xref: /linux/arch/arm64/include/asm/pgtable.h (revision f2586d921cea4feeddd1cc5ee3495700540dba8f)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_PGTABLE_H
6 #define __ASM_PGTABLE_H
7 
8 #include <asm/bug.h>
9 #include <asm/proc-fns.h>
10 
11 #include <asm/memory.h>
12 #include <asm/mte.h>
13 #include <asm/pgtable-hwdef.h>
14 #include <asm/pgtable-prot.h>
15 #include <asm/tlbflush.h>
16 
17 /*
18  * VMALLOC range.
19  *
20  * VMALLOC_START: beginning of the kernel vmalloc space
21  * VMALLOC_END: extends to the available space below vmemmap, PCI I/O space
22  *	and fixed mappings
23  */
24 #define VMALLOC_START		(MODULES_END)
25 #define VMALLOC_END		(VMEMMAP_START - SZ_256M)
26 
27 #define vmemmap			((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
28 
29 #ifndef __ASSEMBLY__
30 
31 #include <asm/cmpxchg.h>
32 #include <asm/fixmap.h>
33 #include <linux/mmdebug.h>
34 #include <linux/mm_types.h>
35 #include <linux/sched.h>
36 #include <linux/page_table_check.h>
37 
38 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
39 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
40 
41 /* Set stride and tlb_level in flush_*_tlb_range */
42 #define flush_pmd_tlb_range(vma, addr, end)	\
43 	__flush_tlb_range(vma, addr, end, PMD_SIZE, false, 2)
44 #define flush_pud_tlb_range(vma, addr, end)	\
45 	__flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1)
46 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
47 
48 static inline bool arch_thp_swp_supported(void)
49 {
50 	return !system_supports_mte();
51 }
52 #define arch_thp_swp_supported arch_thp_swp_supported
53 
54 /*
55  * Outside of a few very special situations (e.g. hibernation), we always
56  * use broadcast TLB invalidation instructions, therefore a spurious page
57  * fault on one CPU which has been handled concurrently by another CPU
58  * does not need to perform additional invalidation.
59  */
60 #define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
61 
62 /*
63  * ZERO_PAGE is a global shared page that is always zero: used
64  * for zero-mapped memory areas etc..
65  */
66 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
67 #define ZERO_PAGE(vaddr)	phys_to_page(__pa_symbol(empty_zero_page))
68 
69 #define pte_ERROR(e)	\
70 	pr_err("%s:%d: bad pte %016llx.\n", __FILE__, __LINE__, pte_val(e))
71 
72 /*
73  * Macros to convert between a physical address and its placement in a
74  * page table entry, taking care of 52-bit addresses.
75  */
76 #ifdef CONFIG_ARM64_PA_BITS_52
77 static inline phys_addr_t __pte_to_phys(pte_t pte)
78 {
79 	return (pte_val(pte) & PTE_ADDR_LOW) |
80 		((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT);
81 }
82 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
83 {
84 	return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PTE_ADDR_MASK;
85 }
86 #else
87 #define __pte_to_phys(pte)	(pte_val(pte) & PTE_ADDR_MASK)
88 #define __phys_to_pte_val(phys)	(phys)
89 #endif
90 
91 #define pte_pfn(pte)		(__pte_to_phys(pte) >> PAGE_SHIFT)
92 #define pfn_pte(pfn,prot)	\
93 	__pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
94 
95 #define pte_none(pte)		(!pte_val(pte))
96 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
97 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
98 
99 /*
100  * The following only work if pte_present(). Undefined behaviour otherwise.
101  */
102 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
103 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
104 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
105 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
106 #define pte_rdonly(pte)		(!!(pte_val(pte) & PTE_RDONLY))
107 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
108 #define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
109 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
110 #define pte_devmap(pte)		(!!(pte_val(pte) & PTE_DEVMAP))
111 #define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \
112 				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
113 
114 #define pte_cont_addr_end(addr, end)						\
115 ({	unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;	\
116 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
117 })
118 
119 #define pmd_cont_addr_end(addr, end)						\
120 ({	unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;	\
121 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
122 })
123 
124 #define pte_hw_dirty(pte)	(pte_write(pte) && !pte_rdonly(pte))
125 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
126 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
127 
128 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
129 /*
130  * Execute-only user mappings do not have the PTE_USER bit set. All valid
131  * kernel mappings have the PTE_UXN bit set.
