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1 | /* | |
2 | * arch/arm/include/asm/pgtable.h | |
3 | * | |
4 | * Copyright (C) 1995-2002 Russell King | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #ifndef _ASMARM_PGTABLE_H | |
11 | #define _ASMARM_PGTABLE_H | |
12 | ||
13 | #include <linux/const.h> | |
14 | #include <asm-generic/4level-fixup.h> | |
15 | #include <asm/proc-fns.h> | |
16 | ||
17 | #ifndef CONFIG_MMU | |
18 | ||
19 | #include "pgtable-nommu.h" | |
20 | ||
21 | #else | |
22 | ||
23 | #include <asm/memory.h> | |
24 | #include <mach/vmalloc.h> | |
25 | #include <asm/pgtable-hwdef.h> | |
26 | ||
27 | /* | |
28 | * Just any arbitrary offset to the start of the vmalloc VM area: the | |
29 | * current 8MB value just means that there will be a 8MB "hole" after the | |
30 | * physical memory until the kernel virtual memory starts. That means that | |
31 | * any out-of-bounds memory accesses will hopefully be caught. | |
32 | * The vmalloc() routines leaves a hole of 4kB between each vmalloced | |
33 | * area for the same reason. ;) | |
34 | * | |
35 | * Note that platforms may override VMALLOC_START, but they must provide | |
36 | * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space, | |
37 | * which may not overlap IO space. | |
38 | */ | |
39 | #ifndef VMALLOC_START | |
40 | #define VMALLOC_OFFSET (8*1024*1024) | |
41 | #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) | |
42 | #endif | |
43 | ||
44 | /* | |
45 | * Hardware-wise, we have a two level page table structure, where the first | |
46 | * level has 4096 entries, and the second level has 256 entries. Each entry | |
47 | * is one 32-bit word. Most of the bits in the second level entry are used | |
48 | * by hardware, and there aren't any "accessed" and "dirty" bits. | |
49 | * | |
50 | * Linux on the other hand has a three level page table structure, which can | |
51 | * be wrapped to fit a two level page table structure easily - using the PGD | |
52 | * and PTE only. However, Linux also expects one "PTE" table per page, and | |
53 | * at least a "dirty" bit. | |
54 | * | |
55 | * Therefore, we tweak the implementation slightly - we tell Linux that we | |
56 | * have 2048 entries in the first level, each of which is 8 bytes (iow, two | |
57 | * hardware pointers to the second level.) The second level contains two | |
58 | * hardware PTE tables arranged contiguously, preceded by Linux versions | |
59 | * which contain the state information Linux needs. We, therefore, end up | |
60 | * with 512 entries in the "PTE" level. | |
61 | * | |
62 | * This leads to the page tables having the following layout: | |
63 | * | |
64 | * pgd pte | |
65 | * | | | |
66 | * +--------+ | |
67 | * | | +------------+ +0 | |
68 | * +- - - - + | Linux pt 0 | | |
69 | * | | +------------+ +1024 | |
70 | * +--------+ +0 | Linux pt 1 | | |
71 | * | |-----> +------------+ +2048 | |
72 | * +- - - - + +4 | h/w pt 0 | | |
73 | * | |-----> +------------+ +3072 | |
74 | * +--------+ +8 | h/w pt 1 | | |
75 | * | | +------------+ +4096 | |
76 | * | |
77 | * See L_PTE_xxx below for definitions of bits in the "Linux pt", and | |
78 | * PTE_xxx for definitions of bits appearing in the "h/w pt". | |
79 | * | |
80 | * PMD_xxx definitions refer to bits in the first level page table. | |
81 | * | |
82 | * The "dirty" bit is emulated by only granting hardware write permission | |
83 | * iff the page is marked "writable" and "dirty" in the Linux PTE. This | |
84 | * means that a write to a clean page will cause a permission fault, and | |
85 | * the Linux MM layer will mark the page dirty via handle_pte_fault(). | |
86 | * For the hardware to notice the permission change, the TLB entry must | |
87 | * be flushed, and ptep_set_access_flags() does that for us. | |
88 | * | |
89 | * The "accessed" or "young" bit is emulated by a similar method; we only | |
90 | * allow accesses to the page if the "young" bit is set. Accesses to the | |
91 | * page will cause a fault, and handle_pte_fault() will set the young bit | |
92 | * for us as long as the page is marked present in the corresponding Linux | |
93 | * PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is | |
94 | * up to date. | |
95 | * | |
96 | * However, when the "young" bit is cleared, we deny access to the page | |
97 | * by clearing the hardware PTE. Currently Linux does not flush the TLB | |
98 | * for us in this case, which means the TLB will retain the transation | |
99 | * until either the TLB entry is evicted under pressure, or a context | |
100 | * switch which changes the user space mapping occurs. | |
101 | */ | |
102 | #define PTRS_PER_PTE 512 | |
103 | #define PTRS_PER_PMD 1 | |
104 | #define PTRS_PER_PGD 2048 | |
105 | ||
106 | #define PTE_HWTABLE_PTRS (PTRS_PER_PTE) | |
107 | #define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t)) | |
