projects/linux·blob v5.8-rc4 · refs

1445 lines · 38.9 KiB

1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_PGTABLE_H
3#define _LINUX_PGTABLE_H
4
5#include <linux/pfn.h>
6#include <asm/pgtable.h>
7
8#ifndef __ASSEMBLY__
9#ifdef CONFIG_MMU
10
11#include <linux/mm_types.h>
12#include <linux/bug.h>
13#include <linux/errno.h>
14#include <asm-generic/pgtable_uffd.h>
15
16#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
17 defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
18#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
19#endif
20
21/*
22 * On almost all architectures and configurations, 0 can be used as the
23 * upper ceiling to free_pgtables(): on many architectures it has the same
24 * effect as using TASK_SIZE. However, there is one configuration which
25 * must impose a more careful limit, to avoid freeing kernel pgtables.
26 */
27#ifndef USER_PGTABLES_CEILING
28#define USER_PGTABLES_CEILING 0UL
29#endif
30
31/*
32 * A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
33 *
34 * The pXx_index() functions return the index of the entry in the page
35 * table page which would control the given virtual address
36 *
37 * As these functions may be used by the same code for different levels of
38 * the page table folding, they are always available, regardless of
39 * CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
40 * because in such cases PTRS_PER_PxD equals 1.
41 */
42
43static inline unsigned long pte_index(unsigned long address)
44{
45 return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
46}
47
48#ifndef pmd_index
49static inline unsigned long pmd_index(unsigned long address)
50{
51 return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
52}
53#define pmd_index pmd_index
54#endif
55
56#ifndef pud_index
57static inline unsigned long pud_index(unsigned long address)
58{
59 return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
60}
61#define pud_index pud_index
62#endif
63
64#ifndef pgd_index
65/* Must be a compile-time constant, so implement it as a macro */
66#define pgd_index(a) (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
67#endif
68
69#ifndef pte_offset_kernel
70static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
71{
72 return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
73}
74#define pte_offset_kernel pte_offset_kernel
75#endif
76
77#if defined(CONFIG_HIGHPTE)
78#define pte_offset_map(dir, address) \
79 ((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
80 pte_index((address)))
81#define pte_unmap(pte) kunmap_atomic((pte))
82#else
83#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
84#define pte_unmap(pte) ((void)(pte)) /* NOP */
85#endif
86
87/* Find an entry in the second-level page table.. */
88#ifndef pmd_offset
89static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
90{
91 return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
92}
93#define pmd_offset pmd_offset
94#endif
95
96#ifndef pud_offset
97static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
98{
99 return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
100}
101#define pud_offset pud_offset
102#endif
103
104static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
105{
106 return (pgd + pgd_index(address));
107};
108
109/*
110 * a shortcut to get a pgd_t in a given mm
111 */
112#ifndef pgd_offset
113#define pgd_offset(mm, address) pgd_offset_pgd((mm)->pgd, (address))
114#endif
115
116/*
117 * a shortcut which implies the use of the kernel's pgd, instead
118 * of a process's
119 */
120#define pgd_offset_k(address) pgd_offset(&init_mm, (address))
121
122/*
123 * In many cases it is known that a virtual address is mapped at PMD or PTE
124 * level, so instead of traversing all the page table levels, we can get a
125 * pointer to the PMD entry in user or kernel page table or translate a virtual
126 * address to the pointer in the PTE in the kernel page tables with simple
127 * helpers.
128 */
129static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
130{
131 return pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, va), va), va), va);
132}
133
134static inline pmd_t *pmd_off_k(unsigned long va)
135{
136 return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
137}
138
139static inline pte_t *virt_to_kpte(unsigned long vaddr)
140{
141 pmd_t *pmd = pmd_off_k(vaddr);
142
143 return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr);
144}
145
146#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
147extern int ptep_set_access_flags(struct vm_area_struct *vma,
148 unsigned long address, pte_t *ptep,
149 pte_t entry, int dirty);
150#endif
151
152#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
153#ifdef CONFIG_TRANSPARENT_HUGEPAGE
154extern int pmdp_set_access_flags(struct vm_area_struct *vma,
155 unsigned long address, pmd_t *pmdp,
156 pmd_t entry, int dirty);
157extern int pudp_set_access_flags(struct vm_area_struct *vma,
158 unsigned long address, pud_t *pudp,
159 pud_t entry, int dirty);
160#else
161static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
162 unsigned long address, pmd_t *pmdp,
163 pmd_t entry, int dirty)
164{
165 BUILD_BUG();
166 return 0;
167}
168static inline int pudp_set_access_flags(struct vm_area_struct *vma,
169 unsigned long address, pud_t *pudp,
170 pud_t entry, int dirty)
171{
172 BUILD_BUG();
173 return 0;
174}
175#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
176#endif
177
178#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
179static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
180 unsigned long address,
181 pte_t *ptep)
182{
183 pte_t pte = *ptep;
184 int r = 1;
185 if (!pte_young(pte))
186 r = 0;
187 else
188 set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