132  */
133 #define pte_valid_not_user(pte) \
134 	((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
135 /*
136  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
137  * so that we don't erroneously return false for pages that have been
138  * remapped as PROT_NONE but are yet to be flushed from the TLB.
139  * Note that we can't make any assumptions based on the state of the access
140  * flag, since ptep_clear_flush_young() elides a DSB when invalidating the
141  * TLB.
142  */
143 #define pte_accessible(mm, pte)	\
144 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
145 
146 /*
147  * p??_access_permitted() is true for valid user mappings (PTE_USER
148  * bit set, subject to the write permission check). For execute-only
149  * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits
150  * not set) must return false. PROT_NONE mappings do not have the
151  * PTE_VALID bit set.
152  */
153 #define pte_access_permitted(pte, write) \
154 	(((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte)))
155 #define pmd_access_permitted(pmd, write) \
156 	(pte_access_permitted(pmd_pte(pmd), (write)))
157 #define pud_access_permitted(pud, write) \
158 	(pte_access_permitted(pud_pte(pud), (write)))
159 
160 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
161 {
162 	pte_val(pte) &= ~pgprot_val(prot);
163 	return pte;
164 }
165 
166 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
167 {
168 	pte_val(pte) |= pgprot_val(prot);
169 	return pte;
170 }
171 
172 static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t prot)
173 {
174 	pmd_val(pmd) &= ~pgprot_val(prot);
175 	return pmd;
176 }
177 
178 static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot)
179 {
180 	pmd_val(pmd) |= pgprot_val(prot);
181 	return pmd;
182 }
183 
184 static inline pte_t pte_mkwrite(pte_t pte)
185 {
186 	pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
187 	pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
188 	return pte;
189 }
190 
191 static inline pte_t pte_mkclean(pte_t pte)
192 {
193 	pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
194 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
195 
196 	return pte;
197 }
198 
199 static inline pte_t pte_mkdirty(pte_t pte)
200 {
201 	pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
202 
203 	if (pte_write(pte))
204 		pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
205 
206 	return pte;
207 }
208 
209 static inline pte_t pte_wrprotect(pte_t pte)
210 {
211 	/*
212 	 * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
213 	 * clear), set the PTE_DIRTY bit.
214 	 */
215 	if (pte_hw_dirty(pte))
216 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
217 
218 	pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
219 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
220 	return pte;
221 }
222 
223 static inline pte_t pte_mkold(pte_t pte)
224 {
225 	return clear_pte_bit(pte, __pgprot(PTE_AF));
226 }
227 
228 static inline pte_t pte_mkyoung(pte_t pte)
229 {
230 	return set_pte_bit(pte, __pgprot(PTE_AF));
231 }
232 
233 static inline pte_t pte_mkspecial(pte_t pte)
234 {
235 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
236 }
237 
238 static inline pte_t pte_mkcont(pte_t pte)
239 {
240 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
241 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
242 }
243 
244 static inline pte_t pte_mknoncont(pte_t pte)
245 {
246 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
247 }
248 
249 static inline pte_t pte_mkpresent(pte_t pte)
250 {
251 	return set_pte_bit(pte, __pgprot(PTE_VALID));
252 }
253 
254 static inline pmd_t pmd_mkcont(pmd_t pmd)
255 {
256 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
257 }
258 
259 static inline pte_t pte_mkdevmap(pte_t pte)
260 {
261 	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));
262 }
263 
264 static inline void set_pte(pte_t *ptep, pte_t pte)
265 {
266 	WRITE_ONCE(*ptep, pte);
267 
268 	/*
269 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
270 	 * or update_mmu_cache() have the necessary barriers.
271 	 */
272 	if (pte_valid_not_user(pte)) {
273 		dsb(ishst);
274 		isb();
275 	}
276 }
277 
278 extern void __sync_icache_dcache(pte_t pteval);
279 bool pgattr_change_is_safe(u64 old, u64 new);
280 
281 /*
282  * PTE bits configuration in the presence of hardware Dirty Bit Management
283  * (PTE_WRITE == PTE_DBM):
284  *
285  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
286  *   0      0      |   1           0          0
287  *   0      1      |   1           1          0
288  *   1      0      |   1           0          1
289  *   1      1      |   0           1          x
290  *
291  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
292  * the page fault mechanism. Checking the dirty status of a pte becomes:
293  *
294  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
295  */
296 
297 static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep,
298 					   pte_t pte)
299 {
300 	pte_t old_pte;
301 
302 	if (!IS_ENABLED(CONFIG_DEBUG_VM))
303 		return;
304 
305 	old_pte = READ_ONCE(*ptep);
306 
307 	if (!pte_valid(old_pte) || !pte_valid(pte))
308 		return;
309 	if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1)
310 		return;
311 
312 	/*
313 	 * Check for potential race with hardware updates of the pte
314 	 * (ptep_set_access_flags safely changes valid ptes without going
315 	 * through an invalid entry).
