Commit | Line | Data |
---|---|---|
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> |
97ae1749 | 40 | |
71e3aac0 AA |
41 | #include <asm/tlb.h> |
42 | #include <asm/pgalloc.h> | |
43 | #include "internal.h" | |
014bb1de | 44 | #include "swap.h" |
71e3aac0 | 45 | |
283fd6fe AK |
46 | #define CREATE_TRACE_POINTS |
47 | #include <trace/events/thp.h> | |
48 | ||
ba76149f | 49 | /* |
b14d595a MD |
50 | * By default, transparent hugepage support is disabled in order to avoid |
51 | * risking an increased memory footprint for applications that are not | |
52 | * guaranteed to benefit from it. When transparent hugepage support is | |
53 | * enabled, it is for all mappings, and khugepaged scans all mappings. | |
8bfa3f9a JW |
54 | * Defrag is invoked by khugepaged hugepage allocations and by page faults |
55 | * for all hugepage allocations. | |
ba76149f | 56 | */ |
71e3aac0 | 57 | unsigned long transparent_hugepage_flags __read_mostly = |
13ece886 | 58 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS |
ba76149f | 59 | (1<<TRANSPARENT_HUGEPAGE_FLAG)| |
13ece886 AA |
60 | #endif |
61 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE | |
62 | (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)| | |
63 | #endif | |
444eb2a4 | 64 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)| |
79da5407 KS |
65 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)| |
66 | (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); | |
ba76149f | 67 | |
54d91729 QZ |
68 | static struct shrinker *deferred_split_shrinker; |
69 | static unsigned long deferred_split_count(struct shrinker *shrink, | |
70 | struct shrink_control *sc); | |
71 | static unsigned long deferred_split_scan(struct shrinker *shrink, | |
72 | struct shrink_control *sc); | |
f000565a | 73 | |
97ae1749 | 74 | static atomic_t huge_zero_refcount; |
56873f43 | 75 | struct page *huge_zero_page __read_mostly; |
3b77e8c8 | 76 | unsigned long huge_zero_pfn __read_mostly = ~0UL; |
3485b883 RR |
77 | unsigned long huge_anon_orders_always __read_mostly; |
78 | unsigned long huge_anon_orders_madvise __read_mostly; | |
79 | unsigned long huge_anon_orders_inherit __read_mostly; | |
80 | ||
81 | unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, | |
82 | unsigned long vm_flags, bool smaps, | |
83 | bool in_pf, bool enforce_sysfs, | |
84 | unsigned long orders) | |
85 | { | |
86 | /* Check the intersection of requested and supported orders. */ | |
87 | orders &= vma_is_anonymous(vma) ? | |
88 | THP_ORDERS_ALL_ANON : THP_ORDERS_ALL_FILE; | |
89 | if (!orders) | |
90 | return 0; | |
4a6c1297 | 91 | |
9fec5168 | 92 | if (!vma->vm_mm) /* vdso */ |
3485b883 | 93 | return 0; |
9fec5168 | 94 | |
7da4e2cb YS |
95 | /* |
96 | * Explicitly disabled through madvise or prctl, or some | |
97 | * architectures may disable THP for some mappings, for | |
98 | * example, s390 kvm. | |
99 | * */ | |
100 | if ((vm_flags & VM_NOHUGEPAGE) || | |
101 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) | |
3485b883 | 102 | return 0; |
7da4e2cb YS |
103 | /* |
104 | * If the hardware/firmware marked hugepage support disabled. | |
105 | */ | |
3c556d24 | 106 | if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED)) |
3485b883 | 107 | return 0; |
c0630669 | 108 | |
7da4e2cb | 109 | /* khugepaged doesn't collapse DAX vma, but page fault is fine. */ |
9fec5168 | 110 | if (vma_is_dax(vma)) |
3485b883 | 111 | return in_pf ? orders : 0; |
7da4e2cb YS |
112 | |
113 | /* | |
7a81751f | 114 | * khugepaged special VMA and hugetlb VMA. |
7da4e2cb YS |
115 | * Must be checked after dax since some dax mappings may have |
116 | * VM_MIXEDMAP set. | |
117 | */ | |
7a81751f | 118 | if (!in_pf && !smaps && (vm_flags & VM_NO_KHUGEPAGED)) |
3485b883 | 119 | return 0; |
9fec5168 | 120 | |
7da4e2cb | 121 | /* |
3485b883 RR |
122 | * Check alignment for file vma and size for both file and anon vma by |
123 | * filtering out the unsuitable orders. | |
7da4e2cb YS |
124 | * |
125 | * Skip the check for page fault. Huge fault does the check in fault | |
3485b883 | 126 | * handlers. |
7da4e2cb | 127 | */ |
3485b883 RR |
128 | if (!in_pf) { |
129 | int order = highest_order(orders); | |
130 | unsigned long addr; | |
131 | ||
132 | while (orders) { | |
133 | addr = vma->vm_end - (PAGE_SIZE << order); | |
134 | if (thp_vma_suitable_order(vma, addr, order)) | |
135 | break; | |
136 | order = next_order(&orders, order); | |
137 | } | |
138 | ||
139 | if (!orders) | |
140 | return 0; | |
141 | } | |
9fec5168 | 142 | |
7da4e2cb YS |
143 | /* |
144 | * Enabled via shmem mount options or sysfs settings. | |
145 | * Must be done before hugepage flags check since shmem has its | |
146 | * own flags. | |
147 | */ | |
148 | if (!in_pf && shmem_file(vma->vm_file)) | |
2cf13384 | 149 | return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff, |
3485b883 RR |
150 | !enforce_sysfs, vma->vm_mm, vm_flags) |
151 | ? orders : 0; | |
9fec5168 | 152 | |
7a81751f | 153 | if (!vma_is_anonymous(vma)) { |
3485b883 RR |
154 | /* |
155 | * Enforce sysfs THP requirements as necessary. Anonymous vmas | |
156 | * were already handled in thp_vma_allowable_orders(). | |
157 | */ | |
158 | if (enforce_sysfs && | |
159 | (!hugepage_global_enabled() || (!(vm_flags & VM_HUGEPAGE) && | |
160 | !hugepage_global_always()))) | |
161 | return 0; | |
162 | ||
7a81751f ZK |
163 | /* |
164 | * Trust that ->huge_fault() handlers know what they are doing | |
165 | * in fault path. | |
166 | */ | |
167 | if (((in_pf || smaps)) && vma->vm_ops->huge_fault) | |
3485b883 | 168 | return orders; |
7a81751f ZK |
169 | /* Only regular file is valid in collapse path */ |
170 | if (((!in_pf || smaps)) && file_thp_enabled(vma)) | |
3485b883 RR |
171 | return orders; |
172 | return 0; | |
7a81751f | 173 | } |
9fec5168 YS |
174 | |
175 | if (vma_is_temporary_stack(vma)) | |
3485b883 | 176 | return 0; |
9fec5168 YS |
177 | |
178 | /* | |
179 | * THPeligible bit of smaps should show 1 for proper VMAs even | |
180 | * though anon_vma is not initialized yet. | |
7da4e2cb YS |
181 | * |
182 | * Allow page fault since anon_vma may be not initialized until | |
183 | * the first page fault. | |
9fec5168 YS |
184 | */ |
185 | if (!vma->anon_vma) | |
3485b883 | 186 | return (smaps || in_pf) ? orders : 0; |
9fec5168 | 187 | |
3485b883 | 188 | return orders; |
7635d9cb MH |
189 | } |
190 | ||
aaa9705b | 191 | static bool get_huge_zero_page(void) |
97ae1749 KS |
192 | { |
193 | struct page *zero_page; | |
194 | retry: | |
195 | if (likely(atomic_inc_not_zero(&huge_zero_refcount))) | |
aaa9705b | 196 | return true; |
97ae1749 KS |
197 | |
198 | zero_page = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE, | |
4a6c1297 | 199 | HPAGE_PMD_ORDER); |
d8a8e1f0 KS |
200 | if (!zero_page) { |
201 | count_vm_event(THP_ZERO_PAGE_ALLOC_FAILED); | |
aaa9705b | 202 | return false; |
d8a8e1f0 | 203 | } |
97ae1749 | 204 | preempt_disable(); |
5918d10a | 205 | if (cmpxchg(&huge_zero_page, NULL, zero_page)) { |
97ae1749 | 206 | preempt_enable(); |
5ddacbe9 | 207 | __free_pages(zero_page, compound_order(zero_page)); |
97ae1749 KS |
208 | goto retry; |
209 | } | |
3b77e8c8 | 210 | WRITE_ONCE(huge_zero_pfn, page_to_pfn(zero_page)); |
97ae1749 KS |
211 | |
212 | /* We take additional reference here. It will be put back by shrinker */ | |
213 | atomic_set(&huge_zero_refcount, 2); | |
214 | preempt_enable(); | |
f4981502 | 215 | count_vm_event(THP_ZERO_PAGE_ALLOC); |
aaa9705b | 216 | return true; |
4a6c1297 KS |
217 | } |
218 | ||
6fcb52a5 | 219 | static void put_huge_zero_page(void) |
4a6c1297 | 220 | { |
97ae1749 KS |
221 | /* |
222 | * Counter should never go to zero here. Only shrinker can put | |
223 | * last reference. | |
224 | */ | |
225 | BUG_ON(atomic_dec_and_test(&huge_zero_refcount)); | |
4a6c1297 KS |
226 | } |
227 | ||
6fcb52a5 AL |
228 | struct page *mm_get_huge_zero_page(struct mm_struct *mm) |
229 | { | |
230 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
231 | return READ_ONCE(huge_zero_page); | |
232 | ||
233 | if (!get_huge_zero_page()) | |
234 | return NULL; | |
235 | ||
236 | if (test_and_set_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
237 | put_huge_zero_page(); | |
238 | ||
239 | return READ_ONCE(huge_zero_page); | |
240 | } | |
241 | ||
242 | void mm_put_huge_zero_page(struct mm_struct *mm) | |
243 | { | |
244 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) | |
245 | put_huge_zero_page(); | |
246 | } | |
247 | ||
48896466 GC |
248 | static unsigned long shrink_huge_zero_page_count(struct shrinker *shrink, |
249 | struct shrink_control *sc) | |
4a6c1297 | 250 | { |
48896466 GC |
251 | /* we can free zero page only if last reference remains */ |
252 | return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0; | |
253 | } | |
97ae1749 | 254 | |
48896466 GC |
255 | static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink, |
256 | struct shrink_control *sc) | |
257 | { | |
97ae1749 | 258 | if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) { |
5918d10a KS |
259 | struct page *zero_page = xchg(&huge_zero_page, NULL); |
260 | BUG_ON(zero_page == NULL); | |
3b77e8c8 | 261 | WRITE_ONCE(huge_zero_pfn, ~0UL); |
5ddacbe9 | 262 | __free_pages(zero_page, compound_order(zero_page)); |
48896466 | 263 | return HPAGE_PMD_NR; |
97ae1749 KS |
264 | } |
265 | ||
266 | return 0; | |
4a6c1297 KS |
267 | } |
268 | ||
54d91729 | 269 | static struct shrinker *huge_zero_page_shrinker; |
97ae1749 | 270 | |
71e3aac0 | 271 | #ifdef CONFIG_SYSFS |
71e3aac0 AA |
272 | static ssize_t enabled_show(struct kobject *kobj, |
273 | struct kobj_attribute *attr, char *buf) | |
274 | { | |
bfb0ffeb JP |
275 | const char *output; |
276 | ||
444eb2a4 | 277 | if (test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags)) |
bfb0ffeb JP |
278 | output = "[always] madvise never"; |
279 | else if (test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
280 | &transparent_hugepage_flags)) | |
281 | output = "always [madvise] never"; | |
444eb2a4 | 282 | else |
bfb0ffeb JP |
283 | output = "always madvise [never]"; |
284 | ||
285 | return sysfs_emit(buf, "%s\n", output); | |
71e3aac0 | 286 | } |
444eb2a4 | 287 | |
71e3aac0 AA |
288 | static ssize_t enabled_store(struct kobject *kobj, |
289 | struct kobj_attribute *attr, | |
290 | const char *buf, size_t count) | |
291 | { | |
21440d7e | 292 | ssize_t ret = count; |
ba76149f | 293 | |
f42f2552 | 294 | if (sysfs_streq(buf, "always")) { |
21440d7e DR |
295 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); |
296 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 297 | } else if (sysfs_streq(buf, "madvise")) { |
21440d7e DR |
298 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
299 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 300 | } else if (sysfs_streq(buf, "never")) { |
21440d7e DR |
301 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
302 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
303 | } else | |
304 | ret = -EINVAL; | |
ba76149f AA |
305 | |
306 | if (ret > 0) { | |
b46e756f | 307 | int err = start_stop_khugepaged(); |
ba76149f AA |
308 | if (err) |
309 | ret = err; | |
310 | } | |
ba76149f | 311 | return ret; |
71e3aac0 | 312 | } |
37139bb0 ML |
313 | |
314 | static struct kobj_attribute enabled_attr = __ATTR_RW(enabled); | |
71e3aac0 | 315 | |
b46e756f | 316 | ssize_t single_hugepage_flag_show(struct kobject *kobj, |
bfb0ffeb JP |
317 | struct kobj_attribute *attr, char *buf, |
318 | enum transparent_hugepage_flag flag) | |
71e3aac0 | 319 | { |
bfb0ffeb JP |
320 | return sysfs_emit(buf, "%d\n", |
321 | !!test_bit(flag, &transparent_hugepage_flags)); | |
71e3aac0 | 322 | } |
e27e6151 | 323 | |
b46e756f | 324 | ssize_t single_hugepage_flag_store(struct kobject *kobj, |
71e3aac0 AA |
325 | struct kobj_attribute *attr, |
326 | const char *buf, size_t count, | |
327 | enum transparent_hugepage_flag flag) | |
328 | { | |
e27e6151 BH |
329 | unsigned long value; |
330 | int ret; | |
331 | ||
332 | ret = kstrtoul(buf, 10, &value); | |
333 | if (ret < 0) | |
334 | return ret; | |
335 | if (value > 1) | |
336 | return -EINVAL; | |
337 | ||
338 | if (value) | |
71e3aac0 | 339 | set_bit(flag, &transparent_hugepage_flags); |
e27e6151 | 340 | else |
71e3aac0 | 341 | clear_bit(flag, &transparent_hugepage_flags); |
71e3aac0 AA |
342 | |
343 | return count; | |
344 | } | |
345 | ||
71e3aac0 AA |
346 | static ssize_t defrag_show(struct kobject *kobj, |
347 | struct kobj_attribute *attr, char *buf) | |
348 | { | |
bfb0ffeb JP |
349 | const char *output; |
350 | ||
351 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, | |
352 | &transparent_hugepage_flags)) | |
353 | output = "[always] defer defer+madvise madvise never"; | |
354 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, | |
355 | &transparent_hugepage_flags)) | |
356 | output = "always [defer] defer+madvise madvise never"; | |
357 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, | |
358 | &transparent_hugepage_flags)) | |
359 | output = "always defer [defer+madvise] madvise never"; | |
360 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, | |
361 | &transparent_hugepage_flags)) | |
362 | output = "always defer defer+madvise [madvise] never"; | |
363 | else | |
364 | output = "always defer defer+madvise madvise [never]"; | |
365 | ||
366 | return sysfs_emit(buf, "%s\n", output); | |
71e3aac0 | 367 | } |
21440d7e | 368 | |
71e3aac0 AA |
369 | static ssize_t defrag_store(struct kobject *kobj, |
370 | struct kobj_attribute *attr, | |
371 | const char *buf, size_t count) | |
372 | { | |
f42f2552 | 373 | if (sysfs_streq(buf, "always")) { |
21440d7e DR |
374 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
375 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
376 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
377 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 378 | } else if (sysfs_streq(buf, "defer+madvise")) { |
21440d7e DR |
379 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
380 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
381 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
382 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 383 | } else if (sysfs_streq(buf, "defer")) { |
4fad7fb6 DR |
384 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
385 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
386 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
387 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 388 | } else if (sysfs_streq(buf, "madvise")) { |
21440d7e DR |
389 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
390 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
391 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
392 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
f42f2552 | 393 | } else if (sysfs_streq(buf, "never")) { |
21440d7e DR |
394 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
395 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); | |
396 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); | |
397 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); | |
398 | } else | |
399 | return -EINVAL; | |
400 | ||
401 | return count; | |
71e3aac0 | 402 | } |
37139bb0 | 403 | static struct kobj_attribute defrag_attr = __ATTR_RW(defrag); |
71e3aac0 | 404 | |
79da5407 | 405 | static ssize_t use_zero_page_show(struct kobject *kobj, |
ae7a927d | 406 | struct kobj_attribute *attr, char *buf) |
79da5407 | 407 | { |
b46e756f | 408 | return single_hugepage_flag_show(kobj, attr, buf, |
ae7a927d | 409 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
79da5407 KS |
410 | } |
411 | static ssize_t use_zero_page_store(struct kobject *kobj, | |
412 | struct kobj_attribute *attr, const char *buf, size_t count) | |
413 | { | |
b46e756f | 414 | return single_hugepage_flag_store(kobj, attr, buf, count, |
79da5407 KS |
415 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
416 | } | |
37139bb0 | 417 | static struct kobj_attribute use_zero_page_attr = __ATTR_RW(use_zero_page); |
49920d28 HD |
418 | |
419 | static ssize_t hpage_pmd_size_show(struct kobject *kobj, | |
ae7a927d | 420 | struct kobj_attribute *attr, char *buf) |
49920d28 | 421 | { |
ae7a927d | 422 | return sysfs_emit(buf, "%lu\n", HPAGE_PMD_SIZE); |
49920d28 HD |
423 | } |
424 | static struct kobj_attribute hpage_pmd_size_attr = | |
425 | __ATTR_RO(hpage_pmd_size); | |
426 | ||
71e3aac0 AA |
427 | static struct attribute *hugepage_attr[] = { |
428 | &enabled_attr.attr, | |
429 | &defrag_attr.attr, | |
79da5407 | 430 | &use_zero_page_attr.attr, |
49920d28 | 431 | &hpage_pmd_size_attr.attr, |
396bcc52 | 432 | #ifdef CONFIG_SHMEM |
5a6e75f8 | 433 | &shmem_enabled_attr.attr, |
71e3aac0 AA |
434 | #endif |
435 | NULL, | |
436 | }; | |
437 | ||
8aa95a21 | 438 | static const struct attribute_group hugepage_attr_group = { |
71e3aac0 | 439 | .attrs = hugepage_attr, |
ba76149f AA |
440 | }; |
441 | ||
3485b883 RR |
442 | static void hugepage_exit_sysfs(struct kobject *hugepage_kobj); |
443 | static void thpsize_release(struct kobject *kobj); | |
444 | static DEFINE_SPINLOCK(huge_anon_orders_lock); | |
445 | static LIST_HEAD(thpsize_list); | |
446 | ||
447 | struct thpsize { | |
448 | struct kobject kobj; | |
449 | struct list_head node; | |
450 | int order; | |
451 | }; | |
452 | ||
453 | #define to_thpsize(kobj) container_of(kobj, struct thpsize, kobj) | |
454 | ||
455 | static ssize_t thpsize_enabled_show(struct kobject *kobj, | |
456 | struct kobj_attribute *attr, char *buf) | |
457 | { | |
458 | int order = to_thpsize(kobj)->order; | |
459 | const char *output; | |
460 | ||
461 | if (test_bit(order, &huge_anon_orders_always)) | |
462 | output = "[always] inherit madvise never"; | |
463 | else if (test_bit(order, &huge_anon_orders_inherit)) | |
464 | output = "always [inherit] madvise never"; | |
465 | else if (test_bit(order, &huge_anon_orders_madvise)) | |
466 | output = "always inherit [madvise] never"; | |
467 | else | |
468 | output = "always inherit madvise [never]"; | |
469 | ||
470 | return sysfs_emit(buf, "%s\n", output); | |
471 | } | |
472 | ||
473 | static ssize_t thpsize_enabled_store(struct kobject *kobj, | |
474 | struct kobj_attribute *attr, | |
475 | const char *buf, size_t count) | |
476 | { | |
477 | int order = to_thpsize(kobj)->order; | |
