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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
a2c16d6c HD |
2 | #ifndef _LINUX_SWAPOPS_H |
3 | #define _LINUX_SWAPOPS_H | |
4 | ||
5 | #include <linux/radix-tree.h> | |
187f1882 | 6 | #include <linux/bug.h> |
2b740303 | 7 | #include <linux/mm_types.h> |
a2c16d6c | 8 | |
9b98fa22 CH |
9 | #ifdef CONFIG_MMU |
10 | ||
1da177e4 LT |
11 | /* |
12 | * swapcache pages are stored in the swapper_space radix tree. We want to | |
13 | * get good packing density in that tree, so the index should be dense in | |
14 | * the low-order bits. | |
15 | * | |
9b15b817 | 16 | * We arrange the `type' and `offset' fields so that `type' is at the seven |
e83a9596 | 17 | * high-order bits of the swp_entry_t and `offset' is right-aligned in the |
9b15b817 HD |
18 | * remaining bits. Although `type' itself needs only five bits, we allow for |
19 | * shmem/tmpfs to shift it all up a further two bits: see swp_to_radix_entry(). | |
1da177e4 LT |
20 | * |
21 | * swp_entry_t's are *never* stored anywhere in their arch-dependent format. | |
22 | */ | |
3159f943 MW |
23 | #define SWP_TYPE_SHIFT (BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT) |
24 | #define SWP_OFFSET_MASK ((1UL << SWP_TYPE_SHIFT) - 1) | |
1da177e4 | 25 | |
099dd687 PX |
26 | /* Clear all flags but only keep swp_entry_t related information */ |
27 | static inline pte_t pte_swp_clear_flags(pte_t pte) | |
28 | { | |
1493a191 DH |
29 | if (pte_swp_exclusive(pte)) |
30 | pte = pte_swp_clear_exclusive(pte); | |
099dd687 PX |
31 | if (pte_swp_soft_dirty(pte)) |
32 | pte = pte_swp_clear_soft_dirty(pte); | |
33 | if (pte_swp_uffd_wp(pte)) | |
34 | pte = pte_swp_clear_uffd_wp(pte); | |
35 | return pte; | |
36 | } | |
37 | ||
1da177e4 LT |
38 | /* |
39 | * Store a type+offset into a swp_entry_t in an arch-independent format | |
40 | */ | |
41 | static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset) | |
42 | { | |
43 | swp_entry_t ret; | |
44 | ||
3159f943 | 45 | ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK); |
1da177e4 LT |
46 | return ret; |
47 | } | |
48 | ||
49 | /* | |
50 | * Extract the `type' field from a swp_entry_t. The swp_entry_t is in | |
51 | * arch-independent format | |
52 | */ | |
53 | static inline unsigned swp_type(swp_entry_t entry) | |
54 | { | |
3159f943 | 55 | return (entry.val >> SWP_TYPE_SHIFT); |
1da177e4 LT |
56 | } |
57 | ||
58 | /* | |
59 | * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in | |
60 | * arch-independent format | |
61 | */ | |
62 | static inline pgoff_t swp_offset(swp_entry_t entry) | |
63 | { | |
3159f943 | 64 | return entry.val & SWP_OFFSET_MASK; |
1da177e4 LT |
65 | } |
66 | ||
698dd4ba MM |
67 | /* check whether a pte points to a swap entry */ |
68 | static inline int is_swap_pte(pte_t pte) | |
69 | { | |
21d9ee3e | 70 | return !pte_none(pte) && !pte_present(pte); |
698dd4ba MM |
71 | } |
72 | ||
1da177e4 LT |
73 | /* |
74 | * Convert the arch-dependent pte representation of a swp_entry_t into an | |
75 | * arch-independent swp_entry_t. | |
76 | */ | |
77 | static inline swp_entry_t pte_to_swp_entry(pte_t pte) | |
78 | { | |
79 | swp_entry_t arch_entry; | |
80 | ||
099dd687 | 81 | pte = pte_swp_clear_flags(pte); |
1da177e4 LT |
82 | arch_entry = __pte_to_swp_entry(pte); |
83 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
84 | } | |
85 | ||
86 | /* | |
87 | * Convert the arch-independent representation of a swp_entry_t into the | |
88 | * arch-dependent pte representation. | |
89 | */ | |
90 | static inline pte_t swp_entry_to_pte(swp_entry_t entry) | |
