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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)	phys_to_page(__pa_symbol(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_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
75 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
76 
77 #ifdef CONFIG_ARM64_HW_AFDBM
78 #define pte_hw_dirty(pte)	(pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
79 #else
80 #define pte_hw_dirty(pte)	(0)
81 #endif
82 #define pte_sw_dirty(pte)	(!!(pte_val(pte) & PTE_DIRTY))
83 #define pte_dirty(pte)		(pte_sw_dirty(pte) || pte_hw_dirty(pte))
84 
85 #define pte_valid(pte)		(!!(pte_val(pte) & PTE_VALID))
86 /*
87  * Execute-only user mappings do not have the PTE_USER bit set. All valid
88  * kernel mappings have the PTE_UXN bit set.
89  */
90 #define pte_valid_not_user(pte) \
91 	((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
92 #define pte_valid_young(pte) \
93 	((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
94 #define pte_valid_user(pte) \
95 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
96 
97 /*
98  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
99  * so that we don't erroneously return false for pages that have been
100  * remapped as PROT_NONE but are yet to be flushed from the TLB.
101  */
102 #define pte_accessible(mm, pte)	\
103 	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
104 
105 /*
106  * p??_access_permitted() is true for valid user mappings (subject to the
107  * write permission check) other than user execute-only which do not have the
108  * PTE_USER bit set. PROT_NONE mappings do not have the PTE_VALID bit set.
109  */
110 #define pte_access_permitted(pte, write) \
111 	(pte_valid_user(pte) && (!(write) || pte_write(pte)))
112 #define pmd_access_permitted(pmd, write) \
113 	(pte_access_permitted(pmd_pte(pmd), (write)))
114 #define pud_access_permitted(pud, write) \
115 	(pte_access_permitted(pud_pte(pud), (write)))
116 
clear_pte_bit(pte_t pte,pgprot_t prot)117 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
118 {
119 	pte_val(pte) &= ~pgprot_val(prot);
120 	return pte;
121 }
122 
set_pte_bit(pte_t pte,pgprot_t prot)123 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
124 {
125 	pte_val(pte) |= pgprot_val(prot);
126 	return pte;
127 }
128 
pte_wrprotect(pte_t pte)129 static inline pte_t pte_wrprotect(pte_t pte)
130 {
131 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
132 }
133 
pte_mkwrite(pte_t pte)134 static inline pte_t pte_mkwrite(pte_t pte)
135 {
136 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
137 }
138 
pte_mkclean(pte_t pte)139 static inline pte_t pte_mkclean(pte_t pte)
140 {
141 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
142 }
143 
pte_mkdirty(pte_t pte)144 static inline pte_t pte_mkdirty(pte_t pte)
145 {
146 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
147 }
148 
pte_mkold(pte_t pte)149 static inline pte_t pte_mkold(pte_t pte)
150 {
151 	return clear_pte_bit(pte, __pgprot(PTE_AF));
152 }
153 
pte_mkyoung(pte_t pte)154 static inline pte_t pte_mkyoung(pte_t pte)
155 {
156 	return set_pte_bit(pte, __pgprot(PTE_AF));
157 }
158 
pte_mkspecial(pte_t pte)159 static inline pte_t pte_mkspecial(pte_t pte)
160 {
161 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
162 }
163 
pte_mkcont(pte_t pte)164 static inline pte_t pte_mkcont(pte_t pte)
165 {
166 	pte = set_pte_bit(pte, __pgprot(PTE_CONT));
167 	return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
168 }
169 
pte_mknoncont(pte_t pte)170 static inline pte_t pte_mknoncont(pte_t pte)
171 {
172 	return clear_pte_bit(pte, __pgprot(PTE_CONT));
173 }
174 
pte_clear_rdonly(pte_t pte)175 static inline pte_t pte_clear_rdonly(pte_t pte)
176 {
177 	return clear_pte_bit(pte, __pgprot(PTE_RDONLY));
178 }
179 
pte_mkpresent(pte_t pte)180 static inline pte_t pte_mkpresent(pte_t pte)
181 {
182 	return set_pte_bit(pte, __pgprot(PTE_VALID));
183 }
184 
pmd_mkcont(pmd_t pmd)185 static inline pmd_t pmd_mkcont(pmd_t pmd)
186 {
187 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
188 }
189 
set_pte(pte_t * ptep,pte_t pte)190 static inline void set_pte(pte_t *ptep, pte_t pte)
191 {
192 	*ptep = pte;
193 
194 	/*
195 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
196 	 * or update_mmu_cache() have the necessary barriers.