478 | ssize_t ret = count; | |
479 | ||
480 | if (sysfs_streq(buf, "always")) { | |
481 | spin_lock(&huge_anon_orders_lock); | |
482 | clear_bit(order, &huge_anon_orders_inherit); | |
483 | clear_bit(order, &huge_anon_orders_madvise); | |
484 | set_bit(order, &huge_anon_orders_always); | |
485 | spin_unlock(&huge_anon_orders_lock); | |
486 | } else if (sysfs_streq(buf, "inherit")) { | |
487 | spin_lock(&huge_anon_orders_lock); | |
488 | clear_bit(order, &huge_anon_orders_always); | |
489 | clear_bit(order, &huge_anon_orders_madvise); | |
490 | set_bit(order, &huge_anon_orders_inherit); | |
491 | spin_unlock(&huge_anon_orders_lock); | |
492 | } else if (sysfs_streq(buf, "madvise")) { | |
493 | spin_lock(&huge_anon_orders_lock); | |
494 | clear_bit(order, &huge_anon_orders_always); | |
495 | clear_bit(order, &huge_anon_orders_inherit); | |
496 | set_bit(order, &huge_anon_orders_madvise); | |
497 | spin_unlock(&huge_anon_orders_lock); | |
498 | } else if (sysfs_streq(buf, "never")) { | |
499 | spin_lock(&huge_anon_orders_lock); | |
500 | clear_bit(order, &huge_anon_orders_always); | |
501 | clear_bit(order, &huge_anon_orders_inherit); | |
502 | clear_bit(order, &huge_anon_orders_madvise); | |
503 | spin_unlock(&huge_anon_orders_lock); | |
504 | } else | |
505 | ret = -EINVAL; | |
506 | ||
507 | return ret; | |
508 | } | |
509 | ||
510 | static struct kobj_attribute thpsize_enabled_attr = | |
511 | __ATTR(enabled, 0644, thpsize_enabled_show, thpsize_enabled_store); | |
512 | ||
513 | static struct attribute *thpsize_attrs[] = { | |
514 | &thpsize_enabled_attr.attr, | |
515 | NULL, | |
516 | }; | |
517 | ||
518 | static const struct attribute_group thpsize_attr_group = { | |
519 | .attrs = thpsize_attrs, | |
520 | }; | |
521 | ||
522 | static const struct kobj_type thpsize_ktype = { | |
523 | .release = &thpsize_release, | |
524 | .sysfs_ops = &kobj_sysfs_ops, | |
525 | }; | |
526 | ||
527 | static struct thpsize *thpsize_create(int order, struct kobject *parent) | |
528 | { | |
529 | unsigned long size = (PAGE_SIZE << order) / SZ_1K; | |
530 | struct thpsize *thpsize; | |
531 | int ret; | |
532 | ||
533 | thpsize = kzalloc(sizeof(*thpsize), GFP_KERNEL); | |
534 | if (!thpsize) | |
535 | return ERR_PTR(-ENOMEM); | |
536 | ||
537 | ret = kobject_init_and_add(&thpsize->kobj, &thpsize_ktype, parent, | |
538 | "hugepages-%lukB", size); | |
539 | if (ret) { | |
540 | kfree(thpsize); | |
541 | return ERR_PTR(ret); | |
542 | } | |
543 | ||
544 | ret = sysfs_create_group(&thpsize->kobj, &thpsize_attr_group); | |
545 | if (ret) { | |
546 | kobject_put(&thpsize->kobj); | |
547 | return ERR_PTR(ret); | |
548 | } | |
549 | ||
550 | thpsize->order = order; | |
551 | return thpsize; | |
552 | } | |
553 | ||
554 | static void thpsize_release(struct kobject *kobj) | |
555 | { | |
556 | kfree(to_thpsize(kobj)); | |
557 | } | |
558 | ||
569e5590 | 559 | static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) |
71e3aac0 | 560 | { |
71e3aac0 | 561 | int err; |
3485b883 RR |
562 | struct thpsize *thpsize; |
563 | unsigned long orders; | |
564 | int order; | |
565 | ||
566 | /* | |
567 | * Default to setting PMD-sized THP to inherit the global setting and | |
568 | * disable all other sizes. powerpc's PMD_ORDER isn't a compile-time | |
569 | * constant so we have to do this here. | |
570 | */ | |
571 | huge_anon_orders_inherit = BIT(PMD_ORDER); | |
71e3aac0 | 572 | |
569e5590 SL |
573 | *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj); |
574 | if (unlikely(!*hugepage_kobj)) { | |
ae3a8c1c | 575 | pr_err("failed to create transparent hugepage kobject\n"); |
569e5590 | 576 | return -ENOMEM; |
ba76149f AA |
577 | } |
578 | ||
569e5590 | 579 | err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group); |
ba76149f | 580 | if (err) { |
ae3a8c1c | 581 | pr_err("failed to register transparent hugepage group\n"); |
569e5590 | 582 | goto delete_obj; |
ba76149f AA |
583 | } |
584 | ||
569e5590 | 585 | err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group); |
ba76149f | 586 | if (err) { |
ae3a8c1c | 587 | pr_err("failed to register transparent hugepage group\n"); |
569e5590 | 588 | goto remove_hp_group; |
ba76149f | 589 | } |
569e5590 | 590 | |
3485b883 RR |
591 | orders = THP_ORDERS_ALL_ANON; |
592 | order = highest_order(orders); | |
593 | while (orders) { | |
594 | thpsize = thpsize_create(order, *hugepage_kobj); | |
595 | if (IS_ERR(thpsize)) { | |
596 | pr_err("failed to create thpsize for order %d\n", order); | |
597 | err = PTR_ERR(thpsize); | |
598 | goto remove_all; | |
599 | } | |
600 | list_add(&thpsize->node, &thpsize_list); | |
601 | order = next_order(&orders, order); | |
602 | } | |
603 | ||
569e5590 SL |
604 | return 0; |
605 | ||
3485b883 RR |
606 | remove_all: |
607 | hugepage_exit_sysfs(*hugepage_kobj); | |
608 | return err; | |
569e5590 SL |
609 | remove_hp_group: |
610 | sysfs_remove_group(*hugepage_kobj, &hugepage_attr_group); | |
611 | delete_obj: | |
612 | kobject_put(*hugepage_kobj); | |
613 | return err; | |
614 | } | |
615 | ||
616 | static void __init hugepage_exit_sysfs(struct kobject *hugepage_kobj) | |
617 | { | |
3485b883 RR |
618 | struct thpsize *thpsize, *tmp; |
619 | ||
620 | list_for_each_entry_safe(thpsize, tmp, &thpsize_list, node) { | |
621 | list_del(&thpsize->node); | |
622 | kobject_put(&thpsize->kobj); | |
623 | } | |
624 | ||
569e5590 SL |
625 | sysfs_remove_group(hugepage_kobj, &khugepaged_attr_group); |
626 | sysfs_remove_group(hugepage_kobj, &hugepage_attr_group); | |
627 | kobject_put(hugepage_kobj); | |
628 | } | |
629 | #else | |
630 | static inline int hugepage_init_sysfs(struct kobject **hugepage_kobj) | |
631 | { | |
632 | return 0; | |
633 | } | |
634 | ||
635 | static inline void hugepage_exit_sysfs(struct kobject *hugepage_kobj) | |
636 | { | |
637 | } | |
638 | #endif /* CONFIG_SYSFS */ | |
639 | ||
54d91729 QZ |
640 | static int __init thp_shrinker_init(void) |
641 | { | |
642 | huge_zero_page_shrinker = shrinker_alloc(0, "thp-zero"); | |
643 | if (!huge_zero_page_shrinker) | |
644 | return -ENOMEM; | |
645 | ||
646 | deferred_split_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE | | |
647 | SHRINKER_MEMCG_AWARE | | |
648 | SHRINKER_NONSLAB, | |
649 | "thp-deferred_split"); | |
650 | if (!deferred_split_shrinker) { | |
651 | shrinker_free(huge_zero_page_shrinker); | |
652 | return -ENOMEM; | |
653 | } | |
654 | ||
655 | huge_zero_page_shrinker->count_objects = shrink_huge_zero_page_count; | |
656 | huge_zero_page_shrinker->scan_objects = shrink_huge_zero_page_scan; | |
657 | shrinker_register(huge_zero_page_shrinker); | |
658 | ||
659 | deferred_split_shrinker->count_objects = deferred_split_count; | |
660 | deferred_split_shrinker->scan_objects = deferred_split_scan; | |
661 | shrinker_register(deferred_split_shrinker); | |
662 | ||
663 | return 0; | |
664 | } | |
665 | ||
666 | static void __init thp_shrinker_exit(void) | |
667 | { | |
668 | shrinker_free(huge_zero_page_shrinker); | |
669 | shrinker_free(deferred_split_shrinker); | |
670 | } | |
671 | ||
569e5590 SL |
672 | static int __init hugepage_init(void) |
673 | { | |
674 | int err; | |
675 | struct kobject *hugepage_kobj; | |
676 | ||
677 | if (!has_transparent_hugepage()) { | |
3c556d24 | 678 | transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED; |
569e5590 SL |
679 | return -EINVAL; |
680 | } | |
681 | ||
ff20c2e0 KS |
682 | /* |
683 | * hugepages can't be allocated by the buddy allocator | |
684 | */ | |
23baf831 | 685 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER > MAX_ORDER); |
ff20c2e0 KS |
686 | /* |
687 | * we use page->mapping and page->index in second tail page | |
688 | * as list_head: assuming THP order >= 2 | |
689 | */ | |
690 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER < 2); | |
691 | ||
569e5590 SL |
692 | err = hugepage_init_sysfs(&hugepage_kobj); |
693 | if (err) | |
65ebb64f | 694 | goto err_sysfs; |
ba76149f | 695 | |
b46e756f | 696 | err = khugepaged_init(); |
ba76149f | 697 | if (err) |
65ebb64f | 698 | goto err_slab; |
ba76149f | 699 | |
54d91729 | 700 | err = thp_shrinker_init(); |
9a982250 | 701 | if (err) |
54d91729 | 702 | goto err_shrinker; |
97ae1749 | 703 | |
97562cd2 RR |
704 | /* |
705 | * By default disable transparent hugepages on smaller systems, | |
706 | * where the extra memory used could hurt more than TLB overhead | |
707 | * is likely to save. The admin can still enable it through /sys. | |
708 | */ | |
ca79b0c2 | 709 | if (totalram_pages() < (512 << (20 - PAGE_SHIFT))) { |
97562cd2 | 710 | transparent_hugepage_flags = 0; |
79553da2 KS |
711 | return 0; |
712 | } | |
97562cd2 | 713 | |
79553da2 | 714 | err = start_stop_khugepaged(); |
65ebb64f KS |
715 | if (err) |
716 | goto err_khugepaged; | |
ba76149f | 717 | |
569e5590 | 718 | return 0; |
65ebb64f | 719 | err_khugepaged: |
54d91729 QZ |
720 | thp_shrinker_exit(); |
721 | err_shrinker: | |
b46e756f | 722 | khugepaged_destroy(); |
65ebb64f | 723 | err_slab: |
569e5590 | 724 | hugepage_exit_sysfs(hugepage_kobj); |
65ebb64f | 725 | err_sysfs: |
ba76149f | 726 | return err; |
71e3aac0 | 727 | } |
a64fb3cd | 728 | subsys_initcall(hugepage_init); |
71e3aac0 AA |
729 | |
730 | static int __init setup_transparent_hugepage(char *str) | |
731 | { | |
732 | int ret = 0; | |
733 | if (!str) | |
734 | goto out; | |
735 | if (!strcmp(str, "always")) { | |
736 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
737 | &transparent_hugepage_flags); | |
738 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
739 | &transparent_hugepage_flags); | |
740 | ret = 1; | |
741 | } else if (!strcmp(str, "madvise")) { | |
742 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
743 | &transparent_hugepage_flags); | |
744 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
745 | &transparent_hugepage_flags); | |
746 | ret = 1; | |
747 | } else if (!strcmp(str, "never")) { | |
748 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, | |
749 | &transparent_hugepage_flags); | |
750 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, | |
751 | &transparent_hugepage_flags); | |
752 | ret = 1; | |
753 | } | |
754 | out: | |
755 | if (!ret) | |
ae3a8c1c | 756 | pr_warn("transparent_hugepage= cannot parse, ignored\n"); |
71e3aac0 AA |
757 | return ret; |
758 | } | |
759 | __setup("transparent_hugepage=", setup_transparent_hugepage); | |
760 | ||
f55e1014 | 761 | pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) |
71e3aac0 | 762 | { |
f55e1014 | 763 | if (likely(vma->vm_flags & VM_WRITE)) |
161e393c | 764 | pmd = pmd_mkwrite(pmd, vma); |
71e3aac0 AA |
765 | return pmd; |
766 | } | |
767 | ||
87eaceb3 | 768 | #ifdef CONFIG_MEMCG |
f8baa6be MWO |
769 | static inline |
770 | struct deferred_split *get_deferred_split_queue(struct folio *folio) | |
9a982250 | 771 | { |
f8baa6be MWO |
772 | struct mem_cgroup *memcg = folio_memcg(folio); |
773 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); | |
87eaceb3 YS |
774 | |
775 | if (memcg) | |
776 | return &memcg->deferred_split_queue; | |
777 | else | |
778 | return &pgdat->deferred_split_queue; | |
9a982250 | 779 | } |
87eaceb3 | 780 | #else |
f8baa6be MWO |
781 | static inline |
782 | struct deferred_split *get_deferred_split_queue(struct folio *folio) | |
87eaceb3 | 783 | { |
f8baa6be | 784 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); |
87eaceb3 YS |
785 | |
786 | return &pgdat->deferred_split_queue; | |
787 | } | |
788 | #endif | |
9a982250 | 789 | |
da6e7bf3 | 790 | void folio_prep_large_rmappable(struct folio *folio) |
9a982250 | 791 | { |
8991de90 MWO |
792 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
793 | INIT_LIST_HEAD(&folio->_deferred_list); | |
de53c05f | 794 | folio_set_large_rmappable(folio); |
9a982250 KS |
795 | } |
796 | ||
a644b0ab | 797 | static inline bool is_transparent_hugepage(struct folio *folio) |
005ba37c | 798 | { |
a644b0ab | 799 | if (!folio_test_large(folio)) |
fa1f68cc | 800 | return false; |
005ba37c | 801 | |
f04029f3 | 802 | return is_huge_zero_page(&folio->page) || |
de53c05f | 803 | folio_test_large_rmappable(folio); |
005ba37c | 804 | } |
005ba37c | 805 | |
97d3d0f9 KS |
806 | static unsigned long __thp_get_unmapped_area(struct file *filp, |
807 | unsigned long addr, unsigned long len, | |
74d2fad1 TK |
808 | loff_t off, unsigned long flags, unsigned long size) |
809 | { | |
74d2fad1 TK |
810 | loff_t off_end = off + len; |
811 | loff_t off_align = round_up(off, size); | |
97d3d0f9 | 812 | unsigned long len_pad, ret; |
74d2fad1 TK |
813 | |
814 | if (off_end <= off_align || (off_end - off_align) < size) | |
815 | return 0; | |
816 | ||
817 | len_pad = len + size; | |
818 | if (len_pad < len || (off + len_pad) < off) | |
819 | return 0; | |
820 | ||
97d3d0f9 | 821 | ret = current->mm->get_unmapped_area(filp, addr, len_pad, |
74d2fad1 | 822 | off >> PAGE_SHIFT, flags); |
97d3d0f9 KS |
823 | |
824 | /* | |
825 | * The failure might be due to length padding. The caller will retry | |
826 | * without the padding. | |
827 | */ | |
828 | if (IS_ERR_VALUE(ret)) | |
74d2fad1 TK |
829 | return 0; |
830 | ||
97d3d0f9 KS |
831 | /* |
832 | * Do not try to align to THP boundary if allocation at the address | |
833 | * hint succeeds. | |
834 | */ | |
835 | if (ret == addr) | |
836 | return addr; | |
837 | ||
838 | ret += (off - ret) & (size - 1); | |
839 | return ret; | |
74d2fad1 TK |
840 | } |
841 | ||
842 | unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, | |
843 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
844 | { | |
97d3d0f9 | 845 | unsigned long ret; |
74d2fad1 TK |
846 | loff_t off = (loff_t)pgoff << PAGE_SHIFT; |
847 | ||
97d3d0f9 KS |
848 | ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE); |
849 | if (ret) | |
850 | return ret; | |
1854bc6e | 851 | |
74d2fad1 TK |
852 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); |
853 | } | |
854 | EXPORT_SYMBOL_GPL(thp_get_unmapped_area); | |
855 | ||
2b740303 SJ |
856 | static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, |
857 | struct page *page, gfp_t gfp) | |
71e3aac0 | 858 | { |
82b0f8c3 | 859 | struct vm_area_struct *vma = vmf->vma; |
cfe3236d | 860 | struct folio *folio = page_folio(page); |
71e3aac0 | 861 | pgtable_t pgtable; |
82b0f8c3 | 862 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
2b740303 | 863 | vm_fault_t ret = 0; |
71e3aac0 | 864 | |
cfe3236d | 865 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
00501b53 | 866 | |
cfe3236d KW |
867 | if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { |
868 | folio_put(folio); | |
6b251fc9 | 869 | count_vm_event(THP_FAULT_FALLBACK); |
85b9f46e | 870 | count_vm_event(THP_FAULT_FALLBACK_CHARGE); |
6b251fc9 AA |
871 | return VM_FAULT_FALLBACK; |
872 | } | |
cfe3236d | 873 | folio_throttle_swaprate(folio, gfp); |
00501b53 | 874 | |
4cf58924 | 875 | pgtable = pte_alloc_one(vma->vm_mm); |
00501b53 | 876 | if (unlikely(!pgtable)) { |
6b31d595 MH |
877 | ret = VM_FAULT_OOM; |
878 | goto release; | |
00501b53 | 879 | } |
71e3aac0 | 880 | |
c79b57e4 | 881 | clear_huge_page(page, vmf->address, HPAGE_PMD_NR); |
52f37629 | 882 | /* |
cfe3236d | 883 | * The memory barrier inside __folio_mark_uptodate makes sure that |
52f37629 MK |
884 | * clear_huge_page writes become visible before the set_pmd_at() |
885 | * write. | |
886 | */ | |
cfe3236d | 887 | __folio_mark_uptodate(folio); |
71e3aac0 | 888 | |
82b0f8c3 JK |
889 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
890 | if (unlikely(!pmd_none(*vmf->pmd))) { | |
6b31d595 | 891 | goto unlock_release; |
71e3aac0 AA |
892 | } else { |
893 | pmd_t entry; | |
6b251fc9 | 894 | |
6b31d595 MH |
895 | ret = check_stable_address_space(vma->vm_mm); |
896 | if (ret) | |
897 | goto unlock_release; | |
898 | ||
6b251fc9 AA |
899 | /* Deliver the page fault to userland */ |
900 | if (userfaultfd_missing(vma)) { | |
82b0f8c3 | 901 | spin_unlock(vmf->ptl); |
cfe3236d | 902 | folio_put(folio); |
bae473a4 | 903 | pte_free(vma->vm_mm, pgtable); |
8fd5eda4 ML |
904 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
905 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); | |
906 | return ret; | |
6b251fc9 AA |
907 | } |
908 | ||
3122359a | 909 | entry = mk_huge_pmd(page, vma->vm_page_prot); |
f55e1014 | 910 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
cfe3236d KW |
911 | folio_add_new_anon_rmap(folio, vma, haddr); |
912 | folio_add_lru_vma(folio, vma); | |
82b0f8c3 JK |
913 | pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); |
914 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); | |
fca40573 | 915 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
bae473a4 | 916 | add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
c4812909 | 917 | mm_inc_nr_ptes(vma->vm_mm); |
82b0f8c3 | 918 | spin_unlock(vmf->ptl); |
6b251fc9 | 919 | count_vm_event(THP_FAULT_ALLOC); |
9d82c694 | 920 | count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); |
71e3aac0 AA |
921 | } |
922 | ||
aa2e878e | 923 | return 0; |
6b31d595 MH |
924 | unlock_release: |
925 | spin_unlock(vmf->ptl); | |
926 | release: | |
927 | if (pgtable) | |
928 | pte_free(vma->vm_mm, pgtable); | |
cfe3236d | 929 | folio_put(folio); |
6b31d595 MH |
930 | return ret; |
931 | ||
71e3aac0 AA |
932 | } |
933 | ||
444eb2a4 | 934 | /* |
21440d7e DR |
935 | * always: directly stall for all thp allocations |
936 | * defer: wake kswapd and fail if not immediately available | |
937 | * defer+madvise: wake kswapd and directly stall for MADV_HUGEPAGE, otherwise | |
938 | * fail if not immediately available | |
939 | * madvise: directly stall for MADV_HUGEPAGE, otherwise fail if not immediately | |
940 | * available | |
941 | * never: never stall for any thp allocation | |
444eb2a4 | 942 | */ |
164cc4fe | 943 | gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma) |
444eb2a4 | 944 | { |
164cc4fe | 945 | const bool vma_madvised = vma && (vma->vm_flags & VM_HUGEPAGE); |
2f0799a0 | 946 | |
ac79f78d | 947 | /* Always do synchronous compaction */ |
a8282608 AA |
948 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags)) |
949 | return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY); | |
ac79f78d DR |
950 | |
951 | /* Kick kcompactd and fail quickly */ | |
21440d7e | 952 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags)) |
