xref: /openbmc/linux/arch/arm64/include/asm/pgtable.h (revision 2fe60ec9)
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 #define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
406 static inline pte_t pte_swp_mkexclusive(pte_t pte)
407 {
408 	return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
409 }
410 
411 static inline int pte_swp_exclusive(pte_t pte)
412 {
413 	return pte_val(pte) & PTE_SWP_EXCLUSIVE;
414 }
415 
416 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
417 {
418 	return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE));
419 }
420 
421 #ifdef CONFIG_NUMA_BALANCING
422 /*
423  * See the comment in include/linux/pgtable.h
424  */
425 static inline int pte_protnone(pte_t pte)
426 {
427 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
428 }
429 
430 static inline int pmd_protnone(pmd_t pmd)
431 {
432 	return pte_protnone(pmd_pte(pmd));
433 }
434 #endif
435 
436 #define pmd_present_invalid(pmd)     (!!(pmd_val(pmd) & PMD_PRESENT_INVALID))
437 
438 static inline int pmd_present(pmd_t pmd)
439 {
440 	return pte_present(pmd_pte(pmd)) || pmd_present_invalid(pmd);
441 }
442 
443 /*
444  * THP definitions.
445  */
446 
447 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
448 static inline int pmd_trans_huge(pmd_t pmd)
449 {
450 	return pmd_val(pmd) && pmd_present(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
451 }
452 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
453 
454 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
455 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
456 #define pmd_valid(pmd)		pte_valid(pmd_pte(pmd))
457 #define pmd_cont(pmd)		pte_cont(pmd_pte(pmd))
458 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
459 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
460 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
461 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
462 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
463 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
464 
465 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
466 {
467 	pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID));
468 	pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID));
469 
470 	return pmd;
471 }
472 
473 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
474 
475 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
476 
477 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
478 
479 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
480 #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
481 #endif
482 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
483 {
484 	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
485 }
486 
487 #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
488 #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)
489 #define pmd_pfn(pmd)		((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
490 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
491 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
492 
493 #define pud_young(pud)		pte_young(pud_pte(pud))
494 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
495 #define pud_write(pud)		pte_write(pud_pte(pud))
496 
497 #define pud_mkhuge(pud)		(__pud(pud_val(pud) & ~PUD_TABLE_BIT))
498 
499 #define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))
500 #define __phys_to_pud_val(phys)	__phys_to_pte_val(phys)
501 #define pud_pfn(pud)		((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT)
502 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
503 
504 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
505 #define set_pud_at(mm, addr, pudp, pud)	set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud))
506 
507 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
508 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
509 
510 #define __pgd_to_phys(pgd)	__pte_to_phys(pgd_pte(pgd))
511 #define __phys_to_pgd_val(phys)	__phys_to_pte_val(phys)
512 
513 #define __pgprot_modify(prot,mask,bits) \
514 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
515 
516 #define pgprot_nx(prot) \
517 	__pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN)
518 
519 /*
520  * Mark the prot value as uncacheable and unbufferable.
521  */
522 #define pgprot_noncached(prot) \
523 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
524 #define pgprot_writecombine(prot) \
525 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
526 #define pgprot_device(prot) \
527 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
528 #define pgprot_tagged(prot) \
529 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
530 #define pgprot_mhp	pgprot_tagged
531 /*
532  * DMA allocations for non-coherent devices use what the Arm architecture calls
533  * "Normal non-cacheable" memory, which permits speculation, unaligned accesses
534  * and merging of writes.  This is different from "Device-nGnR[nE]" memory which
535  * is intended for MMIO and thus forbids speculation, preserves access size,
536  * requires strict alignment and can also force write responses to come from the
537  * endpoint.
