xref: /linux/arch/arm64/include/asm/pgtable.h (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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_FILE		(_AT(pteval_t, 1) << 2)	/* only when !pte_present() */
29 #define PTE_DIRTY		(_AT(pteval_t, 1) << 55)
30 #define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)
31 #define PTE_WRITE		(_AT(pteval_t, 1) << 57)
32 #define PTE_PROT_NONE		(_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
33 
34 /*
35  * VMALLOC and SPARSEMEM_VMEMMAP ranges.
36  *
37  * VMEMAP_SIZE: allows the whole VA space to be covered by a struct page array
38  *	(rounded up to PUD_SIZE).
39  * VMALLOC_START: beginning of the kernel VA space
40  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
41  *	fixed mappings and modules
42  */
43 #define VMEMMAP_SIZE		ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
44 #define VMALLOC_START		(UL(0xffffffffffffffff) << VA_BITS)
45 #define VMALLOC_END		(PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
46 
47 #define vmemmap			((struct page *)(VMALLOC_END + SZ_64K))
48 
49 #define FIRST_USER_ADDRESS	0
50 
51 #ifndef __ASSEMBLY__
52 extern void __pte_error(const char *file, int line, unsigned long val);
53 extern void __pmd_error(const char *file, int line, unsigned long val);
54 extern void __pud_error(const char *file, int line, unsigned long val);
55 extern void __pgd_error(const char *file, int line, unsigned long val);
56 
57 #ifdef CONFIG_SMP
58 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
59 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
60 #else
61 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF)
62 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF)
63 #endif
64 
65 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
66 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
67 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
68 
69 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
70 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
71 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
72 
73 #define _PAGE_DEFAULT		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
74 
75 #define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
76 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
77 
78 #define PAGE_HYP		__pgprot(_PAGE_DEFAULT | PTE_HYP)
79 #define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
80 
81 #define PAGE_S2			__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
82 #define PAGE_S2_DEVICE		__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
83 
84 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
85 #define PAGE_SHARED		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
86 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
87 #define PAGE_COPY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
88 #define PAGE_COPY_EXEC		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
89 #define PAGE_READONLY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
90 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
91 
92 #define __P000  PAGE_NONE
93 #define __P001  PAGE_READONLY
94 #define __P010  PAGE_COPY
95 #define __P011  PAGE_COPY
96 #define __P100  PAGE_READONLY_EXEC
97 #define __P101  PAGE_READONLY_EXEC
98 #define __P110  PAGE_COPY_EXEC
99 #define __P111  PAGE_COPY_EXEC
100 
101 #define __S000  PAGE_NONE
102 #define __S001  PAGE_READONLY
103 #define __S010  PAGE_SHARED
104 #define __S011  PAGE_SHARED
105 #define __S100  PAGE_READONLY_EXEC
106 #define __S101  PAGE_READONLY_EXEC
107 #define __S110  PAGE_SHARED_EXEC
108 #define __S111  PAGE_SHARED_EXEC
109 
110 /*
111  * ZERO_PAGE is a global shared page that is always zero: used
112  * for zero-mapped memory areas etc..
113  */
114 extern struct page *empty_zero_page;
115 #define ZERO_PAGE(vaddr)	(empty_zero_page)
116 
117 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
118 
119 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
120 
121 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
122 
123 #define pte_none(pte)		(!pte_val(pte))
124 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
125 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
126 
127 /* Find an entry in the third-level page table. */
128 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
129 
130 #define pte_offset_kernel(dir,addr)	(pmd_page_vaddr(*(dir)) + pte_index(addr))
131 
132 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
133 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
134 #define pte_unmap(pte)			do { } while (0)
135 #define pte_unmap_nested(pte)		do { } while (0)
136 
137 /*
138  * The following only work if pte_present(). Undefined behaviour otherwise.
