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20c8ccb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
71e3aac0 AA |
2 | /* |
3 | * Copyright (C) 2009 Red Hat, Inc. | |
71e3aac0 AA |
4 | */ |
5 | ||
ae3a8c1c AM |
6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7 | ||
71e3aac0 AA |
8 | #include <linux/mm.h> |
9 | #include <linux/sched.h> | |
fa6c0231 | 10 | #include <linux/sched/mm.h> |
f7ccbae4 | 11 | #include <linux/sched/coredump.h> |
6a3827d7 | 12 | #include <linux/sched/numa_balancing.h> |
71e3aac0 AA |
13 | #include <linux/highmem.h> |
14 | #include <linux/hugetlb.h> | |
15 | #include <linux/mmu_notifier.h> | |
16 | #include <linux/rmap.h> | |
17 | #include <linux/swap.h> | |
97ae1749 | 18 | #include <linux/shrinker.h> |
ba76149f | 19 | #include <linux/mm_inline.h> |
e9b61f19 | 20 | #include <linux/swapops.h> |
fb5c2029 | 21 | #include <linux/backing-dev.h> |
4897c765 | 22 | #include <linux/dax.h> |
ba76149f | 23 | #include <linux/khugepaged.h> |
878aee7d | 24 | #include <linux/freezer.h> |
f25748e3 | 25 | #include <linux/pfn_t.h> |
a664b2d8 | 26 | #include <linux/mman.h> |
3565fce3 | 27 | #include <linux/memremap.h> |
325adeb5 | 28 | #include <linux/pagemap.h> |
49071d43 | 29 | #include <linux/debugfs.h> |
4daae3b4 | 30 | #include <linux/migrate.h> |
43b5fbbd | 31 | #include <linux/hashtable.h> |
6b251fc9 | 32 | #include <linux/userfaultfd_k.h> |
33c3fc71 | 33 | #include <linux/page_idle.h> |
baa355fd | 34 | #include <linux/shmem_fs.h> |
6b31d595 | 35 | #include <linux/oom.h> |
98fa15f3 | 36 | #include <linux/numa.h> |
f7da677b | 37 | #include <linux/page_owner.h> |
a1a3a2fc | 38 | #include <linux/sched/sysctl.h> |
467b171a | 39 | #include <linux/memory-tiers.h> |
4ef9ad19 | 40 | #include <linux/compat.h> |
97ae1749 | 41 | |
71e3aac0 AA |
42 | #include <asm/tlb.h> |
43 | #include <asm/pgalloc.h> | |
44 | #include "internal.h" | |
014bb1de | 45 | #include "swap.h" |
71e3aac0 | 46 | |
283fd6fe AK |
47 | #define CREATE_TRACE_POINTS |
48 | #include <trace/events/thp.h> | |
49 | ||
ba76149f | 50 | /* |
b14d595a MD |
51 | * By default, transparent hugepage support is disabled in order to avoid |
52 | * risking an increased memory footprint for applications that are not | |
53 | * guaranteed to benefit from it. When transparent hugepage support is | |
54 | * enabled, it is for all mappings, and khugepaged scans all mappings. | |
8bfa3f9a JW |
55 | * Defrag is invoked by khugepaged hugepage allocations and by page faults |
56 | * for all hugepage allocations. | |
ba76149f | 57 | */ |
71e3aac0 | 58 | unsigned long transparent_hugepage_flags __read_mostly = |
13ece886 | 59 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS |
ba76149f | 60 | (1<<TRANSPARENT_HUGEPAGE_FLAG)| |
13ece886 AA |
61 | #endif |
62 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE | |
63 | (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)| | |
64 | #endif | |
444eb2a4 | 65 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)| |
79da5407 KS |
66 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)| |
67 | (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); | |
ba76149f | 68 | |
54d91729 QZ |
69 | static struct shrinker *deferred_split_shrinker; |
70 | static unsigned long deferred_split_count(struct shrinker *shrink, | |
71 | struct shrink_control *sc); | |
72 | static unsigned long deferred_split_scan(struct shrinker *shrink, | |
73 | struct shrink_control *sc); | |
f000565a | 74 | |
97ae1749 | 75 | static atomic_t huge_zero_refcount; |
56873f43 | 76 | struct page *huge_zero_page __read_mostly; |
3b77e8c8 | 77 | unsigned long huge_zero_pfn __read_mostly = ~0UL; |
3485b883 RR |
78 | unsigned long huge_anon_orders_always __read_mostly; |
79 | unsigned long huge_anon_orders_madvise __read_mostly; | |
80 | unsigned long huge_anon_orders_inherit __read_mostly; | |
81 | ||
82 | unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, | |
83 | unsigned long vm_flags, bool smaps, | |
84 | bool in_pf, bool enforce_sysfs, | |
85 | unsigned long orders) | |
86 | { | |
87 | /* Check the intersection of requested and supported orders. */ | |
88 | orders &= vma_is_anonymous(vma) ? | |
89 | THP_ORDERS_ALL_ANON : THP_ORDERS_ALL_FILE; | |
90 | if (!orders) | |
91 | return 0; | |
4a6c1297 | 92 | |
9fec5168 | 93 | if (!vma->vm_mm) /* vdso */ |
3485b883 | 94 | return 0; |
9fec5168 | 95 | |
7da4e2cb YS |
96 | /* |
97 | * Explicitly disabled through madvise or prctl, or some | |
98 | * architectures may disable THP for some mappings, for | |
99 | * example, s390 kvm. | |
100 | * */ | |
101 | if ((vm_flags & VM_NOHUGEPAGE) || | |
102 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) | |
3485b883 | 103 | return 0; |
7da4e2cb YS |
104 | /* |
105 | * If the hardware/firmware marked hugepage support disabled. | |
106 | */ | |
3c556d24 | 107 | if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED)) |
3485b883 | 108 | return 0; |
c0630669 | 109 | |
7da4e2cb | 110 | /* khugepaged doesn't collapse DAX vma, but page fault is fine. */ |
9fec5168 | 111 | if (vma_is_dax(vma)) |
3485b883 | 112 | return in_pf ? orders : 0; |
7da4e2cb YS |
113 | |
114 | /* | |
7a81751f | 115 | * khugepaged special VMA and hugetlb VMA. |
7da4e2cb YS |
116 | * Must be checked after dax since some dax mappings may have |
117 | * VM_MIXEDMAP set. | |
118 | */ | |
7a81751f | 119 | if (!in_pf && !smaps && (vm_flags & VM_NO_KHUGEPAGED)) |
3485b883 | 120 | return 0; |
9fec5168 | 121 | |
7da4e2cb | 122 | /* |
3485b883 RR |
123 | * Check alignment for file vma and size for both file and anon vma by |
124 | * filtering out the unsuitable orders. | |
7da4e2cb YS |
125 | * |
126 | * Skip the check for page fault. Huge fault does the check in fault | |
3485b883 | 127 | * handlers. |
7da4e2cb | 128 | */ |
3485b883 RR |
129 | if (!in_pf) { |
130 | int order = highest_order(orders); | |
131 | unsigned long addr; | |
132 | ||
133 | while (orders) { | |
134 | addr = vma->vm_end - (PAGE_SIZE << order); | |
135 | if (thp_vma_suitable_order(vma, addr, order)) | |
136 | break; | |
137 | order = next_order(&orders, order); | |
138 | } | |
139 | ||
140 | if (!orders) | |
141 | return 0; | |
142 | } | |
9fec5168 | 143 | |
7da4e2cb YS |
144 | /* |
145 | * Enabled via shmem mount options or sysfs settings. | |
146 | * Must be done before hugepage flags check since shmem has its | |
147 | * own flags. | |
148 | */ | |
149 | if (!in_pf && shmem_file(vma->vm_file)) | |
2cf13384 | 150 | return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff, |
3485b883 RR |
151 | !enforce_sysfs, vma->vm_mm, vm_flags) |
152 | ? orders : 0; | |
9fec5168 | 153 | |
7a81751f | 154 | if (!vma_is_anonymous(vma)) { |
3485b883 RR |
155 | /* |
156 | * Enforce sysfs THP requirements as necessary. Anonymous vmas | |
157 | * were already handled in thp_vma_allowable_orders(). | |
158 | */ | |
159 | if (enforce_sysfs && | |
160 | (!hugepage_global_enabled() || (!(vm_flags & VM_HUGEPAGE) && | |
161 | !hugepage_global_always()))) | |
162 | return 0; | |
163 | ||
7a81751f ZK |
164 | /* |
165 | * Trust that ->huge_fault() handlers know what they are doing | |
166 | * in fault path. | |
167 | */ | |
168 | if (((in_pf || smaps)) && vma->vm_ops->huge_fault) | |
3485b883 | 169 | return orders; |
7a81751f ZK |
170 | /* Only regular file is valid in collapse path */ |
171 | if (((!in_pf || smaps)) && file_thp_enabled(vma)) | |
3485b883 RR |
172 | return orders; |
173 | return 0; | |
7a81751f | 174 | } |
9fec5168 YS |
175 | |
176 | if (vma_is_temporary_stack(vma)) | |
3485b883 | 177 | return 0; |
9fec5168 YS |
178 | |
179 | /* | |
180 | * THPeligible bit of smaps should show 1 for proper VMAs even | |
181 | * though anon_vma is not initialized yet. | |
7da4e2cb YS |
182 | * |
183 | * Allow page fault since anon_vma may be not initialized until | |
184 | * the first page fault. | |
9fec5168 YS |
185 | */ |
186 | if (!vma->anon_vma) | |
3485b883 | 187 | return (smaps || in_pf) ? orders : 0; |
9fec5168 | 188 | |
3485b883 | 189 | return orders; |
7635d9cb MH |
190 | } |
191 | ||
aaa9705b | 192 | static bool get_huge_zero_page(void) |
97ae1749 KS |
193 | { |
194 | struct page *zero_page; | |
195 | retry: | |
196 | if (likely(atomic_inc_not_zero(&huge_zero_refcount))) | |
aaa9705b | 197 | return true; |
97ae1749 KS |
198 | |
199 | zero_page = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE, | |
4a6c1297 | 200 | HPAGE_PMD_ORDER); |
d8a8e1f0 KS |
201 | if (!zero_page) { |
202 | count_vm_event(THP_ZERO_PAGE_ALLOC_FAILED); | |
aaa9705b | 203 | return false; |
d8a8e1f0 | 204 | } |
97ae1749 | 205 | preempt_disable(); |
5918d10a | 206 | if (cmpxchg(&huge_zero_page, NULL, zero_page)) { |
97ae1749 | 207 | preempt_enable(); |
5ddacbe9 | 208 | __free_pages(zero_page, compound_order(zero_page)); |
97ae1749 KS |
209 | goto retry; |
210 | } | |
3b77e8c8 | 211 | WRITE_ONCE(huge_zero_pfn, page_to_pfn(zero_page)); |
97ae1749 KS |
212 | |
213 | /* We take additional reference here. It will be put back by shrinker */ | |
214 | atomic_set(&huge_zero_refcount, 2); | |
215 | preempt_enable(); | |
f4981502 | 216 | count_vm_event(THP_ZERO_PAGE_ALLOC); |
aaa9705b | 217 | return true; |
4a6c1297 KS |
218 | } |
219 | ||
6fcb52a5 | 220 | static void put_huge_zero_page(void) |
4a6c1297 | 221 | { |
97ae1749 KS |
222 | /* |
223 | * Counter should never go to zero here. Only shrinker can put | |
224 | * last reference. | |
225 | */ | |
226 | BUG_ON(atomic_dec_and_test(&huge_zero_refcount)); | |
4a6c1297 KS |
227 | } |
228 | ||
6fcb52a5 AL |
229 | struct page *mm_get_huge_zero_page(struct mm_struct *mm) |
230 | { | |
231 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
232 | return READ_ONCE(huge_zero_page); | |
233 | ||
234 | if (!get_huge_zero_page()) | |
235 | return NULL; | |
236 | ||
237 | if (test_and_set_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
238 | put_huge_zero_page(); | |
239 | ||
240 | return READ_ONCE(huge_zero_page); | |
241 | } | |
242 | ||
243 | void mm_put_huge_zero_page(struct mm_struct *mm) | |
244 | { | |
245 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
246 | put_huge_zero_page(); | |
247 | } | |
248 | ||
48896466 GC |
249 | static unsigned long shrink_huge_zero_page_count(struct shrinker *shrink, |
250 | struct shrink_control *sc) | |
4a6c1297 | 251 | { |
48896466 GC |
252 | /* we can free zero page only if last reference remains */ |
253 | return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0; | |
254 | } | |
97ae1749 | 255 | |
48896466 GC |
256 | static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink, |
257 | struct shrink_control *sc) | |
258 | { | |
97ae1749 | 259 | if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) { |
5918d10a KS |
260 | struct page *zero_page = xchg(&huge_zero_page, NULL); |
261 | BUG_ON(zero_page == NULL); | |
3b77e8c8 | 262 | WRITE_ONCE(huge_zero_pfn, ~0UL); |
5ddacbe9 | 263 | __free_pages(zero_page, compound_order(zero_page)); |
48896466 | 264 | return HPAGE_PMD_NR; |
97ae1749 KS |
265 | } |
266 | ||
267 | return 0; | |
4a6c1297 KS |
268 | } |
269 | ||
54d91729 | 270 | static struct shrinker *huge_zero_page_shrinker; |
97ae1749 | 271 | |
71e3aac0 | 272 | #ifdef CONFIG_SYSFS |
71e3aac0 AA |
273 | static ssize_t enabled_show(struct kobject *kobj, |
274 | struct kobj_attribute *attr, char *buf) | |
275 | { | |
bfb0ffeb JP |
276 | const char *output; |
277 | ||
444eb2a4 | 278 | if (test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags)) |
bfb0ffeb JP |
279 | output = "[always] madvise never"; |
280 | else if (test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
281 | &transparent_hugepage_flags)) | |
282 | output = "always [madvise] never"; | |
444eb2a4 | 283 | else |
bfb0ffeb JP |
284 | output = "always madvise [never]"; |
285 | ||
286 | return sysfs_emit(buf, "%s\n", output); | |
71e3aac0 | 287 | } |
444eb2a4 | 288 | |
71e3aac0 AA |
289 | static ssize_t enabled_store(struct kobject *kobj, |
290 | struct kobj_attribute *attr, | |
291 | const char *buf, size_t count) | |
292 | { | |
21440d7e | 293 | ssize_t ret = count; |
ba76149f | 294 | |
f42f2552 | 295 | if (sysfs_streq(buf, "always")) { |
21440d7e DR |
296 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); |
297 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 298 | } else if (sysfs_streq(buf, "madvise")) { |
21440d7e DR |
299 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
300 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 301 | } else if (sysfs_streq(buf, "never")) { |
21440d7e DR |
302 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
303 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
304 | } else | |
305 | ret = -EINVAL; | |
ba76149f AA |
306 | |
307 | if (ret > 0) { | |
b46e756f | 308 | int err = start_stop_khugepaged(); |
ba76149f AA |
309 | if (err) |
310 | ret = err; | |
311 | } | |
ba76149f | 312 | return ret; |
71e3aac0 | 313 | } |
37139bb0 ML |
314 | |
315 | static struct kobj_attribute enabled_attr = __ATTR_RW(enabled); | |
71e3aac0 | 316 | |
b46e756f | 317 | ssize_t single_hugepage_flag_show(struct kobject *kobj, |
bfb0ffeb JP |
318 | struct kobj_attribute *attr, char *buf, |
319 | enum transparent_hugepage_flag flag) | |
71e3aac0 | 320 | { |
bfb0ffeb JP |
321 | return sysfs_emit(buf, "%d\n", |
322 | !!test_bit(flag, &transparent_hugepage_flags)); | |
71e3aac0 | 323 | } |
e27e6151 | 324 | |
b46e756f | 325 | ssize_t single_hugepage_flag_store(struct kobject *kobj, |
71e3aac0 AA |
326 | struct kobj_attribute *attr, |
327 | const char *buf, size_t count, | |
328 | enum transparent_hugepage_flag flag) | |
329 | { | |
e27e6151 BH |
330 | unsigned long value; |
331 | int ret; | |
332 | ||
333 | ret = kstrtoul(buf, 10, &value); | |
334 | if (ret < 0) | |
335 | return ret; | |
336 | if (value > 1) | |
337 | return -EINVAL; | |
338 | ||
339 | if (value) | |
71e3aac0 | 340 | set_bit(flag, &transparent_hugepage_flags); |
e27e6151 | 341 | else |
71e3aac0 | 342 | clear_bit(flag, &transparent_hugepage_flags); |
71e3aac0 AA |
343 | |
344 | return count; | |
345 | } | |
346 | ||
71e3aac0 AA |
347 | static ssize_t defrag_show(struct kobject *kobj, |
348 | struct kobj_attribute *attr, char *buf) | |
349 | { | |
bfb0ffeb JP |
350 | const char *output; |
351 | ||
352 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, | |
353 | &transparent_hugepage_flags)) | |
354 | output = "[always] defer defer+madvise madvise never"; | |
355 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, | |
356 | &transparent_hugepage_flags)) | |
357 | output = "always [defer] defer+madvise madvise never"; | |
358 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, | |
359 | &transparent_hugepage_flags)) | |
360 | output = "always defer [defer+madvise] madvise never"; | |
361 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, | |
362 | &transparent_hugepage_flags)) | |
363 | output = "always defer defer+madvise [madvise] never"; | |
364 | else | |
365 | output = "always defer defer+madvise madvise [never]"; | |
366 | ||
367 | return sysfs_emit(buf, "%s\n", output); | |
71e3aac0 | 368 | } |
21440d7e | 369 | |
71e3aac0 AA |
370 | static ssize_t defrag_store(struct kobject *kobj, |
371 | struct kobj_attribute *attr, | |
372 | const char *buf, size_t count) | |
373 | { | |
f42f2552 | 374 | if (sysfs_streq(buf, "always")) { |
21440d7e DR |
375 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
376 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
377 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
378 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 379 | } else if (sysfs_streq(buf, "defer+madvise")) { |
21440d7e DR |
380 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
381 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
382 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
383 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 384 | } else if (sysfs_streq(buf, "defer")) { |
4fad7fb6 DR |
385 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
386 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
387 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
388 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 389 | } else if (sysfs_streq(buf, "madvise")) { |
21440d7e DR |
390 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
391 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
392 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
393 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 394 | } else if (sysfs_streq(buf, "never")) { |
21440d7e DR |
395 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
396 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
397 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
398 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
399 | } else | |
400 | return -EINVAL; | |
401 | ||
402 | return count; | |
71e3aac0 | 403 | } |
37139bb0 | 404 | static struct kobj_attribute defrag_attr = __ATTR_RW(defrag); |
71e3aac0 | 405 | |
79da5407 | 406 | static ssize_t use_zero_page_show(struct kobject *kobj, |
ae7a927d | 407 | struct kobj_attribute *attr, char *buf) |
79da5407 | 408 | { |
b46e756f | 409 | return single_hugepage_flag_show(kobj, attr, buf, |
ae7a927d | 410 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
79da5407 KS |
411 | } |
412 | static ssize_t use_zero_page_store(struct kobject *kobj, | |
413 | struct kobj_attribute *attr, const char *buf, size_t count) | |
414 | { | |
b46e756f | 415 | return single_hugepage_flag_store(kobj, attr, buf, count, |
79da5407 KS |
416 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
417 | } | |
37139bb0 | 418 | static struct kobj_attribute use_zero_page_attr = __ATTR_RW(use_zero_page); |
49920d28 HD |
419 | |
420 | static ssize_t hpage_pmd_size_show(struct kobject *kobj, | |
ae7a927d | 421 | struct kobj_attribute *attr, char *buf) |
49920d28 | 422 | { |
ae7a927d | 423 | return sysfs_emit(buf, "%lu\n", HPAGE_PMD_SIZE); |
49920d28 HD |
424 | } |
425 | static struct kobj_attribute hpage_pmd_size_attr = | |
426 | __ATTR_RO(hpage_pmd_size); | |
427 | ||
71e3aac0 AA |
428 | static struct attribute *hugepage_attr[] = { |
429 | &enabled_attr.attr, | |
430 | &defrag_attr.attr, | |
79da5407 | 431 | &use_zero_page_attr.attr, |
49920d28 | 432 | &hpage_pmd_size_attr.attr, |
396bcc52 | 433 | #ifdef CONFIG_SHMEM |
5a6e75f8 | 434 | &shmem_enabled_attr.attr, |
71e3aac0 AA |
435 | #endif |
436 | NULL, | |
437 | }; | |
438 | ||
8aa95a21 | 439 | static const struct attribute_group hugepage_attr_group = { |
71e3aac0 | 440 | .attrs = hugepage_attr, |
ba76149f AA |
441 | }; |
442 | ||
3485b883 RR |
443 | static void hugepage_exit_sysfs(struct kobject *hugepage_kobj); |
