
3122 | /* | |
3123 | * This new VMA should share its siblings reservation map if present. | |
3124 | * The VMA will only ever have a valid reservation map pointer where | |
3125 | * it is being copied for another still existing VMA. As that VMA | |
25985edc | 3126 | * has a reference to the reservation map it cannot disappear until |
84afd99b AW |
3127 | * after this open call completes. It is therefore safe to take a |
3128 | * new reference here without additional locking. | |
3129 | */ | |
4e35f483 | 3130 | if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
f522c3ac | 3131 | kref_get(&resv->refs); |
84afd99b AW |
3132 | } |
3133 | ||
a1e78772 MG |
3134 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
3135 | { | |
a5516438 | 3136 | struct hstate *h = hstate_vma(vma); |
f522c3ac | 3137 | struct resv_map *resv = vma_resv_map(vma); |
90481622 | 3138 | struct hugepage_subpool *spool = subpool_vma(vma); |
4e35f483 | 3139 | unsigned long reserve, start, end; |
1c5ecae3 | 3140 | long gbl_reserve; |
84afd99b | 3141 | |
4e35f483 JK |
3142 | if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
3143 | return; | |
84afd99b | 3144 | |
4e35f483 JK |
3145 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
3146 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b | 3147 | |
4e35f483 | 3148 | reserve = (end - start) - region_count(resv, start, end); |
84afd99b | 3149 | |
4e35f483 JK |
3150 | kref_put(&resv->refs, resv_map_release); |
3151 | ||
3152 | if (reserve) { | |
1c5ecae3 MK |
3153 | /* |
3154 | * Decrement reserve counts. The global reserve count may be | |
3155 | * adjusted if the subpool has a minimum size. | |
3156 | */ | |
3157 | gbl_reserve = hugepage_subpool_put_pages(spool, reserve); | |
3158 | hugetlb_acct_memory(h, -gbl_reserve); | |
84afd99b | 3159 | } |
a1e78772 MG |
3160 | } |
3161 | ||
31383c68 DW |
3162 | static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) |
3163 | { | |
3164 | if (addr & ~(huge_page_mask(hstate_vma(vma)))) | |
3165 | return -EINVAL; | |
3166 | return 0; | |
3167 | } | |
3168 | ||
05ea8860 DW |
3169 | static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) |
3170 | { | |
3171 | struct hstate *hstate = hstate_vma(vma); | |
3172 | ||
3173 | return 1UL << huge_page_shift(hstate); | |
3174 | } | |
3175 | ||
1da177e4 LT |
3176 | /* |
3177 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
3178 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
3179 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
3180 | * this far. | |
3181 | */ | |
b3ec9f33 | 3182 | static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) |
1da177e4 LT |
3183 | { |
3184 | BUG(); | |
d0217ac0 | 3185 | return 0; |
1da177e4 LT |
3186 | } |
3187 | ||
eec3636a JC |
3188 | /* |
3189 | * When a new function is introduced to vm_operations_struct and added | |
3190 | * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. | |
3191 | * This is because under System V memory model, mappings created via | |
3192 | * shmget/shmat with "huge page" specified are backed by hugetlbfs files, | |
3193 | * their original vm_ops are overwritten with shm_vm_ops. | |
3194 | */ | |
f0f37e2f | 3195 | const struct vm_operations_struct hugetlb_vm_ops = { |
d0217ac0 | 3196 | .fault = hugetlb_vm_op_fault, |
84afd99b | 3197 | .open = hugetlb_vm_op_open, |
a1e78772 | 3198 | .close = hugetlb_vm_op_close, |
31383c68 | 3199 | .split = hugetlb_vm_op_split, |
05ea8860 | 3200 | .pagesize = hugetlb_vm_op_pagesize, |
1da177e4 LT |
3201 | }; |
3202 | ||
1e8f889b DG |
3203 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
3204 | int writable) | |
63551ae0 DG |
3205 | { |
3206 | pte_t entry; | |
3207 | ||
1e8f889b | 3208 | if (writable) { |
106c992a GS |
3209 | entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, |
3210 | vma->vm_page_prot))); | |
63551ae0 | 3211 | } else { |
106c992a GS |
3212 | entry = huge_pte_wrprotect(mk_huge_pte(page, |
3213 | vma->vm_page_prot)); | |
63551ae0 DG |
3214 | } |
3215 | entry = pte_mkyoung(entry); | |
3216 | entry = pte_mkhuge(entry); | |
d9ed9faa | 3217 | entry = arch_make_huge_pte(entry, vma, page, writable); |
63551ae0 DG |
3218 | |
3219 | return entry; | |
3220 | } | |
3221 | ||
1e8f889b DG |
3222 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
3223 | unsigned long address, pte_t *ptep) | |
3224 | { | |
3225 | pte_t entry; | |
3226 | ||
106c992a | 3227 | entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); |
32f84528 | 3228 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) |
4b3073e1 | 3229 | update_mmu_cache(vma, address, ptep); |
1e8f889b DG |
3230 | } |
3231 | ||
d5ed7444 | 3232 | bool is_hugetlb_entry_migration(pte_t pte) |
4a705fef NH |
3233 | { |
3234 | swp_entry_t swp; | |
3235 | ||
3236 | if (huge_pte_none(pte) || pte_present(pte)) | |
d5ed7444 | 3237 | return false; |
4a705fef NH |
3238 | swp = pte_to_swp_entry(pte); |
3239 | if (non_swap_entry(swp) && is_migration_entry(swp)) | |
d5ed7444 | 3240 | return true; |
4a705fef | 3241 | else |
d5ed7444 | 3242 | return false; |
4a705fef NH |
3243 | } |
3244 | ||
3245 | static int is_hugetlb_entry_hwpoisoned(pte_t pte) | |
3246 | { | |
3247 | swp_entry_t swp; | |
3248 | ||
3249 | if (huge_pte_none(pte) || pte_present(pte)) | |
3250 | return 0; | |
3251 | swp = pte_to_swp_entry(pte); | |
3252 | if (non_swap_entry(swp) && is_hwpoison_entry(swp)) | |
3253 | return 1; | |
3254 | else | |
3255 | return 0; | |
3256 | } | |
1e8f889b | 3257 | |
63551ae0 DG |
3258 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
3259 | struct vm_area_struct *vma) | |
3260 | { | |
5e41540c | 3261 | pte_t *src_pte, *dst_pte, entry, dst_entry; |
63551ae0 | 3262 | struct page *ptepage; |
1c59827d | 3263 | unsigned long addr; |
1e8f889b | 3264 | int cow; |
a5516438 AK |
3265 | struct hstate *h = hstate_vma(vma); |
3266 | unsigned long sz = huge_page_size(h); | |
ac46d4f3 | 3267 | struct mmu_notifier_range range; |
e8569dd2 | 3268 | int ret = 0; |
1e8f889b DG |
3269 | |
3270 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 3271 | |
ac46d4f3 JG |
3272 | if (cow) { |
3273 | mmu_notifier_range_init(&range, src, vma->vm_start, | |
3274 | vma->vm_end); | |
3275 | mmu_notifier_invalidate_range_start(&range); | |
3276 | } | |
e8569dd2 | 3277 | |
a5516438 | 3278 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
cb900f41 | 3279 | spinlock_t *src_ptl, *dst_ptl; |
7868a208 | 3280 | src_pte = huge_pte_offset(src, addr, sz); |
c74df32c HD |
3281 | if (!src_pte) |
3282 | continue; | |
a5516438 | 3283 | dst_pte = huge_pte_alloc(dst, addr, sz); |
e8569dd2 AS |
3284 | if (!dst_pte) { |
3285 | ret = -ENOMEM; | |
3286 | break; | |
3287 | } | |
c5c99429 | 3288 | |
5e41540c MK |
3289 | /* |
3290 | * If the pagetables are shared don't copy or take references. | |
3291 | * dst_pte == src_pte is the common case of src/dest sharing. | |
3292 | * | |
3293 | * However, src could have 'unshared' and dst shares with | |
3294 | * another vma. If dst_pte !none, this implies sharing. | |
3295 | * Check here before taking page table lock, and once again | |
3296 | * after taking the lock below. | |
3297 | */ | |
3298 | dst_entry = huge_ptep_get(dst_pte); | |
3299 | if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) | |
c5c99429 LW |
3300 | continue; |
3301 | ||
cb900f41 KS |
3302 | dst_ptl = huge_pte_lock(h, dst, dst_pte); |
3303 | src_ptl = huge_pte_lockptr(h, src, src_pte); | |
3304 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
4a705fef | 3305 | entry = huge_ptep_get(src_pte); |
5e41540c MK |
3306 | dst_entry = huge_ptep_get(dst_pte); |
3307 | if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { | |
3308 | /* | |
3309 | * Skip if src entry none. Also, skip in the | |
3310 | * unlikely case dst entry !none as this implies | |
3311 | * sharing with another vma. | |
3312 | */ | |
4a705fef NH |
3313 | ; |
3314 | } else if (unlikely(is_hugetlb_entry_migration(entry) || | |
3315 | is_hugetlb_entry_hwpoisoned(entry))) { | |
3316 | swp_entry_t swp_entry = pte_to_swp_entry(entry); | |
3317 | ||
3318 | if (is_write_migration_entry(swp_entry) && cow) { | |
3319 | /* | |
3320 | * COW mappings require pages in both | |
3321 | * parent and child to be set to read. | |
3322 | */ | |
3323 | make_migration_entry_read(&swp_entry); | |
3324 | entry = swp_entry_to_pte(swp_entry); | |
e5251fd4 PA |
3325 | set_huge_swap_pte_at(src, addr, src_pte, |
3326 | entry, sz); | |
4a705fef | 3327 | } |
e5251fd4 | 3328 | set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); |
4a705fef | 3329 | } else { |
34ee645e | 3330 | if (cow) { |
0f10851e JG |
3331 | /* |
3332 | * No need to notify as we are downgrading page | |
3333 | * table protection not changing it to point | |
3334 | * to a new page. | |
3335 | * | |
ad56b738 | 3336 | * See Documentation/vm/mmu_notifier.rst |
0f10851e | 3337 | */ |
7f2e9525 | 3338 | huge_ptep_set_wrprotect(src, addr, src_pte); |
34ee645e | 3339 | } |
0253d634 | 3340 | entry = huge_ptep_get(src_pte); |
1c59827d HD |
3341 | ptepage = pte_page(entry); |
3342 | get_page(ptepage); | |
53f9263b | 3343 | page_dup_rmap(ptepage, true); |
1c59827d | 3344 | set_huge_pte_at(dst, addr, dst_pte, entry); |
5d317b2b | 3345 | hugetlb_count_add(pages_per_huge_page(h), dst); |
1c59827d | 3346 | } |
cb900f41 KS |
3347 | spin_unlock(src_ptl); |
3348 | spin_unlock(dst_ptl); | |
63551ae0 | 3349 | } |
63551ae0 | 3350 | |
e8569dd2 | 3351 | if (cow) |
ac46d4f3 | 3352 | mmu_notifier_invalidate_range_end(&range); |
e8569dd2 AS |
3353 | |
