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/proc-fns.h>
20
21 #include <asm/memory.h>
22 #include <asm/pgtable-hwdef.h>
23
24 /*
25 * Software defined PTE bits definition.
26 */
27 #define PTE_VALID (_AT(pteval_t, 1) << 0)
28 #define PTE_DIRTY (_AT(pteval_t, 1) << 55)
29 #define PTE_SPECIAL (_AT(pteval_t, 1) << 56)
30 #define PTE_WRITE (_AT(pteval_t, 1) << 57)
31 #define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
32
33 /*
34 * VMALLOC and SPARSEMEM_VMEMMAP ranges.
35 *
36 * VMEMAP_SIZE: allows the whole linear region to be covered by a struct page array
37 * (rounded up to PUD_SIZE).
38 * VMALLOC_START: beginning of the kernel VA space
39 * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
40 * fixed mappings and modules
41 */
42 #define VMEMMAP_SIZE ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
43 #define VMALLOC_START (UL(0xffffffffffffffff) << VA_BITS)
44 #define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
45
46 #define VMEMMAP_START (VMALLOC_END + SZ_64K)
47 #define vmemmap ((struct page *)VMEMMAP_START - \
48 SECTION_ALIGN_DOWN(memstart_addr >> PAGE_SHIFT))
49
50 #define FIRST_USER_ADDRESS 0UL
51
52 #ifndef __ASSEMBLY__
53 extern void __pte_error(const char *file, int line, unsigned long val);
54 extern void __pmd_error(const char *file, int line, unsigned long val);
55 extern void __pud_error(const char *file, int line, unsigned long val);
56 extern void __pgd_error(const char *file, int line, unsigned long val);
57
58 #ifdef CONFIG_SMP
59 #define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
60 #define PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
61 #else
62 #define PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF)
63 #define PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF)
64 #endif
65
66 #define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
67 #define PROT_NORMAL_NC (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
68 #define PROT_NORMAL (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
69
70 #define PROT_SECT_DEVICE_nGnRE (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
71 #define PROT_SECT_NORMAL (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
72 #define PROT_SECT_NORMAL_EXEC (PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
73
74 #define _PAGE_DEFAULT (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
75
76 #define PAGE_KERNEL __pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
77 #define PAGE_KERNEL_EXEC __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
78
79 #define PAGE_HYP __pgprot(_PAGE_DEFAULT | PTE_HYP)
80 #define PAGE_HYP_DEVICE __pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
81
82 #define PAGE_S2 __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
83 #define PAGE_S2_DEVICE __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
84
85 #define PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
86 #define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
87 #define PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
88 #define PAGE_COPY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
89 #define PAGE_COPY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
90 #define PAGE_READONLY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
91 #define PAGE_READONLY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
92
93 #define __P000 PAGE_NONE
94 #define __P001 PAGE_READONLY
95 #define __P010 PAGE_COPY
96 #define __P011 PAGE_COPY
97 #define __P100 PAGE_READONLY_EXEC
98 #define __P101 PAGE_READONLY_EXEC
99 #define __P110 PAGE_COPY_EXEC
100 #define __P111 PAGE_COPY_EXEC
101
102 #define __S000 PAGE_NONE
103 #define __S001 PAGE_READONLY
104 #define __S010 PAGE_SHARED
105 #define __S011 PAGE_SHARED
106 #define __S100 PAGE_READONLY_EXEC
107 #define __S101 PAGE_READONLY_EXEC
108 #define __S110 PAGE_SHARED_EXEC
109 #define __S111 PAGE_SHARED_EXEC
110
111 /*
112 * ZERO_PAGE is a global shared page that is always zero: used
113 * for zero-mapped memory areas etc..