316 	 */
317 	VM_WARN_ONCE(!pte_young(pte),
318 		     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
319 		     __func__, pte_val(old_pte), pte_val(pte));
320 	VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte),
321 		     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
322 		     __func__, pte_val(old_pte), pte_val(pte));
323 	VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)),
324 		     "%s: unsafe attribute change: 0x%016llx -> 0x%016llx",
325 		     __func__, pte_val(old_pte), pte_val(pte));
326 }
327 
328 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
329 				pte_t *ptep, pte_t pte)
330 {
331 	if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
332 		__sync_icache_dcache(pte);
333 
334 	/*
335 	 * If the PTE would provide user space access to the tags associated
336 	 * with it then ensure that the MTE tags are synchronised.  Although
337 	 * pte_access_permitted() returns false for exec only mappings, they
338 	 * don't expose tags (instruction fetches don't check tags).
339 	 */
340 	if (system_supports_mte() && pte_access_permitted(pte, false) &&
341 	    !pte_special(pte)) {
342 		pte_t old_pte = READ_ONCE(*ptep);
343 		/*
344 		 * We only need to synchronise if the new PTE has tags enabled
345 		 * or if swapping in (in which case another mapping may have
346 		 * set tags in the past even if this PTE isn't tagged).
347 		 * (!pte_none() && !pte_present()) is an open coded version of
348 		 * is_swap_pte()
349 		 */
350 		if (pte_tagged(pte) || (!pte_none(old_pte) && !pte_present(old_pte)))
351 			mte_sync_tags(old_pte, pte);
352 	}
353 
354 	__check_safe_pte_update(mm, ptep, pte);
355 
356 	set_pte(ptep, pte);
357 }
358 
359 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
360 			      pte_t *ptep, pte_t pte)
361 {
362 	page_table_check_pte_set(mm, addr, ptep, pte);
363 	return __set_pte_at(mm, addr, ptep, pte);
364 }
365 
366 /*
367  * Huge pte definitions.
368  */
369 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
370 
371 /*
372  * Hugetlb definitions.
373  */
374 #define HUGE_MAX_HSTATE		4
375 #define HPAGE_SHIFT		PMD_SHIFT
376 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
377 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
378 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
379 
380 static inline pte_t pgd_pte(pgd_t pgd)
381 {
382 	return __pte(pgd_val(pgd));
383 }
384 
385 static inline pte_t p4d_pte(p4d_t p4d)
386 {
387 	return __pte(p4d_val(p4d));
388 }
389 
390 static inline pte_t pud_pte(pud_t pud)
391 {
392 	return __pte(pud_val(pud));
393 }
394 
395 static inline pud_t pte_pud(pte_t pte)
396 {
397 	return __pud(pte_val(pte));
398 }
399 
400 static inline pmd_t pud_pmd(pud_t pud)
401 {
402 	return __pmd(pud_val(pud));
403 }
404 
405 static inline pte_t pmd_pte(pmd_t pmd)
406 {
407 	return __pte(pmd_val(pmd));
408 }
409 
410 static inline pmd_t pte_pmd(pte_t pte)
411 {
412 	return __pmd(pte_val(pte));
413 }
414 
415 static inline pgprot_t mk_pud_sect_prot(pgprot_t prot)
416 {
417 	return __pgprot((pgprot_val(prot) & ~PUD_TABLE_BIT) | PUD_TYPE_SECT);
418 }
419 
420 static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot)
421 {
422 	return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT);
423 }
424 
425 static inline pte_t pte_swp_mkexclusive(pte_t pte)
426 {
427 	return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
428 }
429 
430 static inline int pte_swp_exclusive(pte_t pte)
431 {
432 	return pte_val(pte) & PTE_SWP_EXCLUSIVE;
433 }
434 
435 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
436 {
437 	return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
438 }
439 
440 /*
441  * Select all bits except the pfn
442  */
443 static inline pgprot_t pte_pgprot(pte_t pte)
444 {
445 	unsigned long pfn = pte_pfn(pte);
446 
447 	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
448 }
449 
450 #ifdef CONFIG_NUMA_BALANCING
451 /*
452  * See the comment in include/linux/pgtable.h
453  */
454 static inline int pte_protnone(pte_t pte)
455 {
456 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
457 }
458 
459 static inline int pmd_protnone(pmd_t pmd)
460 {
461 	return pte_protnone(pmd_pte(pmd));
462 }
463 #endif
464 
465 #define pmd_present_invalid(pmd)     (!!(pmd_val(pmd) & PMD_PRESENT_INVALID))
466 
467 static inline int pmd_present(pmd_t pmd)
468 {
469 	return pte_present(pmd_pte(pmd)) || pmd_present_invalid(pmd);
470 }
471 
472 /*
473  * THP definitions.
