xref: /linux/arch/arm64/include/asm/pgtable.h (revision 93d23dff8eb5045a9cb54bf6202324da0c7010cb)
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 __ASSEMBLER__
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 static inline void emit_pte_barriers(void)
44 {
45 	/*
46 	 * These barriers are emitted under certain conditions after a pte entry
47 	 * was modified (see e.g. __set_pte_complete()). The dsb makes the store
48 	 * visible to the table walker. The isb ensures that any previous
49 	 * speculative "invalid translation" marker that is in the CPU's
50 	 * pipeline gets cleared, so that any access to that address after
51 	 * setting the pte to valid won't cause a spurious fault. If the thread
52 	 * gets preempted after storing to the pgtable but before emitting these
53 	 * barriers, __switch_to() emits a dsb which ensure the walker gets to
54 	 * see the store. There is no guarantee of an isb being issued though.
55 	 * This is safe because it will still get issued (albeit on a
56 	 * potentially different CPU) when the thread starts running again,
57 	 * before any access to the address.
58 	 */
59 	dsb(ishst);
60 	isb();
61 }
62 
63 static inline void queue_pte_barriers(void)
64 {
65 	if (is_lazy_mmu_mode_active()) {
66 		/* Avoid the atomic op if already set. */
67 		if (!test_thread_flag(TIF_LAZY_MMU_PENDING))
68 			set_thread_flag(TIF_LAZY_MMU_PENDING);
69 	} else {
70 		emit_pte_barriers();
71 	}
72 }
73 
74 static inline void arch_enter_lazy_mmu_mode(void) {}
75 
76 static inline void arch_flush_lazy_mmu_mode(void)
77 {
78 	if (test_and_clear_thread_flag(TIF_LAZY_MMU_PENDING))
79 		emit_pte_barriers();
80 }
81 
82 static inline void arch_leave_lazy_mmu_mode(void)
83 {
84 	arch_flush_lazy_mmu_mode();
85 }
86 
87 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
88 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
89 
90 /* Set stride and tlb_level in flush_*_tlb_range */
91 #define flush_pmd_tlb_range(vma, addr, end)	\
92 	__flush_tlb_range(vma, addr, end, PMD_SIZE, 2, TLBF_NONE)
93 #define flush_pud_tlb_range(vma, addr, end)	\
94 	__flush_tlb_range(vma, addr, end, PUD_SIZE, 1, TLBF_NONE)
95 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
96 
97 /*
98  * We use local TLB invalidation instruction when reusing page in
99  * write protection fault handler to avoid TLBI broadcast in the hot
100  * path.  This will cause spurious page faults if stale read-only TLB
101  * entries exist.
102  */
103 #define flush_tlb_fix_spurious_fault(vma, address, ptep)	\
104 	__flush_tlb_page(vma, address, TLBF_NOBROADCAST | TLBF_NONOTIFY)
105 
106 #define flush_tlb_fix_spurious_fault_pmd(vma, address, pmdp)			\
107 	__flush_tlb_range(vma, address, address + PMD_SIZE, PMD_SIZE, 2,	\
108 			  TLBF_NOBROADCAST | TLBF_NONOTIFY | TLBF_NOWALKCACHE)
109 
110 #define pte_ERROR(e)	\
111 	pr_err("%s:%d: bad pte %016llx.\n", __FILE__, __LINE__, pte_val(e))
112 
113 #ifdef CONFIG_ARM64_PA_BITS_52
114 static inline phys_addr_t __pte_to_phys(pte_t pte)
115 {
116 	pte_val(pte) &= ~PTE_MAYBE_SHARED;
117 	return (pte_val(pte) & PTE_ADDR_LOW) |
118 		((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT);
119 }
120 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
121 {
122 	return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PHYS_TO_PTE_ADDR_MASK;
123 }
124 #else
125 static inline phys_addr_t __pte_to_phys(pte_t pte)
126 {
127 	return pte_val(pte) & PTE_ADDR_LOW;
128 }
129 
130 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
131 {
132 	return phys;
133 }
134 #endif
135 
136 #define pte_pfn(pte)		(__pte_to_phys(pte) >> PAGE_SHIFT)
137 #define pfn_pte(pfn,prot)	\
138 	__pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
139 
140 #define pte_none(pte)		(!pte_val(pte))
141 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
142 
143 /*
144  * The following only work if pte_present(). Undefined behaviour otherwise.
145  */
146 #define pte_present(pte)	(pte_valid(pte) || pte_present_invalid(pte))
147 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
148 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
149 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
150 #define pte_rdonly(pte)		(!!(pte_val(pte) & PTE_RDONLY))
151 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
152 #define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
153 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
154 #define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \
155 				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
156 
157 #define pte_cont_addr_end(addr, end)						\
158 ({	unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;	\
159 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
160 })
161 
162 #define pmd_cont_addr_end(addr, end)						\
163 ({	unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;	\
164 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
165 })
166 
167 #define pte_hw_dirty(pte)	(pte_write(pte) && !pte_rdonly(pte))
168 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
169 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
170 
171 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
172 #define pte_present_invalid(pte) \
173 	((pte_val(pte) & (PTE_VALID | PTE_PRESENT_INVALID)) == PTE_PRESENT_INVALID)
174 /*
175  * Execute-only user mappings do not have the PTE_USER bit set. All valid
176  * kernel mappings have the PTE_UXN bit set.
177  */
178 #define pte_valid_not_user(pte) \
179 	((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
180 /*
181  * Returns true if the pte is valid and has the contiguous bit set.
182  */
183 #define pte_valid_cont(pte)	(pte_valid(pte) && pte_cont(pte))
184 /*
185  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
186  * so that we don't erroneously return false for pages that have been
187  * remapped as PROT_NONE but are yet to be flushed from the TLB.
188  * Note that we can't make any assumptions based on the state of the access
189  * flag, since __ptep_clear_flush_young() elides a DSB when invalidating the
190  * TLB.
191  */
192 #define pte_accessible(mm, pte)	\
193 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
194 
195 static inline bool por_el0_allows_pkey(u8 pkey, bool write, bool execute)
196 {
197 	u64 por;
198 
199 	if (!system_supports_poe())
200 		return true;
201 
202 	por = read_sysreg_s(SYS_POR_EL0);
203 
204 	if (write)
205 		return por_elx_allows_write(por, pkey);
206 
207 	if (execute)
208 		return por_elx_allows_exec(por, pkey);
209 
210 	return por_elx_allows_read(por, pkey);
211 }
212 
213 /*
214  * p??_access_permitted() is true for valid user mappings (PTE_USER
215  * bit set, subject to the write permission check). For execute-only
216  * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits
217  * not set) must return false. PROT_NONE mappings do not have the
218  * PTE_VALID bit set.
219  */
220 #define pte_access_permitted_no_overlay(pte, write) \
221 	(((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte)))
222 #define pte_access_permitted(pte, write) \
223 	(pte_access_permitted_no_overlay(pte, write) && \
224 	por_el0_allows_pkey(FIELD_GET(PTE_PO_IDX_MASK, pte_val(pte)), write, false))
225 #define pmd_access_permitted(pmd, write) \
226 	(pte_access_permitted(pmd_pte(pmd), (write)))
227 #define pud_access_permitted(pud, write) \
228 	(pte_access_permitted(pud_pte(pud), (write)))
229 
230 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
231 {
232 	pte_val(pte) &= ~pgprot_val(prot);
233 	return pte;
234 }
235 
236 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
237 {
238 	pte_val(pte) |= pgprot_val(prot);
239 	return pte;
240 }
241 
242 static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t prot)
243 {
244 	pmd_val(pmd) &= ~pgprot_val(prot);
245 	return pmd;
246 }
247 
248 static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot)
249 {
250 	pmd_val(pmd) |= pgprot_val(prot);
251 	return pmd;
252 }
253 
254 static inline pte_t pte_mkwrite_novma(pte_t pte)
255 {
256 	pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
257 	if (pte_sw_dirty(pte))
258 		pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
259 	return pte;
260 }
261 
262 static inline pte_t pte_mkclean(pte_t pte)
263 {
264 	pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
265 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
266 
267 	return pte;
268 }
269 
270 static inline pte_t pte_mkdirty(pte_t pte)
271 {
272 	pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
273 
274 	if (pte_write(pte))
275 		pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
276 
277 	return pte;
278 }
279 
280 static inline pte_t pte_wrprotect(pte_t pte)
281 {
282 	/*
283 	 * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
284 	 * clear), set the PTE_DIRTY bit.