3354 | return ret; | |
63551ae0 DG |
3355 | } |
3356 | ||
24669e58 AK |
3357 | void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, |
3358 | unsigned long start, unsigned long end, | |
3359 | struct page *ref_page) | |
63551ae0 DG |
3360 | { |
3361 | struct mm_struct *mm = vma->vm_mm; | |
3362 | unsigned long address; | |
c7546f8f | 3363 | pte_t *ptep; |
63551ae0 | 3364 | pte_t pte; |
cb900f41 | 3365 | spinlock_t *ptl; |
63551ae0 | 3366 | struct page *page; |
a5516438 AK |
3367 | struct hstate *h = hstate_vma(vma); |
3368 | unsigned long sz = huge_page_size(h); | |
ac46d4f3 | 3369 | struct mmu_notifier_range range; |
a5516438 | 3370 | |
63551ae0 | 3371 | WARN_ON(!is_vm_hugetlb_page(vma)); |
a5516438 AK |
3372 | BUG_ON(start & ~huge_page_mask(h)); |
3373 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 3374 | |
07e32661 AK |
3375 | /* |
3376 | * This is a hugetlb vma, all the pte entries should point | |
3377 | * to huge page. | |
3378 | */ | |
ed6a7935 | 3379 | tlb_change_page_size(tlb, sz); |
24669e58 | 3380 | tlb_start_vma(tlb, vma); |
dff11abe MK |
3381 | |
3382 | /* | |
3383 | * If sharing possible, alert mmu notifiers of worst case. | |
3384 | */ | |
ac46d4f3 JG |
3385 | mmu_notifier_range_init(&range, mm, start, end); |
3386 | adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); | |
3387 | mmu_notifier_invalidate_range_start(&range); | |
569f48b8 | 3388 | address = start; |
569f48b8 | 3389 | for (; address < end; address += sz) { |
7868a208 | 3390 | ptep = huge_pte_offset(mm, address, sz); |
4c887265 | 3391 | if (!ptep) |
c7546f8f DG |
3392 | continue; |
3393 | ||
cb900f41 | 3394 | ptl = huge_pte_lock(h, mm, ptep); |
31d49da5 AK |
3395 | if (huge_pmd_unshare(mm, &address, ptep)) { |
3396 | spin_unlock(ptl); | |
dff11abe MK |
3397 | /* |
3398 | * We just unmapped a page of PMDs by clearing a PUD. | |
3399 | * The caller's TLB flush range should cover this area. | |
3400 | */ | |
31d49da5 AK |
3401 | continue; |
3402 | } | |
39dde65c | 3403 | |
6629326b | 3404 | pte = huge_ptep_get(ptep); |
31d49da5 AK |
3405 | if (huge_pte_none(pte)) { |
3406 | spin_unlock(ptl); | |
3407 | continue; | |
3408 | } | |
6629326b HD |
3409 | |
3410 | /* | |
9fbc1f63 NH |
3411 | * Migrating hugepage or HWPoisoned hugepage is already |
3412 | * unmapped and its refcount is dropped, so just clear pte here. | |
6629326b | 3413 | */ |
9fbc1f63 | 3414 | if (unlikely(!pte_present(pte))) { |
9386fac3 | 3415 | huge_pte_clear(mm, address, ptep, sz); |
31d49da5 AK |
3416 | spin_unlock(ptl); |
3417 | continue; | |
8c4894c6 | 3418 | } |
6629326b HD |
3419 | |
3420 | page = pte_page(pte); | |
04f2cbe3 MG |
3421 | /* |
3422 | * If a reference page is supplied, it is because a specific | |
3423 | * page is being unmapped, not a range. Ensure the page we | |
3424 | * are about to unmap is the actual page of interest. | |
3425 | */ | |
3426 | if (ref_page) { | |
31d49da5 AK |
3427 | if (page != ref_page) { |
3428 | spin_unlock(ptl); | |
3429 | continue; | |
3430 | } | |
04f2cbe3 MG |
3431 | /* |
3432 | * Mark the VMA as having unmapped its page so that | |
3433 | * future faults in this VMA will fail rather than | |
3434 | * looking like data was lost | |
3435 | */ | |
3436 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
3437 | } | |
3438 | ||
c7546f8f | 3439 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
b528e4b6 | 3440 | tlb_remove_huge_tlb_entry(h, tlb, ptep, address); |
106c992a | 3441 | if (huge_pte_dirty(pte)) |
6649a386 | 3442 | set_page_dirty(page); |
9e81130b | 3443 | |
5d317b2b | 3444 | hugetlb_count_sub(pages_per_huge_page(h), mm); |
d281ee61 | 3445 | page_remove_rmap(page, true); |
31d49da5 | 3446 | |
cb900f41 | 3447 | spin_unlock(ptl); |
e77b0852 | 3448 | tlb_remove_page_size(tlb, page, huge_page_size(h)); |
31d49da5 AK |
3449 | /* |
3450 | * Bail out after unmapping reference page if supplied | |
3451 | */ | |
3452 | if (ref_page) | |
3453 | break; | |
fe1668ae | 3454 | } |
ac46d4f3 | 3455 | mmu_notifier_invalidate_range_end(&range); |
24669e58 | 3456 | tlb_end_vma(tlb, vma); |
1da177e4 | 3457 | } |
63551ae0 | 3458 | |
d833352a MG |
3459 | void __unmap_hugepage_range_final(struct mmu_gather *tlb, |
3460 | struct vm_area_struct *vma, unsigned long start, | |
3461 | unsigned long end, struct page *ref_page) | |
3462 | { | |
3463 | __unmap_hugepage_range(tlb, vma, start, end, ref_page); | |
3464 | ||
3465 | /* | |
3466 | * Clear this flag so that x86's huge_pmd_share page_table_shareable | |
3467 | * test will fail on a vma being torn down, and not grab a page table | |
3468 | * on its way out. We're lucky that the flag has such an appropriate | |
3469 | * name, and can in fact be safely cleared here. We could clear it | |
3470 | * before the __unmap_hugepage_range above, but all that's necessary | |
c8c06efa | 3471 | * is to clear it before releasing the i_mmap_rwsem. This works |
d833352a | 3472 | * because in the context this is called, the VMA is about to be |
c8c06efa | 3473 | * destroyed and the i_mmap_rwsem is held. |
d833352a MG |
3474 | */ |
3475 | vma->vm_flags &= ~VM_MAYSHARE; | |
3476 | } | |
3477 | ||
502717f4 | 3478 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 3479 | unsigned long end, struct page *ref_page) |
502717f4 | 3480 | { |
24669e58 AK |
3481 | struct mm_struct *mm; |
3482 | struct mmu_gather tlb; | |
dff11abe MK |
3483 | unsigned long tlb_start = start; |
3484 | unsigned long tlb_end = end; | |
3485 | ||
3486 | /* | |
3487 | * If shared PMDs were possibly used within this vma range, adjust | |
3488 | * start/end for worst case tlb flushing. | |
3489 | * Note that we can not be sure if PMDs are shared until we try to | |
3490 | * unmap pages. However, we want to make sure TLB flushing covers | |
3491 | * the largest possible range. | |
3492 | */ | |
3493 | adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end); | |
24669e58 AK |
3494 | |
3495 | mm = vma->vm_mm; | |
3496 | ||
dff11abe | 3497 | tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end); |
24669e58 | 3498 | __unmap_hugepage_range(&tlb, vma, start, end, ref_page); |
dff11abe | 3499 | tlb_finish_mmu(&tlb, tlb_start, tlb_end); |
502717f4 KC |
3500 | } |
3501 | ||
04f2cbe3 MG |
3502 | /* |
3503 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
3504 | * mappping it owns the reserve page for. The intention is to unmap the page | |
3505 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
3506 | * same region. | |
3507 | */ | |
2f4612af DB |
3508 | static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
3509 | struct page *page, unsigned long address) | |
04f2cbe3 | 3510 | { |
7526674d | 3511 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
3512 | struct vm_area_struct *iter_vma; |
3513 | struct address_space *mapping; | |
04f2cbe3 MG |
3514 | pgoff_t pgoff; |
3515 | ||
3516 | /* | |
3517 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
3518 | * from page cache lookup which is in HPAGE_SIZE units. | |
3519 | */ | |
7526674d | 3520 | address = address & huge_page_mask(h); |
36e4f20a MH |
3521 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + |
3522 | vma->vm_pgoff; | |
93c76a3d | 3523 | mapping = vma->vm_file->f_mapping; |
04f2cbe3 | 3524 | |
4eb2b1dc MG |
3525 | /* |
3526 | * Take the mapping lock for the duration of the table walk. As | |
3527 | * this mapping should be shared between all the VMAs, | |
3528 | * __unmap_hugepage_range() is called as the lock is already held | |
3529 | */ | |
83cde9e8 | 3530 | i_mmap_lock_write(mapping); |
6b2dbba8 | 3531 | vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { |
04f2cbe3 MG |
3532 | /* Do not unmap the current VMA */ |
3533 | if (iter_vma == vma) | |
3534 | continue; | |
3535 | ||
2f84a899 MG |
3536 | /* |
3537 | * Shared VMAs have their own reserves and do not affect | |
3538 | * MAP_PRIVATE accounting but it is possible that a shared | |
3539 | * VMA is using the same page so check and skip such VMAs. | |
3540 | */ | |
3541 | if (iter_vma->vm_flags & VM_MAYSHARE) | |
3542 | continue; | |
3543 | ||
04f2cbe3 MG |
3544 | /* |
3545 | * Unmap the page from other VMAs without their own reserves. | |
3546 | * They get marked to be SIGKILLed if they fault in these | |
3547 | * areas. This is because a future no-page fault on this VMA | |
3548 | * could insert a zeroed page instead of the data existing | |
3549 | * from the time of fork. This would look like data corruption | |
3550 | */ | |
3551 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
24669e58 AK |
3552 | unmap_hugepage_range(iter_vma, address, |
3553 | address + huge_page_size(h), page); | |
04f2cbe3 | 3554 | } |
83cde9e8 | 3555 | i_mmap_unlock_write(mapping); |
04f2cbe3 MG |
3556 | } |
3557 | ||
0fe6e20b NH |
3558 | /* |
3559 | * Hugetlb_cow() should be called with page lock of the original hugepage held. | |
ef009b25 MH |
3560 | * Called with hugetlb_instantiation_mutex held and pte_page locked so we |
3561 | * cannot race with other handlers or page migration. | |
3562 | * Keep the pte_same checks anyway to make transition from the mutex easier. | |
0fe6e20b | 3563 | */ |
2b740303 | 3564 | static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
974e6d66 | 3565 | unsigned long address, pte_t *ptep, |
3999f52e | 3566 | struct page *pagecache_page, spinlock_t *ptl) |
1e8f889b | 3567 | { |
3999f52e | 3568 | pte_t pte; |
a5516438 | 3569 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 3570 | struct page *old_page, *new_page; |
2b740303 SJ |
3571 | int outside_reserve = 0; |