114 */
115 extern struct page *empty_zero_page;
116 #define ZERO_PAGE(vaddr) (empty_zero_page)
117
118 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
119
120 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
121
122 #define pfn_pte(pfn,prot) (__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
123
124 #define pte_none(pte) (!pte_val(pte))
125 #define pte_clear(mm,addr,ptep) set_pte(ptep, __pte(0))
126 #define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
127
128 /* Find an entry in the third-level page table. */
129 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
130
131 #define pte_offset_kernel(dir,addr) (pmd_page_vaddr(*(dir)) + pte_index(addr))
132
133 #define pte_offset_map(dir,addr) pte_offset_kernel((dir), (addr))
134 #define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
135 #define pte_unmap(pte) do { } while (0)
136 #define pte_unmap_nested(pte) do { } while (0)
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_dirty(pte) (!!(pte_val(pte) & PTE_DIRTY))
143 #define pte_young(pte) (!!(pte_val(pte) & PTE_AF))
144 #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL))
145 #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE))
146 #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN))
147
148 #define pte_valid_user(pte) \
149 ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
150 #define pte_valid_not_user(pte) \
151 ((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
152
clear_pte_bit(pte_t pte,pgprot_t prot)153 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
154 {
155 pte_val(pte) &= ~pgprot_val(prot);
156 return pte;
157 }
158
set_pte_bit(pte_t pte,pgprot_t prot)159 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
160 {
161 pte_val(pte) |= pgprot_val(prot);
162 return pte;
163 }
164
pte_wrprotect(pte_t pte)165 static inline pte_t pte_wrprotect(pte_t pte)
166 {
167 return clear_pte_bit(pte, __pgprot(PTE_WRITE));
168 }
169
pte_mkwrite(pte_t pte)170 static inline pte_t pte_mkwrite(pte_t pte)
171 {
172 return set_pte_bit(pte, __pgprot(PTE_WRITE));
173 }
174
pte_mkclean(pte_t pte)175 static inline pte_t pte_mkclean(pte_t pte)
176 {
177 return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
178 }
179
pte_mkdirty(pte_t pte)180 static inline pte_t pte_mkdirty(pte_t pte)
181 {
182 return set_pte_bit(pte, __pgprot(PTE_DIRTY));
183 }
184
pte_mkold(pte_t pte)185 static inline pte_t pte_mkold(pte_t pte)
186 {
187 return clear_pte_bit(pte, __pgprot(PTE_AF));
188 }
189
pte_mkyoung(pte_t pte)190 static inline pte_t pte_mkyoung(pte_t pte)
191 {
192 return set_pte_bit(pte, __pgprot(PTE_AF));
193 }
194
pte_mkspecial(pte_t pte)195 static inline pte_t pte_mkspecial(pte_t pte)
196 {
197 return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
198 }
199
set_pte(pte_t * ptep,pte_t pte)200 static inline void set_pte(pte_t *ptep, pte_t pte)
201 {
202 *ptep = pte;
203
204 /*
205 * Only if the new pte is valid and kernel, otherwise TLB maintenance
206 * or update_mmu_cache() have the necessary barriers.
207 */
208 if (pte_valid_not_user(pte)) {
209 dsb(ishst);
210 isb();
211 }
212 }
213
214 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
215
set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte)216 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
217 pte_t *ptep, pte_t pte)
218 {
219 if (pte_valid_user(pte)) {
220 if (!pte_special(pte) && pte_exec(pte))
221 __sync_icache_dcache(pte, addr);
222 if (pte_dirty(pte) && pte_write(pte))
223 pte_val(pte) &= ~PTE_RDONLY;
224 else
225 pte_val(pte) |= PTE_RDONLY;
226 }
227
228 set_pte(ptep, pte);
229 }
230
231 /*
232 * Huge pte definitions.
233 */
234 #define pte_huge(pte) (!(pte_val(pte) & PTE_TABLE_BIT))
235 #define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
236
237 /*
238 * Hugetlb definitions.
239 */
240 #define HUGE_MAX_HSTATE 2
241 #define HPAGE_SHIFT PMD_SHIFT
242 #define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT)
243 #define HPAGE_MASK (~(HPAGE_SIZE - 1))
244 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
245
246 #define __HAVE_ARCH_PTE_SPECIAL
247
pud_pte(pud_t pud)248 static inline pte_t pud_pte(pud_t pud)
249 {
250 return __pte(pud_val(pud));
251 }
252
pud_pmd(pud_t pud)253 static inline pmd_t pud_pmd(pud_t pud)
254 {
255 return __pmd(pud_val(pud));
256 }
257
pmd_pte(pmd_t pmd)258 static inline pte_t pmd_pte(pmd_t pmd)
259 {
260 return __pte(pmd_val(pmd));
261 }
262
pte_pmd(pte_t pte)263 static inline pmd_t pte_pmd(pte_t pte)
264 {
265 return __pmd(pte_val(pte));
266 }
267
mk_sect_prot(pgprot_t prot)268 static inline pgprot_t mk_sect_prot(pgprot_t prot)
269 {
270 return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
271 }
272
273 /*
274 * THP definitions.
275 */
276
277 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
278 #define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
279 #define pmd_trans_splitting(pmd) pte_special(pmd_pte(pmd))
280 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
281 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
282 struct vm_area_struct;
283 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
284 pmd_t *pmdp);
285 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
286 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
287
288 #define pmd_present(pmd) pte_present(pmd_pte(pmd))
289 #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd))
290 #define pmd_young(pmd) pte_young(pmd_pte(pmd))
291 #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd)))
292 #define pmd_mksplitting(pmd) pte_pmd(pte_mkspecial(pmd_pte(pmd)))
293 #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd)))
294 #define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd)))
295 #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd)))
296 #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd)))
297 #define pmd_mknotpresent(pmd) (__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
298
299 #define __HAVE_ARCH_PMD_WRITE
300 #define pmd_write(pmd) pte_write(pmd_pte(pmd))
301
302 #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
303
304 #define pmd_pfn(pmd) (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
305 #define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
306 #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot)
307
308 #define pud_write(pud) pte_write(pud_pte(pud))
309 #define pud_pfn(pud) (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
310
311 #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
312
has_transparent_hugepage(void)313 static inline int has_transparent_hugepage(void)
314 {
315 return 1;
316 }
317
318 #define __pgprot_modify(prot,mask,bits) \
319 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
320
321 /*
322 * Mark the prot value as uncacheable and unbufferable.
