xref: /openbmc/linux/arch/arm64/include/asm/pgtable.h (revision e983940270f10fe8551baf0098be76ea478294a3)
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_ng(pte)		(!!(pte_val(pte) & PTE_NG))
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_global(pte) \
88 	((pte_val(pte) & (PTE_VALID | PTE_NG)) == 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 pte_t pte_clear_rdonly(pte_t pte)
159 {
160 	return clear_pte_bit(pte, __pgprot(PTE_RDONLY));
161 }
162 
163 static inline pte_t pte_mkpresent(pte_t pte)
164 {
165 	return set_pte_bit(pte, __pgprot(PTE_VALID));
166 }
167 
168 static inline pmd_t pmd_mkcont(pmd_t pmd)
169 {
170 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
171 }
172 
173 static inline void set_pte(pte_t *ptep, pte_t pte)
174 {
175 	*ptep = pte;
176 
177 	/*
178 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
179 	 * or update_mmu_cache() have the necessary barriers.
180 	 */
181 	if (pte_valid_global(pte)) {
182 		dsb(ishst);
183 		isb();
184 	}
185 }
186 
187 struct mm_struct;
188 struct vm_area_struct;
189 
190 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
191 
192 /*
193  * PTE bits configuration in the presence of hardware Dirty Bit Management
194  * (PTE_WRITE == PTE_DBM):
195  *
196  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
197  *   0      0      |   1           0          0
198  *   0      1      |   1           1          0
199  *   1      0      |   1           0          1
200  *   1      1      |   0           1          x
201  *
202  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
203  * the page fault mechanism. Checking the dirty status of a pte becomes:
204  *
205  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
206  */
207 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
208 			      pte_t *ptep, pte_t pte)
209 {
210 	if (pte_present(pte)) {
211 		if (pte_sw_dirty(pte) && pte_write(pte))
212 			pte_val(pte) &= ~PTE_RDONLY;
213 		else
214 			pte_val(pte) |= PTE_RDONLY;
215 		if (pte_ng(pte) && pte_exec(pte) && !pte_special(pte))
216 			__sync_icache_dcache(pte, addr);
217 	}
218 
219 	/*
220 	 * If the existing pte is valid, check for potential race with
221 	 * hardware updates of the pte (ptep_set_access_flags safely changes
222 	 * valid ptes without going through an invalid entry).
223 	 */
224 	if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
225 	    pte_valid(*ptep) && pte_valid(pte)) {
226 		VM_WARN_ONCE(!pte_young(pte),
227 			     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
228 			     __func__, pte_val(*ptep), pte_val(pte));
229 		VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
230 			     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
231 			     __func__, pte_val(*ptep), pte_val(pte));
232 	}
233 
234 	set_pte(ptep, pte);
235 }
236 
237 #define __HAVE_ARCH_PTE_SAME
238 static inline int pte_same(pte_t pte_a, pte_t pte_b)
239 {
240 	pteval_t lhs, rhs;
241 
242 	lhs = pte_val(pte_a);
243 	rhs = pte_val(pte_b);
244 
245 	if (pte_present(pte_a))
246 		lhs &= ~PTE_RDONLY;
247 
248 	if (pte_present(pte_b))
249 		rhs &= ~PTE_RDONLY;
250 
251 	return (lhs == rhs);
252 }
253 
254 /*
255  * Huge pte definitions.
256  */
257 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
258 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
259 
260 /*
261  * Hugetlb definitions.
262  */
263 #define HUGE_MAX_HSTATE		4
264 #define HPAGE_SHIFT		PMD_SHIFT
265 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
266 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
267 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
268 
269 #define __HAVE_ARCH_PTE_SPECIAL
270 
271 static inline pte_t pud_pte(pud_t pud)
272 {
273 	return __pte(pud_val(pud));
274 }
275 
276 static inline pmd_t pud_pmd(pud_t pud)
277 {
278 	return __pmd(pud_val(pud));
279 }
280 
281 static inline pte_t pmd_pte(pmd_t pmd)
282 {
283 	return __pte(pmd_val(pmd));
284 }
285 
286 static inline pmd_t pte_pmd(pte_t pte)
287 {
288 	return __pmd(pte_val(pte));
289 }
290 
291 static inline pgprot_t mk_sect_prot(pgprot_t prot)
292 {
293 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
294 }
295 
296 #ifdef CONFIG_NUMA_BALANCING
297 /*
298  * See the comment in include/asm-generic/pgtable.h
299  */
300 static inline int pte_protnone(pte_t pte)
301 {
302 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
303 }
304 
305 static inline int pmd_protnone(pmd_t pmd)
306 {
307 	return pte_protnone(pmd_pte(pmd));
308 }
309 #endif
310 
311 /*
312  * THP definitions.
