1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _ASM_GENERIC_PGTABLE_H |
3 | #define _ASM_GENERIC_PGTABLE_H |
4 | |
5 | #include <linux/pfn.h> |
6 | |
7 | #ifndef __ASSEMBLY__ |
8 | #ifdef CONFIG_MMU |
9 | |
10 | #include <linux/mm_types.h> |
11 | #include <linux/bug.h> |
12 | #include <linux/errno.h> |
13 | |
14 | #if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \ |
15 | defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS |
16 | #error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED |
17 | #endif |
18 | |
19 | /* |
20 | * On almost all architectures and configurations, 0 can be used as the |
21 | * upper ceiling to free_pgtables(): on many architectures it has the same |
22 | * effect as using TASK_SIZE. However, there is one configuration which |
23 | * must impose a more careful limit, to avoid freeing kernel pgtables. |
24 | */ |
25 | #ifndef USER_PGTABLES_CEILING |
26 | #define USER_PGTABLES_CEILING 0UL |
27 | #endif |
28 | |
29 | #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS |
30 | extern int ptep_set_access_flags(struct vm_area_struct *vma, |
31 | unsigned long address, pte_t *ptep, |
32 | pte_t entry, int dirty); |
33 | #endif |
34 | |
35 | #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS |
36 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
37 | extern int pmdp_set_access_flags(struct vm_area_struct *vma, |
38 | unsigned long address, pmd_t *pmdp, |
39 | pmd_t entry, int dirty); |
40 | extern int pudp_set_access_flags(struct vm_area_struct *vma, |
41 | unsigned long address, pud_t *pudp, |
42 | pud_t entry, int dirty); |
43 | #else |
44 | static inline int pmdp_set_access_flags(struct vm_area_struct *vma, |
45 | unsigned long address, pmd_t *pmdp, |
46 | pmd_t entry, int dirty) |
47 | { |
48 | BUILD_BUG(); |
49 | return 0; |
50 | } |
51 | static inline int pudp_set_access_flags(struct vm_area_struct *vma, |
52 | unsigned long address, pud_t *pudp, |
53 | pud_t entry, int dirty) |
54 | { |
55 | BUILD_BUG(); |
56 | return 0; |
57 | } |
58 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
59 | #endif |
60 | |
61 | #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG |
62 | static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, |
63 | unsigned long address, |
64 | pte_t *ptep) |
65 | { |
66 | pte_t pte = *ptep; |
67 | int r = 1; |
68 | if (!pte_young(pte)) |
69 | r = 0; |
70 | else |
71 | set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte)); |
72 | return r; |
73 | } |
74 | #endif |
75 | |
76 | #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG |
77 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
78 | static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, |
79 | unsigned long address, |
80 | pmd_t *pmdp) |
81 | { |
82 | pmd_t pmd = *pmdp; |
83 | int r = 1; |
84 | if (!pmd_young(pmd)) |
85 | r = 0; |
86 | else |
87 | set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd)); |
88 | return r; |
89 | } |
90 | #else |
91 | static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, |
92 | unsigned long address, |
93 | pmd_t *pmdp) |
94 | { |
95 | BUILD_BUG(); |
96 | return 0; |
97 | } |
98 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
99 | #endif |
100 | |
101 | #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH |
102 | int ptep_clear_flush_young(struct vm_area_struct *vma, |
103 | unsigned long address, pte_t *ptep); |
104 | #endif |
105 | |
106 | #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH |
107 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
108 | extern int pmdp_clear_flush_young(struct vm_area_struct *vma, |
109 | unsigned long address, pmd_t *pmdp); |
110 | #else |
111 | /* |
112 | * Despite relevant to THP only, this API is called from generic rmap code |
113 | * under PageTransHuge(), hence needs a dummy implementation for !THP |
114 | */ |
115 | static inline int pmdp_clear_flush_young(struct vm_area_struct *vma, |
116 | unsigned long address, pmd_t *pmdp) |
117 | { |
118 | BUILD_BUG(); |
119 | return 0; |
120 | } |
121 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
122 | #endif |
123 | |
124 | #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR |
125 | static inline pte_t ptep_get_and_clear(struct mm_struct *mm, |
126 | unsigned long address, |
127 | pte_t *ptep) |
128 | { |
129 | pte_t pte = *ptep; |
130 | pte_clear(mm, address, ptep); |
131 | return pte; |
132 | } |
133 | #endif |
134 | |
135 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
136 | #ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR |
137 | static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, |
138 | unsigned long address, |
139 | pmd_t *pmdp) |
140 | { |
141 | pmd_t pmd = *pmdp; |
142 | pmd_clear(pmdp); |
143 | return pmd; |
144 | } |
145 | #endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */ |
146 | #ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR |
147 | static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, |
148 | unsigned long address, |
149 | pud_t *pudp) |
150 | { |
151 | pud_t pud = *pudp; |
152 | |
153 | pud_clear(pudp); |
154 | return pud; |
155 | } |
156 | #endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */ |
157 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
158 | |
159 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
160 | #ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL |
161 | static inline pmd_t pmdp_huge_get_and_clear_full(struct mm_struct *mm, |
162 | unsigned long address, pmd_t *pmdp, |
163 | int full) |
164 | { |
165 | return pmdp_huge_get_and_clear(mm, address, pmdp); |
166 | } |
167 | #endif |
168 | |
169 | #ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL |
170 | static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm, |
171 | unsigned long address, pud_t *pudp, |
172 | int full) |
173 | { |
174 | return pudp_huge_get_and_clear(mm, address, pudp); |
175 | } |
176 | #endif |
177 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
178 | |
179 | #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL |
180 | static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, |
181 | unsigned long address, pte_t *ptep, |
182 | int full) |
183 | { |
184 | pte_t pte; |
185 | pte = ptep_get_and_clear(mm, address, ptep); |
186 | return pte; |
187 | } |
188 | #endif |
189 | |
190 | /* |
191 | * Some architectures may be able to avoid expensive synchronization |
192 | * primitives when modifications are made to PTE's which are already |
193 | * not present, or in the process of an address space destruction. |
194 | */ |
195 | #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL |
196 | static inline void pte_clear_not_present_full(struct mm_struct *mm, |
197 | unsigned long address, |
198 | pte_t *ptep, |
199 | int full) |
200 | { |
201 | pte_clear(mm, address, ptep); |
202 | } |
203 | #endif |
204 | |
205 | #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH |
206 | extern pte_t ptep_clear_flush(struct vm_area_struct *vma, |
207 | unsigned long address, |
208 | pte_t *ptep); |
209 | #endif |
210 | |
211 | #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH |
212 | extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, |
213 | unsigned long address, |
214 | pmd_t *pmdp); |
215 | extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, |
216 | unsigned long address, |
217 | pud_t *pudp); |
218 | #endif |
219 | |
220 | #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT |
221 | struct mm_struct; |
222 | static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep) |
223 | { |
224 | pte_t old_pte = *ptep; |
225 | set_pte_at(mm, address, ptep, pte_wrprotect(old_pte)); |
226 | } |
227 | #endif |
228 | |
229 | #ifndef pte_savedwrite |
230 | #define pte_savedwrite pte_write |
231 | #endif |
232 | |
233 | #ifndef pte_mk_savedwrite |
234 | #define pte_mk_savedwrite pte_mkwrite |
235 | #endif |
236 | |
237 | #ifndef pte_clear_savedwrite |
238 | #define pte_clear_savedwrite pte_wrprotect |
239 | #endif |
240 | |
241 | #ifndef pmd_savedwrite |
242 | #define pmd_savedwrite pmd_write |
243 | #endif |
244 | |
245 | #ifndef pmd_mk_savedwrite |
246 | #define pmd_mk_savedwrite pmd_mkwrite |
247 | #endif |
248 | |
249 | #ifndef pmd_clear_savedwrite |
250 | #define pmd_clear_savedwrite pmd_wrprotect |
251 | #endif |
252 | |
253 | #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT |
254 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
255 | static inline void pmdp_set_wrprotect(struct mm_struct *mm, |
256 | unsigned long address, pmd_t *pmdp) |
257 | { |
258 | pmd_t old_pmd = *pmdp; |
259 | set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd)); |
260 | } |
261 | #else |
262 | static inline void pmdp_set_wrprotect(struct mm_struct *mm, |
263 | unsigned long address, pmd_t *pmdp) |
264 | { |
265 | BUILD_BUG(); |
266 | } |
267 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
268 | #endif |
269 | #ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT |
270 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
271 | static inline void pudp_set_wrprotect(struct mm_struct *mm, |
272 | unsigned long address, pud_t *pudp) |
273 | { |
274 | pud_t old_pud = *pudp; |
275 | |
276 | set_pud_at(mm, address, pudp, pud_wrprotect(old_pud)); |
277 | } |
278 | #else |
279 | static inline void pudp_set_wrprotect(struct mm_struct *mm, |
280 | unsigned long address, pud_t *pudp) |
281 | { |
282 | BUILD_BUG(); |
283 | } |
284 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
285 | #endif |
286 | |
287 | #ifndef pmdp_collapse_flush |
288 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
289 | extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, |
290 | unsigned long address, pmd_t *pmdp); |
291 | #else |
292 | static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, |
293 | unsigned long address, |
294 | pmd_t *pmdp) |
295 | { |
296 | BUILD_BUG(); |
297 | return *pmdp; |
298 | } |
299 | #define pmdp_collapse_flush pmdp_collapse_flush |
300 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
301 | #endif |
302 | |
303 | #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT |
304 | extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, |
305 | pgtable_t pgtable); |
306 | #endif |
307 | |
308 | #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW |
309 | extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); |
