xref: /linux/arch/arm64/include/asm/pgtable.h (revision 4ddd32741da87657113d964588ce13ee64b34820)
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 
25 /*
26  * Software defined PTE bits definition.
27  */
28 #define PTE_VALID		(_AT(pteval_t, 1) << 0)
29 #define PTE_WRITE		(PTE_DBM)		 /* same as DBM (51) */
30 #define PTE_DIRTY		(_AT(pteval_t, 1) << 55)
31 #define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)
32 #define PTE_PROT_NONE		(_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
33 
34 /*
35  * VMALLOC and SPARSEMEM_VMEMMAP ranges.
36  *
37  * VMEMAP_SIZE: allows the whole VA space to be covered by a struct page array
38  *	(rounded up to PUD_SIZE).
39  * VMALLOC_START: beginning of the kernel VA space
40  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
41  *	fixed mappings and modules
42  */
43 #define VMEMMAP_SIZE		ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
44 #define VMALLOC_START		(UL(0xffffffffffffffff) << VA_BITS)
45 #define VMALLOC_END		(PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
46 
47 #define vmemmap			((struct page *)(VMALLOC_END + SZ_64K))
48 
49 #define FIRST_USER_ADDRESS	0UL
50 
51 #ifndef __ASSEMBLY__
52 
53 #include <linux/mmdebug.h>
54 
55 extern void __pte_error(const char *file, int line, unsigned long val);
56 extern void __pmd_error(const char *file, int line, unsigned long val);
57 extern void __pud_error(const char *file, int line, unsigned long val);
58 extern void __pgd_error(const char *file, int line, unsigned long val);
59 
60 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
61 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
62 
63 #define PROT_DEVICE_nGnRnE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
64 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
65 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
66 #define PROT_NORMAL_WT		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_WT))
67 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
68 
69 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
70 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
71 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
72 
73 #define _PAGE_DEFAULT		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
74 
75 #define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
76 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
77 
78 #define PAGE_HYP		__pgprot(_PAGE_DEFAULT | PTE_HYP)
79 #define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
80 
81 #define PAGE_S2			__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
82 #define PAGE_S2_DEVICE		__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
83 
84 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
85 #define PAGE_SHARED		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
86 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
87 #define PAGE_COPY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
88 #define PAGE_COPY_EXEC		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
89 #define PAGE_READONLY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
90 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
91 
92 #define __P000  PAGE_NONE
93 #define __P001  PAGE_READONLY
94 #define __P010  PAGE_COPY
95 #define __P011  PAGE_COPY
96 #define __P100  PAGE_READONLY_EXEC
97 #define __P101  PAGE_READONLY_EXEC
98 #define __P110  PAGE_COPY_EXEC
99 #define __P111  PAGE_COPY_EXEC
100 
101 #define __S000  PAGE_NONE
102 #define __S001  PAGE_READONLY
103 #define __S010  PAGE_SHARED
104 #define __S011  PAGE_SHARED
105 #define __S100  PAGE_READONLY_EXEC
106 #define __S101  PAGE_READONLY_EXEC
107 #define __S110  PAGE_SHARED_EXEC
108 #define __S111  PAGE_SHARED_EXEC
109 
110 /*
111  * ZERO_PAGE is a global shared page that is always zero: used
112  * for zero-mapped memory areas etc..
113  */
114 extern struct page *empty_zero_page;
115 #define ZERO_PAGE(vaddr)	(empty_zero_page)
116 
117 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
118 
119 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
120 
121 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
122 
123 #define pte_none(pte)		(!pte_val(pte))
124 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
125 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
126 
127 /* Find an entry in the third-level page table. */
128 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
129 
130 #define pte_offset_kernel(dir,addr)	(pmd_page_vaddr(*(dir)) + pte_index(addr))
131 
132 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
133 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
134 #define pte_unmap(pte)			do { } while (0)
135 #define pte_unmap_nested(pte)		do { } while (0)
136 
137 /*
138  * The following only work if pte_present(). Undefined behaviour otherwise.
