xref: /linux/arch/arm64/include/asm/pgtable.h (revision bf25266f83821697dc5cc3571ff5e079840db027)
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
22  */
23 #define VMALLOC_START		(MODULES_END)
24 #if VA_BITS == VA_BITS_MIN
25 #define VMALLOC_END		(VMEMMAP_START - SZ_8M)
26 #else
27 #define VMEMMAP_UNUSED_NPAGES	((_PAGE_OFFSET(vabits_actual) - PAGE_OFFSET) >> PAGE_SHIFT)
28 #define VMALLOC_END		(VMEMMAP_START + VMEMMAP_UNUSED_NPAGES * sizeof(struct page) - SZ_8M)
29 #endif
30 
31 #define vmemmap			((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
32 
33 #ifndef __ASSEMBLY__
34 
35 #include <asm/cmpxchg.h>
36 #include <asm/fixmap.h>
37 #include <asm/por.h>
38 #include <linux/mmdebug.h>
39 #include <linux/mm_types.h>
40 #include <linux/sched.h>
41 #include <linux/page_table_check.h>
42 
43 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
44 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
45 
46 /* Set stride and tlb_level in flush_*_tlb_range */
47 #define flush_pmd_tlb_range(vma, addr, end)	\
48 	__flush_tlb_range(vma, addr, end, PMD_SIZE, false, 2)
49 #define flush_pud_tlb_range(vma, addr, end)	\
50 	__flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1)
51 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
52 
53 /*
54  * Outside of a few very special situations (e.g. hibernation), we always
55  * use broadcast TLB invalidation instructions, therefore a spurious page
56  * fault on one CPU which has been handled concurrently by another CPU
57  * does not need to perform additional invalidation.
58  */
59 #define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
60 
61 /*
62  * ZERO_PAGE is a global shared page that is always zero: used
63  * for zero-mapped memory areas etc..
64  */
65 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
66 #define ZERO_PAGE(vaddr)	phys_to_page(__pa_symbol(empty_zero_page))
67 
68 #define pte_ERROR(e)	\
69 	pr_err("%s:%d: bad pte %016llx.\n", __FILE__, __LINE__, pte_val(e))
70 
71 #ifdef CONFIG_ARM64_PA_BITS_52
72 static inline phys_addr_t __pte_to_phys(pte_t pte)
73 {
74 	pte_val(pte) &= ~PTE_MAYBE_SHARED;
75 	return (pte_val(pte) & PTE_ADDR_LOW) |
76 		((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT);
77 }
78 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
79 {
80 	return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PHYS_TO_PTE_ADDR_MASK;
81 }
82 #else
83 static inline phys_addr_t __pte_to_phys(pte_t pte)
84 {
85 	return pte_val(pte) & PTE_ADDR_LOW;
86 }
87 
88 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
89 {
90 	return phys;
91 }
92 #endif
93 
94 #define pte_pfn(pte)		(__pte_to_phys(pte) >> PAGE_SHIFT)
95 #define pfn_pte(pfn,prot)	\
96 	__pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
97 
98 #define pte_none(pte)		(!pte_val(pte))
99 #define __pte_clear(mm, addr, ptep) \
100 				__set_pte(ptep, __pte(0))
101 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
102 
103 /*
104  * The following only work if pte_present(). Undefined behaviour otherwise.
105  */
106 #define pte_present(pte)	(pte_valid(pte) || pte_present_invalid(pte))
107 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
108 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
109 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
110 #define pte_rdonly(pte)		(!!(pte_val(pte) & PTE_RDONLY))
111 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
112 #define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
113 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
114 #define pte_devmap(pte)		(!!(pte_val(pte) & PTE_DEVMAP))
115 #define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \
116 				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
117 
118 #define pte_cont_addr_end(addr, end)						\
119 ({	unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;	\
120 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
121 })
122 
123 #define pmd_cont_addr_end(addr, end)						\
124 ({	unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;	\
125 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
126 })
127 
128 #define pte_hw_dirty(pte)	(pte_write(pte) && !pte_rdonly(pte))
129 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
130 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
131 
132 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
133 #define pte_present_invalid(pte) \
134 	((pte_val(pte) & (PTE_VALID | PTE_PRESENT_INVALID)) == PTE_PRESENT_INVALID)
135 /*
136  * Execute-only user mappings do not have the PTE_USER bit set. All valid
137  * kernel mappings have the PTE_UXN bit set.
138  */
139 #define pte_valid_not_user(pte) \
140 	((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
141 /*
142  * Returns true if the pte is valid and has the contiguous bit set.
143  */
144 #define pte_valid_cont(pte)	(pte_valid(pte) && pte_cont(pte))
145 /*
146  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
147  * so that we don't erroneously return false for pages that have been
148  * remapped as PROT_NONE but are yet to be flushed from the TLB.
149  * Note that we can't make any assumptions based on the state of the access
150  * flag, since __ptep_clear_flush_young() elides a DSB when invalidating the
151  * TLB.
152  */
153 #define pte_accessible(mm, pte)	\
154 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
155 
156 static inline bool por_el0_allows_pkey(u8 pkey, bool write, bool execute)
157 {
158 	u64 por;
159 
160 	if (!system_supports_poe())
161 		return true;
162 
163 	por = read_sysreg_s(SYS_POR_EL0);
164 
165 	if (write)
166 		return por_elx_allows_write(por, pkey);
167 
168 	if (execute)
169 		return por_elx_allows_exec(por, pkey);
170 
171 	return por_elx_allows_read(por, pkey);
172 }
173 
174 /*
175  * p??_access_permitted() is true for valid user mappings (PTE_USER
176  * bit set, subject to the write permission check). For execute-only
177  * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits
178  * not set) must return false. PROT_NONE mappings do not have the
179  * PTE_VALID bit set.
180  */
181 #define pte_access_permitted_no_overlay(pte, write) \
182 	(((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte)))
183 #define pte_access_permitted(pte, write) \
184 	(pte_access_permitted_no_overlay(pte, write) && \
185 	por_el0_allows_pkey(FIELD_GET(PTE_PO_IDX_MASK, pte_val(pte)), write, false))
186 #define pmd_access_permitted(pmd, write) \
187 	(pte_access_permitted(pmd_pte(pmd), (write)))
188 #define pud_access_permitted(pud, write) \
189 	(pte_access_permitted(pud_pte(pud), (write)))
190 
191 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
192 {
193 	pte_val(pte) &= ~pgprot_val(prot);
194 	return pte;
195 }
196 
197 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
198 {
199 	pte_val(pte) |= pgprot_val(prot);
200 	return pte;
201 }
202 
203 static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t prot)
204 {
205 	pmd_val(pmd) &= ~pgprot_val(prot);
206 	return pmd;
207 }
208 
209 static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot)
210 {
211 	pmd_val(pmd) |= pgprot_val(prot);
212 	return pmd;
213 }
214 
215 static inline pte_t pte_mkwrite_novma(pte_t pte)
216 {
217 	pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
218 	pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
219 	return pte;
220 }
221 
222 static inline pte_t pte_mkclean(pte_t pte)
223 {
224 	pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
225 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
226 
227 	return pte;
228 }
229 
230 static inline pte_t pte_mkdirty(pte_t pte)
231 {
232 	pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
233 
234 	if (pte_write(pte))
235 		pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
236 
237 	return pte;
238 }
239 
240 static inline pte_t pte_wrprotect(pte_t pte)
241 {
242 	/*
243 	 * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
244 	 * clear), set the PTE_DIRTY bit.