444 | static void thpsize_release(struct kobject *kobj); | |
445 | static DEFINE_SPINLOCK(huge_anon_orders_lock); | |
446 | static LIST_HEAD(thpsize_list); | |
447 | ||
448 | struct thpsize { | |
449 | struct kobject kobj; | |
450 | struct list_head node; | |
451 | int order; | |
452 | }; | |
453 | ||
454 | #define to_thpsize(kobj) container_of(kobj, struct thpsize, kobj) | |
455 | ||
456 | static ssize_t thpsize_enabled_show(struct kobject *kobj, | |
457 | struct kobj_attribute *attr, char *buf) | |
458 | { | |
459 | int order = to_thpsize(kobj)->order; | |
460 | const char *output; | |
461 | ||
462 | if (test_bit(order, &huge_anon_orders_always)) | |
463 | output = "[always] inherit madvise never"; | |
464 | else if (test_bit(order, &huge_anon_orders_inherit)) | |
465 | output = "always [inherit] madvise never"; | |
466 | else if (test_bit(order, &huge_anon_orders_madvise)) | |
467 | output = "always inherit [madvise] never"; | |
468 | else | |
469 | output = "always inherit madvise [never]"; | |
470 | ||
471 | return sysfs_emit(buf, "%s\n", output); | |
472 | } | |
473 | ||
474 | static ssize_t thpsize_enabled_store(struct kobject *kobj, | |
475 | struct kobj_attribute *attr, | |
476 | const char *buf, size_t count) | |
477 | { | |
478 | int order = to_thpsize(kobj)->order; | |
479 | ssize_t ret = count; | |
480 | ||
481 | if (sysfs_streq(buf, "always")) { | |
482 | spin_lock(&huge_anon_orders_lock); | |
483 | clear_bit(order, &huge_anon_orders_inherit); | |
484 | clear_bit(order, &huge_anon_orders_madvise); | |
485 | set_bit(order, &huge_anon_orders_always); | |
486 | spin_unlock(&huge_anon_orders_lock); | |
487 | } else if (sysfs_streq(buf, "inherit")) { | |
488 | spin_lock(&huge_anon_orders_lock); | |
489 | clear_bit(order, &huge_anon_orders_always); | |
490 | clear_bit(order, &huge_anon_orders_madvise); | |
491 | set_bit(order, &huge_anon_orders_inherit); | |
492 | spin_unlock(&huge_anon_orders_lock); | |
493 | } else if (sysfs_streq(buf, "madvise")) { | |
494 | spin_lock(&huge_anon_orders_lock); | |
495 | clear_bit(order, &huge_anon_orders_always); | |
496 | clear_bit(order, &huge_anon_orders_inherit); | |
497 | set_bit(order, &huge_anon_orders_madvise); | |
498 | spin_unlock(&huge_anon_orders_lock); | |
499 | } else if (sysfs_streq(buf, "never")) { | |
500 | spin_lock(&huge_anon_orders_lock); | |
501 | clear_bit(order, &huge_anon_orders_always); | |
502 | clear_bit(order, &huge_anon_orders_inherit); | |
503 | clear_bit(order, &huge_anon_orders_madvise); | |
504 | spin_unlock(&huge_anon_orders_lock); | |
505 | } else | |
506 | ret = -EINVAL; | |
507 | ||
508 | return ret; | |
509 | } | |
510 | ||
511 | static struct kobj_attribute thpsize_enabled_attr = | |
512 | __ATTR(enabled, 0644, thpsize_enabled_show, thpsize_enabled_store); | |
513 | ||
514 | static struct attribute *thpsize_attrs[] = { | |
515 | &thpsize_enabled_attr.attr, | |
516 | NULL, | |
517 | }; | |
518 | ||
519 | static const struct attribute_group thpsize_attr_group = { | |
520 | .attrs = thpsize_attrs, | |
521 | }; | |
522 | ||
523 | static const struct kobj_type thpsize_ktype = { | |
524 | .release = &thpsize_release, | |
525 | .sysfs_ops = &kobj_sysfs_ops, | |
526 | }; | |
527 | ||
528 | static struct thpsize *thpsize_create(int order, struct kobject *parent) | |
529 | { | |
530 | unsigned long size = (PAGE_SIZE << order) / SZ_1K; | |
531 | struct thpsize *thpsize; | |
532 | int ret; | |
533 | ||
534 | thpsize = kzalloc(sizeof(*thpsize), GFP_KERNEL); | |
535 | if (!thpsize) | |
536 | return ERR_PTR(-ENOMEM); | |
537 | ||
538 | ret = kobject_init_and_add(&thpsize->kobj, &thpsize_ktype, parent, | |
539 | "hugepages-%lukB", size); | |
540 | if (ret) { | |
541 | kfree(thpsize); | |
542 | return ERR_PTR(ret); | |
543 | } | |
544 | ||
545 | ret = sysfs_create_group(&thpsize->kobj, &thpsize_attr_group); | |
546 | if (ret) { | |
547 | kobject_put(&thpsize->kobj); | |
548 | return ERR_PTR(ret); | |
549 | } | |
550 | ||
551 | thpsize->order = order; | |
552 | return thpsize; | |
553 | } | |
554 | ||
555 | static void thpsize_release(struct kobject *kobj) | |
556 | { | |
557 | kfree(to_thpsize(kobj)); | |
558 | } | |
559 | ||
569e5590 | 560 | static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) |
71e3aac0 | 561 | { |
71e3aac0 | 562 | int err; |
3485b883 RR |
563 | struct thpsize *thpsize; |
564 | unsigned long orders; | |
565 | int order; | |
566 | ||
567 | /* | |
568 | * Default to setting PMD-sized THP to inherit the global setting and | |
569 | * disable all other sizes. powerpc's PMD_ORDER isn't a compile-time | |
570 | * constant so we have to do this here. | |
571 | */ | |
572 | huge_anon_orders_inherit = BIT(PMD_ORDER); | |
71e3aac0 | 573 | |
569e5590 SL |
574 | *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj); |
575 | if (unlikely(!*hugepage_kobj)) { | |
ae3a8c1c | 576 | pr_err("failed to create transparent hugepage kobject\n"); |
569e5590 | 577 | return -ENOMEM; |
ba76149f AA |
578 | } |
579 | ||
569e5590 | 580 | err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group); |
ba76149f | 581 | if (err) { |
ae3a8c1c | 582 | pr_err("failed to register transparent hugepage group\n"); |
569e5590 | 583 | goto delete_obj; |
ba76149f AA |
584 | } |
585 | ||
569e5590 | 586 | err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group); |
ba76149f | 587 | if (err) { |
ae3a8c1c | 588 | pr_err("failed to register transparent hugepage group\n"); |
569e5590 | 589 | goto remove_hp_group; |
ba76149f | 590 | } |
569e5590 | 591 | |
3485b883 RR |
592 | orders = THP_ORDERS_ALL_ANON; |
593 | order = highest_order(orders); | |
594 | while (orders) { | |
595 | thpsize = thpsize_create(order, *hugepage_kobj); | |
596 | if (IS_ERR(thpsize)) { | |
597 | pr_err("failed to create thpsize for order %d\n", order); | |
598 | err = PTR_ERR(thpsize); | |
599 | goto remove_all; | |
600 | } | |
601 | list_add(&thpsize->node, &thpsize_list); | |
602 | order = next_order(&orders, order); | |
603 | } | |
604 | ||
569e5590 SL |
605 | return 0; |
606 | ||
3485b883 RR |
607 | remove_all: |
608 | hugepage_exit_sysfs(*hugepage_kobj); | |
609 | return err; | |
569e5590 SL |
610 | remove_hp_group: |
611 | sysfs_remove_group(*hugepage_kobj, &hugepage_attr_group); | |
612 | delete_obj: | |
613 | kobject_put(*hugepage_kobj); | |
614 | return err; | |
615 | } | |
616 | ||
617 | static void __init hugepage_exit_sysfs(struct kobject *hugepage_kobj) | |
618 | { | |
3485b883 RR |
619 | struct thpsize *thpsize, *tmp; |
620 | ||
621 | list_for_each_entry_safe(thpsize, tmp, &thpsize_list, node) { | |
622 | list_del(&thpsize->node); | |
623 | kobject_put(&thpsize->kobj); | |
624 | } | |
625 | ||
569e5590 SL |
626 | sysfs_remove_group(hugepage_kobj, &khugepaged_attr_group); |
627 | sysfs_remove_group(hugepage_kobj, &hugepage_attr_group); | |
628 | kobject_put(hugepage_kobj); | |
629 | } | |
630 | #else | |
631 | static inline int hugepage_init_sysfs(struct kobject **hugepage_kobj) | |
632 | { | |
633 | return 0; | |
634 | } | |
635 | ||
636 | static inline void hugepage_exit_sysfs(struct kobject *hugepage_kobj) | |
637 | { | |
638 | } | |
639 | #endif /* CONFIG_SYSFS */ | |
640 | ||
54d91729 QZ |
641 | static int __init thp_shrinker_init(void) |
642 | { | |
643 | huge_zero_page_shrinker = shrinker_alloc(0, "thp-zero"); | |
644 | if (!huge_zero_page_shrinker) | |
645 | return -ENOMEM; | |
646 | ||
647 | deferred_split_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE | | |
648 | SHRINKER_MEMCG_AWARE | | |
649 | SHRINKER_NONSLAB, | |
650 | "thp-deferred_split"); | |
651 | if (!deferred_split_shrinker) { | |
652 | shrinker_free(huge_zero_page_shrinker); | |
653 | return -ENOMEM; | |
654 | } | |
655 | ||
656 | huge_zero_page_shrinker->count_objects = shrink_huge_zero_page_count; | |
657 | huge_zero_page_shrinker->scan_objects = shrink_huge_zero_page_scan; | |
658 | shrinker_register(huge_zero_page_shrinker); | |
659 | ||
660 | deferred_split_shrinker->count_objects = deferred_split_count; | |
661 | deferred_split_shrinker->scan_objects = deferred_split_scan; | |
662 | shrinker_register(deferred_split_shrinker); | |
663 | ||
664 | return 0; | |
665 | } | |
666 | ||
667 | static void __init thp_shrinker_exit(void) | |
668 | { | |
669 | shrinker_free(huge_zero_page_shrinker); | |
670 | shrinker_free(deferred_split_shrinker); | |
671 | } | |
672 | ||
569e5590 SL |
673 | static int __init hugepage_init(void) |
674 | { | |
675 | int err; | |
676 | struct kobject *hugepage_kobj; | |
677 | ||
678 | if (!has_transparent_hugepage()) { | |
3c556d24 | 679 | transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED; |
569e5590 SL |
680 | return -EINVAL; |
681 | } | |
682 | ||
ff20c2e0 KS |
683 | /* |
684 | * hugepages can't be allocated by the buddy allocator | |
685 | */ | |
5e0a760b | 686 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER > MAX_PAGE_ORDER); |
ff20c2e0 KS |
687 | /* |
688 | * we use page->mapping and page->index in second tail page | |
689 | * as list_head: assuming THP order >= 2 | |
690 | */ | |
691 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER < 2); | |
692 | ||
569e5590 SL |
693 | err = hugepage_init_sysfs(&hugepage_kobj); |
694 | if (err) | |
65ebb64f | 695 | goto err_sysfs; |
ba76149f | 696 | |
b46e756f | 697 | err = khugepaged_init(); |
ba76149f | 698 | if (err) |
65ebb64f | 699 | goto err_slab; |
ba76149f | 700 | |
54d91729 | 701 | err = thp_shrinker_init(); |
9a982250 | 702 | if (err) |
54d91729 | 703 | goto err_shrinker; |
97ae1749 | 704 | |
97562cd2 RR |
705 | /* |
706 | * By default disable transparent hugepages on smaller systems, | |
707 | * where the extra memory used could hurt more than TLB overhead | |
708 | * is likely to save. The admin can still enable it through /sys. | |
709 | */ | |
ca79b0c2 | 710 | if (totalram_pages() < (512 << (20 - PAGE_SHIFT))) { |
97562cd2 | 711 | transparent_hugepage_flags = 0; |
79553da2 KS |
712 | return 0; |
713 | } | |
97562cd2 | 714 | |
79553da2 | 715 | err = start_stop_khugepaged(); |
65ebb64f KS |
716 | if (err) |
717 | goto err_khugepaged; | |
ba76149f | 718 | |
569e5590 | 719 | return 0; |
65ebb64f | 720 | err_khugepaged: |
54d91729 QZ |
721 | thp_shrinker_exit(); |
722 | err_shrinker: | |
b46e756f | 723 | khugepaged_destroy(); |
65ebb64f | 724 | err_slab: |
569e5590 | 725 | hugepage_exit_sysfs(hugepage_kobj); |
65ebb64f | 726 | err_sysfs: |
ba76149f | 727 | return err; |
71e3aac0 | 728 | } |
a64fb3cd | 729 | subsys_initcall(hugepage_init); |
71e3aac0 AA |
730 | |
731 | static int __init setup_transparent_hugepage(char *str) | |
732 | { | |
733 | int ret = 0; | |
734 | if (!str) | |
735 | goto out; | |
736 | if (!strcmp(str, "always")) { | |
737 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
738 | &transparent_hugepage_flags); | |
739 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
740 | &transparent_hugepage_flags); | |
741 | ret = 1; | |
742 | } else if (!strcmp(str, "madvise")) { | |
743 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
744 | &transparent_hugepage_flags); | |
745 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
746 | &transparent_hugepage_flags); | |
747 | ret = 1; | |
748 | } else if (!strcmp(str, "never")) { | |
749 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
750 | &transparent_hugepage_flags); | |
751 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
752 | &transparent_hugepage_flags); | |
753 | ret = 1; | |
754 | } | |
755 | out: | |
756 | if (!ret) | |
ae3a8c1c | 757 | pr_warn("transparent_hugepage= cannot parse, ignored\n"); |
71e3aac0 AA |
758 | return ret; |
759 | } | |
760 | __setup("transparent_hugepage=", setup_transparent_hugepage); | |
761 | ||
f55e1014 | 762 | pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) |
71e3aac0 | 763 | { |
f55e1014 | 764 | if (likely(vma->vm_flags & VM_WRITE)) |
161e393c | 765 | pmd = pmd_mkwrite(pmd, vma); |
71e3aac0 AA |
766 | return pmd; |
767 | } | |
768 | ||
87eaceb3 | 769 | #ifdef CONFIG_MEMCG |
f8baa6be MWO |
770 | static inline |
771 | struct deferred_split *get_deferred_split_queue(struct folio *folio) | |
9a982250 | 772 | { |
f8baa6be MWO |
773 | struct mem_cgroup *memcg = folio_memcg(folio); |
774 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); | |
87eaceb3 YS |
775 | |
776 | if (memcg) | |
777 | return &memcg->deferred_split_queue; | |
778 | else | |
779 | return &pgdat->deferred_split_queue; | |
9a982250 | 780 | } |
87eaceb3 | 781 | #else |
f8baa6be MWO |
782 | static inline |
783 | struct deferred_split *get_deferred_split_queue(struct folio *folio) | |
87eaceb3 | 784 | { |
f8baa6be | 785 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); |
87eaceb3 YS |
786 | |
787 | return &pgdat->deferred_split_queue; | |
788 | } | |
789 | #endif | |
9a982250 | 790 | |
da6e7bf3 | 791 | void folio_prep_large_rmappable(struct folio *folio) |
9a982250 | 792 | { |
8991de90 MWO |
793 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
794 | INIT_LIST_HEAD(&folio->_deferred_list); | |
de53c05f | 795 | folio_set_large_rmappable(folio); |
9a982250 KS |
796 | } |
797 | ||
a644b0ab | 798 | static inline bool is_transparent_hugepage(struct folio *folio) |
005ba37c | 799 | { |
a644b0ab | 800 | if (!folio_test_large(folio)) |
fa1f68cc | 801 | return false; |
005ba37c | 802 | |
f04029f3 | 803 | return is_huge_zero_page(&folio->page) || |
de53c05f | 804 | folio_test_large_rmappable(folio); |
005ba37c | 805 | } |
005ba37c | 806 | |
97d3d0f9 KS |
807 | static unsigned long __thp_get_unmapped_area(struct file *filp, |
808 | unsigned long addr, unsigned long len, | |
74d2fad1 TK |
809 | loff_t off, unsigned long flags, unsigned long size) |
810 | { | |
74d2fad1 TK |
811 | loff_t off_end = off + len; |
812 | loff_t off_align = round_up(off, size); | |
96204e15 | 813 | unsigned long len_pad, ret, off_sub; |
74d2fad1 | 814 | |
4ef9ad19 YS |
815 | if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall()) |
816 | return 0; | |
817 | ||
74d2fad1 TK |
818 | if (off_end <= off_align || (off_end - off_align) < size) |
819 | return 0; | |
820 | ||
821 | len_pad = len + size; | |
822 | if (len_pad < len || (off + len_pad) < off) | |
823 | return 0; | |
824 | ||
97d3d0f9 | 825 | ret = current->mm->get_unmapped_area(filp, addr, len_pad, |
74d2fad1 | 826 | off >> PAGE_SHIFT, flags); |
97d3d0f9 KS |
827 | |
828 | /* | |
829 | * The failure might be due to length padding. The caller will retry | |
830 | * without the padding. | |
831 | */ | |
832 | if (IS_ERR_VALUE(ret)) | |
74d2fad1 TK |
833 | return 0; |
834 | ||
97d3d0f9 KS |
835 | /* |
836 | * Do not try to align to THP boundary if allocation at the address | |
837 | * hint succeeds. | |
838 | */ | |
839 | if (ret == addr) | |
840 | return addr; | |
841 | ||
96204e15 RR |
842 | off_sub = (off - ret) & (size - 1); |
843 | ||
844 | if (current->mm->get_unmapped_area == arch_get_unmapped_area_topdown && | |
845 | !off_sub) | |
846 | return ret + size; | |
847 | ||
848 | ret += off_sub; | |
97d3d0f9 | 849 | return ret; |
74d2fad1 TK |
850 | } |
851 | ||
852 | unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, | |
853 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
854 | { | |
97d3d0f9 | 855 | unsigned long ret; |
74d2fad1 TK |
856 | loff_t off = (loff_t)pgoff << PAGE_SHIFT; |
857 | ||
97d3d0f9 KS |
858 | ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE); |
859 | if (ret) | |
860 | return ret; | |
1854bc6e | 861 | |
74d2fad1 TK |
862 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); |
863 | } | |
864 | EXPORT_SYMBOL_GPL(thp_get_unmapped_area); | |
865 | ||
2b740303 SJ |
866 | static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, |
867 | struct page *page, gfp_t gfp) | |
71e3aac0 | 868 | { |
82b0f8c3 | 869 | struct vm_area_struct *vma = vmf->vma; |
cfe3236d | 870 | struct folio *folio = page_folio(page); |
71e3aac0 | 871 | pgtable_t pgtable; |
82b0f8c3 | 872 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
2b740303 | 873 | vm_fault_t ret = 0; |
71e3aac0 | 874 | |
cfe3236d | 875 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
00501b53 | 876 | |
cfe3236d KW |
877 | if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { |
878 | folio_put(folio); | |
6b251fc9 | 879 | count_vm_event(THP_FAULT_FALLBACK); |
85b9f46e | 880 | count_vm_event(THP_FAULT_FALLBACK_CHARGE); |
6b251fc9 AA |
881 | return VM_FAULT_FALLBACK; |
882 | } | |
cfe3236d | 883 | folio_throttle_swaprate(folio, gfp); |
00501b53 | 884 | |
4cf58924 | 885 | pgtable = pte_alloc_one(vma->vm_mm); |
00501b53 | 886 | if (unlikely(!pgtable)) { |
6b31d595 MH |
887 | ret = VM_FAULT_OOM; |
888 | goto release; | |
00501b53 | 889 | } |
71e3aac0 | 890 | |
c79b57e4 | 891 | clear_huge_page(page, vmf->address, HPAGE_PMD_NR); |
52f37629 | 892 | /* |
cfe3236d | 893 | * The memory barrier inside __folio_mark_uptodate makes sure that |
52f37629 MK |
894 | * clear_huge_page writes become visible before the set_pmd_at() |
895 | * write. | |
896 | */ | |
cfe3236d | 897 | __folio_mark_uptodate(folio); |
71e3aac0 | 898 | |
82b0f8c3 JK |
899 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
900 | if (unlikely(!pmd_none(*vmf->pmd))) { | |
6b31d595 | 901 | goto unlock_release; |
71e3aac0 AA |
902 | } else { |
903 | pmd_t entry; | |
6b251fc9 | 904 | |
6b31d595 MH |
905 | ret = check_stable_address_space(vma->vm_mm); |
906 | if (ret) | |
907 | goto unlock_release; | |
908 | ||
6b251fc9 AA |
909 | /* Deliver the page fault to userland */ |
910 | if (userfaultfd_missing(vma)) { | |
82b0f8c3 | 911 | spin_unlock(vmf->ptl); |
cfe3236d | 912 | folio_put(folio); |
bae473a4 | 913 | pte_free(vma->vm_mm, pgtable); |
8fd5eda4 ML |
914 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
915 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); | |
916 | return ret; | |
6b251fc9 AA |
917 | } |
918 | ||
3122359a | 919 | entry = mk_huge_pmd(page, vma->vm_page_prot); |
f55e1014 | 920 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
cfe3236d KW |
921 | folio_add_new_anon_rmap(folio, vma, haddr); |
922 | folio_add_lru_vma(folio, vma); | |
82b0f8c3 JK |
923 | pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); |
924 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); | |
fca40573 | 925 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
bae473a4 | 926 | add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
c4812909 | 927 | mm_inc_nr_ptes(vma->vm_mm); |
82b0f8c3 | 928 | spin_unlock(vmf->ptl); |
6b251fc9 | 929 | count_vm_event(THP_FAULT_ALLOC); |
9d82c694 | 930 | count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); |
71e3aac0 AA |
931 | } |
932 | ||
