xref: /linux/arch/arm64/include/asm/pgtable.h (revision b52f3ed02221252d8ee2c7d756e76fad4a5e84f6)
1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_PGTABLE_H
17 #define __ASM_PGTABLE_H
18 
19 #include <asm/bug.h>
20 #include <asm/proc-fns.h>
21 
22 #include <asm/memory.h>
23 #include <asm/pgtable-hwdef.h>
24 #include <asm/pgtable-prot.h>
25 
26 /*
27  * VMALLOC and SPARSEMEM_VMEMMAP ranges.
28  *
29  * VMEMAP_SIZE: allows the whole linear region to be covered by a struct page array
30  *	(rounded up to PUD_SIZE).
31  * VMALLOC_START: beginning of the kernel vmalloc space
32  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
33  *	fixed mappings and modules
34  */
35 #define VMEMMAP_SIZE		ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
36 
37 #define VMALLOC_START		(MODULES_END)
38 #define VMALLOC_END		(PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
39 
40 #define VMEMMAP_START		(VMALLOC_END + SZ_64K)
41 #define vmemmap			((struct page *)VMEMMAP_START - \
42 				 SECTION_ALIGN_DOWN(memstart_addr >> PAGE_SHIFT))
43 
44 #define FIRST_USER_ADDRESS	0UL
45 
46 #ifndef __ASSEMBLY__
47 
48 #include <asm/fixmap.h>
49 #include <linux/mmdebug.h>
50 
51 extern void __pte_error(const char *file, int line, unsigned long val);
52 extern void __pmd_error(const char *file, int line, unsigned long val);
53 extern void __pud_error(const char *file, int line, unsigned long val);
54 extern void __pgd_error(const char *file, int line, unsigned long val);
55 
56 /*
57  * ZERO_PAGE is a global shared page that is always zero: used
58  * for zero-mapped memory areas etc..
59  */
60 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
61 #define ZERO_PAGE(vaddr)	virt_to_page(empty_zero_page)
62 
63 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
64 
65 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
66 
67 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
68 
69 #define pte_none(pte)		(!pte_val(pte))
70 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
71 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
72 
73 /*
74  * The following only work if pte_present(). Undefined behaviour otherwise.
75  */
76 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
77 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
78 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
79 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
80 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
81 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
82 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
83 
84 #ifdef CONFIG_ARM64_HW_AFDBM
85 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
86 #else
87 #define pte_hw_dirty(pte)	(0)
88 #endif
89 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
90 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
91 
92 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
93 #define pte_valid_not_user(pte) \
94 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
95 #define pte_valid_young(pte) \
96 	((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
97 
98 /*
99  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
100  * so that we don't erroneously return false for pages that have been
101  * remapped as PROT_NONE but are yet to be flushed from the TLB.
102  */
103 #define pte_accessible(mm, pte)	\
104 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
105 
106 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
107 {
108 	pte_val(pte) &= ~pgprot_val(prot);
109 	return pte;
110 }
111 
112 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
113 {
114 	pte_val(pte) |= pgprot_val(prot);
115 	return pte;
116 }
117 
118 static inline pte_t pte_wrprotect(pte_t pte)
119 {
120 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
121 }
122 
123 static inline pte_t pte_mkwrite(pte_t pte)
124 {
125 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
126 }
127 
128 static inline pte_t pte_mkclean(pte_t pte)
129 {
130 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
131 }
132 
133 static inline pte_t pte_mkdirty(pte_t pte)
134 {
135 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
136 }
137 
138 static inline pte_t pte_mkold(pte_t pte)
139 {
140 	return clear_pte_bit(pte, __pgprot(PTE_AF));
141 }
142 
143 static inline pte_t pte_mkyoung(pte_t pte)
144 {
145 	return set_pte_bit(pte, __pgprot(PTE_AF));
146 }
147 
148 static inline pte_t pte_mkspecial(pte_t pte)
149 {
150 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
151 }
152 
153 static inline pte_t pte_mkcont(pte_t pte)
154 {
155 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
156 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
157 }
158 
159 static inline pte_t pte_mknoncont(pte_t pte)
160 {
161 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
162 }
163 
164 static inline pmd_t pmd_mkcont(pmd_t pmd)
165 {
166 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
167 }
168 
169 static inline void set_pte(pte_t *ptep, pte_t pte)
170 {
171 	*ptep = pte;
172 
173 	/*
174 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
175 	 * or update_mmu_cache() have the necessary barriers.