285 	 */
286 	if (pte_hw_dirty(pte))
287 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
288 
289 	pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
290 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
291 	return pte;
292 }
293 
294 static inline pte_t pte_mkold(pte_t pte)
295 {
296 	return clear_pte_bit(pte, __pgprot(PTE_AF));
297 }
298 
299 static inline pte_t pte_mkyoung(pte_t pte)
300 {
301 	return set_pte_bit(pte, __pgprot(PTE_AF));
302 }
303 
304 static inline pte_t pte_mkspecial(pte_t pte)
305 {
306 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
307 }
308 
309 static inline pte_t pte_mkcont(pte_t pte)
310 {
311 	return set_pte_bit(pte, __pgprot(PTE_CONT));
312 }
313 
314 static inline pte_t pte_mknoncont(pte_t pte)
315 {
316 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
317 }
318 
319 static inline pte_t pte_mkvalid_k(pte_t pte)
320 {
321 	pte = clear_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID));
322 	pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_VALID_KERNEL));
323 	return pte;
324 }
325 
326 static inline pte_t pte_mkinvalid(pte_t pte)
327 {
328 	pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID));
329 	pte = clear_pte_bit(pte, __pgprot(PTE_VALID));
330 	return pte;
331 }
332 
333 static inline pmd_t pmd_mkcont(pmd_t pmd)
334 {
335 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
336 }
337 
338 static inline pmd_t pmd_mknoncont(pmd_t pmd)
339 {
340 	return __pmd(pmd_val(pmd) & ~PMD_SECT_CONT);
341 }
342 
343 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
344 static inline int pte_uffd(pte_t pte)
345 {
346 	return !!(pte_val(pte) & PTE_UFFD);
347 }
348 
349 static inline pte_t pte_mkuffd(pte_t pte)
350 {
351 	return pte_wrprotect(set_pte_bit(pte, __pgprot(PTE_UFFD)));
352 }
353 
354 static inline pte_t pte_clear_uffd(pte_t pte)
355 {
356 	return clear_pte_bit(pte, __pgprot(PTE_UFFD));
357 }
358 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
359 
360 static inline void __set_pte_nosync(pte_t *ptep, pte_t pte)
361 {
362 	WRITE_ONCE(*ptep, pte);
363 }
364 
365 static inline void __set_pte_complete(pte_t pte)
366 {
367 	/*
368 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
369 	 * has the necessary barriers.
370 	 */
371 	if (pte_valid_not_user(pte))
372 		queue_pte_barriers();
373 }
374 
375 static inline void __set_pte(pte_t *ptep, pte_t pte)
376 {
377 	__set_pte_nosync(ptep, pte);
378 	__set_pte_complete(pte);
379 }
380 
381 static inline pte_t __ptep_get(pte_t *ptep)
382 {
383 	return READ_ONCE(*ptep);
384 }
385 
386 extern void __sync_icache_dcache(pte_t pteval);
387 bool pgattr_change_is_safe(pteval_t old, pteval_t new);
388 
389 /*
390  * PTE bits configuration in the presence of hardware Dirty Bit Management
391  * (PTE_WRITE == PTE_DBM):
392  *
393  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
394  *   0      0      |   1           0          0
395  *   0      1      |   1           1          0
396  *   1      0      |   1           0          1
397  *   1      1      |   0           1          x
398  *
399  * When hardware DBM is not present, the software PTE_DIRTY bit is updated via
400  * the page fault mechanism. Checking the dirty status of a pte becomes:
401  *
402  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
403  */
404 
405 static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep,
406 					   pte_t pte)
407 {
408 	pte_t old_pte;
409 
410 	if (!IS_ENABLED(CONFIG_DEBUG_VM))
411 		return;
412 
413 	old_pte = __ptep_get(ptep);
414 
415 	if (!pte_valid(old_pte) || !pte_valid(pte))
416 		return;
417 	if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1)
418 		return;
419 
420 	/*
421 	 * Check for potential race with hardware updates of the pte
422 	 * (__ptep_set_access_flags safely changes valid ptes without going
423 	 * through an invalid entry).
424 	 */
425 	VM_WARN_ONCE(!pte_young(pte),
426 		     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
427 		     __func__, pte_val(old_pte), pte_val(pte));
428 	VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte),
429 		     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
430 		     __func__, pte_val(old_pte), pte_val(pte));
431 	VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)),
432 		     "%s: unsafe attribute change: 0x%016llx -> 0x%016llx",
433 		     __func__, pte_val(old_pte), pte_val(pte));
434 }
435 
436 static inline void __sync_cache_and_tags(pte_t pte, unsigned int nr_pages)
437 {
438 	if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
439 		__sync_icache_dcache(pte);
440 
441 	/*
442 	 * If the PTE would provide user space access to the tags associated
443 	 * with it then ensure that the MTE tags are synchronised.  Although
444 	 * pte_access_permitted_no_overlay() returns false for exec only
445 	 * mappings, they don't expose tags (instruction fetches don't check
446 	 * tags).
447 	 */
448 	if (system_supports_mte() && pte_access_permitted_no_overlay(pte, false) &&
449 	    !pte_special(pte) && pte_tagged(pte))
450 		mte_sync_tags(pte, nr_pages);
451 }
452 
453 /*
454  * Select all bits except the pfn
455  */
456 #define pte_pgprot pte_pgprot
457 static inline pgprot_t pte_pgprot(pte_t pte)
458 {
459 	unsigned long pfn = pte_pfn(pte);
460 
461 	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
462 }
463 
464 #define pte_advance_pfn pte_advance_pfn
465 static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr)
466 {
467 	return pfn_pte(pte_pfn(pte) + nr, pte_pgprot(pte));
468 }
469 
470 /*
471  * Hugetlb definitions.
472  */
473 #define HUGE_MAX_HSTATE		4
474 #define HPAGE_SHIFT		PMD_SHIFT
475 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
476 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
477 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
478 
479 static inline pte_t pgd_pte(pgd_t pgd)
480 {
481 	return __pte(pgd_val(pgd));
482 }
483 
484 static inline pte_t p4d_pte(p4d_t p4d)
485 {
486 	return __pte(p4d_val(p4d));
487 }
488 
489 static inline pte_t pud_pte(pud_t pud)
490 {
491 	return __pte(pud_val(pud));
492 }
493 
494 static inline pud_t pte_pud(pte_t pte)
495 {
496 	return __pud(pte_val(pte));
497 }
498 
499 static inline pmd_t pud_pmd(pud_t pud)
500 {
501 	return __pmd(pud_val(pud));
502 }
503 
504 static inline pte_t pmd_pte(pmd_t pmd)
505 {
506 	return __pte(pmd_val(pmd));
507 }
508 
509 static inline pmd_t pte_pmd(pte_t pte)
510 {
511 	return __pmd(pte_val(pte));
512 }
513 
514 static inline pgprot_t mk_pud_sect_prot(pgprot_t prot)
515 {
516 	return __pgprot((pgprot_val(prot) & ~PUD_TYPE_MASK) | PUD_TYPE_SECT);
517 }
518 
519 static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot)
520 {
521 	return __pgprot((pgprot_val(prot) & ~PMD_TYPE_MASK) | PMD_TYPE_SECT);
522 }
523 
524 static inline pte_t pte_swp_mkexclusive(pte_t pte)
525 {
526 	return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
527 }
528 
529 static inline bool pte_swp_exclusive(pte_t pte)
530 {
531 	return pte_val(pte) & PTE_SWP_EXCLUSIVE;
532 }
533 
534 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
535 {
536 	return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
537 }
538 
539 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
540 static inline pte_t pte_swp_mkuffd(pte_t pte)
541 {
542 	return set_pte_bit(pte, __pgprot(PTE_SWP_UFFD));
543 }
544 
545 static inline int pte_swp_uffd(pte_t pte)
546 {
547 	return !!(pte_val(pte) & PTE_SWP_UFFD);
548 }
549 
550 static inline pte_t pte_swp_clear_uffd(pte_t pte)
551 {
552 	return clear_pte_bit(pte, __pgprot(PTE_SWP_UFFD));
553 }
554 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
555 
556 #ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
557 static inline int pte_protnone(pte_t pte)
558 {
559 	/*
560 	 * pte_present_invalid() tells us that the pte is invalid from HW
561 	 * perspective but present from SW perspective, so the fields are to be
562 	 * interpreted as per the HW layout. The second 2 checks are the unique
563 	 * encoding that we use for PROT_NONE. It is insufficient to only use
564 	 * the first check because we share the same encoding scheme with pmds
565 	 * which support pmd_mkinvalid(), so can be present-invalid without
566 	 * being PROT_NONE.
