xref: /openbmc/linux/arch/arm64/include/asm/pgtable.h (revision cef69974)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_PGTABLE_H
6 #define __ASM_PGTABLE_H
7 
8 #include <asm/bug.h>
9 #include <asm/proc-fns.h>
10 
11 #include <asm/memory.h>
12 #include <asm/mte.h>
13 #include <asm/pgtable-hwdef.h>
14 #include <asm/pgtable-prot.h>
15 #include <asm/tlbflush.h>
16 
17 /*
18  * VMALLOC range.
19  *
20  * VMALLOC_START: beginning of the kernel vmalloc space
21  * VMALLOC_END: extends to the available space below vmemmap, PCI I/O space
22  *	and fixed mappings
23  */
24 #define VMALLOC_START		(MODULES_END)
25 #define VMALLOC_END		(VMEMMAP_START - SZ_256M)
26 
27 #define vmemmap			((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
28 
29 #ifndef __ASSEMBLY__
30 
31 #include <asm/cmpxchg.h>
32 #include <asm/fixmap.h>
33 #include <linux/mmdebug.h>
34 #include <linux/mm_types.h>
35 #include <linux/sched.h>
36 
37 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
38 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
39 
40 /* Set stride and tlb_level in flush_*_tlb_range */
41 #define flush_pmd_tlb_range(vma, addr, end)	\
42 	__flush_tlb_range(vma, addr, end, PMD_SIZE, false, 2)
43 #define flush_pud_tlb_range(vma, addr, end)	\
44 	__flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1)
45 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
46 
47 /*
48  * Outside of a few very special situations (e.g. hibernation), we always
49  * use broadcast TLB invalidation instructions, therefore a spurious page
50  * fault on one CPU which has been handled concurrently by another CPU
51  * does not need to perform additional invalidation.
52  */
53 #define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
54 
55 /*
56  * ZERO_PAGE is a global shared page that is always zero: used
57  * for zero-mapped memory areas etc..
58  */
59 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
60 #define ZERO_PAGE(vaddr)	phys_to_page(__pa_symbol(empty_zero_page))
61 
62 #define pte_ERROR(e)	\
63 	pr_err("%s:%d: bad pte %016llx.\n", __FILE__, __LINE__, pte_val(e))
64 
65 /*
66  * Macros to convert between a physical address and its placement in a
67  * page table entry, taking care of 52-bit addresses.
68  */
69 #ifdef CONFIG_ARM64_PA_BITS_52
70 static inline phys_addr_t __pte_to_phys(pte_t pte)
71 {
72 	return (pte_val(pte) & PTE_ADDR_LOW) |
73 		((pte_val(pte) & PTE_ADDR_HIGH) << 36);
74 }
75 static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
76 {
77 	return (phys | (phys >> 36)) & PTE_ADDR_MASK;
78 }
79 #else
80 #define __pte_to_phys(pte)	(pte_val(pte) & PTE_ADDR_MASK)
81 #define __phys_to_pte_val(phys)	(phys)
82 #endif
83 
84 #define pte_pfn(pte)		(__pte_to_phys(pte) >> PAGE_SHIFT)
85 #define pfn_pte(pfn,prot)	\
86 	__pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
87 
88 #define pte_none(pte)		(!pte_val(pte))
89 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
90 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
91 
92 /*
93  * The following only work if pte_present(). Undefined behaviour otherwise.
94  */
95 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
96 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
97 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
98 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
99 #define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
100 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
101 #define pte_devmap(pte)		(!!(pte_val(pte) & PTE_DEVMAP))
102 #define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \
103 				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
104 
105 #define pte_cont_addr_end(addr, end)						\
106 ({	unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;	\
107 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
108 })
109 
110 #define pmd_cont_addr_end(addr, end)						\
111 ({	unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;	\
112 	(__boundary - 1 < (end) - 1) ? __boundary : (end);			\
113 })
114 
115 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
116 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
117 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
118 
119 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
120 /*
121  * Execute-only user mappings do not have the PTE_USER bit set. All valid
122  * kernel mappings have the PTE_UXN bit set.