aa2e878e | 933 | return 0; |
6b31d595 MH |
934 | unlock_release: |
935 | spin_unlock(vmf->ptl); | |
936 | release: | |
937 | if (pgtable) | |
938 | pte_free(vma->vm_mm, pgtable); | |
cfe3236d | 939 | folio_put(folio); |
6b31d595 MH |
940 | return ret; |
941 | ||
71e3aac0 AA |
942 | } |
943 | ||
444eb2a4 | 944 | /* |
21440d7e DR |
945 | * always: directly stall for all thp allocations |
946 | * defer: wake kswapd and fail if not immediately available | |
947 | * defer+madvise: wake kswapd and directly stall for MADV_HUGEPAGE, otherwise | |
948 | * fail if not immediately available | |
949 | * madvise: directly stall for MADV_HUGEPAGE, otherwise fail if not immediately | |
950 | * available | |
951 | * never: never stall for any thp allocation | |
444eb2a4 | 952 | */ |
164cc4fe | 953 | gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma) |
444eb2a4 | 954 | { |
164cc4fe | 955 | const bool vma_madvised = vma && (vma->vm_flags & VM_HUGEPAGE); |
2f0799a0 | 956 | |
ac79f78d | 957 | /* Always do synchronous compaction */ |
a8282608 AA |
958 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags)) |
959 | return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY); | |
ac79f78d DR |
960 | |
961 | /* Kick kcompactd and fail quickly */ | |
21440d7e | 962 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags)) |
19deb769 | 963 | return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM; |
ac79f78d DR |
964 | |
965 | /* Synchronous compaction if madvised, otherwise kick kcompactd */ | |
21440d7e | 966 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags)) |
19deb769 DR |
967 | return GFP_TRANSHUGE_LIGHT | |
968 | (vma_madvised ? __GFP_DIRECT_RECLAIM : | |
969 | __GFP_KSWAPD_RECLAIM); | |
ac79f78d DR |
970 | |
971 | /* Only do synchronous compaction if madvised */ | |
21440d7e | 972 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags)) |
19deb769 DR |
973 | return GFP_TRANSHUGE_LIGHT | |
974 | (vma_madvised ? __GFP_DIRECT_RECLAIM : 0); | |
ac79f78d | 975 | |
19deb769 | 976 | return GFP_TRANSHUGE_LIGHT; |
444eb2a4 MG |
977 | } |
978 | ||
c4088ebd | 979 | /* Caller must hold page table lock. */ |
2efeb8da | 980 | static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm, |
97ae1749 | 981 | struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd, |
5918d10a | 982 | struct page *zero_page) |
fc9fe822 KS |
983 | { |
984 | pmd_t entry; | |
7c414164 | 985 | if (!pmd_none(*pmd)) |
2efeb8da | 986 | return; |
5918d10a | 987 | entry = mk_pmd(zero_page, vma->vm_page_prot); |
fc9fe822 | 988 | entry = pmd_mkhuge(entry); |
c8bb4163 | 989 | pgtable_trans_huge_deposit(mm, pmd, pgtable); |
fc9fe822 | 990 | set_pmd_at(mm, haddr, pmd, entry); |
c4812909 | 991 | mm_inc_nr_ptes(mm); |
fc9fe822 KS |
992 | } |
993 | ||
2b740303 | 994 | vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf) |
71e3aac0 | 995 | { |
82b0f8c3 | 996 | struct vm_area_struct *vma = vmf->vma; |
077fcf11 | 997 | gfp_t gfp; |
cb196ee1 | 998 | struct folio *folio; |
82b0f8c3 | 999 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
71e3aac0 | 1000 | |
3485b883 | 1001 | if (!thp_vma_suitable_order(vma, haddr, PMD_ORDER)) |
c0292554 | 1002 | return VM_FAULT_FALLBACK; |
128ec037 KS |
1003 | if (unlikely(anon_vma_prepare(vma))) |
1004 | return VM_FAULT_OOM; | |
4fa6893f | 1005 | khugepaged_enter_vma(vma, vma->vm_flags); |
d2081b2b | 1006 | |
82b0f8c3 | 1007 | if (!(vmf->flags & FAULT_FLAG_WRITE) && |
bae473a4 | 1008 | !mm_forbids_zeropage(vma->vm_mm) && |
128ec037 KS |
1009 | transparent_hugepage_use_zero_page()) { |
1010 | pgtable_t pgtable; | |
1011 | struct page *zero_page; | |
2b740303 | 1012 | vm_fault_t ret; |
4cf58924 | 1013 | pgtable = pte_alloc_one(vma->vm_mm); |
128ec037 | 1014 | if (unlikely(!pgtable)) |
ba76149f | 1015 | return VM_FAULT_OOM; |
6fcb52a5 | 1016 | zero_page = mm_get_huge_zero_page(vma->vm_mm); |
128ec037 | 1017 | if (unlikely(!zero_page)) { |
bae473a4 | 1018 | pte_free(vma->vm_mm, pgtable); |
81ab4201 | 1019 | count_vm_event(THP_FAULT_FALLBACK); |
c0292554 | 1020 | return VM_FAULT_FALLBACK; |
b9bbfbe3 | 1021 | } |
82b0f8c3 | 1022 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
6b251fc9 | 1023 | ret = 0; |
82b0f8c3 | 1024 | if (pmd_none(*vmf->pmd)) { |
6b31d595 MH |
1025 | ret = check_stable_address_space(vma->vm_mm); |
1026 | if (ret) { | |
1027 | spin_unlock(vmf->ptl); | |
bfe8cc1d | 1028 | pte_free(vma->vm_mm, pgtable); |
6b31d595 | 1029 | } else if (userfaultfd_missing(vma)) { |
82b0f8c3 | 1030 | spin_unlock(vmf->ptl); |
bfe8cc1d | 1031 | pte_free(vma->vm_mm, pgtable); |
82b0f8c3 | 1032 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
6b251fc9 AA |
1033 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); |
1034 | } else { | |
bae473a4 | 1035 | set_huge_zero_page(pgtable, vma->vm_mm, vma, |
82b0f8c3 | 1036 | haddr, vmf->pmd, zero_page); |
fca40573 | 1037 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
82b0f8c3 | 1038 | spin_unlock(vmf->ptl); |
6b251fc9 | 1039 | } |
bfe8cc1d | 1040 | } else { |
82b0f8c3 | 1041 | spin_unlock(vmf->ptl); |
bae473a4 | 1042 | pte_free(vma->vm_mm, pgtable); |
bfe8cc1d | 1043 | } |
6b251fc9 | 1044 | return ret; |
71e3aac0 | 1045 | } |
164cc4fe | 1046 | gfp = vma_thp_gfp_mask(vma); |
cb196ee1 MWO |
1047 | folio = vma_alloc_folio(gfp, HPAGE_PMD_ORDER, vma, haddr, true); |
1048 | if (unlikely(!folio)) { | |
128ec037 | 1049 | count_vm_event(THP_FAULT_FALLBACK); |
c0292554 | 1050 | return VM_FAULT_FALLBACK; |
128ec037 | 1051 | } |
cb196ee1 | 1052 | return __do_huge_pmd_anonymous_page(vmf, &folio->page, gfp); |
71e3aac0 AA |
1053 | } |
1054 | ||
ae18d6dc | 1055 | static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, |
3b6521f5 OH |
1056 | pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write, |
1057 | pgtable_t pgtable) | |
5cad465d MW |
1058 | { |
1059 | struct mm_struct *mm = vma->vm_mm; | |
1060 | pmd_t entry; | |
1061 | spinlock_t *ptl; | |
1062 | ||
1063 | ptl = pmd_lock(mm, pmd); | |
c6f3c5ee AK |
1064 | if (!pmd_none(*pmd)) { |
1065 | if (write) { | |
1066 | if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { | |
1067 | WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); | |
1068 | goto out_unlock; | |
1069 | } | |
1070 | entry = pmd_mkyoung(*pmd); | |
1071 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); | |
1072 | if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) | |
1073 | update_mmu_cache_pmd(vma, addr, pmd); | |
1074 | } | |
1075 | ||
1076 | goto out_unlock; | |
1077 | } | |
1078 | ||
f25748e3 DW |
1079 | entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); |
1080 | if (pfn_t_devmap(pfn)) | |
1081 | entry = pmd_mkdevmap(entry); | |
01871e59 | 1082 | if (write) { |
f55e1014 LT |
1083 | entry = pmd_mkyoung(pmd_mkdirty(entry)); |
1084 | entry = maybe_pmd_mkwrite(entry, vma); | |
5cad465d | 1085 | } |
3b6521f5 OH |
1086 | |
1087 | if (pgtable) { | |
1088 | pgtable_trans_huge_deposit(mm, pmd, pgtable); | |
c4812909 | 1089 | mm_inc_nr_ptes(mm); |
c6f3c5ee | 1090 | pgtable = NULL; |
3b6521f5 OH |
1091 | } |
1092 | ||
01871e59 RZ |
1093 | set_pmd_at(mm, addr, pmd, entry); |
1094 | update_mmu_cache_pmd(vma, addr, pmd); | |
c6f3c5ee AK |
1095 | |
1096 | out_unlock: | |
5cad465d | 1097 | spin_unlock(ptl); |
c6f3c5ee AK |
1098 | if (pgtable) |
1099 | pte_free(mm, pgtable); | |
5cad465d MW |
1100 | } |
1101 | ||
9a9731b1 | 1102 | /** |
7b806d22 | 1103 | * vmf_insert_pfn_pmd - insert a pmd size pfn |
9a9731b1 THV |
1104 | * @vmf: Structure describing the fault |
1105 | * @pfn: pfn to insert | |
9a9731b1 THV |
1106 | * @write: whether it's a write fault |
1107 | * | |
7b806d22 | 1108 | * Insert a pmd size pfn. See vmf_insert_pfn() for additional info. |
9a9731b1 THV |
1109 | * |
1110 | * Return: vm_fault_t value. | |
1111 | */ | |
7b806d22 | 1112 | vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write) |
5cad465d | 1113 | { |
fce86ff5 DW |
1114 | unsigned long addr = vmf->address & PMD_MASK; |
1115 | struct vm_area_struct *vma = vmf->vma; | |
7b806d22 | 1116 | pgprot_t pgprot = vma->vm_page_prot; |
3b6521f5 | 1117 | pgtable_t pgtable = NULL; |
fce86ff5 | 1118 | |
5cad465d MW |
1119 | /* |
1120 | * If we had pmd_special, we could avoid all these restrictions, | |
1121 | * but we need to be consistent with PTEs and architectures that | |
1122 | * can't support a 'special' bit. | |
1123 | */ | |
e1fb4a08 DJ |
1124 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
1125 | !pfn_t_devmap(pfn)); | |
5cad465d MW |
1126 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
1127 | (VM_PFNMAP|VM_MIXEDMAP)); | |
1128 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); | |
5cad465d MW |
1129 | |
1130 | if (addr < vma->vm_start || addr >= vma->vm_end) | |
1131 | return VM_FAULT_SIGBUS; | |
308a047c | 1132 | |
3b6521f5 | 1133 | if (arch_needs_pgtable_deposit()) { |
4cf58924 | 1134 | pgtable = pte_alloc_one(vma->vm_mm); |
3b6521f5 OH |
1135 | if (!pgtable) |
1136 | return VM_FAULT_OOM; | |
1137 | } | |
1138 | ||
308a047c BP |
1139 | track_pfn_insert(vma, &pgprot, pfn); |
1140 | ||
fce86ff5 | 1141 | insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable); |
ae18d6dc | 1142 | return VM_FAULT_NOPAGE; |
5cad465d | 1143 | } |
7b806d22 | 1144 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); |
5cad465d | 1145 | |
a00cc7d9 | 1146 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
f55e1014 | 1147 | static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma) |
a00cc7d9 | 1148 | { |
f55e1014 | 1149 | if (likely(vma->vm_flags & VM_WRITE)) |
a00cc7d9 MW |
1150 | pud = pud_mkwrite(pud); |
1151 | return pud; | |
1152 | } | |
1153 | ||
1154 | static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, | |
7b806d22 | 1155 | pud_t *pud, pfn_t pfn, bool write) |
a00cc7d9 MW |
1156 | { |
1157 | struct mm_struct *mm = vma->vm_mm; | |
7b806d22 | 1158 | pgprot_t prot = vma->vm_page_prot; |
a00cc7d9 MW |
1159 | pud_t entry; |
1160 | spinlock_t *ptl; | |
1161 | ||
1162 | ptl = pud_lock(mm, pud); | |
c6f3c5ee AK |
1163 | if (!pud_none(*pud)) { |
1164 | if (write) { | |
1165 | if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { | |
1166 | WARN_ON_ONCE(!is_huge_zero_pud(*pud)); | |
1167 | goto out_unlock; | |
1168 | } | |
1169 | entry = pud_mkyoung(*pud); | |
1170 | entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); | |
1171 | if (pudp_set_access_flags(vma, addr, pud, entry, 1)) | |
1172 | update_mmu_cache_pud(vma, addr, pud); | |
1173 | } | |
1174 | goto out_unlock; | |
1175 | } | |
1176 | ||
a00cc7d9 MW |
1177 | entry = pud_mkhuge(pfn_t_pud(pfn, prot)); |
1178 | if (pfn_t_devmap(pfn)) | |
1179 | entry = pud_mkdevmap(entry); | |
1180 | if (write) { | |
f55e1014 LT |
1181 | entry = pud_mkyoung(pud_mkdirty(entry)); |
1182 | entry = maybe_pud_mkwrite(entry, vma); | |
a00cc7d9 MW |
1183 | } |
1184 | set_pud_at(mm, addr, pud, entry); | |
1185 | update_mmu_cache_pud(vma, addr, pud); | |
c6f3c5ee AK |
1186 | |
1187 | out_unlock: | |
a00cc7d9 MW |
1188 | spin_unlock(ptl); |
1189 | } | |
1190 | ||
9a9731b1 | 1191 | /** |
7b806d22 | 1192 | * vmf_insert_pfn_pud - insert a pud size pfn |
9a9731b1 THV |
1193 | * @vmf: Structure describing the fault |
1194 | * @pfn: pfn to insert | |
9a9731b1 THV |
1195 | * @write: whether it's a write fault |
1196 | * | |
7b806d22 | 1197 | * Insert a pud size pfn. See vmf_insert_pfn() for additional info. |
9a9731b1 THV |
1198 | * |
1199 | * Return: vm_fault_t value. | |
1200 | */ | |
7b806d22 | 1201 | vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write) |
a00cc7d9 | 1202 | { |
fce86ff5 DW |
1203 | unsigned long addr = vmf->address & PUD_MASK; |
1204 | struct vm_area_struct *vma = vmf->vma; | |
7b806d22 | 1205 | pgprot_t pgprot = vma->vm_page_prot; |
fce86ff5 | 1206 | |
a00cc7d9 MW |
1207 | /* |
1208 | * If we had pud_special, we could avoid all these restrictions, | |
1209 | * but we need to be consistent with PTEs and architectures that | |
1210 | * can't support a 'special' bit. | |
1211 | */ | |
62ec0d8c DJ |
1212 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
1213 | !pfn_t_devmap(pfn)); | |
a00cc7d9 MW |
1214 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
1215 | (VM_PFNMAP|VM_MIXEDMAP)); | |
1216 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); | |
a00cc7d9 MW |
1217 | |
1218 | if (addr < vma->vm_start || addr >= vma->vm_end) | |
1219 | return VM_FAULT_SIGBUS; | |
1220 | ||
1221 | track_pfn_insert(vma, &pgprot, pfn); | |
1222 | ||
7b806d22 | 1223 | insert_pfn_pud(vma, addr, vmf->pud, pfn, write); |
a00cc7d9 MW |
1224 | return VM_FAULT_NOPAGE; |
1225 | } | |
7b806d22 | 1226 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); |
a00cc7d9 MW |
1227 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
1228 | ||
3565fce3 | 1229 | static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, |
a69e4717 | 1230 | pmd_t *pmd, bool write) |
3565fce3 DW |
1231 | { |
1232 | pmd_t _pmd; | |
1233 | ||
a8f97366 | 1234 | _pmd = pmd_mkyoung(*pmd); |
a69e4717 | 1235 | if (write) |
a8f97366 | 1236 | _pmd = pmd_mkdirty(_pmd); |
3565fce3 | 1237 | if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK, |
a69e4717 | 1238 | pmd, _pmd, write)) |
3565fce3 DW |
1239 | update_mmu_cache_pmd(vma, addr, pmd); |
1240 | } | |
1241 | ||
1242 | struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, | |
df06b37f | 1243 | pmd_t *pmd, int flags, struct dev_pagemap **pgmap) |
3565fce3 DW |
1244 | { |
1245 | unsigned long pfn = pmd_pfn(*pmd); | |
1246 | struct mm_struct *mm = vma->vm_mm; | |
3565fce3 | 1247 | struct page *page; |
0f089235 | 1248 | int ret; |
3565fce3 DW |
1249 | |
1250 | assert_spin_locked(pmd_lockptr(mm, pmd)); | |
1251 | ||
f6f37321 | 1252 | if (flags & FOLL_WRITE && !pmd_write(*pmd)) |
3565fce3 DW |
1253 | return NULL; |
1254 | ||
1255 | if (pmd_present(*pmd) && pmd_devmap(*pmd)) | |
1256 | /* pass */; | |
1257 | else | |
1258 | return NULL; | |
1259 | ||
1260 | if (flags & FOLL_TOUCH) | |
a69e4717 | 1261 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
3565fce3 DW |
1262 | |
1263 | /* | |
1264 | * device mapped pages can only be returned if the | |
1265 | * caller will manage the page reference count. | |
1266 | */ | |
3faa52c0 | 1267 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
3565fce3 DW |
1268 | return ERR_PTR(-EEXIST); |
1269 | ||
1270 | pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT; | |
df06b37f KB |
1271 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
1272 | if (!*pgmap) | |
3565fce3 DW |
1273 | return ERR_PTR(-EFAULT); |
1274 | page = pfn_to_page(pfn); | |
0f089235 LG |
1275 | ret = try_grab_page(page, flags); |
1276 | if (ret) | |
1277 | page = ERR_PTR(ret); | |
3565fce3 DW |
1278 | |
1279 | return page; | |
1280 | } | |
1281 | ||
71e3aac0 AA |
1282 | int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
1283 | pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, | |
8f34f1ea | 1284 | struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) |
71e3aac0 | 1285 | { |
c4088ebd | 1286 | spinlock_t *dst_ptl, *src_ptl; |
71e3aac0 | 1287 | struct page *src_page; |
96c772c2 | 1288 | struct folio *src_folio; |
71e3aac0 | 1289 | pmd_t pmd; |
12c9d70b | 1290 | pgtable_t pgtable = NULL; |
628d47ce | 1291 | int ret = -ENOMEM; |
71e3aac0 | 1292 | |
628d47ce | 1293 | /* Skip if can be re-fill on fault */ |
8f34f1ea | 1294 | if (!vma_is_anonymous(dst_vma)) |
628d47ce KS |
1295 | return 0; |
1296 | ||
4cf58924 | 1297 | pgtable = pte_alloc_one(dst_mm); |
628d47ce KS |
1298 | if (unlikely(!pgtable)) |
1299 | goto out; | |
71e3aac0 | 1300 | |
c4088ebd KS |
1301 | dst_ptl = pmd_lock(dst_mm, dst_pmd); |
1302 | src_ptl = pmd_lockptr(src_mm, src_pmd); | |
1303 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
71e3aac0 AA |
1304 | |
1305 | ret = -EAGAIN; | |
1306 | pmd = *src_pmd; | |
84c3fc4e ZY |
1307 | |
1308 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
1309 | if (unlikely(is_swap_pmd(pmd))) { | |
1310 | swp_entry_t entry = pmd_to_swp_entry(pmd); | |
1311 | ||
1312 | VM_BUG_ON(!is_pmd_migration_entry(pmd)); | |
6c287605 | 1313 | if (!is_readable_migration_entry(entry)) { |
4dd845b5 AP |
1314 | entry = make_readable_migration_entry( |
1315 | swp_offset(entry)); | |
84c3fc4e | 1316 | pmd = swp_entry_to_pmd(entry); |
ab6e3d09 NH |
1317 | if (pmd_swp_soft_dirty(*src_pmd)) |
1318 | pmd = pmd_swp_mksoft_dirty(pmd); | |
8f34f1ea PX |
1319 | if (pmd_swp_uffd_wp(*src_pmd)) |
1320 | pmd = pmd_swp_mkuffd_wp(pmd); | |
84c3fc4e ZY |
1321 | set_pmd_at(src_mm, addr, src_pmd, pmd); |
1322 | } | |
dd8a67f9 | 1323 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
af5b0f6a | 1324 | mm_inc_nr_ptes(dst_mm); |
dd8a67f9 | 1325 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
8f34f1ea PX |
1326 | if (!userfaultfd_wp(dst_vma)) |
1327 | pmd = pmd_swp_clear_uffd_wp(pmd); | |
84c3fc4e ZY |
1328 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); |
1329 | ret = 0; | |
1330 | goto out_unlock; | |
1331 | } | |
1332 | #endif | |
1333 | ||
628d47ce | 1334 | if (unlikely(!pmd_trans_huge(pmd))) { |
71e3aac0 AA |
1335 | pte_free(dst_mm, pgtable); |
1336 | goto out_unlock; | |
1337 | } | |
fc9fe822 | 1338 | /* |
c4088ebd | 1339 | * When page table lock is held, the huge zero pmd should not be |
fc9fe822 KS |
1340 | * under splitting since we don't split the page itself, only pmd to |
1341 | * a page table. | |
1342 | */ | |
1343 | if (is_huge_zero_pmd(pmd)) { | |
97ae1749 KS |
1344 | /* |
1345 | * get_huge_zero_page() will never allocate a new page here, | |
1346 | * since we already have a zero page to copy. It just takes a | |
1347 | * reference. | |
1348 | */ | |
5fc7a5f6 PX |
1349 | mm_get_huge_zero_page(dst_mm); |
1350 | goto out_zero_page; | |
fc9fe822 | 1351 | } |
de466bd6 | 1352 | |
628d47ce KS |
1353 | src_page = pmd_page(pmd); |
1354 | VM_BUG_ON_PAGE(!PageHead(src_page), src_page); | |
96c772c2 | 1355 | src_folio = page_folio(src_page); |
d042035e | 1356 | |
96c772c2 DH |
1357 | folio_get(src_folio); |
1358 | if (unlikely(folio_try_dup_anon_rmap_pmd(src_folio, src_page, src_vma))) { | |
fb3d824d | 1359 | /* Page maybe pinned: split and retry the fault on PTEs. */ |
96c772c2 | 1360 | folio_put(src_folio); |
d042035e PX |
1361 | pte_free(dst_mm, pgtable); |
1362 | spin_unlock(src_ptl); | |
1363 | spin_unlock(dst_ptl); | |
8f34f1ea | 1364 | __split_huge_pmd(src_vma, src_pmd, addr, false, NULL); |
d042035e PX |
1365 | return -EAGAIN; |
1366 | } | |
628d47ce | 1367 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
5fc7a5f6 | 1368 | out_zero_page: |
c4812909 | 1369 | mm_inc_nr_ptes(dst_mm); |
628d47ce | 1370 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
