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
pmdp_set_access_flags(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp,pmd_t entry,int dirty)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 }
pudp_set_access_flags(struct vm_area_struct * vma,unsigned long address,pud_t * pudp,pud_t entry,int dirty)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
ptep_test_and_clear_young(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)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
pmdp_test_and_clear_young(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)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
pmdp_test_and_clear_young(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)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 */
pmdp_clear_flush_young(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)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
ptep_get_and_clear(struct mm_struct * mm,unsigned long address,pte_t * ptep)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
pmdp_huge_get_and_clear(struct mm_struct * mm,unsigned long address,pmd_t * pmdp)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
pudp_huge_get_and_clear(struct mm_struct * mm,unsigned long address,pud_t * pudp)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
pmdp_huge_get_and_clear_full(struct mm_struct * mm,unsigned long address,pmd_t * pmdp,int 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
pudp_huge_get_and_clear_full(struct mm_struct * mm,unsigned long address,pud_t * pudp,int 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
ptep_get_and_clear_full(struct mm_struct * mm,unsigned long address,pte_t * ptep,int 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
pte_clear_not_present_full(struct mm_struct * mm,unsigned long address,pte_t * ptep,int 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;
ptep_set_wrprotect(struct mm_struct * mm,unsigned long address,pte_t * ptep)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
pmdp_set_wrprotect(struct mm_struct * mm,unsigned long address,pmd_t * pmdp)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
pmdp_set_wrprotect(struct mm_struct * mm,unsigned long address,pmd_t * pmdp)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
pudp_set_wrprotect(struct mm_struct * mm,unsigned long address,pud_t * pudp)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
pudp_set_wrprotect(struct mm_struct * mm,unsigned long address,pud_t * pudp)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
pmdp_collapse_flush(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)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 */
generic_pmdp_establish(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp,pmd_t pmd)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
pte_same(pte_t pte_a,pte_t pte_b)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 */
pte_unused(pte_t pte)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 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_same(pmd_t pmd_a,pmd_t pmd_b)379 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
380 {
381 return pmd_val(pmd_a) == pmd_val(pmd_b);
382 }
383
pud_same(pud_t pud_a,pud_t pud_b)384 static inline int pud_same(pud_t pud_a, pud_t pud_b)
385 {
386 return pud_val(pud_a) == pud_val(pud_b);
387 }
388 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
pmd_same(pmd_t pmd_a,pmd_t pmd_b)389 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
390 {
391 BUILD_BUG();
392 return 0;
393 }
394
pud_same(pud_t pud_a,pud_t pud_b)395 static inline int pud_same(pud_t pud_a, pud_t pud_b)
396 {
397 BUILD_BUG();
398 return 0;
399 }
400 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
401 #endif
402
403 #ifndef __HAVE_ARCH_DO_SWAP_PAGE
404 /*
405 * Some architectures support metadata associated with a page. When a
406 * page is being swapped out, this metadata must be saved so it can be
407 * restored when the page is swapped back in. SPARC M7 and newer
408 * processors support an ADI (Application Data Integrity) tag for the
409 * page as metadata for the page. arch_do_swap_page() can restore this
410 * metadata when a page is swapped back in.
411 */
arch_do_swap_page(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long addr,pte_t pte,pte_t oldpte)412 static inline void arch_do_swap_page(struct mm_struct *mm,
413 struct vm_area_struct *vma,
414 unsigned long addr,
415 pte_t pte, pte_t oldpte)
416 {
417
418 }
419 #endif
420
421 #ifndef __HAVE_ARCH_UNMAP_ONE
422 /*
423 * Some architectures support metadata associated with a page. When a
424 * page is being swapped out, this metadata must be saved so it can be
425 * restored when the page is swapped back in. SPARC M7 and newer
426 * processors support an ADI (Application Data Integrity) tag for the
427 * page as metadata for the page. arch_unmap_one() can save this
428 * metadata on a swap-out of a page.
