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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 | ||
127 | static inline struct page *device_private_entry_to_page(swp_entry_t entry) | |
128 | { | |
129 | return pfn_to_page(swp_offset(entry)); | |
130 | } | |
131 | ||
132 | int device_private_entry_fault(struct vm_area_struct *vma, | |
133 | unsigned long addr, | |
134 | swp_entry_t entry, | |
135 | unsigned int flags, | |
136 | pmd_t *pmdp); | |
137 | #else /* CONFIG_DEVICE_PRIVATE */ | |
138 | static inline swp_entry_t make_device_private_entry(struct page *page, bool write) | |
139 | { | |
140 | return swp_entry(0, 0); | |
141 | } | |
142 | ||
143 | static inline void make_device_private_entry_read(swp_entry_t *entry) | |
144 | { | |
145 | } | |
146 | ||
147 | static inline bool is_device_private_entry(swp_entry_t entry) | |
148 | { | |
149 | return false; | |
150 | } | |
151 | ||
152 | static inline bool is_write_device_private_entry(swp_entry_t entry) | |
153 | { | |
154 | return false; | |
155 | } | |
156 | ||
157 | static inline struct page *device_private_entry_to_page(swp_entry_t entry) | |
158 | { | |
159 | return NULL; | |
160 | } | |
161 | ||
162 | static inline int device_private_entry_fault(struct vm_area_struct *vma, | |
163 | unsigned long addr, | |
164 | swp_entry_t entry, | |
165 | unsigned int flags, | |
166 | pmd_t *pmdp) | |
167 | { | |
168 | return VM_FAULT_SIGBUS; | |
169 | } | |
170 | #endif /* CONFIG_DEVICE_PRIVATE */ | |
171 | ||
0697212a CL |
172 | #ifdef CONFIG_MIGRATION |
173 | static inline swp_entry_t make_migration_entry(struct page *page, int write) | |
174 | { | |
616b8371 ZY |
175 | BUG_ON(!PageLocked(compound_head(page))); |
176 | ||
0697212a CL |
177 | return swp_entry(write ? SWP_MIGRATION_WRITE : SWP_MIGRATION_READ, |
178 | page_to_pfn(page)); | |
179 | } | |
180 | ||
181 | static inline int is_migration_entry(swp_entry_t entry) | |
182 | { | |
183 | return unlikely(swp_type(entry) == SWP_MIGRATION_READ || | |
184 | swp_type(entry) == SWP_MIGRATION_WRITE); | |
185 | } | |
186 | ||
187 | static inline int is_write_migration_entry(swp_entry_t entry) | |
188 | { | |
189 | return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE); | |
190 | } | |
191 | ||
192 | static inline struct page *migration_entry_to_page(swp_entry_t entry) | |
193 | { | |
194 | struct page *p = pfn_to_page(swp_offset(entry)); | |
195 | /* | |
196 | * Any use of migration entries may only occur while the | |
197 | * corresponding page is locked | |
198 | */ | |
616b8371 | 199 | BUG_ON(!PageLocked(compound_head(p))); |
0697212a CL |
200 | return p; |
201 | } | |
202 | ||
203 | static inline void make_migration_entry_read(swp_entry_t *entry) | |
204 | { | |
205 | *entry = swp_entry(SWP_MIGRATION_READ, swp_offset(*entry)); | |
206 | } | |
207 | ||
e66f17ff NH |
208 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
209 | spinlock_t *ptl); | |
0697212a CL |
210 | extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
211 | unsigned long address); | |
cb900f41 KS |
212 | extern void migration_entry_wait_huge(struct vm_area_struct *vma, |
213 | struct mm_struct *mm, pte_t *pte); | |
0697212a CL |
214 | #else |
215 | ||
216 | #define make_migration_entry(page, write) swp_entry(0, 0) | |
5ec553a9 AM |
217 | static inline int is_migration_entry(swp_entry_t swp) |
218 | { | |
219 | return 0; | |
220 | } | |
616b8371 ZY |
221 | static inline struct page *migration_entry_to_page(swp_entry_t entry) |
222 | { | |
223 | return NULL; | |
224 | } | |
225 | ||
0697212a | 226 | static inline void make_migration_entry_read(swp_entry_t *entryp) { } |
e66f17ff NH |
227 | static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
228 | spinlock_t *ptl) { } | |
0697212a CL |
229 | static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
230 | unsigned long address) { } | |
cb900f41 KS |
231 | static inline void migration_entry_wait_huge(struct vm_area_struct *vma, |
232 | struct mm_struct *mm, pte_t *pte) { } | |
0697212a CL |
233 | static inline int is_write_migration_entry(swp_entry_t entry) |