176 	 */
177 	if (pte_valid_not_user(pte)) {
178 		dsb(ishst);
179 		isb();
180 	}
181 }
182 
183 struct mm_struct;
184 struct vm_area_struct;
185 
186 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
187 
188 /*
189  * PTE bits configuration in the presence of hardware Dirty Bit Management
190  * (PTE_WRITE == PTE_DBM):
191  *
192  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
193  *   0      0      |   1           0          0
194  *   0      1      |   1           1          0
195  *   1      0      |   1           0          1
196  *   1      1      |   0           1          x
197  *
198  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
199  * the page fault mechanism. Checking the dirty status of a pte becomes:
200  *
201  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
202  */
203 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
204 			      pte_t *ptep, pte_t pte)
205 {
206 	if (pte_present(pte)) {
207 		if (pte_sw_dirty(pte) && pte_write(pte))
208 			pte_val(pte) &= ~PTE_RDONLY;
209 		else
210 			pte_val(pte) |= PTE_RDONLY;
211 		if (pte_user(pte) && pte_exec(pte) && !pte_special(pte))
212 			__sync_icache_dcache(pte, addr);
213 	}
214 
215 	/*
216 	 * If the existing pte is valid, check for potential race with
217 	 * hardware updates of the pte (ptep_set_access_flags safely changes
218 	 * valid ptes without going through an invalid entry).
219 	 */
220 	if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
221 	    pte_valid(*ptep) && pte_valid(pte)) {
222 		VM_WARN_ONCE(!pte_young(pte),
223 			     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
224 			     __func__, pte_val(*ptep), pte_val(pte));
225 		VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
226 			     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
227 			     __func__, pte_val(*ptep), pte_val(pte));
228 	}
229 
230 	set_pte(ptep, pte);
231 }
232 
233 /*
234  * Huge pte definitions.
235  */
236 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
237 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
238 
239 /*
240  * Hugetlb definitions.
241  */
242 #define HUGE_MAX_HSTATE		4
243 #define HPAGE_SHIFT		PMD_SHIFT
244 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
245 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
246 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
247 
248 #define __HAVE_ARCH_PTE_SPECIAL
249 
250 static inline pte_t pud_pte(pud_t pud)
251 {
252 	return __pte(pud_val(pud));
253 }
254 
255 static inline pmd_t pud_pmd(pud_t pud)
256 {
257 	return __pmd(pud_val(pud));
258 }
259 
260 static inline pte_t pmd_pte(pmd_t pmd)
261 {
262 	return __pte(pmd_val(pmd));
263 }
264 
265 static inline pmd_t pte_pmd(pte_t pte)
266 {
267 	return __pmd(pte_val(pte));
268 }
269 
270 static inline pgprot_t mk_sect_prot(pgprot_t prot)
271 {
272 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
273 }
274 
275 /*
276  * THP definitions.
277  */
278 
279 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
280 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
281 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
282 
283 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
284 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
285 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
286 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
287 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
288 #define pmd_mkclean(pmd)       pte_pmd(pte_mkclean(pmd_pte(pmd)))
289 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
290 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
291 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
292 
293 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
294 
295 #define __HAVE_ARCH_PMD_WRITE
296 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
297 
298 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
299 
300 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
301 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
302 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
303 
304 #define pud_write(pud)		pte_write(pud_pte(pud))
305 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
306 
307 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
308 
309 static inline int has_transparent_hugepage(void)
310 {
311 	return 1;
312 }
313 
314 #define __pgprot_modify(prot,mask,bits) \
315 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
316 
317 /*
318  * Mark the prot value as uncacheable and unbufferable.