139  */
140 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
141 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
142 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
143 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
144 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
145 
146 #ifdef CONFIG_ARM64_HW_AFDBM
147 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
148 #else
149 #define pte_hw_dirty(pte)	(0)
150 #endif
151 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
152 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
153 
154 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
155 #define pte_valid_user(pte) \
156 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
157 #define pte_valid_not_user(pte) \
158 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
159 
160 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
161 {
162 	pte_val(pte) &= ~pgprot_val(prot);
163 	return pte;
164 }
165 
166 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
167 {
168 	pte_val(pte) |= pgprot_val(prot);
169 	return pte;
170 }
171 
172 static inline pte_t pte_wrprotect(pte_t pte)
173 {
174 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
175 }
176 
177 static inline pte_t pte_mkwrite(pte_t pte)
178 {
179 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
180 }
181 
182 static inline pte_t pte_mkclean(pte_t pte)
183 {
184 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
185 }
186 
187 static inline pte_t pte_mkdirty(pte_t pte)
188 {
189 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
190 }
191 
192 static inline pte_t pte_mkold(pte_t pte)
193 {
194 	return clear_pte_bit(pte, __pgprot(PTE_AF));
195 }
196 
197 static inline pte_t pte_mkyoung(pte_t pte)
198 {
199 	return set_pte_bit(pte, __pgprot(PTE_AF));
200 }
201 
202 static inline pte_t pte_mkspecial(pte_t pte)
203 {
204 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
205 }
206 
207 static inline void set_pte(pte_t *ptep, pte_t pte)
208 {
209 	*ptep = pte;
210 
211 	/*
212 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
213 	 * or update_mmu_cache() have the necessary barriers.
214 	 */
215 	if (pte_valid_not_user(pte)) {
216 		dsb(ishst);
217 		isb();
218 	}
219 }
220 
221 struct mm_struct;
222 struct vm_area_struct;
223 
224 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
225 
226 /*
227  * PTE bits configuration in the presence of hardware Dirty Bit Management
228  * (PTE_WRITE == PTE_DBM):
229  *
230  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
231  *   0      0      |   1           0          0
232  *   0      1      |   1           1          0
233  *   1      0      |   1           0          1
234  *   1      1      |   0           1          x
235  *
236  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
237  * the page fault mechanism. Checking the dirty status of a pte becomes:
238  *
239  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
240  */
241 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
242 			      pte_t *ptep, pte_t pte)
243 {
244 	if (pte_valid_user(pte)) {
245 		if (!pte_special(pte) && pte_exec(pte))
246 			__sync_icache_dcache(pte, addr);
247 		if (pte_sw_dirty(pte) && pte_write(pte))
248 			pte_val(pte) &= ~PTE_RDONLY;
249 		else
250 			pte_val(pte) |= PTE_RDONLY;
251 	}
252 
253 	/*
254 	 * If the existing pte is valid, check for potential race with
255 	 * hardware updates of the pte (ptep_set_access_flags safely changes
256 	 * valid ptes without going through an invalid entry).
257 	 */
258 	if (IS_ENABLED(CONFIG_DEBUG_VM) && IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
259 	    pte_valid(*ptep)) {
260 		BUG_ON(!pte_young(pte));
261 		BUG_ON(pte_write(*ptep) && !pte_dirty(pte));
262 	}
263 
264 	set_pte(ptep, pte);
265 }
266 
267 /*
268  * Huge pte definitions.
269  */
270 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
271 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
272 
273 /*
274  * Hugetlb definitions.
275  */
276 #define HUGE_MAX_HSTATE		2
277 #define HPAGE_SHIFT		PMD_SHIFT
278 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
279 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
280 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
281 
282 #define __HAVE_ARCH_PTE_SPECIAL
283 
284 static inline pte_t pud_pte(pud_t pud)
285 {
286 	return __pte(pud_val(pud));
287 }
288 
289 static inline pmd_t pud_pmd(pud_t pud)
290 {
291 	return __pmd(pud_val(pud));
292 }
293 
294 static inline pte_t pmd_pte(pmd_t pmd)
295 {
296 	return __pte(pmd_val(pmd));
297 }
298 
299 static inline pmd_t pte_pmd(pte_t pte)
300 {
301 	return __pmd(pte_val(pte));
302 }
303 
304 static inline pgprot_t mk_sect_prot(pgprot_t prot)
305 {
306 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
307 }
308 
309 /*
310  * THP definitions.