429 */
arch_unmap_one(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long addr,pte_t orig_pte)430 static inline int arch_unmap_one(struct mm_struct *mm,
431 struct vm_area_struct *vma,
432 unsigned long addr,
433 pte_t orig_pte)
434 {
435 return 0;
436 }
437 #endif
438
439 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
440 #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
441 #endif
442
443 #ifndef __HAVE_ARCH_MOVE_PTE
444 #define move_pte(pte, prot, old_addr, new_addr) (pte)
445 #endif
446
447 #ifndef pte_accessible
448 # define pte_accessible(mm, pte) ((void)(pte), 1)
449 #endif
450
451 #ifndef flush_tlb_fix_spurious_fault
452 #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
453 #endif
454
455 #ifndef pgprot_noncached
456 #define pgprot_noncached(prot) (prot)
457 #endif
458
459 #ifndef pgprot_writecombine
460 #define pgprot_writecombine pgprot_noncached
461 #endif
462
463 #ifndef pgprot_writethrough
464 #define pgprot_writethrough pgprot_noncached
465 #endif
466
467 #ifndef pgprot_device
468 #define pgprot_device pgprot_noncached
469 #endif
470
471 #ifndef pgprot_modify
472 #define pgprot_modify pgprot_modify
pgprot_modify(pgprot_t oldprot,pgprot_t newprot)473 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
474 {
475 if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
476 newprot = pgprot_noncached(newprot);
477 if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
478 newprot = pgprot_writecombine(newprot);
479 if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
480 newprot = pgprot_device(newprot);
481 return newprot;
482 }
483 #endif
484
485 /*
486 * When walking page tables, get the address of the next boundary,
487 * or the end address of the range if that comes earlier. Although no
488 * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
489 */
490
491 #define pgd_addr_end(addr, end) \
492 ({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
493 (__boundary - 1 < (end) - 1)? __boundary: (end); \
494 })
495
496 #ifndef p4d_addr_end
497 #define p4d_addr_end(addr, end) \
498 ({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
499 (__boundary - 1 < (end) - 1)? __boundary: (end); \
500 })
501 #endif
502
503 #ifndef pud_addr_end
504 #define pud_addr_end(addr, end) \
505 ({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
506 (__boundary - 1 < (end) - 1)? __boundary: (end); \
507 })
508 #endif
509
510 #ifndef pmd_addr_end
511 #define pmd_addr_end(addr, end) \
512 ({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
513 (__boundary - 1 < (end) - 1)? __boundary: (end); \
514 })
515 #endif
516
517 /*
518 * When walking page tables, we usually want to skip any p?d_none entries;
519 * and any p?d_bad entries - reporting the error before resetting to none.
520 * Do the tests inline, but report and clear the bad entry in mm/memory.c.
521 */
522 void pgd_clear_bad(pgd_t *);
523 void p4d_clear_bad(p4d_t *);
524 void pud_clear_bad(pud_t *);
525 void pmd_clear_bad(pmd_t *);
526
pgd_none_or_clear_bad(pgd_t * pgd)527 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
528 {
529 if (pgd_none(*pgd))
530 return 1;
531 if (unlikely(pgd_bad(*pgd))) {
532 pgd_clear_bad(pgd);
533 return 1;
534 }
535 return 0;
536 }
537
p4d_none_or_clear_bad(p4d_t * p4d)538 static inline int p4d_none_or_clear_bad(p4d_t *p4d)
539 {
540 if (p4d_none(*p4d))
541 return 1;
542 if (unlikely(p4d_bad(*p4d))) {
543 p4d_clear_bad(p4d);
544 return 1;
545 }
546 return 0;
547 }
548
pud_none_or_clear_bad(pud_t * pud)549 static inline int pud_none_or_clear_bad(pud_t *pud)
550 {
551 if (pud_none(*pud))
552 return 1;
553 if (unlikely(pud_bad(*pud))) {
554 pud_clear_bad(pud);
555 return 1;
556 }
557 return 0;
558 }
559
pmd_none_or_clear_bad(pmd_t * pmd)560 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
561 {
562 if (pmd_none(*pmd))
563 return 1;
564 if (unlikely(pmd_bad(*pmd))) {
565 pmd_clear_bad(pmd);
566 return 1;
567 }
568 return 0;
569 }
570
__ptep_modify_prot_start(struct mm_struct * mm,unsigned long addr,pte_t * ptep)571 static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
572 unsigned long addr,
573 pte_t *ptep)
574 {
575 /*
576 * Get the current pte state, but zero it out to make it
577 * non-present, preventing the hardware from asynchronously
578 * updating it.
