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CommitLineData
1da177e4
LT
1#ifndef _ASM_GENERIC_PGTABLE_H
2#define _ASM_GENERIC_PGTABLE_H
3
673eae82 4#ifndef __ASSEMBLY__
9535239f 5#ifdef CONFIG_MMU
673eae82 6
fbd71844 7#include <linux/mm_types.h>
187f1882 8#include <linux/bug.h>
fbd71844 9
6ee8630e
HD
10/*
11 * On almost all architectures and configurations, 0 can be used as the
12 * upper ceiling to free_pgtables(): on many architectures it has the same
13 * effect as using TASK_SIZE. However, there is one configuration which
14 * must impose a more careful limit, to avoid freeing kernel pgtables.
15 */
16#ifndef USER_PGTABLES_CEILING
17#define USER_PGTABLES_CEILING 0UL
18#endif
19
1da177e4 20#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
e2cda322
AA
21extern int ptep_set_access_flags(struct vm_area_struct *vma,
22 unsigned long address, pte_t *ptep,
23 pte_t entry, int dirty);
24#endif
25
26#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
27extern int pmdp_set_access_flags(struct vm_area_struct *vma,
28 unsigned long address, pmd_t *pmdp,
29 pmd_t entry, int dirty);
1da177e4
LT
30#endif
31
32#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
e2cda322
AA
33static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
34 unsigned long address,
35 pte_t *ptep)
36{
37 pte_t pte = *ptep;
38 int r = 1;
39 if (!pte_young(pte))
40 r = 0;
41 else
42 set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
43 return r;
44}
45#endif
46
47#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
48#ifdef CONFIG_TRANSPARENT_HUGEPAGE
49static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
50 unsigned long address,
51 pmd_t *pmdp)
52{
53 pmd_t pmd = *pmdp;
54 int r = 1;
55 if (!pmd_young(pmd))
56 r = 0;
57 else
58 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
59 return r;
60}
61#else /* CONFIG_TRANSPARENT_HUGEPAGE */
62static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
63 unsigned long address,
64 pmd_t *pmdp)
65{
66 BUG();
67 return 0;
68}
69#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1da177e4
LT
70#endif
71
72#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
e2cda322
AA
73int ptep_clear_flush_young(struct vm_area_struct *vma,
74 unsigned long address, pte_t *ptep);
75#endif
76
77#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
78int pmdp_clear_flush_young(struct vm_area_struct *vma,
79 unsigned long address, pmd_t *pmdp);
1da177e4
LT
80#endif
81
1da177e4 82#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
e2cda322
AA
83static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
84 unsigned long address,
85 pte_t *ptep)
86{
87 pte_t pte = *ptep;
88 pte_clear(mm, address, ptep);
89 return pte;
90}
91#endif
92
93#ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
94#ifdef CONFIG_TRANSPARENT_HUGEPAGE
95static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
96 unsigned long address,
97 pmd_t *pmdp)
98{
99 pmd_t pmd = *pmdp;
2d28a227 100 pmd_clear(pmdp);
e2cda322 101 return pmd;
49b24d6b 102}
e2cda322 103#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1da177e4
LT
104#endif
105
a600388d 106#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
e2cda322
AA
107static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
108 unsigned long address, pte_t *ptep,
109 int full)
110{
111 pte_t pte;
112 pte = ptep_get_and_clear(mm, address, ptep);
113 return pte;
114}
a600388d
ZA
115#endif
116
9888a1ca
ZA
117/*
118 * Some architectures may be able to avoid expensive synchronization
119 * primitives when modifications are made to PTE's which are already
120 * not present, or in the process of an address space destruction.