19deb769 | 953 | return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM; |
ac79f78d DR |
954 | |
955 | /* Synchronous compaction if madvised, otherwise kick kcompactd */ | |
21440d7e | 956 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags)) |
19deb769 DR |
957 | return GFP_TRANSHUGE_LIGHT | |
958 | (vma_madvised ? __GFP_DIRECT_RECLAIM : | |
959 | __GFP_KSWAPD_RECLAIM); | |
ac79f78d DR |
960 | |
961 | /* Only do synchronous compaction if madvised */ | |
21440d7e | 962 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags)) |
19deb769 DR |
963 | return GFP_TRANSHUGE_LIGHT | |
964 | (vma_madvised ? __GFP_DIRECT_RECLAIM : 0); | |
ac79f78d | 965 | |
19deb769 | 966 | return GFP_TRANSHUGE_LIGHT; |
444eb2a4 MG |
967 | } |
968 | ||
c4088ebd | 969 | /* Caller must hold page table lock. */ |
2efeb8da | 970 | static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm, |
97ae1749 | 971 | struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd, |
5918d10a | 972 | struct page *zero_page) |
fc9fe822 KS |
973 | { |
974 | pmd_t entry; | |
7c414164 | 975 | if (!pmd_none(*pmd)) |
2efeb8da | 976 | return; |
5918d10a | 977 | entry = mk_pmd(zero_page, vma->vm_page_prot); |
fc9fe822 | 978 | entry = pmd_mkhuge(entry); |
c8bb4163 | 979 | pgtable_trans_huge_deposit(mm, pmd, pgtable); |
fc9fe822 | 980 | set_pmd_at(mm, haddr, pmd, entry); |
c4812909 | 981 | mm_inc_nr_ptes(mm); |
fc9fe822 KS |
982 | } |
983 | ||
2b740303 | 984 | vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf) |
71e3aac0 | 985 | { |
82b0f8c3 | 986 | struct vm_area_struct *vma = vmf->vma; |
077fcf11 | 987 | gfp_t gfp; |
cb196ee1 | 988 | struct folio *folio; |
82b0f8c3 | 989 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
71e3aac0 | 990 | |
3485b883 | 991 | if (!thp_vma_suitable_order(vma, haddr, PMD_ORDER)) |
c0292554 | 992 | return VM_FAULT_FALLBACK; |
128ec037 KS |
993 | if (unlikely(anon_vma_prepare(vma))) |
994 | return VM_FAULT_OOM; | |
4fa6893f | 995 | khugepaged_enter_vma(vma, vma->vm_flags); |
d2081b2b | 996 | |
82b0f8c3 | 997 | if (!(vmf->flags & FAULT_FLAG_WRITE) && |
bae473a4 | 998 | !mm_forbids_zeropage(vma->vm_mm) && |
128ec037 KS |
999 | transparent_hugepage_use_zero_page()) { |
1000 | pgtable_t pgtable; | |
1001 | struct page *zero_page; | |
2b740303 | 1002 | vm_fault_t ret; |
4cf58924 | 1003 | pgtable = pte_alloc_one(vma->vm_mm); |
128ec037 | 1004 | if (unlikely(!pgtable)) |
ba76149f | 1005 | return VM_FAULT_OOM; |
6fcb52a5 | 1006 | zero_page = mm_get_huge_zero_page(vma->vm_mm); |
128ec037 | 1007 | if (unlikely(!zero_page)) { |
bae473a4 | 1008 | pte_free(vma->vm_mm, pgtable); |
81ab4201 | 1009 | count_vm_event(THP_FAULT_FALLBACK); |
c0292554 | 1010 | return VM_FAULT_FALLBACK; |
b9bbfbe3 | 1011 | } |
82b0f8c3 | 1012 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
6b251fc9 | 1013 | ret = 0; |
82b0f8c3 | 1014 | if (pmd_none(*vmf->pmd)) { |
6b31d595 MH |
1015 | ret = check_stable_address_space(vma->vm_mm); |
1016 | if (ret) { | |
1017 | spin_unlock(vmf->ptl); | |
bfe8cc1d | 1018 | pte_free(vma->vm_mm, pgtable); |
6b31d595 | 1019 | } else if (userfaultfd_missing(vma)) { |
82b0f8c3 | 1020 | spin_unlock(vmf->ptl); |
bfe8cc1d | 1021 | pte_free(vma->vm_mm, pgtable); |
82b0f8c3 | 1022 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
6b251fc9 AA |
1023 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); |
1024 | } else { | |
bae473a4 | 1025 | set_huge_zero_page(pgtable, vma->vm_mm, vma, |
82b0f8c3 | 1026 | haddr, vmf->pmd, zero_page); |
fca40573 | 1027 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
82b0f8c3 | 1028 | spin_unlock(vmf->ptl); |
6b251fc9 | 1029 | } |
bfe8cc1d | 1030 | } else { |
82b0f8c3 | 1031 | spin_unlock(vmf->ptl); |
bae473a4 | 1032 | pte_free(vma->vm_mm, pgtable); |
bfe8cc1d | 1033 | } |
6b251fc9 | 1034 | return ret; |
71e3aac0 | 1035 | } |
164cc4fe | 1036 | gfp = vma_thp_gfp_mask(vma); |
cb196ee1 MWO |
1037 | folio = vma_alloc_folio(gfp, HPAGE_PMD_ORDER, vma, haddr, true); |
1038 | if (unlikely(!folio)) { | |
128ec037 | 1039 | count_vm_event(THP_FAULT_FALLBACK); |
c0292554 | 1040 | return VM_FAULT_FALLBACK; |
128ec037 | 1041 | } |
cb196ee1 | 1042 | return __do_huge_pmd_anonymous_page(vmf, &folio->page, gfp); |
71e3aac0 AA |
1043 | } |
1044 | ||
ae18d6dc | 1045 | static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, |
3b6521f5 OH |
1046 | pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write, |
1047 | pgtable_t pgtable) | |
5cad465d MW |
1048 | { |
1049 | struct mm_struct *mm = vma->vm_mm; | |
1050 | pmd_t entry; | |
1051 | spinlock_t *ptl; | |
1052 | ||
1053 | ptl = pmd_lock(mm, pmd); | |
c6f3c5ee AK |
1054 | if (!pmd_none(*pmd)) { |
1055 | if (write) { | |
1056 | if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { | |
1057 | WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); | |
1058 | goto out_unlock; | |
1059 | } | |
1060 | entry = pmd_mkyoung(*pmd); | |
1061 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); | |
1062 | if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) | |
1063 | update_mmu_cache_pmd(vma, addr, pmd); | |
1064 | } | |
1065 | ||
1066 | goto out_unlock; | |
1067 | } | |
1068 | ||
f25748e3 DW |
1069 | entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); |
1070 | if (pfn_t_devmap(pfn)) | |
1071 | entry = pmd_mkdevmap(entry); | |
01871e59 | 1072 | if (write) { |
f55e1014 LT |
1073 | entry = pmd_mkyoung(pmd_mkdirty(entry)); |
1074 | entry = maybe_pmd_mkwrite(entry, vma); | |
5cad465d | 1075 | } |
3b6521f5 OH |
1076 | |
1077 | if (pgtable) { | |
1078 | pgtable_trans_huge_deposit(mm, pmd, pgtable); | |
c4812909 | 1079 | mm_inc_nr_ptes(mm); |
c6f3c5ee | 1080 | pgtable = NULL; |
3b6521f5 OH |
1081 | } |
1082 | ||
01871e59 RZ |
1083 | set_pmd_at(mm, addr, pmd, entry); |
1084 | update_mmu_cache_pmd(vma, addr, pmd); | |
c6f3c5ee AK |
1085 | |
1086 | out_unlock: | |
5cad465d | 1087 | spin_unlock(ptl); |
c6f3c5ee AK |
1088 | if (pgtable) |
1089 | pte_free(mm, pgtable); | |
5cad465d MW |
1090 | } |
1091 | ||
9a9731b1 | 1092 | /** |
7b806d22 | 1093 | * vmf_insert_pfn_pmd - insert a pmd size pfn |
9a9731b1 THV |
1094 | * @vmf: Structure describing the fault |
1095 | * @pfn: pfn to insert | |
9a9731b1 THV |
1096 | * @write: whether it's a write fault |
1097 | * | |
7b806d22 | 1098 | * Insert a pmd size pfn. See vmf_insert_pfn() for additional info. |
9a9731b1 THV |
1099 | * |
1100 | * Return: vm_fault_t value. | |
1101 | */ | |
7b806d22 | 1102 | vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write) |
5cad465d | 1103 | { |
fce86ff5 DW |
1104 | unsigned long addr = vmf->address & PMD_MASK; |
1105 | struct vm_area_struct *vma = vmf->vma; | |
7b806d22 | 1106 | pgprot_t pgprot = vma->vm_page_prot; |
3b6521f5 | 1107 | pgtable_t pgtable = NULL; |
fce86ff5 | 1108 | |
5cad465d MW |
1109 | /* |
1110 | * If we had pmd_special, we could avoid all these restrictions, | |
1111 | * but we need to be consistent with PTEs and architectures that | |
1112 | * can't support a 'special' bit. | |
1113 | */ | |
e1fb4a08 DJ |
1114 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
1115 | !pfn_t_devmap(pfn)); | |
5cad465d MW |
1116 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
1117 | (VM_PFNMAP|VM_MIXEDMAP)); | |
1118 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); | |
5cad465d MW |
1119 | |
1120 | if (addr < vma->vm_start || addr >= vma->vm_end) | |
1121 | return VM_FAULT_SIGBUS; | |
308a047c | 1122 | |
3b6521f5 | 1123 | if (arch_needs_pgtable_deposit()) { |
4cf58924 | 1124 | pgtable = pte_alloc_one(vma->vm_mm); |
3b6521f5 OH |
1125 | if (!pgtable) |
1126 | return VM_FAULT_OOM; | |
1127 | } | |
1128 | ||
308a047c BP |
1129 | track_pfn_insert(vma, &pgprot, pfn); |
1130 | ||
fce86ff5 | 1131 | insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable); |
ae18d6dc | 1132 | return VM_FAULT_NOPAGE; |
5cad465d | 1133 | } |
7b806d22 | 1134 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); |
5cad465d | 1135 | |
a00cc7d9 | 1136 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
f55e1014 | 1137 | static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma) |
a00cc7d9 | 1138 | { |
f55e1014 | 1139 | if (likely(vma->vm_flags & VM_WRITE)) |
a00cc7d9 MW |
1140 | pud = pud_mkwrite(pud); |
1141 | return pud; | |
1142 | } | |
1143 | ||
1144 | static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, | |
7b806d22 | 1145 | pud_t *pud, pfn_t pfn, bool write) |
a00cc7d9 MW |
1146 | { |
1147 | struct mm_struct *mm = vma->vm_mm; | |
7b806d22 | 1148 | pgprot_t prot = vma->vm_page_prot; |
a00cc7d9 MW |
1149 | pud_t entry; |
1150 | spinlock_t *ptl; | |
1151 | ||
1152 | ptl = pud_lock(mm, pud); | |
c6f3c5ee AK |
1153 | if (!pud_none(*pud)) { |
1154 | if (write) { | |
1155 | if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { | |
1156 | WARN_ON_ONCE(!is_huge_zero_pud(*pud)); | |
1157 | goto out_unlock; | |
1158 | } | |
1159 | entry = pud_mkyoung(*pud); | |
1160 | entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); | |
1161 | if (pudp_set_access_flags(vma, addr, pud, entry, 1)) | |
1162 | update_mmu_cache_pud(vma, addr, pud); | |
1163 | } | |
1164 | goto out_unlock; | |
1165 | } | |
1166 | ||
a00cc7d9 MW |
1167 | entry = pud_mkhuge(pfn_t_pud(pfn, prot)); |
1168 | if (pfn_t_devmap(pfn)) | |
1169 | entry = pud_mkdevmap(entry); | |
1170 | if (write) { | |
f55e1014 LT |
1171 | entry = pud_mkyoung(pud_mkdirty(entry)); |
1172 | entry = maybe_pud_mkwrite(entry, vma); | |
a00cc7d9 MW |
1173 | } |
1174 | set_pud_at(mm, addr, pud, entry); | |
1175 | update_mmu_cache_pud(vma, addr, pud); | |
c6f3c5ee AK |
1176 | |
1177 | out_unlock: | |
a00cc7d9 MW |
1178 | spin_unlock(ptl); |
1179 | } | |
1180 | ||
9a9731b1 | 1181 | /** |
7b806d22 | 1182 | * vmf_insert_pfn_pud - insert a pud size pfn |
9a9731b1 THV |
1183 | * @vmf: Structure describing the fault |
1184 | * @pfn: pfn to insert | |
9a9731b1 THV |
1185 | * @write: whether it's a write fault |
1186 | * | |
7b806d22 | 1187 | * Insert a pud size pfn. See vmf_insert_pfn() for additional info. |
9a9731b1 THV |
1188 | * |
1189 | * Return: vm_fault_t value. | |
1190 | */ | |
7b806d22 | 1191 | vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write) |
a00cc7d9 | 1192 | { |
fce86ff5 DW |
1193 | unsigned long addr = vmf->address & PUD_MASK; |
1194 | struct vm_area_struct *vma = vmf->vma; | |
7b806d22 | 1195 | pgprot_t pgprot = vma->vm_page_prot; |
fce86ff5 | 1196 | |
a00cc7d9 MW |
1197 | /* |
1198 | * If we had pud_special, we could avoid all these restrictions, | |
1199 | * but we need to be consistent with PTEs and architectures that | |
1200 | * can't support a 'special' bit. | |
1201 | */ | |
62ec0d8c DJ |
1202 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
1203 | !pfn_t_devmap(pfn)); | |
a00cc7d9 MW |
1204 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
1205 | (VM_PFNMAP|VM_MIXEDMAP)); | |
1206 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); | |
a00cc7d9 MW |
1207 | |
1208 | if (addr < vma->vm_start || addr >= vma->vm_end) | |
1209 | return VM_FAULT_SIGBUS; | |
1210 | ||
1211 | track_pfn_insert(vma, &pgprot, pfn); | |
1212 | ||
7b806d22 | 1213 | insert_pfn_pud(vma, addr, vmf->pud, pfn, write); |
a00cc7d9 MW |
1214 | return VM_FAULT_NOPAGE; |
1215 | } | |
7b806d22 | 1216 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); |
a00cc7d9 MW |
1217 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
1218 | ||
3565fce3 | 1219 | static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, |
a69e4717 | 1220 | pmd_t *pmd, bool write) |
3565fce3 DW |
1221 | { |
1222 | pmd_t _pmd; | |
1223 | ||
a8f97366 | 1224 | _pmd = pmd_mkyoung(*pmd); |
a69e4717 | 1225 | if (write) |
a8f97366 | 1226 | _pmd = pmd_mkdirty(_pmd); |
3565fce3 | 1227 | if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK, |
a69e4717 | 1228 | pmd, _pmd, write)) |
3565fce3 DW |
1229 | update_mmu_cache_pmd(vma, addr, pmd); |
1230 | } | |
1231 | ||
1232 | struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, | |
df06b37f | 1233 | pmd_t *pmd, int flags, struct dev_pagemap **pgmap) |
3565fce3 DW |
1234 | { |
1235 | unsigned long pfn = pmd_pfn(*pmd); | |
1236 | struct mm_struct *mm = vma->vm_mm; | |
3565fce3 | 1237 | struct page *page; |
0f089235 | 1238 | int ret; |
3565fce3 DW |
1239 | |
1240 | assert_spin_locked(pmd_lockptr(mm, pmd)); | |
1241 | ||
f6f37321 | 1242 | if (flags & FOLL_WRITE && !pmd_write(*pmd)) |
3565fce3 DW |
1243 | return NULL; |
1244 | ||
1245 | if (pmd_present(*pmd) && pmd_devmap(*pmd)) | |
1246 | /* pass */; | |
1247 | else | |
1248 | return NULL; | |
1249 | ||
1250 | if (flags & FOLL_TOUCH) | |
a69e4717 | 1251 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
3565fce3 DW |
1252 | |
1253 | /* | |
1254 | * device mapped pages can only be returned if the | |
1255 | * caller will manage the page reference count. | |
1256 | */ | |
3faa52c0 | 1257 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
3565fce3 DW |
1258 | return ERR_PTR(-EEXIST); |
1259 | ||
1260 | pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT; | |
df06b37f KB |
1261 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
1262 | if (!*pgmap) | |
3565fce3 DW |
1263 | return ERR_PTR(-EFAULT); |
1264 | page = pfn_to_page(pfn); | |
0f089235 LG |
1265 | ret = try_grab_page(page, flags); |
1266 | if (ret) | |
1267 | page = ERR_PTR(ret); | |
3565fce3 DW |
1268 | |
1269 | return page; | |
1270 | } | |
1271 | ||
71e3aac0 AA |
1272 | int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
1273 | pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, | |
8f34f1ea | 1274 | struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) |
71e3aac0 | 1275 | { |
c4088ebd | 1276 | spinlock_t *dst_ptl, *src_ptl; |
71e3aac0 AA |
1277 | struct page *src_page; |
1278 | pmd_t pmd; | |
12c9d70b | 1279 | pgtable_t pgtable = NULL; |
628d47ce | 1280 | int ret = -ENOMEM; |
71e3aac0 | 1281 | |
628d47ce | 1282 | /* Skip if can be re-fill on fault */ |
8f34f1ea | 1283 | if (!vma_is_anonymous(dst_vma)) |
628d47ce KS |
1284 | return 0; |
1285 | ||
4cf58924 | 1286 | pgtable = pte_alloc_one(dst_mm); |
628d47ce KS |
1287 | if (unlikely(!pgtable)) |
1288 | goto out; | |
71e3aac0 | 1289 | |
c4088ebd KS |
1290 | dst_ptl = pmd_lock(dst_mm, dst_pmd); |
1291 | src_ptl = pmd_lockptr(src_mm, src_pmd); | |
1292 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
71e3aac0 AA |
1293 | |
1294 | ret = -EAGAIN; | |
1295 | pmd = *src_pmd; | |
84c3fc4e ZY |
1296 | |
1297 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
1298 | if (unlikely(is_swap_pmd(pmd))) { | |
1299 | swp_entry_t entry = pmd_to_swp_entry(pmd); | |
1300 | ||
1301 | VM_BUG_ON(!is_pmd_migration_entry(pmd)); | |
6c287605 | 1302 | if (!is_readable_migration_entry(entry)) { |
4dd845b5 AP |
1303 | entry = make_readable_migration_entry( |
1304 | swp_offset(entry)); | |
84c3fc4e | 1305 | pmd = swp_entry_to_pmd(entry); |
ab6e3d09 NH |
1306 | if (pmd_swp_soft_dirty(*src_pmd)) |
1307 | pmd = pmd_swp_mksoft_dirty(pmd); | |
8f34f1ea PX |
1308 | if (pmd_swp_uffd_wp(*src_pmd)) |
1309 | pmd = pmd_swp_mkuffd_wp(pmd); | |
84c3fc4e ZY |
1310 | set_pmd_at(src_mm, addr, src_pmd, pmd); |
1311 | } | |
dd8a67f9 | 1312 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
af5b0f6a | 1313 | mm_inc_nr_ptes(dst_mm); |
dd8a67f9 | 1314 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
8f34f1ea PX |
1315 | if (!userfaultfd_wp(dst_vma)) |
1316 | pmd = pmd_swp_clear_uffd_wp(pmd); | |
84c3fc4e ZY |
1317 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); |
1318 | ret = 0; | |
1319 | goto out_unlock; | |
1320 | } | |
1321 | #endif | |
1322 | ||
628d47ce | 1323 | if (unlikely(!pmd_trans_huge(pmd))) { |
71e3aac0 AA |
1324 | pte_free(dst_mm, pgtable); |
1325 | goto out_unlock; | |
1326 | } | |
fc9fe822 | 1327 | /* |
c4088ebd | 1328 | * When page table lock is held, the huge zero pmd should not be |
fc9fe822 KS |
1329 | * under splitting since we don't split the page itself, only pmd to |
1330 | * a page table. | |
1331 | */ | |
1332 | if (is_huge_zero_pmd(pmd)) { | |
97ae1749 KS |
1333 | /* |
1334 | * get_huge_zero_page() will never allocate a new page here, | |
1335 | * since we already have a zero page to copy. It just takes a | |
1336 | * reference. | |
1337 | */ | |
5fc7a5f6 PX |
1338 | mm_get_huge_zero_page(dst_mm); |
1339 | goto out_zero_page; | |
fc9fe822 | 1340 | } |
de466bd6 | 1341 | |
628d47ce KS |
1342 | src_page = pmd_page(pmd); |
1343 | VM_BUG_ON_PAGE(!PageHead(src_page), src_page); | |
d042035e | 1344 | |
fb3d824d DH |
1345 | get_page(src_page); |
1346 | if (unlikely(page_try_dup_anon_rmap(src_page, true, src_vma))) { | |
1347 | /* Page maybe pinned: split and retry the fault on PTEs. */ | |
1348 | put_page(src_page); | |
d042035e PX |
1349 | pte_free(dst_mm, pgtable); |
1350 | spin_unlock(src_ptl); | |
1351 | spin_unlock(dst_ptl); | |
8f34f1ea | 1352 | __split_huge_pmd(src_vma, src_pmd, addr, false, NULL); |
d042035e PX |
1353 | return -EAGAIN; |
1354 | } | |
628d47ce | 1355 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
5fc7a5f6 | 1356 | out_zero_page: |
c4812909 | 1357 | mm_inc_nr_ptes(dst_mm); |
628d47ce | 1358 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
71e3aac0 | 1359 | pmdp_set_wrprotect(src_mm, addr, src_pmd); |
8f34f1ea PX |
1360 | if (!userfaultfd_wp(dst_vma)) |
1361 | pmd = pmd_clear_uffd_wp(pmd); | |
71e3aac0 AA |
1362 | pmd = pmd_mkold(pmd_wrprotect(pmd)); |
1363 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); | |
71e3aac0 AA |
1364 | |
1365 | ret = 0; | |
1366 | out_unlock: | |
c4088ebd KS |
1367 | spin_unlock(src_ptl); |
1368 | spin_unlock(dst_ptl); | |
71e3aac0 AA |
1369 | out: |
1370 | return ret; | |
1371 | } | |
1372 | ||
a00cc7d9 MW |
1373 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
1374 | static void touch_pud(struct vm_area_struct *vma, unsigned long addr, | |
5fe653e9 | 1375 | pud_t *pud, bool write) |
a00cc7d9 MW |
1376 | { |
1377 | pud_t _pud; | |
1378 | ||
a8f97366 | 1379 | _pud = pud_mkyoung(*pud); |
5fe653e9 | 1380 | if (write) |
a8f97366 | 1381 | _pud = pud_mkdirty(_pud); |
a00cc7d9 | 1382 | if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK, |
5fe653e9 | 1383 | pud, _pud, write)) |
a00cc7d9 MW |
1384 | update_mmu_cache_pud(vma, addr, pud); |
1385 | } | |
1386 | ||
1387 | struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, | |
df06b37f | 1388 | pud_t *pud, int flags, struct dev_pagemap **pgmap) |