3572 | vm_fault_t ret = 0; | |
974e6d66 | 3573 | unsigned long haddr = address & huge_page_mask(h); |
ac46d4f3 | 3574 | struct mmu_notifier_range range; |
1e8f889b | 3575 | |
3999f52e | 3576 | pte = huge_ptep_get(ptep); |
1e8f889b DG |
3577 | old_page = pte_page(pte); |
3578 | ||
04f2cbe3 | 3579 | retry_avoidcopy: |
1e8f889b DG |
3580 | /* If no-one else is actually using this page, avoid the copy |
3581 | * and just make the page writable */ | |
37a2140d | 3582 | if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { |
5a49973d | 3583 | page_move_anon_rmap(old_page, vma); |
5b7a1d40 | 3584 | set_huge_ptep_writable(vma, haddr, ptep); |
83c54070 | 3585 | return 0; |
1e8f889b DG |
3586 | } |
3587 | ||
04f2cbe3 MG |
3588 | /* |
3589 | * If the process that created a MAP_PRIVATE mapping is about to | |
3590 | * perform a COW due to a shared page count, attempt to satisfy | |
3591 | * the allocation without using the existing reserves. The pagecache | |
3592 | * page is used to determine if the reserve at this address was | |
3593 | * consumed or not. If reserves were used, a partial faulted mapping | |
3594 | * at the time of fork() could consume its reserves on COW instead | |
3595 | * of the full address range. | |
3596 | */ | |
5944d011 | 3597 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
04f2cbe3 MG |
3598 | old_page != pagecache_page) |
3599 | outside_reserve = 1; | |
3600 | ||
09cbfeaf | 3601 | get_page(old_page); |
b76c8cfb | 3602 | |
ad4404a2 DB |
3603 | /* |
3604 | * Drop page table lock as buddy allocator may be called. It will | |
3605 | * be acquired again before returning to the caller, as expected. | |
3606 | */ | |
cb900f41 | 3607 | spin_unlock(ptl); |
5b7a1d40 | 3608 | new_page = alloc_huge_page(vma, haddr, outside_reserve); |
1e8f889b | 3609 | |
2fc39cec | 3610 | if (IS_ERR(new_page)) { |
04f2cbe3 MG |
3611 | /* |
3612 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
3613 | * it is due to references held by a child and an insufficient | |
3614 | * huge page pool. To guarantee the original mappers | |
3615 | * reliability, unmap the page from child processes. The child | |
3616 | * may get SIGKILLed if it later faults. | |
3617 | */ | |
3618 | if (outside_reserve) { | |
09cbfeaf | 3619 | put_page(old_page); |
04f2cbe3 | 3620 | BUG_ON(huge_pte_none(pte)); |
5b7a1d40 | 3621 | unmap_ref_private(mm, vma, old_page, haddr); |
2f4612af DB |
3622 | BUG_ON(huge_pte_none(pte)); |
3623 | spin_lock(ptl); | |
5b7a1d40 | 3624 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
2f4612af DB |
3625 | if (likely(ptep && |
3626 | pte_same(huge_ptep_get(ptep), pte))) | |
3627 | goto retry_avoidcopy; | |
3628 | /* | |
3629 | * race occurs while re-acquiring page table | |
3630 | * lock, and our job is done. | |
3631 | */ | |
3632 | return 0; | |
04f2cbe3 MG |
3633 | } |
3634 | ||
2b740303 | 3635 | ret = vmf_error(PTR_ERR(new_page)); |
ad4404a2 | 3636 | goto out_release_old; |
1e8f889b DG |
3637 | } |
3638 | ||
0fe6e20b NH |
3639 | /* |
3640 | * When the original hugepage is shared one, it does not have | |
3641 | * anon_vma prepared. | |
3642 | */ | |
44e2aa93 | 3643 | if (unlikely(anon_vma_prepare(vma))) { |
ad4404a2 DB |
3644 | ret = VM_FAULT_OOM; |
3645 | goto out_release_all; | |
44e2aa93 | 3646 | } |
0fe6e20b | 3647 | |
974e6d66 | 3648 | copy_user_huge_page(new_page, old_page, address, vma, |
47ad8475 | 3649 | pages_per_huge_page(h)); |
0ed361de | 3650 | __SetPageUptodate(new_page); |
1e8f889b | 3651 | |
ac46d4f3 JG |
3652 | mmu_notifier_range_init(&range, mm, haddr, haddr + huge_page_size(h)); |
3653 | mmu_notifier_invalidate_range_start(&range); | |
ad4404a2 | 3654 | |
b76c8cfb | 3655 | /* |
cb900f41 | 3656 | * Retake the page table lock to check for racing updates |
b76c8cfb LW |
3657 | * before the page tables are altered |
3658 | */ | |
cb900f41 | 3659 | spin_lock(ptl); |
5b7a1d40 | 3660 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
a9af0c5d | 3661 | if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { |
07443a85 JK |
3662 | ClearPagePrivate(new_page); |
3663 | ||
1e8f889b | 3664 | /* Break COW */ |
5b7a1d40 | 3665 | huge_ptep_clear_flush(vma, haddr, ptep); |
ac46d4f3 | 3666 | mmu_notifier_invalidate_range(mm, range.start, range.end); |
5b7a1d40 | 3667 | set_huge_pte_at(mm, haddr, ptep, |
1e8f889b | 3668 | make_huge_pte(vma, new_page, 1)); |
d281ee61 | 3669 | page_remove_rmap(old_page, true); |
5b7a1d40 | 3670 | hugepage_add_new_anon_rmap(new_page, vma, haddr); |
cb6acd01 | 3671 | set_page_huge_active(new_page); |
1e8f889b DG |
3672 | /* Make the old page be freed below */ |
3673 | new_page = old_page; | |
3674 | } | |
cb900f41 | 3675 | spin_unlock(ptl); |
ac46d4f3 | 3676 | mmu_notifier_invalidate_range_end(&range); |
ad4404a2 | 3677 | out_release_all: |
5b7a1d40 | 3678 | restore_reserve_on_error(h, vma, haddr, new_page); |
09cbfeaf | 3679 | put_page(new_page); |
ad4404a2 | 3680 | out_release_old: |
09cbfeaf | 3681 | put_page(old_page); |
8312034f | 3682 | |
ad4404a2 DB |
3683 | spin_lock(ptl); /* Caller expects lock to be held */ |
3684 | return ret; | |
1e8f889b DG |
3685 | } |
3686 | ||
04f2cbe3 | 3687 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
3688 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
3689 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
3690 | { |
3691 | struct address_space *mapping; | |
e7c4b0bf | 3692 | pgoff_t idx; |
04f2cbe3 MG |
3693 | |
3694 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 3695 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
3696 | |
3697 | return find_lock_page(mapping, idx); | |
3698 | } | |
3699 | ||
3ae77f43 HD |
3700 | /* |
3701 | * Return whether there is a pagecache page to back given address within VMA. | |
3702 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. | |
3703 | */ | |
3704 | static bool hugetlbfs_pagecache_present(struct hstate *h, | |
2a15efc9 HD |
3705 | struct vm_area_struct *vma, unsigned long address) |
3706 | { | |
3707 | struct address_space *mapping; | |
3708 | pgoff_t idx; | |
3709 | struct page *page; | |
3710 | ||
3711 | mapping = vma->vm_file->f_mapping; | |
3712 | idx = vma_hugecache_offset(h, vma, address); | |
3713 | ||
3714 | page = find_get_page(mapping, idx); | |
3715 | if (page) | |
3716 | put_page(page); | |
3717 | return page != NULL; | |
3718 | } | |
3719 | ||
ab76ad54 MK |
3720 | int huge_add_to_page_cache(struct page *page, struct address_space *mapping, |
3721 | pgoff_t idx) | |
3722 | { | |
3723 | struct inode *inode = mapping->host; | |
3724 | struct hstate *h = hstate_inode(inode); | |
3725 | int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
3726 | ||
3727 | if (err) | |
3728 | return err; | |
3729 | ClearPagePrivate(page); | |
3730 | ||
22146c3c MK |
3731 | /* |
3732 | * set page dirty so that it will not be removed from cache/file | |
3733 | * by non-hugetlbfs specific code paths. | |
3734 | */ | |
3735 | set_page_dirty(page); | |
3736 | ||
ab76ad54 MK |
3737 | spin_lock(&inode->i_lock); |
3738 | inode->i_blocks += blocks_per_huge_page(h); | |
3739 | spin_unlock(&inode->i_lock); | |
3740 | return 0; | |
3741 | } | |
3742 | ||
2b740303 SJ |
3743 | static vm_fault_t hugetlb_no_page(struct mm_struct *mm, |
3744 | struct vm_area_struct *vma, | |
3745 | struct address_space *mapping, pgoff_t idx, | |
3746 | unsigned long address, pte_t *ptep, unsigned int flags) | |
ac9b9c66 | 3747 | { |
a5516438 | 3748 | struct hstate *h = hstate_vma(vma); |
2b740303 | 3749 | vm_fault_t ret = VM_FAULT_SIGBUS; |
409eb8c2 | 3750 | int anon_rmap = 0; |
4c887265 | 3751 | unsigned long size; |
4c887265 | 3752 | struct page *page; |
1e8f889b | 3753 | pte_t new_pte; |
cb900f41 | 3754 | spinlock_t *ptl; |
285b8dca | 3755 | unsigned long haddr = address & huge_page_mask(h); |
cb6acd01 | 3756 | bool new_page = false; |
4c887265 | 3757 | |
04f2cbe3 MG |
3758 | /* |
3759 | * Currently, we are forced to kill the process in the event the | |
3760 | * original mapper has unmapped pages from the child due to a failed | |
25985edc | 3761 | * COW. Warn that such a situation has occurred as it may not be obvious |
04f2cbe3 MG |
3762 | */ |
3763 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
910154d5 | 3764 | pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", |
ffb22af5 | 3765 | current->pid); |
04f2cbe3 MG |
3766 | return ret; |
3767 | } | |
3768 | ||
4c887265 | 3769 | /* |
e7c58097 MK |
3770 | * Use page lock to guard against racing truncation |
3771 | * before we get page_table_lock. | |
4c887265 | 3772 | */ |
6bda666a CL |
3773 | retry: |
3774 | page = find_lock_page(mapping, idx); | |
3775 | if (!page) { | |
e7c58097 MK |
3776 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
3777 | if (idx >= size) | |
3778 | goto out; | |
3779 | ||
1a1aad8a MK |
3780 | /* |
3781 | * Check for page in userfault range | |
3782 | */ | |
3783 | if (userfaultfd_missing(vma)) { | |
3784 | u32 hash; | |
3785 | struct vm_fault vmf = { | |
3786 | .vma = vma, | |
285b8dca | 3787 | .address = haddr, |
1a1aad8a MK |
3788 | .flags = flags, |
3789 | /* | |
3790 | * Hard to debug if it ends up being | |
3791 | * used by a callee that assumes | |
3792 | * something about the other | |
3793 | * uninitialized fields... same as in | |
3794 | * memory.c | |
3795 | */ | |
3796 | }; | |
3797 | ||
3798 | /* | |
ddeaab32 MK |
3799 | * hugetlb_fault_mutex must be dropped before |
3800 | * handling userfault. Reacquire after handling | |
3801 | * fault to make calling code simpler. | |