474  */
475 
476 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
477 static inline int pmd_trans_huge(pmd_t pmd)
478 {
479 	return pmd_val(pmd) && pmd_present(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
480 }
481 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
482 
483 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
484 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
485 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
486 #define pmd_user(pmd)		pte_user(pmd_pte(pmd))
487 #define pmd_user_exec(pmd)	pte_user_exec(pmd_pte(pmd))
488 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
489 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
490 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
491 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
492 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
493 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
494 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
495 
496 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
497 {
498 	pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID));
499 	pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID));
500 
501 	return pmd;
502 }
503 
504 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
505 
506 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
507 
508 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
509 
510 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
511 #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
512 #endif
513 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
514 {
515 	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
516 }
517 
518 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
519 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
520 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
521 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
522 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
523 
524 #define pud_young(pud)		pte_young(pud_pte(pud))
525 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
526 #define pud_write(pud)		pte_write(pud_pte(pud))
527 
528 #define pud_mkhuge(pud)		(__pud(pud_val(pud) & ~PUD_TABLE_BIT))
529 
530 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
531 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
532 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
533 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
534 
535 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
536 			      pmd_t *pmdp, pmd_t pmd)
537 {
538 	page_table_check_pmd_set(mm, addr, pmdp, pmd);
539 	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
540 }
541 
542 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
543 			      pud_t *pudp, pud_t pud)
544 {
545 	page_table_check_pud_set(mm, addr, pudp, pud);
546 	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
547 }
548 
549 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
550 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
551 
552 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
553 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
554 
555 #define __pgprot_modify(prot,mask,bits) \
556 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
557 
558 #define pgprot_nx(prot) \
559 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
560 
561 /*
562  * Mark the prot value as uncacheable and unbufferable.
563  */
564 #define pgprot_noncached(prot) \
565 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
566 #define pgprot_writecombine(prot) \
567 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
568 #define pgprot_device(prot) \
569 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
570 #define pgprot_tagged(prot) \
571 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
572 #define pgprot_mhp	pgprot_tagged
573 /*
574  * DMA allocations for non-coherent devices use what the Arm architecture calls
575  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
576  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
577  * is intended for MMIO and thus forbids speculation, preserves access size,
578  * requires strict alignment and can also force write responses to come from the
579  * endpoint.