139  */
140 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
141 #define pte_dirty(pte)		(!!(pte_val(pte) & PTE_DIRTY))
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 
147 #define pte_valid_user(pte) \
148 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
149 #define pte_valid_not_user(pte) \
150 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
151 
152 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
153 {
154 	pte_val(pte) &= ~pgprot_val(prot);
155 	return pte;
156 }
157 
158 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
159 {
160 	pte_val(pte) |= pgprot_val(prot);
161 	return pte;
162 }
163 
164 static inline pte_t pte_wrprotect(pte_t pte)
165 {
166 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
167 }
168 
169 static inline pte_t pte_mkwrite(pte_t pte)
170 {
171 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
172 }
173 
174 static inline pte_t pte_mkclean(pte_t pte)
175 {
176 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
177 }
178 
179 static inline pte_t pte_mkdirty(pte_t pte)
180 {
181 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
182 }
183 
184 static inline pte_t pte_mkold(pte_t pte)
185 {
186 	return clear_pte_bit(pte, __pgprot(PTE_AF));
187 }
188 
189 static inline pte_t pte_mkyoung(pte_t pte)
190 {
191 	return set_pte_bit(pte, __pgprot(PTE_AF));
192 }
193 
194 static inline pte_t pte_mkspecial(pte_t pte)
195 {
196 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
197 }
198 
199 static inline void set_pte(pte_t *ptep, pte_t pte)
200 {
201 	*ptep = pte;
202 
203 	/*
204 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
205 	 * or update_mmu_cache() have the necessary barriers.
206 	 */
207 	if (pte_valid_not_user(pte)) {
208 		dsb(ishst);
209 		isb();
210 	}
211 }
212 
213 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
214 
215 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
216 			      pte_t *ptep, pte_t pte)
217 {
218 	if (pte_valid_user(pte)) {
219 		if (!pte_special(pte) && pte_exec(pte))
220 			__sync_icache_dcache(pte, addr);
221 		if (pte_dirty(pte) && pte_write(pte))
222 			pte_val(pte) &= ~PTE_RDONLY;
223 		else
224 			pte_val(pte) |= PTE_RDONLY;
225 	}
226 
227 	set_pte(ptep, pte);
228 }
229 
230 /*
231  * Huge pte definitions.
232  */
233 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
234 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
235 
236 /*
237  * Hugetlb definitions.
238  */
239 #define HUGE_MAX_HSTATE		2
240 #define HPAGE_SHIFT		PMD_SHIFT
241 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
242 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
243 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
244 
245 #define __HAVE_ARCH_PTE_SPECIAL
246 
247 static inline pte_t pud_pte(pud_t pud)
248 {
249 	return __pte(pud_val(pud));
250 }
251 
252 static inline pmd_t pud_pmd(pud_t pud)
253 {
254 	return __pmd(pud_val(pud));
255 }
256 
257 static inline pte_t pmd_pte(pmd_t pmd)
258 {
259 	return __pte(pmd_val(pmd));
260 }
261 
262 static inline pmd_t pte_pmd(pte_t pte)
263 {
264 	return __pmd(pte_val(pte));
265 }
266 
267 /*
268  * THP definitions.
269  */
270 
271 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
272 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
273 #define pmd_trans_splitting(pmd)	pte_special(pmd_pte(pmd))
274 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
275 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
276 struct vm_area_struct;
277 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
278 			  pmd_t *pmdp);
279 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
280 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
281 
282 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
283 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
284 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
285 #define pmd_mksplitting(pmd)	pte_pmd(pte_mkspecial(pmd_pte(pmd)))
286 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
287 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
288 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
289 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
290 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
291 
292 #define __HAVE_ARCH_PMD_WRITE
293 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
294 
295 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
296 
297 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
298 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
299 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
300 
301 #define pud_write(pud)		pte_write(pud_pte(pud))
302 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
303 
304 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
305 
306 static inline int has_transparent_hugepage(void)
307 {
308 	return 1;
309 }
310 
311 #define __pgprot_modify(prot,mask,bits) \
312 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
313 
314 /*
315  * Mark the prot value as uncacheable and unbufferable.