310 | #endif |
311 | |
312 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
313 | /* |
314 | * This is an implementation of pmdp_establish() that is only suitable for an |
315 | * architecture that doesn't have hardware dirty/accessed bits. In this case we |
316 | * can't race with CPU which sets these bits and non-atomic aproach is fine. |
317 | */ |
318 | static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma, |
319 | unsigned long address, pmd_t *pmdp, pmd_t pmd) |
320 | { |
321 | pmd_t old_pmd = *pmdp; |
322 | set_pmd_at(vma->vm_mm, address, pmdp, pmd); |
323 | return old_pmd; |
324 | } |
325 | #endif |
326 | |
327 | #ifndef __HAVE_ARCH_PMDP_INVALIDATE |
328 | extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, |
329 | pmd_t *pmdp); |
330 | #endif |
331 | |
332 | #ifndef __HAVE_ARCH_PTE_SAME |
333 | static inline int pte_same(pte_t pte_a, pte_t pte_b) |
334 | { |
335 | return pte_val(pte_a) == pte_val(pte_b); |
336 | } |
337 | #endif |
338 | |
339 | #ifndef __HAVE_ARCH_PTE_UNUSED |
340 | /* |
341 | * Some architectures provide facilities to virtualization guests |
342 | * so that they can flag allocated pages as unused. This allows the |
343 | * host to transparently reclaim unused pages. This function returns |
344 | * whether the pte's page is unused. |
345 | */ |
346 | static inline int pte_unused(pte_t pte) |
347 | { |
348 | return 0; |
349 | } |
350 | #endif |
351 | |
352 | #ifndef pte_access_permitted |
353 | #define pte_access_permitted(pte, write) \ |
354 | (pte_present(pte) && (!(write) || pte_write(pte))) |
355 | #endif |
356 | |
357 | #ifndef pmd_access_permitted |
358 | #define pmd_access_permitted(pmd, write) \ |
359 | (pmd_present(pmd) && (!(write) || pmd_write(pmd))) |
360 | #endif |
361 | |
362 | #ifndef pud_access_permitted |
363 | #define pud_access_permitted(pud, write) \ |
364 | (pud_present(pud) && (!(write) || pud_write(pud))) |
365 | #endif |
366 | |
367 | #ifndef p4d_access_permitted |
368 | #define p4d_access_permitted(p4d, write) \ |
369 | (p4d_present(p4d) && (!(write) || p4d_write(p4d))) |
370 | #endif |
371 | |
372 | #ifndef pgd_access_permitted |
373 | #define pgd_access_permitted(pgd, write) \ |
374 | (pgd_present(pgd) && (!(write) || pgd_write(pgd))) |
375 | #endif |
376 | |
377 | #ifndef __HAVE_ARCH_PMD_SAME |
378 | static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) |
379 | { |
380 | return pmd_val(pmd_a) == pmd_val(pmd_b); |
381 | } |
382 | |
383 | static inline int pud_same(pud_t pud_a, pud_t pud_b) |
384 | { |
385 | return pud_val(pud_a) == pud_val(pud_b); |
386 | } |
387 | #endif |
388 | |
389 | #ifndef __HAVE_ARCH_P4D_SAME |
390 | static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b) |
391 | { |
392 | return p4d_val(p4d_a) == p4d_val(p4d_b); |
393 | } |
394 | #endif |
395 | |
396 | #ifndef __HAVE_ARCH_PGD_SAME |
397 | static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b) |
398 | { |
399 | return pgd_val(pgd_a) == pgd_val(pgd_b); |
400 | } |
401 | #endif |
402 | |
403 | /* |
404 | * Use set_p*_safe(), and elide TLB flushing, when confident that *no* |
405 | * TLB flush will be required as a result of the "set". For example, use |
406 | * in scenarios where it is known ahead of time that the routine is |
407 | * setting non-present entries, or re-setting an existing entry to the |
408 | * same value. Otherwise, use the typical "set" helpers and flush the |
409 | * TLB. |
410 | */ |
411 | #define set_pte_safe(ptep, pte) \ |
412 | ({ \ |
413 | WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ |
414 | set_pte(ptep, pte); \ |
415 | }) |
416 | |
417 | #define set_pmd_safe(pmdp, pmd) \ |
418 | ({ \ |
419 | WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ |
420 | set_pmd(pmdp, pmd); \ |
421 | }) |
422 | |
423 | #define set_pud_safe(pudp, pud) \ |
424 | ({ \ |
425 | WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ |
426 | set_pud(pudp, pud); \ |
427 | }) |
428 | |
429 | #define set_p4d_safe(p4dp, p4d) \ |
430 | ({ \ |
431 | WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ |
432 | set_p4d(p4dp, p4d); \ |
433 | }) |
434 | |
435 | #define set_pgd_safe(pgdp, pgd) \ |
436 | ({ \ |
437 | WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ |
438 | set_pgd(pgdp, pgd); \ |
439 | }) |
440 | |
441 | #ifndef __HAVE_ARCH_DO_SWAP_PAGE |
442 | /* |
443 | * Some architectures support metadata associated with a page. When a |
444 | * page is being swapped out, this metadata must be saved so it can be |
445 | * restored when the page is swapped back in. SPARC M7 and newer |
446 | * processors support an ADI (Application Data Integrity) tag for the |
447 | * page as metadata for the page. arch_do_swap_page() can restore this |
448 | * metadata when a page is swapped back in. |
449 | */ |
450 | static inline void arch_do_swap_page(struct mm_struct *mm, |
451 | struct vm_area_struct *vma, |
452 | unsigned long addr, |
453 | pte_t pte, pte_t oldpte) |
454 | { |
455 | |
456 | } |
457 | #endif |
458 | |
459 | #ifndef __HAVE_ARCH_UNMAP_ONE |
460 | /* |
461 | * Some architectures support metadata associated with a page. When a |
462 | * page is being swapped out, this metadata must be saved so it can be |