319  */
320 #define pgprot_noncached(prot) \
321 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
322 #define pgprot_writecombine(prot) \
323 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
324 #define pgprot_device(prot) \
325 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
326 #define __HAVE_PHYS_MEM_ACCESS_PROT
327 struct file;
328 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
329 				     unsigned long size, pgprot_t vma_prot);
330 
331 #define pmd_none(pmd)		(!pmd_val(pmd))
332 #define pmd_present(pmd)	(pmd_val(pmd))
333 
334 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
335 
336 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
337 				 PMD_TYPE_TABLE)
338 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
339 				 PMD_TYPE_SECT)
340 
341 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
342 #define pud_sect(pud)		(0)
343 #define pud_table(pud)		(1)
344 #else
345 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
346 				 PUD_TYPE_SECT)
347 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
348 				 PUD_TYPE_TABLE)
349 #endif
350 
351 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
352 {
353 	*pmdp = pmd;
354 	dsb(ishst);
355 	isb();
356 }
357 
358 static inline void pmd_clear(pmd_t *pmdp)
359 {
360 	set_pmd(pmdp, __pmd(0));
361 }
362 
363 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
364 {
365 	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
366 }
367 
368 /* Find an entry in the third-level page table. */
369 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
370 
371 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))
372 #define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
373 
374 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
375 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
376 #define pte_unmap(pte)			do { } while (0)
377 #define pte_unmap_nested(pte)		do { } while (0)
378 
379 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
380 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
381 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
382 
383 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
384 
385 /* use ONLY for statically allocated translation tables */
386 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
387 
388 /*
389  * Conversion functions: convert a page and protection to a page entry,
390  * and a page entry and page directory to the page they refer to.
391  */
392 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
393 
394 #if CONFIG_PGTABLE_LEVELS > 2
395 
396 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
397 
398 #define pud_none(pud)		(!pud_val(pud))
399 #define pud_bad(pud)		(!(pud_val(pud) & 2))
400 #define pud_present(pud)	(pud_val(pud))
401 
402 static inline void set_pud(pud_t *pudp, pud_t pud)
403 {
404 	*pudp = pud;
405 	dsb(ishst);
406 	isb();
407 }
408 
409 static inline void pud_clear(pud_t *pudp)
410 {
411 	set_pud(pudp, __pud(0));
412 }
413 
414 static inline phys_addr_t pud_page_paddr(pud_t pud)
415 {
416 	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
417 }
418 
419 /* Find an entry in the second-level page table. */
420 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
421 
422 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
423 #define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
424 
425 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
426 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
427 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
428 
429 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
430 
431 /* use ONLY for statically allocated translation tables */
432 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
433 
434 #else
435 
436 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
437 
438 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
439 #define pmd_set_fixmap(addr)		NULL
440 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
441 #define pmd_clear_fixmap()
442 
443 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
444 
445 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
446 
447 #if CONFIG_PGTABLE_LEVELS > 3
448 
449 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
450 
451 #define pgd_none(pgd)		(!pgd_val(pgd))
452 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
453 #define pgd_present(pgd)	(pgd_val(pgd))
454 
455 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
456 {
457 	*pgdp = pgd;
458 	dsb(ishst);
459 }
460 
461 static inline void pgd_clear(pgd_t *pgdp)
462 {
463 	set_pgd(pgdp, __pgd(0));
464 }
465 
466 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
467 {
468 	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
469 }
470 
471 /* Find an entry in the frst-level page table. */
472 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
473 
474 #define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
475 #define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
476 
477 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
478 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
479 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
480 
481 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
482 
483 /* use ONLY for statically allocated translation tables */
484 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
485 
486 #else
487 
488 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
489 
490 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
491 #define pud_set_fixmap(addr)		NULL
492 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
493 #define pud_clear_fixmap()
494 
495 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
496 
497 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
498 
499 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
500 
501 /* to find an entry in a page-table-directory */
502 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
503 
504 #define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
505 
506 #define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
507 
508 /* to find an entry in a kernel page-table-directory */
509 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
510 
511 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
512 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
513 
514 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
515 {
516 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
517 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
518 	/* preserve the hardware dirty information */
519 	if (pte_hw_dirty(pte))
520 		pte = pte_mkdirty(pte);
521 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
522 	return pte;
523 }
524 
525 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
526 {
527 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
528 }
529 
530 #ifdef CONFIG_ARM64_HW_AFDBM
531 /*
532  * Atomic pte/pmd modifications.