1a1aad8a MK |
3802 | */ |
3803 | hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, | |
285b8dca | 3804 | idx, haddr); |
1a1aad8a MK |
3805 | mutex_unlock(&hugetlb_fault_mutex_table[hash]); |
3806 | ret = handle_userfault(&vmf, VM_UFFD_MISSING); | |
3807 | mutex_lock(&hugetlb_fault_mutex_table[hash]); | |
3808 | goto out; | |
3809 | } | |
3810 | ||
285b8dca | 3811 | page = alloc_huge_page(vma, haddr, 0); |
2fc39cec | 3812 | if (IS_ERR(page)) { |
2b740303 | 3813 | ret = vmf_error(PTR_ERR(page)); |
6bda666a CL |
3814 | goto out; |
3815 | } | |
47ad8475 | 3816 | clear_huge_page(page, address, pages_per_huge_page(h)); |
0ed361de | 3817 | __SetPageUptodate(page); |
cb6acd01 | 3818 | new_page = true; |
ac9b9c66 | 3819 | |
f83a275d | 3820 | if (vma->vm_flags & VM_MAYSHARE) { |
ab76ad54 | 3821 | int err = huge_add_to_page_cache(page, mapping, idx); |
6bda666a CL |
3822 | if (err) { |
3823 | put_page(page); | |
6bda666a CL |
3824 | if (err == -EEXIST) |
3825 | goto retry; | |
3826 | goto out; | |
3827 | } | |
23be7468 | 3828 | } else { |
6bda666a | 3829 | lock_page(page); |
0fe6e20b NH |
3830 | if (unlikely(anon_vma_prepare(vma))) { |
3831 | ret = VM_FAULT_OOM; | |
3832 | goto backout_unlocked; | |
3833 | } | |
409eb8c2 | 3834 | anon_rmap = 1; |
23be7468 | 3835 | } |
0fe6e20b | 3836 | } else { |
998b4382 NH |
3837 | /* |
3838 | * If memory error occurs between mmap() and fault, some process | |
3839 | * don't have hwpoisoned swap entry for errored virtual address. | |
3840 | * So we need to block hugepage fault by PG_hwpoison bit check. | |
3841 | */ | |
3842 | if (unlikely(PageHWPoison(page))) { | |
32f84528 | 3843 | ret = VM_FAULT_HWPOISON | |
972dc4de | 3844 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
998b4382 NH |
3845 | goto backout_unlocked; |
3846 | } | |
6bda666a | 3847 | } |
1e8f889b | 3848 | |
57303d80 AW |
3849 | /* |
3850 | * If we are going to COW a private mapping later, we examine the | |
3851 | * pending reservations for this page now. This will ensure that | |
3852 | * any allocations necessary to record that reservation occur outside | |
3853 | * the spinlock. | |
3854 | */ | |
5e911373 | 3855 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
285b8dca | 3856 | if (vma_needs_reservation(h, vma, haddr) < 0) { |
2b26736c AW |
3857 | ret = VM_FAULT_OOM; |
3858 | goto backout_unlocked; | |
3859 | } | |
5e911373 | 3860 | /* Just decrements count, does not deallocate */ |
285b8dca | 3861 | vma_end_reservation(h, vma, haddr); |
5e911373 | 3862 | } |
57303d80 | 3863 | |
8bea8052 | 3864 | ptl = huge_pte_lock(h, mm, ptep); |
e7c58097 MK |
3865 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
3866 | if (idx >= size) | |
3867 | goto backout; | |
4c887265 | 3868 | |
83c54070 | 3869 | ret = 0; |
7f2e9525 | 3870 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
3871 | goto backout; |
3872 | ||
07443a85 JK |
3873 | if (anon_rmap) { |
3874 | ClearPagePrivate(page); | |
285b8dca | 3875 | hugepage_add_new_anon_rmap(page, vma, haddr); |
ac714904 | 3876 | } else |
53f9263b | 3877 | page_dup_rmap(page, true); |
1e8f889b DG |
3878 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
3879 | && (vma->vm_flags & VM_SHARED))); | |
285b8dca | 3880 | set_huge_pte_at(mm, haddr, ptep, new_pte); |
1e8f889b | 3881 | |
5d317b2b | 3882 | hugetlb_count_add(pages_per_huge_page(h), mm); |
788c7df4 | 3883 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 3884 | /* Optimization, do the COW without a second fault */ |
974e6d66 | 3885 | ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); |
1e8f889b DG |
3886 | } |
3887 | ||
cb900f41 | 3888 | spin_unlock(ptl); |
cb6acd01 MK |
3889 | |
3890 | /* | |
3891 | * Only make newly allocated pages active. Existing pages found | |
3892 | * in the pagecache could be !page_huge_active() if they have been | |
3893 | * isolated for migration. | |
3894 | */ | |
3895 | if (new_page) | |
3896 | set_page_huge_active(page); | |
3897 | ||
4c887265 AL |
3898 | unlock_page(page); |
3899 | out: | |
ac9b9c66 | 3900 | return ret; |
4c887265 AL |
3901 | |
3902 | backout: | |
cb900f41 | 3903 | spin_unlock(ptl); |
2b26736c | 3904 | backout_unlocked: |
4c887265 | 3905 | unlock_page(page); |
285b8dca | 3906 | restore_reserve_on_error(h, vma, haddr, page); |
4c887265 AL |
3907 | put_page(page); |
3908 | goto out; | |
ac9b9c66 HD |
3909 | } |
3910 | ||
8382d914 | 3911 | #ifdef CONFIG_SMP |
c672c7f2 | 3912 | u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm, |
8382d914 DB |
3913 | struct vm_area_struct *vma, |
3914 | struct address_space *mapping, | |
3915 | pgoff_t idx, unsigned long address) | |
3916 | { | |
3917 | unsigned long key[2]; | |
3918 | u32 hash; | |
3919 | ||
3920 | if (vma->vm_flags & VM_SHARED) { | |
3921 | key[0] = (unsigned long) mapping; | |
3922 | key[1] = idx; | |
3923 | } else { | |
3924 | key[0] = (unsigned long) mm; | |
3925 | key[1] = address >> huge_page_shift(h); | |
3926 | } | |
3927 | ||
3928 | hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0); | |
3929 | ||
3930 | return hash & (num_fault_mutexes - 1); | |
3931 | } | |
3932 | #else | |
3933 | /* | |
3934 | * For uniprocesor systems we always use a single mutex, so just | |
3935 | * return 0 and avoid the hashing overhead. | |
3936 | */ | |
c672c7f2 | 3937 | u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm, |
8382d914 DB |
3938 | struct vm_area_struct *vma, |
3939 | struct address_space *mapping, | |
3940 | pgoff_t idx, unsigned long address) | |
3941 | { | |
3942 | return 0; | |
3943 | } | |
3944 | #endif | |
3945 | ||
2b740303 | 3946 | vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 3947 | unsigned long address, unsigned int flags) |
86e5216f | 3948 | { |
8382d914 | 3949 | pte_t *ptep, entry; |
cb900f41 | 3950 | spinlock_t *ptl; |
2b740303 | 3951 | vm_fault_t ret; |
8382d914 DB |
3952 | u32 hash; |
3953 | pgoff_t idx; | |
0fe6e20b | 3954 | struct page *page = NULL; |
57303d80 | 3955 | struct page *pagecache_page = NULL; |
a5516438 | 3956 | struct hstate *h = hstate_vma(vma); |
8382d914 | 3957 | struct address_space *mapping; |
0f792cf9 | 3958 | int need_wait_lock = 0; |
285b8dca | 3959 | unsigned long haddr = address & huge_page_mask(h); |
86e5216f | 3960 | |
285b8dca | 3961 | ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); |
fd6a03ed NH |
3962 | if (ptep) { |
3963 | entry = huge_ptep_get(ptep); | |
290408d4 | 3964 | if (unlikely(is_hugetlb_entry_migration(entry))) { |
cb900f41 | 3965 | migration_entry_wait_huge(vma, mm, ptep); |
290408d4 NH |
3966 | return 0; |
3967 | } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) | |
32f84528 | 3968 | return VM_FAULT_HWPOISON_LARGE | |
972dc4de | 3969 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
ddeaab32 MK |
3970 | } else { |
3971 | ptep = huge_pte_alloc(mm, haddr, huge_page_size(h)); | |
3972 | if (!ptep) | |
3973 | return VM_FAULT_OOM; | |
fd6a03ed NH |
3974 | } |
3975 | ||
8382d914 | 3976 | mapping = vma->vm_file->f_mapping; |
ddeaab32 | 3977 | idx = vma_hugecache_offset(h, vma, haddr); |
8382d914 | 3978 | |
3935baa9 DG |
3979 | /* |
3980 | * Serialize hugepage allocation and instantiation, so that we don't | |
3981 | * get spurious allocation failures if two CPUs race to instantiate | |
3982 | * the same page in the page cache. | |
3983 | */ | |
285b8dca | 3984 | hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, haddr); |
c672c7f2 | 3985 | mutex_lock(&hugetlb_fault_mutex_table[hash]); |
8382d914 | 3986 | |
7f2e9525 GS |
3987 | entry = huge_ptep_get(ptep); |
3988 | if (huge_pte_none(entry)) { | |
8382d914 | 3989 | ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); |
b4d1d99f | 3990 | goto out_mutex; |
3935baa9 | 3991 | } |
86e5216f | 3992 | |
83c54070 | 3993 | ret = 0; |
1e8f889b | 3994 | |
0f792cf9 NH |
3995 | /* |
3996 | * entry could be a migration/hwpoison entry at this point, so this | |
3997 | * check prevents the kernel from going below assuming that we have | |
3998 | * a active hugepage in pagecache. This goto expects the 2nd page fault, | |
3999 | * and is_hugetlb_entry_(migration|hwpoisoned) check will properly | |
4000 | * handle it. | |
4001 | */ | |
4002 | if (!pte_present(entry)) | |
4003 | goto out_mutex; | |
4004 | ||
57303d80 AW |
4005 | /* |
4006 | * If we are going to COW the mapping later, we examine the pending | |
4007 | * reservations for this page now. This will ensure that any | |
4008 | * allocations necessary to record that reservation occur outside the | |
4009 | * spinlock. For private mappings, we also lookup the pagecache | |
4010 | * page now as it is used to determine if a reservation has been | |
4011 | * consumed. | |
4012 | */ | |
106c992a | 4013 | if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { |
285b8dca | 4014 | if (vma_needs_reservation(h, vma, haddr) < 0) { |
2b26736c | 4015 | ret = VM_FAULT_OOM; |
b4d1d99f | 4016 | goto out_mutex; |
2b26736c | 4017 | } |
5e911373 | 4018 | /* Just decrements count, does not deallocate */ |
285b8dca | 4019 | vma_end_reservation(h, vma, haddr); |
57303d80 | 4020 | |
f83a275d | 4021 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 | 4022 | pagecache_page = hugetlbfs_pagecache_page(h, |
285b8dca | 4023 | vma, haddr); |
57303d80 AW |
4024 | } |
4025 | ||
0f792cf9 NH |
4026 | ptl = huge_pte_lock(h, mm, ptep); |
4027 | ||
4028 | /* Check for a racing update before calling hugetlb_cow */ | |
4029 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) | |
4030 | goto out_ptl; | |
4031 | ||
56c9cfb1 NH |
