xref: /linux/arch/arm64/include/asm/pgtable.h (revision fc4fa6e112c0f999fab022a4eb7f6614bb47c7ab)
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 
45 #ifndef CONFIG_KASAN
46 #define VMALLOC_START		(VA_START)
47 #else
48 #include <asm/kasan.h>
49 #define VMALLOC_START		(KASAN_SHADOW_END + SZ_64K)
50 #endif
51 
52 #define VMALLOC_END		(PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
53 
54 #define vmemmap			((struct page *)(VMALLOC_END + SZ_64K))
55 
56 #define FIRST_USER_ADDRESS	0UL
57 
58 #ifndef __ASSEMBLY__
59 
60 #include <linux/mmdebug.h>
61 
62 extern void __pte_error(const char *file, int line, unsigned long val);
63 extern void __pmd_error(const char *file, int line, unsigned long val);
64 extern void __pud_error(const char *file, int line, unsigned long val);
65 extern void __pgd_error(const char *file, int line, unsigned long val);
66 
67 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
68 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
69 
70 #define PROT_DEVICE_nGnRnE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
71 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
72 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
73 #define PROT_NORMAL_WT		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_WT))
74 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
75 
76 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
77 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
78 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
79 
80 #define _PAGE_DEFAULT		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
81 
82 #define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
83 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
84 #define PAGE_KERNEL_EXEC_CONT	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT)
85 
86 #define PAGE_HYP		__pgprot(_PAGE_DEFAULT | PTE_HYP)
87 #define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
88 
89 #define PAGE_S2			__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
90 #define PAGE_S2_DEVICE		__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
91 
92 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
93 #define PAGE_SHARED		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
94 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
95 #define PAGE_COPY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
96 #define PAGE_COPY_EXEC		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
97 #define PAGE_READONLY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
98 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
99 
100 #define __P000  PAGE_NONE
101 #define __P001  PAGE_READONLY
102 #define __P010  PAGE_COPY
103 #define __P011  PAGE_COPY
104 #define __P100  PAGE_READONLY_EXEC
105 #define __P101  PAGE_READONLY_EXEC
106 #define __P110  PAGE_COPY_EXEC
107 #define __P111  PAGE_COPY_EXEC
108 
109 #define __S000  PAGE_NONE
110 #define __S001  PAGE_READONLY
111 #define __S010  PAGE_SHARED
112 #define __S011  PAGE_SHARED
113 #define __S100  PAGE_READONLY_EXEC
114 #define __S101  PAGE_READONLY_EXEC
115 #define __S110  PAGE_SHARED_EXEC
116 #define __S111  PAGE_SHARED_EXEC
117 
118 /*
119  * ZERO_PAGE is a global shared page that is always zero: used
120  * for zero-mapped memory areas etc..
121  */
122 extern struct page *empty_zero_page;
123 #define ZERO_PAGE(vaddr)	(empty_zero_page)
124 
125 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
126 
127 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
128 
129 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
130 
131 #define pte_none(pte)		(!pte_val(pte))
132 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
133 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
134 
135 /* Find an entry in the third-level page table. */
136 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
137 
138 #define pte_offset_kernel(dir,addr)	(pmd_page_vaddr(*(dir)) + pte_index(addr))
139 
140 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
141 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
142 #define pte_unmap(pte)			do { } while (0)
143 #define pte_unmap_nested(pte)		do { } while (0)
144 
145 /*
146  * The following only work if pte_present(). Undefined behaviour otherwise.