567 	 */
568 	return pte_present_invalid(pte) && !pte_user(pte) && !pte_user_exec(pte);
569 }
570 
571 static inline int pmd_protnone(pmd_t pmd)
572 {
573 	return pte_protnone(pmd_pte(pmd));
574 }
575 #endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
576 
577 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
578 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
579 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
580 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
581 #define pmd_user(pmd)		pte_user(pmd_pte(pmd))
582 #define pmd_user_exec(pmd)	pte_user_exec(pmd_pte(pmd))
583 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
584 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
585 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
586 #define pmd_mkwrite_novma(pmd)	pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)))
587 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
588 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
589 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
590 #define pmd_mkvalid_k(pmd)	pte_pmd(pte_mkvalid_k(pmd_pte(pmd)))
591 #define pmd_mkinvalid(pmd)	pte_pmd(pte_mkinvalid(pmd_pte(pmd)))
592 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
593 #define pmd_uffd(pmd)	pte_uffd(pmd_pte(pmd))
594 #define pmd_mkuffd(pmd)	pte_pmd(pte_mkuffd(pmd_pte(pmd)))
595 #define pmd_clear_uffd(pmd)	pte_pmd(pte_clear_uffd(pmd_pte(pmd)))
596 #define pmd_swp_uffd(pmd)	pte_swp_uffd(pmd_pte(pmd))
597 #define pmd_swp_mkuffd(pmd)	pte_pmd(pte_swp_mkuffd(pmd_pte(pmd)))
598 #define pmd_swp_clear_uffd(pmd) \
599 				pte_pmd(pte_swp_clear_uffd(pmd_pte(pmd)))
600 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
601 
602 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
603 
604 static inline pmd_t pmd_mkhuge(pmd_t pmd)
605 {
606 	/*
607 	 * It's possible that the pmd is present-invalid on entry
608 	 * and in that case it needs to remain present-invalid on
609 	 * exit. So ensure the VALID bit does not get modified.
610 	 */
611 	pmdval_t mask = PMD_TYPE_MASK & ~PTE_VALID;
612 	pmdval_t val = PMD_TYPE_SECT & ~PTE_VALID;
613 
614 	return __pmd((pmd_val(pmd) & ~mask) | val);
615 }
616 
617 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
618 #define pmd_special(pte)	(!!((pmd_val(pte) & PTE_SPECIAL)))
619 static inline pmd_t pmd_mkspecial(pmd_t pmd)
620 {
621 	return set_pmd_bit(pmd, __pgprot(PTE_SPECIAL));
622 }
623 #endif
624 
625 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
626 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
627 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
628 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
629 
630 #define pud_young(pud)		pte_young(pud_pte(pud))
631 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
632 #define pud_mkwrite_novma(pud)	pte_pud(pte_mkwrite_novma(pud_pte(pud)))
633 #define pud_mkvalid_k(pud)	pte_pud(pte_mkvalid_k(pud_pte(pud)))
634 #define pud_write(pud)		pte_write(pud_pte(pud))
635 
636 static inline pud_t pud_mkhuge(pud_t pud)
637 {
638 	/*
639 	 * It's possible that the pud is present-invalid on entry
640 	 * and in that case it needs to remain present-invalid on
641 	 * exit. So ensure the VALID bit does not get modified.
642 	 */
643 	pudval_t mask = PUD_TYPE_MASK & ~PTE_VALID;
644 	pudval_t val = PUD_TYPE_SECT & ~PTE_VALID;
645 
646 	return __pud((pud_val(pud) & ~mask) | val);
647 }
648 
649 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
650 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
651 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
652 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
653 
654 #define pmd_pgprot pmd_pgprot
655 static inline pgprot_t pmd_pgprot(pmd_t pmd)
656 {
657 	unsigned long pfn = pmd_pfn(pmd);
658 
659 	return __pgprot(pmd_val(pfn_pmd(pfn, __pgprot(0))) ^ pmd_val(pmd));
660 }
661 
662 #define pud_pgprot pud_pgprot
663 static inline pgprot_t pud_pgprot(pud_t pud)
664 {
665 	unsigned long pfn = pud_pfn(pud);
666 
667 	return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud));
668 }
669 
670 static inline void __set_ptes_anysz(struct mm_struct *mm, unsigned long addr,
671 				    pte_t *ptep, pte_t pte, unsigned int nr,
672 				    unsigned long pgsize)
673 {
674 	unsigned long stride = pgsize >> PAGE_SHIFT;
675 
676 	switch (pgsize) {
677 	case PAGE_SIZE:
678 		page_table_check_ptes_set(mm, addr, ptep, pte, nr);
679 		break;
680 	case PMD_SIZE:
681 		page_table_check_pmds_set(mm, addr, (pmd_t *)ptep,
682 					  pte_pmd(pte), nr);
683 		break;
684 #ifndef __PAGETABLE_PMD_FOLDED
685 	case PUD_SIZE:
686 		page_table_check_puds_set(mm, addr, (pud_t *)ptep,
687 					  pte_pud(pte), nr);
688 		break;
689 #endif
690 	default:
691 		VM_WARN_ON(1);
692 	}
693 
694 	__sync_cache_and_tags(pte, nr * stride);
695 
696 	for (;;) {
697 		__check_safe_pte_update(mm, ptep, pte);
698 		__set_pte_nosync(ptep, pte);
699 		if (--nr == 0)
700 			break;
701 		ptep++;
702 		pte = pte_advance_pfn(pte, stride);
703 	}
704 
705 	__set_pte_complete(pte);
706 }
707 
708 static inline void __set_ptes(struct mm_struct *mm, unsigned long addr,
709 			      pte_t *ptep, pte_t pte, unsigned int nr)
710 {
711 	__set_ptes_anysz(mm, addr, ptep, pte, nr, PAGE_SIZE);
712 }
713 
714 static inline void __set_pmds(struct mm_struct *mm, unsigned long addr,
715 			      pmd_t *pmdp, pmd_t pmd, unsigned int nr)
716 {
717 	__set_ptes_anysz(mm, addr, (pte_t *)pmdp, pmd_pte(pmd), nr, PMD_SIZE);
718 }
719 #define set_pmd_at(mm, addr, pmdp, pmd) __set_pmds(mm, addr, pmdp, pmd, 1)
720 
721 static inline void __set_puds(struct mm_struct *mm, unsigned long addr,
722 			      pud_t *pudp, pud_t pud, unsigned int nr)
723 {
724 	__set_ptes_anysz(mm, addr, (pte_t *)pudp, pud_pte(pud), nr, PUD_SIZE);
725 }
726 #define set_pud_at(mm, addr, pudp, pud) __set_puds(mm, addr, pudp, pud, 1)
727 
728 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
729 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
730 
731 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
732 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
733 
734 #define __pgprot_modify(prot,mask,bits) \
735 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
736 
737 #define pgprot_nx(prot) \
738 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
739 
740 #define pgprot_decrypted(prot) \
741 	__pgprot_modify(prot, PROT_NS_SHARED, PROT_NS_SHARED)
742 #define pgprot_encrypted(prot) \
743 	__pgprot_modify(prot, PROT_NS_SHARED, 0)
744 
745 /*
746  * Mark the prot value as uncacheable and unbufferable.
747  */
748 #define pgprot_noncached(prot) \
749 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
750 #define pgprot_writecombine(prot) \
751 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
752 #define pgprot_device(prot) \
753 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
754 #define pgprot_tagged(prot) \
755 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
756 #define pgprot_mhp	pgprot_tagged
757 /*
758  * DMA allocations for non-coherent devices use what the Arm architecture calls
759  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
760  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
761  * is intended for MMIO and thus forbids speculation, preserves access size,
762  * requires strict alignment and can also force write responses to come from the
763  * endpoint.
764  */
765 #define pgprot_dmacoherent(prot) \
766 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
767 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
768 
769 #define __HAVE_PHYS_MEM_ACCESS_PROT
770 struct file;
771 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
772 				     unsigned long size, pgprot_t vma_prot);
773 
774 #define pmd_none(pmd)		(!pmd_val(pmd))
775 
776 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
777 				 PMD_TYPE_TABLE)
778 
779 #define pmd_leaf pmd_leaf
780 static inline bool pmd_leaf(pmd_t pmd)
781 {
782 	return pmd_present(pmd) && !pmd_table(pmd);
783 }
784 
785 #define pmd_bad(pmd)		(!pmd_table(pmd))
786 
787 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
788 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
789 
790 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
791 static inline int pmd_trans_huge(pmd_t pmd)
792 {
793 	/*
794 	 * If pmd is present-invalid, pmd_table() won't detect it
795 	 * as a table, so force the valid bit for the comparison.