108 | #define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32)) | |
109 | ||
110 | /* | |
111 | * PMD_SHIFT determines the size of the area a second-level page table can map | |
112 | * PGDIR_SHIFT determines what a third-level page table entry can map | |
113 | */ | |
114 | #define PMD_SHIFT 21 | |
115 | #define PGDIR_SHIFT 21 | |
116 | ||
117 | #define LIBRARY_TEXT_START 0x0c000000 | |
118 | ||
119 | #ifndef __ASSEMBLY__ | |
120 | extern void __pte_error(const char *file, int line, pte_t); | |
121 | extern void __pmd_error(const char *file, int line, pmd_t); | |
122 | extern void __pgd_error(const char *file, int line, pgd_t); | |
123 | ||
124 | #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte) | |
125 | #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd) | |
126 | #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd) | |
127 | #endif /* !__ASSEMBLY__ */ | |
128 | ||
129 | #define PMD_SIZE (1UL << PMD_SHIFT) | |
130 | #define PMD_MASK (~(PMD_SIZE-1)) | |
131 | #define PGDIR_SIZE (1UL << PGDIR_SHIFT) | |
132 | #define PGDIR_MASK (~(PGDIR_SIZE-1)) | |
133 | ||
134 | /* | |
135 | * This is the lowest virtual address we can permit any user space | |
136 | * mapping to be mapped at. This is particularly important for | |
137 | * non-high vector CPUs. | |
138 | */ | |
139 | #define FIRST_USER_ADDRESS PAGE_SIZE | |
140 | ||
141 | #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) | |
142 | ||
143 | /* | |
144 | * section address mask and size definitions. | |
145 | */ | |
146 | #define SECTION_SHIFT 20 | |
147 | #define SECTION_SIZE (1UL << SECTION_SHIFT) | |
148 | #define SECTION_MASK (~(SECTION_SIZE-1)) | |
149 | ||
150 | /* | |
151 | * ARMv6 supersection address mask and size definitions. | |
152 | */ | |
153 | #define SUPERSECTION_SHIFT 24 | |
154 | #define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT) | |
155 | #define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1)) | |
156 | ||
157 | /* | |
158 | * "Linux" PTE definitions. | |
159 | * | |
160 | * We keep two sets of PTEs - the hardware and the linux version. | |
161 | * This allows greater flexibility in the way we map the Linux bits | |
162 | * onto the hardware tables, and allows us to have YOUNG and DIRTY | |
163 | * bits. | |
164 | * | |
165 | * The PTE table pointer refers to the hardware entries; the "Linux" | |
166 | * entries are stored 1024 bytes below. | |
167 | */ | |
168 | #define L_PTE_PRESENT (_AT(pteval_t, 1) << 0) | |
169 | #define L_PTE_YOUNG (_AT(pteval_t, 1) << 1) | |
170 | #define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */ | |
171 | #define L_PTE_DIRTY (_AT(pteval_t, 1) << 6) | |
172 | #define L_PTE_RDONLY (_AT(pteval_t, 1) << 7) | |
173 | #define L_PTE_USER (_AT(pteval_t, 1) << 8) | |
174 | #define L_PTE_XN (_AT(pteval_t, 1) << 9) | |
175 | #define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */ | |
176 | ||
177 | /* | |
178 | * These are the memory types, defined to be compatible with | |
179 | * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB | |
180 | */ | |
181 | #define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */ | |
182 | #define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */ | |
183 | #define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */ | |
184 | #define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */ | |
185 | #define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */ | |
186 | #define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */ | |
187 | #define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */ | |
188 | #define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */ | |
189 | #define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */ | |
190 | #define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */ | |
191 | #define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2) | |
192 | ||
193 | #ifndef __ASSEMBLY__ | |
194 | ||
195 | /* | |
196 | * The pgprot_* and protection_map entries will be fixed up in runtime | |
197 | * to include the cachable and bufferable bits based on memory policy, | |
198 | * as well as any architecture dependent bits like global/ASID and SMP | |
199 | * shared mapping bits. | |
200 | */ | |
201 | #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG | |
202 | ||
203 | extern pgprot_t pgprot_user; | |
204 | extern pgprot_t pgprot_kernel; | |
205 | ||
206 | #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) | |
207 | ||
208 | #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY) | |
209 | #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN) | |
210 | #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER) | |
211 | #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) | |
212 | #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) | |
213 | #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) | |
214 | #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) | |