234 | { | |
235 | return 0; | |
236 | } | |
237 | ||
238 | #endif | |
239 | ||
616b8371 ZY |
240 | struct page_vma_mapped_walk; |
241 | ||
242 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION | |
243 | extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
244 | struct page *page); | |
245 | ||
246 | extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
247 | struct page *new); | |
248 | ||
249 | extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd); | |
250 | ||
251 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
252 | { | |
253 | swp_entry_t arch_entry; | |
254 | ||
ab6e3d09 NH |
255 | if (pmd_swp_soft_dirty(pmd)) |
256 | pmd = pmd_swp_clear_soft_dirty(pmd); | |
616b8371 ZY |
257 | arch_entry = __pmd_to_swp_entry(pmd); |
258 | return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); | |
259 | } | |
260 | ||
261 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
262 | { | |
263 | swp_entry_t arch_entry; | |
264 | ||
265 | arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); | |
266 | return __swp_entry_to_pmd(arch_entry); | |
267 | } | |
268 | ||
269 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
270 | { | |
271 | return !pmd_present(pmd) && is_migration_entry(pmd_to_swp_entry(pmd)); | |
272 | } | |
273 | #else | |
274 | static inline void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, | |
275 | struct page *page) | |
276 | { | |
277 | BUILD_BUG(); | |
278 | } | |
279 | ||
280 | static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, | |
281 | struct page *new) | |
282 | { | |
283 | BUILD_BUG(); | |
284 | } | |
285 | ||
286 | static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { } | |
287 | ||
288 | static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd) | |
289 | { | |
290 | return swp_entry(0, 0); | |
291 | } | |
292 | ||
293 | static inline pmd_t swp_entry_to_pmd(swp_entry_t entry) | |
294 | { | |
295 | return __pmd(0); | |
296 | } | |
297 | ||
298 | static inline int is_pmd_migration_entry(pmd_t pmd) | |
299 | { | |
300 | return 0; | |
301 | } | |
302 | #endif | |
303 | ||
a7420aa5 | 304 | #ifdef CONFIG_MEMORY_FAILURE |
8e30456b NH |
305 | |
306 | extern atomic_long_t num_poisoned_pages __read_mostly; | |
307 | ||
a7420aa5 AK |
308 | /* |
309 | * Support for hardware poisoned pages | |
310 | */ | |
311 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
312 | { | |
313 | BUG_ON(!PageLocked(page)); | |
314 | return swp_entry(SWP_HWPOISON, page_to_pfn(page)); | |
315 | } | |
316 | ||
317 | static inline int is_hwpoison_entry(swp_entry_t entry) | |
318 | { | |
319 | return swp_type(entry) == SWP_HWPOISON; | |
320 | } | |
8e30456b | 321 | |
da1b13cc WL |
322 | static inline bool test_set_page_hwpoison(struct page *page) |
323 | { | |
324 | return TestSetPageHWPoison(page); | |
325 | } | |
326 | ||
8e30456b NH |
327 | static inline void num_poisoned_pages_inc(void) |
328 | { | |
329 | atomic_long_inc(&num_poisoned_pages); | |
330 | } | |
331 | ||
332 | static inline void num_poisoned_pages_dec(void) | |
333 | { | |
334 | atomic_long_dec(&num_poisoned_pages); | |
335 | } | |
336 | ||
a7420aa5 AK |
337 | #else |
338 | ||
339 | static inline swp_entry_t make_hwpoison_entry(struct page *page) | |
340 | { | |
341 | return swp_entry(0, 0); | |
342 | } | |
343 | ||
344 | static inline int is_hwpoison_entry(swp_entry_t swp) | |
345 | { | |
346 | return 0; | |
347 | } | |
da1b13cc WL |
348 | |
349 | static inline bool test_set_page_hwpoison(struct page *page) | |
350 | { | |
351 | return false; | |
352 | } | |
353 | ||
354 | static inline void num_poisoned_pages_inc(void) | |
355 | { | |
356 | } | |
a7420aa5 AK |
357 | #endif |
358 | ||
359 | #if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) | |
360 | static inline int non_swap_entry(swp_entry_t entry) | |
361 | { | |
362 | return swp_type(entry) >= MAX_SWAPFILES; | |
363 | } | |
364 | #else | |
365 | static inline int non_swap_entry(swp_entry_t entry) | |
366 | { | |
367 | return 0; | |
368 | } | |
369 | #endif | |
a2c16d6c HD |
370 | |
371 | #endif /* _LINUX_SWAPOPS_H */ |