xref: /linux/arch/arm64/include/asm/pgtable.h (revision a9fc2304972b1db28b88af8203dffef23e1e92ba)
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_TYPE_MASK) | 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_TYPE_MASK) | 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 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
555 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
556 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
557 #define pmd_user(pmd)		pte_user(pmd_pte(pmd))
558 #define pmd_user_exec(pmd)	pte_user_exec(pmd_pte(pmd))
559 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
560 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
561 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
562 #define pmd_mkwrite_novma(pmd)	pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)))
563 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
564 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
565 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
566 #define pmd_mkinvalid(pmd)	pte_pmd(pte_mkinvalid(pmd_pte(pmd)))
567 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
568 #define pmd_uffd_wp(pmd)	pte_uffd_wp(pmd_pte(pmd))
569 #define pmd_mkuffd_wp(pmd)	pte_pmd(pte_mkuffd_wp(pmd_pte(pmd)))
570 #define pmd_clear_uffd_wp(pmd)	pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd)))
571 #define pmd_swp_uffd_wp(pmd)	pte_swp_uffd_wp(pmd_pte(pmd))
572 #define pmd_swp_mkuffd_wp(pmd)	pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd)))
573 #define pmd_swp_clear_uffd_wp(pmd) \
574 				pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd)))
575 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
576 
577 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
578 
579 static inline pmd_t pmd_mkhuge(pmd_t pmd)
580 {
581 	/*
582 	 * It's possible that the pmd is present-invalid on entry
583 	 * and in that case it needs to remain present-invalid on
584 	 * exit. So ensure the VALID bit does not get modified.
585 	 */
586 	pmdval_t mask = PMD_TYPE_MASK & ~PTE_VALID;
587 	pmdval_t val = PMD_TYPE_SECT & ~PTE_VALID;
588 
589 	return __pmd((pmd_val(pmd) & ~mask) | val);
590 }
591 
592 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
593 #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
594 #endif
595 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
596 {
597 	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
598 }
599 
600 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
601 #define pmd_special(pte)	(!!((pmd_val(pte) & PTE_SPECIAL)))
602 static inline pmd_t pmd_mkspecial(pmd_t pmd)
603 {
604 	return set_pmd_bit(pmd, __pgprot(PTE_SPECIAL));
605 }
606 #endif
607 
608 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
609 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
610 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
611 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
612 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
613 
614 #define pud_young(pud)		pte_young(pud_pte(pud))
615 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
616 #define pud_write(pud)		pte_write(pud_pte(pud))
617 
618 static inline pud_t pud_mkhuge(pud_t pud)
619 {
620 	/*
621 	 * It's possible that the pud is present-invalid on entry
622 	 * and in that case it needs to remain present-invalid on
623 	 * exit. So ensure the VALID bit does not get modified.
624 	 */
625 	pudval_t mask = PUD_TYPE_MASK & ~PTE_VALID;
626 	pudval_t val = PUD_TYPE_SECT & ~PTE_VALID;
627 
628 	return __pud((pud_val(pud) & ~mask) | val);
629 }
630 
631 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
632 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
633 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
634 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
635 
636 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
637 #define pud_special(pte)	pte_special(pud_pte(pud))
638 #define pud_mkspecial(pte)	pte_pud(pte_mkspecial(pud_pte(pud)))
639 #endif
640 
641 #define pmd_pgprot pmd_pgprot
642 static inline pgprot_t pmd_pgprot(pmd_t pmd)
643 {
644 	unsigned long pfn = pmd_pfn(pmd);
645 
646 	return __pgprot(pmd_val(pfn_pmd(pfn, __pgprot(0))) ^ pmd_val(pmd));
647 }
648 
649 #define pud_pgprot pud_pgprot
650 static inline pgprot_t pud_pgprot(pud_t pud)
651 {
652 	unsigned long pfn = pud_pfn(pud);
653 
654 	return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud));
655 }
656 
657 static inline void __set_pte_at(struct mm_struct *mm,
658 				unsigned long __always_unused addr,
659 				pte_t *ptep, pte_t pte, unsigned int nr)
660 {
661 	__sync_cache_and_tags(pte, nr);
662 	__check_safe_pte_update(mm, ptep, pte);
663 	__set_pte(ptep, pte);
664 }
665 
666 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
667 			      pmd_t *pmdp, pmd_t pmd)
668 {
669 	page_table_check_pmd_set(mm, pmdp, pmd);
670 	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd),
671 						PMD_SIZE >> PAGE_SHIFT);
672 }
673 
674 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
675 			      pud_t *pudp, pud_t pud)
676 {
677 	page_table_check_pud_set(mm, pudp, pud);
678 	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud),
679 						PUD_SIZE >> PAGE_SHIFT);
680 }
681 
682 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
683 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
684 
685 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
686 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
687 
688 #define __pgprot_modify(prot,mask,bits) \
689 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
690 
691 #define pgprot_nx(prot) \
692 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
693 
694 #define pgprot_decrypted(prot) \
695 	__pgprot_modify(prot, PROT_NS_SHARED, PROT_NS_SHARED)
696 #define pgprot_encrypted(prot) \
697 	__pgprot_modify(prot, PROT_NS_SHARED, 0)
698 
699 /*
700  * Mark the prot value as uncacheable and unbufferable.
701  */
702 #define pgprot_noncached(prot) \
703 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
704 #define pgprot_writecombine(prot) \
705 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
706 #define pgprot_device(prot) \
707 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
708 #define pgprot_tagged(prot) \
709 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
710 #define pgprot_mhp	pgprot_tagged
711 /*
712  * DMA allocations for non-coherent devices use what the Arm architecture calls
713  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
714  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
715  * is intended for MMIO and thus forbids speculation, preserves access size,
716  * requires strict alignment and can also force write responses to come from the
717  * endpoint.