463 | * restored when the page is swapped back in. SPARC M7 and newer |
464 | * processors support an ADI (Application Data Integrity) tag for the |
465 | * page as metadata for the page. arch_unmap_one() can save this |
466 | * metadata on a swap-out of a page. |
467 | */ |
468 | static inline int arch_unmap_one(struct mm_struct *mm, |
469 | struct vm_area_struct *vma, |
470 | unsigned long addr, |
471 | pte_t orig_pte) |
472 | { |
473 | return 0; |
474 | } |
475 | #endif |
476 | |
477 | #ifndef __HAVE_ARCH_PGD_OFFSET_GATE |
478 | #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr) |
479 | #endif |
480 | |
481 | #ifndef __HAVE_ARCH_MOVE_PTE |
482 | #define move_pte(pte, prot, old_addr, new_addr) (pte) |
483 | #endif |
484 | |
485 | #ifndef pte_accessible |
486 | # define pte_accessible(mm, pte) ((void)(pte), 1) |
487 | #endif |
488 | |
489 | #ifndef flush_tlb_fix_spurious_fault |
490 | #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address) |
491 | #endif |
492 | |
493 | #ifndef pgprot_noncached |
494 | #define pgprot_noncached(prot) (prot) |
495 | #endif |
496 | |
497 | #ifndef pgprot_writecombine |
498 | #define pgprot_writecombine pgprot_noncached |
499 | #endif |
500 | |
501 | #ifndef pgprot_writethrough |
502 | #define pgprot_writethrough pgprot_noncached |
503 | #endif |
504 | |
505 | #ifndef pgprot_device |
506 | #define pgprot_device pgprot_noncached |
507 | #endif |
508 | |
509 | #ifndef pgprot_modify |
510 | #define pgprot_modify pgprot_modify |
511 | static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) |
512 | { |
513 | if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot))) |
514 | newprot = pgprot_noncached(newprot); |
515 | if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot))) |
516 | newprot = pgprot_writecombine(newprot); |
517 | if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot))) |
518 | newprot = pgprot_device(newprot); |
519 | return newprot; |
520 | } |
521 | #endif |
522 | |
523 | /* |
524 | * When walking page tables, get the address of the next boundary, |
525 | * or the end address of the range if that comes earlier. Although no |
526 | * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout. |
527 | */ |
528 | |
529 | #define pgd_addr_end(addr, end) \ |
530 | ({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ |
531 | (__boundary - 1 < (end) - 1)? __boundary: (end); \ |
532 | }) |
533 | |
534 | #ifndef p4d_addr_end |
535 | #define p4d_addr_end(addr, end) \ |
536 | ({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \ |
537 | (__boundary - 1 < (end) - 1)? __boundary: (end); \ |
538 | }) |
539 | #endif |
540 | |
541 | #ifndef pud_addr_end |
542 | #define pud_addr_end(addr, end) \ |
543 | ({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \ |
544 | (__boundary - 1 < (end) - 1)? __boundary: (end); \ |
545 | }) |
546 | #endif |
547 | |
548 | #ifndef pmd_addr_end |
549 | #define pmd_addr_end(addr, end) \ |
550 | ({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \ |
551 | (__boundary - 1 < (end) - 1)? __boundary: (end); \ |
552 | }) |
553 | #endif |
554 | |
555 | /* |
556 | * When walking page tables, we usually want to skip any p?d_none entries; |
557 | * and any p?d_bad entries - reporting the error before resetting to none. |
558 | * Do the tests inline, but report and clear the bad entry in mm/memory.c. |
559 | */ |
560 | void pgd_clear_bad(pgd_t *); |
561 | void p4d_clear_bad(p4d_t *); |
562 | void pud_clear_bad(pud_t *); |
563 | void pmd_clear_bad(pmd_t *); |
564 | |
565 | static inline int pgd_none_or_clear_bad(pgd_t *pgd) |
566 | { |
567 | if (pgd_none(*pgd)) |
568 | return 1; |
569 | if (unlikely(pgd_bad(*pgd))) { |
570 | pgd_clear_bad(pgd); |
571 | return 1; |
572 | } |
573 | return 0; |
574 | } |
575 | |
576 | static inline int p4d_none_or_clear_bad(p4d_t *p4d) |
577 | { |
578 | if (p4d_none(*p4d)) |
579 | return 1; |
580 | if (unlikely(p4d_bad(*p4d))) { |
581 | p4d_clear_bad(p4d); |
582 | return 1; |
583 | } |
584 | return 0; |
585 | } |
586 | |
587 | static inline int pud_none_or_clear_bad(pud_t *pud) |
588 | { |
589 | if (pud_none(*pud)) |
590 | return 1; |
591 | if (unlikely(pud_bad(*pud))) { |
592 | pud_clear_bad(pud); |
593 | return 1; |
594 | } |
595 | return 0; |
596 | } |
597 | |
598 | static inline int pmd_none_or_clear_bad(pmd_t *pmd) |
599 | { |
600 | if (pmd_none(*pmd)) |
601 | return 1; |
602 | if (unlikely(pmd_bad(*pmd))) { |
603 | pmd_clear_bad(pmd); |
604 | return 1; |
605 | } |
606 | return 0; |
607 | } |
608 | |
609 | static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma, |
610 | unsigned long addr, |
611 | pte_t *ptep) |
612 | { |
613 | /* |
614 | * Get the current pte state, but zero it out to make it |
615 | * non-present, preventing the hardware from asynchronously |
616 | * updating it. |
617 | */ |
618 | return ptep_get_and_clear(vma->vm_mm, addr, ptep); |
619 | } |
620 | |
621 | static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma, |
622 | unsigned long addr, |
623 | pte_t *ptep, pte_t pte) |
624 | { |
625 | /* |
626 | * The pte is non-present, so there's no hardware state to |
627 | * preserve. |
628 | */ |