147  */
148 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
149 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
150 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
151 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
152 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
153 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
154 
155 #ifdef CONFIG_ARM64_HW_AFDBM
156 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
157 #else
158 #define pte_hw_dirty(pte)	(0)
159 #endif
160 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
161 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
162 
163 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
164 #define pte_valid_user(pte) \
165 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
166 #define pte_valid_not_user(pte) \
167 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
168 
169 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
170 {
171 	pte_val(pte) &= ~pgprot_val(prot);
172 	return pte;
173 }
174 
175 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
176 {
177 	pte_val(pte) |= pgprot_val(prot);
178 	return pte;
179 }
180 
181 static inline pte_t pte_wrprotect(pte_t pte)
182 {
183 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
184 }
185 
186 static inline pte_t pte_mkwrite(pte_t pte)
187 {
188 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
189 }
190 
191 static inline pte_t pte_mkclean(pte_t pte)
192 {
193 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
194 }
195 
196 static inline pte_t pte_mkdirty(pte_t pte)
197 {
198 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
199 }
200 
201 static inline pte_t pte_mkold(pte_t pte)
202 {
203 	return clear_pte_bit(pte, __pgprot(PTE_AF));
204 }
205 
206 static inline pte_t pte_mkyoung(pte_t pte)
207 {
208 	return set_pte_bit(pte, __pgprot(PTE_AF));
209 }
210 
211 static inline pte_t pte_mkspecial(pte_t pte)
212 {
213 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
214 }
215 
216 static inline pte_t pte_mkcont(pte_t pte)
217 {
218 	return set_pte_bit(pte, __pgprot(PTE_CONT));
219 }
220 
221 static inline pte_t pte_mknoncont(pte_t pte)
222 {
223 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
224 }
225 
226 static inline void set_pte(pte_t *ptep, pte_t pte)
227 {
228 	*ptep = pte;
229 
230 	/*
231 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
232 	 * or update_mmu_cache() have the necessary barriers.
233 	 */
234 	if (pte_valid_not_user(pte)) {
235 		dsb(ishst);
236 		isb();
237 	}
238 }
239 
240 struct mm_struct;
241 struct vm_area_struct;
242 
243 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
244 
245 /*
246  * PTE bits configuration in the presence of hardware Dirty Bit Management
247  * (PTE_WRITE == PTE_DBM):
248  *
249  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
250  *   0      0      |   1           0          0
251  *   0      1      |   1           1          0
252  *   1      0      |   1           0          1
253  *   1      1      |   0           1          x
254  *
255  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
256  * the page fault mechanism. Checking the dirty status of a pte becomes:
257  *
258  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
259  */
260 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
261 			      pte_t *ptep, pte_t pte)
262 {
263 	if (pte_valid_user(pte)) {
264 		if (!pte_special(pte) && pte_exec(pte))
265 			__sync_icache_dcache(pte, addr);
266 		if (pte_sw_dirty(pte) && pte_write(pte))
267 			pte_val(pte) &= ~PTE_RDONLY;
268 		else
269 			pte_val(pte) |= PTE_RDONLY;
270 	}
271 
272 	/*
273 	 * If the existing pte is valid, check for potential race with
274 	 * hardware updates of the pte (ptep_set_access_flags safely changes
275 	 * valid ptes without going through an invalid entry).
276 	 */
277 	if (IS_ENABLED(CONFIG_DEBUG_VM) && IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
278 	    pte_valid(*ptep)) {
279 		BUG_ON(!pte_young(pte));
280 		BUG_ON(pte_write(*ptep) && !pte_dirty(pte));
281 	}
282 
283 	set_pte(ptep, pte);
284 }
285 
286 /*
287  * Huge pte definitions.
288  */
289 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
290 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
291 
292 /*
293  * Hugetlb definitions.
294  */
295 #define HUGE_MAX_HSTATE		2
296 #define HPAGE_SHIFT		PMD_SHIFT
297 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
298 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
299 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
300 
301 #define __HAVE_ARCH_PTE_SPECIAL
302 
303 static inline pte_t pud_pte(pud_t pud)
304 {
305 	return __pte(pud_val(pud));
306 }
307 
308 static inline pmd_t pud_pmd(pud_t pud)
309 {
310 	return __pmd(pud_val(pud));
311 }
312 
313 static inline pte_t pmd_pte(pmd_t pmd)
314 {
315 	return __pte(pmd_val(pmd));
316 }
317 
318 static inline pmd_t pte_pmd(pte_t pte)
319 {
320 	return __pmd(pte_val(pte));
321 }
322 
323 static inline pgprot_t mk_sect_prot(pgprot_t prot)
324 {
325 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
326 }
327 
328 /*
329  * THP definitions.