718  */
719 #define pgprot_dmacoherent(prot) \
720 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
721 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
722 
723 #define __HAVE_PHYS_MEM_ACCESS_PROT
724 struct file;
725 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
726 				     unsigned long size, pgprot_t vma_prot);
727 
728 #define pmd_none(pmd)		(!pmd_val(pmd))
729 
730 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
731 				 PMD_TYPE_TABLE)
732 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
733 				 PMD_TYPE_SECT)
734 #define pmd_leaf(pmd)		(pmd_present(pmd) && !pmd_table(pmd))
735 #define pmd_bad(pmd)		(!pmd_table(pmd))
736 
737 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
738 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
739 
740 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
741 static inline int pmd_trans_huge(pmd_t pmd)
742 {
743 	/*
744 	 * If pmd is present-invalid, pmd_table() won't detect it
745 	 * as a table, so force the valid bit for the comparison.
746 	 */
747 	return pmd_val(pmd) && pmd_present(pmd) &&
748 	       !pmd_table(__pmd(pmd_val(pmd) | PTE_VALID));
749 }
750 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
751 
752 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
753 static inline bool pud_sect(pud_t pud) { return false; }
754 static inline bool pud_table(pud_t pud) { return true; }
755 #else
756 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
757 				 PUD_TYPE_SECT)
758 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
759 				 PUD_TYPE_TABLE)
760 #endif
761 
762 extern pgd_t init_pg_dir[];
763 extern pgd_t init_pg_end[];
764 extern pgd_t swapper_pg_dir[];
765 extern pgd_t idmap_pg_dir[];
766 extern pgd_t tramp_pg_dir[];
767 extern pgd_t reserved_pg_dir[];
768 
769 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
770 
771 static inline bool in_swapper_pgdir(void *addr)
772 {
773 	return ((unsigned long)addr & PAGE_MASK) ==
774 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
775 }
776 
777 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
778 {
779 #ifdef __PAGETABLE_PMD_FOLDED
780 	if (in_swapper_pgdir(pmdp)) {
781 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
782 		return;
783 	}
784 #endif /* __PAGETABLE_PMD_FOLDED */
785 
786 	WRITE_ONCE(*pmdp, pmd);
787 
788 	if (pmd_valid(pmd)) {
789 		dsb(ishst);
790 		isb();
791 	}
792 }
793 
794 static inline void pmd_clear(pmd_t *pmdp)
795 {
796 	set_pmd(pmdp, __pmd(0));
797 }
798 
799 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
800 {
801 	return __pmd_to_phys(pmd);
802 }
803 
804 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
805 {
806 	return (unsigned long)__va(pmd_page_paddr(pmd));
807 }
808 
809 /* Find an entry in the third-level page table. */
810 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
811 
812 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
813 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
814 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
815 
816 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
817 
818 /* use ONLY for statically allocated translation tables */
819 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
820 
821 /*
822  * Conversion functions: convert a page and protection to a page entry,
823  * and a page entry and page directory to the page they refer to.
824  */
825 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
826 
827 #if CONFIG_PGTABLE_LEVELS > 2
828 
829 #define pmd_ERROR(e)	\
830 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
831 
832 #define pud_none(pud)		(!pud_val(pud))
833 #define pud_bad(pud)		((pud_val(pud) & PUD_TYPE_MASK) != \
834 				 PUD_TYPE_TABLE)
835 #define pud_present(pud)	pte_present(pud_pte(pud))
836 #ifndef __PAGETABLE_PMD_FOLDED
837 #define pud_leaf(pud)		(pud_present(pud) && !pud_table(pud))
838 #else
839 #define pud_leaf(pud)		false
840 #endif
841 #define pud_valid(pud)		pte_valid(pud_pte(pud))
842 #define pud_user(pud)		pte_user(pud_pte(pud))
843 #define pud_user_exec(pud)	pte_user_exec(pud_pte(pud))
844 
845 static inline bool pgtable_l4_enabled(void);
846 
847 static inline void set_pud(pud_t *pudp, pud_t pud)
848 {
849 	if (!pgtable_l4_enabled() && in_swapper_pgdir(pudp)) {
850 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
851 		return;
852 	}
853 
854 	WRITE_ONCE(*pudp, pud);
855 
856 	if (pud_valid(pud)) {
857 		dsb(ishst);
858 		isb();
859 	}
860 }
861 
862 static inline void pud_clear(pud_t *pudp)
863 {
864 	set_pud(pudp, __pud(0));
865 }
866 
867 static inline phys_addr_t pud_page_paddr(pud_t pud)
868 {
869 	return __pud_to_phys(pud);
870 }
871 
872 static inline pmd_t *pud_pgtable(pud_t pud)
873 {
874 	return (pmd_t *)__va(pud_page_paddr(pud));
875 }
876 
877 /* Find an entry in the second-level page table. */
878 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
879 
880 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
881 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
882 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
883 
884 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
885 
