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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> |
a2c16d6c | 7 | |
1da177e4 LT |
8 | /* |
9 | * swapcache pages are stored in the swapper_space radix tree. We want to | |
10 | * get good packing density in that tree, so the index should be dense in | |
11 | * the low-order bits. | |
12 | * | |
9b15b817 | 13 | * We arrange the `type' and `offset' fields so that `type' is at the seven |
e83a9596 | 14 | * high-order bits of the swp_entry_t and `offset' is right-aligned in the |
9b15b817 HD |
15 | * remaining bits. Although `type' itself needs only five bits, we allow for |
16 | * shmem/tmpfs to shift it all up a further two bits: see swp_to_radix_entry(). | |
1da177e4 LT |
17 | * |
18 | * swp_entry_t's are *never* stored anywhere in their arch-dependent format. | |
19 | */ | |
9b15b817 HD |
20 | #define SWP_TYPE_SHIFT(e) ((sizeof(e.val) * 8) - \ |
21 | (MAX_SWAPFILES_SHIFT + RADIX_TREE_EXCEPTIONAL_SHIFT)) | |
1da177e4 LT |
22 | #define SWP_OFFSET_MASK(e) ((1UL << SWP_TYPE_SHIFT(e)) - 1) |
23 | ||
24 | /* | |
25 | * Store a type+offset into a swp_entry_t in an arch-independent format | |
26 | */ | |
27 | static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset) | |
28 | { | |
29 | swp_entry_t ret; | |
30 | ||
31 | ret.val = (type << SWP_TYPE_SHIFT(ret)) | | |
32 | (offset & SWP_OFFSET_MASK(ret)); | |
33 | return ret; | |
34 | } | |
35 | ||
36 | /* | |
37 | * Extract the `type' field from a swp_entry_t. The swp_entry_t is in | |
38 | * arch-independent format | |
39 | */ | |
40 | static inline unsigned swp_type(swp_entry_t entry) | |
41 | { | |
42 | return (entry.val >> SWP_TYPE_SHIFT(entry)); | |
43 | } | |
44 | ||
45 | /* | |
46 | * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in | |
47 | * arch-independent format | |
48 | */ | |
49 | static inline pgoff_t swp_offset(swp_entry_t entry) | |
50 | { | |
51 | return entry.val & SWP_OFFSET_MASK(entry); | |
52 | } | |
53 | ||
880cdf3a | 54 | #ifdef CONFIG_MMU |
698dd4ba MM |
55 | /* check whether a pte points to a swap entry */ |
56 | static inline int is_swap_pte(pte_t pte) | |
57 | { | |
21d9ee3e | 58 | return !pte_none(pte) && !pte_present(pte); |
698dd4ba | 59 | } |
880cdf3a | 60 | #endif |
698dd4ba | 61 | |
1da177e4 LT |
62 | /* |
63 | * Convert the arch-dependent pte representation of a swp_entry_t into an | |
64 | * arch-independent swp_entry_t. | |
65 | */ | |
66 | static inline swp_entry_t pte_to_swp_entry(pte_t pte) | |
67 | { | |
68 | swp_entry_t arch_entry; | |
69 | ||
179ef71c CG |
70 | if (pte_swp_soft_dirty(pte)) |
71 | pte = pte_swp_clear_soft_dirty(pte); | |
1da177e4 LT |
72 | arch_entry = __pte_to_swp_entry(pte); |
73 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
74 | } | |
75 | ||
76 | /* | |
77 | * Convert the arch-independent representation of a swp_entry_t into the | |
78 | * arch-dependent pte representation. | |
79 | */ | |
80 | static inline pte_t swp_entry_to_pte(swp_entry_t entry) | |
81 | { | |
82 | swp_entry_t arch_entry; | |
83 | ||
84 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
1da177e4 LT |
85 | return __swp_entry_to_pte(arch_entry); |
86 | } | |
0697212a | 87 | |
a2c16d6c HD |
88 | static inline swp_entry_t radix_to_swp_entry(void *arg) |
89 | { | |
90 | swp_entry_t entry; | |
91 | ||
92 | entry.val = (unsigned long)arg >> RADIX_TREE_EXCEPTIONAL_SHIFT; | |
93 | return entry; | |
94 | } | |
95 | ||
96 | static inline void *swp_to_radix_entry(swp_entry_t entry) | |
97 | { | |
98 | unsigned long value; | |
99 | ||
100 | value = entry.val << RADIX_TREE_EXCEPTIONAL_SHIFT; | |
101 | return (void *)(value | RADIX_TREE_EXCEPTIONAL_ENTRY); | |
102 | } | |
103 | ||
5042db43 JG |
104 | #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) |
105 | static inline swp_entry_t make_device_private_entry(struct page *page, bool write) | |
106 | { | |
107 | return swp_entry(write ? SWP_DEVICE_WRITE : SWP_DEVICE_READ, | |
108 | page_to_pfn(page)); | |
109 | } | |
110 | ||
111 | static inline bool is_device_private_entry(swp_entry_t entry) | |
112 | { | |
113 | int type = swp_type(entry); | |
114 | return type == SWP_DEVICE_READ || type == SWP_DEVICE_WRITE; | |
115 | } | |
116 | ||
117 | static inline void make_device_private_entry_read(swp_entry_t *entry) | |
118 | { | |
119 | *entry = swp_entry(SWP_DEVICE_READ, swp_offset(*entry)); | |
120 | } | |
121 | ||
