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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 | { | |
29 | if (pte_swp_soft_dirty(pte)) | |
30 | pte = pte_swp_clear_soft_dirty(pte); | |
31 | if (pte_swp_uffd_wp(pte)) | |
32 | pte = pte_swp_clear_uffd_wp(pte); | |
33 | return pte; | |
34 | } | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * Store a type+offset into a swp_entry_t in an arch-independent format | |
38 | */ | |
39 | static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset) | |
40 | { | |
41 | swp_entry_t ret; | |
42 | ||
3159f943 | 43 | ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK); |
1da177e4 LT |
44 | return ret; |
45 | } | |
46 | ||
47 | /* | |
48 | * Extract the `type' field from a swp_entry_t. The swp_entry_t is in | |
49 | * arch-independent format | |
50 | */ | |
51 | static inline unsigned swp_type(swp_entry_t entry) | |
52 | { | |
3159f943 | 53 | return (entry.val >> SWP_TYPE_SHIFT); |
1da177e4 LT |
54 | } |
55 | ||
56 | /* | |
57 | * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in | |
58 | * arch-independent format | |
59 | */ | |
60 | static inline pgoff_t swp_offset(swp_entry_t entry) | |
61 | { | |
3159f943 | 62 | return entry.val & SWP_OFFSET_MASK; |
1da177e4 LT |
63 | } |
64 | ||
698dd4ba MM |
65 | /* check whether a pte points to a swap entry */ |
66 | static inline int is_swap_pte(pte_t pte) | |
67 | { | |
21d9ee3e | 68 | return !pte_none(pte) && !pte_present(pte); |
698dd4ba MM |
69 | } |
70 | ||
1da177e4 LT |
71 | /* |
72 | * Convert the arch-dependent pte representation of a swp_entry_t into an | |
73 | * arch-independent swp_entry_t. | |
74 | */ | |
75 | static inline swp_entry_t pte_to_swp_entry(pte_t pte) | |
76 | { | |
77 | swp_entry_t arch_entry; | |
78 | ||
099dd687 | 79 | pte = pte_swp_clear_flags(pte); |
1da177e4 LT |
80 | arch_entry = __pte_to_swp_entry(pte); |
81 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
82 | } | |
83 | ||
84 | /* | |
85 | * Convert the arch-independent representation of a swp_entry_t into the | |
86 | * arch-dependent pte representation. | |
87 | */ | |
88 | static inline pte_t swp_entry_to_pte(swp_entry_t entry) | |
89 | { | |
90 | swp_entry_t arch_entry; | |
91 | ||
92 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
1da177e4 LT |
93 | return __swp_entry_to_pte(arch_entry); |
94 | } | |
0697212a | 95 | |
a2c16d6c HD |
96 | static inline swp_entry_t radix_to_swp_entry(void *arg) |
97 | { | |
98 | swp_entry_t entry; | |
99 | ||
3159f943 | 100 | entry.val = xa_to_value(arg); |
a2c16d6c HD |
101 | return entry; |
102 | } | |
103 | ||
104 | static inline void *swp_to_radix_entry(swp_entry_t entry) | |
105 | { | |
3159f943 | 106 | return xa_mk_value(entry.val); |
a2c16d6c HD |
107 | } |
108 | ||
5042db43 | 109 | #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) |
4dd845b5 | 110 | static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) |
5042db43 | 111 | { |
4dd845b5 | 112 | return swp_entry(SWP_DEVICE_READ, offset); |
5042db43 JG |
113 | } |
114 | ||
4dd845b5 | 115 | static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset) |
5042db43 | 116 | { |
4dd845b5 | 117 | return swp_entry(SWP_DEVICE_WRITE, offset); |
5042db43 JG |
118 | } |
119 | ||
4dd845b5 | 120 | static inline bool is_device_private_entry(swp_entry_t entry) |
5042db43 | 121 | { |
4dd845b5 AP |
122 | int type = swp_type(entry); |
123 | return type == SWP_DEVICE_READ || type == SWP_DEVICE_WRITE; | |
5042db43 JG |
124 | } |
125 | ||
4dd845b5 | 126 | static inline bool is_writable_device_private_entry(swp_entry_t entry) |
5042db43 JG |
127 | { |
128 | return unlikely(swp_type(entry) == SWP_DEVICE_WRITE); | |
129 | } | |
b756a3b5 AP |
130 | |
131 | static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset) | |
132 | { | |
133 | return swp_entry(SWP_DEVICE_EXCLUSIVE_READ, offset); | |
134 | } | |
135 | ||
136 | static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset) | |
137 | { | |
138 | return swp_entry(SWP_DEVICE_EXCLUSIVE_WRITE, offset); | |
139 | } | |
140 | ||
141 | static inline bool is_device_exclusive_entry(swp_entry_t entry) | |
142 | { | |
143 | return swp_type(entry) == SWP_DEVICE_EXCLUSIVE_READ || | |
144 | swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE; | |
145 | } | |
146 | ||