579 */
580 return ptep_get_and_clear(mm, addr, ptep);
581 }
582
__ptep_modify_prot_commit(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte)583 static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
584 unsigned long addr,
585 pte_t *ptep, pte_t pte)
586 {
587 /*
588 * The pte is non-present, so there's no hardware state to
589 * preserve.
590 */
591 set_pte_at(mm, addr, ptep, pte);
592 }
593
594 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
595 /*
596 * Start a pte protection read-modify-write transaction, which
597 * protects against asynchronous hardware modifications to the pte.
598 * The intention is not to prevent the hardware from making pte
599 * updates, but to prevent any updates it may make from being lost.
600 *
601 * This does not protect against other software modifications of the
602 * pte; the appropriate pte lock must be held over the transation.
603 *
604 * Note that this interface is intended to be batchable, meaning that
605 * ptep_modify_prot_commit may not actually update the pte, but merely
606 * queue the update to be done at some later time. The update must be
607 * actually committed before the pte lock is released, however.
608 */
ptep_modify_prot_start(struct mm_struct * mm,unsigned long addr,pte_t * ptep)609 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
610 unsigned long addr,
611 pte_t *ptep)
612 {
613 return __ptep_modify_prot_start(mm, addr, ptep);
614 }
615
616 /*
617 * Commit an update to a pte, leaving any hardware-controlled bits in
618 * the PTE unmodified.
619 */
ptep_modify_prot_commit(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte)620 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
621 unsigned long addr,
622 pte_t *ptep, pte_t pte)
623 {
624 __ptep_modify_prot_commit(mm, addr, ptep, pte);
625 }
626 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
627 #endif /* CONFIG_MMU */
628
629 /*
630 * No-op macros that just return the current protection value. Defined here
631 * because these macros can be used used even if CONFIG_MMU is not defined.
632 */
633 #ifndef pgprot_encrypted
634 #define pgprot_encrypted(prot) (prot)
635 #endif
636
637 #ifndef pgprot_decrypted
638 #define pgprot_decrypted(prot) (prot)
639 #endif
640
641 /*
642 * A facility to provide lazy MMU batching. This allows PTE updates and
643 * page invalidations to be delayed until a call to leave lazy MMU mode
644 * is issued. Some architectures may benefit from doing this, and it is
645 * beneficial for both shadow and direct mode hypervisors, which may batch
646 * the PTE updates which happen during this window. Note that using this
647 * interface requires that read hazards be removed from the code. A read
648 * hazard could result in the direct mode hypervisor case, since the actual
649 * write to the page tables may not yet have taken place, so reads though
650 * a raw PTE pointer after it has been modified are not guaranteed to be
651 * up to date. This mode can only be entered and left under the protection of
652 * the page table locks for all page tables which may be modified. In the UP
653 * case, this is required so that preemption is disabled, and in the SMP case,
654 * it must synchronize the delayed page table writes properly on other CPUs.
655 */
656 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
657 #define arch_enter_lazy_mmu_mode() do {} while (0)
658 #define arch_leave_lazy_mmu_mode() do {} while (0)
659 #define arch_flush_lazy_mmu_mode() do {} while (0)
660 #endif
661
662 /*
663 * A facility to provide batching of the reload of page tables and
664 * other process state with the actual context switch code for
665 * paravirtualized guests. By convention, only one of the batched
666 * update (lazy) modes (CPU, MMU) should be active at any given time,
667 * entry should never be nested, and entry and exits should always be
668 * paired. This is for sanity of maintaining and reasoning about the
669 * kernel code. In this case, the exit (end of the context switch) is
670 * in architecture-specific code, and so doesn't need a generic
671 * definition.