122 | static inline bool is_write_device_private_entry(swp_entry_t entry) | |
123 | { | |
124 | return unlikely(swp_type(entry) == SWP_DEVICE_WRITE); | |
125 | } | |
126 | ||
0d665e7b KS |
127 | static inline unsigned long device_private_entry_to_pfn(swp_entry_t entry) |
128 | { | |
129 | return swp_offset(entry); | |
130 | } | |
131 | ||
5042db43 JG |
132 | static inline struct page *device_private_entry_to_page(swp_entry_t entry) |
133 | { | |
134 | return pfn_to_page(swp_offset(entry)); | |
135 | } | |
136 | ||
137 | int device_private_entry_fault(struct vm_area_struct *vma, | |
138 | unsigned long addr, | |
139 | swp_entry_t entry, | |
140 | unsigned int flags, | |
141 | pmd_t *pmdp); | |
142 | #else /* CONFIG_DEVICE_PRIVATE */ | |
143 | static inline swp_entry_t make_device_private_entry(struct page *page, bool write) | |
144 | { | |
145 | return swp_entry(0, 0); | |
146 | } | |
147 | ||
148 | static inline void make_device_private_entry_read(swp_entry_t *entry) | |
149 | { | |
150 | } | |
151 | ||
152 | static inline bool is_device_private_entry(swp_entry_t entry) | |
153 | { | |
154 | return false; | |
155 | } | |
156 | ||
157 | static inline bool is_write_device_private_entry(swp_entry_t entry) | |
158 | { | |
159 | return false; | |
160 | } | |
161 | ||
0d665e7b KS |
162 | static inline unsigned long device_private_entry_to_pfn(swp_entry_t entry) |
163 | { | |
164 | return 0; | |
165 | } | |
166 | ||
5042db43 JG |
167 | static inline struct page *device_private_entry_to_page(swp_entry_t entry) |
168 | { | |
169 | return NULL; | |
170 | } | |
171 | ||
172 | static inline int device_private_entry_fault(struct vm_area_struct *vma, | |
173 | unsigned long addr, | |
174 | swp_entry_t entry, | |
175 | unsigned int flags, | |
176 | pmd_t *pmdp) | |
177 | { | |
178 | return VM_FAULT_SIGBUS; | |
179 | } | |
180 | #endif /* CONFIG_DEVICE_PRIVATE */ | |
181 | ||
0697212a CL |
182 | #ifdef CONFIG_MIGRATION |
183 | static inline swp_entry_t make_migration_entry(struct page *page, int write) | |
184 | { | |
616b8371 ZY |
185 | BUG_ON(!PageLocked(compound_head(page))); |
186 | ||
0697212a CL |
187 | return swp_entry(write ? SWP_MIGRATION_WRITE : SWP_MIGRATION_READ, |
188 | page_to_pfn(page)); | |
189 | } | |
190 | ||
191 | static inline int is_migration_entry(swp_entry_t entry) | |
192 | { | |
193 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ || | |
194 | swp_type(entry) == SWP_MIGRATION_WRITE); | |
195 | } | |
196 | ||
197 | static inline int is_write_migration_entry(swp_entry_t entry) | |
198 | { | |
199 | return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE); | |
200 | } | |
201 | ||
0d665e7b KS |
202 | static inline unsigned long migration_entry_to_pfn(swp_entry_t entry) |
203 | { | |
204 | return swp_offset(entry); | |
205 | } | |
206 | ||
0697212a CL |
207 | static inline struct page *migration_entry_to_page(swp_entry_t entry) |
208 | { | |
209 | struct page *p = pfn_to_page(swp_offset(entry)); | |
210 | /* | |
211 | * Any use of migration entries may only occur while the | |
212 | * corresponding page is locked | |
213 | */ | |
616b8371 | 214 | BUG_ON(!PageLocked(compound_head(p))); |
0697212a CL |
215 | return p; |
216 | } | |
217 | ||
218 | static inline void make_migration_entry_read(swp_entry_t *entry) | |
219 | { | |
220 | *entry = swp_entry(SWP_MIGRATION_READ, swp_offset(*entry)); | |
221 | } | |
222 | ||
e66f17ff NH |
223 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
224 | spinlock_t *ptl); | |
0697212a CL |
225 | extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
226 | unsigned long address); | |
cb900f41 KS |
227 | extern void migration_entry_wait_huge(struct vm_area_struct *vma, |
228 | struct mm_struct *mm, pte_t *pte); | |
0697212a CL |
229 | #else |
230 | ||
231 | #define make_migration_entry(page, write) swp_entry(0, 0) | |
5ec553a9 AM |
232 | static inline int is_migration_entry(swp_entry_t swp) |
233 | { | |
234 | return 0; | |
235 | } | |
0d665e7b KS |
236 | |
237 | static inline unsigned long migration_entry_to_pfn(swp_entry_t entry) | |
238 | { | |
239 | return 0; | |
240 | } | |
241 | ||
616b8371 ZY |
242 | static inline struct page *migration_entry_to_page(swp_entry_t entry) |
243 | { | |
244 | return NULL; | |
245 | } | |
246 | ||
0697212a | 247 | static inline void make_migration_entry_read(swp_entry_t *entryp) { } |
e66f17ff NH |