147 | static inline bool is_writable_device_exclusive_entry(swp_entry_t entry) | |
148 | { | |
149 | return unlikely(swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE); | |
150 | } | |
5042db43 | 151 | #else /* CONFIG_DEVICE_PRIVATE */ |
4dd845b5 | 152 | static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) |
5042db43 JG |
153 | { |
154 | return swp_entry(0, 0); | |
155 | } | |
156 | ||
4dd845b5 | 157 | static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset) |
5042db43 | 158 | { |
4dd845b5 | 159 | return swp_entry(0, 0); |
5042db43 JG |
160 | } |
161 | ||
162 | static inline bool is_device_private_entry(swp_entry_t entry) | |
163 | { | |
164 | return false; | |
165 | } | |
166 | ||
4dd845b5 | 167 | static inline bool is_writable_device_private_entry(swp_entry_t entry) |
5042db43 JG |
168 | { |
169 | return false; | |
170 | } | |
b756a3b5 AP |
171 | |
172 | static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset) | |
173 | { | |
174 | return swp_entry(0, 0); | |
175 | } | |
176 | ||
177 | static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset) | |
178 | { | |
179 | return swp_entry(0, 0); | |
180 | } | |
181 | ||
182 | static inline bool is_device_exclusive_entry(swp_entry_t entry) | |
183 | { | |
184 | return false; | |
185 | } | |
186 | ||
187 | static inline bool is_writable_device_exclusive_entry(swp_entry_t entry) | |
188 | { | |
189 | return false; | |
190 | } | |
5042db43 JG |
191 | #endif /* CONFIG_DEVICE_PRIVATE */ |
192 | ||
0697212a | 193 | #ifdef CONFIG_MIGRATION |
0697212a CL |
194 | static inline int is_migration_entry(swp_entry_t entry) |
195 | { | |
196 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ || | |
197 | swp_type(entry) == SWP_MIGRATION_WRITE); | |
198 | } | |
199 | ||
4dd845b5 | 200 | static inline int is_writable_migration_entry(swp_entry_t entry) |
0697212a CL |
201 | { |
202 | return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE); | |
203 | } | |
204 | ||
4dd845b5 | 205 | static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) |
0697212a | 206 | { |
4dd845b5 AP |
207 | return swp_entry(SWP_MIGRATION_READ, offset); |
208 | } | |
209 | ||
210 | static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) | |
211 | { | |
212 | return swp_entry(SWP_MIGRATION_WRITE, offset); | |
0697212a CL |
213 | } |
214 | ||
e66f17ff NH |
215 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
216 | spinlock_t *ptl); | |
0697212a CL |
217 | extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
218 | unsigned long address); | |
cb900f41 KS |
219 | extern void migration_entry_wait_huge(struct vm_area_struct *vma, |
220 | struct mm_struct *mm, pte_t *pte); | |
0697212a | 221 | #else |
4dd845b5 AP |
222 | static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) |
223 | { | |
224 | return swp_entry(0, 0); | |
225 | } | |
226 | ||
227 | static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) | |
228 | { | |
229 | return swp_entry(0, 0); | |
230 | } | |
0697212a | 231 | |
5ec553a9 AM |
232 | static inline int is_migration_entry(swp_entry_t swp) |
233 | { | |
234 | return 0; | |
235 | } | |
0d665e7b | 236 | |
e66f17ff NH |
237 | static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
238 | spinlock_t *ptl) { } | |
0697212a CL |
239 | static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
240 | unsigned long address) { } | |
cb900f41 KS |
241 | static inline void migration_entry_wait_huge(struct vm_area_struct *vma, |
242 | struct mm_struct *mm, pte_t *pte) { } | |
4dd845b5 | 243 | static inline int is_writable_migration_entry(swp_entry_t entry) |
0697212a CL |
244 | { |
245 | return 0; | |
246 | } | |
247 | ||
248 | #endif | |
249 | ||
af5cdaf8 AP |
250 | static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry) |
251 | { | |
252 | struct page *p = pfn_to_page(swp_offset(entry)); | |
253 | ||
254 | /* | |
255 | * Any use of migration entries may only occur while the | |
256 | * corresponding page is locked | |
257 | */ | |
258 | BUG_ON(is_migration_entry(entry) && !PageLocked(p)); | |
259 | ||
260 | return p; | |
261 | } | |
262 | ||
263 | /* | |
264 | * A pfn swap entry is a special type of swap entry that always has a pfn stored | |
265 | * in the swap offset. They are used to represent unaddressable device memory | |