538  */
539 #define pgprot_dmacoherent(prot) \
540 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
541 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
542 
543 #define __HAVE_PHYS_MEM_ACCESS_PROT
544 struct file;
545 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
546 				     unsigned long size, pgprot_t vma_prot);
547 
548 #define pmd_none(pmd)		(!pmd_val(pmd))
549 
550 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
551 				 PMD_TYPE_TABLE)
552 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
553 				 PMD_TYPE_SECT)
554 #define pmd_leaf(pmd)		(pmd_present(pmd) && !pmd_table(pmd))
555 #define pmd_bad(pmd)		(!pmd_table(pmd))
556 
557 #define pmd_leaf_size(pmd)	(pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
558 #define pte_leaf_size(pte)	(pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE)
559 
560 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
561 static inline bool pud_sect(pud_t pud) { return false; }
562 static inline bool pud_table(pud_t pud) { return true; }
563 #else
564 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
565 				 PUD_TYPE_SECT)
566 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
567 				 PUD_TYPE_TABLE)
568 #endif
569 
570 extern pgd_t init_pg_dir[PTRS_PER_PGD];
571 extern pgd_t init_pg_end[];
572 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
573 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
574 extern pgd_t idmap_pg_end[];
575 extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
576 extern pgd_t reserved_pg_dir[PTRS_PER_PGD];
577 
578 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd);
579 
580 static inline bool in_swapper_pgdir(void *addr)
581 {
582 	return ((unsigned long)addr & PAGE_MASK) ==
583 	        ((unsigned long)swapper_pg_dir & PAGE_MASK);
584 }
585 
586 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
587 {
588 #ifdef __PAGETABLE_PMD_FOLDED
589 	if (in_swapper_pgdir(pmdp)) {
590 		set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd)));
591 		return;
592 	}
593 #endif /* __PAGETABLE_PMD_FOLDED */
594 
595 	WRITE_ONCE(*pmdp, pmd);
596 
597 	if (pmd_valid(pmd)) {
598 		dsb(ishst);
599 		isb();
600 	}
601 }
602 
603 static inline void pmd_clear(pmd_t *pmdp)
604 {
605 	set_pmd(pmdp, __pmd(0));
606 }
607 
608 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
609 {
610 	return __pmd_to_phys(pmd);
611 }
612 
613 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
614 {
615 	return (unsigned long)__va(pmd_page_paddr(pmd));
616 }
617 
618 /* Find an entry in the third-level page table. */
619 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
620 
621 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
622 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
623 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
624 
625 #define pmd_page(pmd)			phys_to_page(__pmd_to_phys(pmd))
626 
627 /* use ONLY for statically allocated translation tables */
628 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
629 
630 /*
631  * Conversion functions: convert a page and protection to a page entry,
632  * and a page entry and page directory to the page they refer to.
633  */
634 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
635 
636 #if CONFIG_PGTABLE_LEVELS > 2
637 
638 #define pmd_ERROR(e)	\
639 	pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
640 
641 #define pud_none(pud)		(!pud_val(pud))
642 #define pud_bad(pud)		(!pud_table(pud))
643 #define pud_present(pud)	pte_present(pud_pte(pud))
644 #define pud_leaf(pud)		(pud_present(pud) && !pud_table(pud))
645 #define pud_valid(pud)		pte_valid(pud_pte(pud))
646 
647 static inline void set_pud(pud_t *pudp, pud_t pud)
648 {
649 #ifdef __PAGETABLE_PUD_FOLDED
650 	if (in_swapper_pgdir(pudp)) {
651 		set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud)));
652 		return;
653 	}
654 #endif /* __PAGETABLE_PUD_FOLDED */
655 
656 	WRITE_ONCE(*pudp, pud);
657 
658 	if (pud_valid(pud)) {
659 		dsb(ishst);
660 		isb();
661 	}
662 }
663 
664 static inline void pud_clear(pud_t *pudp)
665 {
666 	set_pud(pudp, __pud(0));
667 }
668 
669 static inline phys_addr_t pud_page_paddr(pud_t pud)
670 {
671 	return __pud_to_phys(pud);
672 }
673 
674 static inline pmd_t *pud_pgtable(pud_t pud)
675 {
676 	return (pmd_t *)__va(pud_page_paddr(pud));
677 }
678 
679 /* Find an entry in the second-level page table. */
680 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
681 
682 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
683 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
684 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
685 
686 #define pud_page(pud)			phys_to_page(__pud_to_phys(pud))
687 
688 /* use ONLY for statically allocated translation tables */
689 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
690 
691 #else
692 
693 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
694 
695 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
696 #define pmd_set_fixmap(addr)		NULL