886 /* use ONLY for statically allocated translation tables */
887 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
888 
889 #else
890 
891 #define pud_valid(pud)		false
892 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
893 #define pud_user_exec(pud)	pud_user(pud) /* Always 0 with folding */
894 
895 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
896 #define pmd_set_fixmap(addr)		NULL
897 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
898 #define pmd_clear_fixmap()
899 
900 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
901 
902 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
903 
904 #if CONFIG_PGTABLE_LEVELS > 3
905 
906 static __always_inline bool pgtable_l4_enabled(void)
907 {
908 	if (CONFIG_PGTABLE_LEVELS > 4 || !IS_ENABLED(CONFIG_ARM64_LPA2))
909 		return true;
910 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
911 		return vabits_actual == VA_BITS;
912 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
913 }
914 
915 static inline bool mm_pud_folded(const struct mm_struct *mm)
916 {
917 	return !pgtable_l4_enabled();
918 }
919 #define mm_pud_folded  mm_pud_folded
920 
921 #define pud_ERROR(e)	\
922 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
923 
924 #define p4d_none(p4d)		(pgtable_l4_enabled() && !p4d_val(p4d))
925 #define p4d_bad(p4d)		(pgtable_l4_enabled() && \
926 				((p4d_val(p4d) & P4D_TYPE_MASK) != \
927 				 P4D_TYPE_TABLE))
928 #define p4d_present(p4d)	(!p4d_none(p4d))
929 
930 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
931 {
932 	if (in_swapper_pgdir(p4dp)) {
933 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
934 		return;
935 	}
936 
937 	WRITE_ONCE(*p4dp, p4d);
938 	dsb(ishst);
939 	isb();
940 }
941 
942 static inline void p4d_clear(p4d_t *p4dp)
943 {
944 	if (pgtable_l4_enabled())
945 		set_p4d(p4dp, __p4d(0));
946 }
947 
948 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
949 {
950 	return __p4d_to_phys(p4d);
951 }
952 
953 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
954 
955 static inline pud_t *p4d_to_folded_pud(p4d_t *p4dp, unsigned long addr)
956 {
957 	/* Ensure that 'p4dp' indexes a page table according to 'addr' */
958 	VM_BUG_ON(((addr >> P4D_SHIFT) ^ ((u64)p4dp >> 3)) % PTRS_PER_P4D);
959 
960 	return (pud_t *)PTR_ALIGN_DOWN(p4dp, PAGE_SIZE) + pud_index(addr);
961 }
962 
963 static inline pud_t *p4d_pgtable(p4d_t p4d)
964 {
965 	return (pud_t *)__va(p4d_page_paddr(p4d));
966 }
967 
968 static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr)
969 {
970 	BUG_ON(!pgtable_l4_enabled());
971 
972 	return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t);
973 }
974 
975 static inline
976 pud_t *pud_offset_lockless(p4d_t *p4dp, p4d_t p4d, unsigned long addr)
977 {
978 	if (!pgtable_l4_enabled())
979 		return p4d_to_folded_pud(p4dp, addr);
980 	return (pud_t *)__va(p4d_page_paddr(p4d)) + pud_index(addr);
981 }
982 #define pud_offset_lockless pud_offset_lockless
983 
984 static inline pud_t *pud_offset(p4d_t *p4dp, unsigned long addr)
985 {
986 	return pud_offset_lockless(p4dp, READ_ONCE(*p4dp), addr);
987 }
988 #define pud_offset	pud_offset
989 
990 static inline pud_t *pud_set_fixmap(unsigned long addr)
991 {
992 	if (!pgtable_l4_enabled())
993 		return NULL;
994 	return (pud_t *)set_fixmap_offset(FIX_PUD, addr);
995 }
996 
997 static inline pud_t *pud_set_fixmap_offset(p4d_t *p4dp, unsigned long addr)
998 {
999 	if (!pgtable_l4_enabled())
1000 		return p4d_to_folded_pud(p4dp, addr);
1001 	return pud_set_fixmap(pud_offset_phys(p4dp, addr));
1002 }
1003 
1004 static inline void pud_clear_fixmap(void)
1005 {
1006 	if (pgtable_l4_enabled())
1007 		clear_fixmap(FIX_PUD);
1008 }
1009 
1010 /* use ONLY for statically allocated translation tables */
1011 static inline pud_t *pud_offset_kimg(p4d_t *p4dp, u64 addr)
1012 {
1013 	if (!pgtable_l4_enabled())
1014 		return p4d_to_folded_pud(p4dp, addr);
1015 	return (pud_t *)__phys_to_kimg(pud_offset_phys(p4dp, addr));
1016 }
1017 
1018 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
1019 
1020 #else
1021 
1022 static inline bool pgtable_l4_enabled(void) { return false; }
1023 
1024 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
1025 
1026 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
1027 #define pud_set_fixmap(addr)		NULL
1028 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
1029 #define pud_clear_fixmap()
1030 
1031 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
1032 
1033 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
1034 
1035 #if CONFIG_PGTABLE_LEVELS > 4
1036 
1037 static __always_inline bool pgtable_l5_enabled(void)
1038 {
1039 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
1040 		return vabits_actual == VA_BITS;
1041 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
1042 }
1043 
1044 static inline bool mm_p4d_folded(const struct mm_struct *mm)
1045 {
1046 	return !pgtable_l5_enabled();
1047 }
1048 #define mm_p4d_folded  mm_p4d_folded
1049 
1050 #define p4d_ERROR(e)	\
1051 	pr_err("%s:%d: bad p4d %016llx.\n", __FILE__, __LINE__, p4d_val(e))
1052 
1053 #define pgd_none(pgd)		(pgtable_l5_enabled() && !pgd_val(pgd))