197 	 */
198 	if (pte_valid_not_user(pte)) {
199 		dsb(ishst);
200 		isb();
201 	}
202 }
203 
204 struct mm_struct;
205 struct vm_area_struct;
206 
207 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
208 
209 /*
210  * PTE bits configuration in the presence of hardware Dirty Bit Management
211  * (PTE_WRITE == PTE_DBM):
212  *
213  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
214  *   0      0      |   1           0          0
215  *   0      1      |   1           1          0
216  *   1      0      |   1           0          1
217  *   1      1      |   0           1          x
218  *
219  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
220  * the page fault mechanism. Checking the dirty status of a pte becomes:
221  *
222  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
223  */
set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte)224 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
225 			      pte_t *ptep, pte_t pte)
226 {
227 	if (pte_present(pte)) {
228 		if (pte_sw_dirty(pte) && pte_write(pte))
229 			pte_val(pte) &= ~PTE_RDONLY;
230 		else
231 			pte_val(pte) |= PTE_RDONLY;
232 		if (pte_user_exec(pte) && !pte_special(pte))
233 			__sync_icache_dcache(pte, addr);
234 	}
235 
236 	/*
237 	 * If the existing pte is valid, check for potential race with
238 	 * hardware updates of the pte (ptep_set_access_flags safely changes
239 	 * valid ptes without going through an invalid entry).
240 	 */
241 	if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) &&
242 	    pte_valid(*ptep) && pte_valid(pte)) {
243 		VM_WARN_ONCE(!pte_young(pte),
244 			     "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
245 			     __func__, pte_val(*ptep), pte_val(pte));
246 		VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
247 			     "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
248 			     __func__, pte_val(*ptep), pte_val(pte));
249 	}
250 
251 	set_pte(ptep, pte);
252 }
253 
254 #define __HAVE_ARCH_PTE_SAME
pte_same(pte_t pte_a,pte_t pte_b)255 static inline int pte_same(pte_t pte_a, pte_t pte_b)
256 {
257 	pteval_t lhs, rhs;
258 
259 	lhs = pte_val(pte_a);
260 	rhs = pte_val(pte_b);
261 
262 	if (pte_present(pte_a))
263 		lhs &= ~PTE_RDONLY;
264 
265 	if (pte_present(pte_b))
266 		rhs &= ~PTE_RDONLY;
267 
268 	return (lhs == rhs);
269 }
270 
271 /*
272  * Huge pte definitions.
273  */
274 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
275 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
276 
277 /*
278  * Hugetlb definitions.
279  */
280 #define HUGE_MAX_HSTATE		4
281 #define HPAGE_SHIFT		PMD_SHIFT
282 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
283 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
284 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
285 
286 #define __HAVE_ARCH_PTE_SPECIAL
287 
pud_pte(pud_t pud)288 static inline pte_t pud_pte(pud_t pud)
289 {
290 	return __pte(pud_val(pud));
291 }
292 
pud_pmd(pud_t pud)293 static inline pmd_t pud_pmd(pud_t pud)
294 {
295 	return __pmd(pud_val(pud));
296 }
297 
pmd_pte(pmd_t pmd)298 static inline pte_t pmd_pte(pmd_t pmd)
299 {
300 	return __pte(pmd_val(pmd));
301 }
302 
pte_pmd(pte_t pte)303 static inline pmd_t pte_pmd(pte_t pte)
304 {
305 	return __pmd(pte_val(pte));
306 }
307 
mk_sect_prot(pgprot_t prot)308 static inline pgprot_t mk_sect_prot(pgprot_t prot)
309 {
310 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
311 }
312 
313 #ifdef CONFIG_NUMA_BALANCING
314 /*
315  * See the comment in include/asm-generic/pgtable.h
316  */
pte_protnone(pte_t pte)317 static inline int pte_protnone(pte_t pte)
318 {
319 	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
320 }
321 
pmd_protnone(pmd_t pmd)322 static inline int pmd_protnone(pmd_t pmd)
323 {
324 	return pte_protnone(pmd_pte(pmd));
325 }
326 #endif
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 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
335 
336 #define pmd_present(pmd)	pte_present(pmd_pte(pmd))
337 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
338 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
339 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
340 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
341 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
342 #define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
343 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
344 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
345 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
346 
347 #define pmd_thp_or_huge(pmd)	(pmd_huge(pmd) || pmd_trans_huge(pmd))
348 
349 #define __HAVE_ARCH_PMD_WRITE
350 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
351 
352 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
353 
354 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
355 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
356 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
357 
358 #define pud_write(pud)		pte_write(pud_pte(pud))
359 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
360 
361 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
362 
363 #define __pgprot_modify(prot,mask,bits) \
364 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
365 
366 /*
367  * Mark the prot value as uncacheable and unbufferable.