266 | * and to restrict access to a page undergoing migration. | |
267 | */ | |
268 | static inline bool is_pfn_swap_entry(swp_entry_t entry) | |
269 | { | |
b756a3b5 AP |
270 | return is_migration_entry(entry) || is_device_private_entry(entry) || |
271 | is_device_exclusive_entry(entry); | |
af5cdaf8 AP |
272 | } |
273 | ||
616b8371 ZY |
274 | struct page_vma_mapped_walk; |
275 | ||
276 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
277 | extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
278 | struct page *page); | |
279 | ||
280 | extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
281 | struct page *new); | |
282 | ||
283 | extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); | |
284 | ||
285 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
286 | { | |
287 | swp_entry_t arch_entry; | |
288 | ||
ab6e3d09 NH |
289 | if (pmd_swp_soft_dirty(pmd)) |
290 | pmd = pmd_swp_clear_soft_dirty(pmd); | |
8f34f1ea PX |
291 | if (pmd_swp_uffd_wp(pmd)) |
292 | pmd = pmd_swp_clear_uffd_wp(pmd); | |
616b8371 ZY |
293 | arch_entry = __pmd_to_swp_entry(pmd); |
294 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
295 | } | |
296 | ||
297 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
298 | { | |
299 | swp_entry_t arch_entry; | |
300 | ||
301 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
302 | return __swp_entry_to_pmd(arch_entry); | |
303 | } | |
304 | ||
305 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
306 | { | |
307 | return !pmd_present(pmd) && is_migration_entry(pmd_to_swp_entry(pmd)); | |
308 | } | |
309 | #else | |
310 | static inline void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
311 | struct page *page) | |
312 | { | |
313 | BUILD_BUG(); | |
314 | } | |
315 | ||
316 | static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
317 | struct page *new) | |
318 | { | |
319 | BUILD_BUG(); | |
320 | } | |
321 | ||
322 | static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { } | |
323 | ||
324 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
325 | { | |
326 | return swp_entry(0, 0); | |
327 | } | |
328 | ||
329 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
330 | { | |
331 | return __pmd(0); | |
332 | } | |
333 | ||
334 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
335 | { | |
336 | return 0; | |
337 | } | |
338 | #endif | |
339 | ||
a7420aa5 | 340 | #ifdef CONFIG_MEMORY_FAILURE |
8e30456b NH |
341 | |
342 | extern atomic_long_t num_poisoned_pages __read_mostly; | |
343 | ||
a7420aa5 AK |
344 | /* |
345 | * Support for hardware poisoned pages | |
346 | */ | |
347 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
348 | { | |
349 | BUG_ON(!PageLocked(page)); | |
350 | return swp_entry(SWP_HWPOISON, page_to_pfn(page)); | |
351 | } | |
352 | ||
353 | static inline int is_hwpoison_entry(swp_entry_t entry) | |
354 | { | |
355 | return swp_type(entry) == SWP_HWPOISON; | |
356 | } | |
8e30456b | 357 | |
a3f5d80e NH |
358 | static inline unsigned long hwpoison_entry_to_pfn(swp_entry_t entry) |
359 | { | |
360 | return swp_offset(entry); | |
361 | } | |
362 | ||
8e30456b NH |
363 | static inline void num_poisoned_pages_inc(void) |
364 | { | |
365 | atomic_long_inc(&num_poisoned_pages); | |
366 | } | |
367 | ||
368 | static inline void num_poisoned_pages_dec(void) | |
369 | { | |
370 | atomic_long_dec(&num_poisoned_pages); | |
371 | } | |
372 | ||
a7420aa5 AK |
373 | #else |
374 | ||
375 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
376 | { | |
377 | return swp_entry(0, 0); | |
378 | } | |
379 | ||
380 | static inline int is_hwpoison_entry(swp_entry_t swp) | |
381 | { | |
382 | return 0; | |
383 | } | |
da1b13cc | 384 | |
da1b13cc WL |
385 | static inline void num_poisoned_pages_inc(void) |
386 | { | |
387 | } | |
a7420aa5 AK |
388 | #endif |
389 | ||
3f3673d7 SP |
390 | #if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) || \ |
391 | defined(CONFIG_DEVICE_PRIVATE) | |
a7420aa5 AK |
392 | static inline int non_swap_entry(swp_entry_t entry) |
393 | { | |
394 | return swp_type(entry) >= MAX_SWAPFILES; | |
395 | } | |
396 | #else | |
397 | static inline int non_swap_entry(swp_entry_t entry) | |
398 | { | |
399 | return 0; | |
400 | } | |
401 | #endif | |
a2c16d6c | 402 | |
9b98fa22 | 403 | #endif /* CONFIG_MMU */ |
a2c16d6c | 404 | #endif /* _LINUX_SWAPOPS_H */ |