xref: /linux/arch/arm64/include/asm/pgtable.h (revision 324420bf91f60582bb481133db9547111768ef17)
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 <asm/fixmap.h>
61 #include <linux/mmdebug.h>
62 
63 extern void __pte_error(const char *file, int line, unsigned long val);
64 extern void __pmd_error(const char *file, int line, unsigned long val);
65 extern void __pud_error(const char *file, int line, unsigned long val);
66 extern void __pgd_error(const char *file, int line, unsigned long val);
67 
68 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
69 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
70 
71 #define PROT_DEVICE_nGnRnE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
72 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE))
73 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_NC))
74 #define PROT_NORMAL_WT		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_WT))
75 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL))
76 
77 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
78 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
79 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
80 
81 #define _PAGE_DEFAULT		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
82 
83 #define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
84 #define PAGE_KERNEL_RO		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_RDONLY)
85 #define PAGE_KERNEL_ROX		__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_RDONLY)
86 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
87 #define PAGE_KERNEL_EXEC_CONT	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT)
88 
89 #define PAGE_HYP		__pgprot(_PAGE_DEFAULT | PTE_HYP)
90 #define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
91 
92 #define PAGE_S2			__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
93 #define PAGE_S2_DEVICE		__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
94 
95 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
96 #define PAGE_SHARED		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
97 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
98 #define PAGE_COPY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
99 #define PAGE_COPY_EXEC		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
100 #define PAGE_READONLY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
101 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
102 
103 #define __P000  PAGE_NONE
104 #define __P001  PAGE_READONLY
105 #define __P010  PAGE_COPY
106 #define __P011  PAGE_COPY
107 #define __P100  PAGE_READONLY_EXEC
108 #define __P101  PAGE_READONLY_EXEC
109 #define __P110  PAGE_COPY_EXEC
110 #define __P111  PAGE_COPY_EXEC
111 
112 #define __S000  PAGE_NONE
113 #define __S001  PAGE_READONLY
114 #define __S010  PAGE_SHARED
115 #define __S011  PAGE_SHARED
116 #define __S100  PAGE_READONLY_EXEC
117 #define __S101  PAGE_READONLY_EXEC
118 #define __S110  PAGE_SHARED_EXEC
119 #define __S111  PAGE_SHARED_EXEC
120 
121 /*
122  * ZERO_PAGE is a global shared page that is always zero: used
123  * for zero-mapped memory areas etc..
124  */
125 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
126 #define ZERO_PAGE(vaddr)	virt_to_page(empty_zero_page)
127 
128 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
129 
130 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
131 
132 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
133 
134 #define pte_none(pte)		(!pte_val(pte))
135 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
136 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
137 
138 /*
139  * The following only work if pte_present(). Undefined behaviour otherwise.
140  */
141 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
142 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
143 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
144 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
145 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
146 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
147 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
148 
149 #ifdef CONFIG_ARM64_HW_AFDBM
150 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
151 #else
152 #define pte_hw_dirty(pte)	(0)
153 #endif
154 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
155 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
156 
157 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
158 #define pte_valid_not_user(pte) \
159 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
160 #define pte_valid_young(pte) \
161 	((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
162 
163 /*
164  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
165  * so that we don't erroneously return false for pages that have been
166  * remapped as PROT_NONE but are yet to be flushed from the TLB.