4032 | /* |
4033 | * hugetlb_cow() requires page locks of pte_page(entry) and | |
4034 | * pagecache_page, so here we need take the former one | |
4035 | * when page != pagecache_page or !pagecache_page. | |
56c9cfb1 NH |
4036 | */ |
4037 | page = pte_page(entry); | |
4038 | if (page != pagecache_page) | |
0f792cf9 NH |
4039 | if (!trylock_page(page)) { |
4040 | need_wait_lock = 1; | |
4041 | goto out_ptl; | |
4042 | } | |
b4d1d99f | 4043 | |
0f792cf9 | 4044 | get_page(page); |
b4d1d99f | 4045 | |
788c7df4 | 4046 | if (flags & FAULT_FLAG_WRITE) { |
106c992a | 4047 | if (!huge_pte_write(entry)) { |
974e6d66 | 4048 | ret = hugetlb_cow(mm, vma, address, ptep, |
3999f52e | 4049 | pagecache_page, ptl); |
0f792cf9 | 4050 | goto out_put_page; |
b4d1d99f | 4051 | } |
106c992a | 4052 | entry = huge_pte_mkdirty(entry); |
b4d1d99f DG |
4053 | } |
4054 | entry = pte_mkyoung(entry); | |
285b8dca | 4055 | if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, |
788c7df4 | 4056 | flags & FAULT_FLAG_WRITE)) |
285b8dca | 4057 | update_mmu_cache(vma, haddr, ptep); |
0f792cf9 NH |
4058 | out_put_page: |
4059 | if (page != pagecache_page) | |
4060 | unlock_page(page); | |
4061 | put_page(page); | |
cb900f41 KS |
4062 | out_ptl: |
4063 | spin_unlock(ptl); | |
57303d80 AW |
4064 | |
4065 | if (pagecache_page) { | |
4066 | unlock_page(pagecache_page); | |
4067 | put_page(pagecache_page); | |
4068 | } | |
b4d1d99f | 4069 | out_mutex: |
c672c7f2 | 4070 | mutex_unlock(&hugetlb_fault_mutex_table[hash]); |
0f792cf9 NH |
4071 | /* |
4072 | * Generally it's safe to hold refcount during waiting page lock. But | |
4073 | * here we just wait to defer the next page fault to avoid busy loop and | |
4074 | * the page is not used after unlocked before returning from the current | |
4075 | * page fault. So we are safe from accessing freed page, even if we wait | |
4076 | * here without taking refcount. | |
4077 | */ | |
4078 | if (need_wait_lock) | |
4079 | wait_on_page_locked(page); | |
1e8f889b | 4080 | return ret; |
86e5216f AL |
4081 | } |
4082 | ||
8fb5debc MK |
4083 | /* |
4084 | * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with | |
4085 | * modifications for huge pages. | |
4086 | */ | |
4087 | int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, | |
4088 | pte_t *dst_pte, | |
4089 | struct vm_area_struct *dst_vma, | |
4090 | unsigned long dst_addr, | |
4091 | unsigned long src_addr, | |
4092 | struct page **pagep) | |
4093 | { | |
1e392147 AA |
4094 | struct address_space *mapping; |
4095 | pgoff_t idx; | |
4096 | unsigned long size; | |
1c9e8def | 4097 | int vm_shared = dst_vma->vm_flags & VM_SHARED; |
8fb5debc MK |
4098 | struct hstate *h = hstate_vma(dst_vma); |
4099 | pte_t _dst_pte; | |
4100 | spinlock_t *ptl; | |
4101 | int ret; | |
4102 | struct page *page; | |
4103 | ||
4104 | if (!*pagep) { | |
4105 | ret = -ENOMEM; | |
4106 | page = alloc_huge_page(dst_vma, dst_addr, 0); | |
4107 | if (IS_ERR(page)) | |
4108 | goto out; | |
4109 | ||
4110 | ret = copy_huge_page_from_user(page, | |
4111 | (const void __user *) src_addr, | |
810a56b9 | 4112 | pages_per_huge_page(h), false); |
8fb5debc MK |
4113 | |
4114 | /* fallback to copy_from_user outside mmap_sem */ | |
4115 | if (unlikely(ret)) { | |
9e368259 | 4116 | ret = -ENOENT; |
8fb5debc MK |
4117 | *pagep = page; |
4118 | /* don't free the page */ | |
4119 | goto out; | |
4120 | } | |
4121 | } else { | |
4122 | page = *pagep; | |
4123 | *pagep = NULL; | |
4124 | } | |
4125 | ||
4126 | /* | |
4127 | * The memory barrier inside __SetPageUptodate makes sure that | |
4128 | * preceding stores to the page contents become visible before | |
4129 | * the set_pte_at() write. | |
4130 | */ | |
4131 | __SetPageUptodate(page); | |
8fb5debc | 4132 | |
1e392147 AA |
4133 | mapping = dst_vma->vm_file->f_mapping; |
4134 | idx = vma_hugecache_offset(h, dst_vma, dst_addr); | |
4135 | ||
1c9e8def MK |
4136 | /* |
4137 | * If shared, add to page cache | |
4138 | */ | |
4139 | if (vm_shared) { | |
1e392147 AA |
4140 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4141 | ret = -EFAULT; | |
4142 | if (idx >= size) | |
4143 | goto out_release_nounlock; | |
1c9e8def | 4144 | |
1e392147 AA |
4145 | /* |
4146 | * Serialization between remove_inode_hugepages() and | |
4147 | * huge_add_to_page_cache() below happens through the | |
4148 | * hugetlb_fault_mutex_table that here must be hold by | |
4149 | * the caller. | |
4150 | */ | |
1c9e8def MK |
4151 | ret = huge_add_to_page_cache(page, mapping, idx); |
4152 | if (ret) | |
4153 | goto out_release_nounlock; | |
4154 | } | |
4155 | ||
8fb5debc MK |
4156 | ptl = huge_pte_lockptr(h, dst_mm, dst_pte); |
4157 | spin_lock(ptl); | |
4158 | ||
1e392147 AA |
4159 | /* |
4160 | * Recheck the i_size after holding PT lock to make sure not | |
4161 | * to leave any page mapped (as page_mapped()) beyond the end | |
4162 | * of the i_size (remove_inode_hugepages() is strict about | |
4163 | * enforcing that). If we bail out here, we'll also leave a | |
4164 | * page in the radix tree in the vm_shared case beyond the end | |
4165 | * of the i_size, but remove_inode_hugepages() will take care | |
4166 | * of it as soon as we drop the hugetlb_fault_mutex_table. | |
4167 | */ | |
4168 | size = i_size_read(mapping->host) >> huge_page_shift(h); | |
4169 | ret = -EFAULT; | |
4170 | if (idx >= size) | |
4171 | goto out_release_unlock; | |
4172 | ||
8fb5debc MK |
4173 | ret = -EEXIST; |
4174 | if (!huge_pte_none(huge_ptep_get(dst_pte))) | |
4175 | goto out_release_unlock; | |
4176 | ||
1c9e8def MK |
4177 | if (vm_shared) { |
4178 | page_dup_rmap(page, true); | |
4179 | } else { | |
4180 | ClearPagePrivate(page); | |
4181 | hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); | |
4182 | } | |
8fb5debc MK |
4183 | |
4184 | _dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE); | |
4185 | if (dst_vma->vm_flags & VM_WRITE) | |
4186 | _dst_pte = huge_pte_mkdirty(_dst_pte); | |
4187 | _dst_pte = pte_mkyoung(_dst_pte); | |
4188 | ||
4189 | set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); | |
4190 | ||
4191 | (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, | |
4192 | dst_vma->vm_flags & VM_WRITE); | |
4193 | hugetlb_count_add(pages_per_huge_page(h), dst_mm); | |
4194 | ||
4195 | /* No need to invalidate - it was non-present before */ | |
4196 | update_mmu_cache(dst_vma, dst_addr, dst_pte); | |
4197 | ||
4198 | spin_unlock(ptl); | |
cb6acd01 | 4199 | set_page_huge_active(page); |
1c9e8def MK |
4200 | if (vm_shared) |
4201 | unlock_page(page); | |
8fb5debc MK |
4202 | ret = 0; |
4203 | out: | |
4204 | return ret; | |
4205 | out_release_unlock: | |
4206 | spin_unlock(ptl); | |
1c9e8def MK |
4207 | if (vm_shared) |
4208 | unlock_page(page); | |
5af10dfd | 4209 | out_release_nounlock: |
8fb5debc MK |
4210 | put_page(page); |
4211 | goto out; | |
4212 | } | |
4213 | ||
28a35716 ML |
4214 | long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
4215 | struct page **pages, struct vm_area_struct **vmas, | |
4216 | unsigned long *position, unsigned long *nr_pages, | |
87ffc118 | 4217 | long i, unsigned int flags, int *nonblocking) |
63551ae0 | 4218 | { |
d5d4b0aa KC |
4219 | unsigned long pfn_offset; |
4220 | unsigned long vaddr = *position; | |
28a35716 | 4221 | unsigned long remainder = *nr_pages; |
a5516438 | 4222 | struct hstate *h = hstate_vma(vma); |
2be7cfed | 4223 | int err = -EFAULT; |
63551ae0 | 4224 | |
63551ae0 | 4225 | while (vaddr < vma->vm_end && remainder) { |
4c887265 | 4226 | pte_t *pte; |
cb900f41 | 4227 | spinlock_t *ptl = NULL; |
2a15efc9 | 4228 | int absent; |
4c887265 | 4229 | struct page *page; |
63551ae0 | 4230 | |
02057967 DR |
4231 | /* |
4232 | * If we have a pending SIGKILL, don't keep faulting pages and | |
4233 | * potentially allocating memory. | |
4234 | */ | |
fa45f116 | 4235 | if (fatal_signal_pending(current)) { |
02057967 DR |
4236 | remainder = 0; |
4237 | break; | |
4238 | } | |
4239 | ||
4c887265 AL |
4240 | /* |
4241 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2a15efc9 | 4242 | * each hugepage. We have to make sure we get the |
4c887265 | 4243 | * first, for the page indexing below to work. |
cb900f41 KS |
4244 | * |
4245 | * Note that page table lock is not held when pte is null. | |
4c887265 | 4246 | */ |
7868a208 PA |
4247 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), |
4248 | huge_page_size(h)); | |
cb900f41 KS |
4249 | if (pte) |
4250 | ptl = huge_pte_lock(h, mm, pte); | |
2a15efc9 HD |
4251 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
4252 | ||
4253 | /* | |
4254 | * When coredumping, it suits get_dump_page if we just return | |
3ae77f43 HD |
4255 | * an error where there's an empty slot with no huge pagecache |
4256 | * to back it. This way, we avoid allocating a hugepage, and | |
4257 | * the sparse dumpfile avoids allocating disk blocks, but its | |
4258 | * huge holes still show up with zeroes where they need to be. | |
2a15efc9 | 4259 | */ |
3ae77f43 HD |
4260 | if (absent && (flags & FOLL_DUMP) && |
4261 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { | |
cb900f41 KS |
4262 | if (pte) |
4263 | spin_unlock(ptl); | |
2a15efc9 HD |
4264 | remainder = 0; |
4265 | break; | |
4266 | } | |
63551ae0 | 4267 | |
9cc3a5bd NH |
4268 | /* |
4269 | * We need call hugetlb_fault for both hugepages under migration | |
4270 | * (in which case hugetlb_fault waits for the migration,) and | |
4271 | * hwpoisoned hugepages (in which case we need to prevent the | |