330  */
331 
332 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
333 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
334 #define pmd_trans_splitting(pmd)	pte_special(pmd_pte(pmd))
335 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
336 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
337 struct vm_area_struct;
338 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
339 			  pmd_t *pmdp);
340 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
341 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
342 
343 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
344 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
345 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
346 #define pmd_mksplitting(pmd)	pte_pmd(pte_mkspecial(pmd_pte(pmd)))
347 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
348 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
349 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
350 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
351 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
352 
353 #define __HAVE_ARCH_PMD_WRITE
354 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
355 
356 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
357 
358 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
359 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
360 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
361 
362 #define pud_write(pud)		pte_write(pud_pte(pud))
363 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
364 
365 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
366 
367 static inline int has_transparent_hugepage(void)
368 {
369 	return 1;
370 }
371 
372 #define __pgprot_modify(prot,mask,bits) \
373 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
374 
375 /*
376  * Mark the prot value as uncacheable and unbufferable.
377  */
378 #define pgprot_noncached(prot) \
379 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
380 #define pgprot_writecombine(prot) \
381 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
382 #define pgprot_device(prot) \
383 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
384 #define __HAVE_PHYS_MEM_ACCESS_PROT
385 struct file;
386 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
387 				     unsigned long size, pgprot_t vma_prot);
388 
389 #define pmd_none(pmd)		(!pmd_val(pmd))
390 #define pmd_present(pmd)	(pmd_val(pmd))
391 
392 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
393 
394 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
395 				 PMD_TYPE_TABLE)
396 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
397 				 PMD_TYPE_SECT)
398 
399 #ifdef CONFIG_ARM64_64K_PAGES
400 #define pud_sect(pud)		(0)
401 #define pud_table(pud)		(1)
402 #else
403 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
404 				 PUD_TYPE_SECT)
405 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
406 				 PUD_TYPE_TABLE)
407 #endif
408 
409 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
410 {
411 	*pmdp = pmd;
412 	dsb(ishst);
413 	isb();
414 }
415 
416 static inline void pmd_clear(pmd_t *pmdp)
417 {
418 	set_pmd(pmdp, __pmd(0));
419 }
420 
421 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
422 {
423 	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
424 }
425 
426 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
427 
428 /*
429  * Conversion functions: convert a page and protection to a page entry,
430  * and a page entry and page directory to the page they refer to.
431  */
432 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
433 
434 #if CONFIG_PGTABLE_LEVELS > 2
435 
436 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
437 
438 #define pud_none(pud)		(!pud_val(pud))
439 #define pud_bad(pud)		(!(pud_val(pud) & 2))
440 #define pud_present(pud)	(pud_val(pud))
441 
442 static inline void set_pud(pud_t *pudp, pud_t pud)
443 {
444 	*pudp = pud;
445 	dsb(ishst);
446 	isb();
447 }
448 
449 static inline void pud_clear(pud_t *pudp)
450 {
451 	set_pud(pudp, __pud(0));
452 }
453 
454 static inline pmd_t *pud_page_vaddr(pud_t pud)
455 {
456 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
457 }
458 
459 /* Find an entry in the second-level page table. */
460 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
461 
462 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
463 {
464 	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
465 }
466 
467 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
468 
469 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
470 
471 #if CONFIG_PGTABLE_LEVELS > 3
472 
473 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
474 
475 #define pgd_none(pgd)		(!pgd_val(pgd))
476 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
477 #define pgd_present(pgd)	(pgd_val(pgd))
478 
479 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
480 {
481 	*pgdp = pgd;
482 	dsb(ishst);
483 }
484 
485 static inline void pgd_clear(pgd_t *pgdp)
486 {
487 	set_pgd(pgdp, __pgd(0));
488 }
489 
490 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
491 {
492 	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
493 }
494 
495 /* Find an entry in the frst-level page table. */
496 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
497 
498 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
499 {
500 	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
501 }
502 
503 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
504 
505 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
506 
507 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
508 
509 /* to find an entry in a page-table-directory */
510 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
511 
512 #define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))
513 
514 /* to find an entry in a kernel page-table-directory */
515 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
516 
517 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
518 {
519 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
520 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
521 	/* preserve the hardware dirty information */
522 	if (pte_hw_dirty(pte))
523 		pte = pte_mkdirty(pte);
524 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
525 	return pte;
526 }
527 
528 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
529 {
530 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
531 }
532 
533 #ifdef CONFIG_ARM64_HW_AFDBM
534 /*
535  * Atomic pte/pmd modifications.