a00cc7d9 MW |
1389 | { |
1390 | unsigned long pfn = pud_pfn(*pud); | |
1391 | struct mm_struct *mm = vma->vm_mm; | |
a00cc7d9 | 1392 | struct page *page; |
0f089235 | 1393 | int ret; |
a00cc7d9 MW |
1394 | |
1395 | assert_spin_locked(pud_lockptr(mm, pud)); | |
1396 | ||
f6f37321 | 1397 | if (flags & FOLL_WRITE && !pud_write(*pud)) |
a00cc7d9 MW |
1398 | return NULL; |
1399 | ||
1400 | if (pud_present(*pud) && pud_devmap(*pud)) | |
1401 | /* pass */; | |
1402 | else | |
1403 | return NULL; | |
1404 | ||
1405 | if (flags & FOLL_TOUCH) | |
5fe653e9 | 1406 | touch_pud(vma, addr, pud, flags & FOLL_WRITE); |
a00cc7d9 MW |
1407 | |
1408 | /* | |
1409 | * device mapped pages can only be returned if the | |
1410 | * caller will manage the page reference count. | |
3faa52c0 JH |
1411 | * |
1412 | * At least one of FOLL_GET | FOLL_PIN must be set, so assert that here: | |
a00cc7d9 | 1413 | */ |
3faa52c0 | 1414 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
a00cc7d9 MW |
1415 | return ERR_PTR(-EEXIST); |
1416 | ||
1417 | pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT; | |
df06b37f KB |
1418 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
1419 | if (!*pgmap) | |
a00cc7d9 MW |
1420 | return ERR_PTR(-EFAULT); |
1421 | page = pfn_to_page(pfn); | |
0f089235 LG |
1422 | |
1423 | ret = try_grab_page(page, flags); | |
1424 | if (ret) | |
1425 | page = ERR_PTR(ret); | |
a00cc7d9 MW |
1426 | |
1427 | return page; | |
1428 | } | |
1429 | ||
1430 | int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm, | |
1431 | pud_t *dst_pud, pud_t *src_pud, unsigned long addr, | |
1432 | struct vm_area_struct *vma) | |
1433 | { | |
1434 | spinlock_t *dst_ptl, *src_ptl; | |
1435 | pud_t pud; | |
1436 | int ret; | |
1437 | ||
1438 | dst_ptl = pud_lock(dst_mm, dst_pud); | |
1439 | src_ptl = pud_lockptr(src_mm, src_pud); | |
1440 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
1441 | ||
1442 | ret = -EAGAIN; | |
1443 | pud = *src_pud; | |
1444 | if (unlikely(!pud_trans_huge(pud) && !pud_devmap(pud))) | |
1445 | goto out_unlock; | |
1446 | ||
1447 | /* | |
1448 | * When page table lock is held, the huge zero pud should not be | |
1449 | * under splitting since we don't split the page itself, only pud to | |
1450 | * a page table. | |
1451 | */ | |
1452 | if (is_huge_zero_pud(pud)) { | |
1453 | /* No huge zero pud yet */ | |
1454 | } | |
1455 | ||
fb3d824d DH |
1456 | /* |
1457 | * TODO: once we support anonymous pages, use page_try_dup_anon_rmap() | |
1458 | * and split if duplicating fails. | |
1459 | */ | |
a00cc7d9 MW |
1460 | pudp_set_wrprotect(src_mm, addr, src_pud); |
1461 | pud = pud_mkold(pud_wrprotect(pud)); | |
1462 | set_pud_at(dst_mm, addr, dst_pud, pud); | |
1463 | ||
1464 | ret = 0; | |
1465 | out_unlock: | |
1466 | spin_unlock(src_ptl); | |
1467 | spin_unlock(dst_ptl); | |
1468 | return ret; | |
1469 | } | |
1470 | ||
1471 | void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) | |
1472 | { | |
a00cc7d9 MW |
1473 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
1474 | ||
1475 | vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud); | |
1476 | if (unlikely(!pud_same(*vmf->pud, orig_pud))) | |
1477 | goto unlock; | |
1478 | ||
5fe653e9 | 1479 | touch_pud(vmf->vma, vmf->address, vmf->pud, write); |
a00cc7d9 MW |
1480 | unlock: |
1481 | spin_unlock(vmf->ptl); | |
1482 | } | |
1483 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ | |
1484 | ||
5db4f15c | 1485 | void huge_pmd_set_accessed(struct vm_fault *vmf) |
a1dd450b | 1486 | { |
20f664aa | 1487 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
a1dd450b | 1488 | |
82b0f8c3 | 1489 | vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); |
a69e4717 | 1490 | if (unlikely(!pmd_same(*vmf->pmd, vmf->orig_pmd))) |
a1dd450b WD |
1491 | goto unlock; |
1492 | ||
a69e4717 | 1493 | touch_pmd(vmf->vma, vmf->address, vmf->pmd, write); |
a1dd450b WD |
1494 | |
1495 | unlock: | |
82b0f8c3 | 1496 | spin_unlock(vmf->ptl); |
a1dd450b WD |
1497 | } |
1498 | ||
5db4f15c | 1499 | vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) |
71e3aac0 | 1500 | { |
c89357e2 | 1501 | const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; |
82b0f8c3 | 1502 | struct vm_area_struct *vma = vmf->vma; |
2fad3d14 | 1503 | struct folio *folio; |
3917c802 | 1504 | struct page *page; |
82b0f8c3 | 1505 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
5db4f15c | 1506 | pmd_t orig_pmd = vmf->orig_pmd; |
71e3aac0 | 1507 | |
82b0f8c3 | 1508 | vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd); |
81d1b09c | 1509 | VM_BUG_ON_VMA(!vma->anon_vma, vma); |
3917c802 | 1510 | |
93b4796d | 1511 | if (is_huge_zero_pmd(orig_pmd)) |
3917c802 KS |
1512 | goto fallback; |
1513 | ||
82b0f8c3 | 1514 | spin_lock(vmf->ptl); |
3917c802 KS |
1515 | |
1516 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { | |
1517 | spin_unlock(vmf->ptl); | |
1518 | return 0; | |
1519 | } | |
71e3aac0 AA |
1520 | |
1521 | page = pmd_page(orig_pmd); | |
2fad3d14 | 1522 | folio = page_folio(page); |
f6004e73 | 1523 | VM_BUG_ON_PAGE(!PageHead(page), page); |
3917c802 | 1524 | |
6c287605 DH |
1525 | /* Early check when only holding the PT lock. */ |
1526 | if (PageAnonExclusive(page)) | |
1527 | goto reuse; | |
1528 | ||
2fad3d14 MWO |
1529 | if (!folio_trylock(folio)) { |
1530 | folio_get(folio); | |
ba3c4ce6 | 1531 | spin_unlock(vmf->ptl); |
2fad3d14 | 1532 | folio_lock(folio); |
ba3c4ce6 HY |
1533 | spin_lock(vmf->ptl); |
1534 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { | |
3917c802 | 1535 | spin_unlock(vmf->ptl); |
2fad3d14 MWO |
1536 | folio_unlock(folio); |
1537 | folio_put(folio); | |
3917c802 | 1538 | return 0; |
ba3c4ce6 | 1539 | } |
2fad3d14 | 1540 | folio_put(folio); |
ba3c4ce6 | 1541 | } |
3917c802 | 1542 | |
6c287605 DH |
1543 | /* Recheck after temporarily dropping the PT lock. */ |
1544 | if (PageAnonExclusive(page)) { | |
2fad3d14 | 1545 | folio_unlock(folio); |
6c287605 DH |
1546 | goto reuse; |
1547 | } | |
1548 | ||
3917c802 | 1549 | /* |
2fad3d14 MWO |
1550 | * See do_wp_page(): we can only reuse the folio exclusively if |
1551 | * there are no additional references. Note that we always drain | |
1fec6890 | 1552 | * the LRU cache immediately after adding a THP. |
3917c802 | 1553 | */ |
2fad3d14 MWO |
1554 | if (folio_ref_count(folio) > |
1555 | 1 + folio_test_swapcache(folio) * folio_nr_pages(folio)) | |
3bff7e3f | 1556 | goto unlock_fallback; |
2fad3d14 MWO |
1557 | if (folio_test_swapcache(folio)) |
1558 | folio_free_swap(folio); | |
1559 | if (folio_ref_count(folio) == 1) { | |
71e3aac0 | 1560 | pmd_t entry; |
6c54dc6c | 1561 | |
06968625 | 1562 | folio_move_anon_rmap(folio, vma); |
5ca43289 | 1563 | SetPageAnonExclusive(page); |
2fad3d14 | 1564 | folio_unlock(folio); |
6c287605 | 1565 | reuse: |
c89357e2 DH |
1566 | if (unlikely(unshare)) { |
1567 | spin_unlock(vmf->ptl); | |
1568 | return 0; | |
1569 | } | |
71e3aac0 | 1570 | entry = pmd_mkyoung(orig_pmd); |
f55e1014 | 1571 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
3917c802 | 1572 | if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1)) |
82b0f8c3 | 1573 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
82b0f8c3 | 1574 | spin_unlock(vmf->ptl); |
cb8d8633 | 1575 | return 0; |
71e3aac0 | 1576 | } |
3917c802 | 1577 | |
3bff7e3f | 1578 | unlock_fallback: |
2fad3d14 | 1579 | folio_unlock(folio); |
82b0f8c3 | 1580 | spin_unlock(vmf->ptl); |
3917c802 KS |
1581 | fallback: |
1582 | __split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL); | |
1583 | return VM_FAULT_FALLBACK; | |
71e3aac0 AA |
1584 | } |
1585 | ||
c27f479e DH |
1586 | static inline bool can_change_pmd_writable(struct vm_area_struct *vma, |
1587 | unsigned long addr, pmd_t pmd) | |
1588 | { | |
1589 | struct page *page; | |
1590 | ||
1591 | if (WARN_ON_ONCE(!(vma->vm_flags & VM_WRITE))) | |
1592 | return false; | |
1593 | ||
1594 | /* Don't touch entries that are not even readable (NUMA hinting). */ | |
1595 | if (pmd_protnone(pmd)) | |
1596 | return false; | |
1597 | ||
1598 | /* Do we need write faults for softdirty tracking? */ | |
1599 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) | |
1600 | return false; | |
1601 | ||
1602 | /* Do we need write faults for uffd-wp tracking? */ | |
1603 | if (userfaultfd_huge_pmd_wp(vma, pmd)) | |
1604 | return false; | |
1605 | ||
1606 | if (!(vma->vm_flags & VM_SHARED)) { | |
1607 | /* See can_change_pte_writable(). */ | |
1608 | page = vm_normal_page_pmd(vma, addr, pmd); | |
1609 | return page && PageAnon(page) && PageAnonExclusive(page); | |
1610 | } | |
1611 | ||
1612 | /* See can_change_pte_writable(). */ | |
1613 | return pmd_dirty(pmd); | |
1614 | } | |
1615 | ||
5535be30 DH |
1616 | /* FOLL_FORCE can write to even unwritable PMDs in COW mappings. */ |
1617 | static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, | |
1618 | struct vm_area_struct *vma, | |
1619 | unsigned int flags) | |
8310d48b | 1620 | { |
5535be30 DH |
1621 | /* If the pmd is writable, we can write to the page. */ |
1622 | if (pmd_write(pmd)) | |
1623 | return true; | |
1624 | ||
1625 | /* Maybe FOLL_FORCE is set to override it? */ | |
1626 | if (!(flags & FOLL_FORCE)) | |
1627 | return false; | |
1628 | ||
1629 | /* But FOLL_FORCE has no effect on shared mappings */ | |
1630 | if (vma->vm_flags & (VM_MAYSHARE | VM_SHARED)) | |
1631 | return false; | |
1632 | ||
1633 | /* ... or read-only private ones */ | |
1634 | if (!(vma->vm_flags & VM_MAYWRITE)) | |
1635 | return false; | |
1636 | ||
1637 | /* ... or already writable ones that just need to take a write fault */ | |
1638 | if (vma->vm_flags & VM_WRITE) | |
1639 | return false; | |
1640 | ||
1641 | /* | |
1642 | * See can_change_pte_writable(): we broke COW and could map the page | |
1643 | * writable if we have an exclusive anonymous page ... | |
1644 | */ | |
1645 | if (!page || !PageAnon(page) || !PageAnonExclusive(page)) | |
1646 | return false; | |
1647 | ||
1648 | /* ... and a write-fault isn't required for other reasons. */ | |
1649 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) | |
1650 | return false; | |
1651 | return !userfaultfd_huge_pmd_wp(vma, pmd); | |
8310d48b KF |
1652 | } |
1653 | ||
b676b293 | 1654 | struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, |
71e3aac0 AA |
1655 | unsigned long addr, |
1656 | pmd_t *pmd, | |
1657 | unsigned int flags) | |
1658 | { | |
b676b293 | 1659 | struct mm_struct *mm = vma->vm_mm; |
5535be30 | 1660 | struct page *page; |
0f089235 | 1661 | int ret; |
71e3aac0 | 1662 | |
c4088ebd | 1663 | assert_spin_locked(pmd_lockptr(mm, pmd)); |
71e3aac0 | 1664 | |
5535be30 DH |
1665 | page = pmd_page(*pmd); |
1666 | VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); | |
1667 | ||
1668 | if ((flags & FOLL_WRITE) && | |
1669 | !can_follow_write_pmd(*pmd, page, vma, flags)) | |
1670 | return NULL; | |
71e3aac0 | 1671 | |
85facf25 KS |
1672 | /* Avoid dumping huge zero page */ |
1673 | if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd)) | |
1674 | return ERR_PTR(-EFAULT); | |
1675 | ||
d74943a2 | 1676 | if (pmd_protnone(*pmd) && !gup_can_follow_protnone(vma, flags)) |
5535be30 | 1677 | return NULL; |
3faa52c0 | 1678 | |
84209e87 | 1679 | if (!pmd_write(*pmd) && gup_must_unshare(vma, flags, page)) |
a7f22660 DH |
1680 | return ERR_PTR(-EMLINK); |
1681 | ||
b6a2619c DH |
1682 | VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && |
1683 | !PageAnonExclusive(page), page); | |
1684 | ||
0f089235 LG |
1685 | ret = try_grab_page(page, flags); |
1686 | if (ret) | |
1687 | return ERR_PTR(ret); | |
3faa52c0 | 1688 | |
3565fce3 | 1689 | if (flags & FOLL_TOUCH) |
a69e4717 | 1690 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
3faa52c0 | 1691 | |
71e3aac0 | 1692 | page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; |
ca120cf6 | 1693 | VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); |
71e3aac0 | 1694 | |
71e3aac0 AA |
1695 | return page; |
1696 | } | |
1697 | ||
d10e63f2 | 1698 | /* NUMA hinting page fault entry point for trans huge pmds */ |
5db4f15c | 1699 | vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) |
d10e63f2 | 1700 | { |
82b0f8c3 | 1701 | struct vm_area_struct *vma = vmf->vma; |
c5b5a3dd YS |
1702 | pmd_t oldpmd = vmf->orig_pmd; |
1703 | pmd_t pmd; | |
667ffc31 | 1704 | struct folio *folio; |
82b0f8c3 | 1705 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
667ffc31 | 1706 | int nid = NUMA_NO_NODE; |
33024536 | 1707 | int target_nid, last_cpupid = (-1 & LAST_CPUPID_MASK); |
6a56ccbc | 1708 | bool migrated = false, writable = false; |
6688cc05 | 1709 | int flags = 0; |
d10e63f2 | 1710 | |
82b0f8c3 | 1711 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
c5b5a3dd | 1712 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { |
82b0f8c3 | 1713 | spin_unlock(vmf->ptl); |
de466bd6 MG |
1714 | goto out; |
1715 | } | |
1716 | ||
c5b5a3dd | 1717 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); |
6a56ccbc DH |
1718 | |
1719 | /* | |
1720 | * Detect now whether the PMD could be writable; this information | |
1721 | * is only valid while holding the PT lock. | |
1722 | */ | |
1723 | writable = pmd_write(pmd); | |
1724 | if (!writable && vma_wants_manual_pte_write_upgrade(vma) && | |
1725 | can_change_pmd_writable(vma, vmf->address, pmd)) | |
1726 | writable = true; | |
1727 | ||
667ffc31 KW |
1728 | folio = vm_normal_folio_pmd(vma, haddr, pmd); |
1729 | if (!folio) | |
c5b5a3dd YS |
1730 | goto out_map; |
1731 | ||
1732 | /* See similar comment in do_numa_page for explanation */ | |
6a56ccbc | 1733 | if (!writable) |
c5b5a3dd YS |
1734 | flags |= TNF_NO_GROUP; |
1735 | ||
667ffc31 | 1736 | nid = folio_nid(folio); |
33024536 HY |
1737 | /* |
1738 | * For memory tiering mode, cpupid of slow memory page is used | |
1739 | * to record page access time. So use default value. | |
1740 | */ | |
667ffc31 | 1741 | if (node_is_toptier(nid)) |
c4a8d2fa | 1742 | last_cpupid = folio_last_cpupid(folio); |
cda6d936 | 1743 | target_nid = numa_migrate_prep(folio, vma, haddr, nid, &flags); |
c5b5a3dd | 1744 | if (target_nid == NUMA_NO_NODE) { |
667ffc31 | 1745 | folio_put(folio); |
c5b5a3dd YS |
1746 | goto out_map; |
1747 | } | |
1748 | ||
82b0f8c3 | 1749 | spin_unlock(vmf->ptl); |
6a56ccbc | 1750 | writable = false; |
8b1b436d | 1751 | |
667ffc31 | 1752 | migrated = migrate_misplaced_folio(folio, vma, target_nid); |
6688cc05 PZ |
1753 | if (migrated) { |
1754 | flags |= TNF_MIGRATED; | |
667ffc31 | 1755 | nid = target_nid; |
c5b5a3dd | 1756 | } else { |
074c2381 | 1757 | flags |= TNF_MIGRATE_FAIL; |
c5b5a3dd YS |
1758 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
1759 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { | |
1760 | spin_unlock(vmf->ptl); | |
1761 | goto out; | |
1762 | } | |
1763 | goto out_map; | |
1764 | } | |
b8916634 MG |
1765 | |
1766 | out: | |
667ffc31 KW |
1767 | if (nid != NUMA_NO_NODE) |
1768 | task_numa_fault(last_cpupid, nid, HPAGE_PMD_NR, flags); | |
8191acbd | 1769 | |
d10e63f2 | 1770 | return 0; |
c5b5a3dd YS |
1771 | |
1772 | out_map: | |
1773 | /* Restore the PMD */ | |
1774 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); | |
1775 | pmd = pmd_mkyoung(pmd); | |
6a56ccbc | 1776 | if (writable) |
161e393c | 1777 | pmd = pmd_mkwrite(pmd, vma); |
c5b5a3dd YS |
1778 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd); |
1779 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); | |
1780 | spin_unlock(vmf->ptl); | |
1781 | goto out; | |
d10e63f2 MG |
1782 | } |
1783 | ||
319904ad HY |
1784 | /* |
1785 | * Return true if we do MADV_FREE successfully on entire pmd page. | |
1786 | * Otherwise, return false. | |
1787 | */ | |
1788 | bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
b8d3c4c3 | 1789 | pmd_t *pmd, unsigned long addr, unsigned long next) |
b8d3c4c3 MK |
1790 | { |
1791 | spinlock_t *ptl; | |
1792 | pmd_t orig_pmd; | |
fc986a38 | 1793 | struct folio *folio; |
b8d3c4c3 | 1794 | struct mm_struct *mm = tlb->mm; |
319904ad | 1795 | bool ret = false; |
b8d3c4c3 | 1796 | |
ed6a7935 | 1797 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
07e32661 | 1798 | |
b6ec57f4 KS |
1799 | ptl = pmd_trans_huge_lock(pmd, vma); |
1800 | if (!ptl) | |
25eedabe | 1801 | goto out_unlocked; |
b8d3c4c3 MK |
1802 | |
1803 | orig_pmd = *pmd; | |
319904ad | 1804 | if (is_huge_zero_pmd(orig_pmd)) |
b8d3c4c3 | 1805 | goto out; |
b8d3c4c3 | 1806 | |
84c3fc4e ZY |
1807 | if (unlikely(!pmd_present(orig_pmd))) { |
1808 | VM_BUG_ON(thp_migration_supported() && | |
1809 | !is_pmd_migration_entry(orig_pmd)); | |
1810 | goto out; | |
1811 | } | |
1812 | ||
fc986a38 | 1813 | folio = pfn_folio(pmd_pfn(orig_pmd)); |
b8d3c4c3 | 1814 | /* |
fc986a38 KW |
1815 | * If other processes are mapping this folio, we couldn't discard |
1816 | * the folio unless they all do MADV_FREE so let's skip the folio. | |
b8d3c4c3 | 1817 | */ |
20b18aad | 1818 | if (folio_estimated_sharers(folio) != 1) |
b8d3c4c3 MK |
1819 | goto out; |
1820 | ||
fc986a38 | 1821 | if (!folio_trylock(folio)) |
b8d3c4c3 MK |
1822 | goto out; |
1823 | ||
1824 | /* | |
1825 | * If user want to discard part-pages of THP, split it so MADV_FREE | |
1826 | * will deactivate only them. | |
1827 | */ | |
1828 | if (next - addr != HPAGE_PMD_SIZE) { | |
fc986a38 | 1829 | folio_get(folio); |
b8d3c4c3 | 1830 | spin_unlock(ptl); |
fc986a38 KW |
1831 | split_folio(folio); |
1832 | folio_unlock(folio); | |
1833 | folio_put(folio); | |
b8d3c4c3 MK |
1834 | goto out_unlocked; |
1835 | } | |
1836 | ||
fc986a38 KW |
1837 | if (folio_test_dirty(folio)) |
1838 | folio_clear_dirty(folio); | |
1839 | folio_unlock(folio); | |
b8d3c4c3 | 1840 | |
b8d3c4c3 | 1841 | if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) { |
58ceeb6b | 1842 | pmdp_invalidate(vma, addr, pmd); |
b8d3c4c3 MK |
1843 | orig_pmd = pmd_mkold(orig_pmd); |
1844 | orig_pmd = pmd_mkclean(orig_pmd); | |
1845 | ||
1846 | set_pmd_at(mm, addr, pmd, orig_pmd); | |
1847 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); | |
1848 | } | |
802a3a92 | 1849 | |
6a6fe9eb | 1850 | folio_mark_lazyfree(folio); |
319904ad | 1851 | ret = true; |
b8d3c4c3 MK |
1852 | out: |
1853 | spin_unlock(ptl); | |
1854 | out_unlocked: | |
1855 | return ret; | |
1856 | } | |
1857 | ||
953c66c2 AK |
1858 | static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) |