123  */
124 #define pte_valid_not_user(pte) \
125 	((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
126 /*
127  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
128  * so that we don't erroneously return false for pages that have been
129  * remapped as PROT_NONE but are yet to be flushed from the TLB.
130  * Note that we can't make any assumptions based on the state of the access
131  * flag, since ptep_clear_flush_young() elides a DSB when invalidating the
132  * TLB.
133  */
134 #define pte_accessible(mm, pte)	\
135 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
136 
137 /*
138  * p??_access_permitted() is true for valid user mappings (PTE_USER
139  * bit set, subject to the write permission check). For execute-only
140  * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits
141  * not set) must return false. PROT_NONE mappings do not have the
142  * PTE_VALID bit set.
143  */
144 #define pte_access_permitted(pte, write) \
145 	(((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte)))
146 #define pmd_access_permitted(pmd, write) \
147 	(pte_access_permitted(pmd_pte(pmd), (write)))
148 #define pud_access_permitted(pud, write) \
149 	(pte_access_permitted(pud_pte(pud), (write)))
150 
151 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
152 {
153 	pte_val(pte) &= ~pgprot_val(prot);
154 	return pte;
155 }
156 
157 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
158 {
159 	pte_val(pte) |= pgprot_val(prot);
160 	return pte;
161 }
162 
163 static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t prot)
164 {
165 	pmd_val(pmd) &= ~pgprot_val(prot);
166 	return pmd;
167 }
168 
169 static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot)
170 {
171 	pmd_val(pmd) |= pgprot_val(prot);
172 	return pmd;
173 }
174 
175 static inline pte_t pte_mkwrite(pte_t pte)
176 {
177 	pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
178 	pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
179 	return pte;
180 }
181 
182 static inline pte_t pte_mkclean(pte_t pte)
183 {
184 	pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
185 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
186 
187 	return pte;
188 }
189 
190 static inline pte_t pte_mkdirty(pte_t pte)
191 {
192 	pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
193 
194 	if (pte_write(pte))
195 		pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
196 
197 	return pte;
198 }
199 
200 static inline pte_t pte_wrprotect(pte_t pte)
201 {
202 	/*
203 	 * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
204 	 * clear), set the PTE_DIRTY bit.
205 	 */
206 	if (pte_hw_dirty(pte))
207 		pte = pte_mkdirty(pte);
208 
209 	pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
210 	pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
211 	return pte;
212 }
213 
214 static inline pte_t pte_mkold(pte_t pte)
215 {
216 	return clear_pte_bit(pte, __pgprot(PTE_AF));
217 }
218 
219 static inline pte_t pte_mkyoung(pte_t pte)
220 {
221 	return set_pte_bit(pte, __pgprot(PTE_AF));
222 }
223 
224 static inline pte_t pte_mkspecial(pte_t pte)
225 {
226 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
227 }
228 
229 static inline pte_t pte_mkcont(pte_t pte)
230 {
231 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
232 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
233 }
234 
235 static inline pte_t pte_mknoncont(pte_t pte)
236 {
237 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
238 }
239 
240 static inline pte_t pte_mkpresent(pte_t pte)
241 {
242 	return set_pte_bit(pte, __pgprot(PTE_VALID));
243 }
244 
245 static inline pmd_t pmd_mkcont(pmd_t pmd)
246 {
247 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
248 }
249 
250 static inline pte_t pte_mkdevmap(pte_t pte)
251 {
252 	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));
253 }
254 
255 static inline void set_pte(pte_t *ptep, pte_t pte)
256 {
257 	WRITE_ONCE(*ptep, pte);
258 
259 	/*
260 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
261 	 * or update_mmu_cache() have the necessary barriers.
