xref: /linux/arch/arm64/include/asm/pgtable.h (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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 range.
28  *
29  * VMALLOC_START: beginning of the kernel vmalloc space
30  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space
31  *	and fixed mappings
32  */
33 #define VMALLOC_START		(MODULES_END)
34 #define VMALLOC_END		(PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
35 
36 #define vmemmap			((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
37 
38 #define FIRST_USER_ADDRESS	0UL
39 
40 #ifndef __ASSEMBLY__
41 
42 #include <asm/fixmap.h>
43 #include <linux/mmdebug.h>
44 
45 extern void __pte_error(const char *file, int line, unsigned long val);
46 extern void __pmd_error(const char *file, int line, unsigned long val);
47 extern void __pud_error(const char *file, int line, unsigned long val);
48 extern void __pgd_error(const char *file, int line, unsigned long val);
49 
50 /*
51  * ZERO_PAGE is a global shared page that is always zero: used
52  * for zero-mapped memory areas etc..
53  */
54 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
55 #define ZERO_PAGE(vaddr)	pfn_to_page(PHYS_PFN(__pa(empty_zero_page)))
56 
57 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
58 
59 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
60 
61 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
62 
63 #define pte_none(pte)		(!pte_val(pte))
64 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
65 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
66 
67 /*
68  * The following only work if pte_present(). Undefined behaviour otherwise.
69  */
70 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
71 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
72 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
73 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
74 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
75 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
76 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
77 
78 #ifdef CONFIG_ARM64_HW_AFDBM
79 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
80 #else
81 #define pte_hw_dirty(pte)	(0)
82 #endif
83 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
84 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
85 
86 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
87 #define pte_valid_not_user(pte) \
88 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
89 #define pte_valid_young(pte) \
90 	((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
91 
92 /*
93  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
94  * so that we don't erroneously return false for pages that have been
95  * remapped as PROT_NONE but are yet to be flushed from the TLB.
96  */
97 #define pte_accessible(mm, pte)	\
98 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
99 
100 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
101 {
102 	pte_val(pte) &= ~pgprot_val(prot);
103 	return pte;
104 }
105 
106 static inline pte_t set_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 pte_wrprotect(pte_t pte)
113 {
114 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
115 }
116 
117 static inline pte_t pte_mkwrite(pte_t pte)
118 {
119 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
120 }
121 
122 static inline pte_t pte_mkclean(pte_t pte)
123 {
124 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
125 }
126 
127 static inline pte_t pte_mkdirty(pte_t pte)
128 {
129 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
130 }
131 
132 static inline pte_t pte_mkold(pte_t pte)
133 {
134 	return clear_pte_bit(pte, __pgprot(PTE_AF));
135 }
136 
137 static inline pte_t pte_mkyoung(pte_t pte)
138 {
139 	return set_pte_bit(pte, __pgprot(PTE_AF));
140 }
141 
142 static inline pte_t pte_mkspecial(pte_t pte)
143 {
144 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
145 }
146 
147 static inline pte_t pte_mkcont(pte_t pte)
148 {
149 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
150 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
151 }
152 
153 static inline pte_t pte_mknoncont(pte_t pte)
154 {
155 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
156 }
157 
158 static inline pmd_t pmd_mkcont(pmd_t pmd)
159 {
160 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
161 }
162 
163 static inline void set_pte(pte_t *ptep, pte_t pte)
164 {
165 	*ptep = pte;
166 
167 	/*
168 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
169 	 * or update_mmu_cache() have the necessary barriers.