368  */
369 #define pgprot_noncached(prot) \
370 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
371 #define pgprot_writecombine(prot) \
372 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
373 #define pgprot_device(prot) \
374 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
375 #define __HAVE_PHYS_MEM_ACCESS_PROT
376 struct file;
377 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
378 				     unsigned long size, pgprot_t vma_prot);
379 
380 #define pmd_none(pmd)		(!pmd_val(pmd))
381 
382 #define pmd_bad(pmd)		(!(pmd_val(pmd) & PMD_TABLE_BIT))
383 
384 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
385 				 PMD_TYPE_TABLE)
386 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
387 				 PMD_TYPE_SECT)
388 
389 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
390 #define pud_sect(pud)		(0)
391 #define pud_table(pud)		(1)
392 #else
393 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
394 				 PUD_TYPE_SECT)
395 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
396 				 PUD_TYPE_TABLE)
397 #endif
398 
set_pmd(pmd_t * pmdp,pmd_t pmd)399 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
400 {
401 	*pmdp = pmd;
402 	dsb(ishst);
403 	isb();
404 }
405 
pmd_clear(pmd_t * pmdp)406 static inline void pmd_clear(pmd_t *pmdp)
407 {
408 	set_pmd(pmdp, __pmd(0));
409 }
410 
pmd_page_paddr(pmd_t pmd)411 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
412 {
413 	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
414 }
415 
416 /* Find an entry in the third-level page table. */
417 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
418 
419 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))
420 #define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
421 
422 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
423 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
424 #define pte_unmap(pte)			do { } while (0)
425 #define pte_unmap_nested(pte)		do { } while (0)
426 
427 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
428 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
429 #define pte_clear_fixmap()		clear_fixmap(FIX_PTE)
430 
431 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
432 
433 /* use ONLY for statically allocated translation tables */
434 #define pte_offset_kimg(dir,addr)	((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
435 
436 /*
437  * Conversion functions: convert a page and protection to a page entry,
438  * and a page entry and page directory to the page they refer to.