580  */
581 #define pgprot_dmacoherent(prot) \
582 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
583 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
584 
585 #define __HAVE_PHYS_MEM_ACCESS_PROT
586 struct file;
587 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
588 				     unsigned long size, pgprot_t vma_prot);
589 
590 #define pmd_none(pmd)		(!pmd_val(pmd))
591 
592 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
593 				 PMD_TYPE_TABLE)
594 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
595 				 PMD_TYPE_SECT)
596 #define pmd_leaf(pmd)		(pmd_present(pmd) && !pmd_table(pmd))
597 #define pmd_bad(pmd)		(!pmd_table(pmd))
598 
599 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
600 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
601 
602 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
603 static inline bool pud_sect(pud_t pud) { return false; }
604 static inline bool pud_table(pud_t pud) { return true; }
605 #else
606 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
607 				 PUD_TYPE_SECT)
608 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
609 				 PUD_TYPE_TABLE)
610 #endif
611 
612 extern pgd_t init_pg_dir[PTRS_PER_PGD];
613 extern pgd_t init_pg_end[];
614 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
615 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
616 extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
617 extern pgd_t reserved_pg_dir[PTRS_PER_PGD];
618 
619 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
620 
621 static inline bool in_swapper_pgdir(void *addr)
622 {
623 	return ((unsigned long)addr & PAGE_MASK) ==
624 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
625 }
626 
627 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
628 {
629 #ifdef __PAGETABLE_PMD_FOLDED
630 	if (in_swapper_pgdir(pmdp)) {
631 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
632 		return;
633 	}
634 #endif /* __PAGETABLE_PMD_FOLDED */
635 
636 	WRITE_ONCE(*pmdp, pmd);
637 
638 	if (pmd_valid(pmd)) {
639 		dsb(ishst);
640 		isb();
641 	}
642 }
643 
644 static inline void pmd_clear(pmd_t *pmdp)
645 {
646 	set_pmd(pmdp, __pmd(0));
647 }
648 
649 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
650 {
651 	return __pmd_to_phys(pmd);
652 }
653 
654 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
655 {
656 	return (unsigned long)__va(pmd_page_paddr(pmd));
657 }
658 
659 /* Find an entry in the third-level page table. */
660 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
661 
662 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
663 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
664 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
665 
666 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
667 
668 /* use ONLY for statically allocated translation tables */
669 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
670 
671 /*
672  * Conversion functions: convert a page and protection to a page entry,
673  * and a page entry and page directory to the page they refer to.
674  */
675 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
676 
677 #if CONFIG_PGTABLE_LEVELS > 2
678 
679 #define pmd_ERROR(e)	\
680 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
681 
682 #define pud_none(pud)		(!pud_val(pud))
683 #define pud_bad(pud)		(!pud_table(pud))
684 #define pud_present(pud)	pte_present(pud_pte(pud))
685 #define pud_leaf(pud)		(pud_present(pud) && !pud_table(pud))
686 #define pud_valid(pud)		pte_valid(pud_pte(pud))
687 #define pud_user(pud)		pte_user(pud_pte(pud))
688 #define pud_user_exec(pud)	pte_user_exec(pud_pte(pud))
689 
690 static inline void set_pud(pud_t *pudp, pud_t pud)
691 {
692 #ifdef __PAGETABLE_PUD_FOLDED
693 	if (in_swapper_pgdir(pudp)) {
694 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
695 		return;
696 	}
697 #endif /* __PAGETABLE_PUD_FOLDED */
698 
699 	WRITE_ONCE(*pudp, pud);
700 
701 	if (pud_valid(pud)) {
702 		dsb(ishst);
703 		isb();
704 	}
705 }
706 
707 static inline void pud_clear(pud_t *pudp)
708 {
709 	set_pud(pudp, __pud(0));
710 }
711 
712 static inline phys_addr_t pud_page_paddr(pud_t pud)
713 {
714 	return __pud_to_phys(pud);
715 }
716 
717 static inline pmd_t *pud_pgtable(pud_t pud)
718 {
719 	return (pmd_t *)__va(pud_page_paddr(pud));
720 }
721 
722 /* Find an entry in the second-level page table. */
723 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
724 
725 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
726 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
727 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
728 
729 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
730 
731 /* use ONLY for statically allocated translation tables */
732 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
733 
734 #else
735 
736 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
737 #define pud_user_exec(pud)	pud_user(pud) /* Always 0 with folding */
738 
739 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
740 #define pmd_set_fixmap(addr)		NULL
741 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
742 #define pmd_clear_fixmap()
743 
744 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
745 
746 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
747 
748 #if CONFIG_PGTABLE_LEVELS > 3