4272 | * caller from accessing to them.) In order to do this, we use | |
4273 | * here is_swap_pte instead of is_hugetlb_entry_migration and | |
4274 | * is_hugetlb_entry_hwpoisoned. This is because it simply covers | |
4275 | * both cases, and because we can't follow correct pages | |
4276 | * directly from any kind of swap entries. | |
4277 | */ | |
4278 | if (absent || is_swap_pte(huge_ptep_get(pte)) || | |
106c992a GS |
4279 | ((flags & FOLL_WRITE) && |
4280 | !huge_pte_write(huge_ptep_get(pte)))) { | |
2b740303 | 4281 | vm_fault_t ret; |
87ffc118 | 4282 | unsigned int fault_flags = 0; |
63551ae0 | 4283 | |
cb900f41 KS |
4284 | if (pte) |
4285 | spin_unlock(ptl); | |
87ffc118 AA |
4286 | if (flags & FOLL_WRITE) |
4287 | fault_flags |= FAULT_FLAG_WRITE; | |
4288 | if (nonblocking) | |
4289 | fault_flags |= FAULT_FLAG_ALLOW_RETRY; | |
4290 | if (flags & FOLL_NOWAIT) | |
4291 | fault_flags |= FAULT_FLAG_ALLOW_RETRY | | |
4292 | FAULT_FLAG_RETRY_NOWAIT; | |
4293 | if (flags & FOLL_TRIED) { | |
4294 | VM_WARN_ON_ONCE(fault_flags & | |
4295 | FAULT_FLAG_ALLOW_RETRY); | |
4296 | fault_flags |= FAULT_FLAG_TRIED; | |
4297 | } | |
4298 | ret = hugetlb_fault(mm, vma, vaddr, fault_flags); | |
4299 | if (ret & VM_FAULT_ERROR) { | |
2be7cfed | 4300 | err = vm_fault_to_errno(ret, flags); |
87ffc118 AA |
4301 | remainder = 0; |
4302 | break; | |
4303 | } | |
4304 | if (ret & VM_FAULT_RETRY) { | |
1ac25013 AA |
4305 | if (nonblocking && |
4306 | !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) | |
87ffc118 AA |
4307 | *nonblocking = 0; |
4308 | *nr_pages = 0; | |
4309 | /* | |
4310 | * VM_FAULT_RETRY must not return an | |
4311 | * error, it will return zero | |
4312 | * instead. | |
4313 | * | |
4314 | * No need to update "position" as the | |
4315 | * caller will not check it after | |
4316 | * *nr_pages is set to 0. | |
4317 | */ | |
4318 | return i; | |
4319 | } | |
4320 | continue; | |
4c887265 AL |
4321 | } |
4322 | ||
a5516438 | 4323 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 4324 | page = pte_page(huge_ptep_get(pte)); |
8fde12ca LT |
4325 | |
4326 | /* | |
4327 | * Instead of doing 'try_get_page()' below in the same_page | |
4328 | * loop, just check the count once here. | |
4329 | */ | |
4330 | if (unlikely(page_count(page) <= 0)) { | |
4331 | if (pages) { | |
4332 | spin_unlock(ptl); | |
4333 | remainder = 0; | |
4334 | err = -ENOMEM; | |
4335 | break; | |
4336 | } | |
4337 | } | |
d5d4b0aa | 4338 | same_page: |
d6692183 | 4339 | if (pages) { |
2a15efc9 | 4340 | pages[i] = mem_map_offset(page, pfn_offset); |
ddc58f27 | 4341 | get_page(pages[i]); |
d6692183 | 4342 | } |
63551ae0 DG |
4343 | |
4344 | if (vmas) | |
4345 | vmas[i] = vma; | |
4346 | ||
4347 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 4348 | ++pfn_offset; |
63551ae0 DG |
4349 | --remainder; |
4350 | ++i; | |
d5d4b0aa | 4351 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 4352 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa KC |
4353 | /* |
4354 | * We use pfn_offset to avoid touching the pageframes | |
4355 | * of this compound page. | |
4356 | */ | |
4357 | goto same_page; | |
4358 | } | |
cb900f41 | 4359 | spin_unlock(ptl); |
63551ae0 | 4360 | } |
28a35716 | 4361 | *nr_pages = remainder; |
87ffc118 AA |
4362 | /* |
4363 | * setting position is actually required only if remainder is | |
4364 | * not zero but it's faster not to add a "if (remainder)" | |
4365 | * branch. | |
4366 | */ | |
63551ae0 DG |
4367 | *position = vaddr; |
4368 | ||
2be7cfed | 4369 | return i ? i : err; |
63551ae0 | 4370 | } |
8f860591 | 4371 | |
5491ae7b AK |
4372 | #ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE |
4373 | /* | |
4374 | * ARCHes with special requirements for evicting HUGETLB backing TLB entries can | |
4375 | * implement this. | |
4376 | */ | |
4377 | #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) | |
4378 | #endif | |
4379 | ||
7da4d641 | 4380 | unsigned long hugetlb_change_protection(struct vm_area_struct *vma, |
8f860591 ZY |
4381 | unsigned long address, unsigned long end, pgprot_t newprot) |
4382 | { | |
4383 | struct mm_struct *mm = vma->vm_mm; | |
4384 | unsigned long start = address; | |
4385 | pte_t *ptep; | |
4386 | pte_t pte; | |
a5516438 | 4387 | struct hstate *h = hstate_vma(vma); |
7da4d641 | 4388 | unsigned long pages = 0; |
dff11abe | 4389 | bool shared_pmd = false; |
ac46d4f3 | 4390 | struct mmu_notifier_range range; |
dff11abe MK |
4391 | |
4392 | /* | |
4393 | * In the case of shared PMDs, the area to flush could be beyond | |
ac46d4f3 | 4394 | * start/end. Set range.start/range.end to cover the maximum possible |
dff11abe MK |
4395 | * range if PMD sharing is possible. |
4396 | */ | |
ac46d4f3 JG |
4397 | mmu_notifier_range_init(&range, mm, start, end); |
4398 | adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); | |
8f860591 ZY |
4399 | |
4400 | BUG_ON(address >= end); | |
ac46d4f3 | 4401 | flush_cache_range(vma, range.start, range.end); |
8f860591 | 4402 | |
ac46d4f3 | 4403 | mmu_notifier_invalidate_range_start(&range); |
83cde9e8 | 4404 | i_mmap_lock_write(vma->vm_file->f_mapping); |
a5516438 | 4405 | for (; address < end; address += huge_page_size(h)) { |
cb900f41 | 4406 | spinlock_t *ptl; |
7868a208 | 4407 | ptep = huge_pte_offset(mm, address, huge_page_size(h)); |
8f860591 ZY |
4408 | if (!ptep) |
4409 | continue; | |
cb900f41 | 4410 | ptl = huge_pte_lock(h, mm, ptep); |
7da4d641 PZ |
4411 | if (huge_pmd_unshare(mm, &address, ptep)) { |
4412 | pages++; | |
cb900f41 | 4413 | spin_unlock(ptl); |
dff11abe | 4414 | shared_pmd = true; |
39dde65c | 4415 | continue; |
7da4d641 | 4416 | } |
a8bda28d NH |
4417 | pte = huge_ptep_get(ptep); |
4418 | if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { | |
4419 | spin_unlock(ptl); | |
4420 | continue; | |
4421 | } | |
4422 | if (unlikely(is_hugetlb_entry_migration(pte))) { | |
4423 | swp_entry_t entry = pte_to_swp_entry(pte); | |
4424 | ||
4425 | if (is_write_migration_entry(entry)) { | |
4426 | pte_t newpte; | |
4427 | ||
4428 | make_migration_entry_read(&entry); | |
4429 | newpte = swp_entry_to_pte(entry); | |
e5251fd4 PA |
4430 | set_huge_swap_pte_at(mm, address, ptep, |
4431 | newpte, huge_page_size(h)); | |
a8bda28d NH |
4432 | pages++; |
4433 | } | |
4434 | spin_unlock(ptl); | |
4435 | continue; | |
4436 | } | |
4437 | if (!huge_pte_none(pte)) { | |
023bdd00 AK |
4438 | pte_t old_pte; |
4439 | ||
4440 | old_pte = huge_ptep_modify_prot_start(vma, address, ptep); | |
4441 | pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); | |
be7517d6 | 4442 | pte = arch_make_huge_pte(pte, vma, NULL, 0); |
023bdd00 | 4443 | huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); |
7da4d641 | 4444 | pages++; |
8f860591 | 4445 | } |
cb900f41 | 4446 | spin_unlock(ptl); |
8f860591 | 4447 | } |
d833352a | 4448 | /* |
c8c06efa | 4449 | * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare |
d833352a | 4450 | * may have cleared our pud entry and done put_page on the page table: |
c8c06efa | 4451 | * once we release i_mmap_rwsem, another task can do the final put_page |
dff11abe MK |
4452 | * and that page table be reused and filled with junk. If we actually |
4453 | * did unshare a page of pmds, flush the range corresponding to the pud. | |
d833352a | 4454 | */ |
dff11abe | 4455 | if (shared_pmd) |
ac46d4f3 | 4456 | flush_hugetlb_tlb_range(vma, range.start, range.end); |
dff11abe MK |
4457 | else |
4458 | flush_hugetlb_tlb_range(vma, start, end); | |
0f10851e JG |
4459 | /* |
4460 | * No need to call mmu_notifier_invalidate_range() we are downgrading | |
4461 | * page table protection not changing it to point to a new page. | |
4462 | * | |
ad56b738 | 4463 | * See Documentation/vm/mmu_notifier.rst |
0f10851e | 4464 | */ |
83cde9e8 | 4465 | i_mmap_unlock_write(vma->vm_file->f_mapping); |
ac46d4f3 | 4466 | mmu_notifier_invalidate_range_end(&range); |
7da4d641 PZ |
4467 | |
4468 | return pages << h->order; | |
8f860591 ZY |
4469 | } |
4470 | ||
a1e78772 MG |
4471 | int hugetlb_reserve_pages(struct inode *inode, |
4472 | long from, long to, | |
5a6fe125 | 4473 | struct vm_area_struct *vma, |
ca16d140 | 4474 | vm_flags_t vm_flags) |
e4e574b7 | 4475 | { |
17c9d12e | 4476 | long ret, chg; |
a5516438 | 4477 | struct hstate *h = hstate_inode(inode); |
90481622 | 4478 | struct hugepage_subpool *spool = subpool_inode(inode); |
9119a41e | 4479 | struct resv_map *resv_map; |
1c5ecae3 | 4480 | long gbl_reserve; |
e4e574b7 | 4481 | |
63489f8e MK |
4482 | /* This should never happen */ |
4483 | if (from > to) { | |
4484 | VM_WARN(1, "%s called with a negative range\n", __func__); | |
4485 | return -EINVAL; | |
4486 | } | |
4487 | ||
17c9d12e MG |
4488 | /* |
4489 | * Only apply hugepage reservation if asked. At fault time, an | |
4490 | * attempt will be made for VM_NORESERVE to allocate a page | |
90481622 | 4491 | * without using reserves |
17c9d12e | 4492 | */ |
ca16d140 | 4493 | if (vm_flags & VM_NORESERVE) |
17c9d12e MG |
4494 | return 0; |
4495 | ||
a1e78772 MG |
4496 | /* |
4497 | * Shared mappings base their reservation on the number of pages that | |
4498 | * are already allocated on behalf of the file. Private mappings need | |
4499 | * to reserve the full area even if read-only as mprotect() may be | |
4500 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
4501 | */ | |
9119a41e | 4502 | if (!vma || vma->vm_flags & VM_MAYSHARE) { |
4e35f483 | 4503 | resv_map = inode_resv_map(inode); |
9119a41e | 4504 | |