313  */
314 
315 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
316 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
317 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
318 
319 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
320 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
321 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
322 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
323 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
324 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
325 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
326 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
327 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
328 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
329 
330 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
331 
332 #define __HAVE_ARCH_PMD_WRITE
333 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
334 
335 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
336 
337 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
338 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
339 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
340 
341 #define pud_write(pud)		pte_write(pud_pte(pud))
342 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
343 
344 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
345 
346 #define __pgprot_modify(prot,mask,bits) \
347 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
348 
349 /*
350  * Mark the prot value as uncacheable and unbufferable.
351  */
352 #define pgprot_noncached(prot) \
353 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
354 #define pgprot_writecombine(prot) \
355 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
356 #define pgprot_device(prot) \
357 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
358 #define __HAVE_PHYS_MEM_ACCESS_PROT
359 struct file;
360 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
361 				     unsigned long size, pgprot_t vma_prot);
362 
363 #define pmd_none(pmd)		(!pmd_val(pmd))
364 
365 #define pmd_bad(pmd)		(!(pmd_val(pmd) & PMD_TABLE_BIT))
366 
367 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
368 				 PMD_TYPE_TABLE)
369 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
370 				 PMD_TYPE_SECT)
371 
372 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
373 #define pud_sect(pud)		(0)
374 #define pud_table(pud)		(1)
375 #else
376 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
377 				 PUD_TYPE_SECT)
378 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
379 				 PUD_TYPE_TABLE)
380 #endif
381 
382 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
383 {
384 	*pmdp = pmd;
385 	dsb(ishst);
386 	isb();
387 }
388 
389 static inline void pmd_clear(pmd_t *pmdp)
390 {
391 	set_pmd(pmdp, __pmd(0));
392 }
393 
394 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
395 {
396 	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
397 }
398 
399 /* Find an entry in the third-level page table. */
400 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
401 
402 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))
403 #define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
404 
405 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
406 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
407 #define pte_unmap(pte)			do { } while (0)
408 #define pte_unmap_nested(pte)		do { } while (0)
409 
410 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
411 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
412 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
413 
414 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
415 
416 /* use ONLY for statically allocated translation tables */
417 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
418 
419 /*
420  * Conversion functions: convert a page and protection to a page entry,
421  * and a page entry and page directory to the page they refer to.
422  */
423 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
424 
425 #if CONFIG_PGTABLE_LEVELS > 2
426 
427 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
428 
429 #define pud_none(pud)		(!pud_val(pud))
430 #define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
431 #define pud_present(pud)	(pud_val(pud))
432 
433 static inline void set_pud(pud_t *pudp, pud_t pud)
434 {
435 	*pudp = pud;
436 	dsb(ishst);
437 	isb();
438 }
439 
440 static inline void pud_clear(pud_t *pudp)
441 {
442 	set_pud(pudp, __pud(0));
443 }
444 
445 static inline phys_addr_t pud_page_paddr(pud_t pud)
446 {
447 	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
448 }
449 
450 /* Find an entry in the second-level page table. */
451 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
452 
453 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
454 #define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
455 
456 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
457 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
458 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
459 
460 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
461 
462 /* use ONLY for statically allocated translation tables */
463 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
464 
465 #else
466 
467 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
468 
469 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
470 #define pmd_set_fixmap(addr)		NULL
471 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
472 #define pmd_clear_fixmap()
473 
474 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
475 
476 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
477 
478 #if CONFIG_PGTABLE_LEVELS > 3
479 
480 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
481 
482 #define pgd_none(pgd)		(!pgd_val(pgd))
483 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
484 #define pgd_present(pgd)	(pgd_val(pgd))
485 
486 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
487 {
488 	*pgdp = pgd;
489 	dsb(ishst);
490 }
491 
492 static inline void pgd_clear(pgd_t *pgdp)
493 {
494 	set_pgd(pgdp, __pgd(0));
495 }
496 
497 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
498 {
499 	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
500 }
501 
502 /* Find an entry in the frst-level page table. */
503 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
504 
505 #define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
506 #define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
507 
508 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
509 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
510 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
511 
512 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
513 
514 /* use ONLY for statically allocated translation tables */
515 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
516 
517 #else
518 
519 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
520 
521 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
522 #define pud_set_fixmap(addr)		NULL
523 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
524 #define pud_clear_fixmap()
525 
526 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
527 
528 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
529 
530 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
531 
532 /* to find an entry in a page-table-directory */
533 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
534 
535 #define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
536 
537 #define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
538 
539 /* to find an entry in a kernel page-table-directory */
540 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
541 
542 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
543 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
544 
545 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
546 {
547 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
548 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
549 	/* preserve the hardware dirty information */
550 	if (pte_hw_dirty(pte))
551 		pte = pte_mkdirty(pte);
552 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
553 	return pte;
554 }
555 
556 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
557 {
558 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
559 }
560 
561 #ifdef CONFIG_ARM64_HW_AFDBM
562 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
563 extern int ptep_set_access_flags(struct vm_area_struct *vma,
564 				 unsigned long address, pte_t *ptep,
565 				 pte_t entry, int dirty);
566 
567 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
568 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
569 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
570 					unsigned long address, pmd_t *pmdp,
571 					pmd_t entry, int dirty)
572 {
573 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
574 }
575 #endif
576 
577 /*
578  * Atomic pte/pmd modifications.