71e3aac0 | 1371 | pmdp_set_wrprotect(src_mm, addr, src_pmd); |
8f34f1ea PX |
1372 | if (!userfaultfd_wp(dst_vma)) |
1373 | pmd = pmd_clear_uffd_wp(pmd); | |
71e3aac0 AA |
1374 | pmd = pmd_mkold(pmd_wrprotect(pmd)); |
1375 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); | |
71e3aac0 AA |
1376 | |
1377 | ret = 0; | |
1378 | out_unlock: | |
c4088ebd KS |
1379 | spin_unlock(src_ptl); |
1380 | spin_unlock(dst_ptl); | |
71e3aac0 AA |
1381 | out: |
1382 | return ret; | |
1383 | } | |
1384 | ||
a00cc7d9 MW |
1385 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
1386 | static void touch_pud(struct vm_area_struct *vma, unsigned long addr, | |
5fe653e9 | 1387 | pud_t *pud, bool write) |
a00cc7d9 MW |
1388 | { |
1389 | pud_t _pud; | |
1390 | ||
a8f97366 | 1391 | _pud = pud_mkyoung(*pud); |
5fe653e9 | 1392 | if (write) |
a8f97366 | 1393 | _pud = pud_mkdirty(_pud); |
a00cc7d9 | 1394 | if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK, |
5fe653e9 | 1395 | pud, _pud, write)) |
a00cc7d9 MW |
1396 | update_mmu_cache_pud(vma, addr, pud); |
1397 | } | |
1398 | ||
1399 | struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, | |
df06b37f | 1400 | pud_t *pud, int flags, struct dev_pagemap **pgmap) |
a00cc7d9 MW |
1401 | { |
1402 | unsigned long pfn = pud_pfn(*pud); | |
1403 | struct mm_struct *mm = vma->vm_mm; | |
a00cc7d9 | 1404 | struct page *page; |
0f089235 | 1405 | int ret; |
a00cc7d9 MW |
1406 | |
1407 | assert_spin_locked(pud_lockptr(mm, pud)); | |
1408 | ||
f6f37321 | 1409 | if (flags & FOLL_WRITE && !pud_write(*pud)) |
a00cc7d9 MW |
1410 | return NULL; |
1411 | ||
1412 | if (pud_present(*pud) && pud_devmap(*pud)) | |
1413 | /* pass */; | |
1414 | else | |
1415 | return NULL; | |
1416 | ||
1417 | if (flags & FOLL_TOUCH) | |
5fe653e9 | 1418 | touch_pud(vma, addr, pud, flags & FOLL_WRITE); |
a00cc7d9 MW |
1419 | |
1420 | /* | |
1421 | * device mapped pages can only be returned if the | |
1422 | * caller will manage the page reference count. | |
3faa52c0 JH |
1423 | * |
1424 | * At least one of FOLL_GET | FOLL_PIN must be set, so assert that here: | |
a00cc7d9 | 1425 | */ |
3faa52c0 | 1426 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
a00cc7d9 MW |
1427 | return ERR_PTR(-EEXIST); |
1428 | ||
1429 | pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT; | |
df06b37f KB |
1430 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
1431 | if (!*pgmap) | |
a00cc7d9 MW |
1432 | return ERR_PTR(-EFAULT); |
1433 | page = pfn_to_page(pfn); | |
0f089235 LG |
1434 | |
1435 | ret = try_grab_page(page, flags); | |
1436 | if (ret) | |
1437 | page = ERR_PTR(ret); | |
a00cc7d9 MW |
1438 | |
1439 | return page; | |
1440 | } | |
1441 | ||
1442 | int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
1443 | pud_t *dst_pud, pud_t *src_pud, unsigned long addr, | |
1444 | struct vm_area_struct *vma) | |
1445 | { | |
1446 | spinlock_t *dst_ptl, *src_ptl; | |
1447 | pud_t pud; | |
1448 | int ret; | |
1449 | ||
1450 | dst_ptl = pud_lock(dst_mm, dst_pud); | |
1451 | src_ptl = pud_lockptr(src_mm, src_pud); | |
1452 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
1453 | ||
1454 | ret = -EAGAIN; | |
1455 | pud = *src_pud; | |
1456 | if (unlikely(!pud_trans_huge(pud) && !pud_devmap(pud))) | |
1457 | goto out_unlock; | |
1458 | ||
1459 | /* | |
1460 | * When page table lock is held, the huge zero pud should not be | |
1461 | * under splitting since we don't split the page itself, only pud to | |
1462 | * a page table. | |
1463 | */ | |
1464 | if (is_huge_zero_pud(pud)) { | |
1465 | /* No huge zero pud yet */ | |
1466 | } | |
1467 | ||
fb3d824d | 1468 | /* |
96c772c2 DH |
1469 | * TODO: once we support anonymous pages, use |
1470 | * folio_try_dup_anon_rmap_*() and split if duplicating fails. | |
fb3d824d | 1471 | */ |
a00cc7d9 MW |
1472 | pudp_set_wrprotect(src_mm, addr, src_pud); |
1473 | pud = pud_mkold(pud_wrprotect(pud)); | |
1474 | set_pud_at(dst_mm, addr, dst_pud, pud); | |
1475 | ||
1476 | ret = 0; | |
1477 | out_unlock: | |
1478 | spin_unlock(src_ptl); | |
1479 | spin_unlock(dst_ptl); | |
1480 | return ret; | |
1481 | } | |
1482 | ||
1483 | void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) | |
1484 | { | |
a00cc7d9 MW |
1485 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
1486 | ||
1487 | vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud); | |
1488 | if (unlikely(!pud_same(*vmf->pud, orig_pud))) | |
1489 | goto unlock; | |
1490 | ||
5fe653e9 | 1491 | touch_pud(vmf->vma, vmf->address, vmf->pud, write); |
a00cc7d9 MW |
1492 | unlock: |
1493 | spin_unlock(vmf->ptl); | |
1494 | } | |
1495 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ | |
1496 | ||
5db4f15c | 1497 | void huge_pmd_set_accessed(struct vm_fault *vmf) |
a1dd450b | 1498 | { |
20f664aa | 1499 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
a1dd450b | 1500 | |
82b0f8c3 | 1501 | vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); |
a69e4717 | 1502 | if (unlikely(!pmd_same(*vmf->pmd, vmf->orig_pmd))) |
a1dd450b WD |
1503 | goto unlock; |
1504 | ||
a69e4717 | 1505 | touch_pmd(vmf->vma, vmf->address, vmf->pmd, write); |
a1dd450b WD |
1506 | |
1507 | unlock: | |
82b0f8c3 | 1508 | spin_unlock(vmf->ptl); |
a1dd450b WD |
1509 | } |
1510 | ||
5db4f15c | 1511 | vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) |
71e3aac0 | 1512 | { |
c89357e2 | 1513 | const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; |
82b0f8c3 | 1514 | struct vm_area_struct *vma = vmf->vma; |
2fad3d14 | 1515 | struct folio *folio; |
3917c802 | 1516 | struct page *page; |
82b0f8c3 | 1517 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
5db4f15c | 1518 | pmd_t orig_pmd = vmf->orig_pmd; |
71e3aac0 | 1519 | |
82b0f8c3 | 1520 | vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd); |
81d1b09c | 1521 | VM_BUG_ON_VMA(!vma->anon_vma, vma); |
3917c802 | 1522 | |
93b4796d | 1523 | if (is_huge_zero_pmd(orig_pmd)) |
3917c802 KS |
1524 | goto fallback; |
1525 | ||
82b0f8c3 | 1526 | spin_lock(vmf->ptl); |
3917c802 KS |
1527 | |
1528 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { | |
1529 | spin_unlock(vmf->ptl); | |
1530 | return 0; | |
1531 | } | |
71e3aac0 AA |
1532 | |
1533 | page = pmd_page(orig_pmd); | |
2fad3d14 | 1534 | folio = page_folio(page); |
f6004e73 | 1535 | VM_BUG_ON_PAGE(!PageHead(page), page); |
3917c802 | 1536 | |
6c287605 DH |
1537 | /* Early check when only holding the PT lock. */ |
1538 | if (PageAnonExclusive(page)) | |
1539 | goto reuse; | |
1540 | ||
2fad3d14 MWO |
1541 | if (!folio_trylock(folio)) { |
1542 | folio_get(folio); | |
ba3c4ce6 | 1543 | spin_unlock(vmf->ptl); |
2fad3d14 | 1544 | folio_lock(folio); |
ba3c4ce6 HY |
1545 | spin_lock(vmf->ptl); |
1546 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { | |
3917c802 | 1547 | spin_unlock(vmf->ptl); |
2fad3d14 MWO |
1548 | folio_unlock(folio); |
1549 | folio_put(folio); | |
3917c802 | 1550 | return 0; |
ba3c4ce6 | 1551 | } |
2fad3d14 | 1552 | folio_put(folio); |
ba3c4ce6 | 1553 | } |
3917c802 | 1554 | |
6c287605 DH |
1555 | /* Recheck after temporarily dropping the PT lock. */ |
1556 | if (PageAnonExclusive(page)) { | |
2fad3d14 | 1557 | folio_unlock(folio); |
6c287605 DH |
1558 | goto reuse; |
1559 | } | |
1560 | ||
3917c802 | 1561 | /* |
2fad3d14 MWO |
1562 | * See do_wp_page(): we can only reuse the folio exclusively if |
1563 | * there are no additional references. Note that we always drain | |
1fec6890 | 1564 | * the LRU cache immediately after adding a THP. |
3917c802 | 1565 | */ |
2fad3d14 MWO |
1566 | if (folio_ref_count(folio) > |
1567 | 1 + folio_test_swapcache(folio) * folio_nr_pages(folio)) | |
3bff7e3f | 1568 | goto unlock_fallback; |
2fad3d14 MWO |
1569 | if (folio_test_swapcache(folio)) |
1570 | folio_free_swap(folio); | |
1571 | if (folio_ref_count(folio) == 1) { | |
71e3aac0 | 1572 | pmd_t entry; |
6c54dc6c | 1573 | |
06968625 | 1574 | folio_move_anon_rmap(folio, vma); |
5ca43289 | 1575 | SetPageAnonExclusive(page); |
2fad3d14 | 1576 | folio_unlock(folio); |
6c287605 | 1577 | reuse: |
c89357e2 DH |
1578 | if (unlikely(unshare)) { |
1579 | spin_unlock(vmf->ptl); | |
1580 | return 0; | |
1581 | } | |
71e3aac0 | 1582 | entry = pmd_mkyoung(orig_pmd); |
f55e1014 | 1583 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
3917c802 | 1584 | if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1)) |
82b0f8c3 | 1585 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
82b0f8c3 | 1586 | spin_unlock(vmf->ptl); |
cb8d8633 | 1587 | return 0; |
71e3aac0 | 1588 | } |
3917c802 | 1589 | |
3bff7e3f | 1590 | unlock_fallback: |
2fad3d14 | 1591 | folio_unlock(folio); |
82b0f8c3 | 1592 | spin_unlock(vmf->ptl); |
3917c802 KS |
1593 | fallback: |
1594 | __split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL); | |
1595 | return VM_FAULT_FALLBACK; | |
71e3aac0 AA |
1596 | } |
1597 | ||
c27f479e DH |
1598 | static inline bool can_change_pmd_writable(struct vm_area_struct *vma, |
1599 | unsigned long addr, pmd_t pmd) | |
1600 | { | |
1601 | struct page *page; | |
1602 | ||
1603 | if (WARN_ON_ONCE(!(vma->vm_flags & VM_WRITE))) | |
1604 | return false; | |
1605 | ||
1606 | /* Don't touch entries that are not even readable (NUMA hinting). */ | |
1607 | if (pmd_protnone(pmd)) | |
1608 | return false; | |
1609 | ||
1610 | /* Do we need write faults for softdirty tracking? */ | |
1611 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) | |
1612 | return false; | |
1613 | ||
1614 | /* Do we need write faults for uffd-wp tracking? */ | |
1615 | if (userfaultfd_huge_pmd_wp(vma, pmd)) | |
1616 | return false; | |
1617 | ||
1618 | if (!(vma->vm_flags & VM_SHARED)) { | |
1619 | /* See can_change_pte_writable(). */ | |
1620 | page = vm_normal_page_pmd(vma, addr, pmd); | |
1621 | return page && PageAnon(page) && PageAnonExclusive(page); | |
1622 | } | |
1623 | ||
1624 | /* See can_change_pte_writable(). */ | |
1625 | return pmd_dirty(pmd); | |
1626 | } | |
1627 | ||
5535be30 DH |
1628 | /* FOLL_FORCE can write to even unwritable PMDs in COW mappings. */ |
1629 | static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, | |
1630 | struct vm_area_struct *vma, | |
1631 | unsigned int flags) | |
8310d48b | 1632 | { |
5535be30 DH |
1633 | /* If the pmd is writable, we can write to the page. */ |
1634 | if (pmd_write(pmd)) | |
1635 | return true; | |
1636 | ||
1637 | /* Maybe FOLL_FORCE is set to override it? */ | |
1638 | if (!(flags & FOLL_FORCE)) | |
1639 | return false; | |
1640 | ||
1641 | /* But FOLL_FORCE has no effect on shared mappings */ | |
1642 | if (vma->vm_flags & (VM_MAYSHARE | VM_SHARED)) | |
1643 | return false; | |
1644 | ||
1645 | /* ... or read-only private ones */ | |
1646 | if (!(vma->vm_flags & VM_MAYWRITE)) | |
1647 | return false; | |
1648 | ||
1649 | /* ... or already writable ones that just need to take a write fault */ | |
1650 | if (vma->vm_flags & VM_WRITE) | |
1651 | return false; | |
1652 | ||
1653 | /* | |
1654 | * See can_change_pte_writable(): we broke COW and could map the page | |
1655 | * writable if we have an exclusive anonymous page ... | |
1656 | */ | |
1657 | if (!page || !PageAnon(page) || !PageAnonExclusive(page)) | |
1658 | return false; | |
1659 | ||
1660 | /* ... and a write-fault isn't required for other reasons. */ | |
1661 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) | |
1662 | return false; | |
1663 | return !userfaultfd_huge_pmd_wp(vma, pmd); | |
8310d48b KF |
1664 | } |
1665 | ||
b676b293 | 1666 | struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, |
71e3aac0 AA |
1667 | unsigned long addr, |
1668 | pmd_t *pmd, | |
1669 | unsigned int flags) | |
1670 | { | |
b676b293 | 1671 | struct mm_struct *mm = vma->vm_mm; |
5535be30 | 1672 | struct page *page; |
0f089235 | 1673 | int ret; |
71e3aac0 | 1674 | |
c4088ebd | 1675 | assert_spin_locked(pmd_lockptr(mm, pmd)); |
71e3aac0 | 1676 | |
5535be30 DH |
1677 | page = pmd_page(*pmd); |
1678 | VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); | |
1679 | ||
1680 | if ((flags & FOLL_WRITE) && | |
1681 | !can_follow_write_pmd(*pmd, page, vma, flags)) | |
1682 | return NULL; | |
71e3aac0 | 1683 | |
85facf25 KS |
1684 | /* Avoid dumping huge zero page */ |
1685 | if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd)) | |
1686 | return ERR_PTR(-EFAULT); | |
1687 | ||
d74943a2 | 1688 | if (pmd_protnone(*pmd) && !gup_can_follow_protnone(vma, flags)) |
5535be30 | 1689 | return NULL; |
3faa52c0 | 1690 | |
84209e87 | 1691 | if (!pmd_write(*pmd) && gup_must_unshare(vma, flags, page)) |
a7f22660 DH |
1692 | return ERR_PTR(-EMLINK); |
1693 | ||
b6a2619c DH |
1694 | VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && |
1695 | !PageAnonExclusive(page), page); | |
1696 | ||
0f089235 LG |
1697 | ret = try_grab_page(page, flags); |
1698 | if (ret) | |
1699 | return ERR_PTR(ret); | |
3faa52c0 | 1700 | |
3565fce3 | 1701 | if (flags & FOLL_TOUCH) |
a69e4717 | 1702 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
3faa52c0 | 1703 | |
71e3aac0 | 1704 | page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; |
ca120cf6 | 1705 | VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); |
71e3aac0 | 1706 | |
71e3aac0 AA |
1707 | return page; |
1708 | } | |
1709 | ||
d10e63f2 | 1710 | /* NUMA hinting page fault entry point for trans huge pmds */ |
5db4f15c | 1711 | vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) |
d10e63f2 | 1712 | { |
82b0f8c3 | 1713 | struct vm_area_struct *vma = vmf->vma; |
c5b5a3dd YS |
1714 | pmd_t oldpmd = vmf->orig_pmd; |
1715 | pmd_t pmd; | |
667ffc31 | 1716 | struct folio *folio; |
82b0f8c3 | 1717 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
667ffc31 | 1718 | int nid = NUMA_NO_NODE; |
33024536 | 1719 | int target_nid, last_cpupid = (-1 & LAST_CPUPID_MASK); |
6a56ccbc | 1720 | bool migrated = false, writable = false; |
6688cc05 | 1721 | int flags = 0; |
d10e63f2 | 1722 | |
82b0f8c3 | 1723 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
c5b5a3dd | 1724 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { |
82b0f8c3 | 1725 | spin_unlock(vmf->ptl); |
de466bd6 MG |
1726 | goto out; |
1727 | } | |
1728 | ||
c5b5a3dd | 1729 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); |
6a56ccbc DH |
1730 | |
1731 | /* | |
1732 | * Detect now whether the PMD could be writable; this information | |
1733 | * is only valid while holding the PT lock. | |
1734 | */ | |
1735 | writable = pmd_write(pmd); | |
1736 | if (!writable && vma_wants_manual_pte_write_upgrade(vma) && | |
1737 | can_change_pmd_writable(vma, vmf->address, pmd)) | |
1738 | writable = true; | |
1739 | ||
667ffc31 KW |
1740 | folio = vm_normal_folio_pmd(vma, haddr, pmd); |
1741 | if (!folio) | |
c5b5a3dd YS |
1742 | goto out_map; |
1743 | ||
1744 | /* See similar comment in do_numa_page for explanation */ | |
6a56ccbc | 1745 | if (!writable) |
c5b5a3dd YS |
1746 | flags |= TNF_NO_GROUP; |
1747 | ||
667ffc31 | 1748 | nid = folio_nid(folio); |
33024536 HY |
1749 | /* |
1750 | * For memory tiering mode, cpupid of slow memory page is used | |
1751 | * to record page access time. So use default value. | |
1752 | */ | |
667ffc31 | 1753 | if (node_is_toptier(nid)) |
c4a8d2fa | 1754 | last_cpupid = folio_last_cpupid(folio); |
cda6d936 | 1755 | target_nid = numa_migrate_prep(folio, vma, haddr, nid, &flags); |
c5b5a3dd | 1756 | if (target_nid == NUMA_NO_NODE) { |
667ffc31 | 1757 | folio_put(folio); |
c5b5a3dd YS |
1758 | goto out_map; |
1759 | } | |
1760 | ||
82b0f8c3 | 1761 | spin_unlock(vmf->ptl); |
6a56ccbc | 1762 | writable = false; |
8b1b436d | 1763 | |
667ffc31 | 1764 | migrated = migrate_misplaced_folio(folio, vma, target_nid); |
6688cc05 PZ |
1765 | if (migrated) { |
1766 | flags |= TNF_MIGRATED; | |
667ffc31 | 1767 | nid = target_nid; |
c5b5a3dd | 1768 | } else { |
074c2381 | 1769 | flags |= TNF_MIGRATE_FAIL; |
c5b5a3dd YS |
1770 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
1771 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { | |
1772 | spin_unlock(vmf->ptl); | |
1773 | goto out; | |
1774 | } | |
1775 | goto out_map; | |
1776 | } | |
b8916634 MG |
1777 | |
1778 | out: | |
667ffc31 KW |
1779 | if (nid != NUMA_NO_NODE) |
1780 | task_numa_fault(last_cpupid, nid, HPAGE_PMD_NR, flags); | |
8191acbd | 1781 | |
d10e63f2 | 1782 | return 0; |
c5b5a3dd YS |
1783 | |
1784 | out_map: | |
1785 | /* Restore the PMD */ | |
1786 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); | |
1787 | pmd = pmd_mkyoung(pmd); | |
6a56ccbc | 1788 | if (writable) |
161e393c | 1789 | pmd = pmd_mkwrite(pmd, vma); |
c5b5a3dd YS |
1790 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd); |
1791 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); | |
1792 | spin_unlock(vmf->ptl); | |
1793 | goto out; | |
d10e63f2 MG |
1794 | } |
1795 | ||
319904ad HY |
1796 | /* |
1797 | * Return true if we do MADV_FREE successfully on entire pmd page. | |
1798 | * Otherwise, return false. | |
1799 | */ | |
1800 | bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
b8d3c4c3 | 1801 | pmd_t *pmd, unsigned long addr, unsigned long next) |
b8d3c4c3 MK |
1802 | { |
1803 | spinlock_t *ptl; | |
1804 | pmd_t orig_pmd; | |
fc986a38 | 1805 | struct folio *folio; |
b8d3c4c3 | 1806 | struct mm_struct *mm = tlb->mm; |
319904ad | 1807 | bool ret = false; |
b8d3c4c3 | 1808 | |
ed6a7935 | 1809 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
07e32661 | 1810 | |
b6ec57f4 KS |
1811 | ptl = pmd_trans_huge_lock(pmd, vma); |
1812 | if (!ptl) | |
25eedabe | 1813 | goto out_unlocked; |
b8d3c4c3 MK |
1814 | |
1815 | orig_pmd = *pmd; | |
319904ad | 1816 | if (is_huge_zero_pmd(orig_pmd)) |
b8d3c4c3 | 1817 | goto out; |
b8d3c4c3 | 1818 | |
84c3fc4e ZY |
1819 | if (unlikely(!pmd_present(orig_pmd))) { |
1820 | VM_BUG_ON(thp_migration_supported() && | |
1821 | !is_pmd_migration_entry(orig_pmd)); | |
1822 | goto out; | |
1823 | } | |
1824 | ||
fc986a38 | 1825 | folio = pfn_folio(pmd_pfn(orig_pmd)); |
b8d3c4c3 | 1826 | /* |
fc986a38 KW |
1827 | * If other processes are mapping this folio, we couldn't discard |
1828 | * the folio unless they all do MADV_FREE so let's skip the folio. | |
b8d3c4c3 | 1829 | */ |
20b18aad | 1830 | if (folio_estimated_sharers(folio) != 1) |
b8d3c4c3 MK |
1831 | goto out; |
1832 | ||
fc986a38 | 1833 | if (!folio_trylock(folio)) |
b8d3c4c3 MK |
1834 | goto out; |
1835 | ||
1836 | /* | |
1837 | * If user want to discard part-pages of THP, split it so MADV_FREE | |
1838 | * will deactivate only them. | |
1839 | */ | |
1840 | if (next - addr != HPAGE_PMD_SIZE) { | |
fc986a38 | 1841 | folio_get(folio); |
b8d3c4c3 | 1842 | spin_unlock(ptl); |
fc986a38 KW |
1843 | split_folio(folio); |