248 | static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
249 | spinlock_t *ptl) { } | |
0697212a CL |
250 | static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
251 | unsigned long address) { } | |
cb900f41 KS |
252 | static inline void migration_entry_wait_huge(struct vm_area_struct *vma, |
253 | struct mm_struct *mm, pte_t *pte) { } | |
0697212a CL |
254 | static inline int is_write_migration_entry(swp_entry_t entry) |
255 | { | |
256 | return 0; | |
257 | } | |
258 | ||
259 | #endif | |
260 | ||
616b8371 ZY |
261 | struct page_vma_mapped_walk; |
262 | ||
263 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
264 | extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
265 | struct page *page); | |
266 | ||
267 | extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
268 | struct page *new); | |
269 | ||
270 | extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); | |
271 | ||
272 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
273 | { | |
274 | swp_entry_t arch_entry; | |
275 | ||
ab6e3d09 NH |
276 | if (pmd_swp_soft_dirty(pmd)) |
277 | pmd = pmd_swp_clear_soft_dirty(pmd); | |
616b8371 ZY |
278 | arch_entry = __pmd_to_swp_entry(pmd); |
279 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
280 | } | |
281 | ||
282 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
283 | { | |
284 | swp_entry_t arch_entry; | |
285 | ||
286 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
287 | return __swp_entry_to_pmd(arch_entry); | |
288 | } | |
289 | ||
290 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
291 | { | |
292 | return !pmd_present(pmd) && is_migration_entry(pmd_to_swp_entry(pmd)); | |
293 | } | |
294 | #else | |
295 | static inline void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
296 | struct page *page) | |
297 | { | |
298 | BUILD_BUG(); | |
299 | } | |
300 | ||
301 | static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
302 | struct page *new) | |
303 | { | |
304 | BUILD_BUG(); | |
305 | } | |
306 | ||
307 | static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { } | |
308 | ||
309 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
310 | { | |
311 | return swp_entry(0, 0); | |
312 | } | |
313 | ||
314 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
315 | { | |
316 | return __pmd(0); | |
317 | } | |
318 | ||
319 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
320 | { | |
321 | return 0; | |
322 | } | |
323 | #endif | |
324 | ||
a7420aa5 | 325 | #ifdef CONFIG_MEMORY_FAILURE |
8e30456b NH |
326 | |
327 | extern atomic_long_t num_poisoned_pages __read_mostly; | |
328 | ||
a7420aa5 AK |
329 | /* |
330 | * Support for hardware poisoned pages | |
331 | */ | |
332 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
333 | { | |
334 | BUG_ON(!PageLocked(page)); | |
335 | return swp_entry(SWP_HWPOISON, page_to_pfn(page)); | |
336 | } | |
337 | ||
338 | static inline int is_hwpoison_entry(swp_entry_t entry) | |
339 | { | |
340 | return swp_type(entry) == SWP_HWPOISON; | |
341 | } | |
8e30456b | 342 | |
da1b13cc WL |
343 | static inline bool test_set_page_hwpoison(struct page *page) |
344 | { | |
345 | return TestSetPageHWPoison(page); | |
346 | } | |
347 | ||
8e30456b NH |
348 | static inline void num_poisoned_pages_inc(void) |
349 | { | |
350 | atomic_long_inc(&num_poisoned_pages); | |
351 | } | |
352 | ||
353 | static inline void num_poisoned_pages_dec(void) | |
354 | { | |
355 | atomic_long_dec(&num_poisoned_pages); | |
356 | } | |
357 | ||
a7420aa5 AK |
358 | #else |
359 | ||
360 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
361 | { | |
362 | return swp_entry(0, 0); | |
363 | } | |
364 | ||
365 | static inline int is_hwpoison_entry(swp_entry_t swp) | |
366 | { | |
367 | return 0; | |
368 | } | |
da1b13cc WL |
369 | |
370 | static inline bool test_set_page_hwpoison(struct page *page) | |
371 | { | |
372 | return false; | |
373 | } | |
374 | ||
375 | static inline void num_poisoned_pages_inc(void) | |
376 | { | |
377 | } | |
a7420aa5 AK |
378 | #endif |
379 | ||
380 | #if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) | |
381 | static inline int non_swap_entry(swp_entry_t entry) | |
382 | { | |
383 | return swp_type(entry) >= MAX_SWAPFILES; | |
384 | } | |
385 | #else | |
386 | static inline int non_swap_entry(swp_entry_t entry) | |
387 | { | |
388 | return 0; | |
389 | } | |
390 | #endif | |
a2c16d6c HD |
391 | |
392 | #endif /* _LINUX_SWAPOPS_H */ |