629 | set_pte_at(vma->vm_mm, addr, ptep, pte); |
630 | } |
631 | |
632 | #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION |
633 | /* |
634 | * Start a pte protection read-modify-write transaction, which |
635 | * protects against asynchronous hardware modifications to the pte. |
636 | * The intention is not to prevent the hardware from making pte |
637 | * updates, but to prevent any updates it may make from being lost. |
638 | * |
639 | * This does not protect against other software modifications of the |
640 | * pte; the appropriate pte lock must be held over the transation. |
641 | * |
642 | * Note that this interface is intended to be batchable, meaning that |
643 | * ptep_modify_prot_commit may not actually update the pte, but merely |
644 | * queue the update to be done at some later time. The update must be |
645 | * actually committed before the pte lock is released, however. |
646 | */ |
647 | static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma, |
648 | unsigned long addr, |
649 | pte_t *ptep) |
650 | { |
651 | return __ptep_modify_prot_start(vma, addr, ptep); |
652 | } |
653 | |
654 | /* |
655 | * Commit an update to a pte, leaving any hardware-controlled bits in |
656 | * the PTE unmodified. |
657 | */ |
658 | static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, |
659 | unsigned long addr, |
660 | pte_t *ptep, pte_t old_pte, pte_t pte) |
661 | { |
662 | __ptep_modify_prot_commit(vma, addr, ptep, pte); |
663 | } |
664 | #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ |
665 | #endif /* CONFIG_MMU */ |
666 | |
667 | /* |
668 | * No-op macros that just return the current protection value. Defined here |
669 | * because these macros can be used used even if CONFIG_MMU is not defined. |
670 | */ |
671 | #ifndef pgprot_encrypted |
672 | #define pgprot_encrypted(prot) (prot) |
673 | #endif |
674 | |
675 | #ifndef pgprot_decrypted |
676 | #define pgprot_decrypted(prot) (prot) |
677 | #endif |
678 | |
679 | /* |
680 | * A facility to provide lazy MMU batching. This allows PTE updates and |
681 | * page invalidations to be delayed until a call to leave lazy MMU mode |
682 | * is issued. Some architectures may benefit from doing this, and it is |
683 | * beneficial for both shadow and direct mode hypervisors, which may batch |
684 | * the PTE updates which happen during this window. Note that using this |
685 | * interface requires that read hazards be removed from the code. A read |
686 | * hazard could result in the direct mode hypervisor case, since the actual |
687 | * write to the page tables may not yet have taken place, so reads though |
688 | * a raw PTE pointer after it has been modified are not guaranteed to be |
689 | * up to date. This mode can only be entered and left under the protection of |
690 | * the page table locks for all page tables which may be modified. In the UP |
691 | * case, this is required so that preemption is disabled, and in the SMP case, |
692 | * it must synchronize the delayed page table writes properly on other CPUs. |
693 | */ |
694 | #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE |
695 | #define arch_enter_lazy_mmu_mode() do {} while (0) |
696 | #define arch_leave_lazy_mmu_mode() do {} while (0) |
697 | #define arch_flush_lazy_mmu_mode() do {} while (0) |
698 | #endif |
699 | |
700 | /* |
701 | * A facility to provide batching of the reload of page tables and |
702 | * other process state with the actual context switch code for |
703 | * paravirtualized guests. By convention, only one of the batched |
704 | * update (lazy) modes (CPU, MMU) should be active at any given time, |
705 | * entry should never be nested, and entry and exits should always be |
706 | * paired. This is for sanity of maintaining and reasoning about the |
707 | * kernel code. In this case, the exit (end of the context switch) is |
708 | * in architecture-specific code, and so doesn't need a generic |
709 | * definition. |
710 | */ |
711 | #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH |
712 | #define arch_start_context_switch(prev) do {} while (0) |
713 | #endif |
714 | |
715 | #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY |
716 | #ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION |
717 | static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) |
718 | { |
719 | return pmd; |
720 | } |
721 | |
722 | static inline int pmd_swp_soft_dirty(pmd_t pmd) |
723 | { |
724 | return 0; |
725 | } |
726 | |
727 | static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) |
728 | { |
729 | return pmd; |
730 | } |
731 | #endif |
732 | #else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */ |
733 | static inline int pte_soft_dirty(pte_t pte) |
734 | { |
735 | return 0; |
736 | } |
737 | |
738 | static inline int pmd_soft_dirty(pmd_t pmd) |
739 | { |
740 | return 0; |
741 | } |
742 | |
743 | static inline pte_t pte_mksoft_dirty(pte_t pte) |
744 | { |
745 | return pte; |
746 | } |
747 | |
748 | static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) |
749 | { |
750 | return pmd; |
751 | } |
752 | |
753 | static inline pte_t pte_clear_soft_dirty(pte_t pte) |
754 | { |
755 | return pte; |
756 | } |
757 | |