311  */
312 
313 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
314 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
315 #define pmd_trans_splitting(pmd)	pte_special(pmd_pte(pmd))
316 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
317 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
318 struct vm_area_struct;
319 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
320 			  pmd_t *pmdp);
321 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
322 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
323 
324 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
325 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
326 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
327 #define pmd_mksplitting(pmd)	pte_pmd(pte_mkspecial(pmd_pte(pmd)))
328 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
329 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
330 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
331 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
332 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
333 
334 #define __HAVE_ARCH_PMD_WRITE
335 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
336 
337 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
338 
339 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
340 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
341 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
342 
343 #define pud_write(pud)		pte_write(pud_pte(pud))
344 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
345 
346 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
347 
348 static inline int has_transparent_hugepage(void)
349 {
350 	return 1;
351 }
352 
353 #define __pgprot_modify(prot,mask,bits) \
354 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
355 
356 /*
357  * Mark the prot value as uncacheable and unbufferable.
358  */
359 #define pgprot_noncached(prot) \
360 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
361 #define pgprot_writecombine(prot) \
362 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
363 #define pgprot_device(prot) \
364 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
365 #define __HAVE_PHYS_MEM_ACCESS_PROT
366 struct file;
367 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
368 				     unsigned long size, pgprot_t vma_prot);
369 
370 #define pmd_none(pmd)		(!pmd_val(pmd))
371 #define pmd_present(pmd)	(pmd_val(pmd))
372 
373 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
374 
375 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
376 				 PMD_TYPE_TABLE)
377 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
378 				 PMD_TYPE_SECT)
379 
380 #ifdef CONFIG_ARM64_64K_PAGES
381 #define pud_sect(pud)		(0)
382 #define pud_table(pud)		(1)
383 #else
384 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
385 				 PUD_TYPE_SECT)
386 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
387 				 PUD_TYPE_TABLE)
388 #endif
389 
390 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
391 {
392 	*pmdp = pmd;
393 	dsb(ishst);
394 	isb();
395 }
396 
397 static inline void pmd_clear(pmd_t *pmdp)
398 {
399 	set_pmd(pmdp, __pmd(0));
400 }
401 
402 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
403 {
404 	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
405 }
406 
407 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
408 
409 /*
410  * Conversion functions: convert a page and protection to a page entry,
411  * and a page entry and page directory to the page they refer to.
412  */
413 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
414 
415 #if CONFIG_PGTABLE_LEVELS > 2
416 
417 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
418 
419 #define pud_none(pud)		(!pud_val(pud))
420 #define pud_bad(pud)		(!(pud_val(pud) & 2))
421 #define pud_present(pud)	(pud_val(pud))
422 
423 static inline void set_pud(pud_t *pudp, pud_t pud)
424 {
425 	*pudp = pud;
426 	dsb(ishst);
427 	isb();
428 }
429 
430 static inline void pud_clear(pud_t *pudp)
431 {
432 	set_pud(pudp, __pud(0));
433 }
434 
435 static inline pmd_t *pud_page_vaddr(pud_t pud)
436 {
437 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
438 }
439 
440 /* Find an entry in the second-level page table. */
441 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
442 
443 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
444 {
445 	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
446 }
447 
448 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
449 
450 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
451 
452 #if CONFIG_PGTABLE_LEVELS > 3
453 
454 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
455 
456 #define pgd_none(pgd)		(!pgd_val(pgd))
457 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
458 #define pgd_present(pgd)	(pgd_val(pgd))
459 
460 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
461 {
462 	*pgdp = pgd;
463 	dsb(ishst);
464 }
465 
466 static inline void pgd_clear(pgd_t *pgdp)
467 {
468 	set_pgd(pgdp, __pgd(0));
469 }
470 
471 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
472 {
473 	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
474 }
475 
476 /* Find an entry in the frst-level page table. */
477 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
478 
479 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
480 {
481 	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
482 }
483 
484 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
485 
486 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
487 
488 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
489 
490 /* to find an entry in a page-table-directory */
491 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
492 
493 #define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))
494 
495 /* to find an entry in a kernel page-table-directory */
496 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
497 
498 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
499 {
500 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
501 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
502 	/* preserve the hardware dirty information */
503 	if (pte_hw_dirty(pte))
504 		pte = pte_mkdirty(pte);
505 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
506 	return pte;
507 }
508 
509 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
510 {
511 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
512 }
513 
514 #ifdef CONFIG_ARM64_HW_AFDBM
515 /*
516  * Atomic pte/pmd modifications.