121 */
122#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
e2cda322
AA
123static inline void pte_clear_not_present_full(struct mm_struct *mm,
124 unsigned long address,
125 pte_t *ptep,
126 int full)
127{
128 pte_clear(mm, address, ptep);
129}
a600388d
ZA
130#endif
131
1da177e4 132#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
e2cda322
AA
133extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
134 unsigned long address,
135 pte_t *ptep);
136#endif
137
138#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
139extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
140 unsigned long address,
141 pmd_t *pmdp);
1da177e4
LT
142#endif
143
144#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
8c65b4a6 145struct mm_struct;
1da177e4
LT
146static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
147{
148 pte_t old_pte = *ptep;
149 set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
150}
151#endif
152
e2cda322
AA
153#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
154#ifdef CONFIG_TRANSPARENT_HUGEPAGE
155static inline void pmdp_set_wrprotect(struct mm_struct *mm,
156 unsigned long address, pmd_t *pmdp)
157{
158 pmd_t old_pmd = *pmdp;
159 set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
160}
161#else /* CONFIG_TRANSPARENT_HUGEPAGE */
162static inline void pmdp_set_wrprotect(struct mm_struct *mm,
163 unsigned long address, pmd_t *pmdp)
164{
165 BUG();
166}
167#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
168#endif
169
170#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
73636b1a
CM
171extern void pmdp_splitting_flush(struct vm_area_struct *vma,
172 unsigned long address, pmd_t *pmdp);
e2cda322
AA
173#endif
174
e3ebcf64 175#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
6b0b50b0
AK
176extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
177 pgtable_t pgtable);
e3ebcf64
GS
178#endif
179
180#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
6b0b50b0 181extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
e3ebcf64
GS
182#endif
183
46dcde73
GS
184#ifndef __HAVE_ARCH_PMDP_INVALIDATE
185extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
186 pmd_t *pmdp);
187#endif
188
1da177e4 189#ifndef __HAVE_ARCH_PTE_SAME
e2cda322
AA
190static inline int pte_same(pte_t pte_a, pte_t pte_b)
191{
192 return pte_val(pte_a) == pte_val(pte_b);
193}
194#endif
195
45961722
KW
196#ifndef __HAVE_ARCH_PTE_UNUSED
197/*
198 * Some architectures provide facilities to virtualization guests
199 * so that they can flag allocated pages as unused. This allows the
200 * host to transparently reclaim unused pages. This function returns
201 * whether the pte's page is unused.
202 */
203static inline int pte_unused(pte_t pte)
204{
205 return 0;
206}
207#endif
208
e2cda322
AA
209#ifndef __HAVE_ARCH_PMD_SAME
210#ifdef CONFIG_TRANSPARENT_HUGEPAGE
211static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
212{
213 return pmd_val(pmd_a) == pmd_val(pmd_b);
214}
215#else /* CONFIG_TRANSPARENT_HUGEPAGE */
216static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
217{
218 BUG();
219 return 0;
220}
221#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1da177e4
LT
222#endif
223
1da177e4
LT
224#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
225#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
226#endif
227
0b0968a3 228#ifndef __HAVE_ARCH_MOVE_PTE
8b1f3124 229#define move_pte(pte, prot, old_addr, new_addr) (pte)
8b1f3124
NP
230#endif
231
2c3cf556 232#ifndef pte_accessible
20841405 233# define pte_accessible(mm, pte) ((void)(pte), 1)
2c3cf556
RR
234#endif
235
c46a7c81
MG
236#ifndef pte_present_nonuma
237#define pte_present_nonuma(pte) pte_present(pte)
238#endif
239
61c77326
SL
240#ifndef flush_tlb_fix_spurious_fault
241#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
242#endif
243
0634a632
PM
244#ifndef pgprot_noncached
245#define pgprot_noncached(prot) (prot)
246#endif
247
2520bd31 248#ifndef pgprot_writecombine
249#define pgprot_writecombine pgprot_noncached
250#endif
251
8b921acf
LD
252#ifndef pgprot_device
253#define pgprot_device pgprot_noncached
254#endif
255
64e45507
PF
256#ifndef pgprot_modify
257#define pgprot_modify pgprot_modify
258static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
259{
260 if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
261 newprot = pgprot_noncached(newprot);
262 if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
263 newprot = pgprot_writecombine(newprot);
264 if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
265 newprot = pgprot_device(newprot);
266 return newprot;
267}
268#endif
269
1da177e4 270/*
8f6c99c1
HD
271 * When walking page tables, get the address of the next boundary,
272 * or the end address of the range if that comes earlier. Although no
273 * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
1da177e4
LT
274 */
275
1da177e4
LT
276#define pgd_addr_end(addr, end) \
277({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
278 (__boundary - 1 < (end) - 1)? __boundary: (end); \
279})
1da177e4
LT
280
281#ifndef pud_addr_end
282#define pud_addr_end(addr, end) \
283({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
284 (__boundary - 1 < (end) - 1)? __boundary: (end); \
285})
286#endif
287
288#ifndef pmd_addr_end
289#define pmd_addr_end(addr, end) \
290({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
291 (__boundary - 1 < (end) - 1)? __boundary: (end); \
292})
293#endif
294
1da177e4
LT
295/*
296 * When walking page tables, we usually want to skip any p?d_none entries;
297 * and any p?d_bad entries - reporting the error before resetting to none.