1054 #define pgd_bad(pgd)		(pgtable_l5_enabled() && \
1055 				((pgd_val(pgd) & PGD_TYPE_MASK) != \
1056 				 PGD_TYPE_TABLE))
1057 #define pgd_present(pgd)	(!pgd_none(pgd))
1058 
1059 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
1060 {
1061 	if (in_swapper_pgdir(pgdp)) {
1062 		set_swapper_pgd(pgdp, __pgd(pgd_val(pgd)));
1063 		return;
1064 	}
1065 
1066 	WRITE_ONCE(*pgdp, pgd);
1067 	dsb(ishst);
1068 	isb();
1069 }
1070 
1071 static inline void pgd_clear(pgd_t *pgdp)
1072 {
1073 	if (pgtable_l5_enabled())
1074 		set_pgd(pgdp, __pgd(0));
1075 }
1076 
1077 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
1078 {
1079 	return __pgd_to_phys(pgd);
1080 }
1081 
1082 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1083 
1084 static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr)
1085 {
1086 	/* Ensure that 'pgdp' indexes a page table according to 'addr' */
1087 	VM_BUG_ON(((addr >> PGDIR_SHIFT) ^ ((u64)pgdp >> 3)) % PTRS_PER_PGD);
1088 
1089 	return (p4d_t *)PTR_ALIGN_DOWN(pgdp, PAGE_SIZE) + p4d_index(addr);
1090 }
1091 
1092 static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr)
1093 {
1094 	BUG_ON(!pgtable_l5_enabled());
1095 
1096 	return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t);
1097 }
1098 
1099 static inline
1100 p4d_t *p4d_offset_lockless(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1101 {
1102 	if (!pgtable_l5_enabled())
1103 		return pgd_to_folded_p4d(pgdp, addr);
1104 	return (p4d_t *)__va(pgd_page_paddr(pgd)) + p4d_index(addr);
1105 }
1106 #define p4d_offset_lockless p4d_offset_lockless
1107 
1108 static inline p4d_t *p4d_offset(pgd_t *pgdp, unsigned long addr)
1109 {
1110 	return p4d_offset_lockless(pgdp, READ_ONCE(*pgdp), addr);
1111 }
1112 
1113 static inline p4d_t *p4d_set_fixmap(unsigned long addr)
1114 {
1115 	if (!pgtable_l5_enabled())
1116 		return NULL;
1117 	return (p4d_t *)set_fixmap_offset(FIX_P4D, addr);
1118 }
1119 
1120 static inline p4d_t *p4d_set_fixmap_offset(pgd_t *pgdp, unsigned long addr)
1121 {
1122 	if (!pgtable_l5_enabled())
1123 		return pgd_to_folded_p4d(pgdp, addr);
1124 	return p4d_set_fixmap(p4d_offset_phys(pgdp, addr));
1125 }
1126 
1127 static inline void p4d_clear_fixmap(void)
1128 {
1129 	if (pgtable_l5_enabled())
1130 		clear_fixmap(FIX_P4D);
1131 }
1132 
1133 /* use ONLY for statically allocated translation tables */
1134 static inline p4d_t *p4d_offset_kimg(pgd_t *pgdp, u64 addr)
1135 {
1136 	if (!pgtable_l5_enabled())
1137 		return pgd_to_folded_p4d(pgdp, addr);
1138 	return (p4d_t *)__phys_to_kimg(p4d_offset_phys(pgdp, addr));
1139 }
1140 
1141 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(__pgd_to_phys(pgd)))
1142 
1143 #else
1144 
1145 static inline bool pgtable_l5_enabled(void) { return false; }
1146 
1147 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1148 
1149 /* Match p4d_offset folding in <asm/generic/pgtable-nop4d.h> */
1150 #define p4d_set_fixmap(addr)		NULL
1151 #define p4d_set_fixmap_offset(p4dp, addr)	((p4d_t *)p4dp)
1152 #define p4d_clear_fixmap()
1153 
1154 #define p4d_offset_kimg(dir,addr)	((p4d_t *)dir)
1155 
1156 static inline
1157 p4d_t *p4d_offset_lockless_folded(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1158 {
1159 	/*
1160 	 * With runtime folding of the pud, pud_offset_lockless() passes
1161 	 * the 'pgd_t *' we return here to p4d_to_folded_pud(), which
1162 	 * will offset the pointer assuming that it points into
1163 	 * a page-table page. However, the fast GUP path passes us a
1164 	 * pgd_t allocated on the stack and so we must use the original
1165 	 * pointer in 'pgdp' to construct the p4d pointer instead of
1166 	 * using the generic p4d_offset_lockless() implementation.
1167 	 *
1168 	 * Note: reusing the original pointer means that we may
1169 	 * dereference the same (live) page-table entry multiple times.
1170 	 * This is safe because it is still only loaded once in the
1171 	 * context of each level and the CPU guarantees same-address
1172 	 * read-after-read ordering.
1173 	 */
1174 	return p4d_offset(pgdp, addr);
1175 }
1176 #define p4d_offset_lockless p4d_offset_lockless_folded
1177 
1178 #endif  /* CONFIG_PGTABLE_LEVELS > 4 */
1179 
1180 #define pgd_ERROR(e)	\
1181 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
1182 
1183 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
1184 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
1185 
1186 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
1187 {
1188 	/*
1189 	 * Normal and Normal-Tagged are two different memory types and indices
1190 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
1191 	 */
1192 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
1193 			      PTE_PRESENT_INVALID | PTE_VALID | PTE_WRITE |
1194 			      PTE_GP | PTE_ATTRINDX_MASK | PTE_PO_IDX_MASK;
1195 
1196 	/* preserve the hardware dirty information */
1197 	if (pte_hw_dirty(pte))
1198 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
1199 
1200 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
1201 	/*
1202 	 * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware
1203 	 * dirtiness again.