262 	 */
263 	if (pte_valid_not_user(pte)) {
264 		dsb(ishst);
265 		isb();
266 	}
267 }
268 
269 extern void __sync_icache_dcache(pte_t pteval);
270 
271 /*
272  * PTE bits configuration in the presence of hardware Dirty Bit Management
273  * (PTE_WRITE == PTE_DBM):
274  *
275  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
276  *   0      0      |   1           0          0
277  *   0      1      |   1           1          0
278  *   1      0      |   1           0          1
279  *   1      1      |   0           1          x
280  *
281  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
282  * the page fault mechanism. Checking the dirty status of a pte becomes:
283  *
284  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
285  */
286 
287 static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep,
288 					   pte_t pte)
289 {
290 	pte_t old_pte;
291 
292 	if (!IS_ENABLED(CONFIG_DEBUG_VM))
293 		return;
294 
295 	old_pte = READ_ONCE(*ptep);
296 
297 	if (!pte_valid(old_pte) || !pte_valid(pte))
298 		return;
299 	if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1)
300 		return;
301 
302 	/*
303 	 * Check for potential race with hardware updates of the pte
304 	 * (ptep_set_access_flags safely changes valid ptes without going
305 	 * through an invalid entry).
306 	 */
307 	VM_WARN_ONCE(!pte_young(pte),
308 		     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
309 		     __func__, pte_val(old_pte), pte_val(pte));
310 	VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte),
311 		     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
312 		     __func__, pte_val(old_pte), pte_val(pte));
313 }
314 
315 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
316 			      pte_t *ptep, pte_t pte)
317 {
318 	if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
319 		__sync_icache_dcache(pte);
320 
321 	/*
322 	 * If the PTE would provide user space access to the tags associated
323 	 * with it then ensure that the MTE tags are synchronised.  Although
324 	 * pte_access_permitted() returns false for exec only mappings, they
325 	 * don't expose tags (instruction fetches don't check tags).
326 	 */
327 	if (system_supports_mte() && pte_access_permitted(pte, false) &&
328 	    !pte_special(pte)) {
329 		pte_t old_pte = READ_ONCE(*ptep);
330 		/*
331 		 * We only need to synchronise if the new PTE has tags enabled
332 		 * or if swapping in (in which case another mapping may have
333 		 * set tags in the past even if this PTE isn't tagged).
334 		 * (!pte_none() && !pte_present()) is an open coded version of
335 		 * is_swap_pte()
336 		 */
337 		if (pte_tagged(pte) || (!pte_none(old_pte) && !pte_present(old_pte)))
338 			mte_sync_tags(old_pte, pte);
339 	}
340 
341 	__check_racy_pte_update(mm, ptep, pte);
342 
343 	set_pte(ptep, pte);
344 }
345 
346 /*
347  * Huge pte definitions.
348  */
349 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
350 
351 /*
352  * Hugetlb definitions.
353  */
354 #define HUGE_MAX_HSTATE		4
355 #define HPAGE_SHIFT		PMD_SHIFT
356 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
357 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
358 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
359 
360 static inline pte_t pgd_pte(pgd_t pgd)
361 {
362 	return __pte(pgd_val(pgd));
363 }
364 
365 static inline pte_t p4d_pte(p4d_t p4d)
366 {
367 	return __pte(p4d_val(p4d));
368 }
369 
370 static inline pte_t pud_pte(pud_t pud)
371 {
372 	return __pte(pud_val(pud));
373 }
374 
375 static inline pud_t pte_pud(pte_t pte)
376 {
377 	return __pud(pte_val(pte));
378 }
379 
380 static inline pmd_t pud_pmd(pud_t pud)
381 {
382 	return __pmd(pud_val(pud));
383 }
384 
385 static inline pte_t pmd_pte(pmd_t pmd)
386 {
387 	return __pte(pmd_val(pmd));
388 }
389 
390 static inline pmd_t pte_pmd(pte_t pte)
391 {
392 	return __pmd(pte_val(pte));
393 }
394 
395 static inline pgprot_t mk_pud_sect_prot(pgprot_t prot)
396 {
397 	return __pgprot((pgprot_val(prot) & ~PUD_TABLE_BIT) | PUD_TYPE_SECT);
398 }
399 
400 static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot)
401 {
402 	return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT);
403 }
404 
405 #ifdef CONFIG_NUMA_BALANCING
406 /*
407  * See the comment in include/linux/pgtable.h
408  */
409 static inline int pte_protnone(pte_t pte)
410 {
411 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
412 }
413 
414 static inline int pmd_protnone(pmd_t pmd)
415 {
416 	return pte_protnone(pmd_pte(pmd));
417 }
418 #endif
419 
420 #define pmd_present_invalid(pmd)     (!!(pmd_val(pmd) & PMD_PRESENT_INVALID))
421 
422 static inline int pmd_present(pmd_t pmd)
423 {
424 	return pte_present(pmd_pte(pmd)) || pmd_present_invalid(pmd);
425 }
426 
427 /*
428  * THP definitions.