298 * Do the tests inline, but report and clear the bad entry in mm/memory.c.
299 */
300void pgd_clear_bad(pgd_t *);
301void pud_clear_bad(pud_t *);
302void pmd_clear_bad(pmd_t *);
303
304static inline int pgd_none_or_clear_bad(pgd_t *pgd)
305{
306 if (pgd_none(*pgd))
307 return 1;
308 if (unlikely(pgd_bad(*pgd))) {
309 pgd_clear_bad(pgd);
310 return 1;
311 }
312 return 0;
313}
314
315static inline int pud_none_or_clear_bad(pud_t *pud)
316{
317 if (pud_none(*pud))
318 return 1;
319 if (unlikely(pud_bad(*pud))) {
320 pud_clear_bad(pud);
321 return 1;
322 }
323 return 0;
324}
325
326static inline int pmd_none_or_clear_bad(pmd_t *pmd)
327{
328 if (pmd_none(*pmd))
329 return 1;
330 if (unlikely(pmd_bad(*pmd))) {
331 pmd_clear_bad(pmd);
332 return 1;
333 }
334 return 0;
335}
9535239f 336
1ea0704e
JF
337static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
338 unsigned long addr,
339 pte_t *ptep)
340{
341 /*
342 * Get the current pte state, but zero it out to make it
343 * non-present, preventing the hardware from asynchronously
344 * updating it.
345 */
346 return ptep_get_and_clear(mm, addr, ptep);
347}
348
349static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
350 unsigned long addr,
351 pte_t *ptep, pte_t pte)
352{
353 /*
354 * The pte is non-present, so there's no hardware state to
355 * preserve.
356 */
357 set_pte_at(mm, addr, ptep, pte);
358}
359
360#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
361/*
362 * Start a pte protection read-modify-write transaction, which
363 * protects against asynchronous hardware modifications to the pte.
364 * The intention is not to prevent the hardware from making pte
365 * updates, but to prevent any updates it may make from being lost.
366 *
367 * This does not protect against other software modifications of the
368 * pte; the appropriate pte lock must be held over the transation.
369 *
370 * Note that this interface is intended to be batchable, meaning that
371 * ptep_modify_prot_commit may not actually update the pte, but merely
372 * queue the update to be done at some later time. The update must be
373 * actually committed before the pte lock is released, however.
374 */
375static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
376 unsigned long addr,
377 pte_t *ptep)
378{
379 return __ptep_modify_prot_start(mm, addr, ptep);
380}
381
382/*
383 * Commit an update to a pte, leaving any hardware-controlled bits in
384 * the PTE unmodified.
385 */
386static inline void ptep_modify_prot_commit(struct mm_struct *mm,
387 unsigned long addr,
388 pte_t *ptep, pte_t pte)
389{
390 __ptep_modify_prot_commit(mm, addr, ptep, pte);
391}
392#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
fe1a6875 393#endif /* CONFIG_MMU */
1ea0704e 394
9535239f
GU
395/*
396 * A facility to provide lazy MMU batching. This allows PTE updates and
397 * page invalidations to be delayed until a call to leave lazy MMU mode
398 * is issued. Some architectures may benefit from doing this, and it is
399 * beneficial for both shadow and direct mode hypervisors, which may batch
400 * the PTE updates which happen during this window. Note that using this
401 * interface requires that read hazards be removed from the code. A read
402 * hazard could result in the direct mode hypervisor case, since the actual
403 * write to the page tables may not yet have taken place, so reads though
404 * a raw PTE pointer after it has been modified are not guaranteed to be
405 * up to date. This mode can only be entered and left under the protection of
406 * the page table locks for all page tables which may be modified. In the UP
407 * case, this is required so that preemption is disabled, and in the SMP case,
408 * it must synchronize the delayed page table writes properly on other CPUs.
409 */
410#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
411#define arch_enter_lazy_mmu_mode() do {} while (0)
412#define arch_leave_lazy_mmu_mode() do {} while (0)
413#define arch_flush_lazy_mmu_mode() do {} while (0)
414#endif
415
416/*
7fd7d83d
JF
417 * A facility to provide batching of the reload of page tables and
418 * other process state with the actual context switch code for
419 * paravirtualized guests. By convention, only one of the batched
420 * update (lazy) modes (CPU, MMU) should be active at any given time,
421 * entry should never be nested, and entry and exits should always be
422 * paired. This is for sanity of maintaining and reasoning about the
423 * kernel code. In this case, the exit (end of the context switch) is
424 * in architecture-specific code, and so doesn't need a generic
425 * definition.