189 return r;
190}
191#endif
192
193#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
194#ifdef CONFIG_TRANSPARENT_HUGEPAGE
195static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
196 unsigned long address,
197 pmd_t *pmdp)
198{
199 pmd_t pmd = *pmdp;
200 int r = 1;
201 if (!pmd_young(pmd))
202 r = 0;
203 else
204 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
205 return r;
206}
207#else
208static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
209 unsigned long address,
210 pmd_t *pmdp)
211{
212 BUILD_BUG();
213 return 0;
214}
215#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
216#endif
217
218#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
219int ptep_clear_flush_young(struct vm_area_struct *vma,
220 unsigned long address, pte_t *ptep);
221#endif
222
223#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
224#ifdef CONFIG_TRANSPARENT_HUGEPAGE
225extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
226 unsigned long address, pmd_t *pmdp);
227#else
228/*
229 * Despite relevant to THP only, this API is called from generic rmap code
230 * under PageTransHuge(), hence needs a dummy implementation for !THP
231 */
232static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
233 unsigned long address, pmd_t *pmdp)
234{
235 BUILD_BUG();
236 return 0;
237}
238#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
239#endif
240
241#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
242static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
243 unsigned long address,
244 pte_t *ptep)
245{
246 pte_t pte = *ptep;
247 pte_clear(mm, address, ptep);
248 return pte;
249}
250#endif
251
252#ifndef __HAVE_ARCH_PTEP_GET
253static inline pte_t ptep_get(pte_t *ptep)
254{
255 return READ_ONCE(*ptep);
256}
257#endif
258
259#ifdef CONFIG_TRANSPARENT_HUGEPAGE
260#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
261static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
262 unsigned long address,
263 pmd_t *pmdp)
264{
265 pmd_t pmd = *pmdp;
266 pmd_clear(pmdp);
267 return pmd;
268}
269#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
270#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
271static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
272 unsigned long address,
273 pud_t *pudp)
274{
275 pud_t pud = *pudp;
276
277 pud_clear(pudp);
278 return pud;
279}
280#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
281#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
282
283#ifdef CONFIG_TRANSPARENT_HUGEPAGE
284#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
285static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
286 unsigned long address, pmd_t *pmdp,
287 int full)
288{
289 return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
290}
291#endif
292
293#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
294static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
295 unsigned long address, pud_t *pudp,
296 int full)
297{
298 return pudp_huge_get_and_clear(mm, address, pudp);
299}
300#endif
301#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
302
303#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
304static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
305 unsigned long address, pte_t *ptep,
306 int full)
307{
308 pte_t pte;
309 pte = ptep_get_and_clear(mm, address, ptep);
310 return pte;
311}
312#endif
313
314
315/*
316 * If two threads concurrently fault at the same page, the thread that
317 * won the race updates the PTE and its local TLB/Cache. The other thread
318 * gives up, simply does nothing, and continues; on architectures where
319 * software can update TLB, local TLB can be updated here to avoid next page
320 * fault. This function updates TLB only, do nothing with cache or others.
321 * It is the difference with function update_mmu_cache.
322 */
323#ifndef __HAVE_ARCH_UPDATE_MMU_TLB
324static inline void update_mmu_tlb(struct vm_area_struct *vma,
325 unsigned long address, pte_t *ptep)
326{
327}
328#define __HAVE_ARCH_UPDATE_MMU_TLB
329#endif
330
331/*
332 * Some architectures may be able to avoid expensive synchronization
333 * primitives when modifications are made to PTE's which are already
334 * not present, or in the process of an address space destruction.
335 */
336#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
337static inline void pte_clear_not_present_full(struct mm_struct *mm,
338 unsigned long address,
339 pte_t *ptep,
340 int full)
341{
342 pte_clear(mm, address, ptep);
343}
344#endif
345
346#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
347extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
348 unsigned long address,
349 pte_t *ptep);
350#endif
351
352#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
353extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
354 unsigned long address,
355 pmd_t *pmdp);
356extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
357 unsigned long address,
358 pud_t *pudp);
359#endif
360
361#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
362struct mm_struct;
363static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
364{
365 pte_t old_pte = *ptep;
366 set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
367}
368#endif
369
370/*
371 * On some architectures hardware does not set page access bit when accessing
372 * memory page, it is responsibilty of software setting this bit. It brings
373 * out extra page fault penalty to track page access bit. For optimization page
374 * access bit can be set during all page fault flow on these arches.
375 * To be differentiate with macro pte_mkyoung, this macro is used on platforms
376 * where software maintains page access bit.