1859 | { | |
1860 | pgtable_t pgtable; | |
1861 | ||
1862 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); | |
1863 | pte_free(mm, pgtable); | |
c4812909 | 1864 | mm_dec_nr_ptes(mm); |
953c66c2 AK |
1865 | } |
1866 | ||
71e3aac0 | 1867 | int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
f21760b1 | 1868 | pmd_t *pmd, unsigned long addr) |
71e3aac0 | 1869 | { |
da146769 | 1870 | pmd_t orig_pmd; |
bf929152 | 1871 | spinlock_t *ptl; |
71e3aac0 | 1872 | |
ed6a7935 | 1873 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
07e32661 | 1874 | |
b6ec57f4 KS |
1875 | ptl = __pmd_trans_huge_lock(pmd, vma); |
1876 | if (!ptl) | |
da146769 KS |
1877 | return 0; |
1878 | /* | |
1879 | * For architectures like ppc64 we look at deposited pgtable | |
1880 | * when calling pmdp_huge_get_and_clear. So do the | |
1881 | * pgtable_trans_huge_withdraw after finishing pmdp related | |
1882 | * operations. | |
1883 | */ | |
93a98695 AK |
1884 | orig_pmd = pmdp_huge_get_and_clear_full(vma, addr, pmd, |
1885 | tlb->fullmm); | |
e5136e87 | 1886 | arch_check_zapped_pmd(vma, orig_pmd); |
da146769 | 1887 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); |
2484ca9b | 1888 | if (vma_is_special_huge(vma)) { |
3b6521f5 OH |
1889 | if (arch_needs_pgtable_deposit()) |
1890 | zap_deposited_table(tlb->mm, pmd); | |
da146769 | 1891 | spin_unlock(ptl); |
da146769 | 1892 | } else if (is_huge_zero_pmd(orig_pmd)) { |
c14a6eb4 | 1893 | zap_deposited_table(tlb->mm, pmd); |
da146769 | 1894 | spin_unlock(ptl); |
da146769 | 1895 | } else { |
616b8371 ZY |
1896 | struct page *page = NULL; |
1897 | int flush_needed = 1; | |
1898 | ||
1899 | if (pmd_present(orig_pmd)) { | |
1900 | page = pmd_page(orig_pmd); | |
cea86fe2 | 1901 | page_remove_rmap(page, vma, true); |
616b8371 ZY |
1902 | VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); |
1903 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
1904 | } else if (thp_migration_supported()) { | |
1905 | swp_entry_t entry; | |
1906 | ||
1907 | VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); | |
1908 | entry = pmd_to_swp_entry(orig_pmd); | |
af5cdaf8 | 1909 | page = pfn_swap_entry_to_page(entry); |
616b8371 ZY |
1910 | flush_needed = 0; |
1911 | } else | |
1912 | WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!"); | |
1913 | ||
b5072380 | 1914 | if (PageAnon(page)) { |
c14a6eb4 | 1915 | zap_deposited_table(tlb->mm, pmd); |
b5072380 KS |
1916 | add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); |
1917 | } else { | |
953c66c2 AK |
1918 | if (arch_needs_pgtable_deposit()) |
1919 | zap_deposited_table(tlb->mm, pmd); | |
fadae295 | 1920 | add_mm_counter(tlb->mm, mm_counter_file(page), -HPAGE_PMD_NR); |
b5072380 | 1921 | } |
616b8371 | 1922 | |
da146769 | 1923 | spin_unlock(ptl); |
616b8371 ZY |
1924 | if (flush_needed) |
1925 | tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE); | |
025c5b24 | 1926 | } |
da146769 | 1927 | return 1; |
71e3aac0 AA |
1928 | } |
1929 | ||
1dd38b6c AK |
1930 | #ifndef pmd_move_must_withdraw |
1931 | static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl, | |
1932 | spinlock_t *old_pmd_ptl, | |
1933 | struct vm_area_struct *vma) | |
1934 | { | |
1935 | /* | |
1936 | * With split pmd lock we also need to move preallocated | |
1937 | * PTE page table if new_pmd is on different PMD page table. | |
1938 | * | |
1939 | * We also don't deposit and withdraw tables for file pages. | |
1940 | */ | |
1941 | return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma); | |
1942 | } | |
1943 | #endif | |
1944 | ||
ab6e3d09 NH |
1945 | static pmd_t move_soft_dirty_pmd(pmd_t pmd) |
1946 | { | |
1947 | #ifdef CONFIG_MEM_SOFT_DIRTY | |
1948 | if (unlikely(is_pmd_migration_entry(pmd))) | |
1949 | pmd = pmd_swp_mksoft_dirty(pmd); | |
1950 | else if (pmd_present(pmd)) | |
1951 | pmd = pmd_mksoft_dirty(pmd); | |
1952 | #endif | |
1953 | return pmd; | |
1954 | } | |
1955 | ||
bf8616d5 | 1956 | bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, |
b8aa9d9d | 1957 | unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) |
37a1c49a | 1958 | { |
bf929152 | 1959 | spinlock_t *old_ptl, *new_ptl; |
37a1c49a | 1960 | pmd_t pmd; |
37a1c49a | 1961 | struct mm_struct *mm = vma->vm_mm; |
5d190420 | 1962 | bool force_flush = false; |
37a1c49a | 1963 | |
37a1c49a AA |
1964 | /* |
1965 | * The destination pmd shouldn't be established, free_pgtables() | |
a5be621e HD |
1966 | * should have released it; but move_page_tables() might have already |
1967 | * inserted a page table, if racing against shmem/file collapse. | |
37a1c49a | 1968 | */ |
a5be621e | 1969 | if (!pmd_none(*new_pmd)) { |
37a1c49a | 1970 | VM_BUG_ON(pmd_trans_huge(*new_pmd)); |
4b471e88 | 1971 | return false; |
37a1c49a AA |
1972 | } |
1973 | ||
bf929152 KS |
1974 | /* |
1975 | * We don't have to worry about the ordering of src and dst | |
c1e8d7c6 | 1976 | * ptlocks because exclusive mmap_lock prevents deadlock. |
bf929152 | 1977 | */ |
b6ec57f4 KS |
1978 | old_ptl = __pmd_trans_huge_lock(old_pmd, vma); |
1979 | if (old_ptl) { | |
bf929152 KS |
1980 | new_ptl = pmd_lockptr(mm, new_pmd); |
1981 | if (new_ptl != old_ptl) | |
1982 | spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); | |
8809aa2d | 1983 | pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); |
eb66ae03 | 1984 | if (pmd_present(pmd)) |
a2ce2666 | 1985 | force_flush = true; |
025c5b24 | 1986 | VM_BUG_ON(!pmd_none(*new_pmd)); |
3592806c | 1987 | |
1dd38b6c | 1988 | if (pmd_move_must_withdraw(new_ptl, old_ptl, vma)) { |
b3084f4d | 1989 | pgtable_t pgtable; |
3592806c KS |
1990 | pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); |
1991 | pgtable_trans_huge_deposit(mm, new_pmd, pgtable); | |
3592806c | 1992 | } |
ab6e3d09 NH |
1993 | pmd = move_soft_dirty_pmd(pmd); |
1994 | set_pmd_at(mm, new_addr, new_pmd, pmd); | |
5d190420 | 1995 | if (force_flush) |
7c38f181 | 1996 | flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); |
eb66ae03 LT |
1997 | if (new_ptl != old_ptl) |
1998 | spin_unlock(new_ptl); | |
bf929152 | 1999 | spin_unlock(old_ptl); |
4b471e88 | 2000 | return true; |
37a1c49a | 2001 | } |
4b471e88 | 2002 | return false; |
37a1c49a AA |
2003 | } |
2004 | ||
f123d74a MG |
2005 | /* |
2006 | * Returns | |
2007 | * - 0 if PMD could not be locked | |
f0953a1b | 2008 | * - 1 if PMD was locked but protections unchanged and TLB flush unnecessary |
e346e668 | 2009 | * or if prot_numa but THP migration is not supported |
f0953a1b | 2010 | * - HPAGE_PMD_NR if protections changed and TLB flush necessary |
f123d74a | 2011 | */ |
4a18419f NA |
2012 | int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
2013 | pmd_t *pmd, unsigned long addr, pgprot_t newprot, | |
2014 | unsigned long cp_flags) | |
cd7548ab JW |
2015 | { |
2016 | struct mm_struct *mm = vma->vm_mm; | |
bf929152 | 2017 | spinlock_t *ptl; |
c9fe6656 | 2018 | pmd_t oldpmd, entry; |
58705444 | 2019 | bool prot_numa = cp_flags & MM_CP_PROT_NUMA; |
292924b2 PX |
2020 | bool uffd_wp = cp_flags & MM_CP_UFFD_WP; |
2021 | bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; | |
6a56ccbc | 2022 | int ret = 1; |
cd7548ab | 2023 | |
4a18419f NA |
2024 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
2025 | ||
e346e668 YS |
2026 | if (prot_numa && !thp_migration_supported()) |
2027 | return 1; | |
2028 | ||
b6ec57f4 | 2029 | ptl = __pmd_trans_huge_lock(pmd, vma); |
0a85e51d KS |
2030 | if (!ptl) |
2031 | return 0; | |
e944fd67 | 2032 | |
84c3fc4e ZY |
2033 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION |
2034 | if (is_swap_pmd(*pmd)) { | |
2035 | swp_entry_t entry = pmd_to_swp_entry(*pmd); | |
d986ba2b | 2036 | struct folio *folio = page_folio(pfn_swap_entry_to_page(entry)); |
24bf08c4 | 2037 | pmd_t newpmd; |
84c3fc4e ZY |
2038 | |
2039 | VM_BUG_ON(!is_pmd_migration_entry(*pmd)); | |
4dd845b5 | 2040 | if (is_writable_migration_entry(entry)) { |
84c3fc4e ZY |
2041 | /* |
2042 | * A protection check is difficult so | |
2043 | * just be safe and disable write | |
2044 | */ | |
d986ba2b | 2045 | if (folio_test_anon(folio)) |
6c287605 DH |
2046 | entry = make_readable_exclusive_migration_entry(swp_offset(entry)); |
2047 | else | |
2048 | entry = make_readable_migration_entry(swp_offset(entry)); | |
84c3fc4e | 2049 | newpmd = swp_entry_to_pmd(entry); |
ab6e3d09 NH |
2050 | if (pmd_swp_soft_dirty(*pmd)) |
2051 | newpmd = pmd_swp_mksoft_dirty(newpmd); | |
24bf08c4 DH |
2052 | } else { |
2053 | newpmd = *pmd; | |
84c3fc4e | 2054 | } |
24bf08c4 DH |
2055 | |
2056 | if (uffd_wp) | |
2057 | newpmd = pmd_swp_mkuffd_wp(newpmd); | |
2058 | else if (uffd_wp_resolve) | |
2059 | newpmd = pmd_swp_clear_uffd_wp(newpmd); | |
2060 | if (!pmd_same(*pmd, newpmd)) | |
2061 | set_pmd_at(mm, addr, pmd, newpmd); | |
84c3fc4e ZY |
2062 | goto unlock; |
2063 | } | |
2064 | #endif | |
2065 | ||
a1a3a2fc | 2066 | if (prot_numa) { |
d986ba2b | 2067 | struct folio *folio; |
33024536 | 2068 | bool toptier; |
a1a3a2fc HY |
2069 | /* |
2070 | * Avoid trapping faults against the zero page. The read-only | |
2071 | * data is likely to be read-cached on the local CPU and | |
2072 | * local/remote hits to the zero page are not interesting. | |
2073 | */ | |
2074 | if (is_huge_zero_pmd(*pmd)) | |
2075 | goto unlock; | |
025c5b24 | 2076 | |
a1a3a2fc HY |
2077 | if (pmd_protnone(*pmd)) |
2078 | goto unlock; | |
0a85e51d | 2079 | |
d986ba2b KW |
2080 | folio = page_folio(pmd_page(*pmd)); |
2081 | toptier = node_is_toptier(folio_nid(folio)); | |
a1a3a2fc HY |
2082 | /* |
2083 | * Skip scanning top tier node if normal numa | |
2084 | * balancing is disabled | |
2085 | */ | |
2086 | if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && | |
33024536 | 2087 | toptier) |
a1a3a2fc | 2088 | goto unlock; |
33024536 HY |
2089 | |
2090 | if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING && | |
2091 | !toptier) | |
d986ba2b KW |
2092 | folio_xchg_access_time(folio, |
2093 | jiffies_to_msecs(jiffies)); | |
a1a3a2fc | 2094 | } |
ced10803 | 2095 | /* |
3e4e28c5 | 2096 | * In case prot_numa, we are under mmap_read_lock(mm). It's critical |
ced10803 | 2097 | * to not clear pmd intermittently to avoid race with MADV_DONTNEED |
3e4e28c5 | 2098 | * which is also under mmap_read_lock(mm): |
ced10803 KS |
2099 | * |
2100 | * CPU0: CPU1: | |
2101 | * change_huge_pmd(prot_numa=1) | |
2102 | * pmdp_huge_get_and_clear_notify() | |
2103 | * madvise_dontneed() | |
2104 | * zap_pmd_range() | |
2105 | * pmd_trans_huge(*pmd) == 0 (without ptl) | |
2106 | * // skip the pmd | |
2107 | * set_pmd_at(); | |
2108 | * // pmd is re-established | |
2109 | * | |
2110 | * The race makes MADV_DONTNEED miss the huge pmd and don't clear it | |
2111 | * which may break userspace. | |
2112 | * | |
4f831457 | 2113 | * pmdp_invalidate_ad() is required to make sure we don't miss |
ced10803 KS |
2114 | * dirty/young flags set by hardware. |
2115 | */ | |
4f831457 | 2116 | oldpmd = pmdp_invalidate_ad(vma, addr, pmd); |
ced10803 | 2117 | |
c9fe6656 | 2118 | entry = pmd_modify(oldpmd, newprot); |
f1eb1bac | 2119 | if (uffd_wp) |
292924b2 | 2120 | entry = pmd_mkuffd_wp(entry); |
f1eb1bac | 2121 | else if (uffd_wp_resolve) |
292924b2 PX |
2122 | /* |
2123 | * Leave the write bit to be handled by PF interrupt | |
2124 | * handler, then things like COW could be properly | |
2125 | * handled. | |
2126 | */ | |
2127 | entry = pmd_clear_uffd_wp(entry); | |
c27f479e DH |
2128 | |
2129 | /* See change_pte_range(). */ | |
2130 | if ((cp_flags & MM_CP_TRY_CHANGE_WRITABLE) && !pmd_write(entry) && | |
2131 | can_change_pmd_writable(vma, addr, entry)) | |
161e393c | 2132 | entry = pmd_mkwrite(entry, vma); |
c27f479e | 2133 | |
0a85e51d KS |
2134 | ret = HPAGE_PMD_NR; |
2135 | set_pmd_at(mm, addr, pmd, entry); | |
4a18419f | 2136 | |
c9fe6656 NA |
2137 | if (huge_pmd_needs_flush(oldpmd, entry)) |
2138 | tlb_flush_pmd_range(tlb, addr, HPAGE_PMD_SIZE); | |
0a85e51d KS |
2139 | unlock: |
2140 | spin_unlock(ptl); | |
025c5b24 NH |
2141 | return ret; |
2142 | } | |
2143 | ||
adef4406 AA |
2144 | #ifdef CONFIG_USERFAULTFD |
2145 | /* | |
2146 | * The PT lock for src_pmd and the mmap_lock for reading are held by | |
2147 | * the caller, but it must return after releasing the page_table_lock. | |
2148 | * Just move the page from src_pmd to dst_pmd if possible. | |
2149 | * Return zero if succeeded in moving the page, -EAGAIN if it needs to be | |
2150 | * repeated by the caller, or other errors in case of failure. | |
2151 | */ | |
2152 | int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pmd_t dst_pmdval, | |
2153 | struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, | |
2154 | unsigned long dst_addr, unsigned long src_addr) | |
2155 | { | |
2156 | pmd_t _dst_pmd, src_pmdval; | |
2157 | struct page *src_page; | |
2158 | struct folio *src_folio; | |
2159 | struct anon_vma *src_anon_vma; | |
2160 | spinlock_t *src_ptl, *dst_ptl; | |
2161 | pgtable_t src_pgtable; | |
2162 | struct mmu_notifier_range range; | |
2163 | int err = 0; | |
2164 | ||
2165 | src_pmdval = *src_pmd; | |
2166 | src_ptl = pmd_lockptr(mm, src_pmd); | |
2167 | ||
2168 | lockdep_assert_held(src_ptl); | |
2169 | mmap_assert_locked(mm); | |
2170 | ||
2171 | /* Sanity checks before the operation */ | |
2172 | if (WARN_ON_ONCE(!pmd_none(dst_pmdval)) || WARN_ON_ONCE(src_addr & ~HPAGE_PMD_MASK) || | |
2173 | WARN_ON_ONCE(dst_addr & ~HPAGE_PMD_MASK)) { | |
2174 | spin_unlock(src_ptl); | |
2175 | return -EINVAL; | |
2176 | } | |
2177 | ||
2178 | if (!pmd_trans_huge(src_pmdval)) { | |
2179 | spin_unlock(src_ptl); | |
2180 | if (is_pmd_migration_entry(src_pmdval)) { | |
2181 | pmd_migration_entry_wait(mm, &src_pmdval); | |
2182 | return -EAGAIN; | |
2183 | } | |
2184 | return -ENOENT; | |
2185 | } | |
2186 | ||
2187 | src_page = pmd_page(src_pmdval); | |
2188 | if (unlikely(!PageAnonExclusive(src_page))) { | |
2189 | spin_unlock(src_ptl); | |
2190 | return -EBUSY; | |
2191 | } | |
2192 | ||
2193 | src_folio = page_folio(src_page); | |
2194 | folio_get(src_folio); | |
2195 | spin_unlock(src_ptl); | |
2196 | ||
2197 | flush_cache_range(src_vma, src_addr, src_addr + HPAGE_PMD_SIZE); | |
2198 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, src_addr, | |
2199 | src_addr + HPAGE_PMD_SIZE); | |
2200 | mmu_notifier_invalidate_range_start(&range); | |
2201 | ||
2202 | folio_lock(src_folio); | |
2203 | ||
2204 | /* | |
2205 | * split_huge_page walks the anon_vma chain without the page | |
2206 | * lock. Serialize against it with the anon_vma lock, the page | |
2207 | * lock is not enough. | |
2208 | */ | |
2209 | src_anon_vma = folio_get_anon_vma(src_folio); | |
2210 | if (!src_anon_vma) { | |
2211 | err = -EAGAIN; | |
2212 | goto unlock_folio; | |
2213 | } | |
2214 | anon_vma_lock_write(src_anon_vma); | |
2215 | ||
2216 | dst_ptl = pmd_lockptr(mm, dst_pmd); | |
2217 | double_pt_lock(src_ptl, dst_ptl); | |
2218 | if (unlikely(!pmd_same(*src_pmd, src_pmdval) || | |
2219 | !pmd_same(*dst_pmd, dst_pmdval))) { | |
2220 | err = -EAGAIN; | |
2221 | goto unlock_ptls; | |
2222 | } | |
2223 | if (folio_maybe_dma_pinned(src_folio) || | |
2224 | !PageAnonExclusive(&src_folio->page)) { | |
2225 | err = -EBUSY; | |
2226 | goto unlock_ptls; | |
2227 | } | |
2228 | ||
2229 | if (WARN_ON_ONCE(!folio_test_head(src_folio)) || | |
2230 | WARN_ON_ONCE(!folio_test_anon(src_folio))) { | |
2231 | err = -EBUSY; | |
2232 | goto unlock_ptls; | |
2233 | } | |
2234 | ||
2235 | folio_move_anon_rmap(src_folio, dst_vma); | |
2236 | WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); | |
2237 | ||
2238 | src_pmdval = pmdp_huge_clear_flush(src_vma, src_addr, src_pmd); | |
2239 | /* Folio got pinned from under us. Put it back and fail the move. */ | |
2240 | if (folio_maybe_dma_pinned(src_folio)) { | |
2241 | set_pmd_at(mm, src_addr, src_pmd, src_pmdval); | |
2242 | err = -EBUSY; | |
2243 | goto unlock_ptls; | |
2244 | } | |
2245 | ||
2246 | _dst_pmd = mk_huge_pmd(&src_folio->page, dst_vma->vm_page_prot); | |
2247 | /* Follow mremap() behavior and treat the entry dirty after the move */ | |
2248 | _dst_pmd = pmd_mkwrite(pmd_mkdirty(_dst_pmd), dst_vma); | |
2249 | set_pmd_at(mm, dst_addr, dst_pmd, _dst_pmd); | |
2250 | ||
2251 | src_pgtable = pgtable_trans_huge_withdraw(mm, src_pmd); | |
2252 | pgtable_trans_huge_deposit(mm, dst_pmd, src_pgtable); | |
2253 | unlock_ptls: | |
2254 | double_pt_unlock(src_ptl, dst_ptl); | |
2255 | anon_vma_unlock_write(src_anon_vma); | |
2256 | put_anon_vma(src_anon_vma); | |
2257 | unlock_folio: | |
2258 | /* unblock rmap walks */ | |
2259 | folio_unlock(src_folio); | |
2260 | mmu_notifier_invalidate_range_end(&range); | |
2261 | folio_put(src_folio); | |
2262 | return err; | |
2263 | } | |
2264 | #endif /* CONFIG_USERFAULTFD */ | |
2265 | ||
025c5b24 | 2266 | /* |
8f19b0c0 | 2267 | * Returns page table lock pointer if a given pmd maps a thp, NULL otherwise. |
025c5b24 | 2268 | * |
8f19b0c0 HY |
2269 | * Note that if it returns page table lock pointer, this routine returns without |
2270 | * unlocking page table lock. So callers must unlock it. | |
025c5b24 | 2271 | */ |
b6ec57f4 | 2272 | spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) |
025c5b24 | 2273 | { |
b6ec57f4 KS |
2274 | spinlock_t *ptl; |
2275 | ptl = pmd_lock(vma->vm_mm, pmd); | |
84c3fc4e ZY |
2276 | if (likely(is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || |
2277 | pmd_devmap(*pmd))) | |
b6ec57f4 KS |
2278 | return ptl; |
2279 | spin_unlock(ptl); | |
2280 | return NULL; | |
cd7548ab JW |
2281 | } |
2282 | ||
a00cc7d9 | 2283 | /* |
d965e390 | 2284 | * Returns page table lock pointer if a given pud maps a thp, NULL otherwise. |
a00cc7d9 | 2285 | * |
d965e390 ML |
2286 | * Note that if it returns page table lock pointer, this routine returns without |
2287 | * unlocking page table lock. So callers must unlock it. | |
a00cc7d9 MW |
2288 | */ |
2289 | spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma) | |
2290 | { | |
2291 | spinlock_t *ptl; | |
2292 | ||
2293 | ptl = pud_lock(vma->vm_mm, pud); | |
2294 | if (likely(pud_trans_huge(*pud) || pud_devmap(*pud))) | |
2295 | return ptl; | |
2296 | spin_unlock(ptl); | |
2297 | return NULL; | |
2298 | } | |
2299 | ||
2300 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD | |
2301 | int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, | |