796 	 */
797 	return pmd_present(pmd) && !pmd_table(__pmd(pmd_val(pmd) | PTE_VALID));
798 }
799 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
800 
801 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
802 static inline bool pud_table(pud_t pud) { return true; }
803 #else
804 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
805 				 PUD_TYPE_TABLE)
806 #endif
807 
808 extern pgd_t swapper_pg_dir[];
809 extern pgd_t idmap_pg_dir[];
810 extern pgd_t tramp_pg_dir[];
811 extern pgd_t reserved_pg_dir[];
812 
813 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
814 
815 static inline bool in_swapper_pgdir(void *addr)
816 {
817 	return ((unsigned long)addr & PAGE_MASK) ==
818 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
819 }
820 
821 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
822 {
823 #ifdef __PAGETABLE_PMD_FOLDED
824 	if (in_swapper_pgdir(pmdp)) {
825 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
826 		return;
827 	}
828 #endif /* __PAGETABLE_PMD_FOLDED */
829 
830 	WRITE_ONCE(*pmdp, pmd);
831 
832 	if (pmd_valid(pmd))
833 		queue_pte_barriers();
834 }
835 
836 static inline void pmd_clear(pmd_t *pmdp)
837 {
838 	set_pmd(pmdp, __pmd(0));
839 }
840 
841 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
842 {
843 	return __pmd_to_phys(pmd);
844 }
845 
846 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
847 {
848 	return (unsigned long)__va(pmd_page_paddr(pmd));
849 }
850 
851 /* Find an entry in the third-level page table. */
852 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
853 
854 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
855 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
856 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
857 
858 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
859 
860 /* use ONLY for statically allocated translation tables */
861 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
862 
863 #if CONFIG_PGTABLE_LEVELS > 2
864 
865 #define pmd_ERROR(e)	\
866 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
867 
868 #define pud_none(pud)		(!pud_val(pud))
869 #define pud_bad(pud)		((pud_val(pud) & PUD_TYPE_MASK) != \
870 				 PUD_TYPE_TABLE)
871 #define pud_present(pud)	pte_present(pud_pte(pud))
872 #ifndef __PAGETABLE_PMD_FOLDED
873 #define pud_leaf pud_leaf
874 static inline bool pud_leaf(pud_t pud)
875 {
876 	return pud_present(pud) && !pud_table(pud);
877 }
878 #else
879 #define pud_leaf(pud)		false
880 #endif
881 #define pud_valid(pud)		pte_valid(pud_pte(pud))
882 #define pud_user(pud)		pte_user(pud_pte(pud))
883 #define pud_user_exec(pud)	pte_user_exec(pud_pte(pud))
884 
885 static inline bool pgtable_l4_enabled(void);
886 
887 static inline void set_pud(pud_t *pudp, pud_t pud)
888 {
889 	if (!pgtable_l4_enabled() && in_swapper_pgdir(pudp)) {
890 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
891 		return;
892 	}
893 
894 	WRITE_ONCE(*pudp, pud);
895 
896 	if (pud_valid(pud))
897 		queue_pte_barriers();
898 }
899 
900 static inline void pud_clear(pud_t *pudp)
901 {
902 	set_pud(pudp, __pud(0));
903 }
904 
905 static inline phys_addr_t pud_page_paddr(pud_t pud)
906 {
907 	return __pud_to_phys(pud);
908 }
909 
910 static inline pmd_t *pud_pgtable(pud_t pud)
911 {
912 	return (pmd_t *)__va(pud_page_paddr(pud));
913 }
914 
915 /* Find an entry in the second-level page table. */
916 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
917 
918 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
919 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
920 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
921 
922 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
923 
924 /* use ONLY for statically allocated translation tables */
925 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
926 
927 #else
928 
929 #define pud_valid(pud)		false
930 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
931 #define pud_user_exec(pud)	pud_user(pud) /* Always 0 with folding */
932 
933 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
934 #define pmd_set_fixmap(addr)		NULL
935 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
936 #define pmd_clear_fixmap()
937 
938 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
939 
940 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
941 
942 #if CONFIG_PGTABLE_LEVELS > 3
943 
944 static __always_inline bool pgtable_l4_enabled(void)
945 {
946 	if (CONFIG_PGTABLE_LEVELS > 4 || !IS_ENABLED(CONFIG_ARM64_LPA2))
947 		return true;
948 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
949 		return vabits_actual == VA_BITS;
950 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
951 }
952 
953 static inline bool mm_pud_folded(const struct mm_struct *mm)
954 {
955 	return !pgtable_l4_enabled();
956 }
957 #define mm_pud_folded  mm_pud_folded
958 
959 #define pud_ERROR(e)	\
960 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
961 
962 #define p4d_none(p4d)		(pgtable_l4_enabled() && !p4d_val(p4d))
963 #define p4d_bad(p4d)		(pgtable_l4_enabled() && \
964 				((p4d_val(p4d) & P4D_TYPE_MASK) != \
965 				 P4D_TYPE_TABLE))
966 #define p4d_present(p4d)	(!p4d_none(p4d))
967 
968 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
969 {
970 	if (in_swapper_pgdir(p4dp)) {
971 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
972 		return;
973 	}
974 
975 	WRITE_ONCE(*p4dp, p4d);
976 	queue_pte_barriers();
977 }
978 
979 static inline void p4d_clear(p4d_t *p4dp)
980 {
981 	if (pgtable_l4_enabled())
982 		set_p4d(p4dp, __p4d(0));
983 }
984 
985 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
986 {
987 	return __p4d_to_phys(p4d);
988 }
989 
990 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
991 
992 static inline pud_t *p4d_to_folded_pud(p4d_t *p4dp, unsigned long addr)
993 {
994 	/* Ensure that 'p4dp' indexes a page table according to 'addr' */
995 	VM_BUG_ON(((addr >> P4D_SHIFT) ^ ((u64)p4dp >> 3)) % PTRS_PER_P4D);
996 
997 	return (pud_t *)PTR_ALIGN_DOWN(p4dp, PAGE_SIZE) + pud_index(addr);
998 }
999 
1000 static inline pud_t *p4d_pgtable(p4d_t p4d)
1001 {
1002 	return (pud_t *)__va(p4d_page_paddr(p4d));
1003 }
1004 
1005 static inline phys_addr_t pud_offset_phys(p4d_t *p4dp, unsigned long addr)
1006 {
1007 	VM_WARN_ON_ONCE(!pgtable_l4_enabled());
1008 
1009 	return p4d_page_paddr(READ_ONCE(*p4dp)) + pud_index(addr) * sizeof(pud_t);
1010 }
1011 
1012 static inline
1013 pud_t *pud_offset_lockless(p4d_t *p4dp, p4d_t p4d, unsigned long addr)
1014 {
1015 	if (!pgtable_l4_enabled())
1016 		return p4d_to_folded_pud(p4dp, addr);
1017 	return (pud_t *)__va(p4d_page_paddr(p4d)) + pud_index(addr);
1018 }
1019 #define pud_offset_lockless pud_offset_lockless
1020 
1021 static inline pud_t *pud_offset(p4d_t *p4dp, unsigned long addr)
1022 {
1023 	return pud_offset_lockless(p4dp, READ_ONCE(*p4dp), addr);
1024 }
1025 #define pud_offset	pud_offset
1026 
1027 static inline pud_t *pud_set_fixmap(unsigned long addr)
1028 {
1029 	if (!pgtable_l4_enabled())
1030 		return NULL;
1031 	return (pud_t *)set_fixmap_offset(FIX_PUD, addr);
1032 }
1033 
1034 static inline pud_t *pud_set_fixmap_offset(p4d_t *p4dp, unsigned long addr)
1035 {
1036 	if (!pgtable_l4_enabled())
1037 		return p4d_to_folded_pud(p4dp, addr);
1038 	return pud_set_fixmap(pud_offset_phys(p4dp, addr));
1039 }
1040 
1041 static inline void pud_clear_fixmap(void)
1042 {
1043 	if (pgtable_l4_enabled())
1044 		clear_fixmap(FIX_PUD);
1045 }
1046 
1047 /* use ONLY for statically allocated translation tables */
1048 static inline pud_t *pud_offset_kimg(p4d_t *p4dp, u64 addr)
1049 {
1050 	if (!pgtable_l4_enabled())
1051 		return p4d_to_folded_pud(p4dp, addr);
1052 	return (pud_t *)__phys_to_kimg(pud_offset_phys(p4dp, addr));
1053 }
1054 
1055 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
1056 
1057 #else
1058 
1059 static inline bool pgtable_l4_enabled(void) { return false; }
1060 
1061 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