1406ec9b | 4505 | chg = region_chg(resv_map, from, to); |
9119a41e JK |
4506 | |
4507 | } else { | |
4508 | resv_map = resv_map_alloc(); | |
17c9d12e MG |
4509 | if (!resv_map) |
4510 | return -ENOMEM; | |
4511 | ||
a1e78772 | 4512 | chg = to - from; |
84afd99b | 4513 | |
17c9d12e MG |
4514 | set_vma_resv_map(vma, resv_map); |
4515 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
4516 | } | |
4517 | ||
c50ac050 DH |
4518 | if (chg < 0) { |
4519 | ret = chg; | |
4520 | goto out_err; | |
4521 | } | |
8a630112 | 4522 | |
1c5ecae3 MK |
4523 | /* |
4524 | * There must be enough pages in the subpool for the mapping. If | |
4525 | * the subpool has a minimum size, there may be some global | |
4526 | * reservations already in place (gbl_reserve). | |
4527 | */ | |
4528 | gbl_reserve = hugepage_subpool_get_pages(spool, chg); | |
4529 | if (gbl_reserve < 0) { | |
c50ac050 DH |
4530 | ret = -ENOSPC; |
4531 | goto out_err; | |
4532 | } | |
5a6fe125 MG |
4533 | |
4534 | /* | |
17c9d12e | 4535 | * Check enough hugepages are available for the reservation. |
90481622 | 4536 | * Hand the pages back to the subpool if there are not |
5a6fe125 | 4537 | */ |
1c5ecae3 | 4538 | ret = hugetlb_acct_memory(h, gbl_reserve); |
68842c9b | 4539 | if (ret < 0) { |
1c5ecae3 MK |
4540 | /* put back original number of pages, chg */ |
4541 | (void)hugepage_subpool_put_pages(spool, chg); | |
c50ac050 | 4542 | goto out_err; |
68842c9b | 4543 | } |
17c9d12e MG |
4544 | |
4545 | /* | |
4546 | * Account for the reservations made. Shared mappings record regions | |
4547 | * that have reservations as they are shared by multiple VMAs. | |
4548 | * When the last VMA disappears, the region map says how much | |
4549 | * the reservation was and the page cache tells how much of | |
4550 | * the reservation was consumed. Private mappings are per-VMA and | |
4551 | * only the consumed reservations are tracked. When the VMA | |
4552 | * disappears, the original reservation is the VMA size and the | |
4553 | * consumed reservations are stored in the map. Hence, nothing | |
4554 | * else has to be done for private mappings here | |
4555 | */ | |
33039678 MK |
4556 | if (!vma || vma->vm_flags & VM_MAYSHARE) { |
4557 | long add = region_add(resv_map, from, to); | |
4558 | ||
4559 | if (unlikely(chg > add)) { | |
4560 | /* | |
4561 | * pages in this range were added to the reserve | |
4562 | * map between region_chg and region_add. This | |
4563 | * indicates a race with alloc_huge_page. Adjust | |
4564 | * the subpool and reserve counts modified above | |
4565 | * based on the difference. | |
4566 | */ | |
4567 | long rsv_adjust; | |
4568 | ||
4569 | rsv_adjust = hugepage_subpool_put_pages(spool, | |
4570 | chg - add); | |
4571 | hugetlb_acct_memory(h, -rsv_adjust); | |
4572 | } | |
4573 | } | |
a43a8c39 | 4574 | return 0; |
c50ac050 | 4575 | out_err: |
5e911373 | 4576 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
ff8c0c53 MK |
4577 | /* Don't call region_abort if region_chg failed */ |
4578 | if (chg >= 0) | |
4579 | region_abort(resv_map, from, to); | |
f031dd27 JK |
4580 | if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
4581 | kref_put(&resv_map->refs, resv_map_release); | |
c50ac050 | 4582 | return ret; |
a43a8c39 KC |
4583 | } |
4584 | ||
b5cec28d MK |
4585 | long hugetlb_unreserve_pages(struct inode *inode, long start, long end, |
4586 | long freed) | |
a43a8c39 | 4587 | { |
a5516438 | 4588 | struct hstate *h = hstate_inode(inode); |
4e35f483 | 4589 | struct resv_map *resv_map = inode_resv_map(inode); |
9119a41e | 4590 | long chg = 0; |
90481622 | 4591 | struct hugepage_subpool *spool = subpool_inode(inode); |
1c5ecae3 | 4592 | long gbl_reserve; |
45c682a6 | 4593 | |
b5cec28d MK |
4594 | if (resv_map) { |
4595 | chg = region_del(resv_map, start, end); | |
4596 | /* | |
4597 | * region_del() can fail in the rare case where a region | |
4598 | * must be split and another region descriptor can not be | |
4599 | * allocated. If end == LONG_MAX, it will not fail. | |
4600 | */ | |
4601 | if (chg < 0) | |
4602 | return chg; | |
4603 | } | |
4604 | ||
45c682a6 | 4605 | spin_lock(&inode->i_lock); |
e4c6f8be | 4606 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
4607 | spin_unlock(&inode->i_lock); |
4608 | ||
1c5ecae3 MK |
4609 | /* |
4610 | * If the subpool has a minimum size, the number of global | |
4611 | * reservations to be released may be adjusted. | |
4612 | */ | |
4613 | gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); | |
4614 | hugetlb_acct_memory(h, -gbl_reserve); | |
b5cec28d MK |
4615 | |
4616 | return 0; | |
a43a8c39 | 4617 | } |
93f70f90 | 4618 | |
3212b535 SC |
4619 | #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE |
4620 | static unsigned long page_table_shareable(struct vm_area_struct *svma, | |
4621 | struct vm_area_struct *vma, | |
4622 | unsigned long addr, pgoff_t idx) | |
4623 | { | |
4624 | unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + | |
4625 | svma->vm_start; | |
4626 | unsigned long sbase = saddr & PUD_MASK; | |
4627 | unsigned long s_end = sbase + PUD_SIZE; | |
4628 | ||
4629 | /* Allow segments to share if only one is marked locked */ | |
de60f5f1 EM |
4630 | unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; |
4631 | unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; | |
3212b535 SC |
4632 | |
4633 | /* | |
4634 | * match the virtual addresses, permission and the alignment of the | |
4635 | * page table page. | |
4636 | */ | |
4637 | if (pmd_index(addr) != pmd_index(saddr) || | |
4638 | vm_flags != svm_flags || | |
4639 | sbase < svma->vm_start || svma->vm_end < s_end) | |
4640 | return 0; | |
4641 | ||
4642 | return saddr; | |
4643 | } | |
4644 | ||
31aafb45 | 4645 | static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) |
3212b535 SC |
4646 | { |
4647 | unsigned long base = addr & PUD_MASK; | |
4648 | unsigned long end = base + PUD_SIZE; | |
4649 | ||
4650 | /* | |
4651 | * check on proper vm_flags and page table alignment | |
4652 | */ | |
017b1660 | 4653 | if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) |
31aafb45 NK |
4654 | return true; |
4655 | return false; | |
3212b535 SC |
4656 | } |
4657 | ||
017b1660 MK |
4658 | /* |
4659 | * Determine if start,end range within vma could be mapped by shared pmd. | |
4660 | * If yes, adjust start and end to cover range associated with possible | |
4661 | * shared pmd mappings. | |
4662 | */ | |
4663 | void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, | |
4664 | unsigned long *start, unsigned long *end) | |
4665 | { | |
4666 | unsigned long check_addr = *start; | |
4667 | ||
4668 | if (!(vma->vm_flags & VM_MAYSHARE)) | |
4669 | return; | |
4670 | ||
4671 | for (check_addr = *start; check_addr < *end; check_addr += PUD_SIZE) { | |
4672 | unsigned long a_start = check_addr & PUD_MASK; | |
4673 | unsigned long a_end = a_start + PUD_SIZE; | |
4674 | ||
4675 | /* | |
4676 | * If sharing is possible, adjust start/end if necessary. | |
4677 | */ | |
4678 | if (range_in_vma(vma, a_start, a_end)) { | |
4679 | if (a_start < *start) | |
4680 | *start = a_start; | |
4681 | if (a_end > *end) | |
4682 | *end = a_end; | |
4683 | } | |
4684 | } | |
4685 | } | |
4686 | ||
3212b535 SC |
4687 | /* |
4688 | * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() | |
4689 | * and returns the corresponding pte. While this is not necessary for the | |
4690 | * !shared pmd case because we can allocate the pmd later as well, it makes the | |
ddeaab32 MK |
4691 | * code much cleaner. pmd allocation is essential for the shared case because |
4692 | * pud has to be populated inside the same i_mmap_rwsem section - otherwise | |
4693 | * racing tasks could either miss the sharing (see huge_pte_offset) or select a | |
4694 | * bad pmd for sharing. | |
3212b535 SC |
4695 | */ |
4696 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
4697 | { | |
4698 | struct vm_area_struct *vma = find_vma(mm, addr); | |
4699 | struct address_space *mapping = vma->vm_file->f_mapping; | |
4700 | pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + | |
4701 | vma->vm_pgoff; | |
4702 | struct vm_area_struct *svma; | |
4703 | unsigned long saddr; | |
4704 | pte_t *spte = NULL; | |
4705 | pte_t *pte; | |
cb900f41 | 4706 | spinlock_t *ptl; |
3212b535 SC |
4707 | |
4708 | if (!vma_shareable(vma, addr)) | |
4709 | return (pte_t *)pmd_alloc(mm, pud, addr); | |
4710 | ||
ddeaab32 | 4711 | i_mmap_lock_write(mapping); |
3212b535 SC |
4712 | vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { |
4713 | if (svma == vma) | |
4714 | continue; | |
4715 | ||
4716 | saddr = page_table_shareable(svma, vma, addr, idx); | |
4717 | if (saddr) { | |
7868a208 PA |
4718 | spte = huge_pte_offset(svma->vm_mm, saddr, |
4719 | vma_mmu_pagesize(svma)); | |
3212b535 SC |
4720 | if (spte) { |
4721 | get_page(virt_to_page(spte)); | |
4722 | break; | |
4723 | } | |
4724 | } | |
4725 | } | |
4726 | ||
4727 | if (!spte) | |
4728 | goto out; | |
4729 | ||
8bea8052 | 4730 | ptl = huge_pte_lock(hstate_vma(vma), mm, spte); |
dc6c9a35 | 4731 | if (pud_none(*pud)) { |
3212b535 SC |
4732 | pud_populate(mm, pud, |
4733 | (pmd_t *)((unsigned long)spte & PAGE_MASK)); | |
c17b1f42 | 4734 | mm_inc_nr_pmds(mm); |
dc6c9a35 | 4735 | } else { |
3212b535 | 4736 | put_page(virt_to_page(spte)); |
dc6c9a35 | 4737 | } |
cb900f41 | 4738 | spin_unlock(ptl); |
3212b535 SC |
4739 | out: |
4740 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
ddeaab32 | 4741 | i_mmap_unlock_write(mapping); |
3212b535 SC |