245 	 */
246 	if (pte_hw_dirty(pte))
247 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
248 
249 	pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
250 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
251 	return pte;
252 }
253 
254 static inline pte_t pte_mkold(pte_t pte)
255 {
256 	return clear_pte_bit(pte, __pgprot(PTE_AF));
257 }
258 
259 static inline pte_t pte_mkyoung(pte_t pte)
260 {
261 	return set_pte_bit(pte, __pgprot(PTE_AF));
262 }
263 
264 static inline pte_t pte_mkspecial(pte_t pte)
265 {
266 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
267 }
268 
269 static inline pte_t pte_mkcont(pte_t pte)
270 {
271 	return set_pte_bit(pte, __pgprot(PTE_CONT));
272 }
273 
274 static inline pte_t pte_mknoncont(pte_t pte)
275 {
276 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
277 }
278 
279 static inline pte_t pte_mkvalid(pte_t pte)
280 {
281 	return set_pte_bit(pte, __pgprot(PTE_VALID));
282 }
283 
284 static inline pte_t pte_mkinvalid(pte_t pte)
285 {
286 	pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID));
287 	pte = clear_pte_bit(pte, __pgprot(PTE_VALID));
288 	return pte;
289 }
290 
291 static inline pmd_t pmd_mkcont(pmd_t pmd)
292 {
293 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
294 }
295 
296 static inline pte_t pte_mkdevmap(pte_t pte)
297 {
298 	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));
299 }
300 
301 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
302 static inline int pte_uffd_wp(pte_t pte)
303 {
304 	return !!(pte_val(pte) & PTE_UFFD_WP);
305 }
306 
307 static inline pte_t pte_mkuffd_wp(pte_t pte)
308 {
309 	return pte_wrprotect(set_pte_bit(pte, __pgprot(PTE_UFFD_WP)));
310 }
311 
312 static inline pte_t pte_clear_uffd_wp(pte_t pte)
313 {
314 	return clear_pte_bit(pte, __pgprot(PTE_UFFD_WP));
315 }
316 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
317 
318 static inline void __set_pte_nosync(pte_t *ptep, pte_t pte)
319 {
320 	WRITE_ONCE(*ptep, pte);
321 }
322 
323 static inline void __set_pte(pte_t *ptep, pte_t pte)
324 {
325 	__set_pte_nosync(ptep, pte);
326 
327 	/*
328 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
329 	 * or update_mmu_cache() have the necessary barriers.
330 	 */
331 	if (pte_valid_not_user(pte)) {
332 		dsb(ishst);
333 		isb();
334 	}
335 }
336 
337 static inline pte_t __ptep_get(pte_t *ptep)
338 {
339 	return READ_ONCE(*ptep);
340 }
341 
342 extern void __sync_icache_dcache(pte_t pteval);
343 bool pgattr_change_is_safe(pteval_t old, pteval_t new);
344 
345 /*
346  * PTE bits configuration in the presence of hardware Dirty Bit Management
347  * (PTE_WRITE == PTE_DBM):
348  *
349  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
350  *   0      0      |   1           0          0
351  *   0      1      |   1           1          0
352  *   1      0      |   1           0          1
353  *   1      1      |   0           1          x
354  *
355  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
356  * the page fault mechanism. Checking the dirty status of a pte becomes:
357  *
358  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
359  */
360 
361 static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep,
362 					   pte_t pte)
363 {
364 	pte_t old_pte;
365 
366 	if (!IS_ENABLED(CONFIG_DEBUG_VM))
367 		return;
368 
369 	old_pte = __ptep_get(ptep);
370 
371 	if (!pte_valid(old_pte) || !pte_valid(pte))
372 		return;
373 	if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1)
374 		return;
375 
376 	/*
377 	 * Check for potential race with hardware updates of the pte
378 	 * (__ptep_set_access_flags safely changes valid ptes without going
379 	 * through an invalid entry).
380 	 */
381 	VM_WARN_ONCE(!pte_young(pte),
382 		     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
383 		     __func__, pte_val(old_pte), pte_val(pte));
384 	VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte),
385 		     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
386 		     __func__, pte_val(old_pte), pte_val(pte));
387 	VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)),
388 		     "%s: unsafe attribute change: 0x%016llx -> 0x%016llx",
389 		     __func__, pte_val(old_pte), pte_val(pte));
390 }
391 
392 static inline void __sync_cache_and_tags(pte_t pte, unsigned int nr_pages)
393 {
394 	if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
395 		__sync_icache_dcache(pte);
396 
397 	/*
398 	 * If the PTE would provide user space access to the tags associated
399 	 * with it then ensure that the MTE tags are synchronised.  Although
400 	 * pte_access_permitted_no_overlay() returns false for exec only
401 	 * mappings, they don't expose tags (instruction fetches don't check
402 	 * tags).
403 	 */
404 	if (system_supports_mte() && pte_access_permitted_no_overlay(pte, false) &&
405 	    !pte_special(pte) && pte_tagged(pte))
406 		mte_sync_tags(pte, nr_pages);
407 }
408 
409 /*
410  * Select all bits except the pfn
411  */
412 #define pte_pgprot pte_pgprot
413 static inline pgprot_t pte_pgprot(pte_t pte)
414 {
415 	unsigned long pfn = pte_pfn(pte);
416 
417 	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
418 }
419 
420 #define pte_advance_pfn pte_advance_pfn
421 static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr)
422 {
423 	return pfn_pte(pte_pfn(pte) + nr, pte_pgprot(pte));
424 }
425 
426 static inline void __set_ptes(struct mm_struct *mm,
427 			      unsigned long __always_unused addr,
428 			      pte_t *ptep, pte_t pte, unsigned int nr)
429 {
430 	page_table_check_ptes_set(mm, ptep, pte, nr);
431 	__sync_cache_and_tags(pte, nr);
432 
433 	for (;;) {
434 		__check_safe_pte_update(mm, ptep, pte);
435 		__set_pte(ptep, pte);
436 		if (--nr == 0)
437 			break;
438 		ptep++;
439 		pte = pte_advance_pfn(pte, 1);
440 	}
441 }
442 
443 /*
444  * Hugetlb definitions.
445  */
446 #define HUGE_MAX_HSTATE		4
447 #define HPAGE_SHIFT		PMD_SHIFT
448 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
449 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
450 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
451 
452 static inline pte_t pgd_pte(pgd_t pgd)
453 {
454 	return __pte(pgd_val(pgd));
455 }
456 
457 static inline pte_t p4d_pte(p4d_t p4d)
458 {
459 	return __pte(p4d_val(p4d));
460 }
461 
462 static inline pte_t pud_pte(pud_t pud)
463 {
464 	return __pte(pud_val(pud));
465 }
466 
467 static inline pud_t pte_pud(pte_t pte)
468 {
469 	return __pud(pte_val(pte));
470 }
471 
472 static inline pmd_t pud_pmd(pud_t pud)
473 {
474 	return __pmd(pud_val(pud));
475 }
476 
477 static inline pte_t pmd_pte(pmd_t pmd)
478 {
479 	return __pte(pmd_val(pmd));
480 }
481 
482 static inline pmd_t pte_pmd(pte_t pte)
483 {
484 	return __pmd(pte_val(pte));
485 }
486 
487 static inline pgprot_t mk_pud_sect_prot(pgprot_t prot)
488 {
489 	return __pgprot((pgprot_val(prot) & ~PUD_TABLE_BIT) | PUD_TYPE_SECT);
490 }
491 
492 static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot)
493 {
494 	return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT);
495 }
496 
497 static inline pte_t pte_swp_mkexclusive(pte_t pte)
498 {
499 	return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
500 }
501 
502 static inline int pte_swp_exclusive(pte_t pte)
503 {
504 	return pte_val(pte) & PTE_SWP_EXCLUSIVE;
505 }
506 
507 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
508 {
509 	return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
510 }
511 
512 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
513 static inline pte_t pte_swp_mkuffd_wp(pte_t pte)
514 {
515 	return set_pte_bit(pte, __pgprot(PTE_SWP_UFFD_WP));
516 }
517 
518 static inline int pte_swp_uffd_wp(pte_t pte)
519 {
520 	return !!(pte_val(pte) & PTE_SWP_UFFD_WP);
521 }
522 
523 static inline pte_t pte_swp_clear_uffd_wp(pte_t pte)
524 {
525 	return clear_pte_bit(pte, __pgprot(PTE_SWP_UFFD_WP));
526 }
527 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
528 
529 #ifdef CONFIG_NUMA_BALANCING
530 /*
531  * See the comment in include/linux/pgtable.h
532  */
533 static inline int pte_protnone(pte_t pte)
534 {
535 	/*
536 	 * pte_present_invalid() tells us that the pte is invalid from HW
537 	 * perspective but present from SW perspective, so the fields are to be
538 	 * interpretted as per the HW layout. The second 2 checks are the unique
539 	 * encoding that we use for PROT_NONE. It is insufficient to only use
540 	 * the first check because we share the same encoding scheme with pmds
541 	 * which support pmd_mkinvalid(), so can be present-invalid without
542 	 * being PROT_NONE.