91 | { | |
92 | swp_entry_t arch_entry; | |
93 | ||
94 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
1da177e4 LT |
95 | return __swp_entry_to_pte(arch_entry); |
96 | } | |
0697212a | 97 | |
a2c16d6c HD |
98 | static inline swp_entry_t radix_to_swp_entry(void *arg) |
99 | { | |
100 | swp_entry_t entry; | |
101 | ||
3159f943 | 102 | entry.val = xa_to_value(arg); |
a2c16d6c HD |
103 | return entry; |
104 | } | |
105 | ||
106 | static inline void *swp_to_radix_entry(swp_entry_t entry) | |
107 | { | |
3159f943 | 108 | return xa_mk_value(entry.val); |
a2c16d6c HD |
109 | } |
110 | ||
5042db43 | 111 | #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) |
4dd845b5 | 112 | static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) |
5042db43 | 113 | { |
4dd845b5 | 114 | return swp_entry(SWP_DEVICE_READ, offset); |
5042db43 JG |
115 | } |
116 | ||
4dd845b5 | 117 | static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset) |
5042db43 | 118 | { |
4dd845b5 | 119 | return swp_entry(SWP_DEVICE_WRITE, offset); |
5042db43 JG |
120 | } |
121 | ||
4dd845b5 | 122 | static inline bool is_device_private_entry(swp_entry_t entry) |
5042db43 | 123 | { |
4dd845b5 AP |
124 | int type = swp_type(entry); |
125 | return type == SWP_DEVICE_READ || type == SWP_DEVICE_WRITE; | |
5042db43 JG |
126 | } |
127 | ||
4dd845b5 | 128 | static inline bool is_writable_device_private_entry(swp_entry_t entry) |
5042db43 JG |
129 | { |
130 | return unlikely(swp_type(entry) == SWP_DEVICE_WRITE); | |
131 | } | |
b756a3b5 AP |
132 | |
133 | static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset) | |
134 | { | |
135 | return swp_entry(SWP_DEVICE_EXCLUSIVE_READ, offset); | |
136 | } | |
137 | ||
138 | static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset) | |
139 | { | |
140 | return swp_entry(SWP_DEVICE_EXCLUSIVE_WRITE, offset); | |
141 | } | |
142 | ||
143 | static inline bool is_device_exclusive_entry(swp_entry_t entry) | |
144 | { | |
145 | return swp_type(entry) == SWP_DEVICE_EXCLUSIVE_READ || | |
146 | swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE; | |
147 | } | |
148 | ||
149 | static inline bool is_writable_device_exclusive_entry(swp_entry_t entry) | |
150 | { | |
151 | return unlikely(swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE); | |
152 | } | |
5042db43 | 153 | #else /* CONFIG_DEVICE_PRIVATE */ |
4dd845b5 | 154 | static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) |
5042db43 JG |
155 | { |
156 | return swp_entry(0, 0); | |
157 | } | |
158 | ||
4dd845b5 | 159 | static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset) |
5042db43 | 160 | { |
4dd845b5 | 161 | return swp_entry(0, 0); |
5042db43 JG |
162 | } |
163 | ||
164 | static inline bool is_device_private_entry(swp_entry_t entry) | |
165 | { | |
166 | return false; | |
167 | } | |
168 | ||
4dd845b5 | 169 | static inline bool is_writable_device_private_entry(swp_entry_t entry) |
5042db43 JG |
170 | { |
171 | return false; | |
172 | } | |
b756a3b5 AP |
173 | |
174 | static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset) | |
175 | { | |
176 | return swp_entry(0, 0); | |
177 | } | |
178 | ||
179 | static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset) | |
180 | { | |
181 | return swp_entry(0, 0); | |
182 | } | |
183 | ||
184 | static inline bool is_device_exclusive_entry(swp_entry_t entry) | |
185 | { | |
186 | return false; | |
187 | } | |
188 | ||
189 | static inline bool is_writable_device_exclusive_entry(swp_entry_t entry) | |
190 | { | |
191 | return false; | |
192 | } | |
5042db43 JG |
193 | #endif /* CONFIG_DEVICE_PRIVATE */ |