9535239f 426 */
7fd7d83d 427#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
224101ed 428#define arch_start_context_switch(prev) do {} while (0)
9535239f
GU
429#endif
430
0f8975ec
PE
431#ifndef CONFIG_HAVE_ARCH_SOFT_DIRTY
432static inline int pte_soft_dirty(pte_t pte)
433{
434 return 0;
435}
436
437static inline int pmd_soft_dirty(pmd_t pmd)
438{
439 return 0;
440}
441
442static inline pte_t pte_mksoft_dirty(pte_t pte)
443{
444 return pte;
445}
446
447static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
448{
449 return pmd;
450}
179ef71c
CG
451
452static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
453{
454 return pte;
455}
456
457static inline int pte_swp_soft_dirty(pte_t pte)
458{
459 return 0;
460}
461
462static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
463{
464 return pte;
465}
41bb3476
CG
466
467static inline pte_t pte_file_clear_soft_dirty(pte_t pte)
468{
469 return pte;
470}
471
472static inline pte_t pte_file_mksoft_dirty(pte_t pte)
473{
474 return pte;
475}
476
477static inline int pte_file_soft_dirty(pte_t pte)
478{
479 return 0;
480}
0f8975ec
PE
481#endif
482
34801ba9 483#ifndef __HAVE_PFNMAP_TRACKING
484/*
5180da41
SS
485 * Interfaces that can be used by architecture code to keep track of
486 * memory type of pfn mappings specified by the remap_pfn_range,
487 * vm_insert_pfn.
488 */
489
490/*
491 * track_pfn_remap is called when a _new_ pfn mapping is being established
492 * by remap_pfn_range() for physical range indicated by pfn and size.
34801ba9 493 */
5180da41 494static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
b3b9c293
KK
495 unsigned long pfn, unsigned long addr,
496 unsigned long size)
34801ba9 497{
498 return 0;
499}
500
501/*
5180da41
SS
502 * track_pfn_insert is called when a _new_ single pfn is established
503 * by vm_insert_pfn().
504 */
505static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
506 unsigned long pfn)
507{
508 return 0;
509}
510
511/*
512 * track_pfn_copy is called when vma that is covering the pfnmap gets
34801ba9 513 * copied through copy_page_range().
514 */
5180da41 515static inline int track_pfn_copy(struct vm_area_struct *vma)
34801ba9 516{
517 return 0;
518}
519
520/*
34801ba9 521 * untrack_pfn_vma is called while unmapping a pfnmap for a region.
522 * untrack can be called for a specific region indicated by pfn and size or
5180da41 523 * can be for the entire vma (in which case pfn, size are zero).
34801ba9 524 */
5180da41
SS
525static inline void untrack_pfn(struct vm_area_struct *vma,
526 unsigned long pfn, unsigned long size)
34801ba9 527{
528}
529#else
5180da41 530extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
b3b9c293
KK
531 unsigned long pfn, unsigned long addr,
532 unsigned long size);
5180da41
SS
533extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
534 unsigned long pfn);
535extern int track_pfn_copy(struct vm_area_struct *vma);
536extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
537 unsigned long size);
34801ba9 538#endif
539
816422ad
KS
540#ifdef __HAVE_COLOR_ZERO_PAGE
541static inline int is_zero_pfn(unsigned long pfn)
542{
543 extern unsigned long zero_pfn;
544 unsigned long offset_from_zero_pfn = pfn - zero_pfn;
545 return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
546}
547
2f91ec8c
KS
548#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
549
816422ad
KS
550#else
551static inline int is_zero_pfn(unsigned long pfn)
552{
553 extern unsigned long zero_pfn;
554 return pfn == zero_pfn;
555}
556
557static inline unsigned long my_zero_pfn(unsigned long addr)
558{
559 extern unsigned long zero_pfn;
560 return zero_pfn;
561}
562#endif
563
1a5a9906
AA
564#ifdef CONFIG_MMU
565
5f6e8da7
AA
566#ifndef CONFIG_TRANSPARENT_HUGEPAGE
567static inline int pmd_trans_huge(pmd_t pmd)
568{
569 return 0;
570}
571static inline int pmd_trans_splitting(pmd_t pmd)
572{
573 return 0;
574}
e2cda322
AA
575#ifndef __HAVE_ARCH_PMD_WRITE
576static inline int pmd_write(pmd_t pmd)
577{
578 BUG();
579 return 0;
580}
581#endif /* __HAVE_ARCH_PMD_WRITE */
1a5a9906
AA
582#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
583
26c19178
AA
584#ifndef pmd_read_atomic
585static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
586{
587 /*
588 * Depend on compiler for an atomic pmd read. NOTE: this is
589 * only going to work, if the pmdval_t isn't larger than
590 * an unsigned long.