543 	 */
544 	return pte_present_invalid(pte) && !pte_user(pte) && !pte_user_exec(pte);
545 }
546 
547 static inline int pmd_protnone(pmd_t pmd)
548 {
549 	return pte_protnone(pmd_pte(pmd));
550 }
551 #endif
552 
553 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
554 
555 /*
556  * THP definitions.
557  */
558 
559 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
560 static inline int pmd_trans_huge(pmd_t pmd)
561 {
562 	return pmd_val(pmd) && pmd_present(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
563 }
564 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
565 
566 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
567 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
568 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
569 #define pmd_user(pmd)		pte_user(pmd_pte(pmd))
570 #define pmd_user_exec(pmd)	pte_user_exec(pmd_pte(pmd))
571 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
572 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
573 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
574 #define pmd_mkwrite_novma(pmd)	pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)))
575 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
576 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
577 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
578 #define pmd_mkinvalid(pmd)	pte_pmd(pte_mkinvalid(pmd_pte(pmd)))
579 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
580 #define pmd_uffd_wp(pmd)	pte_uffd_wp(pmd_pte(pmd))
581 #define pmd_mkuffd_wp(pmd)	pte_pmd(pte_mkuffd_wp(pmd_pte(pmd)))
582 #define pmd_clear_uffd_wp(pmd)	pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd)))
583 #define pmd_swp_uffd_wp(pmd)	pte_swp_uffd_wp(pmd_pte(pmd))
584 #define pmd_swp_mkuffd_wp(pmd)	pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd)))
585 #define pmd_swp_clear_uffd_wp(pmd) \
586 				pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd)))
587 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
588 
589 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
590 
591 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
592 
593 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
594 #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
595 #endif
596 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
597 {
598 	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
599 }
600 
601 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
602 #define pmd_special(pte)	(!!((pmd_val(pte) & PTE_SPECIAL)))
603 static inline pmd_t pmd_mkspecial(pmd_t pmd)
604 {
605 	return set_pmd_bit(pmd, __pgprot(PTE_SPECIAL));
606 }
607 #endif
608 
609 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
610 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
611 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
612 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
613 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
614 
615 #define pud_young(pud)		pte_young(pud_pte(pud))
616 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
617 #define pud_write(pud)		pte_write(pud_pte(pud))
618 
619 #define pud_mkhuge(pud)		(__pud(pud_val(pud) & ~PUD_TABLE_BIT))
620 
621 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
622 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
623 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
624 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
625 
626 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
627 #define pud_special(pte)	pte_special(pud_pte(pud))
628 #define pud_mkspecial(pte)	pte_pud(pte_mkspecial(pud_pte(pud)))
629 #endif
630 
631 #define pmd_pgprot pmd_pgprot
632 static inline pgprot_t pmd_pgprot(pmd_t pmd)
633 {
634 	unsigned long pfn = pmd_pfn(pmd);
635 
636 	return __pgprot(pmd_val(pfn_pmd(pfn, __pgprot(0))) ^ pmd_val(pmd));
637 }
638 
639 #define pud_pgprot pud_pgprot
640 static inline pgprot_t pud_pgprot(pud_t pud)
641 {
642 	unsigned long pfn = pud_pfn(pud);
643 
644 	return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud));
645 }
646 
647 static inline void __set_pte_at(struct mm_struct *mm,
648 				unsigned long __always_unused addr,
649 				pte_t *ptep, pte_t pte, unsigned int nr)
650 {
651 	__sync_cache_and_tags(pte, nr);
652 	__check_safe_pte_update(mm, ptep, pte);
653 	__set_pte(ptep, pte);
654 }
655 
656 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
657 			      pmd_t *pmdp, pmd_t pmd)
658 {
659 	page_table_check_pmd_set(mm, pmdp, pmd);
660 	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd),
661 						PMD_SIZE >> PAGE_SHIFT);
662 }
663 
664 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
665 			      pud_t *pudp, pud_t pud)
666 {
667 	page_table_check_pud_set(mm, pudp, pud);
668 	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud),
669 						PUD_SIZE >> PAGE_SHIFT);
670 }
671 
672 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
673 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
674 
675 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
676 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
677 
678 #define __pgprot_modify(prot,mask,bits) \
679 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
680 
681 #define pgprot_nx(prot) \
682 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
683 
684 #define pgprot_decrypted(prot) \
685 	__pgprot_modify(prot, PROT_NS_SHARED, PROT_NS_SHARED)
686 #define pgprot_encrypted(prot) \
687 	__pgprot_modify(prot, PROT_NS_SHARED, 0)
688 
689 /*
690  * Mark the prot value as uncacheable and unbufferable.
691  */
692 #define pgprot_noncached(prot) \
693 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
694 #define pgprot_writecombine(prot) \
695 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
696 #define pgprot_device(prot) \
697 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
698 #define pgprot_tagged(prot) \
699 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
700 #define pgprot_mhp	pgprot_tagged
701 /*
702  * DMA allocations for non-coherent devices use what the Arm architecture calls
703  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
704  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
705  * is intended for MMIO and thus forbids speculation, preserves access size,
706  * requires strict alignment and can also force write responses to come from the
707  * endpoint.