1062 
1063 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
1064 #define pud_set_fixmap(addr)		NULL
1065 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
1066 #define pud_clear_fixmap()
1067 
1068 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
1069 
1070 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
1071 
1072 #if CONFIG_PGTABLE_LEVELS > 4
1073 
1074 static __always_inline bool pgtable_l5_enabled(void)
1075 {
1076 	if (!alternative_has_cap_likely(ARM64_ALWAYS_BOOT))
1077 		return vabits_actual == VA_BITS;
1078 	return alternative_has_cap_unlikely(ARM64_HAS_VA52);
1079 }
1080 
1081 static inline bool mm_p4d_folded(const struct mm_struct *mm)
1082 {
1083 	return !pgtable_l5_enabled();
1084 }
1085 #define mm_p4d_folded  mm_p4d_folded
1086 
1087 #define p4d_ERROR(e)	\
1088 	pr_err("%s:%d: bad p4d %016llx.\n", __FILE__, __LINE__, p4d_val(e))
1089 
1090 #define pgd_none(pgd)		(pgtable_l5_enabled() && !pgd_val(pgd))
1091 #define pgd_bad(pgd)		(pgtable_l5_enabled() && \
1092 				((pgd_val(pgd) & PGD_TYPE_MASK) != \
1093 				 PGD_TYPE_TABLE))
1094 #define pgd_present(pgd)	(!pgd_none(pgd))
1095 
1096 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
1097 {
1098 	if (in_swapper_pgdir(pgdp)) {
1099 		set_swapper_pgd(pgdp, __pgd(pgd_val(pgd)));
1100 		return;
1101 	}
1102 
1103 	WRITE_ONCE(*pgdp, pgd);
1104 	queue_pte_barriers();
1105 }
1106 
1107 static inline void pgd_clear(pgd_t *pgdp)
1108 {
1109 	if (pgtable_l5_enabled())
1110 		set_pgd(pgdp, __pgd(0));
1111 }
1112 
1113 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
1114 {
1115 	return __pgd_to_phys(pgd);
1116 }
1117 
1118 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1119 
1120 static inline p4d_t *pgd_to_folded_p4d(pgd_t *pgdp, unsigned long addr)
1121 {
1122 	/* Ensure that 'pgdp' indexes a page table according to 'addr' */
1123 	VM_BUG_ON(((addr >> PGDIR_SHIFT) ^ ((u64)pgdp >> 3)) % PTRS_PER_PGD);
1124 
1125 	return (p4d_t *)PTR_ALIGN_DOWN(pgdp, PAGE_SIZE) + p4d_index(addr);
1126 }
1127 
1128 static inline phys_addr_t p4d_offset_phys(pgd_t *pgdp, unsigned long addr)
1129 {
1130 	VM_WARN_ON_ONCE(!pgtable_l5_enabled());
1131 
1132 	return pgd_page_paddr(READ_ONCE(*pgdp)) + p4d_index(addr) * sizeof(p4d_t);
1133 }
1134 
1135 static inline
1136 p4d_t *p4d_offset_lockless(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1137 {
1138 	if (!pgtable_l5_enabled())
1139 		return pgd_to_folded_p4d(pgdp, addr);
1140 	return (p4d_t *)__va(pgd_page_paddr(pgd)) + p4d_index(addr);
1141 }
1142 #define p4d_offset_lockless p4d_offset_lockless
1143 
1144 static inline p4d_t *p4d_offset(pgd_t *pgdp, unsigned long addr)
1145 {
1146 	return p4d_offset_lockless(pgdp, READ_ONCE(*pgdp), addr);
1147 }
1148 
1149 static inline p4d_t *p4d_set_fixmap(unsigned long addr)
1150 {
1151 	if (!pgtable_l5_enabled())
1152 		return NULL;
1153 	return (p4d_t *)set_fixmap_offset(FIX_P4D, addr);
1154 }
1155 
1156 static inline p4d_t *p4d_set_fixmap_offset(pgd_t *pgdp, unsigned long addr)
1157 {
1158 	if (!pgtable_l5_enabled())
1159 		return pgd_to_folded_p4d(pgdp, addr);
1160 	return p4d_set_fixmap(p4d_offset_phys(pgdp, addr));
1161 }
1162 
1163 static inline void p4d_clear_fixmap(void)
1164 {
1165 	if (pgtable_l5_enabled())
1166 		clear_fixmap(FIX_P4D);
1167 }
1168 
1169 /* use ONLY for statically allocated translation tables */
1170 static inline p4d_t *p4d_offset_kimg(pgd_t *pgdp, u64 addr)
1171 {
1172 	if (!pgtable_l5_enabled())
1173 		return pgd_to_folded_p4d(pgdp, addr);
1174 	return (p4d_t *)__phys_to_kimg(p4d_offset_phys(pgdp, addr));
1175 }
1176 
1177 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(__pgd_to_phys(pgd)))
1178 
1179 #else
1180 
1181 static inline bool pgtable_l5_enabled(void) { return false; }
1182 
1183 #define p4d_index(addr)		(((addr) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
1184 
1185 /* Match p4d_offset folding in <asm/generic/pgtable-nop4d.h> */
1186 #define p4d_set_fixmap(addr)		NULL
1187 #define p4d_set_fixmap_offset(p4dp, addr)	((p4d_t *)p4dp)
1188 #define p4d_clear_fixmap()
1189 
1190 #define p4d_offset_kimg(dir,addr)	((p4d_t *)dir)
1191 
1192 static inline
1193 p4d_t *p4d_offset_lockless_folded(pgd_t *pgdp, pgd_t pgd, unsigned long addr)
1194 {
1195 	/*
1196 	 * With runtime folding of the pud, pud_offset_lockless() passes
1197 	 * the 'pgd_t *' we return here to p4d_to_folded_pud(), which
1198 	 * will offset the pointer assuming that it points into
1199 	 * a page-table page. However, the fast GUP path passes us a
1200 	 * pgd_t allocated on the stack and so we must use the original
1201 	 * pointer in 'pgdp' to construct the p4d pointer instead of
1202 	 * using the generic p4d_offset_lockless() implementation.
1203 	 *
1204 	 * Note: reusing the original pointer means that we may
1205 	 * dereference the same (live) page-table entry multiple times.
1206 	 * This is safe because it is still only loaded once in the
1207 	 * context of each level and the CPU guarantees same-address
1208 	 * read-after-read ordering.
1209 	 */
1210 	return p4d_offset(pgdp, addr);
1211 }
1212 #define p4d_offset_lockless p4d_offset_lockless_folded
1213 
1214 #endif  /* CONFIG_PGTABLE_LEVELS > 4 */
1215 
1216 #define pgd_ERROR(e)	\
1217 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
1218 
1219 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
1220 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
1221 
1222 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
1223 {
1224 	/*
1225 	 * Normal and Normal-Tagged are two different memory types and indices
1226 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
1227 	 */
1228 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
1229 			      PTE_PRESENT_INVALID | PTE_VALID | PTE_WRITE |
1230 			      PTE_GP | PTE_ATTRINDX_MASK | PTE_PO_IDX_MASK;
1231 
1232 	/* preserve the hardware dirty information */
1233 	if (pte_hw_dirty(pte))
1234 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
1235 
1236 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
1237 	/*
1238 	 * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware
1239 	 * dirtiness again.
1240 	 */
1241 	if (pte_sw_dirty(pte))
1242 		pte = pte_mkdirty(pte);
1243 	return pte;
1244 }
1245 
1246 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1247 {
1248 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
1249 }
1250 
1251 extern int __ptep_set_access_flags_anysz(struct vm_area_struct *vma,
1252 					 unsigned long address, pte_t *ptep,
1253 					 pte_t entry, int dirty,
1254 					 unsigned long pgsize);
1255 
1256 static inline int __ptep_set_access_flags(struct vm_area_struct *vma,
1257 					  unsigned long address, pte_t *ptep,
1258 					  pte_t entry, int dirty)
1259 {
1260 	return __ptep_set_access_flags_anysz(vma, address, ptep, entry, dirty,
1261 					     PAGE_SIZE);
1262 }
1263 
1264 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1265 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1266 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1267 					unsigned long address, pmd_t *pmdp,
1268 					pmd_t entry, int dirty)
1269 {
1270 	return __ptep_set_access_flags_anysz(vma, address, (pte_t *)pmdp,
1271 					     pmd_pte(entry), dirty, PMD_SIZE);
1272 }
1273 #endif
1274 
1275 #ifdef CONFIG_PAGE_TABLE_CHECK
1276 static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
1277 {
1278 	return pte_valid(pte) && (pte_user(pte) || pte_user_exec(pte));
1279 }
1280 
1281 static inline bool pmd_user_accessible_page(struct mm_struct *mm, unsigned long addr, pmd_t pmd)
1282 {
1283 	return pmd_valid(pmd) && !pmd_table(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
1284 }
1285 
1286 static inline bool pud_user_accessible_page(struct mm_struct *mm, unsigned long addr, pud_t pud)
1287 {
1288 	return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
1289 }
1290 #endif
1291 
1292 /*
1293  * Atomic pte/pmd modifications.