1844 | folio_unlock(folio); | |
1845 | folio_put(folio); | |
b8d3c4c3 MK |
1846 | goto out_unlocked; |
1847 | } | |
1848 | ||
fc986a38 KW |
1849 | if (folio_test_dirty(folio)) |
1850 | folio_clear_dirty(folio); | |
1851 | folio_unlock(folio); | |
b8d3c4c3 | 1852 | |
b8d3c4c3 | 1853 | if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) { |
58ceeb6b | 1854 | pmdp_invalidate(vma, addr, pmd); |
b8d3c4c3 MK |
1855 | orig_pmd = pmd_mkold(orig_pmd); |
1856 | orig_pmd = pmd_mkclean(orig_pmd); | |
1857 | ||
1858 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
1859 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
1860 | } | |
802a3a92 | 1861 | |
6a6fe9eb | 1862 | folio_mark_lazyfree(folio); |
319904ad | 1863 | ret = true; |
b8d3c4c3 MK |
1864 | out: |
1865 | spin_unlock(ptl); | |
1866 | out_unlocked: | |
1867 | return ret; | |
1868 | } | |
1869 | ||
953c66c2 AK |
1870 | static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) |
1871 | { | |
1872 | pgtable_t pgtable; | |
1873 | ||
1874 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); | |
1875 | pte_free(mm, pgtable); | |
c4812909 | 1876 | mm_dec_nr_ptes(mm); |
953c66c2 AK |
1877 | } |
1878 | ||
71e3aac0 | 1879 | int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
f21760b1 | 1880 | pmd_t *pmd, unsigned long addr) |
71e3aac0 | 1881 | { |
da146769 | 1882 | pmd_t orig_pmd; |
bf929152 | 1883 | spinlock_t *ptl; |
71e3aac0 | 1884 | |
ed6a7935 | 1885 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
07e32661 | 1886 | |
b6ec57f4 KS |
1887 | ptl = __pmd_trans_huge_lock(pmd, vma); |
1888 | if (!ptl) | |
da146769 KS |
1889 | return 0; |
1890 | /* | |
1891 | * For architectures like ppc64 we look at deposited pgtable | |
1892 | * when calling pmdp_huge_get_and_clear. So do the | |
1893 | * pgtable_trans_huge_withdraw after finishing pmdp related | |
1894 | * operations. | |
1895 | */ | |
93a98695 AK |
1896 | orig_pmd = pmdp_huge_get_and_clear_full(vma, addr, pmd, |
1897 | tlb->fullmm); | |
e5136e87 | 1898 | arch_check_zapped_pmd(vma, orig_pmd); |
da146769 | 1899 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); |
2484ca9b | 1900 | if (vma_is_special_huge(vma)) { |
3b6521f5 OH |
1901 | if (arch_needs_pgtable_deposit()) |
1902 | zap_deposited_table(tlb->mm, pmd); | |
da146769 | 1903 | spin_unlock(ptl); |
da146769 | 1904 | } else if (is_huge_zero_pmd(orig_pmd)) { |
c14a6eb4 | 1905 | zap_deposited_table(tlb->mm, pmd); |
da146769 | 1906 | spin_unlock(ptl); |
da146769 | 1907 | } else { |
616b8371 ZY |
1908 | struct page *page = NULL; |
1909 | int flush_needed = 1; | |
1910 | ||
1911 | if (pmd_present(orig_pmd)) { | |
1912 | page = pmd_page(orig_pmd); | |
a8e61d58 | 1913 | folio_remove_rmap_pmd(page_folio(page), page, vma); |
616b8371 ZY |
1914 | VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); |
1915 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
1916 | } else if (thp_migration_supported()) { | |
1917 | swp_entry_t entry; | |
1918 | ||
1919 | VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); | |
1920 | entry = pmd_to_swp_entry(orig_pmd); | |
af5cdaf8 | 1921 | page = pfn_swap_entry_to_page(entry); |
616b8371 ZY |
1922 | flush_needed = 0; |
1923 | } else | |
1924 | WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!"); | |
1925 | ||
b5072380 | 1926 | if (PageAnon(page)) { |
c14a6eb4 | 1927 | zap_deposited_table(tlb->mm, pmd); |
b5072380 KS |
1928 | add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); |
1929 | } else { | |
953c66c2 AK |
1930 | if (arch_needs_pgtable_deposit()) |
1931 | zap_deposited_table(tlb->mm, pmd); | |
fadae295 | 1932 | add_mm_counter(tlb->mm, mm_counter_file(page), -HPAGE_PMD_NR); |
b5072380 | 1933 | } |
616b8371 | 1934 | |
da146769 | 1935 | spin_unlock(ptl); |
616b8371 ZY |
1936 | if (flush_needed) |
1937 | tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE); | |
025c5b24 | 1938 | } |
da146769 | 1939 | return 1; |
71e3aac0 AA |
1940 | } |
1941 | ||
1dd38b6c AK |
1942 | #ifndef pmd_move_must_withdraw |
1943 | static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl, | |
1944 | spinlock_t *old_pmd_ptl, | |
1945 | struct vm_area_struct *vma) | |
1946 | { | |
1947 | /* | |
1948 | * With split pmd lock we also need to move preallocated | |
1949 | * PTE page table if new_pmd is on different PMD page table. | |
1950 | * | |
1951 | * We also don't deposit and withdraw tables for file pages. | |
1952 | */ | |
1953 | return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma); | |
1954 | } | |
1955 | #endif | |
1956 | ||
ab6e3d09 NH |
1957 | static pmd_t move_soft_dirty_pmd(pmd_t pmd) |
1958 | { | |
1959 | #ifdef CONFIG_MEM_SOFT_DIRTY | |
1960 | if (unlikely(is_pmd_migration_entry(pmd))) | |
1961 | pmd = pmd_swp_mksoft_dirty(pmd); | |
1962 | else if (pmd_present(pmd)) | |
1963 | pmd = pmd_mksoft_dirty(pmd); | |
1964 | #endif | |
1965 | return pmd; | |
1966 | } | |
1967 | ||
bf8616d5 | 1968 | bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, |
b8aa9d9d | 1969 | unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) |
37a1c49a | 1970 | { |
bf929152 | 1971 | spinlock_t *old_ptl, *new_ptl; |
37a1c49a | 1972 | pmd_t pmd; |
37a1c49a | 1973 | struct mm_struct *mm = vma->vm_mm; |
5d190420 | 1974 | bool force_flush = false; |
37a1c49a | 1975 | |
37a1c49a AA |
1976 | /* |
1977 | * The destination pmd shouldn't be established, free_pgtables() | |
a5be621e HD |
1978 | * should have released it; but move_page_tables() might have already |
1979 | * inserted a page table, if racing against shmem/file collapse. | |
37a1c49a | 1980 | */ |
a5be621e | 1981 | if (!pmd_none(*new_pmd)) { |
37a1c49a | 1982 | VM_BUG_ON(pmd_trans_huge(*new_pmd)); |
4b471e88 | 1983 | return false; |
37a1c49a AA |
1984 | } |
1985 | ||
bf929152 KS |
1986 | /* |
1987 | * We don't have to worry about the ordering of src and dst | |
c1e8d7c6 | 1988 | * ptlocks because exclusive mmap_lock prevents deadlock. |
bf929152 | 1989 | */ |
b6ec57f4 KS |
1990 | old_ptl = __pmd_trans_huge_lock(old_pmd, vma); |
1991 | if (old_ptl) { | |
bf929152 KS |
1992 | new_ptl = pmd_lockptr(mm, new_pmd); |
1993 | if (new_ptl != old_ptl) | |
1994 | spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); | |
8809aa2d | 1995 | pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); |
eb66ae03 | 1996 | if (pmd_present(pmd)) |
a2ce2666 | 1997 | force_flush = true; |
025c5b24 | 1998 | VM_BUG_ON(!pmd_none(*new_pmd)); |
3592806c | 1999 | |
1dd38b6c | 2000 | if (pmd_move_must_withdraw(new_ptl, old_ptl, vma)) { |
b3084f4d | 2001 | pgtable_t pgtable; |
3592806c KS |
2002 | pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); |
2003 | pgtable_trans_huge_deposit(mm, new_pmd, pgtable); | |
3592806c | 2004 | } |
ab6e3d09 NH |
2005 | pmd = move_soft_dirty_pmd(pmd); |
2006 | set_pmd_at(mm, new_addr, new_pmd, pmd); | |
5d190420 | 2007 | if (force_flush) |
7c38f181 | 2008 | flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); |
eb66ae03 LT |
2009 | if (new_ptl != old_ptl) |
2010 | spin_unlock(new_ptl); | |
bf929152 | 2011 | spin_unlock(old_ptl); |
4b471e88 | 2012 | return true; |
37a1c49a | 2013 | } |
4b471e88 | 2014 | return false; |
37a1c49a AA |
2015 | } |
2016 | ||
f123d74a MG |
2017 | /* |
2018 | * Returns | |
2019 | * - 0 if PMD could not be locked | |
f0953a1b | 2020 | * - 1 if PMD was locked but protections unchanged and TLB flush unnecessary |
e346e668 | 2021 | * or if prot_numa but THP migration is not supported |
f0953a1b | 2022 | * - HPAGE_PMD_NR if protections changed and TLB flush necessary |
f123d74a | 2023 | */ |
4a18419f NA |
2024 | int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
2025 | pmd_t *pmd, unsigned long addr, pgprot_t newprot, | |
2026 | unsigned long cp_flags) | |
cd7548ab JW |
2027 | { |
2028 | struct mm_struct *mm = vma->vm_mm; | |
bf929152 | 2029 | spinlock_t *ptl; |
c9fe6656 | 2030 | pmd_t oldpmd, entry; |
58705444 | 2031 | bool prot_numa = cp_flags & MM_CP_PROT_NUMA; |
292924b2 PX |
2032 | bool uffd_wp = cp_flags & MM_CP_UFFD_WP; |
2033 | bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; | |
6a56ccbc | 2034 | int ret = 1; |
cd7548ab | 2035 | |
4a18419f NA |
2036 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
2037 | ||
e346e668 YS |
2038 | if (prot_numa && !thp_migration_supported()) |
2039 | return 1; | |
2040 | ||
b6ec57f4 | 2041 | ptl = __pmd_trans_huge_lock(pmd, vma); |
0a85e51d KS |
2042 | if (!ptl) |
2043 | return 0; | |
e944fd67 | 2044 | |
84c3fc4e ZY |
2045 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION |
2046 | if (is_swap_pmd(*pmd)) { | |
2047 | swp_entry_t entry = pmd_to_swp_entry(*pmd); | |
d986ba2b | 2048 | struct folio *folio = page_folio(pfn_swap_entry_to_page(entry)); |
24bf08c4 | 2049 | pmd_t newpmd; |
84c3fc4e ZY |
2050 | |
2051 | VM_BUG_ON(!is_pmd_migration_entry(*pmd)); | |
4dd845b5 | 2052 | if (is_writable_migration_entry(entry)) { |
84c3fc4e ZY |
2053 | /* |
2054 | * A protection check is difficult so | |
2055 | * just be safe and disable write | |
2056 | */ | |
d986ba2b | 2057 | if (folio_test_anon(folio)) |
6c287605 DH |
2058 | entry = make_readable_exclusive_migration_entry(swp_offset(entry)); |
2059 | else | |
2060 | entry = make_readable_migration_entry(swp_offset(entry)); | |
84c3fc4e | 2061 | newpmd = swp_entry_to_pmd(entry); |
ab6e3d09 NH |
2062 | if (pmd_swp_soft_dirty(*pmd)) |
2063 | newpmd = pmd_swp_mksoft_dirty(newpmd); | |
24bf08c4 DH |
2064 | } else { |
2065 | newpmd = *pmd; | |
84c3fc4e | 2066 | } |
24bf08c4 DH |
2067 | |
2068 | if (uffd_wp) | |
2069 | newpmd = pmd_swp_mkuffd_wp(newpmd); | |
2070 | else if (uffd_wp_resolve) | |
2071 | newpmd = pmd_swp_clear_uffd_wp(newpmd); | |
2072 | if (!pmd_same(*pmd, newpmd)) | |
2073 | set_pmd_at(mm, addr, pmd, newpmd); | |
84c3fc4e ZY |
2074 | goto unlock; |
2075 | } | |
2076 | #endif | |
2077 | ||
a1a3a2fc | 2078 | if (prot_numa) { |
d986ba2b | 2079 | struct folio *folio; |
33024536 | 2080 | bool toptier; |
a1a3a2fc HY |
2081 | /* |
2082 | * Avoid trapping faults against the zero page. The read-only | |
2083 | * data is likely to be read-cached on the local CPU and | |
2084 | * local/remote hits to the zero page are not interesting. | |
2085 | */ | |
2086 | if (is_huge_zero_pmd(*pmd)) | |
2087 | goto unlock; | |
025c5b24 | 2088 | |
a1a3a2fc HY |
2089 | if (pmd_protnone(*pmd)) |
2090 | goto unlock; | |
0a85e51d | 2091 | |
d986ba2b KW |
2092 | folio = page_folio(pmd_page(*pmd)); |
2093 | toptier = node_is_toptier(folio_nid(folio)); | |
a1a3a2fc HY |
2094 | /* |
2095 | * Skip scanning top tier node if normal numa | |
2096 | * balancing is disabled | |
2097 | */ | |
2098 | if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && | |
33024536 | 2099 | toptier) |
a1a3a2fc | 2100 | goto unlock; |
33024536 HY |
2101 | |
2102 | if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING && | |
2103 | !toptier) | |
d986ba2b KW |
2104 | folio_xchg_access_time(folio, |
2105 | jiffies_to_msecs(jiffies)); | |
a1a3a2fc | 2106 | } |
ced10803 | 2107 | /* |
3e4e28c5 | 2108 | * In case prot_numa, we are under mmap_read_lock(mm). It's critical |
ced10803 | 2109 | * to not clear pmd intermittently to avoid race with MADV_DONTNEED |
3e4e28c5 | 2110 | * which is also under mmap_read_lock(mm): |
ced10803 KS |
2111 | * |
2112 | * CPU0: CPU1: | |
2113 | * change_huge_pmd(prot_numa=1) | |
2114 | * pmdp_huge_get_and_clear_notify() | |
2115 | * madvise_dontneed() | |
2116 | * zap_pmd_range() | |
2117 | * pmd_trans_huge(*pmd) == 0 (without ptl) | |
2118 | * // skip the pmd | |
2119 | * set_pmd_at(); | |
2120 | * // pmd is re-established | |
2121 | * | |
2122 | * The race makes MADV_DONTNEED miss the huge pmd and don't clear it | |
2123 | * which may break userspace. | |
2124 | * | |
4f831457 | 2125 | * pmdp_invalidate_ad() is required to make sure we don't miss |
ced10803 KS |
2126 | * dirty/young flags set by hardware. |
2127 | */ | |
4f831457 | 2128 | oldpmd = pmdp_invalidate_ad(vma, addr, pmd); |
ced10803 | 2129 | |
c9fe6656 | 2130 | entry = pmd_modify(oldpmd, newprot); |
f1eb1bac | 2131 | if (uffd_wp) |
292924b2 | 2132 | entry = pmd_mkuffd_wp(entry); |
f1eb1bac | 2133 | else if (uffd_wp_resolve) |
292924b2 PX |
2134 | /* |
2135 | * Leave the write bit to be handled by PF interrupt | |
2136 | * handler, then things like COW could be properly | |
2137 | * handled. | |
2138 | */ | |
2139 | entry = pmd_clear_uffd_wp(entry); | |
c27f479e DH |
2140 | |
2141 | /* See change_pte_range(). */ | |
2142 | if ((cp_flags & MM_CP_TRY_CHANGE_WRITABLE) && !pmd_write(entry) && | |
2143 | can_change_pmd_writable(vma, addr, entry)) | |
161e393c | 2144 | entry = pmd_mkwrite(entry, vma); |
c27f479e | 2145 | |
0a85e51d KS |
2146 | ret = HPAGE_PMD_NR; |
2147 | set_pmd_at(mm, addr, pmd, entry); | |
4a18419f | 2148 | |
c9fe6656 NA |
2149 | if (huge_pmd_needs_flush(oldpmd, entry)) |
2150 | tlb_flush_pmd_range(tlb, addr, HPAGE_PMD_SIZE); | |
0a85e51d KS |
2151 | unlock: |
2152 | spin_unlock(ptl); | |
025c5b24 NH |
2153 | return ret; |
2154 | } | |
2155 | ||
adef4406 AA |
2156 | #ifdef CONFIG_USERFAULTFD |
2157 | /* | |
2158 | * The PT lock for src_pmd and the mmap_lock for reading are held by | |
2159 | * the caller, but it must return after releasing the page_table_lock. | |
2160 | * Just move the page from src_pmd to dst_pmd if possible. | |
2161 | * Return zero if succeeded in moving the page, -EAGAIN if it needs to be | |
2162 | * repeated by the caller, or other errors in case of failure. | |
2163 | */ | |
2164 | int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pmd_t dst_pmdval, | |
2165 | struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, | |
2166 | unsigned long dst_addr, unsigned long src_addr) | |
2167 | { | |
2168 | pmd_t _dst_pmd, src_pmdval; | |
2169 | struct page *src_page; | |
2170 | struct folio *src_folio; | |
2171 | struct anon_vma *src_anon_vma; | |
2172 | spinlock_t *src_ptl, *dst_ptl; | |
2173 | pgtable_t src_pgtable; | |
2174 | struct mmu_notifier_range range; | |
2175 | int err = 0; | |
2176 | ||
2177 | src_pmdval = *src_pmd; | |
2178 | src_ptl = pmd_lockptr(mm, src_pmd); | |
2179 | ||
2180 | lockdep_assert_held(src_ptl); | |
2181 | mmap_assert_locked(mm); | |
2182 | ||
2183 | /* Sanity checks before the operation */ | |
2184 | if (WARN_ON_ONCE(!pmd_none(dst_pmdval)) || WARN_ON_ONCE(src_addr & ~HPAGE_PMD_MASK) || | |
2185 | WARN_ON_ONCE(dst_addr & ~HPAGE_PMD_MASK)) { | |
2186 | spin_unlock(src_ptl); | |
2187 | return -EINVAL; | |
2188 | } | |
2189 | ||
2190 | if (!pmd_trans_huge(src_pmdval)) { | |
2191 | spin_unlock(src_ptl); | |
2192 | if (is_pmd_migration_entry(src_pmdval)) { | |
2193 | pmd_migration_entry_wait(mm, &src_pmdval); | |
2194 | return -EAGAIN; | |
2195 | } | |
2196 | return -ENOENT; | |
2197 | } | |
2198 | ||
2199 | src_page = pmd_page(src_pmdval); | |
2200 | if (unlikely(!PageAnonExclusive(src_page))) { | |
2201 | spin_unlock(src_ptl); | |
2202 | return -EBUSY; | |
2203 | } | |
2204 | ||
2205 | src_folio = page_folio(src_page); | |
2206 | folio_get(src_folio); | |
2207 | spin_unlock(src_ptl); | |
2208 | ||
2209 | flush_cache_range(src_vma, src_addr, src_addr + HPAGE_PMD_SIZE); | |
2210 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, src_addr, | |
2211 | src_addr + HPAGE_PMD_SIZE); | |
2212 | mmu_notifier_invalidate_range_start(&range); | |
2213 | ||
2214 | folio_lock(src_folio); | |
2215 | ||
2216 | /* | |
2217 | * split_huge_page walks the anon_vma chain without the page | |
2218 | * lock. Serialize against it with the anon_vma lock, the page | |
2219 | * lock is not enough. | |
2220 | */ | |
2221 | src_anon_vma = folio_get_anon_vma(src_folio); | |
2222 | if (!src_anon_vma) { | |
2223 | err = -EAGAIN; | |
2224 | goto unlock_folio; | |
2225 | } | |
2226 | anon_vma_lock_write(src_anon_vma); | |
2227 | ||
2228 | dst_ptl = pmd_lockptr(mm, dst_pmd); | |
2229 | double_pt_lock(src_ptl, dst_ptl); | |
2230 | if (unlikely(!pmd_same(*src_pmd, src_pmdval) || | |
2231 | !pmd_same(*dst_pmd, dst_pmdval))) { | |
2232 | err = -EAGAIN; | |
2233 | goto unlock_ptls; | |
2234 | } | |
2235 | if (folio_maybe_dma_pinned(src_folio) || | |
2236 | !PageAnonExclusive(&src_folio->page)) { | |
2237 | err = -EBUSY; | |
2238 | goto unlock_ptls; | |
2239 | } | |
2240 | ||
2241 | if (WARN_ON_ONCE(!folio_test_head(src_folio)) || | |
2242 | WARN_ON_ONCE(!folio_test_anon(src_folio))) { | |
2243 | err = -EBUSY; | |
2244 | goto unlock_ptls; | |
2245 | } | |
2246 | ||
2247 | folio_move_anon_rmap(src_folio, dst_vma); | |
2248 | WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); | |
2249 | ||
2250 | src_pmdval = pmdp_huge_clear_flush(src_vma, src_addr, src_pmd); | |
2251 | /* Folio got pinned from under us. Put it back and fail the move. */ | |
2252 | if (folio_maybe_dma_pinned(src_folio)) { | |
2253 | set_pmd_at(mm, src_addr, src_pmd, src_pmdval); | |
2254 | err = -EBUSY; | |
2255 | goto unlock_ptls; | |
2256 | } | |
2257 | ||
2258 | _dst_pmd = mk_huge_pmd(&src_folio->page, dst_vma->vm_page_prot); | |
2259 | /* Follow mremap() behavior and treat the entry dirty after the move */ | |
2260 | _dst_pmd = pmd_mkwrite(pmd_mkdirty(_dst_pmd), dst_vma); | |
2261 | set_pmd_at(mm, dst_addr, dst_pmd, _dst_pmd); | |
2262 | ||
2263 | src_pgtable = pgtable_trans_huge_withdraw(mm, src_pmd); | |
2264 | pgtable_trans_huge_deposit(mm, dst_pmd, src_pgtable); | |
2265 | unlock_ptls: | |
2266 | double_pt_unlock(src_ptl, dst_ptl); | |
2267 | anon_vma_unlock_write(src_anon_vma); | |
2268 | put_anon_vma(src_anon_vma); | |
2269 | unlock_folio: | |
2270 | /* unblock rmap walks */ | |
2271 | folio_unlock(src_folio); | |
2272 | mmu_notifier_invalidate_range_end(&range); | |
2273 | folio_put(src_folio); | |
2274 | return err; | |
2275 | } | |
2276 | #endif /* CONFIG_USERFAULTFD */ | |
2277 | ||
025c5b24 | 2278 | /* |
8f19b0c0 | 2279 | * Returns page table lock pointer if a given pmd maps a thp, NULL otherwise. |
025c5b24 | 2280 | * |
8f19b0c0 HY |
2281 | * Note that if it returns page table lock pointer, this routine returns without |
2282 | * unlocking page table lock. So callers must unlock it. | |
025c5b24 | 2283 | */ |
b6ec57f4 | 2284 | spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) |
025c5b24 | 2285 | { |
b6ec57f4 KS |
2286 | spinlock_t *ptl; |
2287 | ptl = pmd_lock(vma->vm_mm, pmd); | |
84c3fc4e ZY |
2288 | if (likely(is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || |
2289 | pmd_devmap(*pmd))) | |
b6ec57f4 KS |
2290 | return ptl; |
2291 | spin_unlock(ptl); | |
2292 | return NULL; | |
cd7548ab JW |
2293 | } |
2294 | ||
a00cc7d9 | 2295 | /* |
d965e390 | 2296 | * Returns page table lock pointer if a given pud maps a thp, NULL otherwise. |