708  */
709 #define pgprot_dmacoherent(prot) \
710 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
711 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
712 
713 #define __HAVE_PHYS_MEM_ACCESS_PROT
714 struct file;
715 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
716 				     unsigned long size, pgprot_t vma_prot);
717 
718 #define pmd_none(pmd)		(!pmd_val(pmd))
719 
720 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
721 				 PMD_TYPE_TABLE)
722 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
723 				 PMD_TYPE_SECT)
724 #define pmd_leaf(pmd)		(pmd_present(pmd) && !pmd_table(pmd))
725 #define pmd_bad(pmd)		(!pmd_table(pmd))
726 
727 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
728 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
729 
730 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
731 static inline bool pud_sect(pud_t pud) { return false; }
732 static inline bool pud_table(pud_t pud) { return true; }
733 #else
734 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
735 				 PUD_TYPE_SECT)
736 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
737 				 PUD_TYPE_TABLE)
738 #endif
739 
740 extern pgd_t init_pg_dir[];
741 extern pgd_t init_pg_end[];
742 extern pgd_t swapper_pg_dir[];
743 extern pgd_t idmap_pg_dir[];
744 extern pgd_t tramp_pg_dir[];
745 extern pgd_t reserved_pg_dir[];
746 
747 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
748 
749 static inline bool in_swapper_pgdir(void *addr)
750 {
751 	return ((unsigned long)addr & PAGE_MASK) ==
752 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
753 }
754 
755 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
756 {
757 #ifdef __PAGETABLE_PMD_FOLDED
758 	if (in_swapper_pgdir(pmdp)) {
759 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
760 		return;
761 	}
762 #endif /* __PAGETABLE_PMD_FOLDED */
763 
764 	WRITE_ONCE(*pmdp, pmd);
765 
766 	if (pmd_valid(pmd)) {
767 		dsb(ishst);
768 		isb();
769 	}
770 }
771 
772 static inline void pmd_clear(pmd_t *pmdp)
773 {
774 	set_pmd(pmdp, __pmd(0));
775 }
776 
777 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
778 {
779 	return __pmd_to_phys(pmd);
780 }
781 
782 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
783 {
784 	return (unsigned long)__va(pmd_page_paddr(pmd));
785 }
786 
787 /* Find an entry in the third-level page table. */
788 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
789 
790 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
791 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
792 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
793 
794 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
795 
796 /* use ONLY for statically allocated translation tables */
797 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
798 
799 /*
800  * Conversion functions: convert a page and protection to a page entry,
801  * and a page entry and page directory to the page they refer to.
802  */
803 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
804 
805 #if CONFIG_PGTABLE_LEVELS > 2
806 
807 #define pmd_ERROR(e)	\
808 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
809 
810 #define pud_none(pud)		(!pud_val(pud))
811 #define pud_bad(pud)		(!pud_table(pud))
812 #define pud_present(pud)	pte_present(pud_pte(pud))
813 #ifndef __PAGETABLE_PMD_FOLDED
814 #define pud_leaf(pud)		(pud_present(pud) && !pud_table(pud))
815 #else
816 #define pud_leaf(pud)		false
817 #endif
818 #define pud_valid(pud)		pte_valid(pud_pte(pud))
819 #define pud_user(pud)		pte_user(pud_pte(pud))
820 #define pud_user_exec(pud)	pte_user_exec(pud_pte(pud))
821 
822 static inline bool pgtable_l4_enabled(void);
823 
824 static inline void set_pud(pud_t *pudp, pud_t pud)
825 {
826 	if (!pgtable_l4_enabled() && in_swapper_pgdir(pudp)) {
827 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
828 		return;
829 	}
830 
831 	WRITE_ONCE(*pudp, pud);
832 
833 	if (pud_valid(pud)) {
834 		dsb(ishst);
835 		isb();
836 	}
837 }
838 
839 static inline void pud_clear(pud_t *pudp)
840 {
841 	set_pud(pudp, __pud(0));
842 }
843 
844 static inline phys_addr_t pud_page_paddr(pud_t pud)
845 {
846 	return __pud_to_phys(pud);
847 }
848 
849 static inline pmd_t *pud_pgtable(pud_t pud)
850 {
851 	return (pmd_t *)__va(pud_page_paddr(pud));
852 }
853 
854 /* Find an entry in the second-level page table. */
855 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
856 
857 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
858 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
859 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
860 
861 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
862 
863 /* use ONLY for statically allocated translation tables */
864 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
865 
866 #else
867 
868 #define pud_valid(pud)		false
869 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
870 #define pud_user_exec(pud)	pud_user(pud) /* Always 0 with folding */
871 
872 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
873 #define pmd_set_fixmap(addr)		NULL
874 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
875 #define pmd_clear_fixmap()
876 
877 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
878 
879 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
880 
881 #if CONFIG_PGTABLE_LEVELS > 3
882 
883 static __always_inline bool pgtable_l4_enabled(void)
884 {
885 	if (CONFIG_PGTABLE_LEVELS > 4 || !IS_ENABLED(CONFIG_ARM64_LPA2))
886 		return true;
887 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
888 		return vabits_actual == VA_BITS;
889 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
890 }
891 
892 static inline bool mm_pud_folded(const struct mm_struct *mm)
893 {
894 	return !pgtable_l4_enabled();
895 }
896 #define mm_pud_folded  mm_pud_folded
897 
898 #define pud_ERROR(e)	\
899 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
900 
901 #define p4d_none(p4d)		(pgtable_l4_enabled() && !p4d_val(p4d))
902 #define p4d_bad(p4d)		(pgtable_l4_enabled() && !(p4d_val(p4d) & P4D_TABLE_BIT))
903 #define p4d_present(p4d)	(!p4d_none(p4d))
904 
905 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
906 {
907 	if (in_swapper_pgdir(p4dp)) {
908 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
909 		return;
910 	}
911 
912 	WRITE_ONCE(*p4dp, p4d);
913 	dsb(ishst);
914 	isb();
915 }
916 
917 static inline void p4d_clear(p4d_t *p4dp)
918 {
919 	if (pgtable_l4_enabled())
920 		set_p4d(p4dp, __p4d(0));
921 }
922 
923 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
924 {
925 	return __p4d_to_phys(p4d);
926 }
927 
928 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
929 
930 static inline pud_t *p4d_to_folded_pud(p4d_t *p4dp, unsigned long addr)
931 {
932 	/* Ensure that 'p4dp' indexes a page table according to 'addr' */
933 	VM_BUG_ON(((addr >> P4D_SHIFT) ^ ((u64)p4dp >> 3)) % PTRS_PER_P4D);
934 
935 	return (pud_t *)PTR_ALIGN_DOWN(p4dp, PAGE_SIZE) + pud_index(addr);
936 }
937 
938 static inline pud_t *p4d_pgtable(p4d_t p4d)
939 {
940 	return (pud_t *)__va(p4d_page_paddr(p4d));
941 }
942 
943 static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr)
944 {
945 	BUG_ON(!pgtable_l4_enabled());
946 
947 	return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t);
948 }
949 
950 static inline
951 pud_t *pud_offset_lockless(p4d_t *p4dp, p4d_t p4d, unsigned long addr)
952 {
953 	if (!pgtable_l4_enabled())
