xref: /openbmc/linux/arch/arm64/include/asm/pgtable.h (revision 4f3db074)
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 VA space 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			((struct page *)(VMALLOC_END + SZ_64K))
47 
48 #define FIRST_USER_ADDRESS	0UL
49 
50 #ifndef __ASSEMBLY__
51 extern void __pte_error(const char *file, int line, unsigned long val);
52 extern void __pmd_error(const char *file, int line, unsigned long val);
53 extern void __pud_error(const char *file, int line, unsigned long val);
54 extern void __pgd_error(const char *file, int line, unsigned long val);
55 
56 #ifdef CONFIG_SMP
57 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
58 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
59 #else
60 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF)
61 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF)
62 #endif
63 
64 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
65 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
66 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
67 
68 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
69 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
70 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
71 
72 #define _PAGE_DEFAULT		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
73 
74 #define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
75 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
76 
77 #define PAGE_HYP		__pgprot(_PAGE_DEFAULT | PTE_HYP)
78 #define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
79 
80 #define PAGE_S2			__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
81 #define PAGE_S2_DEVICE		__pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_UXN)
82 
83 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
84 #define PAGE_SHARED		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
85 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
86 #define PAGE_COPY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
87 #define PAGE_COPY_EXEC		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
88 #define PAGE_READONLY		__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
89 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
90 
91 #define __P000  PAGE_NONE
92 #define __P001  PAGE_READONLY
93 #define __P010  PAGE_COPY
94 #define __P011  PAGE_COPY
95 #define __P100  PAGE_READONLY_EXEC
96 #define __P101  PAGE_READONLY_EXEC
97 #define __P110  PAGE_COPY_EXEC
98 #define __P111  PAGE_COPY_EXEC
99 
100 #define __S000  PAGE_NONE
101 #define __S001  PAGE_READONLY
102 #define __S010  PAGE_SHARED
103 #define __S011  PAGE_SHARED
104 #define __S100  PAGE_READONLY_EXEC
105 #define __S101  PAGE_READONLY_EXEC
106 #define __S110  PAGE_SHARED_EXEC
107 #define __S111  PAGE_SHARED_EXEC
108 
109 /*
110  * ZERO_PAGE is a global shared page that is always zero: used
111  * for zero-mapped memory areas etc..
112  */
113 extern struct page *empty_zero_page;
114 #define ZERO_PAGE(vaddr)	(empty_zero_page)
115 
116 #define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
117 
118 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
119 
120 #define pfn_pte(pfn,prot)	(__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
121 
122 #define pte_none(pte)		(!pte_val(pte))
123 #define pte_clear(mm,addr,ptep)	set_pte(ptep, __pte(0))
124 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
125 
126 /* Find an entry in the third-level page table. */
127 #define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
128 
129 #define pte_offset_kernel(dir,addr)	(pmd_page_vaddr(*(dir)) + pte_index(addr))
130 
131 #define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
132 #define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
133 #define pte_unmap(pte)			do { } while (0)
134 #define pte_unmap_nested(pte)		do { } while (0)
135 
136 /*
137  * The following only work if pte_present(). Undefined behaviour otherwise.
138  */
139 #define pte_present(pte)	(!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
140 #define pte_dirty(pte)		(!!(pte_val(pte) & PTE_DIRTY))
141 #define pte_young(pte)		(!!(pte_val(pte) & PTE_AF))
142 #define pte_special(pte)	(!!(pte_val(pte) & PTE_SPECIAL))
143 #define pte_write(pte)		(!!(pte_val(pte) & PTE_WRITE))
144 #define pte_exec(pte)		(!(pte_val(pte) & PTE_UXN))
145 
146 #define pte_valid_user(pte) \
147 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
148 #define pte_valid_not_user(pte) \
149 	((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
150 
151 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
152 {
153 	pte_val(pte) &= ~pgprot_val(prot);
154 	return pte;
155 }
156 
157 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
158 {
159 	pte_val(pte) |= pgprot_val(prot);
160 	return pte;
161 }
162 
163 static inline pte_t pte_wrprotect(pte_t pte)
164 {
165 	return clear_pte_bit(pte, __pgprot(PTE_WRITE));
166 }
167 
168 static inline pte_t pte_mkwrite(pte_t pte)
169 {
170 	return set_pte_bit(pte, __pgprot(PTE_WRITE));
171 }
172 
173 static inline pte_t pte_mkclean(pte_t pte)
174 {
175 	return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
176 }
177 
178 static inline pte_t pte_mkdirty(pte_t pte)
179 {
180 	return set_pte_bit(pte, __pgprot(PTE_DIRTY));
181 }
182 
183 static inline pte_t pte_mkold(pte_t pte)
184 {
185 	return clear_pte_bit(pte, __pgprot(PTE_AF));
186 }
187 
188 static inline pte_t pte_mkyoung(pte_t pte)
189 {
190 	return set_pte_bit(pte, __pgprot(PTE_AF));
191 }
192 
193 static inline pte_t pte_mkspecial(pte_t pte)
194 {
195 	return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
196 }
197 
198 static inline void set_pte(pte_t *ptep, pte_t pte)
199 {
200 	*ptep = pte;
201 
202 	/*
203 	 * Only if the new pte is valid and kernel, otherwise TLB maintenance
204 	 * or update_mmu_cache() have the necessary barriers.