758 | static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) |
759 | { |
760 | return pmd; |
761 | } |
762 | |
763 | static inline pte_t pte_swp_mksoft_dirty(pte_t pte) |
764 | { |
765 | return pte; |
766 | } |
767 | |
768 | static inline int pte_swp_soft_dirty(pte_t pte) |
769 | { |
770 | return 0; |
771 | } |
772 | |
773 | static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) |
774 | { |
775 | return pte; |
776 | } |
777 | |
778 | static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) |
779 | { |
780 | return pmd; |
781 | } |
782 | |
783 | static inline int pmd_swp_soft_dirty(pmd_t pmd) |
784 | { |
785 | return 0; |
786 | } |
787 | |
788 | static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) |
789 | { |
790 | return pmd; |
791 | } |
792 | #endif |
793 | |
794 | #ifndef __HAVE_PFNMAP_TRACKING |
795 | /* |
796 | * Interfaces that can be used by architecture code to keep track of |
797 | * memory type of pfn mappings specified by the remap_pfn_range, |
798 | * vmf_insert_pfn. |
799 | */ |
800 | |
801 | /* |
802 | * track_pfn_remap is called when a _new_ pfn mapping is being established |
803 | * by remap_pfn_range() for physical range indicated by pfn and size. |
804 | */ |
805 | static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, |
806 | unsigned long pfn, unsigned long addr, |
807 | unsigned long size) |
808 | { |
809 | return 0; |
810 | } |
811 | |
812 | /* |
813 | * track_pfn_insert is called when a _new_ single pfn is established |
814 | * by vmf_insert_pfn(). |
815 | */ |
816 | static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, |
817 | pfn_t pfn) |
818 | { |
819 | } |
820 | |
821 | /* |
822 | * track_pfn_copy is called when vma that is covering the pfnmap gets |
823 | * copied through copy_page_range(). |
824 | */ |
825 | static inline int track_pfn_copy(struct vm_area_struct *vma) |
826 | { |
827 | return 0; |
828 | } |
829 | |
830 | /* |
831 | * untrack_pfn is called while unmapping a pfnmap for a region. |
832 | * untrack can be called for a specific region indicated by pfn and size or |
833 | * can be for the entire vma (in which case pfn, size are zero). |
834 | */ |
835 | static inline void untrack_pfn(struct vm_area_struct *vma, |
836 | unsigned long pfn, unsigned long size) |
837 | { |
838 | } |
839 | |
840 | /* |
841 | * untrack_pfn_moved is called while mremapping a pfnmap for a new region. |
842 | */ |
843 | static inline void untrack_pfn_moved(struct vm_area_struct *vma) |
844 | { |
845 | } |
846 | #else |
847 | extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, |
848 | unsigned long pfn, unsigned long addr, |
849 | unsigned long size); |
850 | extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, |
851 | pfn_t pfn); |
852 | extern int track_pfn_copy(struct vm_area_struct *vma); |
853 | extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, |
854 | unsigned long size); |
855 | extern void untrack_pfn_moved(struct vm_area_struct *vma); |
856 | #endif |
857 | |
858 | #ifdef __HAVE_COLOR_ZERO_PAGE |
859 | static inline int is_zero_pfn(unsigned long pfn) |
860 | { |
861 | extern unsigned long zero_pfn; |
862 | unsigned long offset_from_zero_pfn = pfn - zero_pfn; |
863 | return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); |
864 | } |
865 | |
866 | #define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) |
867 | |
868 | #else |
869 | static inline int is_zero_pfn(unsigned long pfn) |
870 | { |
871 | extern unsigned long zero_pfn; |
872 | return pfn == zero_pfn; |
873 | } |
874 | |
875 | static inline unsigned long my_zero_pfn(unsigned long addr) |
876 | { |
877 | extern unsigned long zero_pfn; |
878 | return zero_pfn; |
879 | } |
880 | #endif |
881 | |
882 | #ifdef CONFIG_MMU |
883 | |
884 | #ifndef CONFIG_TRANSPARENT_HUGEPAGE |
885 | static inline int pmd_trans_huge(pmd_t pmd) |
886 | { |
887 | return 0; |
888 | } |
889 | #ifndef pmd_write |
890 | static inline int pmd_write(pmd_t pmd) |
891 | { |
892 | BUG(); |
893 | return 0; |
894 | } |
895 | #endif /* pmd_write */ |
896 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
897 | |
898 | #ifndef pud_write |
899 | static inline int pud_write(pud_t pud) |
900 | { |
901 | BUG(); |
902 | return 0; |
903 | } |
904 | #endif /* pud_write */ |
905 | |
906 | #if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \ |
907 | (defined(CONFIG_TRANSPARENT_HUGEPAGE) && \ |
908 | !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) |
909 | static inline int pud_trans_huge(pud_t pud) |
910 | { |
911 | return 0; |
912 | } |
913 | #endif |
914 | |
915 | #ifndef pmd_read_atomic |
916 | static inline pmd_t pmd_read_atomic(pmd_t *pmdp) |
917 | { |
918 | /* |
919 | * Depend on compiler for an atomic pmd read. NOTE: this is |
920 | * only going to work, if the pmdval_t isn't larger than |
921 | * an unsigned long. |
922 | */ |
923 | return *pmdp; |
924 | } |
925 | #endif |
926 | |
927 | #ifndef arch_needs_pgtable_deposit |
928 | #define arch_needs_pgtable_deposit() (false) |
929 | #endif |
930 | /* |
931 | * This function is meant to be used by sites walking pagetables with |
932 | * the mmap_sem hold in read mode to protect against MADV_DONTNEED and |