194 | ||
0697212a | 195 | #ifdef CONFIG_MIGRATION |
0697212a CL |
196 | static inline int is_migration_entry(swp_entry_t entry) |
197 | { | |
198 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ || | |
6c287605 | 199 | swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE || |
0697212a CL |
200 | swp_type(entry) == SWP_MIGRATION_WRITE); |
201 | } | |
202 | ||
4dd845b5 | 203 | static inline int is_writable_migration_entry(swp_entry_t entry) |
0697212a CL |
204 | { |
205 | return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE); | |
206 | } | |
207 | ||
6c287605 DH |
208 | static inline int is_readable_migration_entry(swp_entry_t entry) |
209 | { | |
210 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ); | |
211 | } | |
212 | ||
213 | static inline int is_readable_exclusive_migration_entry(swp_entry_t entry) | |
214 | { | |
215 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE); | |
216 | } | |
217 | ||
4dd845b5 | 218 | static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) |
0697212a | 219 | { |
4dd845b5 AP |
220 | return swp_entry(SWP_MIGRATION_READ, offset); |
221 | } | |
222 | ||
6c287605 DH |
223 | static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset) |
224 | { | |
225 | return swp_entry(SWP_MIGRATION_READ_EXCLUSIVE, offset); | |
226 | } | |
227 | ||
4dd845b5 AP |
228 | static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) |
229 | { | |
230 | return swp_entry(SWP_MIGRATION_WRITE, offset); | |
0697212a CL |
231 | } |
232 | ||
e66f17ff NH |
233 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
234 | spinlock_t *ptl); | |
0697212a CL |
235 | extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
236 | unsigned long address); | |
cb900f41 KS |
237 | extern void migration_entry_wait_huge(struct vm_area_struct *vma, |
238 | struct mm_struct *mm, pte_t *pte); | |
0697212a | 239 | #else |
4dd845b5 AP |
240 | static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) |
241 | { | |
242 | return swp_entry(0, 0); | |
243 | } | |
244 | ||
6c287605 DH |
245 | static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset) |
246 | { | |
247 | return swp_entry(0, 0); | |
248 | } | |
249 | ||
4dd845b5 AP |
250 | static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) |
251 | { | |
252 | return swp_entry(0, 0); | |
253 | } | |
0697212a | 254 | |
5ec553a9 AM |
255 | static inline int is_migration_entry(swp_entry_t swp) |
256 | { | |
257 | return 0; | |
258 | } | |
0d665e7b | 259 | |
e66f17ff NH |
260 | static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
261 | spinlock_t *ptl) { } | |
0697212a CL |
262 | static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
263 | unsigned long address) { } | |
cb900f41 KS |
264 | static inline void migration_entry_wait_huge(struct vm_area_struct *vma, |
265 | struct mm_struct *mm, pte_t *pte) { } | |
4dd845b5 | 266 | static inline int is_writable_migration_entry(swp_entry_t entry) |
0697212a CL |
267 | { |
268 | return 0; | |
269 | } | |
6c287605 DH |
270 | static inline int is_readable_migration_entry(swp_entry_t entry) |
271 | { | |
272 | return 0; | |
273 | } | |
0697212a CL |
274 | |
275 | #endif | |
276 | ||
679d1033 PX |
277 | typedef unsigned long pte_marker; |
278 | ||
1db9dbc2 PX |
279 | #define PTE_MARKER_UFFD_WP BIT(0) |
280 | #define PTE_MARKER_MASK (PTE_MARKER_UFFD_WP) | |
679d1033 PX |
281 | |
282 | #ifdef CONFIG_PTE_MARKER | |
283 | ||
284 | static inline swp_entry_t make_pte_marker_entry(pte_marker marker) | |
285 | { | |
286 | return swp_entry(SWP_PTE_MARKER, marker); | |
287 | } | |
288 | ||