672 */
673 #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
674 #define arch_start_context_switch(prev) do {} while (0)
675 #endif
676
677 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
678 #ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
pmd_swp_mksoft_dirty(pmd_t pmd)679 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
680 {
681 return pmd;
682 }
683
pmd_swp_soft_dirty(pmd_t pmd)684 static inline int pmd_swp_soft_dirty(pmd_t pmd)
685 {
686 return 0;
687 }
688
pmd_swp_clear_soft_dirty(pmd_t pmd)689 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
690 {
691 return pmd;
692 }
693 #endif
694 #else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
pte_soft_dirty(pte_t pte)695 static inline int pte_soft_dirty(pte_t pte)
696 {
697 return 0;
698 }
699
pmd_soft_dirty(pmd_t pmd)700 static inline int pmd_soft_dirty(pmd_t pmd)
701 {
702 return 0;
703 }
704
pte_mksoft_dirty(pte_t pte)705 static inline pte_t pte_mksoft_dirty(pte_t pte)
706 {
707 return pte;
708 }
709
pmd_mksoft_dirty(pmd_t pmd)710 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
711 {
712 return pmd;
713 }
714
pte_clear_soft_dirty(pte_t pte)715 static inline pte_t pte_clear_soft_dirty(pte_t pte)
716 {
717 return pte;
718 }
719
pmd_clear_soft_dirty(pmd_t pmd)720 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
721 {
722 return pmd;
723 }
724
pte_swp_mksoft_dirty(pte_t pte)725 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
726 {
727 return pte;
728 }
729
pte_swp_soft_dirty(pte_t pte)730 static inline int pte_swp_soft_dirty(pte_t pte)
731 {
732 return 0;
733 }
734
pte_swp_clear_soft_dirty(pte_t pte)735 static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
736 {
737 return pte;
738 }
739
pmd_swp_mksoft_dirty(pmd_t pmd)740 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
741 {
742 return pmd;
743 }
744
pmd_swp_soft_dirty(pmd_t pmd)745 static inline int pmd_swp_soft_dirty(pmd_t pmd)
746 {
747 return 0;
748 }
749
pmd_swp_clear_soft_dirty(pmd_t pmd)750 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
751 {
752 return pmd;
753 }
754 #endif
755
756 #ifndef __HAVE_PFNMAP_TRACKING
757 /*
758 * Interfaces that can be used by architecture code to keep track of
759 * memory type of pfn mappings specified by the remap_pfn_range,
760 * vm_insert_pfn.
761 */
762
763 /*
764 * track_pfn_remap is called when a _new_ pfn mapping is being established
765 * by remap_pfn_range() for physical range indicated by pfn and size.
766 */
track_pfn_remap(struct vm_area_struct * vma,pgprot_t * prot,unsigned long pfn,unsigned long addr,unsigned long size)767 static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
768 unsigned long pfn, unsigned long addr,
769 unsigned long size)
770 {
771 return 0;
772 }
773
774 /*
775 * track_pfn_insert is called when a _new_ single pfn is established
776 * by vm_insert_pfn().
777 */
track_pfn_insert(struct vm_area_struct * vma,pgprot_t * prot,pfn_t pfn)778 static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
779 pfn_t pfn)
780 {
781 }
782
783 /*
784 * track_pfn_copy is called when vma that is covering the pfnmap gets
785 * copied through copy_page_range().
786 */
track_pfn_copy(struct vm_area_struct * vma)787 static inline int track_pfn_copy(struct vm_area_struct *vma)
788 {
789 return 0;
790 }
791
792 /*
793 * untrack_pfn is called while unmapping a pfnmap for a region.
794 * untrack can be called for a specific region indicated by pfn and size or
795 * can be for the entire vma (in which case pfn, size are zero).
796 */
untrack_pfn(struct vm_area_struct * vma,unsigned long pfn,unsigned long size)797 static inline void untrack_pfn(struct vm_area_struct *vma,
798 unsigned long pfn, unsigned long size)
799 {
800 }
801
802 /*
803 * untrack_pfn_moved is called while mremapping a pfnmap for a new region.