954 		return p4d_to_folded_pud(p4dp, addr);
955 	return (pud_t *)__va(p4d_page_paddr(p4d)) + pud_index(addr);
956 }
957 #define pud_offset_lockless pud_offset_lockless
958 
959 static inline pud_t *pud_offset(p4d_t *p4dp, unsigned long addr)
960 {
961 	return pud_offset_lockless(p4dp, READ_ONCE(*p4dp), addr);
962 }
963 #define pud_offset	pud_offset
964 
965 static inline pud_t *pud_set_fixmap(unsigned long addr)
966 {
967 	if (!pgtable_l4_enabled())
968 		return NULL;
969 	return (pud_t *)set_fixmap_offset(FIX_PUD, addr);
970 }
971 
972 static inline pud_t *pud_set_fixmap_offset(p4d_t *p4dp, unsigned long addr)
973 {
974 	if (!pgtable_l4_enabled())
975 		return p4d_to_folded_pud(p4dp, addr);
976 	return pud_set_fixmap(pud_offset_phys(p4dp, addr));
977 }
978 
979 static inline void pud_clear_fixmap(void)
980 {
981 	if (pgtable_l4_enabled())
982 		clear_fixmap(FIX_PUD);
983 }
984 
985 /* use ONLY for statically allocated translation tables */
986 static inline pud_t *pud_offset_kimg(p4d_t *p4dp, u64 addr)
987 {
988 	if (!pgtable_l4_enabled())
989 		return p4d_to_folded_pud(p4dp, addr);
990 	return (pud_t *)__phys_to_kimg(pud_offset_phys(p4dp, addr));
991 }
992 
993 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
994 
995 #else
996 
997 static inline bool pgtable_l4_enabled(void) { return false; }
998 
999 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
1000 
1001 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
1002 #define pud_set_fixmap(addr)		NULL
1003 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
1004 #define pud_clear_fixmap()
1005 
1006 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
1007 
1008 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
1009 
1010 #if CONFIG_PGTABLE_LEVELS > 4
1011 
1012 static __always_inline bool pgtable_l5_enabled(void)
1013 {
1014 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
1015 		return vabits_actual == VA_BITS;
1016 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
1017 }
1018 
1019 static inline bool mm_p4d_folded(const struct mm_struct *mm)
1020 {
1021 	return !pgtable_l5_enabled();
1022 }
1023 #define mm_p4d_folded  mm_p4d_folded
1024 
1025 #define p4d_ERROR(e)	\
1026 	pr_err("%s:%d: bad p4d %016llx.\n", __FILE__, __LINE__, p4d_val(e))
1027 
1028 #define pgd_none(pgd)		(pgtable_l5_enabled() && !pgd_val(pgd))
1029 #define pgd_bad(pgd)		(pgtable_l5_enabled() && !(pgd_val(pgd) & PGD_TABLE_BIT))
1030 #define pgd_present(pgd)	(!pgd_none(pgd))
1031 
1032 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
1033 {
1034 	if (in_swapper_pgdir(pgdp)) {
1035 		set_swapper_pgd(pgdp, __pgd(pgd_val(pgd)));
1036 		return;
1037 	}
1038 
1039 	WRITE_ONCE(*pgdp, pgd);
1040 	dsb(ishst);
1041 	isb();
1042 }
1043 
1044 static inline void pgd_clear(pgd_t *pgdp)
1045 {
1046 	if (pgtable_l5_enabled())
1047 		set_pgd(pgdp, __pgd(0));
1048 }
1049 
1050 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
1051 {
1052 	return __pgd_to_phys(pgd);
1053 }
1054 
1055 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1056 
1057 static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr)
1058 {
1059 	/* Ensure that 'pgdp' indexes a page table according to 'addr' */
1060 	VM_BUG_ON(((addr >> PGDIR_SHIFT) ^ ((u64)pgdp >> 3)) % PTRS_PER_PGD);
1061 
1062 	return (p4d_t *)PTR_ALIGN_DOWN(pgdp, PAGE_SIZE) + p4d_index(addr);
1063 }
1064 
1065 static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr)
1066 {
1067 	BUG_ON(!pgtable_l5_enabled());
1068 
1069 	return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t);
1070 }
1071 
1072 static inline
1073 p4d_t *p4d_offset_lockless(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1074 {
1075 	if (!pgtable_l5_enabled())
1076 		return pgd_to_folded_p4d(pgdp, addr);
1077 	return (p4d_t *)__va(pgd_page_paddr(pgd)) + p4d_index(addr);
1078 }
1079 #define p4d_offset_lockless p4d_offset_lockless
1080 
1081 static inline p4d_t *p4d_offset(pgd_t *pgdp, unsigned long addr)
1082 {
1083 	return p4d_offset_lockless(pgdp, READ_ONCE(*pgdp), addr);
1084 }
1085 
1086 static inline p4d_t *p4d_set_fixmap(unsigned long addr)
1087 {
1088 	if (!pgtable_l5_enabled())
1089 		return NULL;
1090 	return (p4d_t *)set_fixmap_offset(FIX_P4D, addr);
1091 }
1092 
1093 static inline p4d_t *p4d_set_fixmap_offset(pgd_t *pgdp, unsigned long addr)
1094 {
1095 	if (!pgtable_l5_enabled())
1096 		return pgd_to_folded_p4d(pgdp, addr);
1097 	return p4d_set_fixmap(p4d_offset_phys(pgdp, addr));
1098 }
1099 
1100 static inline void p4d_clear_fixmap(void)
1101 {
1102 	if (pgtable_l5_enabled())
1103 		clear_fixmap(FIX_P4D);
1104 }
1105 
1106 /* use ONLY for statically allocated translation tables */
1107 static inline p4d_t *p4d_offset_kimg(pgd_t *pgdp, u64 addr)
1108 {
1109 	if (!pgtable_l5_enabled())
1110 		return pgd_to_folded_p4d(pgdp, addr);
1111 	return (p4d_t *)__phys_to_kimg(p4d_offset_phys(pgdp, addr));
1112 }
1113 
1114 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(__pgd_to_phys(pgd)))
1115 
1116 #else
1117 
1118 static inline bool pgtable_l5_enabled(void) { return false; }
1119 
1120 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1121 
1122 /* Match p4d_offset folding in <asm/generic/pgtable-nop4d.h> */
1123 #define p4d_set_fixmap(addr)		NULL
1124 #define p4d_set_fixmap_offset(p4dp, addr)	((p4d_t *)p4dp)
1125 #define p4d_clear_fixmap()
1126 
1127 #define p4d_offset_kimg(dir,addr)	((p4d_t *)dir)
1128 
1129 static inline
1130 p4d_t *p4d_offset_lockless_folded(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1131 {
1132 	/*
1133 	 * With runtime folding of the pud, pud_offset_lockless() passes
1134 	 * the 'pgd_t *' we return here to p4d_to_folded_pud(), which
1135 	 * will offset the pointer assuming that it points into
1136 	 * a page-table page. However, the fast GUP path passes us a
1137 	 * pgd_t allocated on the stack and so we must use the original
1138 	 * pointer in 'pgdp' to construct the p4d pointer instead of
1139 	 * using the generic p4d_offset_lockless() implementation.
1140 	 *
1141 	 * Note: reusing the original pointer means that we may
1142 	 * dereference the same (live) page-table entry multiple times.
1143 	 * This is safe because it is still only loaded once in the
1144 	 * context of each level and the CPU guarantees same-address
1145 	 * read-after-read ordering.
1146 	 */
1147 	return p4d_offset(pgdp, addr);
1148 }
1149 #define p4d_offset_lockless p4d_offset_lockless_folded
1150 
1151 #endif  /* CONFIG_PGTABLE_LEVELS > 4 */
1152 
1153 #define pgd_ERROR(e)	\
1154 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
1155 
1156 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
1157 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
1158 
1159 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
1160 {
1161 	/*
1162 	 * Normal and Normal-Tagged are two different memory types and indices
1163 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
1164 	 */
1165 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
1166 			      PTE_PRESENT_INVALID | PTE_VALID | PTE_WRITE |
1167 			      PTE_GP | PTE_ATTRINDX_MASK | PTE_PO_IDX_MASK;
1168 
1169 	/* preserve the hardware dirty information */
1170 	if (pte_hw_dirty(pte))
1171 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
1172 
1173 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
1174 	/*
1175 	 * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware
1176 	 * dirtiness again.