591 */
592 return *pmdp;
593}
594#endif
595
b3084f4d
AK
596#ifndef pmd_move_must_withdraw
597static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
598 spinlock_t *old_pmd_ptl)
599{
600 /*
601 * With split pmd lock we also need to move preallocated
602 * PTE page table if new_pmd is on different PMD page table.
603 */
604 return new_pmd_ptl != old_pmd_ptl;
605}
606#endif
607
1a5a9906
AA
608/*
609 * This function is meant to be used by sites walking pagetables with
610 * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
611 * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
612 * into a null pmd and the transhuge page fault can convert a null pmd
613 * into an hugepmd or into a regular pmd (if the hugepage allocation
614 * fails). While holding the mmap_sem in read mode the pmd becomes
615 * stable and stops changing under us only if it's not null and not a
616 * transhuge pmd. When those races occurs and this function makes a
617 * difference vs the standard pmd_none_or_clear_bad, the result is
618 * undefined so behaving like if the pmd was none is safe (because it
619 * can return none anyway). The compiler level barrier() is critically
620 * important to compute the two checks atomically on the same pmdval.
26c19178
AA
621 *
622 * For 32bit kernels with a 64bit large pmd_t this automatically takes
623 * care of reading the pmd atomically to avoid SMP race conditions
624 * against pmd_populate() when the mmap_sem is hold for reading by the
625 * caller (a special atomic read not done by "gcc" as in the generic
626 * version above, is also needed when THP is disabled because the page
627 * fault can populate the pmd from under us).
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628 */
629static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
630{
26c19178 631 pmd_t pmdval = pmd_read_atomic(pmd);
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632 /*
633 * The barrier will stabilize the pmdval in a register or on
634 * the stack so that it will stop changing under the code.
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635 *
636 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
637 * pmd_read_atomic is allowed to return a not atomic pmdval
638 * (for example pointing to an hugepage that has never been
639 * mapped in the pmd). The below checks will only care about
640 * the low part of the pmd with 32bit PAE x86 anyway, with the
641 * exception of pmd_none(). So the important thing is that if
642 * the low part of the pmd is found null, the high part will
643 * be also null or the pmd_none() check below would be
644 * confused.
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645 */
646#ifdef CONFIG_TRANSPARENT_HUGEPAGE
647 barrier();
648#endif
ee53664b 649 if (pmd_none(pmdval) || pmd_trans_huge(pmdval))
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650 return 1;
651 if (unlikely(pmd_bad(pmdval))) {
ee53664b 652 pmd_clear_bad(pmd);
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653 return 1;
654 }
655 return 0;
656}
657
658/*
659 * This is a noop if Transparent Hugepage Support is not built into
660 * the kernel. Otherwise it is equivalent to
661 * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
662 * places that already verified the pmd is not none and they want to
663 * walk ptes while holding the mmap sem in read mode (write mode don't
664 * need this). If THP is not enabled, the pmd can't go away under the
665 * code even if MADV_DONTNEED runs, but if THP is enabled we need to
666 * run a pmd_trans_unstable before walking the ptes after
667 * split_huge_page_pmd returns (because it may have run when the pmd
668 * become null, but then a page fault can map in a THP and not a
669 * regular page).
670 */
671static inline int pmd_trans_unstable(pmd_t *pmd)
672{
673#ifdef CONFIG_TRANSPARENT_HUGEPAGE
674 return pmd_none_or_trans_huge_or_clear_bad(pmd);
675#else
676 return 0;
5f6e8da7 677#endif
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678}
679
be3a7284 680#ifdef CONFIG_NUMA_BALANCING
be3a7284 681/*
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682 * _PAGE_NUMA distinguishes between an unmapped page table entry, an entry that
683 * is protected for PROT_NONE and a NUMA hinting fault entry. If the
684 * architecture defines __PAGE_PROTNONE then it should take that into account
685 * but those that do not can rely on the fact that the NUMA hinting scanner
686 * skips inaccessible VMAs.