170 	 */
171 	if (pte_valid_not_user(pte)) {
172 		dsb(ishst);
173 		isb();
174 	}
175 }
176 
177 struct mm_struct;
178 struct vm_area_struct;
179 
180 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
181 
182 /*
183  * PTE bits configuration in the presence of hardware Dirty Bit Management
184  * (PTE_WRITE == PTE_DBM):
185  *
186  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
187  *   0      0      |   1           0          0
188  *   0      1      |   1           1          0
189  *   1      0      |   1           0          1
190  *   1      1      |   0           1          x
191  *
192  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
193  * the page fault mechanism. Checking the dirty status of a pte becomes:
194  *
195  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
196  */
197 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
198 			      pte_t *ptep, pte_t pte)
199 {
200 	if (pte_present(pte)) {
201 		if (pte_sw_dirty(pte) && pte_write(pte))
202 			pte_val(pte) &= ~PTE_RDONLY;
203 		else
204 			pte_val(pte) |= PTE_RDONLY;
205 		if (pte_user(pte) && pte_exec(pte) && !pte_special(pte))
206 			__sync_icache_dcache(pte, addr);
207 	}
208 
209 	/*
210 	 * If the existing pte is valid, check for potential race with
211 	 * hardware updates of the pte (ptep_set_access_flags safely changes
212 	 * valid ptes without going through an invalid entry).
213 	 */
214 	if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
215 	    pte_valid(*ptep) && pte_valid(pte)) {
216 		VM_WARN_ONCE(!pte_young(pte),
217 			     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
218 			     __func__, pte_val(*ptep), pte_val(pte));
219 		VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
220 			     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
221 			     __func__, pte_val(*ptep), pte_val(pte));
222 	}
223 
224 	set_pte(ptep, pte);
225 }
226 
227 /*
228  * Huge pte definitions.
229  */
230 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
231 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
232 
233 /*
234  * Hugetlb definitions.
235  */
236 #define HUGE_MAX_HSTATE		4
237 #define HPAGE_SHIFT		PMD_SHIFT
238 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
239 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
240 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
241 
242 #define __HAVE_ARCH_PTE_SPECIAL
243 
244 static inline pte_t pud_pte(pud_t pud)
245 {
246 	return __pte(pud_val(pud));
247 }
248 
249 static inline pmd_t pud_pmd(pud_t pud)
250 {
251 	return __pmd(pud_val(pud));
252 }
253 
254 static inline pte_t pmd_pte(pmd_t pmd)
255 {
256 	return __pte(pmd_val(pmd));
257 }
258 
259 static inline pmd_t pte_pmd(pte_t pte)
260 {
261 	return __pmd(pte_val(pte));
262 }
263 
264 static inline pgprot_t mk_sect_prot(pgprot_t prot)
265 {
266 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
267 }
268 
269 #ifdef CONFIG_NUMA_BALANCING
270 /*
271  * See the comment in include/asm-generic/pgtable.h
272  */
273 static inline int pte_protnone(pte_t pte)
274 {
275 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
276 }
277 
278 static inline int pmd_protnone(pmd_t pmd)
279 {
280 	return pte_protnone(pmd_pte(pmd));
281 }
282 #endif
283 
284 /*
285  * THP definitions.
286  */
287 
288 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
289 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
290 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
291 
292 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
293 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
294 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
295 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
296 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
297 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
298 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
299 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
300 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
301 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
302 
303 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
304 
305 #define __HAVE_ARCH_PMD_WRITE
306 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
307 
308 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
309 
310 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
311 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
312 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
313 
314 #define pud_write(pud)		pte_write(pud_pte(pud))
315 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
316 
317 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
318 
319 #define __pgprot_modify(prot,mask,bits) \
320 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
321 
322 /*
323  * Mark the prot value as uncacheable and unbufferable.