167  */
168 #define pte_accessible(mm, pte)	\
169 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
170 
171 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
172 {
173 	pte_val(pte) &= ~pgprot_val(prot);
174 	return pte;
175 }
176 
177 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
178 {
179 	pte_val(pte) |= pgprot_val(prot);
180 	return pte;
181 }
182 
183 static inline pte_t pte_wrprotect(pte_t pte)
184 {
185 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
186 }
187 
188 static inline pte_t pte_mkwrite(pte_t pte)
189 {
190 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
191 }
192 
193 static inline pte_t pte_mkclean(pte_t pte)
194 {
195 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
196 }
197 
198 static inline pte_t pte_mkdirty(pte_t pte)
199 {
200 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
201 }
202 
203 static inline pte_t pte_mkold(pte_t pte)
204 {
205 	return clear_pte_bit(pte, __pgprot(PTE_AF));
206 }
207 
208 static inline pte_t pte_mkyoung(pte_t pte)
209 {
210 	return set_pte_bit(pte, __pgprot(PTE_AF));
211 }
212 
213 static inline pte_t pte_mkspecial(pte_t pte)
214 {
215 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
216 }
217 
218 static inline pte_t pte_mkcont(pte_t pte)
219 {
220 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
221 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
222 }
223 
224 static inline pte_t pte_mknoncont(pte_t pte)
225 {
226 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
227 }
228 
229 static inline pmd_t pmd_mkcont(pmd_t pmd)
230 {
231 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
232 }
233 
234 static inline void set_pte(pte_t *ptep, pte_t pte)
235 {
236 	*ptep = pte;
237 
238 	/*
239 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
240 	 * or update_mmu_cache() have the necessary barriers.
241 	 */
242 	if (pte_valid_not_user(pte)) {
243 		dsb(ishst);
244 		isb();
245 	}
246 }
247 
248 struct mm_struct;
249 struct vm_area_struct;
250 
251 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
252 
253 /*
254  * PTE bits configuration in the presence of hardware Dirty Bit Management
255  * (PTE_WRITE == PTE_DBM):
256  *
257  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
258  *   0      0      |   1           0          0
259  *   0      1      |   1           1          0
260  *   1      0      |   1           0          1
261  *   1      1      |   0           1          x
262  *
263  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
264  * the page fault mechanism. Checking the dirty status of a pte becomes:
265  *
266  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
267  */
268 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
269 			      pte_t *ptep, pte_t pte)
270 {
271 	if (pte_valid(pte)) {
272 		if (pte_sw_dirty(pte) && pte_write(pte))
273 			pte_val(pte) &= ~PTE_RDONLY;
274 		else
275 			pte_val(pte) |= PTE_RDONLY;
276 		if (pte_user(pte) && pte_exec(pte) && !pte_special(pte))
277 			__sync_icache_dcache(pte, addr);
278 	}
279 
280 	/*
281 	 * If the existing pte is valid, check for potential race with
282 	 * hardware updates of the pte (ptep_set_access_flags safely changes
283 	 * valid ptes without going through an invalid entry).
284 	 */
285 	if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
286 	    pte_valid(*ptep) && pte_valid(pte)) {
287 		VM_WARN_ONCE(!pte_young(pte),
288 			     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
289 			     __func__, pte_val(*ptep), pte_val(pte));
290 		VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
291 			     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
292 			     __func__, pte_val(*ptep), pte_val(pte));
293 	}
294 
295 	set_pte(ptep, pte);
296 }
297 
298 /*
299  * Huge pte definitions.
300  */
301 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
302 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
303 
304 /*
305  * Hugetlb definitions.
306  */
307 #define HUGE_MAX_HSTATE		4
308 #define HPAGE_SHIFT		PMD_SHIFT
309 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
310 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
311 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
312 
313 #define __HAVE_ARCH_PTE_SPECIAL
314 
315 static inline pte_t pud_pte(pud_t pud)
316 {
317 	return __pte(pud_val(pud));
318 }
319 
320 static inline pmd_t pud_pmd(pud_t pud)
321 {
322 	return __pmd(pud_val(pud));
323 }
324 
325 static inline pte_t pmd_pte(pmd_t pmd)
326 {
327 	return __pte(pmd_val(pmd));
328 }
329 
330 static inline pmd_t pte_pmd(pte_t pte)
331 {
332 	return __pmd(pte_val(pte));
333 }
334 
335 static inline pgprot_t mk_sect_prot(pgprot_t prot)
336 {
337 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
338 }
339 
340 /*
341  * THP definitions.
342  */
343 
344 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
345 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
346 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
347 
348 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
349 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
350 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
351 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
352 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
353 #define pmd_mkclean(pmd)       pte_pmd(pte_mkclean(pmd_pte(pmd)))
354 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
355 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
356 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
357 
358 #define __HAVE_ARCH_PMD_WRITE
359 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
360 
361 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
362 
363 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
364 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
365 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
366 
367 #define pud_write(pud)		pte_write(pud_pte(pud))
368 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
369 
370 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
371 
372 static inline int has_transparent_hugepage(void)
373 {
374 	return 1;
375 }
376 
377 #define __pgprot_modify(prot,mask,bits) \
378 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
379 
380 /*
381  * Mark the prot value as uncacheable and unbufferable.