1204 	 */
1205 	if (pte_sw_dirty(pte))
1206 		pte = pte_mkdirty(pte);
1207 	return pte;
1208 }
1209 
1210 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1211 {
1212 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
1213 }
1214 
1215 extern int __ptep_set_access_flags(struct vm_area_struct *vma,
1216 				 unsigned long address, pte_t *ptep,
1217 				 pte_t entry, int dirty);
1218 
1219 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1220 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1221 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1222 					unsigned long address, pmd_t *pmdp,
1223 					pmd_t entry, int dirty)
1224 {
1225 	return __ptep_set_access_flags(vma, address, (pte_t *)pmdp,
1226 							pmd_pte(entry), dirty);
1227 }
1228 
1229 static inline int pud_devmap(pud_t pud)
1230 {
1231 	return 0;
1232 }
1233 
1234 static inline int pgd_devmap(pgd_t pgd)
1235 {
1236 	return 0;
1237 }
1238 #endif
1239 
1240 #ifdef CONFIG_PAGE_TABLE_CHECK
1241 static inline bool pte_user_accessible_page(pte_t pte)
1242 {
1243 	return pte_valid(pte) && (pte_user(pte) || pte_user_exec(pte));
1244 }
1245 
1246 static inline bool pmd_user_accessible_page(pmd_t pmd)
1247 {
1248 	return pmd_valid(pmd) && !pmd_table(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
1249 }
1250 
1251 static inline bool pud_user_accessible_page(pud_t pud)
1252 {
1253 	return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
1254 }
1255 #endif
1256 
1257 /*
1258  * Atomic pte/pmd modifications.
1259  */
1260 static inline int __ptep_test_and_clear_young(struct vm_area_struct *vma,
1261 					      unsigned long address,
1262 					      pte_t *ptep)
1263 {
1264 	pte_t old_pte, pte;
1265 
1266 	pte = __ptep_get(ptep);
1267 	do {
1268 		old_pte = pte;
1269 		pte = pte_mkold(pte);
1270 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1271 					       pte_val(old_pte), pte_val(pte));
1272 	} while (pte_val(pte) != pte_val(old_pte));
1273 
1274 	return pte_young(pte);
1275 }
1276 
1277 static inline int __ptep_clear_flush_young(struct vm_area_struct *vma,
1278 					 unsigned long address, pte_t *ptep)
1279 {
1280 	int young = __ptep_test_and_clear_young(vma, address, ptep);
1281 
1282 	if (young) {
1283 		/*
1284 		 * We can elide the trailing DSB here since the worst that can
1285 		 * happen is that a CPU continues to use the young entry in its
1286 		 * TLB and we mistakenly reclaim the associated page. The
1287 		 * window for such an event is bounded by the next
1288 		 * context-switch, which provides a DSB to complete the TLB
1289 		 * invalidation.
1290 		 */
1291 		flush_tlb_page_nosync(vma, address);
1292 	}
1293 
1294 	return young;
1295 }
1296 
1297 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
1298 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1299 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1300 					    unsigned long address,
1301 					    pmd_t *pmdp)
1302 {
1303 	/* Operation applies to PMD table entry only if FEAT_HAFT is enabled */
1304 	VM_WARN_ON(pmd_table(READ_ONCE(*pmdp)) && !system_supports_haft());
1305 	return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1306 }
1307 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
1308 
1309 static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
1310 				       unsigned long address, pte_t *ptep)
1311 {
1312 	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
1313 
1314 	page_table_check_pte_clear(mm, pte);
1315 
1316 	return pte;
1317 }
1318 
1319 static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1320 				pte_t *ptep, unsigned int nr, int full)
1321 {
1322 	for (;;) {
1323 		__ptep_get_and_clear(mm, addr, ptep);
1324 		if (--nr == 0)
1325 			break;
1326 		ptep++;
1327 		addr += PAGE_SIZE;
1328 	}
1329 }
1330 
1331 static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm,
1332 				unsigned long addr, pte_t *ptep,
1333 				unsigned int nr, int full)
1334 {
1335 	pte_t pte, tmp_pte;
1336 
1337 	pte = __ptep_get_and_clear(mm, addr, ptep);
1338 	while (--nr) {
1339 		ptep++;
1340 		addr += PAGE_SIZE;
1341 		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
1342 		if (pte_dirty(tmp_pte))
1343 			pte = pte_mkdirty(pte);
1344 		if (pte_young(tmp_pte))
1345 			pte = pte_mkyoung(pte);
1346 	}
1347 	return pte;
1348 }
1349 
1350 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1351 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1352 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1353 					    unsigned long address, pmd_t *pmdp)
1354 {
1355 	pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0));
1356 
1357 	page_table_check_pmd_clear(mm, pmd);
1358 
1359 	return pmd;
1360 }
1361 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1362 
1363 static inline void ___ptep_set_wrprotect(struct mm_struct *mm,
1364 					unsigned long address, pte_t *ptep,
1365 					pte_t pte)
1366 {
1367 	pte_t old_pte;
1368 
1369 	do {
1370 		old_pte = pte;
1371 		pte = pte_wrprotect(pte);
1372 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1373 					       pte_val(old_pte), pte_val(pte));
1374 	} while (pte_val(pte) != pte_val(old_pte));
1375 }
1376 
1377 /*
1378  * __ptep_set_wrprotect - mark read-only while transferring potential hardware
1379  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
1380  */
1381 static inline void __ptep_set_wrprotect(struct mm_struct *mm,
1382 					unsigned long address, pte_t *ptep)
1383 {
1384 	___ptep_set_wrprotect(mm, address, ptep, __ptep_get(ptep));
1385 }
1386 
1387 static inline void __wrprotect_ptes(struct mm_struct *mm, unsigned long address,
1388 				pte_t *ptep, unsigned int nr)
1389 {
1390 	unsigned int i;
1391 
1392 	for (i = 0; i < nr; i++, address += PAGE_SIZE, ptep++)
1393 		__ptep_set_wrprotect(mm, address, ptep);
1394 }
1395 
1396 static inline void __clear_young_dirty_pte(struct vm_area_struct *vma,
1397 					   unsigned long addr, pte_t *ptep,