429  */
430 
431 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
432 static inline int pmd_trans_huge(pmd_t pmd)
433 {
434 	return pmd_val(pmd) && pmd_present(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
435 }
436 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
437 
438 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
439 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
440 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
441 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
442 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
443 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
444 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
445 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
446 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
447 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
448 
449 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
450 {
451 	pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID));
452 	pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID));
453 
454 	return pmd;
455 }
456 
457 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
458 
459 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
460 
461 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
462 
463 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
464 #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
465 #endif
466 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
467 {
468 	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
469 }
470 
471 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
472 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
473 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
474 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
475 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
476 
477 #define pud_young(pud)		pte_young(pud_pte(pud))
478 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
479 #define pud_write(pud)		pte_write(pud_pte(pud))
480 
481 #define pud_mkhuge(pud)		(__pud(pud_val(pud) & ~PUD_TABLE_BIT))
482 
483 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
484 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
485 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
486 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
487 
488 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
489 #define set_pud_at(mm, addr, pudp, pud)	set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud))
490 
491 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
492 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
493 
494 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
495 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
496 
497 #define __pgprot_modify(prot,mask,bits) \
498 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
499 
500 #define pgprot_nx(prot) \
501 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
502 
503 /*
504  * Mark the prot value as uncacheable and unbufferable.
505  */
506 #define pgprot_noncached(prot) \
507 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
508 #define pgprot_writecombine(prot) \
509 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
510 #define pgprot_device(prot) \
511 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
512 #define pgprot_tagged(prot) \
513 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
514 #define pgprot_mhp	pgprot_tagged
515 /*
516  * DMA allocations for non-coherent devices use what the Arm architecture calls
517  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
518  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
519  * is intended for MMIO and thus forbids speculation, preserves access size,
520  * requires strict alignment and can also force write responses to come from the
521  * endpoint.
522  */
523 #define pgprot_dmacoherent(prot) \
524 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
525 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
526 
527 #define __HAVE_PHYS_MEM_ACCESS_PROT
528 struct file;
529 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
530 				     unsigned long size, pgprot_t vma_prot);
531 
532 #define pmd_none(pmd)		(!pmd_val(pmd))
533 
534 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
535 				 PMD_TYPE_TABLE)
536 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
537 				 PMD_TYPE_SECT)
538 #define pmd_leaf(pmd)		pmd_sect(pmd)
539 #define pmd_bad(pmd)		(!pmd_table(pmd))
540 
541 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
542 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
543 
544 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
545 static inline bool pud_sect(pud_t pud) { return false; }
546 static inline bool pud_table(pud_t pud) { return true; }
547 #else
548 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
549 				 PUD_TYPE_SECT)
550 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
551 				 PUD_TYPE_TABLE)
552 #endif
553 
554 extern pgd_t init_pg_dir[PTRS_PER_PGD];
555 extern pgd_t init_pg_end[];
556 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
557 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
558 extern pgd_t idmap_pg_end[];
559 extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
560 extern pgd_t reserved_pg_dir[PTRS_PER_PGD];
561 
562 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
563 
564 static inline bool in_swapper_pgdir(void *addr)
565 {
566 	return ((unsigned long)addr & PAGE_MASK) ==
567 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
568 }
569 
570 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
571 {
572 #ifdef __PAGETABLE_PMD_FOLDED
573 	if (in_swapper_pgdir(pmdp)) {
574 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
575 		return;
576 	}
577 #endif /* __PAGETABLE_PMD_FOLDED */
578 
579 	WRITE_ONCE(*pmdp, pmd);
580 
581 	if (pmd_valid(pmd)) {
582 		dsb(ishst);
583 		isb();
584 	}
585 }
586 
587 static inline void pmd_clear(pmd_t *pmdp)
588 {
589 	set_pmd(pmdp, __pmd(0));
590 }
591 
592 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
593 {
594 	return __pmd_to_phys(pmd);
595 }
596 
597 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
598 {
599 	return (unsigned long)__va(pmd_page_paddr(pmd));
600 }
601 
602 /* Find an entry in the third-level page table. */
603 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
604 
605 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
606 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
607 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
608 
609 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
610 
611 /* use ONLY for statically allocated translation tables */
612 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
613 
614 /*
615  * Conversion functions: convert a page and protection to a page entry,
616  * and a page entry and page directory to the page they refer to.