a00cc7d9 | 2297 | * |
d965e390 ML |
2298 | * Note that if it returns page table lock pointer, this routine returns without |
2299 | * unlocking page table lock. So callers must unlock it. | |
a00cc7d9 MW |
2300 | */ |
2301 | spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma) | |
2302 | { | |
2303 | spinlock_t *ptl; | |
2304 | ||
2305 | ptl = pud_lock(vma->vm_mm, pud); | |
2306 | if (likely(pud_trans_huge(*pud) || pud_devmap(*pud))) | |
2307 | return ptl; | |
2308 | spin_unlock(ptl); | |
2309 | return NULL; | |
2310 | } | |
2311 | ||
2312 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD | |
2313 | int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
2314 | pud_t *pud, unsigned long addr) | |
2315 | { | |
a00cc7d9 MW |
2316 | spinlock_t *ptl; |
2317 | ||
2318 | ptl = __pud_trans_huge_lock(pud, vma); | |
2319 | if (!ptl) | |
2320 | return 0; | |
74929079 | 2321 | |
f32928ab | 2322 | pudp_huge_get_and_clear_full(vma, addr, pud, tlb->fullmm); |
a00cc7d9 | 2323 | tlb_remove_pud_tlb_entry(tlb, pud, addr); |
2484ca9b | 2324 | if (vma_is_special_huge(vma)) { |
a00cc7d9 MW |
2325 | spin_unlock(ptl); |
2326 | /* No zero page support yet */ | |
2327 | } else { | |
2328 | /* No support for anonymous PUD pages yet */ | |
2329 | BUG(); | |
2330 | } | |
2331 | return 1; | |
2332 | } | |
2333 | ||
2334 | static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud, | |
2335 | unsigned long haddr) | |
2336 | { | |
2337 | VM_BUG_ON(haddr & ~HPAGE_PUD_MASK); | |
2338 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); | |
2339 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma); | |
2340 | VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud)); | |
2341 | ||
ce9311cf | 2342 | count_vm_event(THP_SPLIT_PUD); |
a00cc7d9 | 2343 | |
ec8832d0 | 2344 | pudp_huge_clear_flush(vma, haddr, pud); |
a00cc7d9 MW |
2345 | } |
2346 | ||
2347 | void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud, | |
2348 | unsigned long address) | |
2349 | { | |
2350 | spinlock_t *ptl; | |
ac46d4f3 | 2351 | struct mmu_notifier_range range; |
a00cc7d9 | 2352 | |
7d4a8be0 | 2353 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
6f4f13e8 | 2354 | address & HPAGE_PUD_MASK, |
ac46d4f3 JG |
2355 | (address & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE); |
2356 | mmu_notifier_invalidate_range_start(&range); | |
2357 | ptl = pud_lock(vma->vm_mm, pud); | |
a00cc7d9 MW |
2358 | if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud))) |
2359 | goto out; | |
ac46d4f3 | 2360 | __split_huge_pud_locked(vma, pud, range.start); |
a00cc7d9 MW |
2361 | |
2362 | out: | |
2363 | spin_unlock(ptl); | |
ec8832d0 | 2364 | mmu_notifier_invalidate_range_end(&range); |
a00cc7d9 MW |
2365 | } |
2366 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ | |
2367 | ||
eef1b3ba KS |
2368 | static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, |
2369 | unsigned long haddr, pmd_t *pmd) | |
2370 | { | |
2371 | struct mm_struct *mm = vma->vm_mm; | |
2372 | pgtable_t pgtable; | |
42b2af2c | 2373 | pmd_t _pmd, old_pmd; |
c9c1ee20 HD |
2374 | unsigned long addr; |
2375 | pte_t *pte; | |
eef1b3ba KS |
2376 | int i; |
2377 | ||
0f10851e JG |
2378 | /* |
2379 | * Leave pmd empty until pte is filled note that it is fine to delay | |
2380 | * notification until mmu_notifier_invalidate_range_end() as we are | |
2381 | * replacing a zero pmd write protected page with a zero pte write | |
2382 | * protected page. | |
2383 | * | |
ee65728e | 2384 | * See Documentation/mm/mmu_notifier.rst |
0f10851e | 2385 | */ |
42b2af2c | 2386 | old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd); |
eef1b3ba KS |
2387 | |
2388 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); | |
2389 | pmd_populate(mm, &_pmd, pgtable); | |
2390 | ||
c9c1ee20 HD |
2391 | pte = pte_offset_map(&_pmd, haddr); |
2392 | VM_BUG_ON(!pte); | |
2393 | for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { | |
2394 | pte_t entry; | |
2395 | ||
2396 | entry = pfn_pte(my_zero_pfn(addr), vma->vm_page_prot); | |
eef1b3ba | 2397 | entry = pte_mkspecial(entry); |
42b2af2c DH |
2398 | if (pmd_uffd_wp(old_pmd)) |
2399 | entry = pte_mkuffd_wp(entry); | |
c33c7948 | 2400 | VM_BUG_ON(!pte_none(ptep_get(pte))); |
c9c1ee20 HD |
2401 | set_pte_at(mm, addr, pte, entry); |
2402 | pte++; | |
eef1b3ba | 2403 | } |
c9c1ee20 | 2404 | pte_unmap(pte - 1); |
eef1b3ba KS |
2405 | smp_wmb(); /* make pte visible before pmd */ |
2406 | pmd_populate(mm, pmd, pgtable); | |
eef1b3ba KS |
2407 | } |
2408 | ||
2409 | static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, | |
ba988280 | 2410 | unsigned long haddr, bool freeze) |
eef1b3ba KS |
2411 | { |
2412 | struct mm_struct *mm = vma->vm_mm; | |
91b2978a | 2413 | struct folio *folio; |
eef1b3ba KS |
2414 | struct page *page; |
2415 | pgtable_t pgtable; | |
423ac9af | 2416 | pmd_t old_pmd, _pmd; |
292924b2 | 2417 | bool young, write, soft_dirty, pmd_migration = false, uffd_wp = false; |
0ccf7f16 | 2418 | bool anon_exclusive = false, dirty = false; |
2ac015e2 | 2419 | unsigned long addr; |
c9c1ee20 | 2420 | pte_t *pte; |
eef1b3ba KS |
2421 | int i; |
2422 | ||
2423 | VM_BUG_ON(haddr & ~HPAGE_PMD_MASK); | |
2424 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); | |
2425 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PMD_SIZE, vma); | |
84c3fc4e ZY |
2426 | VM_BUG_ON(!is_pmd_migration_entry(*pmd) && !pmd_trans_huge(*pmd) |
2427 | && !pmd_devmap(*pmd)); | |
eef1b3ba KS |
2428 | |
2429 | count_vm_event(THP_SPLIT_PMD); | |
2430 | ||
d21b9e57 | 2431 | if (!vma_is_anonymous(vma)) { |
ec8832d0 | 2432 | old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd); |
953c66c2 AK |
2433 | /* |
2434 | * We are going to unmap this huge page. So | |
2435 | * just go ahead and zap it | |
2436 | */ | |
2437 | if (arch_needs_pgtable_deposit()) | |
2438 | zap_deposited_table(mm, pmd); | |
2484ca9b | 2439 | if (vma_is_special_huge(vma)) |
d21b9e57 | 2440 | return; |
99fa8a48 HD |
2441 | if (unlikely(is_pmd_migration_entry(old_pmd))) { |
2442 | swp_entry_t entry; | |
2443 | ||
2444 | entry = pmd_to_swp_entry(old_pmd); | |
af5cdaf8 | 2445 | page = pfn_swap_entry_to_page(entry); |
99fa8a48 HD |
2446 | } else { |
2447 | page = pmd_page(old_pmd); | |
a8e61d58 DH |
2448 | folio = page_folio(page); |
2449 | if (!folio_test_dirty(folio) && pmd_dirty(old_pmd)) | |
db44c658 | 2450 | folio_mark_dirty(folio); |
a8e61d58 DH |
2451 | if (!folio_test_referenced(folio) && pmd_young(old_pmd)) |
2452 | folio_set_referenced(folio); | |
2453 | folio_remove_rmap_pmd(folio, page, vma); | |
2454 | folio_put(folio); | |
99fa8a48 | 2455 | } |
fadae295 | 2456 | add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR); |
eef1b3ba | 2457 | return; |
99fa8a48 HD |
2458 | } |
2459 | ||
3b77e8c8 | 2460 | if (is_huge_zero_pmd(*pmd)) { |
4645b9fe JG |
2461 | /* |
2462 | * FIXME: Do we want to invalidate secondary mmu by calling | |
1af5a810 AP |
2463 | * mmu_notifier_arch_invalidate_secondary_tlbs() see comments below |
2464 | * inside __split_huge_pmd() ? | |
4645b9fe JG |
2465 | * |
2466 | * We are going from a zero huge page write protected to zero | |
2467 | * small page also write protected so it does not seems useful | |
2468 | * to invalidate secondary mmu at this time. | |
2469 | */ | |
eef1b3ba KS |
2470 | return __split_huge_zero_page_pmd(vma, haddr, pmd); |
2471 | } | |
2472 | ||
423ac9af AK |
2473 | /* |
2474 | * Up to this point the pmd is present and huge and userland has the | |
2475 | * whole access to the hugepage during the split (which happens in | |
2476 | * place). If we overwrite the pmd with the not-huge version pointing | |
2477 | * to the pte here (which of course we could if all CPUs were bug | |
2478 | * free), userland could trigger a small page size TLB miss on the | |
2479 | * small sized TLB while the hugepage TLB entry is still established in | |
2480 | * the huge TLB. Some CPU doesn't like that. | |
42742d9b AK |
2481 | * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum |
2482 | * 383 on page 105. Intel should be safe but is also warns that it's | |
423ac9af AK |
2483 | * only safe if the permission and cache attributes of the two entries |
2484 | * loaded in the two TLB is identical (which should be the case here). | |
2485 | * But it is generally safer to never allow small and huge TLB entries | |
2486 | * for the same virtual address to be loaded simultaneously. So instead | |
2487 | * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the | |
2488 | * current pmd notpresent (atomically because here the pmd_trans_huge | |
2489 | * must remain set at all times on the pmd until the split is complete | |
2490 | * for this pmd), then we flush the SMP TLB and finally we write the | |
2491 | * non-huge version of the pmd entry with pmd_populate. | |
2492 | */ | |
2493 | old_pmd = pmdp_invalidate(vma, haddr, pmd); | |
2494 | ||
423ac9af | 2495 | pmd_migration = is_pmd_migration_entry(old_pmd); |
2e83ee1d | 2496 | if (unlikely(pmd_migration)) { |
84c3fc4e ZY |
2497 | swp_entry_t entry; |
2498 | ||
423ac9af | 2499 | entry = pmd_to_swp_entry(old_pmd); |
af5cdaf8 | 2500 | page = pfn_swap_entry_to_page(entry); |
4dd845b5 | 2501 | write = is_writable_migration_entry(entry); |
6c287605 DH |
2502 | if (PageAnon(page)) |
2503 | anon_exclusive = is_readable_exclusive_migration_entry(entry); | |
2e346877 PX |
2504 | young = is_migration_entry_young(entry); |
2505 | dirty = is_migration_entry_dirty(entry); | |
2e83ee1d | 2506 | soft_dirty = pmd_swp_soft_dirty(old_pmd); |
f45ec5ff | 2507 | uffd_wp = pmd_swp_uffd_wp(old_pmd); |
2e83ee1d | 2508 | } else { |
423ac9af | 2509 | page = pmd_page(old_pmd); |
91b2978a | 2510 | folio = page_folio(page); |
0ccf7f16 PX |
2511 | if (pmd_dirty(old_pmd)) { |
2512 | dirty = true; | |
91b2978a | 2513 | folio_set_dirty(folio); |
0ccf7f16 | 2514 | } |
2e83ee1d PX |
2515 | write = pmd_write(old_pmd); |
2516 | young = pmd_young(old_pmd); | |
2517 | soft_dirty = pmd_soft_dirty(old_pmd); | |
292924b2 | 2518 | uffd_wp = pmd_uffd_wp(old_pmd); |
6c287605 | 2519 | |
91b2978a DH |
2520 | VM_WARN_ON_FOLIO(!folio_ref_count(folio), folio); |
2521 | VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio); | |
6c287605 DH |
2522 | |
2523 | /* | |
2524 | * Without "freeze", we'll simply split the PMD, propagating the | |
2525 | * PageAnonExclusive() flag for each PTE by setting it for | |
2526 | * each subpage -- no need to (temporarily) clear. | |
2527 | * | |
2528 | * With "freeze" we want to replace mapped pages by | |
2529 | * migration entries right away. This is only possible if we | |
2530 | * managed to clear PageAnonExclusive() -- see | |
2531 | * set_pmd_migration_entry(). | |
2532 | * | |
2533 | * In case we cannot clear PageAnonExclusive(), split the PMD | |
2534 | * only and let try_to_migrate_one() fail later. | |
088b8aa5 | 2535 | * |
e3b4b137 | 2536 | * See folio_try_share_anon_rmap_pmd(): invalidate PMD first. |
6c287605 | 2537 | */ |
91b2978a | 2538 | anon_exclusive = PageAnonExclusive(page); |
e3b4b137 DH |
2539 | if (freeze && anon_exclusive && |
2540 | folio_try_share_anon_rmap_pmd(folio, page)) | |
6c287605 | 2541 | freeze = false; |
91b2978a DH |
2542 | if (!freeze) { |
2543 | rmap_t rmap_flags = RMAP_NONE; | |
2544 | ||
2545 | folio_ref_add(folio, HPAGE_PMD_NR - 1); | |
2546 | if (anon_exclusive) | |
2547 | rmap_flags |= RMAP_EXCLUSIVE; | |
2548 | folio_add_anon_rmap_ptes(folio, page, HPAGE_PMD_NR, | |
2549 | vma, haddr, rmap_flags); | |
2550 | } | |
2e83ee1d | 2551 | } |
eef1b3ba | 2552 | |
423ac9af AK |
2553 | /* |
2554 | * Withdraw the table only after we mark the pmd entry invalid. | |
2555 | * This's critical for some architectures (Power). | |
2556 | */ | |
eef1b3ba KS |
2557 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); |
2558 | pmd_populate(mm, &_pmd, pgtable); | |
2559 | ||
c9c1ee20 HD |
2560 | pte = pte_offset_map(&_pmd, haddr); |
2561 | VM_BUG_ON(!pte); | |
2ac015e2 | 2562 | for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { |
c9c1ee20 | 2563 | pte_t entry; |
eef1b3ba KS |
2564 | /* |
2565 | * Note that NUMA hinting access restrictions are not | |
2566 | * transferred to avoid any possibility of altering | |
2567 | * permissions across VMAs. | |
2568 | */ | |
84c3fc4e | 2569 | if (freeze || pmd_migration) { |
ba988280 | 2570 | swp_entry_t swp_entry; |
4dd845b5 AP |
2571 | if (write) |
2572 | swp_entry = make_writable_migration_entry( | |
2573 | page_to_pfn(page + i)); | |
6c287605 DH |
2574 | else if (anon_exclusive) |
2575 | swp_entry = make_readable_exclusive_migration_entry( | |
2576 | page_to_pfn(page + i)); | |
4dd845b5 AP |
2577 | else |
2578 | swp_entry = make_readable_migration_entry( | |
2579 | page_to_pfn(page + i)); | |
2e346877 PX |
2580 | if (young) |
2581 | swp_entry = make_migration_entry_young(swp_entry); | |
2582 | if (dirty) | |
2583 | swp_entry = make_migration_entry_dirty(swp_entry); | |
ba988280 | 2584 | entry = swp_entry_to_pte(swp_entry); |
804dd150 AA |
2585 | if (soft_dirty) |
2586 | entry = pte_swp_mksoft_dirty(entry); | |
f45ec5ff PX |
2587 | if (uffd_wp) |
2588 | entry = pte_swp_mkuffd_wp(entry); | |
ba988280 | 2589 | } else { |
6d2329f8 | 2590 | entry = mk_pte(page + i, READ_ONCE(vma->vm_page_prot)); |
1462c52e | 2591 | if (write) |
161e393c | 2592 | entry = pte_mkwrite(entry, vma); |
ba988280 KS |
2593 | if (!young) |
2594 | entry = pte_mkold(entry); | |
e833bc50 PX |
2595 | /* NOTE: this may set soft-dirty too on some archs */ |
2596 | if (dirty) | |
2597 | entry = pte_mkdirty(entry); | |
804dd150 AA |
2598 | if (soft_dirty) |
2599 | entry = pte_mksoft_dirty(entry); | |
292924b2 PX |
2600 | if (uffd_wp) |
2601 | entry = pte_mkuffd_wp(entry); | |
ba988280 | 2602 | } |
c33c7948 | 2603 | VM_BUG_ON(!pte_none(ptep_get(pte))); |
2ac015e2 | 2604 | set_pte_at(mm, addr, pte, entry); |
c9c1ee20 | 2605 | pte++; |
eef1b3ba | 2606 | } |
c9c1ee20 | 2607 | pte_unmap(pte - 1); |
eef1b3ba | 2608 | |
cb67f428 | 2609 | if (!pmd_migration) |
a8e61d58 | 2610 | folio_remove_rmap_pmd(folio, page, vma); |
96d82deb HD |
2611 | if (freeze) |
2612 | put_page(page); | |
eef1b3ba KS |
2613 | |
2614 | smp_wmb(); /* make pte visible before pmd */ | |
2615 | pmd_populate(mm, pmd, pgtable); | |
2616 | } | |
2617 | ||
2618 | void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, | |
af28a988 | 2619 | unsigned long address, bool freeze, struct folio *folio) |
eef1b3ba KS |
2620 | { |
2621 | spinlock_t *ptl; | |
ac46d4f3 | 2622 | struct mmu_notifier_range range; |
eef1b3ba | 2623 | |
7d4a8be0 | 2624 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
6f4f13e8 | 2625 | address & HPAGE_PMD_MASK, |
ac46d4f3 JG |
2626 | (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE); |
2627 | mmu_notifier_invalidate_range_start(&range); | |
2628 | ptl = pmd_lock(vma->vm_mm, pmd); | |
33f4751e NH |
2629 | |
2630 | /* | |
af28a988 MWO |
2631 | * If caller asks to setup a migration entry, we need a folio to check |
2632 | * pmd against. Otherwise we can end up replacing wrong folio. | |
33f4751e | 2633 | */ |
af28a988 | 2634 | VM_BUG_ON(freeze && !folio); |
83a8441f | 2635 | VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); |
33f4751e | 2636 | |
7f760917 | 2637 | if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || |
83a8441f | 2638 | is_pmd_migration_entry(*pmd)) { |
cea33328 ML |
2639 | /* |
2640 | * It's safe to call pmd_page when folio is set because it's | |
2641 | * guaranteed that pmd is present. | |
2642 | */ | |
83a8441f MWO |
2643 | if (folio && folio != page_folio(pmd_page(*pmd))) |
2644 | goto out; | |
7f760917 | 2645 | __split_huge_pmd_locked(vma, pmd, range.start, freeze); |
83a8441f | 2646 | } |
7f760917 | 2647 | |
e90309c9 | 2648 | out: |
eef1b3ba | 2649 | spin_unlock(ptl); |
ec8832d0 | 2650 | mmu_notifier_invalidate_range_end(&range); |
eef1b3ba KS |
2651 | } |
2652 | ||
fec89c10 | 2653 | void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, |
af28a988 | 2654 | bool freeze, struct folio *folio) |
94fcc585 | 2655 | { |
50722804 | 2656 | pmd_t *pmd = mm_find_pmd(vma->vm_mm, address); |
94fcc585 | 2657 | |
50722804 | 2658 | if (!pmd) |
f72e7dcd HD |
2659 | return; |
2660 | ||
af28a988 | 2661 | __split_huge_pmd(vma, pmd, address, freeze, folio); |
94fcc585 AA |
2662 | } |
2663 | ||
71f9e58e ML |
2664 | static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address) |
2665 | { | |
2666 | /* | |
2667 | * If the new address isn't hpage aligned and it could previously | |
2668 | * contain an hugepage: check if we need to split an huge pmd. | |
2669 | */ | |
2670 | if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) && | |
2671 | range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE), | |
2672 | ALIGN(address, HPAGE_PMD_SIZE))) | |
2673 | split_huge_pmd_address(vma, address, false, NULL); | |
2674 | } | |
2675 | ||
e1b9996b | 2676 | void vma_adjust_trans_huge(struct vm_area_struct *vma, |
94fcc585 AA |
2677 | unsigned long start, |
2678 | unsigned long end, | |
2679 | long adjust_next) | |
2680 | { | |
71f9e58e ML |
2681 | /* Check if we need to split start first. */ |
2682 | split_huge_pmd_if_needed(vma, start); | |
94fcc585 | 2683 | |
71f9e58e ML |
2684 | /* Check if we need to split end next. */ |
2685 | split_huge_pmd_if_needed(vma, end); | |
94fcc585 AA |
2686 | |
2687 | /* | |
68540502 | 2688 | * If we're also updating the next vma vm_start, |
71f9e58e | 2689 | * check if we need to split it. |
94fcc585 AA |
2690 | */ |
2691 | if (adjust_next > 0) { | |
68540502 | 2692 | struct vm_area_struct *next = find_vma(vma->vm_mm, vma->vm_end); |
94fcc585 | 2693 | unsigned long nstart = next->vm_start; |
f9d86a60 | 2694 | nstart += adjust_next; |
71f9e58e | 2695 | split_huge_pmd_if_needed(next, nstart); |
94fcc585 AA |
2696 | } |
2697 | } | |
e9b61f19 | 2698 | |
684555aa | 2699 | static void unmap_folio(struct folio *folio) |
e9b61f19 | 2700 | { |
a98a2f0c | 2701 | enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD | |
3027c6f8 | 2702 | TTU_SYNC | TTU_BATCH_FLUSH; |
e9b61f19 | 2703 | |
684555aa | 2704 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
e9b61f19 | 2705 | |
a98a2f0c AP |
2706 | /* |
2707 | * Anon pages need migration entries to preserve them, but file | |
2708 | * pages can simply be left unmapped, then faulted back on demand. | |
2709 | * If that is ever changed (perhaps for mlock), update remap_page(). | |
2710 | */ | |
4b8554c5 MWO |
2711 | if (folio_test_anon(folio)) |
2712 | try_to_migrate(folio, ttu_flags); | |
a98a2f0c | 2713 | else |
869f7ee6 | 2714 | try_to_unmap(folio, ttu_flags | TTU_IGNORE_MLOCK); |
3027c6f8 BW |
2715 | |