1177 	 */
1178 	if (pte_sw_dirty(pte))
1179 		pte = pte_mkdirty(pte);
1180 	return pte;
1181 }
1182 
1183 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1184 {
1185 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
1186 }
1187 
1188 extern int __ptep_set_access_flags(struct vm_area_struct *vma,
1189 				 unsigned long address, pte_t *ptep,
1190 				 pte_t entry, int dirty);
1191 
1192 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1193 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1194 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1195 					unsigned long address, pmd_t *pmdp,
1196 					pmd_t entry, int dirty)
1197 {
1198 	return __ptep_set_access_flags(vma, address, (pte_t *)pmdp,
1199 							pmd_pte(entry), dirty);
1200 }
1201 
1202 static inline int pud_devmap(pud_t pud)
1203 {
1204 	return 0;
1205 }
1206 
1207 static inline int pgd_devmap(pgd_t pgd)
1208 {
1209 	return 0;
1210 }
1211 #endif
1212 
1213 #ifdef CONFIG_PAGE_TABLE_CHECK
1214 static inline bool pte_user_accessible_page(pte_t pte)
1215 {
1216 	return pte_valid(pte) && (pte_user(pte) || pte_user_exec(pte));
1217 }
1218 
1219 static inline bool pmd_user_accessible_page(pmd_t pmd)
1220 {
1221 	return pmd_valid(pmd) && !pmd_table(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
1222 }
1223 
1224 static inline bool pud_user_accessible_page(pud_t pud)
1225 {
1226 	return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
1227 }
1228 #endif
1229 
1230 /*
1231  * Atomic pte/pmd modifications.
1232  */
1233 static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma,
1234 					      unsigned long address,
1235 					      pte_t *ptep)
1236 {
1237 	pte_t old_pte, pte;
1238 
1239 	pte = __ptep_get(ptep);
1240 	do {
1241 		old_pte = pte;
1242 		pte = pte_mkold(pte);
1243 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1244 					       pte_val(old_pte), pte_val(pte));
1245 	} while (pte_val(pte) != pte_val(old_pte));
1246 
1247 	return pte_young(pte);
1248 }
1249 
1250 static inline int __ptep_clear_flush_young(struct vm_area_struct *vma,
1251 					 unsigned long address, pte_t *ptep)
1252 {
1253 	int young = __ptep_test_and_clear_young(vma, address, ptep);
1254 
1255 	if (young) {
1256 		/*
1257 		 * We can elide the trailing DSB here since the worst that can
1258 		 * happen is that a CPU continues to use the young entry in its
1259 		 * TLB and we mistakenly reclaim the associated page. The
1260 		 * window for such an event is bounded by the next
1261 		 * context-switch, which provides a DSB to complete the TLB
1262 		 * invalidation.
1263 		 */
1264 		flush_tlb_page_nosync(vma, address);
1265 	}
1266 
1267 	return young;
1268 }
1269 
1270 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
1271 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1272 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1273 					    unsigned long address,
1274 					    pmd_t *pmdp)
1275 {
1276 	/* Operation applies to PMD table entry only if FEAT_HAFT is enabled */
1277 	VM_WARN_ON(pmd_table(READ_ONCE(*pmdp)) && !system_supports_haft());
1278 	return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1279 }
1280 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
1281 
1282 static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
1283 				       unsigned long address, pte_t *ptep)
1284 {
1285 	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
1286 
1287 	page_table_check_pte_clear(mm, pte);
1288 
1289 	return pte;
1290 }
1291 
1292 static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1293 				pte_t *ptep, unsigned int nr, int full)
1294 {
1295 	for (;;) {
1296 		__ptep_get_and_clear(mm, addr, ptep);
1297 		if (--nr == 0)
1298 			break;
1299 		ptep++;
1300 		addr += PAGE_SIZE;
1301 	}
1302 }
1303 
1304 static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm,
1305 				unsigned long addr, pte_t *ptep,
1306 				unsigned int nr, int full)
1307 {
1308 	pte_t pte, tmp_pte;
1309 
1310 	pte = __ptep_get_and_clear(mm, addr, ptep);
1311 	while (--nr) {
1312 		ptep++;
1313 		addr += PAGE_SIZE;
1314 		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
1315 		if (pte_dirty(tmp_pte))
1316 			pte = pte_mkdirty(pte);
1317 		if (pte_young(tmp_pte))
1318 			pte = pte_mkyoung(pte);
1319 	}
1320 	return pte;
1321 }
1322 
1323 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1324 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1325 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1326 					    unsigned long address, pmd_t *pmdp)
1327 {
1328 	pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0));
1329 
1330 	page_table_check_pmd_clear(mm, pmd);
1331 
1332 	return pmd;
1333 }
1334 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1335 
1336 static inline void ___ptep_set_wrprotect(struct mm_struct *mm,
1337 					unsigned long address, pte_t *ptep,
1338 					pte_t pte)
1339 {
1340 	pte_t old_pte;
1341 
1342 	do {
1343 		old_pte = pte;
1344 		pte = pte_wrprotect(pte);
1345 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1346 					       pte_val(old_pte), pte_val(pte));
1347 	} while (pte_val(pte) != pte_val(old_pte));
1348 }
1349 
1350 /*
1351  * __ptep_set_wrprotect - mark read-only while transferring potential hardware
1352  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
1353  */
1354 static inline void __ptep_set_wrprotect(struct mm_struct *mm,
1355 					unsigned long address, pte_t *ptep)
1356 {
1357 	___ptep_set_wrprotect(mm, address, ptep, __ptep_get(ptep));
1358 }
1359 
1360 static inline void __wrprotect_ptes(struct mm_struct *mm, unsigned long address,
1361 				pte_t *ptep, unsigned int nr)
1362 {
1363 	unsigned int i;
1364 
1365 	for (i = 0; i < nr; i++, address += PAGE_SIZE, ptep++)
1366 		__ptep_set_wrprotect(mm, address, ptep);
1367 }
1368 
1369 static inline void __clear_young_dirty_pte(struct vm_area_struct *vma,
1370 					   unsigned long addr, pte_t *ptep,
1371 					   pte_t pte, cydp_t flags)
1372 {
1373 	pte_t old_pte;
1374 
1375 	do {
1376 		old_pte = pte;
1377 
1378 		if (flags & CYDP_CLEAR_YOUNG)
1379 			pte = pte_mkold(pte);
1380 		if (flags & CYDP_CLEAR_DIRTY)
1381 			pte = pte_mkclean(pte);
1382 
1383 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1384 					       pte_val(old_pte), pte_val(pte));
1385 	} while (pte_val(pte) != pte_val(old_pte));
1386 }
1387 
1388 static inline void __clear_young_dirty_ptes(struct vm_area_struct *vma,
1389 					    unsigned long addr, pte_t *ptep,
1390 					    unsigned int nr, cydp_t flags)
1391 {
1392 	pte_t pte;
1393 
1394 	for (;;) {
1395 		pte = __ptep_get(ptep);
1396 
1397 		if (flags == (CYDP_CLEAR_YOUNG | CYDP_CLEAR_DIRTY))
1398 			__set_pte(ptep, pte_mkclean(pte_mkold(pte)));
1399 		else
1400 			__clear_young_dirty_pte(vma, addr, ptep, pte, flags);
1401 
1402 		if (--nr == 0)
1403 			break;
1404 		ptep++;
1405 		addr += PAGE_SIZE;
1406 	}
1407 }
1408 
1409 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1410 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1411 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1412 				      unsigned long address, pmd_t *pmdp)
1413 {
1414 	__ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1415 }
1416 
1417 #define pmdp_establish pmdp_establish
1418 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1419 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
1420 {
1421 	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
1422 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
1423 }
1424 #endif
1425 
1426 /*
1427  * Encode and decode a swap entry:
1428  *	bits 0-1:	present (must be zero)
1429  *	bits 2:		remember PG_anon_exclusive
1430  *	bit  3:		remember uffd-wp state
1431  *	bits 6-10:	swap type
1432  *	bit  11:	PTE_PRESENT_INVALID (must be zero)
1433  *	bits 12-61:	swap offset
1434  */
1435 #define __SWP_TYPE_SHIFT	6
1436 #define __SWP_TYPE_BITS		5
1437 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
1438 #define __SWP_OFFSET_SHIFT	12
1439 #define __SWP_OFFSET_BITS	50
1440 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
1441 
1442 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1443 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
1444 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
1445 
1446 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1447 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
1448 
1449 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1450 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
1451 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
1452 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
1453 
1454 /*
1455  * Ensure that there are not more swap files than can be encoded in the kernel
1456  * PTEs.