749 
750 #define pud_ERROR(e)	\
751 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
752 
753 #define p4d_none(p4d)		(!p4d_val(p4d))
754 #define p4d_bad(p4d)		(!(p4d_val(p4d) & 2))
755 #define p4d_present(p4d)	(p4d_val(p4d))
756 
757 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
758 {
759 	if (in_swapper_pgdir(p4dp)) {
760 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
761 		return;
762 	}
763 
764 	WRITE_ONCE(*p4dp, p4d);
765 	dsb(ishst);
766 	isb();
767 }
768 
769 static inline void p4d_clear(p4d_t *p4dp)
770 {
771 	set_p4d(p4dp, __p4d(0));
772 }
773 
774 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
775 {
776 	return __p4d_to_phys(p4d);
777 }
778 
779 static inline pud_t *p4d_pgtable(p4d_t p4d)
780 {
781 	return (pud_t *)__va(p4d_page_paddr(p4d));
782 }
783 
784 /* Find an entry in the first-level page table. */
785 #define pud_offset_phys(dir, addr)	(p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t))
786 
787 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
788 #define pud_set_fixmap_offset(p4d, addr)	pud_set_fixmap(pud_offset_phys(p4d, addr))
789 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
790 
791 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
792 
793 /* use ONLY for statically allocated translation tables */
794 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
795 
796 #else
797 
798 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
799 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
800 
801 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
802 #define pud_set_fixmap(addr)		NULL
803 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
804 #define pud_clear_fixmap()
805 
806 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
807 
808 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
809 
810 #define pgd_ERROR(e)	\
811 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
812 
813 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
814 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
815 
816 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
817 {
818 	/*
819 	 * Normal and Normal-Tagged are two different memory types and indices
820 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
821 	 */
822 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
823 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP |
824 			      PTE_ATTRINDX_MASK;
825 	/* preserve the hardware dirty information */
826 	if (pte_hw_dirty(pte))
827 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
828 
829 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
830 	return pte;
831 }
832 
833 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
834 {
835 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
836 }
837 
838 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
839 extern int ptep_set_access_flags(struct vm_area_struct *vma,
840 				 unsigned long address, pte_t *ptep,
841 				 pte_t entry, int dirty);
842 
843 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
844 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
845 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
846 					unsigned long address, pmd_t *pmdp,
847 					pmd_t entry, int dirty)
848 {
849 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
850 }
851 
852 static inline int pud_devmap(pud_t pud)
853 {
854 	return 0;
855 }
856 
857 static inline int pgd_devmap(pgd_t pgd)
858 {
859 	return 0;
860 }
861 #endif
862 
863 #ifdef CONFIG_PAGE_TABLE_CHECK
864 static inline bool pte_user_accessible_page(pte_t pte)
865 {
866 	return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte));
867 }
868 
869 static inline bool pmd_user_accessible_page(pmd_t pmd)
870 {
871 	return pmd_leaf(pmd) && !pmd_present_invalid(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
872 }
873 
874 static inline bool pud_user_accessible_page(pud_t pud)
875 {
876 	return pud_leaf(pud) && (pud_user(pud) || pud_user_exec(pud));
877 }
878 #endif
879 
880 /*
881  * Atomic pte/pmd modifications.
882  */
883 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
884 static inline int __ptep_test_and_clear_young(pte_t *ptep)
885 {
886 	pte_t old_pte, pte;
887 
888 	pte = READ_ONCE(*ptep);
889 	do {
890 		old_pte = pte;
891 		pte = pte_mkold(pte);
892 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
893 					       pte_val(old_pte), pte_val(pte));
894 	} while (pte_val(pte) != pte_val(old_pte));
895 
896 	return pte_young(pte);
897 }
898 
899 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
900 					    unsigned long address,
901 					    pte_t *ptep)
902 {
903 	return __ptep_test_and_clear_young(ptep);
904 }
905 
906 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
907 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
908 					 unsigned long address, pte_t *ptep)
909 {
910 	int young = ptep_test_and_clear_young(vma, address, ptep);
911 
912 	if (young) {
913 		/*
914 		 * We can elide the trailing DSB here since the worst that can
915 		 * happen is that a CPU continues to use the young entry in its
916 		 * TLB and we mistakenly reclaim the associated page. The
917 		 * window for such an event is bounded by the next
918 		 * context-switch, which provides a DSB to complete the TLB
919 		 * invalidation.