382  */
383 #define pgprot_noncached(prot) \
384 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
385 #define pgprot_writecombine(prot) \
386 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
387 #define pgprot_device(prot) \
388 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
389 #define __HAVE_PHYS_MEM_ACCESS_PROT
390 struct file;
391 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
392 				     unsigned long size, pgprot_t vma_prot);
393 
394 #define pmd_none(pmd)		(!pmd_val(pmd))
395 #define pmd_present(pmd)	(pmd_val(pmd))
396 
397 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
398 
399 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
400 				 PMD_TYPE_TABLE)
401 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
402 				 PMD_TYPE_SECT)
403 
404 #ifdef CONFIG_ARM64_64K_PAGES
405 #define pud_sect(pud)		(0)
406 #define pud_table(pud)		(1)
407 #else
408 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
409 				 PUD_TYPE_SECT)
410 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
411 				 PUD_TYPE_TABLE)
412 #endif
413 
414 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
415 {
416 	*pmdp = pmd;
417 	dsb(ishst);
418 	isb();
419 }
420 
421 static inline void pmd_clear(pmd_t *pmdp)
422 {
423 	set_pmd(pmdp, __pmd(0));
424 }
425 
426 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
427 {
428 	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
429 }
430 
431 /* Find an entry in the third-level page table. */
432 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
433 
434 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))
435 #define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
436 
437 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
438 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
439 #define pte_unmap(pte)			do { } while (0)
440 #define pte_unmap_nested(pte)		do { } while (0)
441 
442 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
443 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
444 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
445 
446 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
447 
448 /*
449  * Conversion functions: convert a page and protection to a page entry,
450  * and a page entry and page directory to the page they refer to.
451  */
452 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
453 
454 #if CONFIG_PGTABLE_LEVELS > 2
455 
456 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
457 
458 #define pud_none(pud)		(!pud_val(pud))
459 #define pud_bad(pud)		(!(pud_val(pud) & 2))
460 #define pud_present(pud)	(pud_val(pud))
461 
462 static inline void set_pud(pud_t *pudp, pud_t pud)
463 {
464 	*pudp = pud;
465 	dsb(ishst);
466 	isb();
467 }
468 
469 static inline void pud_clear(pud_t *pudp)
470 {
471 	set_pud(pudp, __pud(0));
472 }
473 
474 static inline phys_addr_t pud_page_paddr(pud_t pud)
475 {
476 	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
477 }
478 
479 /* Find an entry in the second-level page table. */
480 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
481 
482 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
483 #define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
484 
485 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
486 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
487 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
488 
489 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
490 
491 #else
492 
493 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
494 
495 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
496 #define pmd_set_fixmap(addr)		NULL
497 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
498 #define pmd_clear_fixmap()
499 
500 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
501 
502 #if CONFIG_PGTABLE_LEVELS > 3
503 
504 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
505 
506 #define pgd_none(pgd)		(!pgd_val(pgd))
507 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
508 #define pgd_present(pgd)	(pgd_val(pgd))
509 
510 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
511 {
512 	*pgdp = pgd;
513 	dsb(ishst);
514 }
515 
516 static inline void pgd_clear(pgd_t *pgdp)
517 {
518 	set_pgd(pgdp, __pgd(0));
519 }
520 
521 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
522 {
523 	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
524 }
525 
526 /* Find an entry in the frst-level page table. */
527 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
528 
529 #define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
530 #define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
531 
532 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
533 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
534 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
535 
536 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
537 
538 #else
539 
540 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
541 
542 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
543 #define pud_set_fixmap(addr)		NULL
544 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
545 #define pud_clear_fixmap()
546 
547 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
548 
549 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
550 
551 /* to find an entry in a page-table-directory */
552 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
553 
554 #define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
555 
556 #define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
557 
558 /* to find an entry in a kernel page-table-directory */
559 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
560 
561 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
562 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
563 
564 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
565 {
566 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
567 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
568 	/* preserve the hardware dirty information */
569 	if (pte_hw_dirty(pte))
570 		pte = pte_mkdirty(pte);
571 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
572 	return pte;
573 }
574 
575 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
576 {
577 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
578 }
579 
580 #ifdef CONFIG_ARM64_HW_AFDBM
581 /*
582  * Atomic pte/pmd modifications.