1457  */
1458 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1459 
1460 #ifdef CONFIG_ARM64_MTE
1461 
1462 #define __HAVE_ARCH_PREPARE_TO_SWAP
1463 extern int arch_prepare_to_swap(struct folio *folio);
1464 
1465 #define __HAVE_ARCH_SWAP_INVALIDATE
1466 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
1467 {
1468 	if (system_supports_mte())
1469 		mte_invalidate_tags(type, offset);
1470 }
1471 
1472 static inline void arch_swap_invalidate_area(int type)
1473 {
1474 	if (system_supports_mte())
1475 		mte_invalidate_tags_area(type);
1476 }
1477 
1478 #define __HAVE_ARCH_SWAP_RESTORE
1479 extern void arch_swap_restore(swp_entry_t entry, struct folio *folio);
1480 
1481 #endif /* CONFIG_ARM64_MTE */
1482 
1483 /*
1484  * On AArch64, the cache coherency is handled via the __set_ptes() function.
1485  */
1486 static inline void update_mmu_cache_range(struct vm_fault *vmf,
1487 		struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
1488 		unsigned int nr)
1489 {
1490 	/*
1491 	 * We don't do anything here, so there's a very small chance of
1492 	 * us retaking a user fault which we just fixed up. The alternative
1493 	 * is doing a dsb(ishst), but that penalises the fastpath.
1494 	 */
1495 }
1496 
1497 #define update_mmu_cache(vma, addr, ptep) \
1498 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
1499 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
1500 
1501 #ifdef CONFIG_ARM64_PA_BITS_52
1502 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
1503 #else
1504 #define phys_to_ttbr(addr)	(addr)
1505 #endif
1506 
1507 /*
1508  * On arm64 without hardware Access Flag, copying from user will fail because
1509  * the pte is old and cannot be marked young. So we always end up with zeroed
1510  * page after fork() + CoW for pfn mappings. We don't always have a
1511  * hardware-managed access flag on arm64.
1512  */
1513 #define arch_has_hw_pte_young		cpu_has_hw_af
1514 
1515 #ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
1516 #define arch_has_hw_nonleaf_pmd_young	system_supports_haft
1517 #endif
1518 
1519 /*
1520  * Experimentally, it's cheap to set the access flag in hardware and we
1521  * benefit from prefaulting mappings as 'old' to start with.
1522  */
1523 #define arch_wants_old_prefaulted_pte	cpu_has_hw_af
1524 
1525 static inline bool pud_sect_supported(void)
1526 {
1527 	return PAGE_SIZE == SZ_4K;
1528 }
1529 
1530 
1531 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1532 #define ptep_modify_prot_start ptep_modify_prot_start
1533 extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
1534 				    unsigned long addr, pte_t *ptep);
1535 
1536 #define ptep_modify_prot_commit ptep_modify_prot_commit
1537 extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
1538 				    unsigned long addr, pte_t *ptep,
1539 				    pte_t old_pte, pte_t new_pte);
1540 
1541 #ifdef CONFIG_ARM64_CONTPTE
1542 
1543 /*
1544  * The contpte APIs are used to transparently manage the contiguous bit in ptes
1545  * where it is possible and makes sense to do so. The PTE_CONT bit is considered
1546  * a private implementation detail of the public ptep API (see below).
1547  */
1548 extern void __contpte_try_fold(struct mm_struct *mm, unsigned long addr,
1549 				pte_t *ptep, pte_t pte);
1550 extern void __contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
1551 				pte_t *ptep, pte_t pte);
1552 extern pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte);
1553 extern pte_t contpte_ptep_get_lockless(pte_t *orig_ptep);
1554 extern void contpte_set_ptes(struct mm_struct *mm, unsigned long addr,
1555 				pte_t *ptep, pte_t pte, unsigned int nr);
1556 extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1557 				pte_t *ptep, unsigned int nr, int full);
1558 extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
1559 				unsigned long addr, pte_t *ptep,
1560 				unsigned int nr, int full);
1561 extern int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma,
1562 				unsigned long addr, pte_t *ptep);
1563 extern int contpte_ptep_clear_flush_young(struct vm_area_struct *vma,
1564 				unsigned long addr, pte_t *ptep);
1565 extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
1566 				pte_t *ptep, unsigned int nr);
1567 extern int contpte_ptep_set_access_flags(struct vm_area_struct *vma,
1568 				unsigned long addr, pte_t *ptep,
1569 				pte_t entry, int dirty);
1570 extern void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,
1571 				unsigned long addr, pte_t *ptep,
1572 				unsigned int nr, cydp_t flags);
1573 
1574 static __always_inline void contpte_try_fold(struct mm_struct *mm,
1575 				unsigned long addr, pte_t *ptep, pte_t pte)
1576 {
1577 	/*
1578 	 * Only bother trying if both the virtual and physical addresses are
1579 	 * aligned and correspond to the last entry in a contig range. The core
1580 	 * code mostly modifies ranges from low to high, so this is the likely
1581 	 * the last modification in the contig range, so a good time to fold.
1582 	 * We can't fold special mappings, because there is no associated folio.
1583 	 */
1584 
1585 	const unsigned long contmask = CONT_PTES - 1;
1586 	bool valign = ((addr >> PAGE_SHIFT) & contmask) == contmask;
1587 
1588 	if (unlikely(valign)) {
1589 		bool palign = (pte_pfn(pte) & contmask) == contmask;
1590 
1591 		if (unlikely(palign &&
1592 		    pte_valid(pte) && !pte_cont(pte) && !pte_special(pte)))
1593 			__contpte_try_fold(mm, addr, ptep, pte);
1594 	}
1595 }
1596 
1597 static __always_inline void contpte_try_unfold(struct mm_struct *mm,
1598 				unsigned long addr, pte_t *ptep, pte_t pte)
1599 {
1600 	if (unlikely(pte_valid_cont(pte)))
1601 		__contpte_try_unfold(mm, addr, ptep, pte);
1602 }
1603 
1604 #define pte_batch_hint pte_batch_hint
1605 static inline unsigned int pte_batch_hint(pte_t *ptep, pte_t pte)
1606 {
1607 	if (!pte_valid_cont(pte))
1608 		return 1;
1609 
1610 	return CONT_PTES - (((unsigned long)ptep >> 3) & (CONT_PTES - 1));
1611 }
1612 
1613 /*
1614  * The below functions constitute the public API that arm64 presents to the
1615  * core-mm to manipulate PTE entries within their page tables (or at least this
1616  * is the subset of the API that arm64 needs to implement). These public
1617  * versions will automatically and transparently apply the contiguous bit where
1618  * it makes sense to do so. Therefore any users that are contig-aware (e.g.
1619  * hugetlb, kernel mapper) should NOT use these APIs, but instead use the
1620  * private versions, which are prefixed with double underscore. All of these
1621  * APIs except for ptep_get_lockless() are expected to be called with the PTL
1622  * held. Although the contiguous bit is considered private to the
1623  * implementation, it is deliberately allowed to leak through the getters (e.g.
1624  * ptep_get()), back to core code. This is required so that pte_leaf_size() can
1625  * provide an accurate size for perf_get_pgtable_size(). But this leakage means
1626  * its possible a pte will be passed to a setter with the contiguous bit set, so
1627  * we explicitly clear the contiguous bit in those cases to prevent accidentally
1628  * setting it in the pgtable.