697 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
698 #define pmd_clear_fixmap()
699 
700 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
701 
702 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
703 
704 #if CONFIG_PGTABLE_LEVELS > 3
705 
706 #define pud_ERROR(e)	\
707 	pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e))
708 
709 #define p4d_none(p4d)		(!p4d_val(p4d))
710 #define p4d_bad(p4d)		(!(p4d_val(p4d) & 2))
711 #define p4d_present(p4d)	(p4d_val(p4d))
712 
713 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
714 {
715 	if (in_swapper_pgdir(p4dp)) {
716 		set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d)));
717 		return;
718 	}
719 
720 	WRITE_ONCE(*p4dp, p4d);
721 	dsb(ishst);
722 	isb();
723 }
724 
725 static inline void p4d_clear(p4d_t *p4dp)
726 {
727 	set_p4d(p4dp, __p4d(0));
728 }
729 
730 static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
731 {
732 	return __p4d_to_phys(p4d);
733 }
734 
735 static inline pud_t *p4d_pgtable(p4d_t p4d)
736 {
737 	return (pud_t *)__va(p4d_page_paddr(p4d));
738 }
739 
740 /* Find an entry in the first-level page table. */
741 #define pud_offset_phys(dir, addr)	(p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t))
742 
743 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
744 #define pud_set_fixmap_offset(p4d, addr)	pud_set_fixmap(pud_offset_phys(p4d, addr))
745 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
746 
747 #define p4d_page(p4d)		pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d)))
748 
749 /* use ONLY for statically allocated translation tables */
750 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
751 
752 #else
753 
754 #define p4d_page_paddr(p4d)	({ BUILD_BUG(); 0;})
755 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
756 
757 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
758 #define pud_set_fixmap(addr)		NULL
759 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
760 #define pud_clear_fixmap()
761 
762 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
763 
764 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
765 
766 #define pgd_ERROR(e)	\
767 	pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
768 
769 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
770 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
771 
772 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
773 {
774 	/*
775 	 * Normal and Normal-Tagged are two different memory types and indices
776 	 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK.
777 	 */
778 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
779 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP |
780 			      PTE_ATTRINDX_MASK;
781 	/* preserve the hardware dirty information */
782 	if (pte_hw_dirty(pte))
783 		pte = pte_mkdirty(pte);
784 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
785 	return pte;
786 }
787 
788 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
789 {
790 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
791 }
792 
793 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
794 extern int ptep_set_access_flags(struct vm_area_struct *vma,
795 				 unsigned long address, pte_t *ptep,
796 				 pte_t entry, int dirty);
797 
798 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
799 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
800 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
801 					unsigned long address, pmd_t *pmdp,
802 					pmd_t entry, int dirty)
803 {
804 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
805 }
806 
807 static inline int pud_devmap(pud_t pud)
808 {
809 	return 0;
810 }
811 
812 static inline int pgd_devmap(pgd_t pgd)
813 {
814 	return 0;
815 }
816 #endif
817 
818 /*
819  * Atomic pte/pmd modifications.
820  */
821 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
822 static inline int __ptep_test_and_clear_young(pte_t *ptep)
823 {
824 	pte_t old_pte, pte;
825 
826 	pte = READ_ONCE(*ptep);
827 	do {
828 		old_pte = pte;
829 		pte = pte_mkold(pte);
830 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
831 					       pte_val(old_pte), pte_val(pte));
832 	} while (pte_val(pte) != pte_val(old_pte));
833 
834 	return pte_young(pte);
835 }
836 
837 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
838 					    unsigned long address,
839 					    pte_t *ptep)
840 {
841 	return __ptep_test_and_clear_young(ptep);
842 }
843 
844 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
845 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
846 					 unsigned long address, pte_t *ptep)
847 {
848 	int young = ptep_test_and_clear_young(vma, address, ptep);
849 
850 	if (young) {
851 		/*
852 		 * We can elide the trailing DSB here since the worst that can
853 		 * happen is that a CPU continues to use the young entry in its
854 		 * TLB and we mistakenly reclaim the associated page. The
855 		 * window for such an event is bounded by the next
856 		 * context-switch, which provides a DSB to complete the TLB
857 		 * invalidation.