517  */
518 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
519 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
520 					    unsigned long address,
521 					    pte_t *ptep)
522 {
523 	pteval_t pteval;
524 	unsigned int tmp, res;
525 
526 	asm volatile("//	ptep_test_and_clear_young\n"
527 	"	prfm	pstl1strm, %2\n"
528 	"1:	ldxr	%0, %2\n"
529 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
530 	"	and	%0, %0, %4		// clear PTE_AF\n"
531 	"	stxr	%w1, %0, %2\n"
532 	"	cbnz	%w1, 1b\n"
533 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
534 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
535 
536 	return res;
537 }
538 
539 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
540 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
541 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
542 					    unsigned long address,
543 					    pmd_t *pmdp)
544 {
545 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
546 }
547 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
548 
549 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
550 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
551 				       unsigned long address, pte_t *ptep)
552 {
553 	pteval_t old_pteval;
554 	unsigned int tmp;
555 
556 	asm volatile("//	ptep_get_and_clear\n"
557 	"	prfm	pstl1strm, %2\n"
558 	"1:	ldxr	%0, %2\n"
559 	"	stxr	%w1, xzr, %2\n"
560 	"	cbnz	%w1, 1b\n"
561 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
562 
563 	return __pte(old_pteval);
564 }
565 
566 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
567 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
568 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
569 				       unsigned long address, pmd_t *pmdp)
570 {
571 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
572 }
573 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
574 
575 /*
576  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
577  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
578  */
579 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
580 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
581 {
582 	pteval_t pteval;
583 	unsigned long tmp;
584 
585 	asm volatile("//	ptep_set_wrprotect\n"
586 	"	prfm	pstl1strm, %2\n"
587 	"1:	ldxr	%0, %2\n"
588 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
589 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
590 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
591 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
592 	"	stxr	%w1, %0, %2\n"
593 	"	cbnz	%w1, 1b\n"
594 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
595 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
596 	: "cc");
597 }
598 
599 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
600 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
601 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
602 				      unsigned long address, pmd_t *pmdp)
603 {
604 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
605 }
606 #endif
607 #endif	/* CONFIG_ARM64_HW_AFDBM */
608 
609 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
610 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
611 
612 /*
613  * Encode and decode a swap entry:
614  *	bits 0-1:	present (must be zero)
615  *	bits 2-7:	swap type
616  *	bits 8-57:	swap offset
617  */
618 #define __SWP_TYPE_SHIFT	2
619 #define __SWP_TYPE_BITS		6
620 #define __SWP_OFFSET_BITS	50
621 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
622 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
623 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
624 
625 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
626 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
627 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
628 
629 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
630 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
631 
632 /*
633  * Ensure that there are not more swap files than can be encoded in the kernel
634  * PTEs.
635  */
636 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
637 
638 extern int kern_addr_valid(unsigned long addr);
639 
640 #include <asm-generic/pgtable.h>
641 
642 #define pgtable_cache_init() do { } while (0)
643 
644 /*
645  * On AArch64, the cache coherency is handled via the set_pte_at() function.
646  */
647 static inline void update_mmu_cache(struct vm_area_struct *vma,
648 				    unsigned long addr, pte_t *ptep)
649 {
650 	/*
651 	 * set_pte() does not have a DSB for user mappings, so make sure that
652 	 * the page table write is visible.
653 	 */
654 	dsb(ishst);
655 }
656 
657 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
658 
659 #endif /* !__ASSEMBLY__ */
660 
661 #endif /* __ASM_PGTABLE_H */
662