1294  */
1295 
1296 static inline void __pte_clear(struct mm_struct *mm,
1297 			       unsigned long addr, pte_t *ptep)
1298 {
1299 	__set_pte(ptep, __pte(0));
1300 }
1301 
1302 static inline bool __ptep_test_and_clear_young(struct vm_area_struct *vma,
1303 		unsigned long address, pte_t *ptep)
1304 {
1305 	pte_t old_pte, pte;
1306 
1307 	pte = __ptep_get(ptep);
1308 	do {
1309 		old_pte = pte;
1310 		pte = pte_mkold(pte);
1311 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1312 					       pte_val(old_pte), pte_val(pte));
1313 	} while (pte_val(pte) != pte_val(old_pte));
1314 
1315 	return pte_young(pte);
1316 }
1317 
1318 static inline bool __ptep_clear_flush_young(struct vm_area_struct *vma,
1319 		unsigned long address, pte_t *ptep)
1320 {
1321 	bool young = __ptep_test_and_clear_young(vma, address, ptep);
1322 
1323 	if (young) {
1324 		/*
1325 		 * We can elide the trailing DSB here since the worst that can
1326 		 * happen is that a CPU continues to use the young entry in its
1327 		 * TLB and we mistakenly reclaim the associated page. The
1328 		 * window for such an event is bounded by the next
1329 		 * context-switch, which provides a DSB to complete the TLB
1330 		 * invalidation.
1331 		 */
1332 		__flush_tlb_page(vma, address, TLBF_NOSYNC);
1333 	}
1334 
1335 	return young;
1336 }
1337 
1338 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
1339 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1340 static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
1341 		unsigned long address, pmd_t *pmdp)
1342 {
1343 	/* Operation applies to PMD table entry only if FEAT_HAFT is enabled */
1344 	VM_WARN_ON(pmd_table(READ_ONCE(*pmdp)) && !system_supports_haft());
1345 	return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1346 }
1347 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
1348 
1349 static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
1350 					       unsigned long address,
1351 					       pte_t *ptep,
1352 					       unsigned long pgsize)
1353 {
1354 	pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0));
1355 
1356 	switch (pgsize) {
1357 	case PAGE_SIZE:
1358 		page_table_check_pte_clear(mm, address, pte);
1359 		break;
1360 	case PMD_SIZE:
1361 		page_table_check_pmd_clear(mm, address, pte_pmd(pte));
1362 		break;
1363 #ifndef __PAGETABLE_PMD_FOLDED
1364 	case PUD_SIZE:
1365 		page_table_check_pud_clear(mm, address, pte_pud(pte));
1366 		break;
1367 #endif
1368 	default:
1369 		VM_WARN_ON(1);
1370 	}
1371 
1372 	return pte;
1373 }
1374 
1375 static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
1376 				       unsigned long address, pte_t *ptep)
1377 {
1378 	return __ptep_get_and_clear_anysz(mm, address, ptep, PAGE_SIZE);
1379 }
1380 
1381 static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1382 				pte_t *ptep, unsigned int nr, int full)
1383 {
1384 	for (;;) {
1385 		__ptep_get_and_clear(mm, addr, ptep);
1386 		if (--nr == 0)
1387 			break;
1388 		ptep++;
1389 		addr += PAGE_SIZE;
1390 	}
1391 }
1392 
1393 static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm,
1394 				unsigned long addr, pte_t *ptep,
1395 				unsigned int nr, int full)
1396 {
1397 	pte_t pte, tmp_pte;
1398 
1399 	pte = __ptep_get_and_clear(mm, addr, ptep);
1400 	while (--nr) {
1401 		ptep++;
1402 		addr += PAGE_SIZE;
1403 		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
1404 		if (pte_dirty(tmp_pte))
1405 			pte = pte_mkdirty(pte);
1406 		if (pte_young(tmp_pte))
1407 			pte = pte_mkyoung(pte);
1408 	}
1409 	return pte;
1410 }
1411 
1412 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1413 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1414 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1415 					    unsigned long address, pmd_t *pmdp)
1416 {
1417 	return pte_pmd(__ptep_get_and_clear_anysz(mm, address, (pte_t *)pmdp, PMD_SIZE));
1418 }
1419 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1420 
1421 static inline void ___ptep_set_wrprotect(struct mm_struct *mm,
1422 					unsigned long address, pte_t *ptep,
1423 					pte_t pte)
1424 {
1425 	pte_t old_pte;
1426 
1427 	do {
1428 		old_pte = pte;
1429 		pte = pte_wrprotect(pte);
1430 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1431 					       pte_val(old_pte), pte_val(pte));
1432 	} while (pte_val(pte) != pte_val(old_pte));
1433 }
1434 
1435 /*
1436  * __ptep_set_wrprotect - mark read-only while transferring potential hardware
1437  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
1438  */
1439 static inline void __ptep_set_wrprotect(struct mm_struct *mm,
1440 					unsigned long address, pte_t *ptep)
1441 {
1442 	___ptep_set_wrprotect(mm, address, ptep, __ptep_get(ptep));
1443 }
1444 
1445 static inline void __wrprotect_ptes(struct mm_struct *mm, unsigned long address,
1446 				pte_t *ptep, unsigned int nr)
1447 {
1448 	unsigned int i;
1449 
1450 	for (i = 0; i < nr; i++, address += PAGE_SIZE, ptep++)
1451 		__ptep_set_wrprotect(mm, address, ptep);
1452 }
1453 
1454 static inline void __clear_young_dirty_pte(struct vm_area_struct *vma,
1455 					   unsigned long addr, pte_t *ptep,
1456 					   pte_t pte, cydp_t flags)
1457 {
1458 	pte_t old_pte;
1459 
1460 	do {
1461 		old_pte = pte;
1462 
1463 		if (flags & CYDP_CLEAR_YOUNG)
1464 			pte = pte_mkold(pte);
1465 		if (flags & CYDP_CLEAR_DIRTY)
1466 			pte = pte_mkclean(pte);
1467 
1468 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
1469 					       pte_val(old_pte), pte_val(pte));
1470 	} while (pte_val(pte) != pte_val(old_pte));
1471 }
1472 
1473 static inline void __clear_young_dirty_ptes(struct vm_area_struct *vma,
1474 					    unsigned long addr, pte_t *ptep,
1475 					    unsigned int nr, cydp_t flags)
1476 {
1477 	pte_t pte;
1478 
1479 	for (;;) {
1480 		pte = __ptep_get(ptep);
1481 
1482 		if (flags == (CYDP_CLEAR_YOUNG | CYDP_CLEAR_DIRTY))
1483 			__set_pte(ptep, pte_mkclean(pte_mkold(pte)));
1484 		else
1485 			__clear_young_dirty_pte(vma, addr, ptep, pte, flags);
1486 
1487 		if (--nr == 0)
1488 			break;
1489 		ptep++;
1490 		addr += PAGE_SIZE;
1491 	}
1492 }
1493 
1494 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1495 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1496 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1497 				      unsigned long address, pmd_t *pmdp)
1498 {
1499 	__ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1500 }
1501 
1502 #define pmdp_establish pmdp_establish
1503 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1504 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
1505 {
1506 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
1507 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
1508 }
1509 #endif
1510 
1511 /*
1512  * Encode and decode a swap entry:
1513  *	bits 0-1:	present (must be zero)
1514  *	bits 2:		remember PG_anon_exclusive
1515  *	bit  3:		remember uffd state
1516  *	bits 6-10:	swap type
1517  *	bit  11:	PTE_PRESENT_INVALID (must be zero)
1518  *	bits 12-61:	swap offset
1519  */
1520 #define __SWP_TYPE_SHIFT	6
1521 #define __SWP_TYPE_BITS		5
1522 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
1523 #define __SWP_OFFSET_SHIFT	12
1524 #define __SWP_OFFSET_BITS	50
1525 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
1526 
1527 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1528 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
1529 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
1530 
1531 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1532 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
1533 
1534 #ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
1535 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
1536 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
1537 #endif /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
1538 
1539 /*
1540  * Ensure that there are not more swap files than can be encoded in the kernel
1541  * PTEs.
1542  */
1543 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1544 
1545 #ifdef CONFIG_ARM64_MTE
1546 
1547 #define __HAVE_ARCH_PREPARE_TO_SWAP
1548 extern int arch_prepare_to_swap(struct folio *folio);
1549 
1550 #define __HAVE_ARCH_SWAP_INVALIDATE
1551 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
1552 {
1553 	if (system_supports_mte())
1554 		mte_invalidate_tags(type, offset);
1555 }
1556 
1557 static inline void arch_swap_invalidate_area(int type)
1558 {
1559 	if (system_supports_mte())
1560 		mte_invalidate_tags_area(type);
1561 }
1562 
1563 #define __HAVE_ARCH_SWAP_RESTORE
1564 extern void arch_swap_restore(swp_entry_t entry, struct folio *folio);
1565 
1566 #endif /* CONFIG_ARM64_MTE */
1567 
1568 /*
1569  * On AArch64, the cache coherency is handled via the __set_ptes() function.