377 */
378#ifndef pte_sw_mkyoung
379static inline pte_t pte_sw_mkyoung(pte_t pte)
380{
381 return pte;
382}
383#define pte_sw_mkyoung pte_sw_mkyoung
384#endif
385
386#ifndef pte_savedwrite
387#define pte_savedwrite pte_write
388#endif
389
390#ifndef pte_mk_savedwrite
391#define pte_mk_savedwrite pte_mkwrite
392#endif
393
394#ifndef pte_clear_savedwrite
395#define pte_clear_savedwrite pte_wrprotect
396#endif
397
398#ifndef pmd_savedwrite
399#define pmd_savedwrite pmd_write
400#endif
401
402#ifndef pmd_mk_savedwrite
403#define pmd_mk_savedwrite pmd_mkwrite
404#endif
405
406#ifndef pmd_clear_savedwrite
407#define pmd_clear_savedwrite pmd_wrprotect
408#endif
409
410#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
411#ifdef CONFIG_TRANSPARENT_HUGEPAGE
412static inline void pmdp_set_wrprotect(struct mm_struct *mm,
413 unsigned long address, pmd_t *pmdp)
414{
415 pmd_t old_pmd = *pmdp;
416 set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
417}
418#else
419static inline void pmdp_set_wrprotect(struct mm_struct *mm,
420 unsigned long address, pmd_t *pmdp)
421{
422 BUILD_BUG();
423}
424#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
425#endif
426#ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
427#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
428static inline void pudp_set_wrprotect(struct mm_struct *mm,
429 unsigned long address, pud_t *pudp)
430{
431 pud_t old_pud = *pudp;
432
433 set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
434}
435#else
436static inline void pudp_set_wrprotect(struct mm_struct *mm,
437 unsigned long address, pud_t *pudp)
438{
439 BUILD_BUG();
440}
441#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
442#endif
443
444#ifndef pmdp_collapse_flush
445#ifdef CONFIG_TRANSPARENT_HUGEPAGE
446extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
447 unsigned long address, pmd_t *pmdp);
448#else
449static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
450 unsigned long address,
451 pmd_t *pmdp)
452{
453 BUILD_BUG();
454 return *pmdp;
455}
456#define pmdp_collapse_flush pmdp_collapse_flush
457#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
458#endif
459
460#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
461extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
462 pgtable_t pgtable);
463#endif
464
465#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
466extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
467#endif
468
469#ifdef CONFIG_TRANSPARENT_HUGEPAGE
470/*
471 * This is an implementation of pmdp_establish() that is only suitable for an
472 * architecture that doesn't have hardware dirty/accessed bits. In this case we
473 * can't race with CPU which sets these bits and non-atomic aproach is fine.
474 */
475static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
476 unsigned long address, pmd_t *pmdp, pmd_t pmd)
477{
478 pmd_t old_pmd = *pmdp;
479 set_pmd_at(vma->vm_mm, address, pmdp, pmd);
480 return old_pmd;
481}
482#endif
483
484#ifndef __HAVE_ARCH_PMDP_INVALIDATE
485extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
486 pmd_t *pmdp);
487#endif
488
489#ifndef __HAVE_ARCH_PTE_SAME
490static inline int pte_same(pte_t pte_a, pte_t pte_b)
491{
492 return pte_val(pte_a) == pte_val(pte_b);
493}
494#endif
495
496#ifndef __HAVE_ARCH_PTE_UNUSED
497/*
498 * Some architectures provide facilities to virtualization guests
499 * so that they can flag allocated pages as unused. This allows the
500 * host to transparently reclaim unused pages. This function returns
501 * whether the pte's page is unused.
502 */
503static inline int pte_unused(pte_t pte)
504{
505 return 0;
506}
507#endif
508
509#ifndef pte_access_permitted
510#define pte_access_permitted(pte, write) \
511 (pte_present(pte) && (!(write) || pte_write(pte)))
512#endif
513
514#ifndef pmd_access_permitted
515#define pmd_access_permitted(pmd, write) \
516 (pmd_present(pmd) && (!(write) || pmd_write(pmd)))
517#endif
518
519#ifndef pud_access_permitted
520#define pud_access_permitted(pud, write) \
521 (pud_present(pud) && (!(write) || pud_write(pud)))
522#endif
523
524#ifndef p4d_access_permitted
525#define p4d_access_permitted(p4d, write) \
526 (p4d_present(p4d) && (!(write) || p4d_write(p4d)))
527#endif
528
529#ifndef pgd_access_permitted
530#define pgd_access_permitted(pgd, write) \
531 (pgd_present(pgd) && (!(write) || pgd_write(pgd)))
532#endif
533
534#ifndef __HAVE_ARCH_PMD_SAME
535static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
536{
537 return pmd_val(pmd_a) == pmd_val(pmd_b);
538}
539
540static inline int pud_same(pud_t pud_a, pud_t pud_b)
541{
542 return pud_val(pud_a) == pud_val(pud_b);
543}
544#endif
545
546#ifndef __HAVE_ARCH_P4D_SAME
547static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
548{
549 return p4d_val(p4d_a) == p4d_val(p4d_b);
550}
551#endif
552
553#ifndef __HAVE_ARCH_PGD_SAME
554static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b)
555{
556 return pgd_val(pgd_a) == pgd_val(pgd_b);
557}
558#endif
559
560/*
561 * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
562 * TLB flush will be required as a result of the "set". For example, use
563 * in scenarios where it is known ahead of time that the routine is
564 * setting non-present entries, or re-setting an existing entry to the
565 * same value. Otherwise, use the typical "set" helpers and flush the
566 * TLB.