2716 | try_to_unmap_flush(); | |
e9b61f19 KS |
2717 | } |
2718 | ||
4eecb8b9 | 2719 | static void remap_page(struct folio *folio, unsigned long nr) |
e9b61f19 | 2720 | { |
4eecb8b9 | 2721 | int i = 0; |
ab02c252 | 2722 | |
684555aa | 2723 | /* If unmap_folio() uses try_to_migrate() on file, remove this check */ |
4eecb8b9 | 2724 | if (!folio_test_anon(folio)) |
ab02c252 | 2725 | return; |
4eecb8b9 MWO |
2726 | for (;;) { |
2727 | remove_migration_ptes(folio, folio, true); | |
2728 | i += folio_nr_pages(folio); | |
2729 | if (i >= nr) | |
2730 | break; | |
2731 | folio = folio_next(folio); | |
ace71a19 | 2732 | } |
e9b61f19 KS |
2733 | } |
2734 | ||
94866635 | 2735 | static void lru_add_page_tail(struct page *head, struct page *tail, |
88dcb9a3 AS |
2736 | struct lruvec *lruvec, struct list_head *list) |
2737 | { | |
94866635 AS |
2738 | VM_BUG_ON_PAGE(!PageHead(head), head); |
2739 | VM_BUG_ON_PAGE(PageCompound(tail), head); | |
2740 | VM_BUG_ON_PAGE(PageLRU(tail), head); | |
6168d0da | 2741 | lockdep_assert_held(&lruvec->lru_lock); |
88dcb9a3 | 2742 | |
6dbb5741 | 2743 | if (list) { |
88dcb9a3 | 2744 | /* page reclaim is reclaiming a huge page */ |
6dbb5741 | 2745 | VM_WARN_ON(PageLRU(head)); |
94866635 AS |
2746 | get_page(tail); |
2747 | list_add_tail(&tail->lru, list); | |
88dcb9a3 | 2748 | } else { |
6dbb5741 AS |
2749 | /* head is still on lru (and we have it frozen) */ |
2750 | VM_WARN_ON(!PageLRU(head)); | |
07ca7606 HD |
2751 | if (PageUnevictable(tail)) |
2752 | tail->mlock_count = 0; | |
2753 | else | |
2754 | list_add_tail(&tail->lru, &head->lru); | |
6dbb5741 | 2755 | SetPageLRU(tail); |
88dcb9a3 AS |
2756 | } |
2757 | } | |
2758 | ||
07e09c48 | 2759 | static void __split_huge_page_tail(struct folio *folio, int tail, |
e9b61f19 KS |
2760 | struct lruvec *lruvec, struct list_head *list) |
2761 | { | |
07e09c48 | 2762 | struct page *head = &folio->page; |
e9b61f19 | 2763 | struct page *page_tail = head + tail; |
07e09c48 DH |
2764 | /* |
2765 | * Careful: new_folio is not a "real" folio before we cleared PageTail. | |
2766 | * Don't pass it around before clear_compound_head(). | |
2767 | */ | |
2768 | struct folio *new_folio = (struct folio *)page_tail; | |
e9b61f19 | 2769 | |
8df651c7 | 2770 | VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail); |
e9b61f19 KS |
2771 | |
2772 | /* | |
605ca5ed KK |
2773 | * Clone page flags before unfreezing refcount. |
2774 | * | |
2775 | * After successful get_page_unless_zero() might follow flags change, | |
8958b249 | 2776 | * for example lock_page() which set PG_waiters. |
6c287605 DH |
2777 | * |
2778 | * Note that for mapped sub-pages of an anonymous THP, | |
684555aa | 2779 | * PG_anon_exclusive has been cleared in unmap_folio() and is stored in |
6c287605 DH |
2780 | * the migration entry instead from where remap_page() will restore it. |
2781 | * We can still have PG_anon_exclusive set on effectively unmapped and | |
2782 | * unreferenced sub-pages of an anonymous THP: we can simply drop | |
2783 | * PG_anon_exclusive (-> PG_mappedtodisk) for these here. | |
e9b61f19 | 2784 | */ |
e9b61f19 KS |
2785 | page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
2786 | page_tail->flags |= (head->flags & | |
2787 | ((1L << PG_referenced) | | |
2788 | (1L << PG_swapbacked) | | |
38d8b4e6 | 2789 | (1L << PG_swapcache) | |
e9b61f19 KS |
2790 | (1L << PG_mlocked) | |
2791 | (1L << PG_uptodate) | | |
2792 | (1L << PG_active) | | |
1899ad18 | 2793 | (1L << PG_workingset) | |
e9b61f19 | 2794 | (1L << PG_locked) | |
b8d3c4c3 | 2795 | (1L << PG_unevictable) | |
b0284cd2 | 2796 | #ifdef CONFIG_ARCH_USES_PG_ARCH_X |
72e6afa0 | 2797 | (1L << PG_arch_2) | |
ef6458b1 | 2798 | (1L << PG_arch_3) | |
72e6afa0 | 2799 | #endif |
ec1c86b2 YZ |
2800 | (1L << PG_dirty) | |
2801 | LRU_GEN_MASK | LRU_REFS_MASK)); | |
e9b61f19 | 2802 | |
cb67f428 | 2803 | /* ->mapping in first and second tail page is replaced by other uses */ |
173d9d9f HD |
2804 | VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING, |
2805 | page_tail); | |
2806 | page_tail->mapping = head->mapping; | |
2807 | page_tail->index = head->index + tail; | |
71e2d666 MG |
2808 | |
2809 | /* | |
cfeed8ff DH |
2810 | * page->private should not be set in tail pages. Fix up and warn once |
2811 | * if private is unexpectedly set. | |
71e2d666 | 2812 | */ |
cfeed8ff DH |
2813 | if (unlikely(page_tail->private)) { |
2814 | VM_WARN_ON_ONCE_PAGE(true, page_tail); | |
71e2d666 MG |
2815 | page_tail->private = 0; |
2816 | } | |
07e09c48 DH |
2817 | if (folio_test_swapcache(folio)) |
2818 | new_folio->swap.val = folio->swap.val + tail; | |
173d9d9f | 2819 | |
605ca5ed | 2820 | /* Page flags must be visible before we make the page non-compound. */ |
e9b61f19 KS |
2821 | smp_wmb(); |
2822 | ||
605ca5ed KK |
2823 | /* |
2824 | * Clear PageTail before unfreezing page refcount. | |
2825 | * | |
2826 | * After successful get_page_unless_zero() might follow put_page() | |
2827 | * which needs correct compound_head(). | |
2828 | */ | |
e9b61f19 KS |
2829 | clear_compound_head(page_tail); |
2830 | ||
605ca5ed | 2831 | /* Finally unfreeze refcount. Additional reference from page cache. */ |
b7542769 KW |
2832 | page_ref_unfreeze(page_tail, 1 + (!folio_test_anon(folio) || |
2833 | folio_test_swapcache(folio))); | |
605ca5ed | 2834 | |
b7542769 KW |
2835 | if (folio_test_young(folio)) |
2836 | folio_set_young(new_folio); | |
2837 | if (folio_test_idle(folio)) | |
2838 | folio_set_idle(new_folio); | |
e9b61f19 | 2839 | |
c8253011 | 2840 | folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio)); |
94723aaf MH |
2841 | |
2842 | /* | |
2843 | * always add to the tail because some iterators expect new | |
2844 | * pages to show after the currently processed elements - e.g. | |
2845 | * migrate_pages | |
2846 | */ | |
e9b61f19 | 2847 | lru_add_page_tail(head, page_tail, lruvec, list); |
e9b61f19 KS |
2848 | } |
2849 | ||
baa355fd | 2850 | static void __split_huge_page(struct page *page, struct list_head *list, |
b6769834 | 2851 | pgoff_t end) |
e9b61f19 | 2852 | { |
e809c3fe MWO |
2853 | struct folio *folio = page_folio(page); |
2854 | struct page *head = &folio->page; | |
e9b61f19 | 2855 | struct lruvec *lruvec; |
4101196b MWO |
2856 | struct address_space *swap_cache = NULL; |
2857 | unsigned long offset = 0; | |
8cce5475 | 2858 | unsigned int nr = thp_nr_pages(head); |
509f0069 | 2859 | int i, nr_dropped = 0; |
e9b61f19 | 2860 | |
e9b61f19 | 2861 | /* complete memcg works before add pages to LRU */ |
be6c8982 | 2862 | split_page_memcg(head, nr); |
e9b61f19 | 2863 | |
07e09c48 DH |
2864 | if (folio_test_anon(folio) && folio_test_swapcache(folio)) { |
2865 | offset = swp_offset(folio->swap); | |
2866 | swap_cache = swap_address_space(folio->swap); | |
4101196b MWO |
2867 | xa_lock(&swap_cache->i_pages); |
2868 | } | |
2869 | ||
f0953a1b | 2870 | /* lock lru list/PageCompound, ref frozen by page_ref_freeze */ |
e809c3fe | 2871 | lruvec = folio_lruvec_lock(folio); |
b6769834 | 2872 | |
eac96c3e YS |
2873 | ClearPageHasHWPoisoned(head); |
2874 | ||
8cce5475 | 2875 | for (i = nr - 1; i >= 1; i--) { |
07e09c48 | 2876 | __split_huge_page_tail(folio, i, lruvec, list); |
d144bf62 | 2877 | /* Some pages can be beyond EOF: drop them from page cache */ |
baa355fd | 2878 | if (head[i].index >= end) { |
fb5c2029 MWO |
2879 | struct folio *tail = page_folio(head + i); |
2880 | ||
d144bf62 | 2881 | if (shmem_mapping(head->mapping)) |
509f0069 | 2882 | nr_dropped++; |
fb5c2029 MWO |
2883 | else if (folio_test_clear_dirty(tail)) |
2884 | folio_account_cleaned(tail, | |
2885 | inode_to_wb(folio->mapping->host)); | |
2886 | __filemap_remove_folio(tail, NULL); | |
2887 | folio_put(tail); | |
4101196b MWO |
2888 | } else if (!PageAnon(page)) { |
2889 | __xa_store(&head->mapping->i_pages, head[i].index, | |
2890 | head + i, 0); | |
2891 | } else if (swap_cache) { | |
2892 | __xa_store(&swap_cache->i_pages, offset + i, | |
2893 | head + i, 0); | |
baa355fd KS |
2894 | } |
2895 | } | |
e9b61f19 KS |
2896 | |
2897 | ClearPageCompound(head); | |
6168d0da | 2898 | unlock_page_lruvec(lruvec); |
b6769834 | 2899 | /* Caller disabled irqs, so they are still disabled here */ |
f7da677b | 2900 | |
8cce5475 | 2901 | split_page_owner(head, nr); |
f7da677b | 2902 | |
baa355fd KS |
2903 | /* See comment in __split_huge_page_tail() */ |
2904 | if (PageAnon(head)) { | |
aa5dc07f | 2905 | /* Additional pin to swap cache */ |
4101196b | 2906 | if (PageSwapCache(head)) { |
38d8b4e6 | 2907 | page_ref_add(head, 2); |
4101196b MWO |
2908 | xa_unlock(&swap_cache->i_pages); |
2909 | } else { | |
38d8b4e6 | 2910 | page_ref_inc(head); |
4101196b | 2911 | } |
baa355fd | 2912 | } else { |
aa5dc07f | 2913 | /* Additional pin to page cache */ |
baa355fd | 2914 | page_ref_add(head, 2); |
b93b0163 | 2915 | xa_unlock(&head->mapping->i_pages); |
baa355fd | 2916 | } |
b6769834 | 2917 | local_irq_enable(); |
e9b61f19 | 2918 | |
509f0069 HD |
2919 | if (nr_dropped) |
2920 | shmem_uncharge(head->mapping->host, nr_dropped); | |
4eecb8b9 | 2921 | remap_page(folio, nr); |
e9b61f19 | 2922 | |
07e09c48 DH |
2923 | if (folio_test_swapcache(folio)) |
2924 | split_swap_cluster(folio->swap); | |
c4f9c701 | 2925 | |
8cce5475 | 2926 | for (i = 0; i < nr; i++) { |
e9b61f19 KS |
2927 | struct page *subpage = head + i; |
2928 | if (subpage == page) | |
2929 | continue; | |
2930 | unlock_page(subpage); | |
2931 | ||
2932 | /* | |
2933 | * Subpages may be freed if there wasn't any mapping | |
2934 | * like if add_to_swap() is running on a lru page that | |
2935 | * had its mapping zapped. And freeing these pages | |
2936 | * requires taking the lru_lock so we do the put_page | |
2937 | * of the tail pages after the split is complete. | |
2938 | */ | |
0b175468 | 2939 | free_page_and_swap_cache(subpage); |
e9b61f19 KS |
2940 | } |
2941 | } | |
2942 | ||
b8f593cd | 2943 | /* Racy check whether the huge page can be split */ |
d4b4084a | 2944 | bool can_split_folio(struct folio *folio, int *pextra_pins) |
b8f593cd HY |
2945 | { |
2946 | int extra_pins; | |
2947 | ||
aa5dc07f | 2948 | /* Additional pins from page cache */ |
d4b4084a MWO |
2949 | if (folio_test_anon(folio)) |
2950 | extra_pins = folio_test_swapcache(folio) ? | |
2951 | folio_nr_pages(folio) : 0; | |
b8f593cd | 2952 | else |
d4b4084a | 2953 | extra_pins = folio_nr_pages(folio); |
b8f593cd HY |
2954 | if (pextra_pins) |
2955 | *pextra_pins = extra_pins; | |
d4b4084a | 2956 | return folio_mapcount(folio) == folio_ref_count(folio) - extra_pins - 1; |
b8f593cd HY |
2957 | } |
2958 | ||
e9b61f19 KS |
2959 | /* |
2960 | * This function splits huge page into normal pages. @page can point to any | |
2961 | * subpage of huge page to split. Split doesn't change the position of @page. | |
2962 | * | |
2963 | * Only caller must hold pin on the @page, otherwise split fails with -EBUSY. | |
2964 | * The huge page must be locked. | |
2965 | * | |
2966 | * If @list is null, tail pages will be added to LRU list, otherwise, to @list. | |
2967 | * | |
2968 | * Both head page and tail pages will inherit mapping, flags, and so on from | |
2969 | * the hugepage. | |
2970 | * | |
2971 | * GUP pin and PG_locked transferred to @page. Rest subpages can be freed if | |
2972 | * they are not mapped. | |
2973 | * | |
2974 | * Returns 0 if the hugepage is split successfully. | |
2975 | * Returns -EBUSY if the page is pinned or if anon_vma disappeared from under | |
2976 | * us. | |
2977 | */ | |
2978 | int split_huge_page_to_list(struct page *page, struct list_head *list) | |
2979 | { | |
4eecb8b9 | 2980 | struct folio *folio = page_folio(page); |
f8baa6be | 2981 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
3e9a13da | 2982 | XA_STATE(xas, &folio->mapping->i_pages, folio->index); |
baa355fd KS |
2983 | struct anon_vma *anon_vma = NULL; |
2984 | struct address_space *mapping = NULL; | |
504e070d | 2985 | int extra_pins, ret; |
006d3ff2 | 2986 | pgoff_t end; |
478d134e | 2987 | bool is_hzp; |
e9b61f19 | 2988 | |
3e9a13da MWO |
2989 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
2990 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); | |
e9b61f19 | 2991 | |
3e9a13da | 2992 | is_hzp = is_huge_zero_page(&folio->page); |
4737edbb NH |
2993 | if (is_hzp) { |
2994 | pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); | |
478d134e | 2995 | return -EBUSY; |
4737edbb | 2996 | } |
478d134e | 2997 | |
3e9a13da | 2998 | if (folio_test_writeback(folio)) |
59807685 HY |
2999 | return -EBUSY; |
3000 | ||
3e9a13da | 3001 | if (folio_test_anon(folio)) { |
baa355fd | 3002 | /* |
c1e8d7c6 | 3003 | * The caller does not necessarily hold an mmap_lock that would |
baa355fd KS |
3004 | * prevent the anon_vma disappearing so we first we take a |
3005 | * reference to it and then lock the anon_vma for write. This | |
2f031c6f | 3006 | * is similar to folio_lock_anon_vma_read except the write lock |
baa355fd KS |
3007 | * is taken to serialise against parallel split or collapse |
3008 | * operations. | |
3009 | */ | |
29eea9b5 | 3010 | anon_vma = folio_get_anon_vma(folio); |
baa355fd KS |
3011 | if (!anon_vma) { |
3012 | ret = -EBUSY; | |
3013 | goto out; | |
3014 | } | |
006d3ff2 | 3015 | end = -1; |
baa355fd KS |
3016 | mapping = NULL; |
3017 | anon_vma_lock_write(anon_vma); | |
3018 | } else { | |
6a3edd29 YF |
3019 | gfp_t gfp; |
3020 | ||
3e9a13da | 3021 | mapping = folio->mapping; |
baa355fd KS |
3022 | |
3023 | /* Truncated ? */ | |
3024 | if (!mapping) { | |
3025 | ret = -EBUSY; | |
3026 | goto out; | |
3027 | } | |
3028 | ||
6a3edd29 YF |
3029 | gfp = current_gfp_context(mapping_gfp_mask(mapping) & |
3030 | GFP_RECLAIM_MASK); | |
3031 | ||
0201ebf2 | 3032 | if (!filemap_release_folio(folio, gfp)) { |
6a3edd29 YF |
3033 | ret = -EBUSY; |
3034 | goto out; | |
3035 | } | |
3036 | ||
3e9a13da | 3037 | xas_split_alloc(&xas, folio, folio_order(folio), gfp); |
6b24ca4a MWO |
3038 | if (xas_error(&xas)) { |
3039 | ret = xas_error(&xas); | |
3040 | goto out; | |
3041 | } | |
3042 | ||
baa355fd KS |
3043 | anon_vma = NULL; |
3044 | i_mmap_lock_read(mapping); | |
006d3ff2 HD |
3045 | |
3046 | /* | |
3047 | *__split_huge_page() may need to trim off pages beyond EOF: | |
3048 | * but on 32-bit, i_size_read() takes an irq-unsafe seqlock, | |
3049 | * which cannot be nested inside the page tree lock. So note | |
3050 | * end now: i_size itself may be changed at any moment, but | |
3e9a13da | 3051 | * folio lock is good enough to serialize the trimming. |
006d3ff2 HD |
3052 | */ |
3053 | end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE); | |
d144bf62 HD |
3054 | if (shmem_mapping(mapping)) |
3055 | end = shmem_fallocend(mapping->host, end); | |
e9b61f19 | 3056 | } |
e9b61f19 KS |
3057 | |
3058 | /* | |
684555aa | 3059 | * Racy check if we can split the page, before unmap_folio() will |
e9b61f19 KS |
3060 | * split PMDs |
3061 | */ | |
d4b4084a | 3062 | if (!can_split_folio(folio, &extra_pins)) { |
fd4a7ac3 | 3063 | ret = -EAGAIN; |
e9b61f19 KS |
3064 | goto out_unlock; |
3065 | } | |
3066 | ||
684555aa | 3067 | unmap_folio(folio); |
e9b61f19 | 3068 | |
b6769834 AS |
3069 | /* block interrupt reentry in xa_lock and spinlock */ |
3070 | local_irq_disable(); | |
baa355fd | 3071 | if (mapping) { |
baa355fd | 3072 | /* |
3e9a13da MWO |
3073 | * Check if the folio is present in page cache. |
3074 | * We assume all tail are present too, if folio is there. | |
baa355fd | 3075 | */ |
6b24ca4a MWO |
3076 | xas_lock(&xas); |
3077 | xas_reset(&xas); | |
3e9a13da | 3078 | if (xas_load(&xas) != folio) |
baa355fd KS |
3079 | goto fail; |
3080 | } | |
3081 | ||
0139aa7b | 3082 | /* Prevent deferred_split_scan() touching ->_refcount */ |
364c1eeb | 3083 | spin_lock(&ds_queue->split_queue_lock); |
3e9a13da | 3084 | if (folio_ref_freeze(folio, 1 + extra_pins)) { |
4375a553 | 3085 | if (!list_empty(&folio->_deferred_list)) { |
364c1eeb | 3086 | ds_queue->split_queue_len--; |
4375a553 | 3087 | list_del(&folio->_deferred_list); |
9a982250 | 3088 | } |
afb97172 | 3089 | spin_unlock(&ds_queue->split_queue_lock); |
06d3eff6 | 3090 | if (mapping) { |
3e9a13da | 3091 | int nr = folio_nr_pages(folio); |
bf9ecead | 3092 | |
3e9a13da | 3093 | xas_split(&xas, folio, folio_order(folio)); |
a48d5bdc SR |
3094 | if (folio_test_pmd_mappable(folio)) { |
3095 | if (folio_test_swapbacked(folio)) { | |
3096 | __lruvec_stat_mod_folio(folio, | |
3097 | NR_SHMEM_THPS, -nr); | |
3098 | } else { | |
3099 | __lruvec_stat_mod_folio(folio, | |
3100 | NR_FILE_THPS, -nr); | |
3101 | filemap_nr_thps_dec(mapping); | |
3102 | } | |
1ca7554d | 3103 | } |
06d3eff6 KS |
3104 | } |
3105 | ||
b6769834 | 3106 | __split_huge_page(page, list, end); |
c4f9c701 | 3107 | ret = 0; |
e9b61f19 | 3108 | } else { |
364c1eeb | 3109 | spin_unlock(&ds_queue->split_queue_lock); |
504e070d YS |
3110 | fail: |
3111 | if (mapping) | |
6b24ca4a | 3112 | xas_unlock(&xas); |
b6769834 | 3113 | local_irq_enable(); |
4eecb8b9 | 3114 | remap_page(folio, folio_nr_pages(folio)); |
fd4a7ac3 | 3115 | ret = -EAGAIN; |
e9b61f19 KS |
3116 | } |
3117 | ||
3118 | out_unlock: | |
baa355fd KS |
3119 | if (anon_vma) { |
3120 | anon_vma_unlock_write(anon_vma); | |
3121 | put_anon_vma(anon_vma); | |
3122 | } | |
3123 | if (mapping) | |
3124 | i_mmap_unlock_read(mapping); | |
e9b61f19 | 3125 | out: |
69a37a8b | 3126 | xas_destroy(&xas); |
e9b61f19 KS |
3127 | count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); |
3128 | return ret; | |
3129 | } | |
9a982250 | 3130 | |
8dc4a8f1 | 3131 | void folio_undo_large_rmappable(struct folio *folio) |
9a982250 | 3132 | { |
8dc4a8f1 | 3133 | struct deferred_split *ds_queue; |
9a982250 KS |
3134 | unsigned long flags; |
3135 | ||
deedad80 YF |
3136 | /* |
3137 | * At this point, there is no one trying to add the folio to | |
3138 | * deferred_list. If folio is not in deferred_list, it's safe | |
3139 | * to check without acquiring the split_queue_lock. | |
3140 | */ | |
8dc4a8f1 MWO |
3141 | if (data_race(list_empty(&folio->_deferred_list))) |
3142 | return; | |
3143 | ||
3144 | ds_queue = get_deferred_split_queue(folio); | |
3145 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); | |
3146 | if (!list_empty(&folio->_deferred_list)) { | |
3147 | ds_queue->split_queue_len--; | |
9bcef597 | 3148 | list_del_init(&folio->_deferred_list); |
9a982250 | 3149 | } |
8dc4a8f1 | 3150 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 KS |
3151 | } |
3152 | ||
f158ed61 | 3153 | void deferred_split_folio(struct folio *folio) |
9a982250 | 3154 | { |
f8baa6be | 3155 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
87eaceb3 | 3156 | #ifdef CONFIG_MEMCG |