439  */
440 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
441 
442 #if CONFIG_PGTABLE_LEVELS > 2
443 
444 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
445 
446 #define pud_none(pud)		(!pud_val(pud))
447 #define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
448 #define pud_present(pud)	(pud_val(pud))
449 
set_pud(pud_t * pudp,pud_t pud)450 static inline void set_pud(pud_t *pudp, pud_t pud)
451 {
452 	*pudp = pud;
453 	dsb(ishst);
454 	isb();
455 }
456 
pud_clear(pud_t * pudp)457 static inline void pud_clear(pud_t *pudp)
458 {
459 	set_pud(pudp, __pud(0));
460 }
461 
pud_page_paddr(pud_t pud)462 static inline phys_addr_t pud_page_paddr(pud_t pud)
463 {
464 	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
465 }
466 
467 /* Find an entry in the second-level page table. */
468 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
469 
470 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
471 #define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
472 
473 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
474 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
475 #define pmd_clear_fixmap()		clear_fixmap(FIX_PMD)
476 
477 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
478 
479 /* use ONLY for statically allocated translation tables */
480 #define pmd_offset_kimg(dir,addr)	((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
481 
482 #else
483 
484 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
485 
486 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
487 #define pmd_set_fixmap(addr)		NULL
488 #define pmd_set_fixmap_offset(pudp, addr)	((pmd_t *)pudp)
489 #define pmd_clear_fixmap()
490 
491 #define pmd_offset_kimg(dir,addr)	((pmd_t *)dir)
492 
493 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
494 
495 #if CONFIG_PGTABLE_LEVELS > 3
496 
497 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
498 
499 #define pgd_none(pgd)		(!pgd_val(pgd))
500 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
501 #define pgd_present(pgd)	(pgd_val(pgd))
502 
set_pgd(pgd_t * pgdp,pgd_t pgd)503 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
504 {
505 	*pgdp = pgd;
506 	dsb(ishst);
507 }
508 
pgd_clear(pgd_t * pgdp)509 static inline void pgd_clear(pgd_t *pgdp)
510 {
511 	set_pgd(pgdp, __pgd(0));
512 }
513 
pgd_page_paddr(pgd_t pgd)514 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
515 {
516 	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
517 }
518 
519 /* Find an entry in the frst-level page table. */
520 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
521 
522 #define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
523 #define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
524 
525 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
526 #define pud_set_fixmap_offset(pgd, addr)	pud_set_fixmap(pud_offset_phys(pgd, addr))
527 #define pud_clear_fixmap()		clear_fixmap(FIX_PUD)
528 
529 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
530 
531 /* use ONLY for statically allocated translation tables */
532 #define pud_offset_kimg(dir,addr)	((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
533 
534 #else
535 
536 #define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})
537 
538 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
539 #define pud_set_fixmap(addr)		NULL
540 #define pud_set_fixmap_offset(pgdp, addr)	((pud_t *)pgdp)
541 #define pud_clear_fixmap()
542 
543 #define pud_offset_kimg(dir,addr)	((pud_t *)dir)
544 
545 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
546 
547 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
548 
549 /* to find an entry in a page-table-directory */
550 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
551 
552 #define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
553 
554 #define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
555 
556 /* to find an entry in a kernel page-table-directory */
557 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
558 
559 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
560 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
561 
pte_modify(pte_t pte,pgprot_t newprot)562 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
563 {
564 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
565 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
566 	/* preserve the hardware dirty information */
567 	if (pte_hw_dirty(pte))
568 		pte = pte_mkdirty(pte);
569 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
570 	return pte;
571 }
572 
pmd_modify(pmd_t pmd,pgprot_t newprot)573 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
574 {
575 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
576 }
577 
578 #ifdef CONFIG_ARM64_HW_AFDBM
579 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
580 extern int ptep_set_access_flags(struct vm_area_struct *vma,
581 				 unsigned long address, pte_t *ptep,
582 				 pte_t entry, int dirty);
583 
584 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
585 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
pmdp_set_access_flags(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp,pmd_t entry,int dirty)586 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
587 					unsigned long address, pmd_t *pmdp,
588 					pmd_t entry, int dirty)
589 {
590 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
591 }
592 #endif
593 
594 /*
595  * Atomic pte/pmd modifications.