567 */
568#define set_pte_safe(ptep, pte) \
569({ \
570 WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
571 set_pte(ptep, pte); \
572})
573
574#define set_pmd_safe(pmdp, pmd) \
575({ \
576 WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
577 set_pmd(pmdp, pmd); \
578})
579
580#define set_pud_safe(pudp, pud) \
581({ \
582 WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
583 set_pud(pudp, pud); \
584})
585
586#define set_p4d_safe(p4dp, p4d) \
587({ \
588 WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
589 set_p4d(p4dp, p4d); \
590})
591
592#define set_pgd_safe(pgdp, pgd) \
593({ \
594 WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
595 set_pgd(pgdp, pgd); \
596})
597
598#ifndef __HAVE_ARCH_DO_SWAP_PAGE
599/*
600 * Some architectures support metadata associated with a page. When a
601 * page is being swapped out, this metadata must be saved so it can be
602 * restored when the page is swapped back in. SPARC M7 and newer
603 * processors support an ADI (Application Data Integrity) tag for the
604 * page as metadata for the page. arch_do_swap_page() can restore this
605 * metadata when a page is swapped back in.
606 */
607static inline void arch_do_swap_page(struct mm_struct *mm,
608 struct vm_area_struct *vma,
609 unsigned long addr,
610 pte_t pte, pte_t oldpte)
611{
612
613}
614#endif
615
616#ifndef __HAVE_ARCH_UNMAP_ONE
617/*
618 * Some architectures support metadata associated with a page. When a
619 * page is being swapped out, this metadata must be saved so it can be
620 * restored when the page is swapped back in. SPARC M7 and newer
621 * processors support an ADI (Application Data Integrity) tag for the
622 * page as metadata for the page. arch_unmap_one() can save this
623 * metadata on a swap-out of a page.
624 */
625static inline int arch_unmap_one(struct mm_struct *mm,
626 struct vm_area_struct *vma,
627 unsigned long addr,
628 pte_t orig_pte)
629{
630 return 0;
631}
632#endif
633
634#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
635#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
636#endif
637
638#ifndef __HAVE_ARCH_MOVE_PTE
639#define move_pte(pte, prot, old_addr, new_addr) (pte)
640#endif
641
642#ifndef pte_accessible
643# define pte_accessible(mm, pte) ((void)(pte), 1)
644#endif
645
646#ifndef flush_tlb_fix_spurious_fault
647#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
648#endif
649
650#ifndef pgprot_nx
651#define pgprot_nx(prot) (prot)
652#endif
653
654#ifndef pgprot_noncached
655#define pgprot_noncached(prot) (prot)
656#endif
657
658#ifndef pgprot_writecombine
659#define pgprot_writecombine pgprot_noncached
660#endif
661
662#ifndef pgprot_writethrough
663#define pgprot_writethrough pgprot_noncached
664#endif
665
666#ifndef pgprot_device
667#define pgprot_device pgprot_noncached
668#endif
669
670#ifndef pgprot_modify
671#define pgprot_modify pgprot_modify
672static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
673{
674 if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
675 newprot = pgprot_noncached(newprot);
676 if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
677 newprot = pgprot_writecombine(newprot);
678 if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
679 newprot = pgprot_device(newprot);
680 return newprot;
681}
682#endif
683
684/*
685 * When walking page tables, get the address of the next boundary,
686 * or the end address of the range if that comes earlier. Although no
687 * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
688 */
689
690#define pgd_addr_end(addr, end) \
691({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
692 (__boundary - 1 < (end) - 1)? __boundary: (end); \
693})
694
695#ifndef p4d_addr_end
696#define p4d_addr_end(addr, end) \
697({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
698 (__boundary - 1 < (end) - 1)? __boundary: (end); \
699})
700#endif
701
702#ifndef pud_addr_end
703#define pud_addr_end(addr, end) \
704({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
705 (__boundary - 1 < (end) - 1)? __boundary: (end); \
706})
707#endif
708
709#ifndef pmd_addr_end
710#define pmd_addr_end(addr, end) \
711({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
712 (__boundary - 1 < (end) - 1)? __boundary: (end); \
713})
714#endif
715
716/*
717 * When walking page tables, we usually want to skip any p?d_none entries;
718 * and any p?d_bad entries - reporting the error before resetting to none.
719 * Do the tests inline, but report and clear the bad entry in mm/memory.c.
720 */
721void pgd_clear_bad(pgd_t *);
722
723#ifndef __PAGETABLE_P4D_FOLDED
724void p4d_clear_bad(p4d_t *);
725#else
726#define p4d_clear_bad(p4d) do { } while (0)
727#endif
728
729#ifndef __PAGETABLE_PUD_FOLDED
730void pud_clear_bad(pud_t *);
731#else
732#define pud_clear_bad(p4d) do { } while (0)
733#endif
734
735void pmd_clear_bad(pmd_t *);
736
737static inline int pgd_none_or_clear_bad(pgd_t *pgd)
738{
739 if (pgd_none(*pgd))
740 return 1;
741 if (unlikely(pgd_bad(*pgd))) {
742 pgd_clear_bad(pgd);
743 return 1;
744 }
745 return 0;
746}
747
748static inline int p4d_none_or_clear_bad(p4d_t *p4d)
749{
750 if (p4d_none(*p4d))
751 return 1;
752 if (unlikely(p4d_bad(*p4d))) {
753 p4d_clear_bad(p4d);
754 return 1;
755 }
756 return 0;
757}
758
759static inline int pud_none_or_clear_bad(pud_t *pud)
760{
761 if (pud_none(*pud))
762 return 1;
763 if (unlikely(pud_bad(*pud))) {
764 pud_clear_bad(pud);
765 return 1;
766 }
767 return 0;
768}
769
770static inline int pmd_none_or_clear_bad(pmd_t *pmd)
771{
772 if (pmd_none(*pmd))
773 return 1;
774 if (unlikely(pmd_bad(*pmd))) {
775 pmd_clear_bad(pmd);
776 return 1;
777 }
778 return 0;
779}
780
781static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma,
782 unsigned long addr,
783 pte_t *ptep)
784{
785 /*
786 * Get the current pte state, but zero it out to make it
787 * non-present, preventing the hardware from asynchronously
788 * updating it.