205 	 */
206 	if (pte_valid_not_user(pte)) {
207 		dsb(ishst);
208 		isb();
209 	}
210 }
211 
212 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
213 
214 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
215 			      pte_t *ptep, pte_t pte)
216 {
217 	if (pte_valid_user(pte)) {
218 		if (!pte_special(pte) && pte_exec(pte))
219 			__sync_icache_dcache(pte, addr);
220 		if (pte_dirty(pte) && pte_write(pte))
221 			pte_val(pte) &= ~PTE_RDONLY;
222 		else
223 			pte_val(pte) |= PTE_RDONLY;
224 	}
225 
226 	set_pte(ptep, pte);
227 }
228 
229 /*
230  * Huge pte definitions.
231  */
232 #define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
233 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
234 
235 /*
236  * Hugetlb definitions.
237  */
238 #define HUGE_MAX_HSTATE		2
239 #define HPAGE_SHIFT		PMD_SHIFT
240 #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
241 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
242 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
243 
244 #define __HAVE_ARCH_PTE_SPECIAL
245 
246 static inline pte_t pud_pte(pud_t pud)
247 {
248 	return __pte(pud_val(pud));
249 }
250 
251 static inline pmd_t pud_pmd(pud_t pud)
252 {
253 	return __pmd(pud_val(pud));
254 }
255 
256 static inline pte_t pmd_pte(pmd_t pmd)
257 {
258 	return __pte(pmd_val(pmd));
259 }
260 
261 static inline pmd_t pte_pmd(pte_t pte)
262 {
263 	return __pmd(pte_val(pte));
264 }
265 
266 static inline pgprot_t mk_sect_prot(pgprot_t prot)
267 {
268 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
269 }
270 
271 /*
272  * THP definitions.
273  */
274 
275 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
276 #define pmd_trans_huge(pmd)	(pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
277 #define pmd_trans_splitting(pmd)	pte_special(pmd_pte(pmd))
278 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
279 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
280 struct vm_area_struct;
281 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
282 			  pmd_t *pmdp);
283 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
284 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
285 
286 #define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
287 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
288 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
289 #define pmd_mksplitting(pmd)	pte_pmd(pte_mkspecial(pmd_pte(pmd)))
290 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
291 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
292 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
293 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
294 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
295 
296 #define __HAVE_ARCH_PMD_WRITE
297 #define pmd_write(pmd)		pte_write(pmd_pte(pmd))
298 
299 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
300 
301 #define pmd_pfn(pmd)		(((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
302 #define pfn_pmd(pfn,prot)	(__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
303 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
304 
305 #define pud_write(pud)		pte_write(pud_pte(pud))
306 #define pud_pfn(pud)		(((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
307 
308 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
309 
310 static inline int has_transparent_hugepage(void)
311 {
312 	return 1;
313 }
314 
315 #define __pgprot_modify(prot,mask,bits) \
316 	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
317 
318 /*
319  * Mark the prot value as uncacheable and unbufferable.