596  */
597 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
__ptep_test_and_clear_young(pte_t * ptep)598 static inline int __ptep_test_and_clear_young(pte_t *ptep)
599 {
600 	pteval_t pteval;
601 	unsigned int tmp, res;
602 
603 	asm volatile("//	__ptep_test_and_clear_young\n"
604 	"	prfm	pstl1strm, %2\n"
605 	"1:	ldxr	%0, %2\n"
606 	"	ubfx	%w3, %w0, %5, #1	// extract PTE_AF (young)\n"
607 	"	and	%0, %0, %4		// clear PTE_AF\n"
608 	"	stxr	%w1, %0, %2\n"
609 	"	cbnz	%w1, 1b\n"
610 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)), "=&r" (res)
611 	: "L" (~PTE_AF), "I" (ilog2(PTE_AF)));
612 
613 	return res;
614 }
615 
ptep_test_and_clear_young(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)616 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
617 					    unsigned long address,
618 					    pte_t *ptep)
619 {
620 	return __ptep_test_and_clear_young(ptep);
621 }
622 
623 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
624 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
pmdp_test_and_clear_young(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)625 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
626 					    unsigned long address,
627 					    pmd_t *pmdp)
628 {
629 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
630 }
631 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
632 
633 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
ptep_get_and_clear(struct mm_struct * mm,unsigned long address,pte_t * ptep)634 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
635 				       unsigned long address, pte_t *ptep)
636 {
637 	pteval_t old_pteval;
638 	unsigned int tmp;
639 
640 	asm volatile("//	ptep_get_and_clear\n"
641 	"	prfm	pstl1strm, %2\n"
642 	"1:	ldxr	%0, %2\n"
643 	"	stxr	%w1, xzr, %2\n"
644 	"	cbnz	%w1, 1b\n"
645 	: "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)));
646 
647 	return __pte(old_pteval);
648 }
649 
650 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
651 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
pmdp_huge_get_and_clear(struct mm_struct * mm,unsigned long address,pmd_t * pmdp)652 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
653 					    unsigned long address, pmd_t *pmdp)
654 {
655 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
656 }
657 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
658 
659 /*
660  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
661  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
662  */
663 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
ptep_set_wrprotect(struct mm_struct * mm,unsigned long address,pte_t * ptep)664 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
665 {
666 	pteval_t pteval;
667 	unsigned long tmp;
668 
669 	asm volatile("//	ptep_set_wrprotect\n"
670 	"	prfm	pstl1strm, %2\n"
671 	"1:	ldxr	%0, %2\n"
672 	"	tst	%0, %4			// check for hw dirty (!PTE_RDONLY)\n"
673 	"	csel	%1, %3, xzr, eq		// set PTE_DIRTY|PTE_RDONLY if dirty\n"
674 	"	orr	%0, %0, %1		// if !dirty, PTE_RDONLY is already set\n"
675 	"	and	%0, %0, %5		// clear PTE_WRITE/PTE_DBM\n"
676 	"	stxr	%w1, %0, %2\n"
677 	"	cbnz	%w1, 1b\n"
678 	: "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
679 	: "r" (PTE_DIRTY|PTE_RDONLY), "L" (PTE_RDONLY), "L" (~PTE_WRITE)
680 	: "cc");
681 }
682 
683 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
684 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
pmdp_set_wrprotect(struct mm_struct * mm,unsigned long address,pmd_t * pmdp)685 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
686 				      unsigned long address, pmd_t *pmdp)
687 {
688 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
689 }
690 #endif
691 #endif	/* CONFIG_ARM64_HW_AFDBM */
692 
693 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
694 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
695 extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
696 
697 /*
698  * Encode and decode a swap entry:
699  *	bits 0-1:	present (must be zero)
700  *	bits 2-7:	swap type
701  *	bits 8-57:	swap offset
702  *	bit  58:	PTE_PROT_NONE (must be zero)
703  */
704 #define __SWP_TYPE_SHIFT	2
705 #define __SWP_TYPE_BITS		6
706 #define __SWP_OFFSET_BITS	50
707 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
708 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
709 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
710 
711 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
712 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
713 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
714 
715 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
716 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
717 
718 /*
719  * Ensure that there are not more swap files than can be encoded in the kernel
720  * PTEs.
721  */
722 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
723 
724 extern int kern_addr_valid(unsigned long addr);
725 
726 #include <asm-generic/pgtable.h>
727 
728 void pgd_cache_init(void);
729 #define pgtable_cache_init	pgd_cache_init
730 
731 /*
732  * On AArch64, the cache coherency is handled via the set_pte_at() function.
733  */
update_mmu_cache(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)734 static inline void update_mmu_cache(struct vm_area_struct *vma,
735 				    unsigned long addr, pte_t *ptep)
736 {
737 	/*
738 	 * We don't do anything here, so there's a very small chance of
739 	 * us retaking a user fault which we just fixed up. The alternative
740 	 * is doing a dsb(ishst), but that penalises the fastpath.
741 	 */
742 }
743 
744 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
745 
746 #define kc_vaddr_to_offset(v)	((v) & ~VA_START)
747 #define kc_offset_to_vaddr(o)	((o) | VA_START)
748 
749 #endif /* !__ASSEMBLY__ */
750 
751 #endif /* __ASM_PGTABLE_H */
752