789 */
790 return ptep_get_and_clear(vma->vm_mm, addr, ptep);
791}
792
793static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
794 unsigned long addr,
795 pte_t *ptep, pte_t pte)
796{
797 /*
798 * The pte is non-present, so there's no hardware state to
799 * preserve.
800 */
801 set_pte_at(vma->vm_mm, addr, ptep, pte);
802}
803
804#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
805/*
806 * Start a pte protection read-modify-write transaction, which
807 * protects against asynchronous hardware modifications to the pte.
808 * The intention is not to prevent the hardware from making pte
809 * updates, but to prevent any updates it may make from being lost.
810 *
811 * This does not protect against other software modifications of the
812 * pte; the appropriate pte lock must be held over the transation.
813 *
814 * Note that this interface is intended to be batchable, meaning that
815 * ptep_modify_prot_commit may not actually update the pte, but merely
816 * queue the update to be done at some later time. The update must be
817 * actually committed before the pte lock is released, however.
818 */
819static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
820 unsigned long addr,
821 pte_t *ptep)
822{
823 return __ptep_modify_prot_start(vma, addr, ptep);
824}
825
826/*
827 * Commit an update to a pte, leaving any hardware-controlled bits in
828 * the PTE unmodified.
829 */
830static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
831 unsigned long addr,
832 pte_t *ptep, pte_t old_pte, pte_t pte)
833{
834 __ptep_modify_prot_commit(vma, addr, ptep, pte);
835}
836#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
837#endif /* CONFIG_MMU */
838
839/*
840 * No-op macros that just return the current protection value. Defined here
841 * because these macros can be used used even if CONFIG_MMU is not defined.
842 */
843#ifndef pgprot_encrypted
844#define pgprot_encrypted(prot) (prot)
845#endif
846
847#ifndef pgprot_decrypted
848#define pgprot_decrypted(prot) (prot)
849#endif
850
851/*
852 * A facility to provide lazy MMU batching. This allows PTE updates and
853 * page invalidations to be delayed until a call to leave lazy MMU mode
854 * is issued. Some architectures may benefit from doing this, and it is
855 * beneficial for both shadow and direct mode hypervisors, which may batch
856 * the PTE updates which happen during this window. Note that using this
857 * interface requires that read hazards be removed from the code. A read
858 * hazard could result in the direct mode hypervisor case, since the actual
859 * write to the page tables may not yet have taken place, so reads though
860 * a raw PTE pointer after it has been modified are not guaranteed to be
861 * up to date. This mode can only be entered and left under the protection of
862 * the page table locks for all page tables which may be modified. In the UP
863 * case, this is required so that preemption is disabled, and in the SMP case,
864 * it must synchronize the delayed page table writes properly on other CPUs.
865 */
866#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
867#define arch_enter_lazy_mmu_mode() do {} while (0)
868#define arch_leave_lazy_mmu_mode() do {} while (0)
869#define arch_flush_lazy_mmu_mode() do {} while (0)
870#endif
871
872/*
873 * A facility to provide batching of the reload of page tables and
874 * other process state with the actual context switch code for
875 * paravirtualized guests. By convention, only one of the batched
876 * update (lazy) modes (CPU, MMU) should be active at any given time,
877 * entry should never be nested, and entry and exits should always be
878 * paired. This is for sanity of maintaining and reasoning about the
879 * kernel code. In this case, the exit (end of the context switch) is
880 * in architecture-specific code, and so doesn't need a generic
881 * definition.
882 */
883#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
884#define arch_start_context_switch(prev) do {} while (0)
885#endif
886
887#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
888#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
889static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
890{
891 return pmd;
892}
893
894static inline int pmd_swp_soft_dirty(pmd_t pmd)
895{
896 return 0;
897}
898
899static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
900{
901 return pmd;
902}
903#endif
904#else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
905static inline int pte_soft_dirty(pte_t pte)
906{
907 return 0;
908}
909
910static inline int pmd_soft_dirty(pmd_t pmd)
911{
912 return 0;
913}
914
915static inline pte_t pte_mksoft_dirty(pte_t pte)
916{
917 return pte;
918}
919
920static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
921{
922 return pmd;
923}
924
925static inline pte_t pte_clear_soft_dirty(pte_t pte)
926{
927 return pte;
928}
929
930static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
931{
932 return pmd;
933}
934
935static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
936{
937 return pte;
938}
939
940static inline int pte_swp_soft_dirty(pte_t pte)
941{
942 return 0;
943}
944
945static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
946{
947 return pte;
948}
949
950static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
951{
952 return pmd;
953}
954
955static inline int pmd_swp_soft_dirty(pmd_t pmd)
956{
957 return 0;
958}
959
960static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
961{
962 return pmd;
963}
964#endif
965
966#ifndef __HAVE_PFNMAP_TRACKING
967/*
968 * Interfaces that can be used by architecture code to keep track of
969 * memory type of pfn mappings specified by the remap_pfn_range,
970 * vmf_insert_pfn.