804 */
untrack_pfn_moved(struct vm_area_struct * vma)805 static inline void untrack_pfn_moved(struct vm_area_struct *vma)
806 {
807 }
808 #else
809 extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
810 unsigned long pfn, unsigned long addr,
811 unsigned long size);
812 extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
813 pfn_t pfn);
814 extern int track_pfn_copy(struct vm_area_struct *vma);
815 extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
816 unsigned long size);
817 extern void untrack_pfn_moved(struct vm_area_struct *vma);
818 #endif
819
820 #ifdef __HAVE_COLOR_ZERO_PAGE
is_zero_pfn(unsigned long pfn)821 static inline int is_zero_pfn(unsigned long pfn)
822 {
823 extern unsigned long zero_pfn;
824 unsigned long offset_from_zero_pfn = pfn - zero_pfn;
825 return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
826 }
827
828 #define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
829
830 #else
is_zero_pfn(unsigned long pfn)831 static inline int is_zero_pfn(unsigned long pfn)
832 {
833 extern unsigned long zero_pfn;
834 return pfn == zero_pfn;
835 }
836
my_zero_pfn(unsigned long addr)837 static inline unsigned long my_zero_pfn(unsigned long addr)
838 {
839 extern unsigned long zero_pfn;
840 return zero_pfn;
841 }
842 #endif
843
844 #ifdef CONFIG_MMU
845
846 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
pmd_trans_huge(pmd_t pmd)847 static inline int pmd_trans_huge(pmd_t pmd)
848 {
849 return 0;
850 }
851 #ifndef pmd_write
pmd_write(pmd_t pmd)852 static inline int pmd_write(pmd_t pmd)
853 {
854 BUG();
855 return 0;
856 }
857 #endif /* pmd_write */
858 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
859
860 #ifndef pud_write
pud_write(pud_t pud)861 static inline int pud_write(pud_t pud)
862 {
863 BUG();
864 return 0;
865 }
866 #endif /* pud_write */
867
868 #if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
869 (defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
870 !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
pud_trans_huge(pud_t pud)871 static inline int pud_trans_huge(pud_t pud)
872 {
873 return 0;
874 }
875 #endif
876
877 #ifndef pmd_read_atomic
pmd_read_atomic(pmd_t * pmdp)878 static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
879 {
880 /*
881 * Depend on compiler for an atomic pmd read. NOTE: this is
882 * only going to work, if the pmdval_t isn't larger than
883 * an unsigned long.
884 */
885 return *pmdp;
886 }
887 #endif
888
889 #ifndef arch_needs_pgtable_deposit
890 #define arch_needs_pgtable_deposit() (false)
891 #endif
892 /*
893 * This function is meant to be used by sites walking pagetables with
894 * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
895 * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
896 * into a null pmd and the transhuge page fault can convert a null pmd
897 * into an hugepmd or into a regular pmd (if the hugepage allocation
898 * fails). While holding the mmap_sem in read mode the pmd becomes
899 * stable and stops changing under us only if it's not null and not a
900 * transhuge pmd. When those races occurs and this function makes a
901 * difference vs the standard pmd_none_or_clear_bad, the result is
902 * undefined so behaving like if the pmd was none is safe (because it
903 * can return none anyway). The compiler level barrier() is critically
904 * important to compute the two checks atomically on the same pmdval.
905 *
906 * For 32bit kernels with a 64bit large pmd_t this automatically takes
907 * care of reading the pmd atomically to avoid SMP race conditions
908 * against pmd_populate() when the mmap_sem is hold for reading by the
909 * caller (a special atomic read not done by "gcc" as in the generic
910 * version above, is also needed when THP is disabled because the page
911 * fault can populate the pmd from under us).
912 */
pmd_none_or_trans_huge_or_clear_bad(pmd_t * pmd)913 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
914 {
915 pmd_t pmdval = pmd_read_atomic(pmd);
916 /*
917 * The barrier will stabilize the pmdval in a register or on
918 * the stack so that it will stop changing under the code.
919 *
920 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
921 * pmd_read_atomic is allowed to return a not atomic pmdval
922 * (for example pointing to an hugepage that has never been
923 * mapped in the pmd). The below checks will only care about
924 * the low part of the pmd with 32bit PAE x86 anyway, with the
925 * exception of pmd_none(). So the important thing is that if
926 * the low part of the pmd is found null, the high part will
927 * be also null or the pmd_none() check below would be
928 * confused.