1398 					   pte_t pte, cydp_t flags)
1399 {
1400 	pte_t old_pte;
1401 
1402 	do {
1403 		old_pte = pte;
1404 
1405 		if (flags & CYDP_CLEAR_YOUNG)
1406 			pte = pte_mkold(pte);
1407 		if (flags & CYDP_CLEAR_DIRTY)
1408 			pte = pte_mkclean(pte);
1409 
1410 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1411 					       pte_val(old_pte), pte_val(pte));
1412 	} while (pte_val(pte) != pte_val(old_pte));
1413 }
1414 
1415 static inline void __clear_young_dirty_ptes(struct vm_area_struct *vma,
1416 					    unsigned long addr, pte_t *ptep,
1417 					    unsigned int nr, cydp_t flags)
1418 {
1419 	pte_t pte;
1420 
1421 	for (;;) {
1422 		pte = __ptep_get(ptep);
1423 
1424 		if (flags == (CYDP_CLEAR_YOUNG | CYDP_CLEAR_DIRTY))
1425 			__set_pte(ptep, pte_mkclean(pte_mkold(pte)));
1426 		else
1427 			__clear_young_dirty_pte(vma, addr, ptep, pte, flags);
1428 
1429 		if (--nr == 0)
1430 			break;
1431 		ptep++;
1432 		addr += PAGE_SIZE;
1433 	}
1434 }
1435 
1436 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1437 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1438 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1439 				      unsigned long address, pmd_t *pmdp)
1440 {
1441 	__ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1442 }
1443 
1444 #define pmdp_establish pmdp_establish
1445 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1446 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
1447 {
1448 	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
1449 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
1450 }
1451 #endif
1452 
1453 /*
1454  * Encode and decode a swap entry:
1455  *	bits 0-1:	present (must be zero)
1456  *	bits 2:		remember PG_anon_exclusive
1457  *	bit  3:		remember uffd-wp state
1458  *	bits 6-10:	swap type
1459  *	bit  11:	PTE_PRESENT_INVALID (must be zero)
1460  *	bits 12-61:	swap offset
1461  */
1462 #define __SWP_TYPE_SHIFT	6
1463 #define __SWP_TYPE_BITS		5
1464 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
1465 #define __SWP_OFFSET_SHIFT	12
1466 #define __SWP_OFFSET_BITS	50
1467 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
1468 
1469 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1470 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
1471 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
1472 
1473 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1474 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
1475 
1476 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1477 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
1478 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
1479 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
1480 
1481 /*
1482  * Ensure that there are not more swap files than can be encoded in the kernel
1483  * PTEs.
1484  */
1485 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1486 
1487 #ifdef CONFIG_ARM64_MTE
1488 
1489 #define __HAVE_ARCH_PREPARE_TO_SWAP
1490 extern int arch_prepare_to_swap(struct folio *folio);
1491 
1492 #define __HAVE_ARCH_SWAP_INVALIDATE
1493 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
1494 {
1495 	if (system_supports_mte())
1496 		mte_invalidate_tags(type, offset);
1497 }
1498 
1499 static inline void arch_swap_invalidate_area(int type)
1500 {
1501 	if (system_supports_mte())
1502 		mte_invalidate_tags_area(type);
1503 }
1504 
1505 #define __HAVE_ARCH_SWAP_RESTORE
1506 extern void arch_swap_restore(swp_entry_t entry, struct folio *folio);
1507 
1508 #endif /* CONFIG_ARM64_MTE */
1509 
1510 /*
1511  * On AArch64, the cache coherency is handled via the __set_ptes() function.
1512  */
1513 static inline void update_mmu_cache_range(struct vm_fault *vmf,
1514 		struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
1515 		unsigned int nr)
1516 {
1517 	/*
1518 	 * We don't do anything here, so there's a very small chance of
1519 	 * us retaking a user fault which we just fixed up. The alternative
1520 	 * is doing a dsb(ishst), but that penalises the fastpath.
1521 	 */
1522 }
1523 
1524 #define update_mmu_cache(vma, addr, ptep) \
1525 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
1526 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
1527 
1528 #ifdef CONFIG_ARM64_PA_BITS_52
1529 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
1530 #else
1531 #define phys_to_ttbr(addr)	(addr)
1532 #endif
1533 
1534 /*
1535  * On arm64 without hardware Access Flag, copying from user will fail because
1536  * the pte is old and cannot be marked young. So we always end up with zeroed
1537  * page after fork() + CoW for pfn mappings. We don't always have a
1538  * hardware-managed access flag on arm64.
1539  */
1540 #define arch_has_hw_pte_young		cpu_has_hw_af
1541 
1542 #ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
1543 #define arch_has_hw_nonleaf_pmd_young	system_supports_haft
1544 #endif
1545 
1546 /*
1547  * Experimentally, it's cheap to set the access flag in hardware and we
1548  * benefit from prefaulting mappings as 'old' to start with.
1549  */
1550 #define arch_wants_old_prefaulted_pte	cpu_has_hw_af
1551 
1552 static inline bool pud_sect_supported(void)
1553 {
1554 	return PAGE_SIZE == SZ_4K;
1555 }
1556 
1557 
1558 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1559 #define ptep_modify_prot_start ptep_modify_prot_start
1560 extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
1561 				    unsigned long addr, pte_t *ptep);
1562 
1563 #define ptep_modify_prot_commit ptep_modify_prot_commit
1564 extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
1565 				    unsigned long addr, pte_t *ptep,
1566 				    pte_t old_pte, pte_t new_pte);
1567 
1568 #ifdef CONFIG_ARM64_CONTPTE
1569 
1570 /*
1571  * The contpte APIs are used to transparently manage the contiguous bit in ptes
1572  * where it is possible and makes sense to do so. The PTE_CONT bit is considered
1573  * a private implementation detail of the public ptep API (see below).