971 */
972
973/*
974 * track_pfn_remap is called when a _new_ pfn mapping is being established
975 * by remap_pfn_range() for physical range indicated by pfn and size.
976 */
977static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
978 unsigned long pfn, unsigned long addr,
979 unsigned long size)
980{
981 return 0;
982}
983
984/*
985 * track_pfn_insert is called when a _new_ single pfn is established
986 * by vmf_insert_pfn().
987 */
988static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
989 pfn_t pfn)
990{
991}
992
993/*
994 * track_pfn_copy is called when vma that is covering the pfnmap gets
995 * copied through copy_page_range().
996 */
997static inline int track_pfn_copy(struct vm_area_struct *vma)
998{
999 return 0;
1000}
1001
1002/*
1003 * untrack_pfn is called while unmapping a pfnmap for a region.
1004 * untrack can be called for a specific region indicated by pfn and size or
1005 * can be for the entire vma (in which case pfn, size are zero).
1006 */
1007static inline void untrack_pfn(struct vm_area_struct *vma,
1008 unsigned long pfn, unsigned long size)
1009{
1010}
1011
1012/*
1013 * untrack_pfn_moved is called while mremapping a pfnmap for a new region.
1014 */
1015static inline void untrack_pfn_moved(struct vm_area_struct *vma)
1016{
1017}
1018#else
1019extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
1020 unsigned long pfn, unsigned long addr,
1021 unsigned long size);
1022extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
1023 pfn_t pfn);
1024extern int track_pfn_copy(struct vm_area_struct *vma);
1025extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
1026 unsigned long size);
1027extern void untrack_pfn_moved(struct vm_area_struct *vma);
1028#endif
1029
1030#ifdef __HAVE_COLOR_ZERO_PAGE
1031static inline int is_zero_pfn(unsigned long pfn)
1032{
1033 extern unsigned long zero_pfn;
1034 unsigned long offset_from_zero_pfn = pfn - zero_pfn;
1035 return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
1036}
1037
1038#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
1039
1040#else
1041static inline int is_zero_pfn(unsigned long pfn)
1042{
1043 extern unsigned long zero_pfn;
1044 return pfn == zero_pfn;
1045}
1046
1047static inline unsigned long my_zero_pfn(unsigned long addr)
1048{
1049 extern unsigned long zero_pfn;
1050 return zero_pfn;
1051}
1052#endif
1053
1054#ifdef CONFIG_MMU
1055
1056#ifndef CONFIG_TRANSPARENT_HUGEPAGE
1057static inline int pmd_trans_huge(pmd_t pmd)
1058{
1059 return 0;
1060}
1061#ifndef pmd_write
1062static inline int pmd_write(pmd_t pmd)
1063{
1064 BUG();
1065 return 0;
1066}
1067#endif /* pmd_write */
1068#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1069
1070#ifndef pud_write
1071static inline int pud_write(pud_t pud)
1072{
1073 BUG();
1074 return 0;
1075}
1076#endif /* pud_write */
1077
1078#if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
1079static inline int pmd_devmap(pmd_t pmd)
1080{
1081 return 0;
1082}
1083static inline int pud_devmap(pud_t pud)
1084{
1085 return 0;
1086}
1087static inline int pgd_devmap(pgd_t pgd)
1088{
1089 return 0;
1090}
1091#endif
1092
1093#if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
1094 (defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
1095 !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
1096static inline int pud_trans_huge(pud_t pud)
1097{
1098 return 0;
1099}
1100#endif
1101
1102/* See pmd_none_or_trans_huge_or_clear_bad for discussion. */
1103static inline int pud_none_or_trans_huge_or_dev_or_clear_bad(pud_t *pud)
1104{
1105 pud_t pudval = READ_ONCE(*pud);
1106
1107 if (pud_none(pudval) || pud_trans_huge(pudval) || pud_devmap(pudval))
1108 return 1;
1109 if (unlikely(pud_bad(pudval))) {
1110 pud_clear_bad(pud);
1111 return 1;
1112 }
1113 return 0;
1114}
1115
1116/* See pmd_trans_unstable for discussion. */
1117static inline int pud_trans_unstable(pud_t *pud)
1118{
1119#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
1120 defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
1121 return pud_none_or_trans_huge_or_dev_or_clear_bad(pud);
1122#else
1123 return 0;
1124#endif
1125}
1126
1127#ifndef pmd_read_atomic
1128static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
1129{
1130 /*
1131 * Depend on compiler for an atomic pmd read. NOTE: this is
1132 * only going to work, if the pmdval_t isn't larger than
1133 * an unsigned long.