617  */
618 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
619 
620 #if CONFIG_PGTABLE_LEVELS > 2
621 
622 #define pmd_ERROR(e)	\
623 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
624 
625 #define pud_none(pud)		(!pud_val(pud))
626 #define pud_bad(pud)		(!pud_table(pud))
627 #define pud_present(pud)	pte_present(pud_pte(pud))
628 #define pud_leaf(pud)		pud_sect(pud)
629 #define pud_valid(pud)		pte_valid(pud_pte(pud))
630 
631 static inline void set_pud(pud_t *pudp, pud_t pud)
632 {
633 #ifdef __PAGETABLE_PUD_FOLDED
634 	if (in_swapper_pgdir(pudp)) {
635 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
636 		return;
637 	}
638 #endif /* __PAGETABLE_PUD_FOLDED */
639 
640 	WRITE_ONCE(*pudp, pud);
641 
642 	if (pud_valid(pud)) {
643 		dsb(ishst);
644 		isb();
645 	}
646 }
647 
648 static inline void pud_clear(pud_t *pudp)
649 {
650 	set_pud(pudp, __pud(0));
651 }
652 
653 static inline phys_addr_t pud_page_paddr(pud_t pud)
654 {
655 	return __pud_to_phys(pud);
656 }
657 
658 static inline pmd_t *pud_pgtable(pud_t pud)
659 {
660 	return (pmd_t *)__va(pud_page_paddr(pud));
661 }
662 
663 /* Find an entry in the second-level page table. */
664 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
665 
666 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
667 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
668 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
669 
670 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
671 
672 /* use ONLY for statically allocated translation tables */
673 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
674 
675 #else
676 
677 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
678 
679 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
680 #define pmd_set_fixmap(addr)		NULL
681 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
682 #define pmd_clear_fixmap()
683 
684 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
685 
686 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
687 
688 #if CONFIG_PGTABLE_LEVELS > 3
689 
690 #define pud_ERROR(e)	\
691 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
692 
693 #define p4d_none(p4d)		(!p4d_val(p4d))
694 #define p4d_bad(p4d)		(!(p4d_val(p4d) & 2))
695 #define p4d_present(p4d)	(p4d_val(p4d))
696 
697 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
698 {
699 	if (in_swapper_pgdir(p4dp)) {
700 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
701 		return;
702 	}
703 
704 	WRITE_ONCE(*p4dp, p4d);
705 	dsb(ishst);
706 	isb();
707 }
708 
709 static inline void p4d_clear(p4d_t *p4dp)
710 {
711 	set_p4d(p4dp, __p4d(0));
712 }
713 
714 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
715 {
716 	return __p4d_to_phys(p4d);
717 }
718 
719 static inline pud_t *p4d_pgtable(p4d_t p4d)
720 {
721 	return (pud_t *)__va(p4d_page_paddr(p4d));
722 }
723 
724 /* Find an entry in the first-level page table. */
725 #define pud_offset_phys(dir, addr)	(p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t))
726 
727 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
728 #define pud_set_fixmap_offset(p4d, addr)	pud_set_fixmap(pud_offset_phys(p4d, addr))
729 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
730 
731 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
732 
733 /* use ONLY for statically allocated translation tables */
734 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
735 
736 #else
737 
738 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
739 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
740 
741 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
742 #define pud_set_fixmap(addr)		NULL
743 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
744 #define pud_clear_fixmap()
745 
746 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
747 
748 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
749 
750 #define pgd_ERROR(e)	\
751 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
752 
753 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
754 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
755 
756 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
757 {
758 	/*
759 	 * Normal and Normal-Tagged are two different memory types and indices
760 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
761 	 */
762 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
763 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP |
764 			      PTE_ATTRINDX_MASK;
765 	/* preserve the hardware dirty information */
766 	if (pte_hw_dirty(pte))
767 		pte = pte_mkdirty(pte);
768 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
769 	return pte;
770 }
771 
772 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
773 {
774 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
775 }
776 
777 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
778 extern int ptep_set_access_flags(struct vm_area_struct *vma,
779 				 unsigned long address, pte_t *ptep,
780 				 pte_t entry, int dirty);
781 
782 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