579  */
580 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
581 static inline int __ptep_test_and_clear_young(pte_t *ptep)
582 {
583 	pteval_t pteval;
584 	unsigned int tmp, res;
585 
586 	asm volatile("//	__ptep_test_and_clear_young\n"
587 	"	prfm	pstl1strm, %2\n"
588 	"1:	ldxr	%0, %2\n"
589 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
590 	"	and	%0, %0, %4		// clear PTE_AF\n"
591 	"	stxr	%w1, %0, %2\n"
592 	"	cbnz	%w1, 1b\n"
593 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
594 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
595 
596 	return res;
597 }
598 
599 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
600 					    unsigned long address,
601 					    pte_t *ptep)
602 {
603 	return __ptep_test_and_clear_young(ptep);
604 }
605 
606 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
607 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
608 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
609 					    unsigned long address,
610 					    pmd_t *pmdp)
611 {
612 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
613 }
614 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
615 
616 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
617 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
618 				       unsigned long address, pte_t *ptep)
619 {
620 	pteval_t old_pteval;
621 	unsigned int tmp;
622 
623 	asm volatile("//	ptep_get_and_clear\n"
624 	"	prfm	pstl1strm, %2\n"
625 	"1:	ldxr	%0, %2\n"
626 	"	stxr	%w1, xzr, %2\n"
627 	"	cbnz	%w1, 1b\n"
628 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
629 
630 	return __pte(old_pteval);
631 }
632 
633 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
634 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
635 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
636 					    unsigned long address, pmd_t *pmdp)
637 {
638 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
639 }
640 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
641 
642 /*
643  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
644  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
645  */
646 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
647 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
648 {
649 	pteval_t pteval;
650 	unsigned long tmp;
651 
652 	asm volatile("//	ptep_set_wrprotect\n"
653 	"	prfm	pstl1strm, %2\n"
654 	"1:	ldxr	%0, %2\n"
655 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
656 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
657 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
658 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
659 	"	stxr	%w1, %0, %2\n"
660 	"	cbnz	%w1, 1b\n"
661 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
662 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
663 	: "cc");
664 }
665 
666 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
667 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
668 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
669 				      unsigned long address, pmd_t *pmdp)
670 {
671 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
672 }
673 #endif
674 #endif	/* CONFIG_ARM64_HW_AFDBM */
675 
676 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
677 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
678 
679 /*
680  * Encode and decode a swap entry:
681  *	bits 0-1:	present (must be zero)
682  *	bits 2-7:	swap type
683  *	bits 8-57:	swap offset
684  *	bit  58:	PTE_PROT_NONE (must be zero)
685  */
686 #define __SWP_TYPE_SHIFT	2
687 #define __SWP_TYPE_BITS		6
688 #define __SWP_OFFSET_BITS	50
689 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
690 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
691 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
692 
693 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
694 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
695 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
696 
697 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
698 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
699 
700 /*
701  * Ensure that there are not more swap files than can be encoded in the kernel
702  * PTEs.
703  */
704 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
705 
706 extern int kern_addr_valid(unsigned long addr);
707 
708 #include <asm-generic/pgtable.h>
709 
710 void pgd_cache_init(void);
711 #define pgtable_cache_init	pgd_cache_init
712 
713 /*
714  * On AArch64, the cache coherency is handled via the set_pte_at() function.
715  */
716 static inline void update_mmu_cache(struct vm_area_struct *vma,
717 				    unsigned long addr, pte_t *ptep)
718 {
719 	/*
720 	 * We don't do anything here, so there's a very small chance of
721 	 * us retaking a user fault which we just fixed up. The alternative
722 	 * is doing a dsb(ishst), but that penalises the fastpath.
723 	 */
724 }
725 
726 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
727 
728 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
729 #define kc_offset_to_vaddr(o)	((o) | VA_START)
730 
731 #endif /* !__ASSEMBLY__ */
732 
733 #endif /* __ASM_PGTABLE_H */
734