933 | * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd |
934 | * into a null pmd and the transhuge page fault can convert a null pmd |
935 | * into an hugepmd or into a regular pmd (if the hugepage allocation |
936 | * fails). While holding the mmap_sem in read mode the pmd becomes |
937 | * stable and stops changing under us only if it's not null and not a |
938 | * transhuge pmd. When those races occurs and this function makes a |
939 | * difference vs the standard pmd_none_or_clear_bad, the result is |
940 | * undefined so behaving like if the pmd was none is safe (because it |
941 | * can return none anyway). The compiler level barrier() is critically |
942 | * important to compute the two checks atomically on the same pmdval. |
943 | * |
944 | * For 32bit kernels with a 64bit large pmd_t this automatically takes |
945 | * care of reading the pmd atomically to avoid SMP race conditions |
946 | * against pmd_populate() when the mmap_sem is hold for reading by the |
947 | * caller (a special atomic read not done by "gcc" as in the generic |
948 | * version above, is also needed when THP is disabled because the page |
949 | * fault can populate the pmd from under us). |
950 | */ |
951 | static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd) |
952 | { |
953 | pmd_t pmdval = pmd_read_atomic(pmd); |
954 | /* |
955 | * The barrier will stabilize the pmdval in a register or on |
956 | * the stack so that it will stop changing under the code. |
957 | * |
958 | * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE, |
959 | * pmd_read_atomic is allowed to return a not atomic pmdval |
960 | * (for example pointing to an hugepage that has never been |
961 | * mapped in the pmd). The below checks will only care about |
962 | * the low part of the pmd with 32bit PAE x86 anyway, with the |
963 | * exception of pmd_none(). So the important thing is that if |
964 | * the low part of the pmd is found null, the high part will |
965 | * be also null or the pmd_none() check below would be |
966 | * confused. |
967 | */ |
968 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
969 | barrier(); |
970 | #endif |
971 | /* |
972 | * !pmd_present() checks for pmd migration entries |
973 | * |
974 | * The complete check uses is_pmd_migration_entry() in linux/swapops.h |
975 | * But using that requires moving current function and pmd_trans_unstable() |
976 | * to linux/swapops.h to resovle dependency, which is too much code move. |
977 | * |
978 | * !pmd_present() is equivalent to is_pmd_migration_entry() currently, |
979 | * because !pmd_present() pages can only be under migration not swapped |
980 | * out. |
981 | * |
982 | * pmd_none() is preseved for future condition checks on pmd migration |
983 | * entries and not confusing with this function name, although it is |
984 | * redundant with !pmd_present(). |
985 | */ |
986 | if (pmd_none(pmdval) || pmd_trans_huge(pmdval) || |
987 | (IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval))) |
988 | return 1; |
989 | if (unlikely(pmd_bad(pmdval))) { |
990 | pmd_clear_bad(pmd); |
991 | return 1; |
992 | } |
993 | return 0; |
994 | } |
995 | |
996 | /* |
997 | * This is a noop if Transparent Hugepage Support is not built into |
998 | * the kernel. Otherwise it is equivalent to |
999 | * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in |
1000 | * places that already verified the pmd is not none and they want to |
1001 | * walk ptes while holding the mmap sem in read mode (write mode don't |
1002 | * need this). If THP is not enabled, the pmd can't go away under the |
1003 | * code even if MADV_DONTNEED runs, but if THP is enabled we need to |
1004 | * run a pmd_trans_unstable before walking the ptes after |
1005 | * split_huge_page_pmd returns (because it may have run when the pmd |
1006 | * become null, but then a page fault can map in a THP and not a |
1007 | * regular page). |
1008 | */ |
1009 | static inline int pmd_trans_unstable(pmd_t *pmd) |
1010 | { |
1011 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
1012 | return pmd_none_or_trans_huge_or_clear_bad(pmd); |
1013 | #else |
1014 | return 0; |
1015 | #endif |
1016 | } |
1017 | |
1018 | #ifndef CONFIG_NUMA_BALANCING |
1019 | /* |
1020 | * Technically a PTE can be PROTNONE even when not doing NUMA balancing but |
1021 | * the only case the kernel cares is for NUMA balancing and is only ever set |
1022 | * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked |
1023 | * _PAGE_PROTNONE so by by default, implement the helper as "always no". It |
1024 | * is the responsibility of the caller to distinguish between PROT_NONE |
1025 | * protections and NUMA hinting fault protections. |
1026 | */ |
1027 | static inline int pte_protnone(pte_t pte) |
1028 | { |
1029 | return 0; |
1030 | } |
1031 | |
1032 | static inline int pmd_protnone(pmd_t pmd) |
1033 | { |
1034 | return 0; |
1035 | } |
1036 | #endif /* CONFIG_NUMA_BALANCING */ |
1037 | |
1038 | #endif /* CONFIG_MMU */ |
1039 | |
1040 | #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP |
1041 | |
1042 | #ifndef __PAGETABLE_P4D_FOLDED |
1043 | int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot); |