324  */
325 #define pgprot_noncached(prot) \
326 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
327 #define pgprot_writecombine(prot) \
328 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
329 #define pgprot_device(prot) \
330 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
331 #define __HAVE_PHYS_MEM_ACCESS_PROT
332 struct file;
333 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
334 				     unsigned long size, pgprot_t vma_prot);
335 
336 #define pmd_none(pmd)		(!pmd_val(pmd))
337 
338 #define pmd_bad(pmd)		(!(pmd_val(pmd) & PMD_TABLE_BIT))
339 
340 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
341 				 PMD_TYPE_TABLE)
342 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
343 				 PMD_TYPE_SECT)
344 
345 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
346 #define pud_sect(pud)		(0)
347 #define pud_table(pud)		(1)
348 #else
349 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
350 				 PUD_TYPE_SECT)
351 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
352 				 PUD_TYPE_TABLE)
353 #endif
354 
355 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
356 {
357 	*pmdp = pmd;
358 	dsb(ishst);
359 	isb();
360 }
361 
362 static inline void pmd_clear(pmd_t *pmdp)
363 {
364 	set_pmd(pmdp, __pmd(0));
365 }
366 
367 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
368 {
369 	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
370 }
371 
372 /* Find an entry in the third-level page table. */
373 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
374 
375 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))
376 #define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
377 
378 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
379 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
380 #define pte_unmap(pte)			do { } while (0)
381 #define pte_unmap_nested(pte)		do { } while (0)
382 
383 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
384 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
385 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
386 
387 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
388 
389 /* use ONLY for statically allocated translation tables */
390 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
391 
392 /*
393  * Conversion functions: convert a page and protection to a page entry,
394  * and a page entry and page directory to the page they refer to.
395  */
396 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
397 
398 #if CONFIG_PGTABLE_LEVELS > 2
399 
400 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
401 
402 #define pud_none(pud)		(!pud_val(pud))
403 #define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
404 #define pud_present(pud)	(pud_val(pud))
405 
406 static inline void set_pud(pud_t *pudp, pud_t pud)
407 {
408 	*pudp = pud;
409 	dsb(ishst);
410 	isb();
411 }
412 
413 static inline void pud_clear(pud_t *pudp)
414 {
415 	set_pud(pudp, __pud(0));
416 }
417 
418 static inline phys_addr_t pud_page_paddr(pud_t pud)
419 {
420 	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
421 }
422 
423 /* Find an entry in the second-level page table. */
424 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
425 
426 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
427 #define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
428 
429 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
430 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
431 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
432 
433 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
434 
435 /* use ONLY for statically allocated translation tables */
436 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
437 
438 #else
439 
440 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
441 
442 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
443 #define pmd_set_fixmap(addr)		NULL
444 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
445 #define pmd_clear_fixmap()
446 
447 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
448 
449 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
450 
451 #if CONFIG_PGTABLE_LEVELS > 3
452 
453 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
454 
455 #define pgd_none(pgd)		(!pgd_val(pgd))
456 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
457 #define pgd_present(pgd)	(pgd_val(pgd))
458 
459 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
460 {
461 	*pgdp = pgd;
462 	dsb(ishst);
463 }
464 
465 static inline void pgd_clear(pgd_t *pgdp)
466 {
467 	set_pgd(pgdp, __pgd(0));
468 }
469 
470 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
471 {
472 	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
473 }
474 
475 /* Find an entry in the frst-level page table. */
476 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
477 
478 #define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
479 #define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
480 
481 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
482 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
483 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
484 
485 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
486 
487 /* use ONLY for statically allocated translation tables */
488 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
489 
490 #else
491 
492 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
493 
494 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
495 #define pud_set_fixmap(addr)		NULL
496 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
497 #define pud_clear_fixmap()
498 
499 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
500 
501 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
502 
503 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
504 
505 /* to find an entry in a page-table-directory */
506 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
507 
508 #define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
509 
510 #define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
511 
512 /* to find an entry in a kernel page-table-directory */
513 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
514 
515 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
516 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
517 
518 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
519 {
520 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
521 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
522 	/* preserve the hardware dirty information */
523 	if (pte_hw_dirty(pte))
524 		pte = pte_mkdirty(pte);
525 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
526 	return pte;
527 }
528 
529 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
530 {
531 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
532 }
533 
534 #ifdef CONFIG_ARM64_HW_AFDBM
535 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
536 extern int ptep_set_access_flags(struct vm_area_struct *vma,
537 				 unsigned long address, pte_t *ptep,
538 				 pte_t entry, int dirty);
539 
540 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
541 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
542 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
543 					unsigned long address, pmd_t *pmdp,
544 					pmd_t entry, int dirty)
545 {
546 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
547 }
548 #endif
549 
550 /*
551  * Atomic pte/pmd modifications.