536  */
537 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
538 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
539 					    unsigned long address,
540 					    pte_t *ptep)
541 {
542 	pteval_t pteval;
543 	unsigned int tmp, res;
544 
545 	asm volatile("//	ptep_test_and_clear_young\n"
546 	"	prfm	pstl1strm, %2\n"
547 	"1:	ldxr	%0, %2\n"
548 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
549 	"	and	%0, %0, %4		// clear PTE_AF\n"
550 	"	stxr	%w1, %0, %2\n"
551 	"	cbnz	%w1, 1b\n"
552 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
553 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
554 
555 	return res;
556 }
557 
558 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
559 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
560 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
561 					    unsigned long address,
562 					    pmd_t *pmdp)
563 {
564 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
565 }
566 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
567 
568 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
569 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
570 				       unsigned long address, pte_t *ptep)
571 {
572 	pteval_t old_pteval;
573 	unsigned int tmp;
574 
575 	asm volatile("//	ptep_get_and_clear\n"
576 	"	prfm	pstl1strm, %2\n"
577 	"1:	ldxr	%0, %2\n"
578 	"	stxr	%w1, xzr, %2\n"
579 	"	cbnz	%w1, 1b\n"
580 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
581 
582 	return __pte(old_pteval);
583 }
584 
585 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
586 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
587 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
588 				       unsigned long address, pmd_t *pmdp)
589 {
590 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
591 }
592 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
593 
594 /*
595  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
596  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
597  */
598 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
599 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
600 {
601 	pteval_t pteval;
602 	unsigned long tmp;
603 
604 	asm volatile("//	ptep_set_wrprotect\n"
605 	"	prfm	pstl1strm, %2\n"
606 	"1:	ldxr	%0, %2\n"
607 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
608 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
609 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
610 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
611 	"	stxr	%w1, %0, %2\n"
612 	"	cbnz	%w1, 1b\n"
613 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
614 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
615 	: "cc");
616 }
617 
618 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
619 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
620 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
621 				      unsigned long address, pmd_t *pmdp)
622 {
623 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
624 }
625 #endif
626 #endif	/* CONFIG_ARM64_HW_AFDBM */
627 
628 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
629 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
630 
631 /*
632  * Encode and decode a swap entry:
633  *	bits 0-1:	present (must be zero)
634  *	bits 2-7:	swap type
635  *	bits 8-57:	swap offset
636  */
637 #define __SWP_TYPE_SHIFT	2
638 #define __SWP_TYPE_BITS		6
639 #define __SWP_OFFSET_BITS	50
640 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
641 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
642 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
643 
644 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
645 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
646 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
647 
648 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
649 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
650 
651 /*
652  * Ensure that there are not more swap files than can be encoded in the kernel
653  * PTEs.
654  */
655 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
656 
657 extern int kern_addr_valid(unsigned long addr);
658 
659 #include <asm-generic/pgtable.h>
660 
661 #define pgtable_cache_init() do { } while (0)
662 
663 /*
664  * On AArch64, the cache coherency is handled via the set_pte_at() function.
665  */
666 static inline void update_mmu_cache(struct vm_area_struct *vma,
667 				    unsigned long addr, pte_t *ptep)
668 {
669 	/*
670 	 * We don't do anything here, so there's a very small chance of
671 	 * us retaking a user fault which we just fixed up. The alternative
672 	 * is doing a dsb(ishst), but that penalises the fastpath.
673 	 */
674 }
675 
676 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
677 
678 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
679 #define kc_offset_to_vaddr(o)	((o) | VA_START)
680 
681 #endif /* !__ASSEMBLY__ */
682 
683 #endif /* __ASM_PGTABLE_H */
684