1044 | int p4d_clear_huge(p4d_t *p4d); |
1045 | #else |
1046 | static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot) |
1047 | { |
1048 | return 0; |
1049 | } |
1050 | static inline int p4d_clear_huge(p4d_t *p4d) |
1051 | { |
1052 | return 0; |
1053 | } |
1054 | #endif /* !__PAGETABLE_P4D_FOLDED */ |
1055 | |
1056 | int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot); |
1057 | int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot); |
1058 | int pud_clear_huge(pud_t *pud); |
1059 | int pmd_clear_huge(pmd_t *pmd); |
1060 | int p4d_free_pud_page(p4d_t *p4d, unsigned long addr); |
1061 | int pud_free_pmd_page(pud_t *pud, unsigned long addr); |
1062 | int pmd_free_pte_page(pmd_t *pmd, unsigned long addr); |
1063 | #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ |
1064 | static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot) |
1065 | { |
1066 | return 0; |
1067 | } |
1068 | static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) |
1069 | { |
1070 | return 0; |
1071 | } |
1072 | static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) |
1073 | { |
1074 | return 0; |
1075 | } |
1076 | static inline int p4d_clear_huge(p4d_t *p4d) |
1077 | { |
1078 | return 0; |
1079 | } |
1080 | static inline int pud_clear_huge(pud_t *pud) |
1081 | { |
1082 | return 0; |
1083 | } |
1084 | static inline int pmd_clear_huge(pmd_t *pmd) |
1085 | { |
1086 | return 0; |
1087 | } |
1088 | static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) |
1089 | { |
1090 | return 0; |
1091 | } |
1092 | static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr) |
1093 | { |
1094 | return 0; |
1095 | } |
1096 | static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) |
1097 | { |
1098 | return 0; |
1099 | } |
1100 | #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ |
1101 | |
1102 | #ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE |
1103 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
1104 | /* |
1105 | * ARCHes with special requirements for evicting THP backing TLB entries can |
1106 | * implement this. Otherwise also, it can help optimize normal TLB flush in |
1107 | * THP regime. stock flush_tlb_range() typically has optimization to nuke the |
1108 | * entire TLB TLB if flush span is greater than a threshold, which will |
1109 | * likely be true for a single huge page. Thus a single thp flush will |
1110 | * invalidate the entire TLB which is not desitable. |
1111 | * e.g. see arch/arc: flush_pmd_tlb_range |
1112 | */ |
1113 | #define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) |
1114 | #define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) |
1115 | #else |
1116 | #define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG() |
1117 | #define flush_pud_tlb_range(vma, addr, end) BUILD_BUG() |
1118 | #endif |
1119 | #endif |
1120 | |
1121 | struct file; |
1122 | int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, |
1123 | unsigned long size, pgprot_t *vma_prot); |
1124 | |
1125 | #ifndef CONFIG_X86_ESPFIX64 |
1126 | static inline void init_espfix_bsp(void) { } |
1127 | #endif |
1128 | |
1129 | #ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED |
1130 | static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot) |
1131 | { |
1132 | return true; |
1133 | } |
1134 | |
1135 | static inline bool arch_has_pfn_modify_check(void) |
1136 | { |
1137 | return false; |
1138 | } |
1139 | #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */ |
1140 | |
1141 | /* |
1142 | * Architecture PAGE_KERNEL_* fallbacks |
1143 | * |
1144 | * Some architectures don't define certain PAGE_KERNEL_* flags. This is either |
1145 | * because they really don't support them, or the port needs to be updated to |
1146 | * reflect the required functionality. Below are a set of relatively safe |
1147 | * fallbacks, as best effort, which we can count on in lieu of the architectures |
1148 | * not defining them on their own yet. |
1149 | */ |
1150 | |
1151 | #ifndef PAGE_KERNEL_RO |
1152 | # define PAGE_KERNEL_RO PAGE_KERNEL |
1153 | #endif |
1154 | |
1155 | #ifndef PAGE_KERNEL_EXEC |
1156 | # define PAGE_KERNEL_EXEC PAGE_KERNEL |
1157 | #endif |
1158 | |
1159 | #endif /* !__ASSEMBLY__ */ |
1160 | |
1161 | #ifndef io_remap_pfn_range |
1162 | #define io_remap_pfn_range remap_pfn_range |
1163 | #endif |
1164 | |
1165 | #ifndef has_transparent_hugepage |
1166 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
1167 | #define has_transparent_hugepage() 1 |
1168 | #else |
1169 | #define has_transparent_hugepage() 0 |
1170 | #endif |
1171 | #endif |
1172 | |
1173 | /* |
1174 | * On some architectures it depends on the mm if the p4d/pud or pmd |
1175 | * layer of the page table hierarchy is folded or not. |
1176 | */ |
1177 | #ifndef mm_p4d_folded |
1178 | #define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED) |
1179 | #endif |
1180 | |
1181 | #ifndef mm_pud_folded |
1182 | #define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED) |
1183 | #endif |
1184 | |
1185 | #ifndef mm_pmd_folded |
1186 | #define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED) |
1187 | #endif |
1188 | |
1189 | #endif /* _ASM_GENERIC_PGTABLE_H */ |
1190 | |