552  */
553 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
554 static inline int __ptep_test_and_clear_young(pte_t *ptep)
555 {
556 	pteval_t pteval;
557 	unsigned int tmp, res;
558 
559 	asm volatile("//	__ptep_test_and_clear_young\n"
560 	"	prfm	pstl1strm, %2\n"
561 	"1:	ldxr	%0, %2\n"
562 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
563 	"	and	%0, %0, %4		// clear PTE_AF\n"
564 	"	stxr	%w1, %0, %2\n"
565 	"	cbnz	%w1, 1b\n"
566 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
567 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
568 
569 	return res;
570 }
571 
572 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
573 					    unsigned long address,
574 					    pte_t *ptep)
575 {
576 	return __ptep_test_and_clear_young(ptep);
577 }
578 
579 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
580 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
581 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
582 					    unsigned long address,
583 					    pmd_t *pmdp)
584 {
585 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
586 }
587 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
588 
589 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
590 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
591 				       unsigned long address, pte_t *ptep)
592 {
593 	pteval_t old_pteval;
594 	unsigned int tmp;
595 
596 	asm volatile("//	ptep_get_and_clear\n"
597 	"	prfm	pstl1strm, %2\n"
598 	"1:	ldxr	%0, %2\n"
599 	"	stxr	%w1, xzr, %2\n"
600 	"	cbnz	%w1, 1b\n"
601 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
602 
603 	return __pte(old_pteval);
604 }
605 
606 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
607 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
608 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
609 					    unsigned long address, pmd_t *pmdp)
610 {
611 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
612 }
613 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
614 
615 /*
616  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
617  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
618  */
619 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
620 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
621 {
622 	pteval_t pteval;
623 	unsigned long tmp;
624 
625 	asm volatile("//	ptep_set_wrprotect\n"
626 	"	prfm	pstl1strm, %2\n"
627 	"1:	ldxr	%0, %2\n"
628 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
629 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
630 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
631 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
632 	"	stxr	%w1, %0, %2\n"
633 	"	cbnz	%w1, 1b\n"
634 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
635 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
636 	: "cc");
637 }
638 
639 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
640 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
641 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
642 				      unsigned long address, pmd_t *pmdp)
643 {
644 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
645 }
646 #endif
647 #endif	/* CONFIG_ARM64_HW_AFDBM */
648 
649 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
650 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
651 
652 /*
653  * Encode and decode a swap entry:
654  *	bits 0-1:	present (must be zero)
655  *	bits 2-7:	swap type
656  *	bits 8-57:	swap offset
657  *	bit  58:	PTE_PROT_NONE (must be zero)
658  */
659 #define __SWP_TYPE_SHIFT	2
660 #define __SWP_TYPE_BITS		6
661 #define __SWP_OFFSET_BITS	50
662 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
663 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
664 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
665 
666 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
667 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
668 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
669 
670 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
671 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
672 
673 /*
674  * Ensure that there are not more swap files than can be encoded in the kernel
675  * PTEs.
676  */
677 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
678 
679 extern int kern_addr_valid(unsigned long addr);
680 
681 #include <asm-generic/pgtable.h>
682 
683 void pgd_cache_init(void);
684 #define pgtable_cache_init	pgd_cache_init
685 
686 /*
687  * On AArch64, the cache coherency is handled via the set_pte_at() function.
688  */
689 static inline void update_mmu_cache(struct vm_area_struct *vma,
690 				    unsigned long addr, pte_t *ptep)
691 {
692 	/*
693 	 * We don't do anything here, so there's a very small chance of
694 	 * us retaking a user fault which we just fixed up. The alternative
695 	 * is doing a dsb(ishst), but that penalises the fastpath.
696 	 */
697 }
698 
699 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
700 
701 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
702 #define kc_offset_to_vaddr(o)	((o) | VA_START)
703 
704 #endif /* !__ASSEMBLY__ */
705 
706 #endif /* __ASM_PGTABLE_H */
707