1570  */
1571 static inline void update_mmu_cache_range(struct vm_fault *vmf,
1572 		struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
1573 		unsigned int nr)
1574 {
1575 	/*
1576 	 * We don't do anything here, so there's a very small chance of
1577 	 * us retaking a user fault which we just fixed up. The alternative
1578 	 * is doing a dsb(ishst), but that penalises the fastpath.
1579 	 */
1580 }
1581 
1582 #define update_mmu_cache(vma, addr, ptep) \
1583 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
1584 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
1585 
1586 #ifdef CONFIG_ARM64_PA_BITS_52
1587 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
1588 #else
1589 #define phys_to_ttbr(addr)	(addr)
1590 #endif
1591 
1592 /*
1593  * On arm64 without hardware Access Flag, copying from user will fail because
1594  * the pte is old and cannot be marked young. So we always end up with zeroed
1595  * page after fork() + CoW for pfn mappings. We don't always have a
1596  * hardware-managed access flag on arm64.
1597  */
1598 #define arch_has_hw_pte_young		cpu_has_hw_af
1599 
1600 #ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
1601 #define arch_has_hw_nonleaf_pmd_young	system_supports_haft
1602 #endif
1603 
1604 /*
1605  * Experimentally, it's cheap to set the access flag in hardware and we
1606  * benefit from prefaulting mappings as 'old' to start with.
1607  */
1608 #define arch_wants_old_prefaulted_pte	cpu_has_hw_af
1609 
1610 /*
1611  * Request exec memory is read into pagecache in at least 64K folios. This size
1612  * can be contpte-mapped when 4K base pages are in use (16 pages into 1 iTLB
1613  * entry), and HPA can coalesce it (4 pages into 1 TLB entry) when 16K base
1614  * pages are in use.
1615  */
1616 #define exec_folio_order() ilog2(SZ_64K >> PAGE_SHIFT)
1617 
1618 static inline bool pud_sect_supported(void)
1619 {
1620 	return PAGE_SIZE == SZ_4K;
1621 }
1622 
1623 
1624 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1625 #define ptep_modify_prot_start ptep_modify_prot_start
1626 extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
1627 				    unsigned long addr, pte_t *ptep);
1628 
1629 #define ptep_modify_prot_commit ptep_modify_prot_commit
1630 extern void ptep_modify_prot_commit(struct vm_area_struct *vma,
1631 				    unsigned long addr, pte_t *ptep,
1632 				    pte_t old_pte, pte_t new_pte);
1633 
1634 #define modify_prot_start_ptes modify_prot_start_ptes
1635 extern pte_t modify_prot_start_ptes(struct vm_area_struct *vma,
1636 				    unsigned long addr, pte_t *ptep,
1637 				    unsigned int nr);
1638 
1639 #define modify_prot_commit_ptes modify_prot_commit_ptes
1640 extern void modify_prot_commit_ptes(struct vm_area_struct *vma, unsigned long addr,
1641 				    pte_t *ptep, pte_t old_pte, pte_t pte,
1642 				    unsigned int nr);
1643 
1644 #ifdef CONFIG_ARM64_CONTPTE
1645 
1646 /*
1647  * The contpte APIs are used to transparently manage the contiguous bit in ptes
1648  * where it is possible and makes sense to do so. The PTE_CONT bit is considered
1649  * a private implementation detail of the public ptep API (see below).
1650  */
1651 extern void __contpte_try_fold(struct mm_struct *mm, unsigned long addr,
1652 				pte_t *ptep, pte_t pte);
1653 extern void __contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
1654 				pte_t *ptep, pte_t pte);
1655 extern pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte);
1656 extern pte_t contpte_ptep_get_lockless(pte_t *orig_ptep);
1657 extern void contpte_set_ptes(struct mm_struct *mm, unsigned long addr,
1658 				pte_t *ptep, pte_t pte, unsigned int nr);
1659 extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1660 				pte_t *ptep, unsigned int nr, int full);
1661 extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,
1662 				unsigned long addr, pte_t *ptep,
1663 				unsigned int nr, int full);
1664 bool contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,
1665 				unsigned long addr, pte_t *ptep, unsigned int nr);
1666 bool contpte_clear_flush_young_ptes(struct vm_area_struct *vma,
1667 				unsigned long addr, pte_t *ptep, unsigned int nr);
1668 extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
1669 				pte_t *ptep, unsigned int nr);
1670 extern int contpte_ptep_set_access_flags(struct vm_area_struct *vma,
1671 				unsigned long addr, pte_t *ptep,
1672 				pte_t entry, int dirty);
1673 extern void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,
1674 				unsigned long addr, pte_t *ptep,
1675 				unsigned int nr, cydp_t flags);
1676 
1677 static __always_inline void contpte_try_fold(struct mm_struct *mm,
1678 				unsigned long addr, pte_t *ptep, pte_t pte)
1679 {
1680 	/*
1681 	 * Only bother trying if both the virtual and physical addresses are
1682 	 * aligned and correspond to the last entry in a contig range. The core
1683 	 * code mostly modifies ranges from low to high, so this is the likely
1684 	 * the last modification in the contig range, so a good time to fold.
1685 	 * We can't fold special mappings, because there is no associated folio.
1686 	 */
1687 
1688 	const unsigned long contmask = CONT_PTES - 1;
1689 	bool valign = ((addr >> PAGE_SHIFT) & contmask) == contmask;
1690 
1691 	if (unlikely(valign)) {
1692 		bool palign = (pte_pfn(pte) & contmask) == contmask;
1693 
1694 		if (unlikely(palign &&
1695 		    pte_valid(pte) && !pte_cont(pte) && !pte_special(pte)))
1696 			__contpte_try_fold(mm, addr, ptep, pte);
1697 	}
1698 }
1699 
1700 static __always_inline void contpte_try_unfold(struct mm_struct *mm,
1701 				unsigned long addr, pte_t *ptep, pte_t pte)
1702 {
1703 	if (unlikely(pte_valid_cont(pte)))
1704 		__contpte_try_unfold(mm, addr, ptep, pte);
1705 }
1706 
1707 #define pte_batch_hint pte_batch_hint
1708 static inline unsigned int pte_batch_hint(pte_t *ptep, pte_t pte)
1709 {
1710 	if (!pte_valid_cont(pte))
1711 		return 1;
1712 
1713 	return CONT_PTES - (((unsigned long)ptep >> 3) & (CONT_PTES - 1));
1714 }
1715 
1716 /*
1717  * The below functions constitute the public API that arm64 presents to the
1718  * core-mm to manipulate PTE entries within their page tables (or at least this
1719  * is the subset of the API that arm64 needs to implement). These public
1720  * versions will automatically and transparently apply the contiguous bit where
1721  * it makes sense to do so. Therefore any users that are contig-aware (e.g.
1722  * hugetlb, kernel mapper) should NOT use these APIs, but instead use the
1723  * private versions, which are prefixed with double underscore. All of these
1724  * APIs except for ptep_get_lockless() are expected to be called with the PTL
1725  * held. Although the contiguous bit is considered private to the
1726  * implementation, it is deliberately allowed to leak through the getters (e.g.
1727  * ptep_get()), back to core code. This is required so that pte_leaf_size() can
1728  * provide an accurate size for perf_get_pgtable_size(). But this leakage means
1729  * its possible a pte will be passed to a setter with the contiguous bit set, so
1730  * we explicitly clear the contiguous bit in those cases to prevent accidentally
1731  * setting it in the pgtable.
1732  */
1733 
1734 #define ptep_get ptep_get
1735 static inline pte_t ptep_get(pte_t *ptep)
1736 {
1737 	pte_t pte = __ptep_get(ptep);
1738 
1739 	if (likely(!pte_valid_cont(pte)))
1740 		return pte;
1741 
1742 	return contpte_ptep_get(ptep, pte);
1743 }
1744 
1745 #define ptep_get_lockless ptep_get_lockless
1746 static inline pte_t ptep_get_lockless(pte_t *ptep)
1747 {
1748 	pte_t pte = __ptep_get(ptep);
1749 
1750 	if (likely(!pte_valid_cont(pte)))
1751 		return pte;
1752 
1753 	return contpte_ptep_get_lockless(ptep);
1754 }
1755 
1756 static inline void set_pte(pte_t *ptep, pte_t pte)
1757 {
1758 	/*
1759 	 * We don't have the mm or vaddr so cannot unfold contig entries (since
1760 	 * it requires tlb maintenance). set_pte() is not used in core code, so
1761 	 * this should never even be called. Regardless do our best to service
1762 	 * any call and emit a warning if there is any attempt to set a pte on
1763 	 * top of an existing contig range.