783 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
784 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
785 					unsigned long address, pmd_t *pmdp,
786 					pmd_t entry, int dirty)
787 {
788 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
789 }
790 
791 static inline int pud_devmap(pud_t pud)
792 {
793 	return 0;
794 }
795 
796 static inline int pgd_devmap(pgd_t pgd)
797 {
798 	return 0;
799 }
800 #endif
801 
802 /*
803  * Atomic pte/pmd modifications.
804  */
805 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
806 static inline int __ptep_test_and_clear_young(pte_t *ptep)
807 {
808 	pte_t old_pte, pte;
809 
810 	pte = READ_ONCE(*ptep);
811 	do {
812 		old_pte = pte;
813 		pte = pte_mkold(pte);
814 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
815 					       pte_val(old_pte), pte_val(pte));
816 	} while (pte_val(pte) != pte_val(old_pte));
817 
818 	return pte_young(pte);
819 }
820 
821 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
822 					    unsigned long address,
823 					    pte_t *ptep)
824 {
825 	return __ptep_test_and_clear_young(ptep);
826 }
827 
828 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
829 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
830 					 unsigned long address, pte_t *ptep)
831 {
832 	int young = ptep_test_and_clear_young(vma, address, ptep);
833 
834 	if (young) {
835 		/*
836 		 * We can elide the trailing DSB here since the worst that can
837 		 * happen is that a CPU continues to use the young entry in its
838 		 * TLB and we mistakenly reclaim the associated page. The
839 		 * window for such an event is bounded by the next
840 		 * context-switch, which provides a DSB to complete the TLB
841 		 * invalidation.
842 		 */
843 		flush_tlb_page_nosync(vma, address);
844 	}
845 
846 	return young;
847 }
848 
849 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
850 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
851 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
852 					    unsigned long address,
853 					    pmd_t *pmdp)
854 {
855 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
856 }
857 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
858 
859 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
860 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
861 				       unsigned long address, pte_t *ptep)
862 {
863 	return __pte(xchg_relaxed(&pte_val(*ptep), 0));
864 }
865 
866 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
867 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
868 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
869 					    unsigned long address, pmd_t *pmdp)
870 {
871 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
872 }
873 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
874 
875 /*
876  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
877  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
878  */
879 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
880 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
881 {
882 	pte_t old_pte, pte;
883 
884 	pte = READ_ONCE(*ptep);
885 	do {
886 		old_pte = pte;
887 		pte = pte_wrprotect(pte);
888 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
889 					       pte_val(old_pte), pte_val(pte));
890 	} while (pte_val(pte) != pte_val(old_pte));
891 }
892 
893 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
894 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
895 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
896 				      unsigned long address, pmd_t *pmdp)
897 {
898 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
899 }
900 
901 #define pmdp_establish pmdp_establish
902 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
903 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
904 {
905 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
906 }
907 #endif
908 
909 /*
910  * Encode and decode a swap entry:
911  *	bits 0-1:	present (must be zero)
912  *	bits 2-7:	swap type
913  *	bits 8-57:	swap offset
914  *	bit  58:	PTE_PROT_NONE (must be zero)
915  */
916 #define __SWP_TYPE_SHIFT	2
917 #define __SWP_TYPE_BITS		6
918 #define __SWP_OFFSET_BITS	50
919 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
920 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
921 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
922 
923 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
924 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
925 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
926 
927 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
928 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
929 
930 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
931 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
932 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
933 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
934 
935 /*
936  * Ensure that there are not more swap files than can be encoded in the kernel
937  * PTEs.