289 | static inline bool is_pte_marker_entry(swp_entry_t entry) | |
290 | { | |
291 | return swp_type(entry) == SWP_PTE_MARKER; | |
292 | } | |
293 | ||
294 | static inline pte_marker pte_marker_get(swp_entry_t entry) | |
295 | { | |
296 | return swp_offset(entry) & PTE_MARKER_MASK; | |
297 | } | |
298 | ||
299 | static inline bool is_pte_marker(pte_t pte) | |
300 | { | |
301 | return is_swap_pte(pte) && is_pte_marker_entry(pte_to_swp_entry(pte)); | |
302 | } | |
303 | ||
304 | #else /* CONFIG_PTE_MARKER */ | |
305 | ||
306 | static inline swp_entry_t make_pte_marker_entry(pte_marker marker) | |
307 | { | |
308 | /* This should never be called if !CONFIG_PTE_MARKER */ | |
309 | WARN_ON_ONCE(1); | |
310 | return swp_entry(0, 0); | |
311 | } | |
312 | ||
313 | static inline bool is_pte_marker_entry(swp_entry_t entry) | |
314 | { | |
315 | return false; | |
316 | } | |
317 | ||
318 | static inline pte_marker pte_marker_get(swp_entry_t entry) | |
319 | { | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static inline bool is_pte_marker(pte_t pte) | |
324 | { | |
325 | return false; | |
326 | } | |
327 | ||
328 | #endif /* CONFIG_PTE_MARKER */ | |
329 | ||
330 | static inline pte_t make_pte_marker(pte_marker marker) | |
331 | { | |
332 | return swp_entry_to_pte(make_pte_marker_entry(marker)); | |
333 | } | |
334 | ||
335 | /* | |
336 | * This is a special version to check pte_none() just to cover the case when | |
337 | * the pte is a pte marker. It existed because in many cases the pte marker | |
338 | * should be seen as a none pte; it's just that we have stored some information | |
339 | * onto the none pte so it becomes not-none any more. | |
340 | * | |
341 | * It should be used when the pte is file-backed, ram-based and backing | |
342 | * userspace pages, like shmem. It is not needed upon pgtables that do not | |
343 | * support pte markers at all. For example, it's not needed on anonymous | |
344 | * memory, kernel-only memory (including when the system is during-boot), | |
345 | * non-ram based generic file-system. It's fine to be used even there, but the | |
346 | * extra pte marker check will be pure overhead. | |
347 | * | |
348 | * For systems configured with !CONFIG_PTE_MARKER this will be automatically | |
349 | * optimized to pte_none(). | |
350 | */ | |
351 | static inline int pte_none_mostly(pte_t pte) | |
352 | { | |
353 | return pte_none(pte) || is_pte_marker(pte); | |
354 | } | |
355 | ||
af5cdaf8 AP |
356 | static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry) |
357 | { | |
358 | struct page *p = pfn_to_page(swp_offset(entry)); | |
359 | ||
360 | /* | |
361 | * Any use of migration entries may only occur while the | |
362 | * corresponding page is locked | |
363 | */ | |
364 | BUG_ON(is_migration_entry(entry) && !PageLocked(p)); | |
365 | ||
366 | return p; | |
367 | } | |
368 | ||
369 | /* | |
370 | * A pfn swap entry is a special type of swap entry that always has a pfn stored | |
371 | * in the swap offset. They are used to represent unaddressable device memory | |
372 | * and to restrict access to a page undergoing migration. | |
373 | */ | |
374 | static inline bool is_pfn_swap_entry(swp_entry_t entry) | |
375 | { | |
b756a3b5 AP |
376 | return is_migration_entry(entry) || is_device_private_entry(entry) || |
377 | is_device_exclusive_entry(entry); | |
af5cdaf8 AP |
378 | } |
379 | ||
616b8371 ZY |
380 | struct page_vma_mapped_walk; |
381 | ||
382 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
7f5abe60 | 383 | extern int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, |
616b8371 ZY |