1134 */
1135 return *pmdp;
1136}
1137#endif
1138
1139#ifndef arch_needs_pgtable_deposit
1140#define arch_needs_pgtable_deposit() (false)
1141#endif
1142/*
1143 * This function is meant to be used by sites walking pagetables with
1144 * the mmap_lock held in read mode to protect against MADV_DONTNEED and
1145 * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
1146 * into a null pmd and the transhuge page fault can convert a null pmd
1147 * into an hugepmd or into a regular pmd (if the hugepage allocation
1148 * fails). While holding the mmap_lock in read mode the pmd becomes
1149 * stable and stops changing under us only if it's not null and not a
1150 * transhuge pmd. When those races occurs and this function makes a
1151 * difference vs the standard pmd_none_or_clear_bad, the result is
1152 * undefined so behaving like if the pmd was none is safe (because it
1153 * can return none anyway). The compiler level barrier() is critically
1154 * important to compute the two checks atomically on the same pmdval.
1155 *
1156 * For 32bit kernels with a 64bit large pmd_t this automatically takes
1157 * care of reading the pmd atomically to avoid SMP race conditions
1158 * against pmd_populate() when the mmap_lock is hold for reading by the
1159 * caller (a special atomic read not done by "gcc" as in the generic
1160 * version above, is also needed when THP is disabled because the page
1161 * fault can populate the pmd from under us).
1162 */
1163static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
1164{
1165 pmd_t pmdval = pmd_read_atomic(pmd);
1166 /*
1167 * The barrier will stabilize the pmdval in a register or on
1168 * the stack so that it will stop changing under the code.
1169 *
1170 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
1171 * pmd_read_atomic is allowed to return a not atomic pmdval
1172 * (for example pointing to an hugepage that has never been
1173 * mapped in the pmd). The below checks will only care about
1174 * the low part of the pmd with 32bit PAE x86 anyway, with the
1175 * exception of pmd_none(). So the important thing is that if
1176 * the low part of the pmd is found null, the high part will
1177 * be also null or the pmd_none() check below would be
1178 * confused.
1179 */
1180#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1181 barrier();
1182#endif
1183 /*
1184 * !pmd_present() checks for pmd migration entries
1185 *
1186 * The complete check uses is_pmd_migration_entry() in linux/swapops.h
1187 * But using that requires moving current function and pmd_trans_unstable()
1188 * to linux/swapops.h to resovle dependency, which is too much code move.
1189 *
1190 * !pmd_present() is equivalent to is_pmd_migration_entry() currently,
1191 * because !pmd_present() pages can only be under migration not swapped
1192 * out.
1193 *
1194 * pmd_none() is preseved for future condition checks on pmd migration
1195 * entries and not confusing with this function name, although it is
1196 * redundant with !pmd_present().
1197 */
1198 if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
1199 (IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
1200 return 1;
1201 if (unlikely(pmd_bad(pmdval))) {
1202 pmd_clear_bad(pmd);
1203 return 1;
1204 }
1205 return 0;
1206}
1207
1208/*
1209 * This is a noop if Transparent Hugepage Support is not built into
1210 * the kernel. Otherwise it is equivalent to
1211 * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
1212 * places that already verified the pmd is not none and they want to
1213 * walk ptes while holding the mmap sem in read mode (write mode don't
1214 * need this). If THP is not enabled, the pmd can't go away under the
1215 * code even if MADV_DONTNEED runs, but if THP is enabled we need to
1216 * run a pmd_trans_unstable before walking the ptes after
1217 * split_huge_pmd returns (because it may have run when the pmd become
1218 * null, but then a page fault can map in a THP and not a regular page).
1219 */
1220static inline int pmd_trans_unstable(pmd_t *pmd)
1221{
1222#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1223 return pmd_none_or_trans_huge_or_clear_bad(pmd);
1224#else
1225 return 0;
1226#endif
1227}
1228
1229#ifndef CONFIG_NUMA_BALANCING
1230/*
1231 * Technically a PTE can be PROTNONE even when not doing NUMA balancing but
1232 * the only case the kernel cares is for NUMA balancing and is only ever set
1233 * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
1234 * _PAGE_PROTNONE so by by default, implement the helper as "always no". It
1235 * is the responsibility of the caller to distinguish between PROT_NONE
1236 * protections and NUMA hinting fault protections.
1237 */
1238static inline int pte_protnone(pte_t pte)
1239{
1240 return 0;
1241}
1242
1243static inline int pmd_protnone(pmd_t pmd)
1244{
1245 return 0;
1246}
1247#endif /* CONFIG_NUMA_BALANCING */
1248
1249#endif /* CONFIG_MMU */
1250
1251#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
1252
1253#ifndef __PAGETABLE_P4D_FOLDED
1254int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
1255int p4d_clear_huge(p4d_t *p4d);
1256#else
1257static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
1258{
1259 return 0;
1260}
1261static inline int p4d_clear_huge(p4d_t *p4d)
1262{
1263 return 0;
1264}
1265#endif /* !__PAGETABLE_P4D_FOLDED */
1266
1267int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
1268int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
1269int pud_clear_huge(pud_t *pud);
1270int pmd_clear_huge(pmd_t *pmd);
1271int p4d_free_pud_page(p4d_t *p4d, unsigned long addr);
1272int pud_free_pmd_page(pud_t *pud, unsigned long addr);
1273int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
1274#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
1275static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
1276{
1277 return 0;
1278}
1279static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
1280{
1281 return 0;
1282}
1283static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
1284{
1285 return 0;
1286}
1287static inline int p4d_clear_huge(p4d_t *p4d)
1288{
1289 return 0;
1290}
1291static inline int pud_clear_huge(pud_t *pud)
1292{
1293 return 0;
1294}
1295static inline int pmd_clear_huge(pmd_t *pmd)
1296{
1297 return 0;
1298}
1299static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
1300{
1301 return 0;
1302}
1303static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
1304{
1305 return 0;
1306}
1307static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
1308{
1309 return 0;
1310}
1311#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
1312
1313#ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
1314#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1315/*
1316 * ARCHes with special requirements for evicting THP backing TLB entries can
1317 * implement this. Otherwise also, it can help optimize normal TLB flush in
1318 * THP regime. stock flush_tlb_range() typically has optimization to nuke the
1319 * entire TLB TLB if flush span is greater than a threshold, which will
1320 * likely be true for a single huge page. Thus a single thp flush will
1321 * invalidate the entire TLB which is not desitable.