215 | #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) | |
216 | #define PAGE_KERNEL_EXEC pgprot_kernel | |
217 | ||
218 | #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN) | |
219 | #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) | |
220 | #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER) | |
221 | #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) | |
222 | #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) | |
223 | #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) | |
224 | #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) | |
225 | ||
226 | #define __pgprot_modify(prot,mask,bits) \ | |
227 | __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) | |
228 | ||
229 | #define pgprot_noncached(prot) \ | |
230 | __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) | |
231 | ||
232 | #define pgprot_writecombine(prot) \ | |
233 | __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) | |
234 | ||
235 | #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE | |
236 | #define pgprot_dmacoherent(prot) \ | |
237 | __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) | |
238 | #define __HAVE_PHYS_MEM_ACCESS_PROT | |
239 | struct file; | |
240 | extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, | |
241 | unsigned long size, pgprot_t vma_prot); | |
242 | #else | |
243 | #define pgprot_dmacoherent(prot) \ | |
244 | __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN) | |
245 | #endif | |
246 | ||
247 | #endif /* __ASSEMBLY__ */ | |
248 | ||
249 | /* | |
250 | * The table below defines the page protection levels that we insert into our | |
251 | * Linux page table version. These get translated into the best that the | |
252 | * architecture can perform. Note that on most ARM hardware: | |
253 | * 1) We cannot do execute protection | |
254 | * 2) If we could do execute protection, then read is implied | |
255 | * 3) write implies read permissions | |
256 | */ | |
257 | #define __P000 __PAGE_NONE | |
258 | #define __P001 __PAGE_READONLY | |
259 | #define __P010 __PAGE_COPY | |
260 | #define __P011 __PAGE_COPY | |
261 | #define __P100 __PAGE_READONLY_EXEC | |
262 | #define __P101 __PAGE_READONLY_EXEC | |
263 | #define __P110 __PAGE_COPY_EXEC | |
264 | #define __P111 __PAGE_COPY_EXEC | |
265 | ||
266 | #define __S000 __PAGE_NONE | |
267 | #define __S001 __PAGE_READONLY | |
268 | #define __S010 __PAGE_SHARED | |
269 | #define __S011 __PAGE_SHARED | |
270 | #define __S100 __PAGE_READONLY_EXEC | |
271 | #define __S101 __PAGE_READONLY_EXEC | |
272 | #define __S110 __PAGE_SHARED_EXEC | |
273 | #define __S111 __PAGE_SHARED_EXEC | |
274 | ||
275 | #ifndef __ASSEMBLY__ | |
276 | /* | |
277 | * ZERO_PAGE is a global shared page that is always zero: used | |
278 | * for zero-mapped memory areas etc.. | |
279 | */ | |
280 | extern struct page *empty_zero_page; | |
281 | #define ZERO_PAGE(vaddr) (empty_zero_page) | |
282 | ||
283 | ||
284 | extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; | |
285 | ||
286 | /* to find an entry in a page-table-directory */ | |
287 | #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) | |
288 | ||
289 | #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) | |
290 | ||
291 | /* to find an entry in a kernel page-table-directory */ | |
292 | #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) | |
293 | ||
294 | /* | |
295 | * The "pgd_xxx()" functions here are trivial for a folded two-level | |
296 | * setup: the pgd is never bad, and a pmd always exists (as it's folded | |
297 | * into the pgd entry) | |
298 | */ | |
299 | #define pgd_none(pgd) (0) | |
300 | #define pgd_bad(pgd) (0) | |
301 | #define pgd_present(pgd) (1) | |
302 | #define pgd_clear(pgdp) do { } while (0) | |
303 | #define set_pgd(pgd,pgdp) do { } while (0) | |
304 | #define set_pud(pud,pudp) do { } while (0) | |
305 | ||
306 | ||
307 | /* Find an entry in the second-level page table.. */ | |
308 | #define pmd_offset(dir, addr) ((pmd_t *)(dir)) | |
309 | ||
310 | #define pmd_none(pmd) (!pmd_val(pmd)) | |
311 | #define pmd_present(pmd) (pmd_val(pmd)) | |
312 | #define pmd_bad(pmd) (pmd_val(pmd) & 2) | |
313 | ||
314 | #define copy_pmd(pmdpd,pmdps) \ | |
315 | do { \ | |
316 | pmdpd[0] = pmdps[0]; \ | |
317 | pmdpd[1] = pmdps[1]; \ | |
318 | flush_pmd_entry(pmdpd); \ | |
319 | } while (0) | |
320 | ||
321 | #define pmd_clear(pmdp) \ | |
322 | do { \ | |
323 | pmdp[0] = __pmd(0); \ | |
324 | pmdp[1] = __pmd(0); \ | |
325 | clean_pmd_entry(pmdp); \ | |
326 | } while (0) | |
327 | ||
328 | static inline pte_t *pmd_page_vaddr(pmd_t pmd) | |
329 | { | |
330 | return __va(pmd_val(pmd) & PAGE_MASK); | |
331 | } | |
332 | ||
333 | #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) | |
334 | ||
335 | /* we don't need complex calculations here as the pmd is folded into the pgd */ | |
336 | #define pmd_addr_end(addr,end) (end) | |