858 		 */
859 		flush_tlb_page_nosync(vma, address);
860 	}
861 
862 	return young;
863 }
864 
865 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
866 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
867 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
868 					    unsigned long address,
869 					    pmd_t *pmdp)
870 {
871 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
872 }
873 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
874 
875 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
876 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
877 				       unsigned long address, pte_t *ptep)
878 {
879 	return __pte(xchg_relaxed(&pte_val(*ptep), 0));
880 }
881 
882 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
883 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
884 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
885 					    unsigned long address, pmd_t *pmdp)
886 {
887 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
888 }
889 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
890 
891 /*
892  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
893  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
894  */
895 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
896 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
897 {
898 	pte_t old_pte, pte;
899 
900 	pte = READ_ONCE(*ptep);
901 	do {
902 		old_pte = pte;
903 		pte = pte_wrprotect(pte);
904 		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
905 					       pte_val(old_pte), pte_val(pte));
906 	} while (pte_val(pte) != pte_val(old_pte));
907 }
908 
909 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
910 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
911 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
912 				      unsigned long address, pmd_t *pmdp)
913 {
914 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
915 }
916 
917 #define pmdp_establish pmdp_establish
918 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
919 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
920 {
921 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
922 }
923 #endif
924 
925 /*
926  * Encode and decode a swap entry:
927  *	bits 0-1:	present (must be zero)
928  *	bits 2:		remember PG_anon_exclusive
929  *	bits 3-7:	swap type
930  *	bits 8-57:	swap offset
931  *	bit  58:	PTE_PROT_NONE (must be zero)
932  */
933 #define __SWP_TYPE_SHIFT	3
934 #define __SWP_TYPE_BITS		5
935 #define __SWP_OFFSET_BITS	50
936 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
937 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
938 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
939 
940 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
941 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
942 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
943 
944 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
945 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
946 
947 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
948 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val(pmd) })
949 #define __swp_entry_to_pmd(swp)		__pmd((swp).val)
950 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
951 
952 /*
953  * Ensure that there are not more swap files than can be encoded in the kernel
954  * PTEs.
955  */
956 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
957 
958 extern int kern_addr_valid(unsigned long addr);
959 
960 #ifdef CONFIG_ARM64_MTE
961 
962 #define __HAVE_ARCH_PREPARE_TO_SWAP
963 static inline int arch_prepare_to_swap(struct page *page)
964 {
965 	if (system_supports_mte())
966 		return mte_save_tags(page);
967 	return 0;
968 }
969 
970 #define __HAVE_ARCH_SWAP_INVALIDATE
971 static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
972 {
973 	if (system_supports_mte())
974 		mte_invalidate_tags(type, offset);
975 }
976 
977 static inline void arch_swap_invalidate_area(int type)
978 {
979 	if (system_supports_mte())
980 		mte_invalidate_tags_area(type);
981 }
982 
983 #define __HAVE_ARCH_SWAP_RESTORE
984 static inline void arch_swap_restore(swp_entry_t entry, struct page *page)
985 {
986 	if (system_supports_mte() && mte_restore_tags(entry, page))
987 		set_bit(PG_mte_tagged, &page->flags);
988 }
989 
990 #endif /* CONFIG_ARM64_MTE */
991 
992 /*
993  * On AArch64, the cache coherency is handled via the set_pte_at() function.
994  */
995 static inline void update_mmu_cache(struct vm_area_struct *vma,
996 				    unsigned long addr, pte_t *ptep)
997 {
998 	/*
999 	 * We don't do anything here, so there's a very small chance of
1000 	 * us retaking a user fault which we just fixed up. The alternative
1001 	 * is doing a dsb(ishst), but that penalises the fastpath.
1002 	 */
1003 }
1004 
1005 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
1006 
1007 #ifdef CONFIG_ARM64_PA_BITS_52
1008 #define phys_to_ttbr(addr)	(((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52)
1009 #else
1010 #define phys_to_ttbr(addr)	(addr)
1011 #endif
1012 
1013 /*
1014  * On arm64 without hardware Access Flag, copying from user will fail because
1015  * the pte is old and cannot be marked young. So we always end up with zeroed
1016  * page after fork() + CoW for pfn mappings. We don't always have a
1017  * hardware-managed access flag on arm64.
1018  */
1019 static inline bool arch_faults_on_old_pte(void)
1020 {
1021 	WARN_ON(preemptible());
1022 
1023 	return !cpu_has_hw_af();
1024 }
1025 #define arch_faults_on_old_pte		arch_faults_on_old_pte
1026 
1027 /*
1028  * Experimentally, it's cheap to set the access flag in hardware and we
1029  * benefit from prefaulting mappings as 'old' to start with.
1030  */
1031 static inline bool arch_wants_old_prefaulted_pte(void)
1032 {
1033 	return !arch_faults_on_old_pte();
1034 }
1035 #define arch_wants_old_prefaulted_pte	arch_wants_old_prefaulted_pte
1036 
1037 static inline bool pud_sect_supported(void)
1038 {
1039 	return PAGE_SIZE == SZ_4K;
1040 }
1041 
1042 
1043 #endif /* !__ASSEMBLY__ */
1044 
1045 #endif /* __ASM_PGTABLE_H */
1046