1764 	 */
1765 	pte_t orig_pte = __ptep_get(ptep);
1766 
1767 	WARN_ON_ONCE(pte_valid_cont(orig_pte));
1768 	__set_pte(ptep, pte_mknoncont(pte));
1769 }
1770 
1771 #define set_ptes set_ptes
1772 static __always_inline void set_ptes(struct mm_struct *mm, unsigned long addr,
1773 				pte_t *ptep, pte_t pte, unsigned int nr)
1774 {
1775 	pte = pte_mknoncont(pte);
1776 
1777 	if (likely(nr == 1)) {
1778 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1779 		__set_ptes(mm, addr, ptep, pte, 1);
1780 		contpte_try_fold(mm, addr, ptep, pte);
1781 	} else {
1782 		contpte_set_ptes(mm, addr, ptep, pte, nr);
1783 	}
1784 }
1785 
1786 static inline void pte_clear(struct mm_struct *mm,
1787 				unsigned long addr, pte_t *ptep)
1788 {
1789 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1790 	__pte_clear(mm, addr, ptep);
1791 }
1792 
1793 #define clear_full_ptes clear_full_ptes
1794 static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr,
1795 				pte_t *ptep, unsigned int nr, int full)
1796 {
1797 	if (likely(nr == 1)) {
1798 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1799 		__clear_full_ptes(mm, addr, ptep, nr, full);
1800 	} else {
1801 		contpte_clear_full_ptes(mm, addr, ptep, nr, full);
1802 	}
1803 }
1804 
1805 #define get_and_clear_full_ptes get_and_clear_full_ptes
1806 static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm,
1807 				unsigned long addr, pte_t *ptep,
1808 				unsigned int nr, int full)
1809 {
1810 	pte_t pte;
1811 
1812 	if (likely(nr == 1)) {
1813 		contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1814 		pte = __get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1815 	} else {
1816 		pte = contpte_get_and_clear_full_ptes(mm, addr, ptep, nr, full);
1817 	}
1818 
1819 	return pte;
1820 }
1821 
1822 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1823 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1824 				unsigned long addr, pte_t *ptep)
1825 {
1826 	contpte_try_unfold(mm, addr, ptep, __ptep_get(ptep));
1827 	return __ptep_get_and_clear(mm, addr, ptep);
1828 }
1829 
1830 static inline bool ptep_try_set(pte_t *ptep, pte_t new_pte)
1831 {
1832 	pteval_t old = 0;
1833 
1834 	if (!try_cmpxchg(&pte_val(*ptep), &old, pte_val(new_pte)))
1835 		return false;
1836 
1837 	/*
1838 	 * The store must be complete by the time this returns, but the caller
1839 	 * may be in lazy MMU mode, where __set_pte_complete() would defer the
1840 	 * barriers. Issue them directly.
1841 	 */
1842 	emit_pte_barriers();
1843 	return true;
1844 }
1845 #define ptep_try_set ptep_try_set
1846 
1847 /*
1848  * arm64 mandates break-before-make: a cleared kernel PTE must have its TLB
1849  * invalidated before a different page is installed in its place. The broadcast
1850  * TLBI is an instruction, not an IPI, so this is safe with interrupts disabled.
1851  */
1852 static inline void flush_tlb_before_set(unsigned long addr)
1853 {
1854 	flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
1855 }
1856 #define flush_tlb_before_set flush_tlb_before_set
1857 
1858 #define test_and_clear_young_ptes test_and_clear_young_ptes
1859 static inline bool test_and_clear_young_ptes(struct vm_area_struct *vma,
1860 		unsigned long addr, pte_t *ptep, unsigned int nr)
1861 {
1862 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
1863 		return __ptep_test_and_clear_young(vma, addr, ptep);
1864 
1865 	return contpte_test_and_clear_young_ptes(vma, addr, ptep, nr);
1866 }
1867 
1868 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1869 static inline bool ptep_test_and_clear_young(struct vm_area_struct *vma,
1870 		unsigned long addr, pte_t *ptep)
1871 {
1872 	return test_and_clear_young_ptes(vma, addr, ptep, 1);
1873 }
1874 
1875 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1876 static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
1877 		unsigned long addr, pte_t *ptep)
1878 {
1879 	pte_t orig_pte = __ptep_get(ptep);
1880 
1881 	if (likely(!pte_valid_cont(orig_pte)))
1882 		return __ptep_clear_flush_young(vma, addr, ptep);
1883 
1884 	return contpte_clear_flush_young_ptes(vma, addr, ptep, 1);
1885 }
1886 
1887 #define clear_flush_young_ptes clear_flush_young_ptes
1888 static inline bool clear_flush_young_ptes(struct vm_area_struct *vma,
1889 		unsigned long addr, pte_t *ptep, unsigned int nr)
1890 {
1891 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
1892 		return __ptep_clear_flush_young(vma, addr, ptep);
1893 
1894 	return contpte_clear_flush_young_ptes(vma, addr, ptep, nr);
1895 }
1896 
1897 #define wrprotect_ptes wrprotect_ptes
1898 static __always_inline void wrprotect_ptes(struct mm_struct *mm,
1899 				unsigned long addr, pte_t *ptep, unsigned int nr)
1900 {
1901 	if (likely(nr == 1)) {
1902 		/*
1903 		 * Optimization: wrprotect_ptes() can only be called for present
1904 		 * ptes so we only need to check contig bit as condition for
1905 		 * unfold, and we can remove the contig bit from the pte we read
1906 		 * to avoid re-reading. This speeds up fork() which is sensitive
1907 		 * for order-0 folios. Equivalent to contpte_try_unfold().
1908 		 */
1909 		pte_t orig_pte = __ptep_get(ptep);
1910 
1911 		if (unlikely(pte_cont(orig_pte))) {
1912 			__contpte_try_unfold(mm, addr, ptep, orig_pte);
1913 			orig_pte = pte_mknoncont(orig_pte);
1914 		}
1915 		___ptep_set_wrprotect(mm, addr, ptep, orig_pte);
1916 	} else {
1917 		contpte_wrprotect_ptes(mm, addr, ptep, nr);
1918 	}
1919 }
1920 
1921 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1922 static inline void ptep_set_wrprotect(struct mm_struct *mm,
1923 				unsigned long addr, pte_t *ptep)
1924 {
1925 	wrprotect_ptes(mm, addr, ptep, 1);
1926 }
1927 
1928 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1929 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1930 				unsigned long addr, pte_t *ptep,
1931 				pte_t entry, int dirty)
1932 {
1933 	pte_t orig_pte = __ptep_get(ptep);
1934 
1935 	entry = pte_mknoncont(entry);
1936 
1937 	if (likely(!pte_valid_cont(orig_pte)))
1938 		return __ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1939 
1940 	return contpte_ptep_set_access_flags(vma, addr, ptep, entry, dirty);
1941 }
1942 
1943 #define clear_young_dirty_ptes clear_young_dirty_ptes
1944 static inline void clear_young_dirty_ptes(struct vm_area_struct *vma,
1945 					  unsigned long addr, pte_t *ptep,
1946 					  unsigned int nr, cydp_t flags)
1947 {
1948 	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))
1949 		__clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1950 	else
1951 		contpte_clear_young_dirty_ptes(vma, addr, ptep, nr, flags);
1952 }
1953 
1954 #else /* CONFIG_ARM64_CONTPTE */
1955 
1956 #define ptep_get				__ptep_get
1957 #define set_pte					__set_pte
1958 #define set_ptes				__set_ptes
1959 #define pte_clear				__pte_clear
1960 #define clear_full_ptes				__clear_full_ptes
1961 #define get_and_clear_full_ptes			__get_and_clear_full_ptes
1962 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1963 #define ptep_get_and_clear			__ptep_get_and_clear
1964 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1965 #define ptep_test_and_clear_young		__ptep_test_and_clear_young
1966 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1967 #define ptep_clear_flush_young			__ptep_clear_flush_young
1968 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1969 #define ptep_set_wrprotect			__ptep_set_wrprotect
1970 #define wrprotect_ptes				__wrprotect_ptes
1971 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1972 #define ptep_set_access_flags			__ptep_set_access_flags
1973 #define clear_young_dirty_ptes			__clear_young_dirty_ptes
1974 
1975 #endif /* CONFIG_ARM64_CONTPTE */
1976 
1977 #endif /* !__ASSEMBLER__ */
1978 
1979 #endif /* __ASM_PGTABLE_H */
1980