1574  */
1575 extern void __contpte_try_fold(struct mm_struct *mm, unsigned long addr,
1576 				pte_t *ptep, pte_t pte);
1577 extern void __contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
1578 				pte_t *ptep, pte_t pte);
1579 extern pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte);
1580 extern pte_t contpte_ptep_get_lockless(pte_t *orig_ptep);
1581 extern void contpte_set_ptes(struct mm_struct *mm, unsigned long addr,
1582 				pte_t *ptep, pte_t pte, unsigned int nr);
1583 extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1584 				pte_t *ptep, unsigned int nr, int full);
1585 extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
1586 				unsigned long addr, pte_t *ptep,
1587 				unsigned int nr, int full);
1588 extern int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma,
1589 				unsigned long addr, pte_t *ptep);
1590 extern int contpte_ptep_clear_flush_young(struct vm_area_struct *vma,
1591 				unsigned long addr, pte_t *ptep);
1592 extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
1593 				pte_t *ptep, unsigned int nr);
1594 extern int contpte_ptep_set_access_flags(struct vm_area_struct *vma,
1595 				unsigned long addr, pte_t *ptep,
1596 				pte_t entry, int dirty);
1597 extern void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,
1598 				unsigned long addr, pte_t *ptep,
1599 				unsigned int nr, cydp_t flags);
1600 
1601 static __always_inline void contpte_try_fold(struct mm_struct *mm,
1602 				unsigned long addr, pte_t *ptep, pte_t pte)
1603 {
1604 	/*
1605 	 * Only bother trying if both the virtual and physical addresses are
1606 	 * aligned and correspond to the last entry in a contig range. The core
1607 	 * code mostly modifies ranges from low to high, so this is the likely
1608 	 * the last modification in the contig range, so a good time to fold.
1609 	 * We can't fold special mappings, because there is no associated folio.
1610 	 */
1611 
1612 	const unsigned long contmask = CONT_PTES - 1;
1613 	bool valign = ((addr >> PAGE_SHIFT) & contmask) == contmask;
1614 
1615 	if (unlikely(valign)) {
1616 		bool palign = (pte_pfn(pte) & contmask) == contmask;
1617 
1618 		if (unlikely(palign &&
1619 		    pte_valid(pte) && !pte_cont(pte) && !pte_special(pte)))
1620 			__contpte_try_fold(mm, addr, ptep, pte);
1621 	}
1622 }
1623 
1624 static __always_inline void contpte_try_unfold(struct mm_struct *mm,
1625 				unsigned long addr, pte_t *ptep, pte_t pte)
1626 {
1627 	if (unlikely(pte_valid_cont(pte)))
1628 		__contpte_try_unfold(mm, addr, ptep, pte);
1629 }
1630 
1631 #define pte_batch_hint pte_batch_hint
1632 static inline unsigned int pte_batch_hint(pte_t *ptep, pte_t pte)
1633 {
1634 	if (!pte_valid_cont(pte))
1635 		return 1;
1636 
1637 	return CONT_PTES - (((unsigned long)ptep >> 3) & (CONT_PTES - 1));
1638 }
1639 
1640 /*
1641  * The below functions constitute the public API that arm64 presents to the
1642  * core-mm to manipulate PTE entries within their page tables (or at least this
1643  * is the subset of the API that arm64 needs to implement). These public
1644  * versions will automatically and transparently apply the contiguous bit where
1645  * it makes sense to do so. Therefore any users that are contig-aware (e.g.
1646  * hugetlb, kernel mapper) should NOT use these APIs, but instead use the
1647  * private versions, which are prefixed with double underscore. All of these
1648  * APIs except for ptep_get_lockless() are expected to be called with the PTL
1649  * held. Although the contiguous bit is considered private to the
1650  * implementation, it is deliberately allowed to leak through the getters (e.g.
1651  * ptep_get()), back to core code. This is required so that pte_leaf_size() can
1652  * provide an accurate size for perf_get_pgtable_size(). But this leakage means
1653  * its possible a pte will be passed to a setter with the contiguous bit set, so
1654  * we explicitly clear the contiguous bit in those cases to prevent accidentally
1655  * setting it in the pgtable.
1656  */
1657 
1658 #define ptep_get ptep_get
1659 static inline pte_t ptep_get(pte_t *ptep)
1660 {
1661 	pte_t pte = __ptep_get(ptep);
1662 
1663 	if (likely(!pte_valid_cont(pte)))
1664 		return pte;
1665 
1666 	return contpte_ptep_get(ptep, pte);
1667 }
1668 
1669 #define ptep_get_lockless ptep_get_lockless
1670 static inline pte_t ptep_get_lockless(pte_t *ptep)
1671 {
1672 	pte_t pte = __ptep_get(ptep);
1673 
1674 	if (likely(!pte_valid_cont(pte)))
1675 		return pte;
1676 
1677 	return contpte_ptep_get_lockless(ptep);
1678 }
1679 
1680 static inline void set_pte(pte_t *ptep, pte_t pte)
1681 {
1682 	/*
1683 	 * We don't have the mm or vaddr so cannot unfold contig entries (since
1684 	 * it requires tlb maintenance). set_pte() is not used in core code, so
1685 	 * this should never even be called. Regardless do our best to service
1686 	 * any call and emit a warning if there is any attempt to set a pte on
1687 	 * top of an existing contig range.