384 | struct page *page); |
385 | ||
386 | extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
387 | struct page *new); | |
388 | ||
389 | extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); | |
390 | ||
391 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
392 | { | |
393 | swp_entry_t arch_entry; | |
394 | ||
ab6e3d09 NH |
395 | if (pmd_swp_soft_dirty(pmd)) |
396 | pmd = pmd_swp_clear_soft_dirty(pmd); | |
8f34f1ea PX |
397 | if (pmd_swp_uffd_wp(pmd)) |
398 | pmd = pmd_swp_clear_uffd_wp(pmd); | |
616b8371 ZY |
399 | arch_entry = __pmd_to_swp_entry(pmd); |
400 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
401 | } | |
402 | ||
403 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
404 | { | |
405 | swp_entry_t arch_entry; | |
406 | ||
407 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
408 | return __swp_entry_to_pmd(arch_entry); | |
409 | } | |
410 | ||
411 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
412 | { | |
b304c6f0 | 413 | return is_swap_pmd(pmd) && is_migration_entry(pmd_to_swp_entry(pmd)); |
616b8371 ZY |
414 | } |
415 | #else | |
7f5abe60 | 416 | static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, |
616b8371 ZY |
417 | struct page *page) |
418 | { | |
419 | BUILD_BUG(); | |
420 | } | |
421 | ||
422 | static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
423 | struct page *new) | |
424 | { | |
425 | BUILD_BUG(); | |
426 | } | |
427 | ||
428 | static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { } | |
429 | ||
430 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
431 | { | |
432 | return swp_entry(0, 0); | |
433 | } | |
434 | ||
435 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
436 | { | |
437 | return __pmd(0); | |
438 | } | |
439 | ||
440 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
441 | { | |
442 | return 0; | |
443 | } | |
444 | #endif | |
445 | ||
a7420aa5 | 446 | #ifdef CONFIG_MEMORY_FAILURE |
8e30456b NH |
447 | |
448 | extern atomic_long_t num_poisoned_pages __read_mostly; | |
449 | ||
a7420aa5 AK |
450 | /* |
451 | * Support for hardware poisoned pages | |
452 | */ | |
453 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
454 | { | |
455 | BUG_ON(!PageLocked(page)); | |
456 | return swp_entry(SWP_HWPOISON, page_to_pfn(page)); | |
457 | } | |
458 | ||
459 | static inline int is_hwpoison_entry(swp_entry_t entry) | |
460 | { | |
461 | return swp_type(entry) == SWP_HWPOISON; | |
462 | } | |
8e30456b | 463 | |
a3f5d80e NH |
464 | static inline unsigned long hwpoison_entry_to_pfn(swp_entry_t entry) |
465 | { | |
466 | return swp_offset(entry); | |
467 | } | |
468 | ||
8e30456b NH |
469 | static inline void num_poisoned_pages_inc(void) |
470 | { | |
471 | atomic_long_inc(&num_poisoned_pages); | |
472 | } | |
473 | ||
474 | static inline void num_poisoned_pages_dec(void) | |
475 | { | |
476 | atomic_long_dec(&num_poisoned_pages); | |
477 | } | |
478 | ||
a7420aa5 AK |
479 | #else |
480 | ||
481 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
482 | { | |
483 | return swp_entry(0, 0); | |
484 | } | |
485 | ||
486 | static inline int is_hwpoison_entry(swp_entry_t swp) | |
487 | { | |
488 | return 0; | |
489 | } | |
da1b13cc | 490 | |
da1b13cc WL |
491 | static inline void num_poisoned_pages_inc(void) |
492 | { | |
493 | } | |
a7420aa5 AK |
494 | #endif |
495 | ||
a7420aa5 AK |
496 | static inline int non_swap_entry(swp_entry_t entry) |
497 | { | |
498 | return swp_type(entry) >= MAX_SWAPFILES; | |
499 | } | |
a2c16d6c | 500 | |
9b98fa22 | 501 | #endif /* CONFIG_MMU */ |
a2c16d6c | 502 | #endif /* _LINUX_SWAPOPS_H */ |