323 */
324 #define pgprot_noncached(prot) \
325 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
326 #define pgprot_writecombine(prot) \
327 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
328 #define pgprot_device(prot) \
329 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
330 #define __HAVE_PHYS_MEM_ACCESS_PROT
331 struct file;
332 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
333 unsigned long size, pgprot_t vma_prot);
334
335 #define pmd_none(pmd) (!pmd_val(pmd))
336
337 #define pmd_bad(pmd) (!(pmd_val(pmd) & 2))
338
339 #define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
340 PMD_TYPE_TABLE)
341 #define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
342 PMD_TYPE_SECT)
343
344 #ifdef CONFIG_ARM64_64K_PAGES
345 #define pud_sect(pud) (0)
346 #define pud_table(pud) (1)
347 #else
348 #define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
349 PUD_TYPE_SECT)
350 #define pud_table(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
351 PUD_TYPE_TABLE)
352 #endif
353
set_pmd(pmd_t * pmdp,pmd_t pmd)354 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
355 {
356 *pmdp = pmd;
357 dsb(ishst);
358 isb();
359 }
360
pmd_clear(pmd_t * pmdp)361 static inline void pmd_clear(pmd_t *pmdp)
362 {
363 set_pmd(pmdp, __pmd(0));
364 }
365
pmd_page_vaddr(pmd_t pmd)366 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
367 {
368 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
369 }
370
371 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
372
373 /*
374 * Conversion functions: convert a page and protection to a page entry,
375 * and a page entry and page directory to the page they refer to.
376 */
377 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page),prot)
378
379 #if CONFIG_PGTABLE_LEVELS > 2
380
381 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
382
383 #define pud_none(pud) (!pud_val(pud))
384 #define pud_bad(pud) (!(pud_val(pud) & 2))
385 #define pud_present(pud) (pud_val(pud))
386
set_pud(pud_t * pudp,pud_t pud)387 static inline void set_pud(pud_t *pudp, pud_t pud)
388 {
389 *pudp = pud;
390 dsb(ishst);
391 isb();
392 }
393
pud_clear(pud_t * pudp)394 static inline void pud_clear(pud_t *pudp)
395 {
396 set_pud(pudp, __pud(0));
397 }
398
pud_page_vaddr(pud_t pud)399 static inline pmd_t *pud_page_vaddr(pud_t pud)
400 {
401 return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
402 }
403
404 /* Find an entry in the second-level page table. */
405 #define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
406
pmd_offset(pud_t * pud,unsigned long addr)407 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
408 {
409 return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
410 }
411
412 #define pud_page(pud) pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
413
414 #endif /* CONFIG_PGTABLE_LEVELS > 2 */
415
416 #if CONFIG_PGTABLE_LEVELS > 3
417
418 #define pud_ERROR(pud) __pud_error(__FILE__, __LINE__, pud_val(pud))
419
420 #define pgd_none(pgd) (!pgd_val(pgd))
421 #define pgd_bad(pgd) (!(pgd_val(pgd) & 2))
422 #define pgd_present(pgd) (pgd_val(pgd))
423
set_pgd(pgd_t * pgdp,pgd_t pgd)424 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
425 {
426 *pgdp = pgd;
427 dsb(ishst);
428 }
429
pgd_clear(pgd_t * pgdp)430 static inline void pgd_clear(pgd_t *pgdp)
431 {
432 set_pgd(pgdp, __pgd(0));
433 }
434
pgd_page_vaddr(pgd_t pgd)435 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
436 {
437 return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
438 }
439
440 /* Find an entry in the frst-level page table. */
441 #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
442
pud_offset(pgd_t * pgd,unsigned long addr)443 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
444 {
445 return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
446 }
447
448 #define pgd_page(pgd) pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
449
450 #endif /* CONFIG_PGTABLE_LEVELS > 3 */
451
452 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
453
454 /* to find an entry in a page-table-directory */
455 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
456
457 #define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))
458
459 /* to find an entry in a kernel page-table-directory */
460 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
461
pte_modify(pte_t pte,pgprot_t newprot)462 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
463 {
464 const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
465 PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
466 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
467 return pte;
468 }
469
pmd_modify(pmd_t pmd,pgprot_t newprot)470 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
471 {
472 return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
473 }
474
475 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
476 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
477
478 /*
479 * Encode and decode a swap entry:
480 * bits 0-1: present (must be zero)
481 * bits 2-7: swap type
482 * bits 8-57: swap offset
483 */
484 #define __SWP_TYPE_SHIFT 2
485 #define __SWP_TYPE_BITS 6
486 #define __SWP_OFFSET_BITS 50
487 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
488 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
489 #define __SWP_OFFSET_MASK ((1UL << __SWP_OFFSET_BITS) - 1)
490
491 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
492 #define __swp_offset(x) (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
493 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
494
495 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
496 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
497
498 /*
499 * Ensure that there are not more swap files than can be encoded in the kernel
500 * PTEs.
501 */
502 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
503
504 extern int kern_addr_valid(unsigned long addr);
505
506 #include <asm-generic/pgtable.h>
507
508 #define pgtable_cache_init() do { } while (0)
509
510 #endif /* !__ASSEMBLY__ */
511
512 #endif /* __ASM_PGTABLE_H */
513