8991de90 | 3157 | struct mem_cgroup *memcg = folio_memcg(folio); |
87eaceb3 | 3158 | #endif |
9a982250 KS |
3159 | unsigned long flags; |
3160 | ||
8991de90 | 3161 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
9a982250 | 3162 | |
87eaceb3 YS |
3163 | /* |
3164 | * The try_to_unmap() in page reclaim path might reach here too, | |
3165 | * this may cause a race condition to corrupt deferred split queue. | |
8991de90 | 3166 | * And, if page reclaim is already handling the same folio, it is |
87eaceb3 YS |
3167 | * unnecessary to handle it again in shrinker. |
3168 | * | |
8991de90 MWO |
3169 | * Check the swapcache flag to determine if the folio is being |
3170 | * handled by page reclaim since THP swap would add the folio into | |
87eaceb3 YS |
3171 | * swap cache before calling try_to_unmap(). |
3172 | */ | |
8991de90 | 3173 | if (folio_test_swapcache(folio)) |
87eaceb3 YS |
3174 | return; |
3175 | ||
8991de90 | 3176 | if (!list_empty(&folio->_deferred_list)) |
87eaceb3 YS |
3177 | return; |
3178 | ||
364c1eeb | 3179 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
8991de90 | 3180 | if (list_empty(&folio->_deferred_list)) { |
f9719a03 | 3181 | count_vm_event(THP_DEFERRED_SPLIT_PAGE); |
8991de90 | 3182 | list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); |
364c1eeb | 3183 | ds_queue->split_queue_len++; |
87eaceb3 YS |
3184 | #ifdef CONFIG_MEMCG |
3185 | if (memcg) | |
8991de90 | 3186 | set_shrinker_bit(memcg, folio_nid(folio), |
54d91729 | 3187 | deferred_split_shrinker->id); |
87eaceb3 | 3188 | #endif |
9a982250 | 3189 | } |
364c1eeb | 3190 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 KS |
3191 | } |
3192 | ||
3193 | static unsigned long deferred_split_count(struct shrinker *shrink, | |
3194 | struct shrink_control *sc) | |
3195 | { | |
a3d0a918 | 3196 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
364c1eeb | 3197 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
87eaceb3 YS |
3198 | |
3199 | #ifdef CONFIG_MEMCG | |
3200 | if (sc->memcg) | |
3201 | ds_queue = &sc->memcg->deferred_split_queue; | |
3202 | #endif | |
364c1eeb | 3203 | return READ_ONCE(ds_queue->split_queue_len); |
9a982250 KS |
3204 | } |
3205 | ||
3206 | static unsigned long deferred_split_scan(struct shrinker *shrink, | |
3207 | struct shrink_control *sc) | |
3208 | { | |
a3d0a918 | 3209 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
364c1eeb | 3210 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
9a982250 | 3211 | unsigned long flags; |
4375a553 MWO |
3212 | LIST_HEAD(list); |
3213 | struct folio *folio, *next; | |
9a982250 KS |
3214 | int split = 0; |
3215 | ||
87eaceb3 YS |
3216 | #ifdef CONFIG_MEMCG |
3217 | if (sc->memcg) | |
3218 | ds_queue = &sc->memcg->deferred_split_queue; | |
3219 | #endif | |
3220 | ||
364c1eeb | 3221 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
9a982250 | 3222 | /* Take pin on all head pages to avoid freeing them under us */ |
4375a553 MWO |
3223 | list_for_each_entry_safe(folio, next, &ds_queue->split_queue, |
3224 | _deferred_list) { | |
3225 | if (folio_try_get(folio)) { | |
3226 | list_move(&folio->_deferred_list, &list); | |
e3ae1953 | 3227 | } else { |
4375a553 MWO |
3228 | /* We lost race with folio_put() */ |
3229 | list_del_init(&folio->_deferred_list); | |
364c1eeb | 3230 | ds_queue->split_queue_len--; |
9a982250 | 3231 | } |
e3ae1953 KS |
3232 | if (!--sc->nr_to_scan) |
3233 | break; | |
9a982250 | 3234 | } |
364c1eeb | 3235 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 | 3236 | |
4375a553 MWO |
3237 | list_for_each_entry_safe(folio, next, &list, _deferred_list) { |
3238 | if (!folio_trylock(folio)) | |
fa41b900 | 3239 | goto next; |
9a982250 | 3240 | /* split_huge_page() removes page from list on success */ |
4375a553 | 3241 | if (!split_folio(folio)) |
9a982250 | 3242 | split++; |
4375a553 | 3243 | folio_unlock(folio); |
fa41b900 | 3244 | next: |
4375a553 | 3245 | folio_put(folio); |
9a982250 KS |
3246 | } |
3247 | ||
364c1eeb YS |
3248 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
3249 | list_splice_tail(&list, &ds_queue->split_queue); | |
3250 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); | |
9a982250 | 3251 | |
cb8d68ec KS |
3252 | /* |
3253 | * Stop shrinker if we didn't split any page, but the queue is empty. | |
3254 | * This can happen if pages were freed under us. | |
3255 | */ | |
364c1eeb | 3256 | if (!split && list_empty(&ds_queue->split_queue)) |
cb8d68ec KS |
3257 | return SHRINK_STOP; |
3258 | return split; | |
9a982250 KS |
3259 | } |
3260 | ||
49071d43 | 3261 | #ifdef CONFIG_DEBUG_FS |
fa6c0231 | 3262 | static void split_huge_pages_all(void) |
49071d43 KS |
3263 | { |
3264 | struct zone *zone; | |
3265 | struct page *page; | |
630e7c5e | 3266 | struct folio *folio; |
49071d43 KS |
3267 | unsigned long pfn, max_zone_pfn; |
3268 | unsigned long total = 0, split = 0; | |
3269 | ||
fa6c0231 | 3270 | pr_debug("Split all THPs\n"); |
a17206da ML |
3271 | for_each_zone(zone) { |
3272 | if (!managed_zone(zone)) | |
3273 | continue; | |
49071d43 KS |
3274 | max_zone_pfn = zone_end_pfn(zone); |
3275 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { | |
a17206da | 3276 | int nr_pages; |
49071d43 | 3277 | |
2b7aa91b | 3278 | page = pfn_to_online_page(pfn); |
630e7c5e KW |
3279 | if (!page || PageTail(page)) |
3280 | continue; | |
3281 | folio = page_folio(page); | |
3282 | if (!folio_try_get(folio)) | |
49071d43 KS |
3283 | continue; |
3284 | ||
630e7c5e | 3285 | if (unlikely(page_folio(page) != folio)) |
49071d43 KS |
3286 | goto next; |
3287 | ||
630e7c5e | 3288 | if (zone != folio_zone(folio)) |
49071d43 KS |
3289 | goto next; |
3290 | ||
630e7c5e KW |
3291 | if (!folio_test_large(folio) |
3292 | || folio_test_hugetlb(folio) | |
3293 | || !folio_test_lru(folio)) | |
49071d43 KS |
3294 | goto next; |
3295 | ||
3296 | total++; | |
630e7c5e KW |
3297 | folio_lock(folio); |
3298 | nr_pages = folio_nr_pages(folio); | |
3299 | if (!split_folio(folio)) | |
49071d43 | 3300 | split++; |
a17206da | 3301 | pfn += nr_pages - 1; |
630e7c5e | 3302 | folio_unlock(folio); |
49071d43 | 3303 | next: |
630e7c5e | 3304 | folio_put(folio); |
fa6c0231 | 3305 | cond_resched(); |
49071d43 KS |
3306 | } |
3307 | } | |
3308 | ||
fa6c0231 ZY |
3309 | pr_debug("%lu of %lu THP split\n", split, total); |
3310 | } | |
49071d43 | 3311 | |
fa6c0231 ZY |
3312 | static inline bool vma_not_suitable_for_thp_split(struct vm_area_struct *vma) |
3313 | { | |
3314 | return vma_is_special_huge(vma) || (vma->vm_flags & VM_IO) || | |
3315 | is_vm_hugetlb_page(vma); | |
3316 | } | |
3317 | ||
3318 | static int split_huge_pages_pid(int pid, unsigned long vaddr_start, | |
3319 | unsigned long vaddr_end) | |
3320 | { | |
3321 | int ret = 0; | |
3322 | struct task_struct *task; | |
3323 | struct mm_struct *mm; | |
3324 | unsigned long total = 0, split = 0; | |
3325 | unsigned long addr; | |
3326 | ||
3327 | vaddr_start &= PAGE_MASK; | |
3328 | vaddr_end &= PAGE_MASK; | |
3329 | ||
3330 | /* Find the task_struct from pid */ | |
3331 | rcu_read_lock(); | |
3332 | task = find_task_by_vpid(pid); | |
3333 | if (!task) { | |
3334 | rcu_read_unlock(); | |
3335 | ret = -ESRCH; | |
3336 | goto out; | |
3337 | } | |
3338 | get_task_struct(task); | |
3339 | rcu_read_unlock(); | |
3340 | ||
3341 | /* Find the mm_struct */ | |
3342 | mm = get_task_mm(task); | |
3343 | put_task_struct(task); | |
3344 | ||
3345 | if (!mm) { | |
3346 | ret = -EINVAL; | |
3347 | goto out; | |
3348 | } | |
3349 | ||
3350 | pr_debug("Split huge pages in pid: %d, vaddr: [0x%lx - 0x%lx]\n", | |
3351 | pid, vaddr_start, vaddr_end); | |
3352 | ||
3353 | mmap_read_lock(mm); | |
3354 | /* | |
3355 | * always increase addr by PAGE_SIZE, since we could have a PTE page | |
3356 | * table filled with PTE-mapped THPs, each of which is distinct. | |
3357 | */ | |
3358 | for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) { | |
74ba2b38 | 3359 | struct vm_area_struct *vma = vma_lookup(mm, addr); |
fa6c0231 | 3360 | struct page *page; |
a644b0ab | 3361 | struct folio *folio; |
fa6c0231 | 3362 | |
74ba2b38 | 3363 | if (!vma) |
fa6c0231 ZY |
3364 | break; |
3365 | ||
3366 | /* skip special VMA and hugetlb VMA */ | |
3367 | if (vma_not_suitable_for_thp_split(vma)) { | |
3368 | addr = vma->vm_end; | |
3369 | continue; | |
3370 | } | |
3371 | ||
3372 | /* FOLL_DUMP to ignore special (like zero) pages */ | |
87d2762e | 3373 | page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP); |
fa6c0231 | 3374 | |
f7091ed6 | 3375 | if (IS_ERR_OR_NULL(page)) |
fa6c0231 ZY |
3376 | continue; |
3377 | ||
a644b0ab MWO |
3378 | folio = page_folio(page); |
3379 | if (!is_transparent_hugepage(folio)) | |
fa6c0231 ZY |
3380 | goto next; |
3381 | ||
3382 | total++; | |
a644b0ab | 3383 | if (!can_split_folio(folio, NULL)) |
fa6c0231 ZY |
3384 | goto next; |
3385 | ||
a644b0ab | 3386 | if (!folio_trylock(folio)) |
fa6c0231 ZY |
3387 | goto next; |
3388 | ||
a644b0ab | 3389 | if (!split_folio(folio)) |
fa6c0231 ZY |
3390 | split++; |
3391 | ||
a644b0ab | 3392 | folio_unlock(folio); |
fa6c0231 | 3393 | next: |
a644b0ab | 3394 | folio_put(folio); |
fa6c0231 ZY |
3395 | cond_resched(); |
3396 | } | |
3397 | mmap_read_unlock(mm); | |
3398 | mmput(mm); | |
3399 | ||
3400 | pr_debug("%lu of %lu THP split\n", split, total); | |
3401 | ||
3402 | out: | |
3403 | return ret; | |
49071d43 | 3404 | } |
fa6c0231 | 3405 | |
fbe37501 ZY |
3406 | static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, |
3407 | pgoff_t off_end) | |
3408 | { | |
3409 | struct filename *file; | |
3410 | struct file *candidate; | |
3411 | struct address_space *mapping; | |
3412 | int ret = -EINVAL; | |
3413 | pgoff_t index; | |
3414 | int nr_pages = 1; | |
3415 | unsigned long total = 0, split = 0; | |
3416 | ||
3417 | file = getname_kernel(file_path); | |
3418 | if (IS_ERR(file)) | |
3419 | return ret; | |
3420 | ||
3421 | candidate = file_open_name(file, O_RDONLY, 0); | |
3422 | if (IS_ERR(candidate)) | |
3423 | goto out; | |
3424 | ||
3425 | pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx]\n", | |
3426 | file_path, off_start, off_end); | |
3427 | ||
3428 | mapping = candidate->f_mapping; | |
3429 | ||
3430 | for (index = off_start; index < off_end; index += nr_pages) { | |
1fb130b2 | 3431 | struct folio *folio = filemap_get_folio(mapping, index); |
fbe37501 ZY |
3432 | |
3433 | nr_pages = 1; | |
66dabbb6 | 3434 | if (IS_ERR(folio)) |
fbe37501 ZY |
3435 | continue; |
3436 | ||
9ee2c086 | 3437 | if (!folio_test_large(folio)) |
fbe37501 ZY |
3438 | goto next; |
3439 | ||
3440 | total++; | |
9ee2c086 | 3441 | nr_pages = folio_nr_pages(folio); |
fbe37501 | 3442 | |
9ee2c086 | 3443 | if (!folio_trylock(folio)) |
fbe37501 ZY |
3444 | goto next; |
3445 | ||
9ee2c086 | 3446 | if (!split_folio(folio)) |
fbe37501 ZY |
3447 | split++; |
3448 | ||
9ee2c086 | 3449 | folio_unlock(folio); |
fbe37501 | 3450 | next: |
9ee2c086 | 3451 | folio_put(folio); |
fbe37501 ZY |
3452 | cond_resched(); |
3453 | } | |
3454 | ||
3455 | filp_close(candidate, NULL); | |
3456 | ret = 0; | |
3457 | ||
3458 | pr_debug("%lu of %lu file-backed THP split\n", split, total); | |
3459 | out: | |
3460 | putname(file); | |
3461 | return ret; | |
3462 | } | |
3463 | ||
fa6c0231 ZY |
3464 | #define MAX_INPUT_BUF_SZ 255 |
3465 | ||
3466 | static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, | |
3467 | size_t count, loff_t *ppops) | |
3468 | { | |
3469 | static DEFINE_MUTEX(split_debug_mutex); | |
3470 | ssize_t ret; | |
fbe37501 ZY |
3471 | /* hold pid, start_vaddr, end_vaddr or file_path, off_start, off_end */ |
3472 | char input_buf[MAX_INPUT_BUF_SZ]; | |
fa6c0231 ZY |
3473 | int pid; |
3474 | unsigned long vaddr_start, vaddr_end; | |
3475 | ||
3476 | ret = mutex_lock_interruptible(&split_debug_mutex); | |
3477 | if (ret) | |
3478 | return ret; | |
3479 | ||
3480 | ret = -EFAULT; | |
3481 | ||
3482 | memset(input_buf, 0, MAX_INPUT_BUF_SZ); | |
3483 | if (copy_from_user(input_buf, buf, min_t(size_t, count, MAX_INPUT_BUF_SZ))) | |
3484 | goto out; | |
3485 | ||
3486 | input_buf[MAX_INPUT_BUF_SZ - 1] = '\0'; | |
fbe37501 ZY |
3487 | |
3488 | if (input_buf[0] == '/') { | |
3489 | char *tok; | |
3490 | char *buf = input_buf; | |
3491 | char file_path[MAX_INPUT_BUF_SZ]; | |
3492 | pgoff_t off_start = 0, off_end = 0; | |
3493 | size_t input_len = strlen(input_buf); | |
3494 | ||
3495 | tok = strsep(&buf, ","); | |
3496 | if (tok) { | |
1212e00c | 3497 | strcpy(file_path, tok); |
fbe37501 ZY |
3498 | } else { |
3499 | ret = -EINVAL; | |
3500 | goto out; | |
3501 | } | |
3502 | ||
3503 | ret = sscanf(buf, "0x%lx,0x%lx", &off_start, &off_end); | |
3504 | if (ret != 2) { | |
3505 | ret = -EINVAL; | |
3506 | goto out; | |
3507 | } | |
3508 | ret = split_huge_pages_in_file(file_path, off_start, off_end); | |
3509 | if (!ret) | |
3510 | ret = input_len; | |
3511 | ||
3512 | goto out; | |
3513 | } | |
3514 | ||
fa6c0231 ZY |
3515 | ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); |
3516 | if (ret == 1 && pid == 1) { | |
3517 | split_huge_pages_all(); | |
3518 | ret = strlen(input_buf); | |
3519 | goto out; | |
3520 | } else if (ret != 3) { | |
3521 | ret = -EINVAL; | |
3522 | goto out; | |
3523 | } | |
3524 | ||
3525 | ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end); | |
3526 | if (!ret) | |
3527 | ret = strlen(input_buf); | |
3528 | out: | |
3529 | mutex_unlock(&split_debug_mutex); | |
3530 | return ret; | |
3531 | ||
3532 | } | |
3533 | ||
3534 | static const struct file_operations split_huge_pages_fops = { | |
3535 | .owner = THIS_MODULE, | |
3536 | .write = split_huge_pages_write, | |
3537 | .llseek = no_llseek, | |
3538 | }; | |
49071d43 KS |
3539 | |
3540 | static int __init split_huge_pages_debugfs(void) | |
3541 | { | |
d9f7979c GKH |
3542 | debugfs_create_file("split_huge_pages", 0200, NULL, NULL, |
3543 | &split_huge_pages_fops); | |
49071d43 KS |
3544 | return 0; |
3545 | } | |
3546 | late_initcall(split_huge_pages_debugfs); | |
3547 | #endif | |
616b8371 ZY |
3548 | |
3549 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
7f5abe60 | 3550 | int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, |
616b8371 ZY |
3551 | struct page *page) |
3552 | { | |
a8e61d58 | 3553 | struct folio *folio = page_folio(page); |
616b8371 ZY |
3554 | struct vm_area_struct *vma = pvmw->vma; |
3555 | struct mm_struct *mm = vma->vm_mm; | |
3556 | unsigned long address = pvmw->address; | |
6c287605 | 3557 | bool anon_exclusive; |
616b8371 ZY |
3558 | pmd_t pmdval; |
3559 | swp_entry_t entry; | |
ab6e3d09 | 3560 | pmd_t pmdswp; |
616b8371 ZY |
3561 | |
3562 | if (!(pvmw->pmd && !pvmw->pte)) | |
7f5abe60 | 3563 | return 0; |
616b8371 | 3564 | |
616b8371 | 3565 | flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); |
8a8683ad | 3566 | pmdval = pmdp_invalidate(vma, address, pvmw->pmd); |
6c287605 | 3567 | |
e3b4b137 | 3568 | /* See folio_try_share_anon_rmap_pmd(): invalidate PMD first. */ |
a8e61d58 | 3569 | anon_exclusive = folio_test_anon(folio) && PageAnonExclusive(page); |
e3b4b137 | 3570 | if (anon_exclusive && folio_try_share_anon_rmap_pmd(folio, page)) { |
6c287605 | 3571 | set_pmd_at(mm, address, pvmw->pmd, pmdval); |
7f5abe60 | 3572 | return -EBUSY; |
6c287605 DH |
3573 | } |
3574 | ||
616b8371 | 3575 | if (pmd_dirty(pmdval)) |
db44c658 | 3576 | folio_mark_dirty(folio); |
4dd845b5 AP |
3577 | if (pmd_write(pmdval)) |
3578 | entry = make_writable_migration_entry(page_to_pfn(page)); | |
6c287605 DH |
3579 | else if (anon_exclusive) |
3580 | entry = make_readable_exclusive_migration_entry(page_to_pfn(page)); | |
4dd845b5 AP |
3581 | else |
3582 | entry = make_readable_migration_entry(page_to_pfn(page)); | |
2e346877 PX |
3583 | if (pmd_young(pmdval)) |
3584 | entry = make_migration_entry_young(entry); | |
3585 | if (pmd_dirty(pmdval)) | |
3586 | entry = make_migration_entry_dirty(entry); | |
ab6e3d09 NH |
3587 | pmdswp = swp_entry_to_pmd(entry); |
3588 | if (pmd_soft_dirty(pmdval)) | |
3589 | pmdswp = pmd_swp_mksoft_dirty(pmdswp); | |
24bf08c4 DH |
3590 | if (pmd_uffd_wp(pmdval)) |
3591 | pmdswp = pmd_swp_mkuffd_wp(pmdswp); | |
ab6e3d09 | 3592 | set_pmd_at(mm, address, pvmw->pmd, pmdswp); |
a8e61d58 DH |
3593 | folio_remove_rmap_pmd(folio, page, vma); |
3594 | folio_put(folio); | |
283fd6fe | 3595 | trace_set_migration_pmd(address, pmd_val(pmdswp)); |
7f5abe60 DH |
3596 | |
3597 | return 0; | |
616b8371 ZY |
3598 | } |
3599 | ||
3600 | void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) | |
3601 | { | |
14d85a6e | 3602 | struct folio *folio = page_folio(new); |
616b8371 ZY |
3603 | struct vm_area_struct *vma = pvmw->vma; |
3604 | struct mm_struct *mm = vma->vm_mm; | |
3605 | unsigned long address = pvmw->address; | |
4fba8f2a | 3606 | unsigned long haddr = address & HPAGE_PMD_MASK; |
616b8371 ZY |
3607 | pmd_t pmde; |
3608 | swp_entry_t entry; | |
3609 | ||
3610 | if (!(pvmw->pmd && !pvmw->pte)) | |
3611 | return; | |
3612 | ||
3613 | entry = pmd_to_swp_entry(*pvmw->pmd); | |
14d85a6e | 3614 | folio_get(folio); |
2e346877 | 3615 | pmde = mk_huge_pmd(new, READ_ONCE(vma->vm_page_prot)); |
ab6e3d09 NH |
3616 | if (pmd_swp_soft_dirty(*pvmw->pmd)) |
3617 | pmde = pmd_mksoft_dirty(pmde); | |
3c811f78 | 3618 | if (is_writable_migration_entry(entry)) |
161e393c | 3619 | pmde = pmd_mkwrite(pmde, vma); |
8f34f1ea | 3620 | if (pmd_swp_uffd_wp(*pvmw->pmd)) |
f1eb1bac | 3621 | pmde = pmd_mkuffd_wp(pmde); |
2e346877 PX |
3622 | if (!is_migration_entry_young(entry)) |
3623 | pmde = pmd_mkold(pmde); | |
3624 | /* NOTE: this may contain setting soft-dirty on some archs */ | |
14d85a6e | 3625 | if (folio_test_dirty(folio) && is_migration_entry_dirty(entry)) |
2e346877 | 3626 | pmde = pmd_mkdirty(pmde); |
616b8371 | 3627 | |
14d85a6e | 3628 | if (folio_test_anon(folio)) { |
395db7b1 | 3629 | rmap_t rmap_flags = RMAP_NONE; |
6c287605 DH |
3630 | |
3631 | if (!is_readable_migration_entry(entry)) | |
3632 | rmap_flags |= RMAP_EXCLUSIVE; | |
3633 | ||
395db7b1 | 3634 | folio_add_anon_rmap_pmd(folio, new, vma, haddr, rmap_flags); |
6c287605 | 3635 | } else { |
14d85a6e | 3636 | folio_add_file_rmap_pmd(folio, new, vma); |
6c287605 | 3637 | } |
14d85a6e | 3638 | VM_BUG_ON(pmd_write(pmde) && folio_test_anon(folio) && !PageAnonExclusive(new)); |
4fba8f2a | 3639 | set_pmd_at(mm, haddr, pvmw->pmd, pmde); |
5cbcf225 MS |
3640 | |
3641 | /* No need to invalidate - it was non-present before */ | |
616b8371 | 3642 | update_mmu_cache_pmd(vma, address, pvmw->pmd); |
283fd6fe | 3643 | trace_remove_migration_pmd(address, pmd_val(pmde)); |
616b8371 ZY |
3644 | } |
3645 | #endif |