920 		 */
921 		flush_tlb_page_nosync(vma, address);
922 	}
923 
924 	return young;
925 }
926 
927 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
928 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
929 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
930 					    unsigned long address,
931 					    pmd_t *pmdp)
932 {
933 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
934 }
935 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
936 
937 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
938 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
939 				       unsigned long address, pte_t *ptep)
940 {
941 	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
942 
943 	page_table_check_pte_clear(mm, address, pte);
944 
945 	return pte;
946 }
947 
948 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
949 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
950 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
951 					    unsigned long address, pmd_t *pmdp)
952 {
953 	pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0));
954 
955 	page_table_check_pmd_clear(mm, address, pmd);
956 
957 	return pmd;
958 }
959 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
960 
961 /*
962  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
963  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
964  */
965 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
966 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
967 {
968 	pte_t old_pte, pte;
969 
970 	pte = READ_ONCE(*ptep);
971 	do {
972 		old_pte = pte;
973 		pte = pte_wrprotect(pte);
974 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
975 					       pte_val(old_pte), pte_val(pte));
976 	} while (pte_val(pte) != pte_val(old_pte));
977 }
978 
979 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
980 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
981 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
982 				      unsigned long address, pmd_t *pmdp)
983 {
984 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
985 }
986 
987 #define pmdp_establish pmdp_establish
988 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
989 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
990 {
991 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
992 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
993 }
994 #endif
995 
996 /*
997  * Encode and decode a swap entry:
998  *	bits 0-1:	present (must be zero)
999  *	bits 2:		remember PG_anon_exclusive
1000  *	bits 3-7:	swap type
1001  *	bits 8-57:	swap offset
1002  *	bit  58:	PTE_PROT_NONE (must be zero)
1003  */
1004 #define __SWP_TYPE_SHIFT	3
1005 #define __SWP_TYPE_BITS		5
1006 #define __SWP_OFFSET_BITS	50
1007 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
1008 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
1009 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
1010 
1011 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1012 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
1013 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
1014 
1015 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1016 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
1017 
1018 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1019 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
1020 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
1021 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
1022 
1023 /*
1024  * Ensure that there are not more swap files than can be encoded in the kernel
1025  * PTEs.
1026  */
1027 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1028 
1029 #ifdef CONFIG_ARM64_MTE
1030 
1031 #define __HAVE_ARCH_PREPARE_TO_SWAP
1032 static inline int arch_prepare_to_swap(struct page *page)
1033 {
1034 	if (system_supports_mte())
1035 		return mte_save_tags(page);
1036 	return 0;
1037 }
1038 
1039 #define __HAVE_ARCH_SWAP_INVALIDATE
1040 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
1041 {
1042 	if (system_supports_mte())
1043 		mte_invalidate_tags(type, offset);
1044 }
1045 
1046 static inline void arch_swap_invalidate_area(int type)
1047 {
1048 	if (system_supports_mte())
1049 		mte_invalidate_tags_area(type);
1050 }
1051 
1052 #define __HAVE_ARCH_SWAP_RESTORE
1053 static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
1054 {
1055 	if (system_supports_mte())
1056 		mte_restore_tags(entry, &folio->page);
1057 }
1058 
1059 #endif /* CONFIG_ARM64_MTE */
1060 
1061 /*
1062  * On AArch64, the cache coherency is handled via the set_pte_at() function.
1063  */
1064 static inline void update_mmu_cache(struct vm_area_struct *vma,
1065 				    unsigned long addr, pte_t *ptep)
1066 {
1067 	/*
1068 	 * We don't do anything here, so there's a very small chance of
1069 	 * us retaking a user fault which we just fixed up. The alternative
1070 	 * is doing a dsb(ishst), but that penalises the fastpath.
1071 	 */
1072 }
1073 
1074 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
1075 
1076 #ifdef CONFIG_ARM64_PA_BITS_52
1077 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
1078 #else
1079 #define phys_to_ttbr(addr)	(addr)
1080 #endif
1081 
1082 /*
1083  * On arm64 without hardware Access Flag, copying from user will fail because
1084  * the pte is old and cannot be marked young. So we always end up with zeroed
1085  * page after fork() + CoW for pfn mappings. We don't always have a
1086  * hardware-managed access flag on arm64.
1087  */
1088 #define arch_has_hw_pte_young		cpu_has_hw_af
1089 
1090 /*
1091  * Experimentally, it's cheap to set the access flag in hardware and we
1092  * benefit from prefaulting mappings as 'old' to start with.
1093  */
1094 #define arch_wants_old_prefaulted_pte	cpu_has_hw_af
1095 
1096 static inline bool pud_sect_supported(void)
1097 {
1098 	return PAGE_SIZE == SZ_4K;
1099 }
1100 
1101 
1102 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1103 #define ptep_modify_prot_start ptep_modify_prot_start
1104 extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
1105 				    unsigned long addr, pte_t *ptep);
1106 
1107 #define ptep_modify_prot_commit ptep_modify_prot_commit
1108 extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
1109 				    unsigned long addr, pte_t *ptep,
1110 				    pte_t old_pte, pte_t new_pte);
1111 #endif /* !__ASSEMBLY__ */
1112 
1113 #endif /* __ASM_PGTABLE_H */
1114