320  */
321 #define pgprot_noncached(prot) \
322 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
323 #define pgprot_writecombine(prot) \
324 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
325 #define pgprot_device(prot) \
326 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
327 #define __HAVE_PHYS_MEM_ACCESS_PROT
328 struct file;
329 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
330 				     unsigned long size, pgprot_t vma_prot);
331 
332 #define pmd_none(pmd)		(!pmd_val(pmd))
333 #define pmd_present(pmd)	(pmd_val(pmd))
334 
335 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
336 
337 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
338 				 PMD_TYPE_TABLE)
339 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
340 				 PMD_TYPE_SECT)
341 
342 #ifdef CONFIG_ARM64_64K_PAGES
343 #define pud_sect(pud)		(0)
344 #define pud_table(pud)		(1)
345 #else
346 #define pud_sect(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
347 				 PUD_TYPE_SECT)
348 #define pud_table(pud)		((pud_val(pud) & PUD_TYPE_MASK) == \
349 				 PUD_TYPE_TABLE)
350 #endif
351 
352 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
353 {
354 	*pmdp = pmd;
355 	dsb(ishst);
356 	isb();
357 }
358 
359 static inline void pmd_clear(pmd_t *pmdp)
360 {
361 	set_pmd(pmdp, __pmd(0));
362 }
363 
364 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
365 {
366 	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
367 }
368 
369 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
370 
371 /*
372  * Conversion functions: convert a page and protection to a page entry,
373  * and a page entry and page directory to the page they refer to.
374  */
375 #define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
376 
377 #if CONFIG_PGTABLE_LEVELS > 2
378 
379 #define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd_val(pmd))
380 
381 #define pud_none(pud)		(!pud_val(pud))
382 #define pud_bad(pud)		(!(pud_val(pud) & 2))
383 #define pud_present(pud)	(pud_val(pud))
384 
385 static inline void set_pud(pud_t *pudp, pud_t pud)
386 {
387 	*pudp = pud;
388 	dsb(ishst);
389 	isb();
390 }
391 
392 static inline void pud_clear(pud_t *pudp)
393 {
394 	set_pud(pudp, __pud(0));
395 }
396 
397 static inline pmd_t *pud_page_vaddr(pud_t pud)
398 {
399 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
400 }
401 
402 /* Find an entry in the second-level page table. */
403 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
404 
405 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
406 {
407 	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
408 }
409 
410 #define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
411 
412 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
413 
414 #if CONFIG_PGTABLE_LEVELS > 3
415 
416 #define pud_ERROR(pud)		__pud_error(__FILE__, __LINE__, pud_val(pud))
417 
418 #define pgd_none(pgd)		(!pgd_val(pgd))
419 #define pgd_bad(pgd)		(!(pgd_val(pgd) & 2))
420 #define pgd_present(pgd)	(pgd_val(pgd))
421 
422 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
423 {
424 	*pgdp = pgd;
425 	dsb(ishst);
426 }
427 
428 static inline void pgd_clear(pgd_t *pgdp)
429 {
430 	set_pgd(pgdp, __pgd(0));
431 }
432 
433 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
434 {
435 	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
436 }
437 
438 /* Find an entry in the frst-level page table. */
439 #define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
440 
441 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
442 {
443 	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
444 }
445 
446 #define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
447 
448 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
449 
450 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
451 
452 /* to find an entry in a page-table-directory */
453 #define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
454 
455 #define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))
456 
457 /* to find an entry in a kernel page-table-directory */
458 #define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
459 
460 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
461 {
462 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
463 			      PTE_PROT_NONE | PTE_WRITE | PTE_TYPE_MASK;
464 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
465 	return pte;
466 }
467 
468 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
469 {
470 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
471 }
472 
473 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
474 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
475 
476 /*
477  * Encode and decode a swap entry:
478  *	bits 0-1:	present (must be zero)
479  *	bits 2-7:	swap type
480  *	bits 8-57:	swap offset
481  */
482 #define __SWP_TYPE_SHIFT	2
483 #define __SWP_TYPE_BITS		6
484 #define __SWP_OFFSET_BITS	50
485 #define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
486 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
487 #define __SWP_OFFSET_MASK	((1UL << __SWP_OFFSET_BITS) - 1)
488 
489 #define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
490 #define __swp_offset(x)		(((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
491 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
492 
493 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
494 #define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
495 
496 /*
497  * Ensure that there are not more swap files than can be encoded in the kernel
498  * PTEs.
499  */
500 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
501 
502 extern int kern_addr_valid(unsigned long addr);
503 
504 #include <asm-generic/pgtable.h>
505 
506 #define pgtable_cache_init() do { } while (0)
507 
508 #endif /* !__ASSEMBLY__ */
509 
510 #endif /* __ASM_PGTABLE_H */
511