1322 * e.g. see arch/arc: flush_pmd_tlb_range
1323 */
1324#define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
1325#define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
1326#else
1327#define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG()
1328#define flush_pud_tlb_range(vma, addr, end) BUILD_BUG()
1329#endif
1330#endif
1331
1332struct file;
1333int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
1334 unsigned long size, pgprot_t *vma_prot);
1335
1336#ifndef CONFIG_X86_ESPFIX64
1337static inline void init_espfix_bsp(void) { }
1338#endif
1339
1340extern void __init pgtable_cache_init(void);
1341
1342#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
1343static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
1344{
1345 return true;
1346}
1347
1348static inline bool arch_has_pfn_modify_check(void)
1349{
1350 return false;
1351}
1352#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
1353
1354/*
1355 * Architecture PAGE_KERNEL_* fallbacks
1356 *
1357 * Some architectures don't define certain PAGE_KERNEL_* flags. This is either
1358 * because they really don't support them, or the port needs to be updated to
1359 * reflect the required functionality. Below are a set of relatively safe
1360 * fallbacks, as best effort, which we can count on in lieu of the architectures
1361 * not defining them on their own yet.
1362 */
1363
1364#ifndef PAGE_KERNEL_RO
1365# define PAGE_KERNEL_RO PAGE_KERNEL
1366#endif
1367
1368#ifndef PAGE_KERNEL_EXEC
1369# define PAGE_KERNEL_EXEC PAGE_KERNEL
1370#endif
1371
1372/*
1373 * Page Table Modification bits for pgtbl_mod_mask.
1374 *
1375 * These are used by the p?d_alloc_track*() set of functions an in the generic
1376 * vmalloc/ioremap code to track at which page-table levels entries have been
1377 * modified. Based on that the code can better decide when vmalloc and ioremap
1378 * mapping changes need to be synchronized to other page-tables in the system.
1379 */
1380#define __PGTBL_PGD_MODIFIED 0
1381#define __PGTBL_P4D_MODIFIED 1
1382#define __PGTBL_PUD_MODIFIED 2
1383#define __PGTBL_PMD_MODIFIED 3
1384#define __PGTBL_PTE_MODIFIED 4
1385
1386#define PGTBL_PGD_MODIFIED BIT(__PGTBL_PGD_MODIFIED)
1387#define PGTBL_P4D_MODIFIED BIT(__PGTBL_P4D_MODIFIED)
1388#define PGTBL_PUD_MODIFIED BIT(__PGTBL_PUD_MODIFIED)
1389#define PGTBL_PMD_MODIFIED BIT(__PGTBL_PMD_MODIFIED)
1390#define PGTBL_PTE_MODIFIED BIT(__PGTBL_PTE_MODIFIED)
1391
1392/* Page-Table Modification Mask */
1393typedef unsigned int pgtbl_mod_mask;
1394
1395#endif /* !__ASSEMBLY__ */
1396
1397#ifndef io_remap_pfn_range
1398#define io_remap_pfn_range remap_pfn_range
1399#endif
1400
1401#ifndef has_transparent_hugepage
1402#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1403#define has_transparent_hugepage() 1
1404#else
1405#define has_transparent_hugepage() 0
1406#endif
1407#endif
1408
1409/*
1410 * On some architectures it depends on the mm if the p4d/pud or pmd
1411 * layer of the page table hierarchy is folded or not.
1412 */
1413#ifndef mm_p4d_folded
1414#define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED)
1415#endif
1416
1417#ifndef mm_pud_folded
1418#define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED)
1419#endif
1420
1421#ifndef mm_pmd_folded
1422#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
1423#endif
1424
1425/*
1426 * p?d_leaf() - true if this entry is a final mapping to a physical address.
1427 * This differs from p?d_huge() by the fact that they are always available (if
1428 * the architecture supports large pages at the appropriate level) even
1429 * if CONFIG_HUGETLB_PAGE is not defined.
1430 * Only meaningful when called on a valid entry.
1431 */
1432#ifndef pgd_leaf
1433#define pgd_leaf(x) 0
1434#endif
1435#ifndef p4d_leaf
1436#define p4d_leaf(x) 0
1437#endif
1438#ifndef pud_leaf
1439#define pud_leaf(x) 0
1440#endif
1441#ifndef pmd_leaf
1442#define pmd_leaf(x) 0
1443#endif
1444
1445#endif /* _LINUX_PGTABLE_H */