938  */
939 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
940 
941 extern int kern_addr_valid(unsigned long addr);
942 
943 #ifdef CONFIG_ARM64_MTE
944 
945 #define __HAVE_ARCH_PREPARE_TO_SWAP
946 static inline int arch_prepare_to_swap(struct page *page)
947 {
948 	if (system_supports_mte())
949 		return mte_save_tags(page);
950 	return 0;
951 }
952 
953 #define __HAVE_ARCH_SWAP_INVALIDATE
954 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
955 {
956 	if (system_supports_mte())
957 		mte_invalidate_tags(type, offset);
958 }
959 
960 static inline void arch_swap_invalidate_area(int type)
961 {
962 	if (system_supports_mte())
963 		mte_invalidate_tags_area(type);
964 }
965 
966 #define __HAVE_ARCH_SWAP_RESTORE
967 static inline void arch_swap_restore(swp_entry_t entry, struct page *page)
968 {
969 	if (system_supports_mte() && mte_restore_tags(entry, page))
970 		set_bit(PG_mte_tagged, &page->flags);
971 }
972 
973 #endif /* CONFIG_ARM64_MTE */
974 
975 /*
976  * On AArch64, the cache coherency is handled via the set_pte_at() function.
977  */
978 static inline void update_mmu_cache(struct vm_area_struct *vma,
979 				    unsigned long addr, pte_t *ptep)
980 {
981 	/*
982 	 * We don't do anything here, so there's a very small chance of
983 	 * us retaking a user fault which we just fixed up. The alternative
984 	 * is doing a dsb(ishst), but that penalises the fastpath.
985 	 */
986 }
987 
988 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
989 
990 #ifdef CONFIG_ARM64_PA_BITS_52
991 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
992 #else
993 #define phys_to_ttbr(addr)	(addr)
994 #endif
995 
996 /*
997  * On arm64 without hardware Access Flag, copying from user will fail because
998  * the pte is old and cannot be marked young. So we always end up with zeroed
999  * page after fork() + CoW for pfn mappings. We don't always have a
1000  * hardware-managed access flag on arm64.
1001  */
1002 static inline bool arch_faults_on_old_pte(void)
1003 {
1004 	WARN_ON(preemptible());
1005 
1006 	return !cpu_has_hw_af();
1007 }
1008 #define arch_faults_on_old_pte		arch_faults_on_old_pte
1009 
1010 /*
1011  * Experimentally, it's cheap to set the access flag in hardware and we
1012  * benefit from prefaulting mappings as 'old' to start with.
1013  */
1014 static inline bool arch_wants_old_prefaulted_pte(void)
1015 {
1016 	return !arch_faults_on_old_pte();
1017 }
1018 #define arch_wants_old_prefaulted_pte	arch_wants_old_prefaulted_pte
1019 
1020 static inline bool pud_sect_supported(void)
1021 {
1022 	return PAGE_SIZE == SZ_4K;
1023 }
1024 
1025 
1026 #endif /* !__ASSEMBLY__ */
1027 
1028 #endif /* __ASM_PGTABLE_H */
1029