2302 | pud_t *pud, unsigned long addr) | |
2303 | { | |
a00cc7d9 MW |
2304 | spinlock_t *ptl; |
2305 | ||
2306 | ptl = __pud_trans_huge_lock(pud, vma); | |
2307 | if (!ptl) | |
2308 | return 0; | |
74929079 | 2309 | |
f32928ab | 2310 | pudp_huge_get_and_clear_full(vma, addr, pud, tlb->fullmm); |
a00cc7d9 | 2311 | tlb_remove_pud_tlb_entry(tlb, pud, addr); |
2484ca9b | 2312 | if (vma_is_special_huge(vma)) { |
a00cc7d9 MW |
2313 | spin_unlock(ptl); |
2314 | /* No zero page support yet */ | |
2315 | } else { | |
2316 | /* No support for anonymous PUD pages yet */ | |
2317 | BUG(); | |
2318 | } | |
2319 | return 1; | |
2320 | } | |
2321 | ||
2322 | static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud, | |
2323 | unsigned long haddr) | |
2324 | { | |
2325 | VM_BUG_ON(haddr & ~HPAGE_PUD_MASK); | |
2326 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); | |
2327 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma); | |
2328 | VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud)); | |
2329 | ||
ce9311cf | 2330 | count_vm_event(THP_SPLIT_PUD); |
a00cc7d9 | 2331 | |
ec8832d0 | 2332 | pudp_huge_clear_flush(vma, haddr, pud); |
a00cc7d9 MW |
2333 | } |
2334 | ||
2335 | void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud, | |
2336 | unsigned long address) | |
2337 | { | |
2338 | spinlock_t *ptl; | |
ac46d4f3 | 2339 | struct mmu_notifier_range range; |
a00cc7d9 | 2340 | |
7d4a8be0 | 2341 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
6f4f13e8 | 2342 | address & HPAGE_PUD_MASK, |
ac46d4f3 JG |
2343 | (address & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE); |
2344 | mmu_notifier_invalidate_range_start(&range); | |
2345 | ptl = pud_lock(vma->vm_mm, pud); | |
a00cc7d9 MW |
2346 | if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud))) |
2347 | goto out; | |
ac46d4f3 | 2348 | __split_huge_pud_locked(vma, pud, range.start); |
a00cc7d9 MW |
2349 | |
2350 | out: | |
2351 | spin_unlock(ptl); | |
ec8832d0 | 2352 | mmu_notifier_invalidate_range_end(&range); |
a00cc7d9 MW |
2353 | } |
2354 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ | |
2355 | ||
eef1b3ba KS |
2356 | static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, |
2357 | unsigned long haddr, pmd_t *pmd) | |
2358 | { | |
2359 | struct mm_struct *mm = vma->vm_mm; | |
2360 | pgtable_t pgtable; | |
42b2af2c | 2361 | pmd_t _pmd, old_pmd; |
c9c1ee20 HD |
2362 | unsigned long addr; |
2363 | pte_t *pte; | |
eef1b3ba KS |
2364 | int i; |
2365 | ||
0f10851e JG |
2366 | /* |
2367 | * Leave pmd empty until pte is filled note that it is fine to delay | |
2368 | * notification until mmu_notifier_invalidate_range_end() as we are | |
2369 | * replacing a zero pmd write protected page with a zero pte write | |
2370 | * protected page. | |
2371 | * | |
ee65728e | 2372 | * See Documentation/mm/mmu_notifier.rst |
0f10851e | 2373 | */ |
42b2af2c | 2374 | old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd); |
eef1b3ba KS |
2375 | |
2376 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); | |
2377 | pmd_populate(mm, &_pmd, pgtable); | |
2378 | ||
c9c1ee20 HD |
2379 | pte = pte_offset_map(&_pmd, haddr); |
2380 | VM_BUG_ON(!pte); | |
2381 | for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { | |
2382 | pte_t entry; | |
2383 | ||
2384 | entry = pfn_pte(my_zero_pfn(addr), vma->vm_page_prot); | |
eef1b3ba | 2385 | entry = pte_mkspecial(entry); |
42b2af2c DH |
2386 | if (pmd_uffd_wp(old_pmd)) |
2387 | entry = pte_mkuffd_wp(entry); | |
c33c7948 | 2388 | VM_BUG_ON(!pte_none(ptep_get(pte))); |
c9c1ee20 HD |
2389 | set_pte_at(mm, addr, pte, entry); |
2390 | pte++; | |
eef1b3ba | 2391 | } |
c9c1ee20 | 2392 | pte_unmap(pte - 1); |
eef1b3ba KS |
2393 | smp_wmb(); /* make pte visible before pmd */ |
2394 | pmd_populate(mm, pmd, pgtable); | |
eef1b3ba KS |
2395 | } |
2396 | ||
2397 | static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, | |
ba988280 | 2398 | unsigned long haddr, bool freeze) |
eef1b3ba KS |
2399 | { |
2400 | struct mm_struct *mm = vma->vm_mm; | |
91b2978a | 2401 | struct folio *folio; |
eef1b3ba KS |
2402 | struct page *page; |
2403 | pgtable_t pgtable; | |
423ac9af | 2404 | pmd_t old_pmd, _pmd; |
292924b2 | 2405 | bool young, write, soft_dirty, pmd_migration = false, uffd_wp = false; |
0ccf7f16 | 2406 | bool anon_exclusive = false, dirty = false; |
2ac015e2 | 2407 | unsigned long addr; |
c9c1ee20 | 2408 | pte_t *pte; |
eef1b3ba KS |
2409 | int i; |
2410 | ||
2411 | VM_BUG_ON(haddr & ~HPAGE_PMD_MASK); | |
2412 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); | |
2413 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PMD_SIZE, vma); | |
84c3fc4e ZY |
2414 | VM_BUG_ON(!is_pmd_migration_entry(*pmd) && !pmd_trans_huge(*pmd) |
2415 | && !pmd_devmap(*pmd)); | |
eef1b3ba KS |
2416 | |
2417 | count_vm_event(THP_SPLIT_PMD); | |
2418 | ||
d21b9e57 | 2419 | if (!vma_is_anonymous(vma)) { |
ec8832d0 | 2420 | old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd); |
953c66c2 AK |
2421 | /* |
2422 | * We are going to unmap this huge page. So | |
2423 | * just go ahead and zap it | |
2424 | */ | |
2425 | if (arch_needs_pgtable_deposit()) | |
2426 | zap_deposited_table(mm, pmd); | |
2484ca9b | 2427 | if (vma_is_special_huge(vma)) |
d21b9e57 | 2428 | return; |
99fa8a48 HD |
2429 | if (unlikely(is_pmd_migration_entry(old_pmd))) { |
2430 | swp_entry_t entry; | |
2431 | ||
2432 | entry = pmd_to_swp_entry(old_pmd); | |
af5cdaf8 | 2433 | page = pfn_swap_entry_to_page(entry); |
99fa8a48 HD |
2434 | } else { |
2435 | page = pmd_page(old_pmd); | |
2436 | if (!PageDirty(page) && pmd_dirty(old_pmd)) | |
2437 | set_page_dirty(page); | |
2438 | if (!PageReferenced(page) && pmd_young(old_pmd)) | |
2439 | SetPageReferenced(page); | |
cea86fe2 | 2440 | page_remove_rmap(page, vma, true); |
99fa8a48 HD |
2441 | put_page(page); |
2442 | } | |
fadae295 | 2443 | add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR); |
eef1b3ba | 2444 | return; |
99fa8a48 HD |
2445 | } |
2446 | ||
3b77e8c8 | 2447 | if (is_huge_zero_pmd(*pmd)) { |
4645b9fe JG |
2448 | /* |
2449 | * FIXME: Do we want to invalidate secondary mmu by calling | |
1af5a810 AP |
2450 | * mmu_notifier_arch_invalidate_secondary_tlbs() see comments below |
2451 | * inside __split_huge_pmd() ? | |
4645b9fe JG |
2452 | * |
2453 | * We are going from a zero huge page write protected to zero | |
2454 | * small page also write protected so it does not seems useful | |
2455 | * to invalidate secondary mmu at this time. | |
2456 | */ | |
eef1b3ba KS |
2457 | return __split_huge_zero_page_pmd(vma, haddr, pmd); |
2458 | } | |
2459 | ||
423ac9af AK |
2460 | /* |
2461 | * Up to this point the pmd is present and huge and userland has the | |
2462 | * whole access to the hugepage during the split (which happens in | |
2463 | * place). If we overwrite the pmd with the not-huge version pointing | |
2464 | * to the pte here (which of course we could if all CPUs were bug | |
2465 | * free), userland could trigger a small page size TLB miss on the | |
2466 | * small sized TLB while the hugepage TLB entry is still established in | |
2467 | * the huge TLB. Some CPU doesn't like that. | |
42742d9b AK |
2468 | * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum |
2469 | * 383 on page 105. Intel should be safe but is also warns that it's | |
423ac9af AK |
2470 | * only safe if the permission and cache attributes of the two entries |
2471 | * loaded in the two TLB is identical (which should be the case here). | |
2472 | * But it is generally safer to never allow small and huge TLB entries | |
2473 | * for the same virtual address to be loaded simultaneously. So instead | |
2474 | * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the | |
2475 | * current pmd notpresent (atomically because here the pmd_trans_huge | |
2476 | * must remain set at all times on the pmd until the split is complete | |
2477 | * for this pmd), then we flush the SMP TLB and finally we write the | |
2478 | * non-huge version of the pmd entry with pmd_populate. | |
2479 | */ | |
2480 | old_pmd = pmdp_invalidate(vma, haddr, pmd); | |
2481 | ||
423ac9af | 2482 | pmd_migration = is_pmd_migration_entry(old_pmd); |
2e83ee1d | 2483 | if (unlikely(pmd_migration)) { |
84c3fc4e ZY |
2484 | swp_entry_t entry; |
2485 | ||
423ac9af | 2486 | entry = pmd_to_swp_entry(old_pmd); |
af5cdaf8 | 2487 | page = pfn_swap_entry_to_page(entry); |
4dd845b5 | 2488 | write = is_writable_migration_entry(entry); |
6c287605 DH |
2489 | if (PageAnon(page)) |
2490 | anon_exclusive = is_readable_exclusive_migration_entry(entry); | |
2e346877 PX |
2491 | young = is_migration_entry_young(entry); |
2492 | dirty = is_migration_entry_dirty(entry); | |
2e83ee1d | 2493 | soft_dirty = pmd_swp_soft_dirty(old_pmd); |
f45ec5ff | 2494 | uffd_wp = pmd_swp_uffd_wp(old_pmd); |
2e83ee1d | 2495 | } else { |
423ac9af | 2496 | page = pmd_page(old_pmd); |
91b2978a | 2497 | folio = page_folio(page); |
0ccf7f16 PX |
2498 | if (pmd_dirty(old_pmd)) { |
2499 | dirty = true; | |
91b2978a | 2500 | folio_set_dirty(folio); |
0ccf7f16 | 2501 | } |
2e83ee1d PX |
2502 | write = pmd_write(old_pmd); |
2503 | young = pmd_young(old_pmd); | |
2504 | soft_dirty = pmd_soft_dirty(old_pmd); | |
292924b2 | 2505 | uffd_wp = pmd_uffd_wp(old_pmd); |
6c287605 | 2506 | |
91b2978a DH |
2507 | VM_WARN_ON_FOLIO(!folio_ref_count(folio), folio); |
2508 | VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio); | |
6c287605 DH |
2509 | |
2510 | /* | |
2511 | * Without "freeze", we'll simply split the PMD, propagating the | |
2512 | * PageAnonExclusive() flag for each PTE by setting it for | |
2513 | * each subpage -- no need to (temporarily) clear. | |
2514 | * | |
2515 | * With "freeze" we want to replace mapped pages by | |
2516 | * migration entries right away. This is only possible if we | |
2517 | * managed to clear PageAnonExclusive() -- see | |
2518 | * set_pmd_migration_entry(). | |
2519 | * | |
2520 | * In case we cannot clear PageAnonExclusive(), split the PMD | |
2521 | * only and let try_to_migrate_one() fail later. | |
088b8aa5 DH |
2522 | * |
2523 | * See page_try_share_anon_rmap(): invalidate PMD first. | |
6c287605 | 2524 | */ |
91b2978a | 2525 | anon_exclusive = PageAnonExclusive(page); |
6c287605 DH |
2526 | if (freeze && anon_exclusive && page_try_share_anon_rmap(page)) |
2527 | freeze = false; | |
91b2978a DH |
2528 | if (!freeze) { |
2529 | rmap_t rmap_flags = RMAP_NONE; | |
2530 | ||
2531 | folio_ref_add(folio, HPAGE_PMD_NR - 1); | |
2532 | if (anon_exclusive) | |
2533 | rmap_flags |= RMAP_EXCLUSIVE; | |
2534 | folio_add_anon_rmap_ptes(folio, page, HPAGE_PMD_NR, | |
2535 | vma, haddr, rmap_flags); | |
2536 | } | |
2e83ee1d | 2537 | } |
eef1b3ba | 2538 | |
423ac9af AK |
2539 | /* |
2540 | * Withdraw the table only after we mark the pmd entry invalid. | |
2541 | * This's critical for some architectures (Power). | |
2542 | */ | |
eef1b3ba KS |
2543 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); |
2544 | pmd_populate(mm, &_pmd, pgtable); | |
2545 | ||
c9c1ee20 HD |
2546 | pte = pte_offset_map(&_pmd, haddr); |
2547 | VM_BUG_ON(!pte); | |
2ac015e2 | 2548 | for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { |
c9c1ee20 | 2549 | pte_t entry; |
eef1b3ba KS |
2550 | /* |
2551 | * Note that NUMA hinting access restrictions are not | |
2552 | * transferred to avoid any possibility of altering | |
2553 | * permissions across VMAs. | |
2554 | */ | |
84c3fc4e | 2555 | if (freeze || pmd_migration) { |
ba988280 | 2556 | swp_entry_t swp_entry; |
4dd845b5 AP |
2557 | if (write) |
2558 | swp_entry = make_writable_migration_entry( | |
2559 | page_to_pfn(page + i)); | |
6c287605 DH |
2560 | else if (anon_exclusive) |
2561 | swp_entry = make_readable_exclusive_migration_entry( | |
2562 | page_to_pfn(page + i)); | |
4dd845b5 AP |
2563 | else |
2564 | swp_entry = make_readable_migration_entry( | |
2565 | page_to_pfn(page + i)); | |
2e346877 PX |
2566 | if (young) |
2567 | swp_entry = make_migration_entry_young(swp_entry); | |
2568 | if (dirty) | |
2569 | swp_entry = make_migration_entry_dirty(swp_entry); | |
ba988280 | 2570 | entry = swp_entry_to_pte(swp_entry); |
804dd150 AA |
2571 | if (soft_dirty) |
2572 | entry = pte_swp_mksoft_dirty(entry); | |
f45ec5ff PX |
2573 | if (uffd_wp) |
2574 | entry = pte_swp_mkuffd_wp(entry); | |
ba988280 | 2575 | } else { |
6d2329f8 | 2576 | entry = mk_pte(page + i, READ_ONCE(vma->vm_page_prot)); |
1462c52e | 2577 | if (write) |
161e393c | 2578 | entry = pte_mkwrite(entry, vma); |
ba988280 KS |
2579 | if (!young) |
2580 | entry = pte_mkold(entry); | |
e833bc50 PX |
2581 | /* NOTE: this may set soft-dirty too on some archs */ |
2582 | if (dirty) | |
2583 | entry = pte_mkdirty(entry); | |
804dd150 AA |
2584 | if (soft_dirty) |
2585 | entry = pte_mksoft_dirty(entry); | |
292924b2 PX |
2586 | if (uffd_wp) |
2587 | entry = pte_mkuffd_wp(entry); | |
ba988280 | 2588 | } |
c33c7948 | 2589 | VM_BUG_ON(!pte_none(ptep_get(pte))); |
2ac015e2 | 2590 | set_pte_at(mm, addr, pte, entry); |
c9c1ee20 | 2591 | pte++; |
eef1b3ba | 2592 | } |
c9c1ee20 | 2593 | pte_unmap(pte - 1); |
eef1b3ba | 2594 | |
cb67f428 HD |
2595 | if (!pmd_migration) |
2596 | page_remove_rmap(page, vma, true); | |
96d82deb HD |
2597 | if (freeze) |
2598 | put_page(page); | |
eef1b3ba KS |
2599 | |
2600 | smp_wmb(); /* make pte visible before pmd */ | |
2601 | pmd_populate(mm, pmd, pgtable); | |
2602 | } | |
2603 | ||
2604 | void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, | |
af28a988 | 2605 | unsigned long address, bool freeze, struct folio *folio) |
eef1b3ba KS |
2606 | { |
2607 | spinlock_t *ptl; | |
ac46d4f3 | 2608 | struct mmu_notifier_range range; |
eef1b3ba | 2609 | |
7d4a8be0 | 2610 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
6f4f13e8 | 2611 | address & HPAGE_PMD_MASK, |
ac46d4f3 JG |
2612 | (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE); |
2613 | mmu_notifier_invalidate_range_start(&range); | |
2614 | ptl = pmd_lock(vma->vm_mm, pmd); | |
33f4751e NH |
2615 | |
2616 | /* | |
af28a988 MWO |
2617 | * If caller asks to setup a migration entry, we need a folio to check |
2618 | * pmd against. Otherwise we can end up replacing wrong folio. | |
33f4751e | 2619 | */ |
af28a988 | 2620 | VM_BUG_ON(freeze && !folio); |
83a8441f | 2621 | VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); |
33f4751e | 2622 | |
7f760917 | 2623 | if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || |
83a8441f | 2624 | is_pmd_migration_entry(*pmd)) { |
cea33328 ML |
2625 | /* |
2626 | * It's safe to call pmd_page when folio is set because it's | |
2627 | * guaranteed that pmd is present. | |
2628 | */ | |
83a8441f MWO |
2629 | if (folio && folio != page_folio(pmd_page(*pmd))) |
2630 | goto out; | |
7f760917 | 2631 | __split_huge_pmd_locked(vma, pmd, range.start, freeze); |
83a8441f | 2632 | } |
7f760917 | 2633 | |
e90309c9 | 2634 | out: |
eef1b3ba | 2635 | spin_unlock(ptl); |
ec8832d0 | 2636 | mmu_notifier_invalidate_range_end(&range); |
eef1b3ba KS |
2637 | } |
2638 | ||
fec89c10 | 2639 | void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, |
af28a988 | 2640 | bool freeze, struct folio *folio) |
94fcc585 | 2641 | { |
50722804 | 2642 | pmd_t *pmd = mm_find_pmd(vma->vm_mm, address); |
94fcc585 | 2643 | |
50722804 | 2644 | if (!pmd) |
f72e7dcd HD |
2645 | return; |
2646 | ||
af28a988 | 2647 | __split_huge_pmd(vma, pmd, address, freeze, folio); |
94fcc585 AA |
2648 | } |
2649 | ||
71f9e58e ML |
2650 | static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address) |
2651 | { | |
2652 | /* | |
2653 | * If the new address isn't hpage aligned and it could previously | |
2654 | * contain an hugepage: check if we need to split an huge pmd. | |
2655 | */ | |
2656 | if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) && | |
2657 | range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE), | |
2658 | ALIGN(address, HPAGE_PMD_SIZE))) | |
2659 | split_huge_pmd_address(vma, address, false, NULL); | |
2660 | } | |
2661 | ||
e1b9996b | 2662 | void vma_adjust_trans_huge(struct vm_area_struct *vma, |
94fcc585 AA |
2663 | unsigned long start, |
2664 | unsigned long end, | |
2665 | long adjust_next) | |
2666 | { | |
71f9e58e ML |
2667 | /* Check if we need to split start first. */ |
2668 | split_huge_pmd_if_needed(vma, start); | |
94fcc585 | 2669 | |
71f9e58e ML |
2670 | /* Check if we need to split end next. */ |
2671 | split_huge_pmd_if_needed(vma, end); | |
94fcc585 AA |
2672 | |
2673 | /* | |
68540502 | 2674 | * If we're also updating the next vma vm_start, |
71f9e58e | 2675 | * check if we need to split it. |
94fcc585 AA |
2676 | */ |
2677 | if (adjust_next > 0) { | |
68540502 | 2678 | struct vm_area_struct *next = find_vma(vma->vm_mm, vma->vm_end); |
94fcc585 | 2679 | unsigned long nstart = next->vm_start; |
f9d86a60 | 2680 | nstart += adjust_next; |
71f9e58e | 2681 | split_huge_pmd_if_needed(next, nstart); |
94fcc585 AA |
2682 | } |
2683 | } | |
e9b61f19 | 2684 | |
684555aa | 2685 | static void unmap_folio(struct folio *folio) |
e9b61f19 | 2686 | { |
a98a2f0c | 2687 | enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD | |
3027c6f8 | 2688 | TTU_SYNC | TTU_BATCH_FLUSH; |
e9b61f19 | 2689 | |
684555aa | 2690 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
e9b61f19 | 2691 | |
a98a2f0c AP |
2692 | /* |
2693 | * Anon pages need migration entries to preserve them, but file | |
2694 | * pages can simply be left unmapped, then faulted back on demand. | |
2695 | * If that is ever changed (perhaps for mlock), update remap_page(). | |
2696 | */ | |
4b8554c5 MWO |
2697 | if (folio_test_anon(folio)) |
2698 | try_to_migrate(folio, ttu_flags); | |
a98a2f0c | 2699 | else |
869f7ee6 | 2700 | try_to_unmap(folio, ttu_flags | TTU_IGNORE_MLOCK); |
3027c6f8 BW |
2701 | |
2702 | try_to_unmap_flush(); | |
e9b61f19 KS |
2703 | } |
2704 | ||
4eecb8b9 | 2705 | static void remap_page(struct folio *folio, unsigned long nr) |
e9b61f19 | 2706 | { |
4eecb8b9 | 2707 | int i = 0; |
ab02c252 | 2708 | |
684555aa | 2709 | /* If unmap_folio() uses try_to_migrate() on file, remove this check */ |
4eecb8b9 | 2710 | if (!folio_test_anon(folio)) |
ab02c252 | 2711 | return; |
4eecb8b9 MWO |
2712 | for (;;) { |
2713 | remove_migration_ptes(folio, folio, true); | |