929 */
930 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
931 barrier();
932 #endif
933 /*
934 * !pmd_present() checks for pmd migration entries
935 *
936 * The complete check uses is_pmd_migration_entry() in linux/swapops.h
937 * But using that requires moving current function and pmd_trans_unstable()
938 * to linux/swapops.h to resovle dependency, which is too much code move.
939 *
940 * !pmd_present() is equivalent to is_pmd_migration_entry() currently,
941 * because !pmd_present() pages can only be under migration not swapped
942 * out.
943 *
944 * pmd_none() is preseved for future condition checks on pmd migration
945 * entries and not confusing with this function name, although it is
946 * redundant with !pmd_present().
947 */
948 if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
949 (IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
950 return 1;
951 if (unlikely(pmd_bad(pmdval))) {
952 pmd_clear_bad(pmd);
953 return 1;
954 }
955 return 0;
956 }
957
958 /*
959 * This is a noop if Transparent Hugepage Support is not built into
960 * the kernel. Otherwise it is equivalent to
961 * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
962 * places that already verified the pmd is not none and they want to
963 * walk ptes while holding the mmap sem in read mode (write mode don't
964 * need this). If THP is not enabled, the pmd can't go away under the
965 * code even if MADV_DONTNEED runs, but if THP is enabled we need to
966 * run a pmd_trans_unstable before walking the ptes after
967 * split_huge_page_pmd returns (because it may have run when the pmd
968 * become null, but then a page fault can map in a THP and not a
969 * regular page).
970 */
pmd_trans_unstable(pmd_t * pmd)971 static inline int pmd_trans_unstable(pmd_t *pmd)
972 {
973 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
974 return pmd_none_or_trans_huge_or_clear_bad(pmd);
975 #else
976 return 0;
977 #endif
978 }
979
980 #ifndef CONFIG_NUMA_BALANCING
981 /*
982 * Technically a PTE can be PROTNONE even when not doing NUMA balancing but
983 * the only case the kernel cares is for NUMA balancing and is only ever set
984 * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
985 * _PAGE_PROTNONE so by by default, implement the helper as "always no". It
986 * is the responsibility of the caller to distinguish between PROT_NONE
987 * protections and NUMA hinting fault protections.
988 */
pte_protnone(pte_t pte)989 static inline int pte_protnone(pte_t pte)
990 {
991 return 0;
992 }
993
pmd_protnone(pmd_t pmd)994 static inline int pmd_protnone(pmd_t pmd)
995 {
996 return 0;
997 }
998 #endif /* CONFIG_NUMA_BALANCING */
999
1000 #endif /* CONFIG_MMU */
1001
1002 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
1003
1004 #ifndef __PAGETABLE_P4D_FOLDED
1005 int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
1006 int p4d_clear_huge(p4d_t *p4d);
1007 #else
p4d_set_huge(p4d_t * p4d,phys_addr_t addr,pgprot_t prot)1008 static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
1009 {
1010 return 0;
1011 }
p4d_clear_huge(p4d_t * p4d)1012 static inline int p4d_clear_huge(p4d_t *p4d)
1013 {
1014 return 0;
1015 }
1016 #endif /* !__PAGETABLE_P4D_FOLDED */
1017
1018 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
1019 int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
1020 int pud_clear_huge(pud_t *pud);
1021 int pmd_clear_huge(pmd_t *pmd);
1022 int pud_free_pmd_page(pud_t *pud, unsigned long addr);
1023 int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
1024 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
p4d_set_huge(p4d_t * p4d,phys_addr_t addr,pgprot_t prot)1025 static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
1026 {
1027 return 0;
1028 }
pud_set_huge(pud_t * pud,phys_addr_t addr,pgprot_t prot)1029 static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
1030 {
1031 return 0;
1032 }
pmd_set_huge(pmd_t * pmd,phys_addr_t addr,pgprot_t prot)1033 static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
1034 {
1035 return 0;
1036 }
p4d_clear_huge(p4d_t * p4d)1037 static inline int p4d_clear_huge(p4d_t *p4d)
1038 {
1039 return 0;
1040 }
pud_clear_huge(pud_t * pud)1041 static inline int pud_clear_huge(pud_t *pud)
1042 {
1043 return 0;
1044 }
pmd_clear_huge(pmd_t * pmd)1045 static inline int pmd_clear_huge(pmd_t *pmd)
1046 {
1047 return 0;
1048 }
pud_free_pmd_page(pud_t * pud,unsigned long addr)1049 static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
1050 {
1051 return 0;
1052 }
pmd_free_pte_page(pmd_t * pmd,unsigned long addr)1053 static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
1054 {
1055 return 0;
1056 }
1057 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
1058
1059 #ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
1060 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1061 /*
1062 * ARCHes with special requirements for evicting THP backing TLB entries can
1063 * implement this. Otherwise also, it can help optimize normal TLB flush in
1064 * THP regime. stock flush_tlb_range() typically has optimization to nuke the
1065 * entire TLB TLB if flush span is greater than a threshold, which will
1066 * likely be true for a single huge page. Thus a single thp flush will
1067 * invalidate the entire TLB which is not desitable.