1629  */
1630 
1631 #define ptep_get ptep_get
1632 static inline pte_t ptep_get(pte_t *ptep)
1633 {
1634 	pte_t pte = __ptep_get(ptep);
1635 
1636 	if (likely(!pte_valid_cont(pte)))
1637 		return pte;
1638 
1639 	return contpte_ptep_get(ptep, pte);
1640 }
1641 
1642 #define ptep_get_lockless ptep_get_lockless
1643 static inline pte_t ptep_get_lockless(pte_t *ptep)
1644 {
1645 	pte_t pte = __ptep_get(ptep);
1646 
1647 	if (likely(!pte_valid_cont(pte)))
1648 		return pte;
1649 
1650 	return contpte_ptep_get_lockless(ptep);
1651 }
1652 
1653 static inline void set_pte(pte_t *ptep, pte_t pte)
1654 {
1655 	/*
1656 	 * We don't have the mm or vaddr so cannot unfold contig entries (since
1657 	 * it requires tlb maintenance). set_pte() is not used in core code, so
1658 	 * this should never even be called. Regardless do our best to service
1659 	 * any call and emit a warning if there is any attempt to set a pte on
1660 	 * top of an existing contig range.
1661 	 */
1662 	pte_t orig_pte = __ptep_get(ptep);
1663 
1664 	WARN_ON_ONCE(pte_valid_cont(orig_pte));
1665 	__set_pte(ptep, pte_mknoncont(pte));
1666 }
1667 
1668 #define set_ptes set_ptes
1669 static __always_inline void set_ptes(struct mm_struct *mm, unsigned long addr,
1670 				pte_t *ptep, pte_t pte, unsigned int nr)
1671 {
1672 	pte = pte_mknoncont(pte);
1673 
1674 	if (likely(nr == 1)) {
1675 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1676 		__set_ptes(mm, addr, ptep, pte, 1);
1677 		contpte_try_fold(mm, addr, ptep, pte);
1678 	} else {
1679 		contpte_set_ptes(mm, addr, ptep, pte, nr);
1680 	}
1681 }
1682 
1683 static inline void pte_clear(struct mm_struct *mm,
1684 				unsigned long addr, pte_t *ptep)
1685 {
1686 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1687 	__pte_clear(mm, addr, ptep);
1688 }
1689 
1690 #define clear_full_ptes clear_full_ptes
1691 static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1692 				pte_t *ptep, unsigned int nr, int full)
1693 {
1694 	if (likely(nr == 1)) {
1695 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1696 		__clear_full_ptes(mm, addr, ptep, nr, full);
1697 	} else {
1698 		contpte_clear_full_ptes(mm, addr, ptep, nr, full);
1699 	}
1700 }
1701 
1702 #define get_and_clear_full_ptes get_and_clear_full_ptes
1703 static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm,
1704 				unsigned long addr, pte_t *ptep,
1705 				unsigned int nr, int full)
1706 {
1707 	pte_t pte;
1708 
1709 	if (likely(nr == 1)) {
1710 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1711 		pte = __get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1712 	} else {
1713 		pte = contpte_get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1714 	}
1715 
1716 	return pte;
1717 }
1718 
1719 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1720 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1721 				unsigned long addr, pte_t *ptep)
1722 {
1723 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1724 	return __ptep_get_and_clear(mm, addr, ptep);
1725 }
1726 
1727 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1728 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
1729 				unsigned long addr, pte_t *ptep)
1730 {
1731 	pte_t orig_pte = __ptep_get(ptep);
1732 
1733 	if (likely(!pte_valid_cont(orig_pte)))
1734 		return __ptep_test_and_clear_young(vma, addr, ptep);
1735 
1736 	return contpte_ptep_test_and_clear_young(vma, addr, ptep);
1737 }
1738 
1739 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1740 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
1741 				unsigned long addr, pte_t *ptep)
1742 {
1743 	pte_t orig_pte = __ptep_get(ptep);
1744 
1745 	if (likely(!pte_valid_cont(orig_pte)))
1746 		return __ptep_clear_flush_young(vma, addr, ptep);
1747 
1748 	return contpte_ptep_clear_flush_young(vma, addr, ptep);
1749 }
1750 
1751 #define wrprotect_ptes wrprotect_ptes
1752 static __always_inline void wrprotect_ptes(struct mm_struct *mm,
1753 				unsigned long addr, pte_t *ptep, unsigned int nr)
1754 {
1755 	if (likely(nr == 1)) {
1756 		/*
1757 		 * Optimization: wrprotect_ptes() can only be called for present
1758 		 * ptes so we only need to check contig bit as condition for
1759 		 * unfold, and we can remove the contig bit from the pte we read
1760 		 * to avoid re-reading. This speeds up fork() which is sensitive
1761 		 * for order-0 folios. Equivalent to contpte_try_unfold().
1762 		 */
1763 		pte_t orig_pte = __ptep_get(ptep);
1764 
1765 		if (unlikely(pte_cont(orig_pte))) {
1766 			__contpte_try_unfold(mm, addr, ptep, orig_pte);
1767 			orig_pte = pte_mknoncont(orig_pte);
1768 		}
1769 		___ptep_set_wrprotect(mm, addr, ptep, orig_pte);
1770 	} else {
1771 		contpte_wrprotect_ptes(mm, addr, ptep, nr);
1772 	}
1773 }
1774 
1775 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1776 static inline void ptep_set_wrprotect(struct mm_struct *mm,
1777 				unsigned long addr, pte_t *ptep)
1778 {
1779 	wrprotect_ptes(mm, addr, ptep, 1);
1780 }
1781 
1782 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1783 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1784 				unsigned long addr, pte_t *ptep,
1785 				pte_t entry, int dirty)
1786 {
1787 	pte_t orig_pte = __ptep_get(ptep);
1788 
1789 	entry = pte_mknoncont(entry);
1790 
1791 	if (likely(!pte_valid_cont(orig_pte)))
1792 		return __ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1793 
1794 	return contpte_ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1795 }
1796 
1797 #define clear_young_dirty_ptes clear_young_dirty_ptes
1798 static inline void clear_young_dirty_ptes(struct vm_area_struct *vma,
1799 					  unsigned long addr, pte_t *ptep,
1800 					  unsigned int nr, cydp_t flags)
1801 {
1802 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
1803 		__clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1804 	else
1805 		contpte_clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1806 }
1807 
1808 #else /* CONFIG_ARM64_CONTPTE */
1809 
1810 #define ptep_get				__ptep_get
1811 #define set_pte					__set_pte
1812 #define set_ptes				__set_ptes
1813 #define pte_clear				__pte_clear
1814 #define clear_full_ptes				__clear_full_ptes
1815 #define get_and_clear_full_ptes			__get_and_clear_full_ptes
1816 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1817 #define ptep_get_and_clear			__ptep_get_and_clear
1818 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1819 #define ptep_test_and_clear_young		__ptep_test_and_clear_young
1820 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1821 #define ptep_clear_flush_young			__ptep_clear_flush_young
1822 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1823 #define ptep_set_wrprotect			__ptep_set_wrprotect
1824 #define wrprotect_ptes				__wrprotect_ptes
1825 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1826 #define ptep_set_access_flags			__ptep_set_access_flags
1827 #define clear_young_dirty_ptes			__clear_young_dirty_ptes
1828 
1829 #endif /* CONFIG_ARM64_CONTPTE */
1830 
1831 #endif /* !__ASSEMBLY__ */
1832 
1833 #endif /* __ASM_PGTABLE_H */
1834