2714 | i += folio_nr_pages(folio); | |
2715 | if (i >= nr) | |
2716 | break; | |
2717 | folio = folio_next(folio); | |
ace71a19 | 2718 | } |
e9b61f19 KS |
2719 | } |
2720 | ||
94866635 | 2721 | static void lru_add_page_tail(struct page *head, struct page *tail, |
88dcb9a3 AS |
2722 | struct lruvec *lruvec, struct list_head *list) |
2723 | { | |
94866635 AS |
2724 | VM_BUG_ON_PAGE(!PageHead(head), head); |
2725 | VM_BUG_ON_PAGE(PageCompound(tail), head); | |
2726 | VM_BUG_ON_PAGE(PageLRU(tail), head); | |
6168d0da | 2727 | lockdep_assert_held(&lruvec->lru_lock); |
88dcb9a3 | 2728 | |
6dbb5741 | 2729 | if (list) { |
88dcb9a3 | 2730 | /* page reclaim is reclaiming a huge page */ |
6dbb5741 | 2731 | VM_WARN_ON(PageLRU(head)); |
94866635 AS |
2732 | get_page(tail); |
2733 | list_add_tail(&tail->lru, list); | |
88dcb9a3 | 2734 | } else { |
6dbb5741 AS |
2735 | /* head is still on lru (and we have it frozen) */ |
2736 | VM_WARN_ON(!PageLRU(head)); | |
07ca7606 HD |
2737 | if (PageUnevictable(tail)) |
2738 | tail->mlock_count = 0; | |
2739 | else | |
2740 | list_add_tail(&tail->lru, &head->lru); | |
6dbb5741 | 2741 | SetPageLRU(tail); |
88dcb9a3 AS |
2742 | } |
2743 | } | |
2744 | ||
07e09c48 | 2745 | static void __split_huge_page_tail(struct folio *folio, int tail, |
e9b61f19 KS |
2746 | struct lruvec *lruvec, struct list_head *list) |
2747 | { | |
07e09c48 | 2748 | struct page *head = &folio->page; |
e9b61f19 | 2749 | struct page *page_tail = head + tail; |
07e09c48 DH |
2750 | /* |
2751 | * Careful: new_folio is not a "real" folio before we cleared PageTail. | |
2752 | * Don't pass it around before clear_compound_head(). | |
2753 | */ | |
2754 | struct folio *new_folio = (struct folio *)page_tail; | |
e9b61f19 | 2755 | |
8df651c7 | 2756 | VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail); |
e9b61f19 KS |
2757 | |
2758 | /* | |
605ca5ed KK |
2759 | * Clone page flags before unfreezing refcount. |
2760 | * | |
2761 | * After successful get_page_unless_zero() might follow flags change, | |
8958b249 | 2762 | * for example lock_page() which set PG_waiters. |
6c287605 DH |
2763 | * |
2764 | * Note that for mapped sub-pages of an anonymous THP, | |
684555aa | 2765 | * PG_anon_exclusive has been cleared in unmap_folio() and is stored in |
6c287605 DH |
2766 | * the migration entry instead from where remap_page() will restore it. |
2767 | * We can still have PG_anon_exclusive set on effectively unmapped and | |
2768 | * unreferenced sub-pages of an anonymous THP: we can simply drop | |
2769 | * PG_anon_exclusive (-> PG_mappedtodisk) for these here. | |
e9b61f19 | 2770 | */ |
e9b61f19 KS |
2771 | page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
2772 | page_tail->flags |= (head->flags & | |
2773 | ((1L << PG_referenced) | | |
2774 | (1L << PG_swapbacked) | | |
38d8b4e6 | 2775 | (1L << PG_swapcache) | |
e9b61f19 KS |
2776 | (1L << PG_mlocked) | |
2777 | (1L << PG_uptodate) | | |
2778 | (1L << PG_active) | | |
1899ad18 | 2779 | (1L << PG_workingset) | |
e9b61f19 | 2780 | (1L << PG_locked) | |
b8d3c4c3 | 2781 | (1L << PG_unevictable) | |
b0284cd2 | 2782 | #ifdef CONFIG_ARCH_USES_PG_ARCH_X |
72e6afa0 | 2783 | (1L << PG_arch_2) | |
ef6458b1 | 2784 | (1L << PG_arch_3) | |
72e6afa0 | 2785 | #endif |
ec1c86b2 YZ |
2786 | (1L << PG_dirty) | |
2787 | LRU_GEN_MASK | LRU_REFS_MASK)); | |
e9b61f19 | 2788 | |
cb67f428 | 2789 | /* ->mapping in first and second tail page is replaced by other uses */ |
173d9d9f HD |
2790 | VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING, |
2791 | page_tail); | |
2792 | page_tail->mapping = head->mapping; | |
2793 | page_tail->index = head->index + tail; | |
71e2d666 MG |
2794 | |
2795 | /* | |
cfeed8ff DH |
2796 | * page->private should not be set in tail pages. Fix up and warn once |
2797 | * if private is unexpectedly set. | |
71e2d666 | 2798 | */ |
cfeed8ff DH |
2799 | if (unlikely(page_tail->private)) { |
2800 | VM_WARN_ON_ONCE_PAGE(true, page_tail); | |
71e2d666 MG |
2801 | page_tail->private = 0; |
2802 | } | |
07e09c48 DH |
2803 | if (folio_test_swapcache(folio)) |
2804 | new_folio->swap.val = folio->swap.val + tail; | |
173d9d9f | 2805 | |
605ca5ed | 2806 | /* Page flags must be visible before we make the page non-compound. */ |
e9b61f19 KS |
2807 | smp_wmb(); |
2808 | ||
605ca5ed KK |
2809 | /* |
2810 | * Clear PageTail before unfreezing page refcount. | |
2811 | * | |
2812 | * After successful get_page_unless_zero() might follow put_page() | |
2813 | * which needs correct compound_head(). | |
2814 | */ | |
e9b61f19 KS |
2815 | clear_compound_head(page_tail); |
2816 | ||
605ca5ed | 2817 | /* Finally unfreeze refcount. Additional reference from page cache. */ |
b7542769 KW |
2818 | page_ref_unfreeze(page_tail, 1 + (!folio_test_anon(folio) || |
2819 | folio_test_swapcache(folio))); | |
605ca5ed | 2820 | |
b7542769 KW |
2821 | if (folio_test_young(folio)) |
2822 | folio_set_young(new_folio); | |
2823 | if (folio_test_idle(folio)) | |
2824 | folio_set_idle(new_folio); | |
e9b61f19 | 2825 | |
c8253011 | 2826 | folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio)); |
94723aaf MH |
2827 | |
2828 | /* | |
2829 | * always add to the tail because some iterators expect new | |
2830 | * pages to show after the currently processed elements - e.g. | |
2831 | * migrate_pages | |
2832 | */ | |
e9b61f19 | 2833 | lru_add_page_tail(head, page_tail, lruvec, list); |
e9b61f19 KS |
2834 | } |
2835 | ||
baa355fd | 2836 | static void __split_huge_page(struct page *page, struct list_head *list, |
b6769834 | 2837 | pgoff_t end) |
e9b61f19 | 2838 | { |
e809c3fe MWO |
2839 | struct folio *folio = page_folio(page); |
2840 | struct page *head = &folio->page; | |
e9b61f19 | 2841 | struct lruvec *lruvec; |
4101196b MWO |
2842 | struct address_space *swap_cache = NULL; |
2843 | unsigned long offset = 0; | |
8cce5475 | 2844 | unsigned int nr = thp_nr_pages(head); |
509f0069 | 2845 | int i, nr_dropped = 0; |
e9b61f19 | 2846 | |
e9b61f19 | 2847 | /* complete memcg works before add pages to LRU */ |
be6c8982 | 2848 | split_page_memcg(head, nr); |
e9b61f19 | 2849 | |
07e09c48 DH |
2850 | if (folio_test_anon(folio) && folio_test_swapcache(folio)) { |
2851 | offset = swp_offset(folio->swap); | |
2852 | swap_cache = swap_address_space(folio->swap); | |
4101196b MWO |
2853 | xa_lock(&swap_cache->i_pages); |
2854 | } | |
2855 | ||
f0953a1b | 2856 | /* lock lru list/PageCompound, ref frozen by page_ref_freeze */ |
e809c3fe | 2857 | lruvec = folio_lruvec_lock(folio); |
b6769834 | 2858 | |
eac96c3e YS |
2859 | ClearPageHasHWPoisoned(head); |
2860 | ||
8cce5475 | 2861 | for (i = nr - 1; i >= 1; i--) { |
07e09c48 | 2862 | __split_huge_page_tail(folio, i, lruvec, list); |
d144bf62 | 2863 | /* Some pages can be beyond EOF: drop them from page cache */ |
baa355fd | 2864 | if (head[i].index >= end) { |
fb5c2029 MWO |
2865 | struct folio *tail = page_folio(head + i); |
2866 | ||
d144bf62 | 2867 | if (shmem_mapping(head->mapping)) |
509f0069 | 2868 | nr_dropped++; |
fb5c2029 MWO |
2869 | else if (folio_test_clear_dirty(tail)) |
2870 | folio_account_cleaned(tail, | |
2871 | inode_to_wb(folio->mapping->host)); | |
2872 | __filemap_remove_folio(tail, NULL); | |
2873 | folio_put(tail); | |
4101196b MWO |
2874 | } else if (!PageAnon(page)) { |
2875 | __xa_store(&head->mapping->i_pages, head[i].index, | |
2876 | head + i, 0); | |
2877 | } else if (swap_cache) { | |
2878 | __xa_store(&swap_cache->i_pages, offset + i, | |
2879 | head + i, 0); | |
baa355fd KS |
2880 | } |
2881 | } | |
e9b61f19 KS |
2882 | |
2883 | ClearPageCompound(head); | |
6168d0da | 2884 | unlock_page_lruvec(lruvec); |
b6769834 | 2885 | /* Caller disabled irqs, so they are still disabled here */ |
f7da677b | 2886 | |
8cce5475 | 2887 | split_page_owner(head, nr); |
f7da677b | 2888 | |
baa355fd KS |
2889 | /* See comment in __split_huge_page_tail() */ |
2890 | if (PageAnon(head)) { | |
aa5dc07f | 2891 | /* Additional pin to swap cache */ |
4101196b | 2892 | if (PageSwapCache(head)) { |
38d8b4e6 | 2893 | page_ref_add(head, 2); |
4101196b MWO |
2894 | xa_unlock(&swap_cache->i_pages); |
2895 | } else { | |
38d8b4e6 | 2896 | page_ref_inc(head); |
4101196b | 2897 | } |
baa355fd | 2898 | } else { |
aa5dc07f | 2899 | /* Additional pin to page cache */ |
baa355fd | 2900 | page_ref_add(head, 2); |
b93b0163 | 2901 | xa_unlock(&head->mapping->i_pages); |
baa355fd | 2902 | } |
b6769834 | 2903 | local_irq_enable(); |
e9b61f19 | 2904 | |
509f0069 HD |
2905 | if (nr_dropped) |
2906 | shmem_uncharge(head->mapping->host, nr_dropped); | |
4eecb8b9 | 2907 | remap_page(folio, nr); |
e9b61f19 | 2908 | |
07e09c48 DH |
2909 | if (folio_test_swapcache(folio)) |
2910 | split_swap_cluster(folio->swap); | |
c4f9c701 | 2911 | |
8cce5475 | 2912 | for (i = 0; i < nr; i++) { |
e9b61f19 KS |
2913 | struct page *subpage = head + i; |
2914 | if (subpage == page) | |
2915 | continue; | |
2916 | unlock_page(subpage); | |
2917 | ||
2918 | /* | |
2919 | * Subpages may be freed if there wasn't any mapping | |
2920 | * like if add_to_swap() is running on a lru page that | |
2921 | * had its mapping zapped. And freeing these pages | |
2922 | * requires taking the lru_lock so we do the put_page | |
2923 | * of the tail pages after the split is complete. | |
2924 | */ | |
0b175468 | 2925 | free_page_and_swap_cache(subpage); |
e9b61f19 KS |
2926 | } |
2927 | } | |
2928 | ||
b8f593cd | 2929 | /* Racy check whether the huge page can be split */ |
d4b4084a | 2930 | bool can_split_folio(struct folio *folio, int *pextra_pins) |
b8f593cd HY |
2931 | { |
2932 | int extra_pins; | |
2933 | ||
aa5dc07f | 2934 | /* Additional pins from page cache */ |
d4b4084a MWO |
2935 | if (folio_test_anon(folio)) |
2936 | extra_pins = folio_test_swapcache(folio) ? | |
2937 | folio_nr_pages(folio) : 0; | |
b8f593cd | 2938 | else |
d4b4084a | 2939 | extra_pins = folio_nr_pages(folio); |
b8f593cd HY |
2940 | if (pextra_pins) |
2941 | *pextra_pins = extra_pins; | |
d4b4084a | 2942 | return folio_mapcount(folio) == folio_ref_count(folio) - extra_pins - 1; |
b8f593cd HY |
2943 | } |
2944 | ||
e9b61f19 KS |
2945 | /* |
2946 | * This function splits huge page into normal pages. @page can point to any | |
2947 | * subpage of huge page to split. Split doesn't change the position of @page. | |
2948 | * | |
2949 | * Only caller must hold pin on the @page, otherwise split fails with -EBUSY. | |
2950 | * The huge page must be locked. | |
2951 | * | |
2952 | * If @list is null, tail pages will be added to LRU list, otherwise, to @list. | |
2953 | * | |
2954 | * Both head page and tail pages will inherit mapping, flags, and so on from | |
2955 | * the hugepage. | |
2956 | * | |
2957 | * GUP pin and PG_locked transferred to @page. Rest subpages can be freed if | |
2958 | * they are not mapped. | |
2959 | * | |
2960 | * Returns 0 if the hugepage is split successfully. | |
2961 | * Returns -EBUSY if the page is pinned or if anon_vma disappeared from under | |
2962 | * us. | |
2963 | */ | |
2964 | int split_huge_page_to_list(struct page *page, struct list_head *list) | |
2965 | { | |
4eecb8b9 | 2966 | struct folio *folio = page_folio(page); |
f8baa6be | 2967 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
3e9a13da | 2968 | XA_STATE(xas, &folio->mapping->i_pages, folio->index); |
baa355fd KS |
2969 | struct anon_vma *anon_vma = NULL; |
2970 | struct address_space *mapping = NULL; | |
504e070d | 2971 | int extra_pins, ret; |
006d3ff2 | 2972 | pgoff_t end; |
478d134e | 2973 | bool is_hzp; |
e9b61f19 | 2974 | |
3e9a13da MWO |
2975 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
2976 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); | |
e9b61f19 | 2977 | |
3e9a13da | 2978 | is_hzp = is_huge_zero_page(&folio->page); |
4737edbb NH |
2979 | if (is_hzp) { |
2980 | pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); | |
478d134e | 2981 | return -EBUSY; |
4737edbb | 2982 | } |
478d134e | 2983 | |
3e9a13da | 2984 | if (folio_test_writeback(folio)) |
59807685 HY |
2985 | return -EBUSY; |
2986 | ||
3e9a13da | 2987 | if (folio_test_anon(folio)) { |
baa355fd | 2988 | /* |
c1e8d7c6 | 2989 | * The caller does not necessarily hold an mmap_lock that would |
baa355fd KS |
2990 | * prevent the anon_vma disappearing so we first we take a |
2991 | * reference to it and then lock the anon_vma for write. This | |
2f031c6f | 2992 | * is similar to folio_lock_anon_vma_read except the write lock |
baa355fd KS |
2993 | * is taken to serialise against parallel split or collapse |
2994 | * operations. | |
2995 | */ | |
29eea9b5 | 2996 | anon_vma = folio_get_anon_vma(folio); |
baa355fd KS |
2997 | if (!anon_vma) { |
2998 | ret = -EBUSY; | |
2999 | goto out; | |
3000 | } | |
006d3ff2 | 3001 | end = -1; |
baa355fd KS |
3002 | mapping = NULL; |
3003 | anon_vma_lock_write(anon_vma); | |
3004 | } else { | |
6a3edd29 YF |
3005 | gfp_t gfp; |
3006 | ||
3e9a13da | 3007 | mapping = folio->mapping; |
baa355fd KS |
3008 | |
3009 | /* Truncated ? */ | |
3010 | if (!mapping) { | |
3011 | ret = -EBUSY; | |
3012 | goto out; | |
3013 | } | |
3014 | ||
6a3edd29 YF |
3015 | gfp = current_gfp_context(mapping_gfp_mask(mapping) & |
3016 | GFP_RECLAIM_MASK); | |
3017 | ||
0201ebf2 | 3018 | if (!filemap_release_folio(folio, gfp)) { |
6a3edd29 YF |
3019 | ret = -EBUSY; |
3020 | goto out; | |
3021 | } | |
3022 | ||
3e9a13da | 3023 | xas_split_alloc(&xas, folio, folio_order(folio), gfp); |
6b24ca4a MWO |
3024 | if (xas_error(&xas)) { |
3025 | ret = xas_error(&xas); | |
3026 | goto out; | |
3027 | } | |
3028 | ||
baa355fd KS |
3029 | anon_vma = NULL; |
3030 | i_mmap_lock_read(mapping); | |
006d3ff2 HD |
3031 | |
3032 | /* | |
3033 | *__split_huge_page() may need to trim off pages beyond EOF: | |
3034 | * but on 32-bit, i_size_read() takes an irq-unsafe seqlock, | |
3035 | * which cannot be nested inside the page tree lock. So note | |
3036 | * end now: i_size itself may be changed at any moment, but | |
3e9a13da | 3037 | * folio lock is good enough to serialize the trimming. |
006d3ff2 HD |
3038 | */ |
3039 | end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE); | |
d144bf62 HD |
3040 | if (shmem_mapping(mapping)) |
3041 | end = shmem_fallocend(mapping->host, end); | |
e9b61f19 | 3042 | } |
e9b61f19 KS |
3043 | |
3044 | /* | |
684555aa | 3045 | * Racy check if we can split the page, before unmap_folio() will |
e9b61f19 KS |
3046 | * split PMDs |
3047 | */ | |
d4b4084a | 3048 | if (!can_split_folio(folio, &extra_pins)) { |
fd4a7ac3 | 3049 | ret = -EAGAIN; |
e9b61f19 KS |
3050 | goto out_unlock; |
3051 | } | |
3052 | ||
684555aa | 3053 | unmap_folio(folio); |
e9b61f19 | 3054 | |
b6769834 AS |
3055 | /* block interrupt reentry in xa_lock and spinlock */ |
3056 | local_irq_disable(); | |
baa355fd | 3057 | if (mapping) { |
baa355fd | 3058 | /* |
3e9a13da MWO |
3059 | * Check if the folio is present in page cache. |
3060 | * We assume all tail are present too, if folio is there. | |
baa355fd | 3061 | */ |
6b24ca4a MWO |
3062 | xas_lock(&xas); |
3063 | xas_reset(&xas); | |
3e9a13da | 3064 | if (xas_load(&xas) != folio) |
baa355fd KS |
3065 | goto fail; |
3066 | } | |
3067 | ||
0139aa7b | 3068 | /* Prevent deferred_split_scan() touching ->_refcount */ |
364c1eeb | 3069 | spin_lock(&ds_queue->split_queue_lock); |
3e9a13da | 3070 | if (folio_ref_freeze(folio, 1 + extra_pins)) { |
4375a553 | 3071 | if (!list_empty(&folio->_deferred_list)) { |
364c1eeb | 3072 | ds_queue->split_queue_len--; |
4375a553 | 3073 | list_del(&folio->_deferred_list); |
9a982250 | 3074 | } |
afb97172 | 3075 | spin_unlock(&ds_queue->split_queue_lock); |
06d3eff6 | 3076 | if (mapping) { |
3e9a13da | 3077 | int nr = folio_nr_pages(folio); |
bf9ecead | 3078 | |
3e9a13da | 3079 | xas_split(&xas, folio, folio_order(folio)); |
a48d5bdc SR |
3080 | if (folio_test_pmd_mappable(folio)) { |
3081 | if (folio_test_swapbacked(folio)) { | |
3082 | __lruvec_stat_mod_folio(folio, | |
3083 | NR_SHMEM_THPS, -nr); | |
3084 | } else { | |
3085 | __lruvec_stat_mod_folio(folio, | |
3086 | NR_FILE_THPS, -nr); | |
3087 | filemap_nr_thps_dec(mapping); | |
3088 | } | |
1ca7554d | 3089 | } |
06d3eff6 KS |
3090 | } |
3091 | ||
b6769834 | 3092 | __split_huge_page(page, list, end); |
c4f9c701 | 3093 | ret = 0; |
e9b61f19 | 3094 | } else { |
364c1eeb | 3095 | spin_unlock(&ds_queue->split_queue_lock); |
504e070d YS |
3096 | fail: |
3097 | if (mapping) | |
6b24ca4a | 3098 | xas_unlock(&xas); |
b6769834 | 3099 | local_irq_enable(); |
4eecb8b9 | 3100 | remap_page(folio, folio_nr_pages(folio)); |
fd4a7ac3 | 3101 | ret = -EAGAIN; |
e9b61f19 KS |
3102 | } |
3103 | ||
3104 | out_unlock: | |
baa355fd KS |
3105 | if (anon_vma) { |
3106 | anon_vma_unlock_write(anon_vma); | |
3107 | put_anon_vma(anon_vma); | |
3108 | } | |
3109 | if (mapping) | |
3110 | i_mmap_unlock_read(mapping); | |
e9b61f19 | 3111 | out: |
69a37a8b | 3112 | xas_destroy(&xas); |
e9b61f19 KS |
3113 | count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); |
3114 | return ret; | |
3115 | } | |
9a982250 | 3116 | |
8dc4a8f1 | 3117 | void folio_undo_large_rmappable(struct folio *folio) |
9a982250 | 3118 | { |
8dc4a8f1 | 3119 | struct deferred_split *ds_queue; |
9a982250 KS |
3120 | unsigned long flags; |
3121 | ||
deedad80 YF |
3122 | /* |
3123 | * At this point, there is no one trying to add the folio to | |
3124 | * deferred_list. If folio is not in deferred_list, it's safe | |
3125 | * to check without acquiring the split_queue_lock. | |
3126 | */ | |
8dc4a8f1 MWO |
3127 | if (data_race(list_empty(&folio->_deferred_list))) |
3128 | return; | |
3129 | ||
3130 | ds_queue = get_deferred_split_queue(folio); | |
3131 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); | |
3132 | if (!list_empty(&folio->_deferred_list)) { | |
3133 | ds_queue->split_queue_len--; | |
3134 | list_del(&folio->_deferred_list); | |
9a982250 | 3135 | } |
8dc4a8f1 | 3136 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 KS |
3137 | } |
3138 | ||
f158ed61 | 3139 | void deferred_split_folio(struct folio *folio) |
9a982250 | 3140 | { |
f8baa6be | 3141 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
87eaceb3 | 3142 | #ifdef CONFIG_MEMCG |
8991de90 | 3143 | struct mem_cgroup *memcg = folio_memcg(folio); |
87eaceb3 | 3144 | #endif |
9a982250 KS |
3145 | unsigned long flags; |
3146 | ||