533  */
534 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
535 static inline int __ptep_test_and_clear_young(pte_t *ptep)
536 {
537 	pteval_t pteval;
538 	unsigned int tmp, res;
539 
540 	asm volatile("//	__ptep_test_and_clear_young\n"
541 	"	prfm	pstl1strm, %2\n"
542 	"1:	ldxr	%0, %2\n"
543 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
544 	"	and	%0, %0, %4		// clear PTE_AF\n"
545 	"	stxr	%w1, %0, %2\n"
546 	"	cbnz	%w1, 1b\n"
547 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
548 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
549 
550 	return res;
551 }
552 
553 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
554 					    unsigned long address,
555 					    pte_t *ptep)
556 {
557 	return __ptep_test_and_clear_young(ptep);
558 }
559 
560 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
561 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
562 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
563 					    unsigned long address,
564 					    pmd_t *pmdp)
565 {
566 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
567 }
568 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
569 
570 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
571 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
572 				       unsigned long address, pte_t *ptep)
573 {
574 	pteval_t old_pteval;
575 	unsigned int tmp;
576 
577 	asm volatile("//	ptep_get_and_clear\n"
578 	"	prfm	pstl1strm, %2\n"
579 	"1:	ldxr	%0, %2\n"
580 	"	stxr	%w1, xzr, %2\n"
581 	"	cbnz	%w1, 1b\n"
582 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
583 
584 	return __pte(old_pteval);
585 }
586 
587 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
588 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
589 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
590 				       unsigned long address, pmd_t *pmdp)
591 {
592 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
593 }
594 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
595 
596 /*
597  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
598  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
599  */
600 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
601 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
602 {
603 	pteval_t pteval;
604 	unsigned long tmp;
605 
606 	asm volatile("//	ptep_set_wrprotect\n"
607 	"	prfm	pstl1strm, %2\n"
608 	"1:	ldxr	%0, %2\n"
609 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
610 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
611 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
612 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
613 	"	stxr	%w1, %0, %2\n"
614 	"	cbnz	%w1, 1b\n"
615 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
616 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
617 	: "cc");
618 }
619 
620 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
621 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
622 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
623 				      unsigned long address, pmd_t *pmdp)
624 {
625 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
626 }
627 #endif
628 #endif	/* CONFIG_ARM64_HW_AFDBM */
629 
630 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
631 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
632 
633 /*
634  * Encode and decode a swap entry:
635  *	bits 0-1:	present (must be zero)
636  *	bits 2-7:	swap type
637  *	bits 8-57:	swap offset
638  *	bit  58:	PTE_PROT_NONE (must be zero)
639  */
640 #define __SWP_TYPE_SHIFT	2
641 #define __SWP_TYPE_BITS		6
642 #define __SWP_OFFSET_BITS	50
643 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
644 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
645 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
646 
647 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
648 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
649 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
650 
651 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
652 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
653 
654 /*
655  * Ensure that there are not more swap files than can be encoded in the kernel
656  * PTEs.
657  */
658 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
659 
660 extern int kern_addr_valid(unsigned long addr);
661 
662 #include <asm-generic/pgtable.h>
663 
664 void pgd_cache_init(void);
665 #define pgtable_cache_init	pgd_cache_init
666 
667 /*
668  * On AArch64, the cache coherency is handled via the set_pte_at() function.
669  */
670 static inline void update_mmu_cache(struct vm_area_struct *vma,
671 				    unsigned long addr, pte_t *ptep)
672 {
673 	/*
674 	 * We don't do anything here, so there's a very small chance of
675 	 * us retaking a user fault which we just fixed up. The alternative
676 	 * is doing a dsb(ishst), but that penalises the fastpath.
677 	 */
678 }
679 
680 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
681 
682 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
683 #define kc_offset_to_vaddr(o)	((o) | VA_START)
684 
685 #endif /* !__ASSEMBLY__ */
686 
687 #endif /* __ASM_PGTABLE_H */
688