583  */
584 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
585 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
586 					    unsigned long address,
587 					    pte_t *ptep)
588 {
589 	pteval_t pteval;
590 	unsigned int tmp, res;
591 
592 	asm volatile("//	ptep_test_and_clear_young\n"
593 	"	prfm	pstl1strm, %2\n"
594 	"1:	ldxr	%0, %2\n"
595 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
596 	"	and	%0, %0, %4		// clear PTE_AF\n"
597 	"	stxr	%w1, %0, %2\n"
598 	"	cbnz	%w1, 1b\n"
599 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
600 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
601 
602 	return res;
603 }
604 
605 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
606 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
607 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
608 					    unsigned long address,
609 					    pmd_t *pmdp)
610 {
611 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
612 }
613 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
614 
615 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
616 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
617 				       unsigned long address, pte_t *ptep)
618 {
619 	pteval_t old_pteval;
620 	unsigned int tmp;
621 
622 	asm volatile("//	ptep_get_and_clear\n"
623 	"	prfm	pstl1strm, %2\n"
624 	"1:	ldxr	%0, %2\n"
625 	"	stxr	%w1, xzr, %2\n"
626 	"	cbnz	%w1, 1b\n"
627 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
628 
629 	return __pte(old_pteval);
630 }
631 
632 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
633 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
634 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
635 				       unsigned long address, pmd_t *pmdp)
636 {
637 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
638 }
639 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
640 
641 /*
642  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
643  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
644  */
645 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
646 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
647 {
648 	pteval_t pteval;
649 	unsigned long tmp;
650 
651 	asm volatile("//	ptep_set_wrprotect\n"
652 	"	prfm	pstl1strm, %2\n"
653 	"1:	ldxr	%0, %2\n"
654 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
655 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
656 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
657 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
658 	"	stxr	%w1, %0, %2\n"
659 	"	cbnz	%w1, 1b\n"
660 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
661 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
662 	: "cc");
663 }
664 
665 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
666 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
667 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
668 				      unsigned long address, pmd_t *pmdp)
669 {
670 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
671 }
672 #endif
673 #endif	/* CONFIG_ARM64_HW_AFDBM */
674 
675 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
676 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
677 
678 /*
679  * Encode and decode a swap entry:
680  *	bits 0-1:	present (must be zero)
681  *	bits 2-7:	swap type
682  *	bits 8-57:	swap offset
683  */
684 #define __SWP_TYPE_SHIFT	2
685 #define __SWP_TYPE_BITS		6
686 #define __SWP_OFFSET_BITS	50
687 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
688 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
689 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
690 
691 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
692 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
693 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
694 
695 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
696 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
697 
698 /*
699  * Ensure that there are not more swap files than can be encoded in the kernel
700  * PTEs.
701  */
702 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
703 
704 extern int kern_addr_valid(unsigned long addr);
705 
706 #include <asm-generic/pgtable.h>
707 
708 void pgd_cache_init(void);
709 #define pgtable_cache_init	pgd_cache_init
710 
711 /*
712  * On AArch64, the cache coherency is handled via the set_pte_at() function.
713  */
714 static inline void update_mmu_cache(struct vm_area_struct *vma,
715 				    unsigned long addr, pte_t *ptep)
716 {
717 	/*
718 	 * We don't do anything here, so there's a very small chance of
719 	 * us retaking a user fault which we just fixed up. The alternative
720 	 * is doing a dsb(ishst), but that penalises the fastpath.
721 	 */
722 }
723 
724 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
725 
726 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
727 #define kc_offset_to_vaddr(o)	((o) | VA_START)
728 
729 #endif /* !__ASSEMBLY__ */
730 
731 #endif /* __ASM_PGTABLE_H */
732