8991de90 | 3147 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
9a982250 | 3148 | |
87eaceb3 YS |
3149 | /* |
3150 | * The try_to_unmap() in page reclaim path might reach here too, | |
3151 | * this may cause a race condition to corrupt deferred split queue. | |
8991de90 | 3152 | * And, if page reclaim is already handling the same folio, it is |
87eaceb3 YS |
3153 | * unnecessary to handle it again in shrinker. |
3154 | * | |
8991de90 MWO |
3155 | * Check the swapcache flag to determine if the folio is being |
3156 | * handled by page reclaim since THP swap would add the folio into | |
87eaceb3 YS |
3157 | * swap cache before calling try_to_unmap(). |
3158 | */ | |
8991de90 | 3159 | if (folio_test_swapcache(folio)) |
87eaceb3 YS |
3160 | return; |
3161 | ||
8991de90 | 3162 | if (!list_empty(&folio->_deferred_list)) |
87eaceb3 YS |
3163 | return; |
3164 | ||
364c1eeb | 3165 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
8991de90 | 3166 | if (list_empty(&folio->_deferred_list)) { |
f9719a03 | 3167 | count_vm_event(THP_DEFERRED_SPLIT_PAGE); |
8991de90 | 3168 | list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); |
364c1eeb | 3169 | ds_queue->split_queue_len++; |
87eaceb3 YS |
3170 | #ifdef CONFIG_MEMCG |
3171 | if (memcg) | |
8991de90 | 3172 | set_shrinker_bit(memcg, folio_nid(folio), |
54d91729 | 3173 | deferred_split_shrinker->id); |
87eaceb3 | 3174 | #endif |
9a982250 | 3175 | } |
364c1eeb | 3176 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 KS |
3177 | } |
3178 | ||
3179 | static unsigned long deferred_split_count(struct shrinker *shrink, | |
3180 | struct shrink_control *sc) | |
3181 | { | |
a3d0a918 | 3182 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
364c1eeb | 3183 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
87eaceb3 YS |
3184 | |
3185 | #ifdef CONFIG_MEMCG | |
3186 | if (sc->memcg) | |
3187 | ds_queue = &sc->memcg->deferred_split_queue; | |
3188 | #endif | |
364c1eeb | 3189 | return READ_ONCE(ds_queue->split_queue_len); |
9a982250 KS |
3190 | } |
3191 | ||
3192 | static unsigned long deferred_split_scan(struct shrinker *shrink, | |
3193 | struct shrink_control *sc) | |
3194 | { | |
a3d0a918 | 3195 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
364c1eeb | 3196 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
9a982250 | 3197 | unsigned long flags; |
4375a553 MWO |
3198 | LIST_HEAD(list); |
3199 | struct folio *folio, *next; | |
9a982250 KS |
3200 | int split = 0; |
3201 | ||
87eaceb3 YS |
3202 | #ifdef CONFIG_MEMCG |
3203 | if (sc->memcg) | |
3204 | ds_queue = &sc->memcg->deferred_split_queue; | |
3205 | #endif | |
3206 | ||
364c1eeb | 3207 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
9a982250 | 3208 | /* Take pin on all head pages to avoid freeing them under us */ |
4375a553 MWO |
3209 | list_for_each_entry_safe(folio, next, &ds_queue->split_queue, |
3210 | _deferred_list) { | |
3211 | if (folio_try_get(folio)) { | |
3212 | list_move(&folio->_deferred_list, &list); | |
e3ae1953 | 3213 | } else { |
4375a553 MWO |
3214 | /* We lost race with folio_put() */ |
3215 | list_del_init(&folio->_deferred_list); | |
364c1eeb | 3216 | ds_queue->split_queue_len--; |
9a982250 | 3217 | } |
e3ae1953 KS |
3218 | if (!--sc->nr_to_scan) |
3219 | break; | |
9a982250 | 3220 | } |
364c1eeb | 3221 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
9a982250 | 3222 | |
4375a553 MWO |
3223 | list_for_each_entry_safe(folio, next, &list, _deferred_list) { |
3224 | if (!folio_trylock(folio)) | |
fa41b900 | 3225 | goto next; |
9a982250 | 3226 | /* split_huge_page() removes page from list on success */ |
4375a553 | 3227 | if (!split_folio(folio)) |
9a982250 | 3228 | split++; |
4375a553 | 3229 | folio_unlock(folio); |
fa41b900 | 3230 | next: |
4375a553 | 3231 | folio_put(folio); |
9a982250 KS |
3232 | } |
3233 | ||
364c1eeb YS |
3234 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
3235 | list_splice_tail(&list, &ds_queue->split_queue); | |
3236 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); | |
9a982250 | 3237 | |
cb8d68ec KS |
3238 | /* |
3239 | * Stop shrinker if we didn't split any page, but the queue is empty. | |
3240 | * This can happen if pages were freed under us. | |
3241 | */ | |
364c1eeb | 3242 | if (!split && list_empty(&ds_queue->split_queue)) |
cb8d68ec KS |
3243 | return SHRINK_STOP; |
3244 | return split; | |
9a982250 KS |
3245 | } |
3246 | ||
49071d43 | 3247 | #ifdef CONFIG_DEBUG_FS |
fa6c0231 | 3248 | static void split_huge_pages_all(void) |
49071d43 KS |
3249 | { |
3250 | struct zone *zone; | |
3251 | struct page *page; | |
630e7c5e | 3252 | struct folio *folio; |
49071d43 KS |
3253 | unsigned long pfn, max_zone_pfn; |
3254 | unsigned long total = 0, split = 0; | |
3255 | ||
fa6c0231 | 3256 | pr_debug("Split all THPs\n"); |
a17206da ML |
3257 | for_each_zone(zone) { |
3258 | if (!managed_zone(zone)) | |
3259 | continue; | |
49071d43 KS |
3260 | max_zone_pfn = zone_end_pfn(zone); |
3261 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { | |
a17206da | 3262 | int nr_pages; |
49071d43 | 3263 | |
2b7aa91b | 3264 | page = pfn_to_online_page(pfn); |
630e7c5e KW |
3265 | if (!page || PageTail(page)) |
3266 | continue; | |
3267 | folio = page_folio(page); | |
3268 | if (!folio_try_get(folio)) | |
49071d43 KS |
3269 | continue; |
3270 | ||
630e7c5e | 3271 | if (unlikely(page_folio(page) != folio)) |
49071d43 KS |
3272 | goto next; |
3273 | ||
630e7c5e | 3274 | if (zone != folio_zone(folio)) |
49071d43 KS |
3275 | goto next; |
3276 | ||
630e7c5e KW |
3277 | if (!folio_test_large(folio) |
3278 | || folio_test_hugetlb(folio) | |
3279 | || !folio_test_lru(folio)) | |
49071d43 KS |
3280 | goto next; |
3281 | ||
3282 | total++; | |
630e7c5e KW |
3283 | folio_lock(folio); |
3284 | nr_pages = folio_nr_pages(folio); | |
3285 | if (!split_folio(folio)) | |
49071d43 | 3286 | split++; |
a17206da | 3287 | pfn += nr_pages - 1; |
630e7c5e | 3288 | folio_unlock(folio); |
49071d43 | 3289 | next: |
630e7c5e | 3290 | folio_put(folio); |
fa6c0231 | 3291 | cond_resched(); |
49071d43 KS |
3292 | } |
3293 | } | |
3294 | ||
fa6c0231 ZY |
3295 | pr_debug("%lu of %lu THP split\n", split, total); |
3296 | } | |
49071d43 | 3297 | |
fa6c0231 ZY |
3298 | static inline bool vma_not_suitable_for_thp_split(struct vm_area_struct *vma) |
3299 | { | |
3300 | return vma_is_special_huge(vma) || (vma->vm_flags & VM_IO) || | |
3301 | is_vm_hugetlb_page(vma); | |
3302 | } | |
3303 | ||
3304 | static int split_huge_pages_pid(int pid, unsigned long vaddr_start, | |
3305 | unsigned long vaddr_end) | |
3306 | { | |
3307 | int ret = 0; | |
3308 | struct task_struct *task; | |
3309 | struct mm_struct *mm; | |
3310 | unsigned long total = 0, split = 0; | |
3311 | unsigned long addr; | |
3312 | ||
3313 | vaddr_start &= PAGE_MASK; | |
3314 | vaddr_end &= PAGE_MASK; | |
3315 | ||
3316 | /* Find the task_struct from pid */ | |
3317 | rcu_read_lock(); | |
3318 | task = find_task_by_vpid(pid); | |
3319 | if (!task) { | |
3320 | rcu_read_unlock(); | |
3321 | ret = -ESRCH; | |
3322 | goto out; | |
3323 | } | |
3324 | get_task_struct(task); | |
3325 | rcu_read_unlock(); | |
3326 | ||
3327 | /* Find the mm_struct */ | |
3328 | mm = get_task_mm(task); | |
3329 | put_task_struct(task); | |
3330 | ||
3331 | if (!mm) { | |
3332 | ret = -EINVAL; | |
3333 | goto out; | |
3334 | } | |
3335 | ||
3336 | pr_debug("Split huge pages in pid: %d, vaddr: [0x%lx - 0x%lx]\n", | |
3337 | pid, vaddr_start, vaddr_end); | |
3338 | ||
3339 | mmap_read_lock(mm); | |
3340 | /* | |
3341 | * always increase addr by PAGE_SIZE, since we could have a PTE page | |
3342 | * table filled with PTE-mapped THPs, each of which is distinct. | |
3343 | */ | |
3344 | for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) { | |
74ba2b38 | 3345 | struct vm_area_struct *vma = vma_lookup(mm, addr); |
fa6c0231 | 3346 | struct page *page; |
a644b0ab | 3347 | struct folio *folio; |
fa6c0231 | 3348 | |
74ba2b38 | 3349 | if (!vma) |
fa6c0231 ZY |
3350 | break; |
3351 | ||
3352 | /* skip special VMA and hugetlb VMA */ | |
3353 | if (vma_not_suitable_for_thp_split(vma)) { | |
3354 | addr = vma->vm_end; | |
3355 | continue; | |
3356 | } | |
3357 | ||
3358 | /* FOLL_DUMP to ignore special (like zero) pages */ | |
87d2762e | 3359 | page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP); |
fa6c0231 | 3360 | |
f7091ed6 | 3361 | if (IS_ERR_OR_NULL(page)) |
fa6c0231 ZY |
3362 | continue; |
3363 | ||
a644b0ab MWO |
3364 | folio = page_folio(page); |
3365 | if (!is_transparent_hugepage(folio)) | |
fa6c0231 ZY |
3366 | goto next; |
3367 | ||
3368 | total++; | |
a644b0ab | 3369 | if (!can_split_folio(folio, NULL)) |
fa6c0231 ZY |
3370 | goto next; |
3371 | ||
a644b0ab | 3372 | if (!folio_trylock(folio)) |
fa6c0231 ZY |
3373 | goto next; |
3374 | ||
a644b0ab | 3375 | if (!split_folio(folio)) |
fa6c0231 ZY |
3376 | split++; |
3377 | ||
a644b0ab | 3378 | folio_unlock(folio); |
fa6c0231 | 3379 | next: |
a644b0ab | 3380 | folio_put(folio); |
fa6c0231 ZY |
3381 | cond_resched(); |
3382 | } | |
3383 | mmap_read_unlock(mm); | |
3384 | mmput(mm); | |
3385 | ||
3386 | pr_debug("%lu of %lu THP split\n", split, total); | |
3387 | ||
3388 | out: | |
3389 | return ret; | |
49071d43 | 3390 | } |
fa6c0231 | 3391 | |
fbe37501 ZY |
3392 | static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, |
3393 | pgoff_t off_end) | |
3394 | { | |
3395 | struct filename *file; | |
3396 | struct file *candidate; | |
3397 | struct address_space *mapping; | |
3398 | int ret = -EINVAL; | |
3399 | pgoff_t index; | |
3400 | int nr_pages = 1; | |
3401 | unsigned long total = 0, split = 0; | |
3402 | ||
3403 | file = getname_kernel(file_path); | |
3404 | if (IS_ERR(file)) | |
3405 | return ret; | |
3406 | ||
3407 | candidate = file_open_name(file, O_RDONLY, 0); | |
3408 | if (IS_ERR(candidate)) | |
3409 | goto out; | |
3410 | ||
3411 | pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx]\n", | |
3412 | file_path, off_start, off_end); | |
3413 | ||
3414 | mapping = candidate->f_mapping; | |
3415 | ||
3416 | for (index = off_start; index < off_end; index += nr_pages) { | |
1fb130b2 | 3417 | struct folio *folio = filemap_get_folio(mapping, index); |
fbe37501 ZY |
3418 | |
3419 | nr_pages = 1; | |
66dabbb6 | 3420 | if (IS_ERR(folio)) |
fbe37501 ZY |
3421 | continue; |
3422 | ||
9ee2c086 | 3423 | if (!folio_test_large(folio)) |
fbe37501 ZY |
3424 | goto next; |
3425 | ||
3426 | total++; | |
9ee2c086 | 3427 | nr_pages = folio_nr_pages(folio); |
fbe37501 | 3428 | |
9ee2c086 | 3429 | if (!folio_trylock(folio)) |
fbe37501 ZY |
3430 | goto next; |
3431 | ||
9ee2c086 | 3432 | if (!split_folio(folio)) |
fbe37501 ZY |
3433 | split++; |
3434 | ||
9ee2c086 | 3435 | folio_unlock(folio); |
fbe37501 | 3436 | next: |
9ee2c086 | 3437 | folio_put(folio); |
fbe37501 ZY |
3438 | cond_resched(); |
3439 | } | |
3440 | ||
3441 | filp_close(candidate, NULL); | |
3442 | ret = 0; | |
3443 | ||
3444 | pr_debug("%lu of %lu file-backed THP split\n", split, total); | |
3445 | out: | |
3446 | putname(file); | |
3447 | return ret; | |
3448 | } | |
3449 | ||
fa6c0231 ZY |
3450 | #define MAX_INPUT_BUF_SZ 255 |
3451 | ||
3452 | static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, | |
3453 | size_t count, loff_t *ppops) | |
3454 | { | |
3455 | static DEFINE_MUTEX(split_debug_mutex); | |
3456 | ssize_t ret; | |
fbe37501 ZY |
3457 | /* hold pid, start_vaddr, end_vaddr or file_path, off_start, off_end */ |
3458 | char input_buf[MAX_INPUT_BUF_SZ]; | |
fa6c0231 ZY |
3459 | int pid; |
3460 | unsigned long vaddr_start, vaddr_end; | |
3461 | ||
3462 | ret = mutex_lock_interruptible(&split_debug_mutex); | |
3463 | if (ret) | |
3464 | return ret; | |
3465 | ||
3466 | ret = -EFAULT; | |
3467 | ||
3468 | memset(input_buf, 0, MAX_INPUT_BUF_SZ); | |
3469 | if (copy_from_user(input_buf, buf, min_t(size_t, count, MAX_INPUT_BUF_SZ))) | |
3470 | goto out; | |
3471 | ||
3472 | input_buf[MAX_INPUT_BUF_SZ - 1] = '\0'; | |
fbe37501 ZY |
3473 | |
3474 | if (input_buf[0] == '/') { | |
3475 | char *tok; | |
3476 | char *buf = input_buf; | |
3477 | char file_path[MAX_INPUT_BUF_SZ]; | |
3478 | pgoff_t off_start = 0, off_end = 0; | |
3479 | size_t input_len = strlen(input_buf); | |
3480 | ||
3481 | tok = strsep(&buf, ","); | |
3482 | if (tok) { | |
1212e00c | 3483 | strcpy(file_path, tok); |
fbe37501 ZY |
3484 | } else { |
3485 | ret = -EINVAL; | |
3486 | goto out; | |
3487 | } | |
3488 | ||
3489 | ret = sscanf(buf, "0x%lx,0x%lx", &off_start, &off_end); | |
3490 | if (ret != 2) { | |
3491 | ret = -EINVAL; | |
3492 | goto out; | |
3493 | } | |
3494 | ret = split_huge_pages_in_file(file_path, off_start, off_end); | |
3495 | if (!ret) | |
3496 | ret = input_len; | |
3497 | ||
3498 | goto out; | |
3499 | } | |
3500 | ||
fa6c0231 ZY |
3501 | ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); |
3502 | if (ret == 1 && pid == 1) { | |
3503 | split_huge_pages_all(); | |
3504 | ret = strlen(input_buf); | |
3505 | goto out; | |
3506 | } else if (ret != 3) { | |
3507 | ret = -EINVAL; | |
3508 | goto out; | |
3509 | } | |
3510 | ||
3511 | ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end); | |
3512 | if (!ret) | |
3513 | ret = strlen(input_buf); | |
3514 | out: | |
3515 | mutex_unlock(&split_debug_mutex); | |
3516 | return ret; | |
3517 | ||
3518 | } | |
3519 | ||
3520 | static const struct file_operations split_huge_pages_fops = { | |
3521 | .owner = THIS_MODULE, | |
3522 | .write = split_huge_pages_write, | |
3523 | .llseek = no_llseek, | |
3524 | }; | |
49071d43 KS |
3525 | |
3526 | static int __init split_huge_pages_debugfs(void) | |
3527 | { | |
d9f7979c GKH |
3528 | debugfs_create_file("split_huge_pages", 0200, NULL, NULL, |
3529 | &split_huge_pages_fops); | |
49071d43 KS |
3530 | return 0; |
3531 | } | |
3532 | late_initcall(split_huge_pages_debugfs); | |
3533 | #endif | |
616b8371 ZY |
3534 | |
3535 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
7f5abe60 | 3536 | int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, |
616b8371 ZY |
3537 | struct page *page) |
3538 | { | |
3539 | struct vm_area_struct *vma = pvmw->vma; | |
3540 | struct mm_struct *mm = vma->vm_mm; | |
3541 | unsigned long address = pvmw->address; | |
6c287605 | 3542 | bool anon_exclusive; |
616b8371 ZY |
3543 | pmd_t pmdval; |
3544 | swp_entry_t entry; | |
ab6e3d09 | 3545 | pmd_t pmdswp; |
616b8371 ZY |
3546 | |
3547 | if (!(pvmw->pmd && !pvmw->pte)) | |
7f5abe60 | 3548 | return 0; |
616b8371 | 3549 | |
616b8371 | 3550 | flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); |
8a8683ad | 3551 | pmdval = pmdp_invalidate(vma, address, pvmw->pmd); |
6c287605 | 3552 | |
088b8aa5 | 3553 | /* See page_try_share_anon_rmap(): invalidate PMD first. */ |
6c287605 DH |
3554 | anon_exclusive = PageAnon(page) && PageAnonExclusive(page); |
3555 | if (anon_exclusive && page_try_share_anon_rmap(page)) { | |
3556 | set_pmd_at(mm, address, pvmw->pmd, pmdval); | |
7f5abe60 | 3557 | return -EBUSY; |
6c287605 DH |
3558 | } |
3559 | ||
616b8371 ZY |
3560 | if (pmd_dirty(pmdval)) |
3561 | set_page_dirty(page); | |
4dd845b5 AP |
3562 | if (pmd_write(pmdval)) |
3563 | entry = make_writable_migration_entry(page_to_pfn(page)); | |
6c287605 DH |
3564 | else if (anon_exclusive) |
3565 | entry = make_readable_exclusive_migration_entry(page_to_pfn(page)); | |
4dd845b5 AP |
3566 | else |
3567 | entry = make_readable_migration_entry(page_to_pfn(page)); | |
2e346877 PX |
3568 | if (pmd_young(pmdval)) |
3569 | entry = make_migration_entry_young(entry); | |
3570 | if (pmd_dirty(pmdval)) | |
3571 | entry = make_migration_entry_dirty(entry); | |
ab6e3d09 NH |
3572 | pmdswp = swp_entry_to_pmd(entry); |
3573 | if (pmd_soft_dirty(pmdval)) | |
3574 | pmdswp = pmd_swp_mksoft_dirty(pmdswp); | |
24bf08c4 DH |
3575 | if (pmd_uffd_wp(pmdval)) |
3576 | pmdswp = pmd_swp_mkuffd_wp(pmdswp); | |
ab6e3d09 | 3577 | set_pmd_at(mm, address, pvmw->pmd, pmdswp); |
cea86fe2 | 3578 | page_remove_rmap(page, vma, true); |
616b8371 | 3579 | put_page(page); |
283fd6fe | 3580 | trace_set_migration_pmd(address, pmd_val(pmdswp)); |
7f5abe60 DH |
3581 | |
3582 | return 0; | |
616b8371 ZY |
3583 | } |
3584 | ||
3585 | void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) | |
3586 | { | |
14d85a6e | 3587 | struct folio *folio = page_folio(new); |
616b8371 ZY |
3588 | struct vm_area_struct *vma = pvmw->vma; |
3589 | struct mm_struct *mm = vma->vm_mm; | |
3590 | unsigned long address = pvmw->address; | |
4fba8f2a | 3591 | unsigned long haddr = address & HPAGE_PMD_MASK; |
616b8371 ZY |
3592 | pmd_t pmde; |
3593 | swp_entry_t entry; | |
3594 | ||
3595 | if (!(pvmw->pmd && !pvmw->pte)) | |
3596 | return; | |
3597 | ||
3598 | entry = pmd_to_swp_entry(*pvmw->pmd); | |
14d85a6e | 3599 | folio_get(folio); |
2e346877 | 3600 | pmde = mk_huge_pmd(new, READ_ONCE(vma->vm_page_prot)); |
ab6e3d09 NH |
3601 | if (pmd_swp_soft_dirty(*pvmw->pmd)) |
3602 | pmde = pmd_mksoft_dirty(pmde); | |
3c811f78 | 3603 | if (is_writable_migration_entry(entry)) |
161e393c | 3604 | pmde = pmd_mkwrite(pmde, vma); |
8f34f1ea | 3605 | if (pmd_swp_uffd_wp(*pvmw->pmd)) |
f1eb1bac | 3606 | pmde = pmd_mkuffd_wp(pmde); |
2e346877 PX |
3607 | if (!is_migration_entry_young(entry)) |
3608 | pmde = pmd_mkold(pmde); | |
3609 | /* NOTE: this may contain setting soft-dirty on some archs */ | |
14d85a6e | 3610 | if (folio_test_dirty(folio) && is_migration_entry_dirty(entry)) |
2e346877 | 3611 | pmde = pmd_mkdirty(pmde); |
616b8371 | 3612 | |
14d85a6e | 3613 | if (folio_test_anon(folio)) { |
395db7b1 | 3614 | rmap_t rmap_flags = RMAP_NONE; |
6c287605 DH |
3615 | |
3616 | if (!is_readable_migration_entry(entry)) | |
3617 | rmap_flags |= RMAP_EXCLUSIVE; | |
3618 | ||
395db7b1 | 3619 | folio_add_anon_rmap_pmd(folio, new, vma, haddr, rmap_flags); |
6c287605 | 3620 | } else { |
14d85a6e | 3621 | folio_add_file_rmap_pmd(folio, new, vma); |
6c287605 | 3622 | } |
14d85a6e | 3623 | VM_BUG_ON(pmd_write(pmde) && folio_test_anon(folio) && !PageAnonExclusive(new)); |
4fba8f2a | 3624 | set_pmd_at(mm, haddr, pvmw->pmd, pmde); |
5cbcf225 MS |
3625 | |
3626 | /* No need to invalidate - it was non-present before */ | |
616b8371 | 3627 | update_mmu_cache_pmd(vma, address, pvmw->pmd); |
283fd6fe | 3628 | trace_remove_migration_pmd(address, pmd_val(pmde)); |
616b8371 ZY |
3629 | } |
3630 | #endif |