4742 | return pte; |
4743 | } | |
4744 | ||
4745 | /* | |
4746 | * unmap huge page backed by shared pte. | |
4747 | * | |
4748 | * Hugetlb pte page is ref counted at the time of mapping. If pte is shared | |
4749 | * indicated by page_count > 1, unmap is achieved by clearing pud and | |
4750 | * decrementing the ref count. If count == 1, the pte page is not shared. | |
4751 | * | |
ddeaab32 | 4752 | * called with page table lock held. |
3212b535 SC |
4753 | * |
4754 | * returns: 1 successfully unmapped a shared pte page | |
4755 | * 0 the underlying pte page is not shared, or it is the last user | |
4756 | */ | |
4757 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
4758 | { | |
4759 | pgd_t *pgd = pgd_offset(mm, *addr); | |
c2febafc KS |
4760 | p4d_t *p4d = p4d_offset(pgd, *addr); |
4761 | pud_t *pud = pud_offset(p4d, *addr); | |
3212b535 SC |
4762 | |
4763 | BUG_ON(page_count(virt_to_page(ptep)) == 0); | |
4764 | if (page_count(virt_to_page(ptep)) == 1) | |
4765 | return 0; | |
4766 | ||
4767 | pud_clear(pud); | |
4768 | put_page(virt_to_page(ptep)); | |
dc6c9a35 | 4769 | mm_dec_nr_pmds(mm); |
3212b535 SC |
4770 | *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; |
4771 | return 1; | |
4772 | } | |
9e5fc74c SC |
4773 | #define want_pmd_share() (1) |
4774 | #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ | |
4775 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
4776 | { | |
4777 | return NULL; | |
4778 | } | |
e81f2d22 ZZ |
4779 | |
4780 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
4781 | { | |
4782 | return 0; | |
4783 | } | |
017b1660 MK |
4784 | |
4785 | void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, | |
4786 | unsigned long *start, unsigned long *end) | |
4787 | { | |
4788 | } | |
9e5fc74c | 4789 | #define want_pmd_share() (0) |
3212b535 SC |
4790 | #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ |
4791 | ||
9e5fc74c SC |
4792 | #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB |
4793 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
4794 | unsigned long addr, unsigned long sz) | |
4795 | { | |
4796 | pgd_t *pgd; | |
c2febafc | 4797 | p4d_t *p4d; |
9e5fc74c SC |
4798 | pud_t *pud; |
4799 | pte_t *pte = NULL; | |
4800 | ||
4801 | pgd = pgd_offset(mm, addr); | |
f4f0a3d8 KS |
4802 | p4d = p4d_alloc(mm, pgd, addr); |
4803 | if (!p4d) | |
4804 | return NULL; | |
c2febafc | 4805 | pud = pud_alloc(mm, p4d, addr); |
9e5fc74c SC |
4806 | if (pud) { |
4807 | if (sz == PUD_SIZE) { | |
4808 | pte = (pte_t *)pud; | |
4809 | } else { | |
4810 | BUG_ON(sz != PMD_SIZE); | |
4811 | if (want_pmd_share() && pud_none(*pud)) | |
4812 | pte = huge_pmd_share(mm, addr, pud); | |
4813 | else | |
4814 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
4815 | } | |
4816 | } | |
4e666314 | 4817 | BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); |
9e5fc74c SC |
4818 | |
4819 | return pte; | |
4820 | } | |
4821 | ||
9b19df29 PA |
4822 | /* |
4823 | * huge_pte_offset() - Walk the page table to resolve the hugepage | |
4824 | * entry at address @addr | |
4825 | * | |
4826 | * Return: Pointer to page table or swap entry (PUD or PMD) for | |
4827 | * address @addr, or NULL if a p*d_none() entry is encountered and the | |
4828 | * size @sz doesn't match the hugepage size at this level of the page | |
4829 | * table. | |
4830 | */ | |
7868a208 PA |
4831 | pte_t *huge_pte_offset(struct mm_struct *mm, |
4832 | unsigned long addr, unsigned long sz) | |
9e5fc74c SC |
4833 | { |
4834 | pgd_t *pgd; | |
c2febafc | 4835 | p4d_t *p4d; |
9e5fc74c | 4836 | pud_t *pud; |
c2febafc | 4837 | pmd_t *pmd; |
9e5fc74c SC |
4838 | |
4839 | pgd = pgd_offset(mm, addr); | |
c2febafc KS |
4840 | if (!pgd_present(*pgd)) |
4841 | return NULL; | |
4842 | p4d = p4d_offset(pgd, addr); | |
4843 | if (!p4d_present(*p4d)) | |
4844 | return NULL; | |
9b19df29 | 4845 | |
c2febafc | 4846 | pud = pud_offset(p4d, addr); |
9b19df29 | 4847 | if (sz != PUD_SIZE && pud_none(*pud)) |
c2febafc | 4848 | return NULL; |
9b19df29 PA |
4849 | /* hugepage or swap? */ |
4850 | if (pud_huge(*pud) || !pud_present(*pud)) | |
c2febafc | 4851 | return (pte_t *)pud; |
9b19df29 | 4852 | |
c2febafc | 4853 | pmd = pmd_offset(pud, addr); |
9b19df29 PA |
4854 | if (sz != PMD_SIZE && pmd_none(*pmd)) |
4855 | return NULL; | |
4856 | /* hugepage or swap? */ | |
4857 | if (pmd_huge(*pmd) || !pmd_present(*pmd)) | |
4858 | return (pte_t *)pmd; | |
4859 | ||
4860 | return NULL; | |
9e5fc74c SC |
4861 | } |
4862 | ||
61f77eda NH |
4863 | #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ |
4864 | ||
4865 | /* | |
4866 | * These functions are overwritable if your architecture needs its own | |
4867 | * behavior. | |
4868 | */ | |
4869 | struct page * __weak | |
4870 | follow_huge_addr(struct mm_struct *mm, unsigned long address, | |
4871 | int write) | |
4872 | { | |
4873 | return ERR_PTR(-EINVAL); | |
4874 | } | |
4875 | ||
4dc71451 AK |
4876 | struct page * __weak |
4877 | follow_huge_pd(struct vm_area_struct *vma, | |
4878 | unsigned long address, hugepd_t hpd, int flags, int pdshift) | |
4879 | { | |
4880 | WARN(1, "hugepd follow called with no support for hugepage directory format\n"); | |
4881 | return NULL; | |
4882 | } | |
4883 | ||
61f77eda | 4884 | struct page * __weak |
9e5fc74c | 4885 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, |
e66f17ff | 4886 | pmd_t *pmd, int flags) |
9e5fc74c | 4887 | { |
e66f17ff NH |
4888 | struct page *page = NULL; |
4889 | spinlock_t *ptl; | |
c9d398fa | 4890 | pte_t pte; |
e66f17ff NH |
4891 | retry: |
4892 | ptl = pmd_lockptr(mm, pmd); | |
4893 | spin_lock(ptl); | |
4894 | /* | |
4895 | * make sure that the address range covered by this pmd is not | |
4896 | * unmapped from other threads. | |
4897 | */ | |
4898 | if (!pmd_huge(*pmd)) | |
4899 | goto out; | |
c9d398fa NH |
4900 | pte = huge_ptep_get((pte_t *)pmd); |
4901 | if (pte_present(pte)) { | |
97534127 | 4902 | page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); |
e66f17ff NH |
4903 | if (flags & FOLL_GET) |
4904 | get_page(page); | |
4905 | } else { | |
c9d398fa | 4906 | if (is_hugetlb_entry_migration(pte)) { |
e66f17ff NH |
4907 | spin_unlock(ptl); |
4908 | __migration_entry_wait(mm, (pte_t *)pmd, ptl); | |
4909 | goto retry; | |
4910 | } | |
4911 | /* | |
4912 | * hwpoisoned entry is treated as no_page_table in | |
4913 | * follow_page_mask(). | |
4914 | */ | |
4915 | } | |
4916 | out: | |
4917 | spin_unlock(ptl); | |
9e5fc74c SC |
4918 | return page; |
4919 | } | |
4920 | ||
61f77eda | 4921 | struct page * __weak |
9e5fc74c | 4922 | follow_huge_pud(struct mm_struct *mm, unsigned long address, |
e66f17ff | 4923 | pud_t *pud, int flags) |
9e5fc74c | 4924 | { |
e66f17ff NH |
4925 | if (flags & FOLL_GET) |
4926 | return NULL; | |
9e5fc74c | 4927 | |
e66f17ff | 4928 | return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); |
9e5fc74c SC |
4929 | } |
4930 | ||
faaa5b62 AK |
4931 | struct page * __weak |
4932 | follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) | |
4933 | { | |
4934 | if (flags & FOLL_GET) | |
4935 | return NULL; | |
4936 | ||
4937 | return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); | |
4938 | } | |
4939 | ||
31caf665 NH |
4940 | bool isolate_huge_page(struct page *page, struct list_head *list) |
4941 | { | |
bcc54222 NH |
4942 | bool ret = true; |
4943 | ||
309381fe | 4944 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 | 4945 | spin_lock(&hugetlb_lock); |
bcc54222 NH |
4946 | if (!page_huge_active(page) || !get_page_unless_zero(page)) { |
4947 | ret = false; | |
4948 | goto unlock; | |
4949 | } | |
4950 | clear_page_huge_active(page); | |
31caf665 | 4951 | list_move_tail(&page->lru, list); |
bcc54222 | 4952 | unlock: |
31caf665 | 4953 | spin_unlock(&hugetlb_lock); |
bcc54222 | 4954 | return ret; |
31caf665 NH |
4955 | } |
4956 | ||
4957 | void putback_active_hugepage(struct page *page) | |
4958 | { | |
309381fe | 4959 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 | 4960 | spin_lock(&hugetlb_lock); |
bcc54222 | 4961 | set_page_huge_active(page); |
31caf665 NH |
4962 | list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); |
4963 | spin_unlock(&hugetlb_lock); | |
4964 | put_page(page); | |
4965 | } | |
ab5ac90a MH |
4966 | |
4967 | void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) | |
4968 | { | |
4969 | struct hstate *h = page_hstate(oldpage); | |
4970 | ||
4971 | hugetlb_cgroup_migrate(oldpage, newpage); | |
4972 | set_page_owner_migrate_reason(newpage, reason); | |
4973 | ||
4974 | /* | |
4975 | * transfer temporary state of the new huge page. This is | |
4976 | * reverse to other transitions because the newpage is going to | |
4977 | * be final while the old one will be freed so it takes over | |
4978 | * the temporary status. | |
4979 | * | |
4980 | * Also note that we have to transfer the per-node surplus state | |
4981 | * here as well otherwise the global surplus count will not match | |
4982 | * the per-node's. | |
4983 | */ | |
4984 | if (PageHugeTemporary(newpage)) { | |
4985 | int old_nid = page_to_nid(oldpage); | |
4986 | int new_nid = page_to_nid(newpage); | |
4987 | ||
4988 | SetPageHugeTemporary(oldpage); | |
4989 | ClearPageHugeTemporary(newpage); | |
4990 | ||
4991 | spin_lock(&hugetlb_lock); | |
4992 | if (h->surplus_huge_pages_node[old_nid]) { | |
4993 | h->surplus_huge_pages_node[old_nid]--; | |
4994 | h->surplus_huge_pages_node[new_nid]++; | |
4995 | } | |
4996 | spin_unlock(&hugetlb_lock); | |
4997 | } | |
4998 | } |