1688 	 */
1689 	pte_t orig_pte = __ptep_get(ptep);
1690 
1691 	WARN_ON_ONCE(pte_valid_cont(orig_pte));
1692 	__set_pte(ptep, pte_mknoncont(pte));
1693 }
1694 
1695 #define set_ptes set_ptes
1696 static __always_inline void set_ptes(struct mm_struct *mm, unsigned long addr,
1697 				pte_t *ptep, pte_t pte, unsigned int nr)
1698 {
1699 	pte = pte_mknoncont(pte);
1700 
1701 	if (likely(nr == 1)) {
1702 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1703 		__set_ptes(mm, addr, ptep, pte, 1);
1704 		contpte_try_fold(mm, addr, ptep, pte);
1705 	} else {
1706 		contpte_set_ptes(mm, addr, ptep, pte, nr);
1707 	}
1708 }
1709 
1710 static inline void pte_clear(struct mm_struct *mm,
1711 				unsigned long addr, pte_t *ptep)
1712 {
1713 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1714 	__pte_clear(mm, addr, ptep);
1715 }
1716 
1717 #define clear_full_ptes clear_full_ptes
1718 static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1719 				pte_t *ptep, unsigned int nr, int full)
1720 {
1721 	if (likely(nr == 1)) {
1722 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1723 		__clear_full_ptes(mm, addr, ptep, nr, full);
1724 	} else {
1725 		contpte_clear_full_ptes(mm, addr, ptep, nr, full);
1726 	}
1727 }
1728 
1729 #define get_and_clear_full_ptes get_and_clear_full_ptes
1730 static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm,
1731 				unsigned long addr, pte_t *ptep,
1732 				unsigned int nr, int full)
1733 {
1734 	pte_t pte;
1735 
1736 	if (likely(nr == 1)) {
1737 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1738 		pte = __get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1739 	} else {
1740 		pte = contpte_get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1741 	}
1742 
1743 	return pte;
1744 }
1745 
1746 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1747 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1748 				unsigned long addr, pte_t *ptep)
1749 {
1750 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1751 	return __ptep_get_and_clear(mm, addr, ptep);
1752 }
1753 
1754 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1755 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
1756 				unsigned long addr, pte_t *ptep)
1757 {
1758 	pte_t orig_pte = __ptep_get(ptep);
1759 
1760 	if (likely(!pte_valid_cont(orig_pte)))
1761 		return __ptep_test_and_clear_young(vma, addr, ptep);
1762 
1763 	return contpte_ptep_test_and_clear_young(vma, addr, ptep);
1764 }
1765 
1766 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1767 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
1768 				unsigned long addr, pte_t *ptep)
1769 {
1770 	pte_t orig_pte = __ptep_get(ptep);
1771 
1772 	if (likely(!pte_valid_cont(orig_pte)))
1773 		return __ptep_clear_flush_young(vma, addr, ptep);
1774 
1775 	return contpte_ptep_clear_flush_young(vma, addr, ptep);
1776 }
1777 
1778 #define wrprotect_ptes wrprotect_ptes
1779 static __always_inline void wrprotect_ptes(struct mm_struct *mm,
1780 				unsigned long addr, pte_t *ptep, unsigned int nr)
1781 {
1782 	if (likely(nr == 1)) {
1783 		/*
1784 		 * Optimization: wrprotect_ptes() can only be called for present
1785 		 * ptes so we only need to check contig bit as condition for
1786 		 * unfold, and we can remove the contig bit from the pte we read
1787 		 * to avoid re-reading. This speeds up fork() which is sensitive
1788 		 * for order-0 folios. Equivalent to contpte_try_unfold().
1789 		 */
1790 		pte_t orig_pte = __ptep_get(ptep);
1791 
1792 		if (unlikely(pte_cont(orig_pte))) {
1793 			__contpte_try_unfold(mm, addr, ptep, orig_pte);
1794 			orig_pte = pte_mknoncont(orig_pte);
1795 		}
1796 		___ptep_set_wrprotect(mm, addr, ptep, orig_pte);
1797 	} else {
1798 		contpte_wrprotect_ptes(mm, addr, ptep, nr);
1799 	}
1800 }
1801 
1802 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1803 static inline void ptep_set_wrprotect(struct mm_struct *mm,
1804 				unsigned long addr, pte_t *ptep)
1805 {
1806 	wrprotect_ptes(mm, addr, ptep, 1);
1807 }
1808 
1809 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1810 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1811 				unsigned long addr, pte_t *ptep,
1812 				pte_t entry, int dirty)
1813 {
1814 	pte_t orig_pte = __ptep_get(ptep);
1815 
1816 	entry = pte_mknoncont(entry);
1817 
1818 	if (likely(!pte_valid_cont(orig_pte)))
1819 		return __ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1820 
1821 	return contpte_ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1822 }
1823 
1824 #define clear_young_dirty_ptes clear_young_dirty_ptes
1825 static inline void clear_young_dirty_ptes(struct vm_area_struct *vma,
1826 					  unsigned long addr, pte_t *ptep,
1827 					  unsigned int nr, cydp_t flags)
1828 {
1829 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
1830 		__clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1831 	else
1832 		contpte_clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1833 }
1834 
1835 #else /* CONFIG_ARM64_CONTPTE */
1836 
1837 #define ptep_get				__ptep_get
1838 #define set_pte					__set_pte
1839 #define set_ptes				__set_ptes
1840 #define pte_clear				__pte_clear
1841 #define clear_full_ptes				__clear_full_ptes
1842 #define get_and_clear_full_ptes			__get_and_clear_full_ptes
1843 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1844 #define ptep_get_and_clear			__ptep_get_and_clear
1845 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1846 #define ptep_test_and_clear_young		__ptep_test_and_clear_young
1847 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1848 #define ptep_clear_flush_young			__ptep_clear_flush_young
1849 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1850 #define ptep_set_wrprotect			__ptep_set_wrprotect
1851 #define wrprotect_ptes				__wrprotect_ptes
1852 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1853 #define ptep_set_access_flags			__ptep_set_access_flags
1854 #define clear_young_dirty_ptes			__clear_young_dirty_ptes
1855 
1856 #endif /* CONFIG_ARM64_CONTPTE */
1857 
1858 #endif /* !__ASSEMBLY__ */
1859 
1860 #endif /* __ASM_PGTABLE_H */
1861