316  */
317 #define pgprot_noncached(prot) \
318 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
319 #define pgprot_writecombine(prot) \
320 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
321 #define pgprot_device(prot) \
322 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
323 #define __HAVE_PHYS_MEM_ACCESS_PROT
324 struct file;
325 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
326 				     unsigned long size, pgprot_t vma_prot);
327 
328 #define pmd_none(pmd)		(!pmd_val(pmd))
329 #define pmd_present(pmd)	(pmd_val(pmd))
330 
331 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
332 
333 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
334 				 PMD_TYPE_TABLE)
335 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
336 				 PMD_TYPE_SECT)
337 
338 #ifdef CONFIG_ARM64_64K_PAGES
339 #define pud_sect(pud)		(0)
340 #else
341 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
342 				 PUD_TYPE_SECT)
343 #endif
344 
345 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
346 {
347 	*pmdp = pmd;
348 	dsb(ishst);
349 	isb();
350 }
351 
352 static inline void pmd_clear(pmd_t *pmdp)
353 {
354 	set_pmd(pmdp, __pmd(0));
355 }
356 
357 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
358 {
359 	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
360 }
361 
362 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
363 
364 /*
365  * Conversion functions: convert a page and protection to a page entry,
366  * and a page entry and page directory to the page they refer to.
367  */
368 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
369 
370 #if CONFIG_ARM64_PGTABLE_LEVELS > 2
371 
372 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
373 
374 #define pud_none(pud)		(!pud_val(pud))
375 #define pud_bad(pud)		(!(pud_val(pud) & 2))
376 #define pud_present(pud)	(pud_val(pud))
377 
378 static inline void set_pud(pud_t *pudp, pud_t pud)
379 {
380 	*pudp = pud;
381 	dsb(ishst);
382 	isb();
383 }
384 
385 static inline void pud_clear(pud_t *pudp)
386 {
387 	set_pud(pudp, __pud(0));
388 }
389 
390 static inline pmd_t *pud_page_vaddr(pud_t pud)
391 {
392 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
393 }
394 
395 /* Find an entry in the second-level page table. */
396 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
397 
398 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
399 {
400 	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
401 }
402 
403 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
404 
405 #endif	/* CONFIG_ARM64_PGTABLE_LEVELS > 2 */
406 
407 #if CONFIG_ARM64_PGTABLE_LEVELS > 3
408 
409 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
410 
411 #define pgd_none(pgd)		(!pgd_val(pgd))
412 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
413 #define pgd_present(pgd)	(pgd_val(pgd))
414 
415 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
416 {
417 	*pgdp = pgd;
418 	dsb(ishst);
419 }
420 
421 static inline void pgd_clear(pgd_t *pgdp)
422 {
423 	set_pgd(pgdp, __pgd(0));
424 }
425 
426 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
427 {
428 	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
429 }
430 
431 /* Find an entry in the frst-level page table. */
432 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
433 
434 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
435 {
436 	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
437 }
438 
439 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
440 
441 #endif  /* CONFIG_ARM64_PGTABLE_LEVELS > 3 */
442 
443 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
444 
445 /* to find an entry in a page-table-directory */
446 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
447 
448 #define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))
449 
450 /* to find an entry in a kernel page-table-directory */
451 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
452 
453 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
454 {
455 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
456 			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
457 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
458 	return pte;
459 }
460 
461 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
462 {
463 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
464 }
465 
466 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
467 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
468 
469 /*
470  * Encode and decode a swap entry:
471  *	bits 0-1:	present (must be zero)
472  *	bit  2:		PTE_FILE
473  *	bits 3-8:	swap type
474  *	bits 9-57:	swap offset
475  */
476 #define __SWP_TYPE_SHIFT	3
477 #define __SWP_TYPE_BITS		6
478 #define __SWP_OFFSET_BITS	49
479 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
480 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
481 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
482 
483 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
484 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
485 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
486 
487 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
488 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
489 
490 /*
491  * Ensure that there are not more swap files than can be encoded in the kernel
492  * PTEs.
493  */
494 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
495 
496 /*
497  * Encode and decode a file entry:
498  *	bits 0-1:	present (must be zero)
499  *	bit  2:		PTE_FILE
500  *	bits 3-57:	file offset / PAGE_SIZE
501  */
502 #define pte_file(pte)		(pte_val(pte) & PTE_FILE)
503 #define pte_to_pgoff(x)		(pte_val(x) >> 3)
504 #define pgoff_to_pte(x)		__pte(((x) << 3) | PTE_FILE)
505 
506 #define PTE_FILE_MAX_BITS	55
507 
508 extern int kern_addr_valid(unsigned long addr);
509 
510 #include <asm-generic/pgtable.h>
511 
512 #define pgtable_cache_init() do { } while (0)
513 
514 #endif /* !__ASSEMBLY__ */
515 
516 #endif /* __ASM_PGTABLE_H */
517