1068 * e.g. see arch/arc: flush_pmd_tlb_range
1069 */
1070 #define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
1071 #define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
1072 #else
1073 #define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG()
1074 #define flush_pud_tlb_range(vma, addr, end) BUILD_BUG()
1075 #endif
1076 #endif
1077
1078 struct file;
1079 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
1080 unsigned long size, pgprot_t *vma_prot);
1081
1082 #ifndef CONFIG_X86_ESPFIX64
init_espfix_bsp(void)1083 static inline void init_espfix_bsp(void) { }
1084 #endif
1085
1086 #ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
pfn_modify_allowed(unsigned long pfn,pgprot_t prot)1087 static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
1088 {
1089 return true;
1090 }
1091
arch_has_pfn_modify_check(void)1092 static inline bool arch_has_pfn_modify_check(void)
1093 {
1094 return false;
1095 }
1096 #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
1097
1098 /*
1099 * Architecture PAGE_KERNEL_* fallbacks
1100 *
1101 * Some architectures don't define certain PAGE_KERNEL_* flags. This is either
1102 * because they really don't support them, or the port needs to be updated to
1103 * reflect the required functionality. Below are a set of relatively safe
1104 * fallbacks, as best effort, which we can count on in lieu of the architectures
1105 * not defining them on their own yet.
1106 */
1107
1108 #ifndef PAGE_KERNEL_RO
1109 # define PAGE_KERNEL_RO PAGE_KERNEL
1110 #endif
1111
1112 #ifndef PAGE_KERNEL_EXEC
1113 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1114 #endif
1115
1116 #endif /* !__ASSEMBLY__ */
1117
1118 #if !defined(MAX_POSSIBLE_PHYSMEM_BITS) && !defined(CONFIG_64BIT)
1119 #ifdef CONFIG_PHYS_ADDR_T_64BIT
1120 /*
1121 * ZSMALLOC needs to know the highest PFN on 32-bit architectures
1122 * with physical address space extension, but falls back to
1123 * BITS_PER_LONG otherwise.
1124 */
1125 #error Missing MAX_POSSIBLE_PHYSMEM_BITS definition
1126 #else
1127 #define MAX_POSSIBLE_PHYSMEM_BITS 32
1128 #endif
1129 #endif
1130
1131 #ifndef has_transparent_hugepage
1132 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1133 #define has_transparent_hugepage() 1
1134 #else
1135 #define has_transparent_hugepage() 0
1136 #endif
1137 #endif
1138
1139 /*
1140 * On some architectures it depends on the mm if the p4d/pud or pmd
1141 * layer of the page table hierarchy is folded or not.
1142 */
1143 #ifndef mm_p4d_folded
1144 #define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED)
1145 #endif
1146
1147 #ifndef mm_pud_folded
1148 #define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED)
1149 #endif
1150
1151 #ifndef mm_pmd_folded
1152 #define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
1153 #endif
1154
1155 #endif /* _ASM_GENERIC_PGTABLE_H */
1156