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687 *
688 * pte/pmd_present() returns true if pte/pmd_numa returns true. Page
689 * fault triggers on those regions if pte/pmd_numa returns true
690 * (because _PAGE_PRESENT is not set).
691 */
692#ifndef pte_numa
693static inline int pte_numa(pte_t pte)
694{
6a33979d 695 return ptenuma_flags(pte) == _PAGE_NUMA;
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696}
697#endif
698
699#ifndef pmd_numa
700static inline int pmd_numa(pmd_t pmd)
701{
6a33979d 702 return pmdnuma_flags(pmd) == _PAGE_NUMA;
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703}
704#endif
705
706/*
707 * pte/pmd_mknuma sets the _PAGE_ACCESSED bitflag automatically
708 * because they're called by the NUMA hinting minor page fault. If we
709 * wouldn't set the _PAGE_ACCESSED bitflag here, the TLB miss handler
710 * would be forced to set it later while filling the TLB after we
711 * return to userland. That would trigger a second write to memory
712 * that we optimize away by setting _PAGE_ACCESSED here.
713 */
714#ifndef pte_mknonnuma
715static inline pte_t pte_mknonnuma(pte_t pte)
716{
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717 pteval_t val = pte_val(pte);
718
719 val &= ~_PAGE_NUMA;
720 val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
721 return __pte(val);
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722}
723#endif
724
725#ifndef pmd_mknonnuma
726static inline pmd_t pmd_mknonnuma(pmd_t pmd)
727{
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728 pmdval_t val = pmd_val(pmd);
729
730 val &= ~_PAGE_NUMA;
731 val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
732
733 return __pmd(val);
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734}
735#endif
736
737#ifndef pte_mknuma
738static inline pte_t pte_mknuma(pte_t pte)
739{
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740 pteval_t val = pte_val(pte);
741
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742 VM_BUG_ON(!(val & _PAGE_PRESENT));
743
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744 val &= ~_PAGE_PRESENT;
745 val |= _PAGE_NUMA;
746
747 return __pte(val);
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748}
749#endif
750
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751#ifndef ptep_set_numa
752static inline void ptep_set_numa(struct mm_struct *mm, unsigned long addr,
753 pte_t *ptep)
754{
755 pte_t ptent = *ptep;
756
757 ptent = pte_mknuma(ptent);
758 set_pte_at(mm, addr, ptep, ptent);
759 return;
760}
761#endif
762
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763#ifndef pmd_mknuma
764static inline pmd_t pmd_mknuma(pmd_t pmd)
765{
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766 pmdval_t val = pmd_val(pmd);
767
768 val &= ~_PAGE_PRESENT;
769 val |= _PAGE_NUMA;
770
771 return __pmd(val);
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772}
773#endif
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774
775#ifndef pmdp_set_numa
776static inline void pmdp_set_numa(struct mm_struct *mm, unsigned long addr,
777 pmd_t *pmdp)
778{
779 pmd_t pmd = *pmdp;
780
781 pmd = pmd_mknuma(pmd);
782 set_pmd_at(mm, addr, pmdp, pmd);
783 return;
784}
785#endif
be3a7284 786#else
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787static inline int pmd_numa(pmd_t pmd)
788{
789 return 0;
790}
791
792static inline int pte_numa(pte_t pte)
793{
794 return 0;
795}
796
797static inline pte_t pte_mknonnuma(pte_t pte)
798{
799 return pte;
800}
801
802static inline pmd_t pmd_mknonnuma(pmd_t pmd)
803{
804 return pmd;
805}
806
807static inline pte_t pte_mknuma(pte_t pte)
808{
809 return pte;
810}
811
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812static inline void ptep_set_numa(struct mm_struct *mm, unsigned long addr,
813 pte_t *ptep)
814{
815 return;
816}
817
818
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819static inline pmd_t pmd_mknuma(pmd_t pmd)
820{
821 return pmd;
822}
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823
824static inline void pmdp_set_numa(struct mm_struct *mm, unsigned long addr,
825 pmd_t *pmdp)
826{
827 return ;
828}
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829#endif /* CONFIG_NUMA_BALANCING */
830
1a5a9906 831#endif /* CONFIG_MMU */
5f6e8da7 832
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833#endif /* !__ASSEMBLY__ */
834
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835#ifndef io_remap_pfn_range
836#define io_remap_pfn_range remap_pfn_range
837#endif
838
1da177e4 839#endif /* _ASM_GENERIC_PGTABLE_H */