337 | ||
338 | ||
339 | #ifndef CONFIG_HIGHPTE | |
340 | #define __pte_map(pmd) pmd_page_vaddr(*(pmd)) | |
341 | #define __pte_unmap(pte) do { } while (0) | |
342 | #else | |
343 | #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd))) | |
344 | #define __pte_unmap(pte) kunmap_atomic(pte) | |
345 | #endif | |
346 | ||
347 | #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) | |
348 | ||
349 | #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr)) | |
350 | ||
351 | #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr)) | |
352 | #define pte_unmap(pte) __pte_unmap(pte) | |
353 | ||
354 | #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) | |
355 | #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) | |
356 | ||
357 | #define pte_page(pte) pfn_to_page(pte_pfn(pte)) | |
358 | #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot) | |
359 | ||
360 | #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext) | |
361 | #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0) | |
362 | ||
363 | #if __LINUX_ARM_ARCH__ < 6 | |
364 | static inline void __sync_icache_dcache(pte_t pteval) | |
365 | { | |
366 | } | |
367 | #else | |
368 | extern void __sync_icache_dcache(pte_t pteval); | |
369 | #endif | |
370 | ||
371 | static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, | |
372 | pte_t *ptep, pte_t pteval) | |
373 | { | |
374 | if (addr >= TASK_SIZE) | |
375 | set_pte_ext(ptep, pteval, 0); | |
376 | else { | |
377 | __sync_icache_dcache(pteval); | |
378 | set_pte_ext(ptep, pteval, PTE_EXT_NG); | |
379 | } | |
380 | } | |
381 | ||
382 | #define pte_none(pte) (!pte_val(pte)) | |
383 | #define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT) | |
384 | #define pte_write(pte) (!(pte_val(pte) & L_PTE_RDONLY)) | |
385 | #define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY) | |
386 | #define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG) | |
387 | #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN)) | |
388 | #define pte_special(pte) (0) | |
389 | ||
390 | #define pte_present_user(pte) \ | |
391 | ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \ | |
392 | (L_PTE_PRESENT | L_PTE_USER)) | |
393 | ||
394 | #define PTE_BIT_FUNC(fn,op) \ | |
395 | static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } | |
396 | ||
397 | PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY); | |
398 | PTE_BIT_FUNC(mkwrite, &= ~L_PTE_RDONLY); | |
399 | PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY); | |
400 | PTE_BIT_FUNC(mkdirty, |= L_PTE_DIRTY); | |
401 | PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG); | |
402 | PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG); | |
403 | ||
404 | static inline pte_t pte_mkspecial(pte_t pte) { return pte; } | |
405 | ||
406 | static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) | |
407 | { | |
408 | const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER; | |
409 | pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); | |
410 | return pte; | |
411 | } | |
412 | ||
413 | /* | |
414 | * Encode and decode a swap entry. Swap entries are stored in the Linux | |
415 | * page tables as follows: | |
416 | * | |
417 | * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 | |
418 | * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 | |
419 | * <--------------- offset --------------------> <- type --> 0 0 0 | |
420 | * | |
421 | * This gives us up to 63 swap files and 32GB per swap file. Note that | |
422 | * the offset field is always non-zero. | |
423 | */ | |
424 | #define __SWP_TYPE_SHIFT 3 | |
425 | #define __SWP_TYPE_BITS 6 | |
426 | #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) | |
427 | #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) | |
428 | ||
429 | #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) | |
430 | #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) | |
431 | #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) | |
432 | ||
433 | #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) | |
434 | #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) | |
435 | ||
436 | /* | |
437 | * It is an error for the kernel to have more swap files than we can | |
438 | * encode in the PTEs. This ensures that we know when MAX_SWAPFILES | |
439 | * is increased beyond what we presently support. | |
440 | */ | |
441 | #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) | |
442 | ||
443 | /* | |
444 | * Encode and decode a file entry. File entries are stored in the Linux | |
445 | * page tables as follows: | |
446 | * | |
447 | * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 | |
448 | * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 | |
449 | * <----------------------- offset ------------------------> 1 0 0 | |
450 | */ | |
451 | #define pte_file(pte) (pte_val(pte) & L_PTE_FILE) | |
452 | #define pte_to_pgoff(x) (pte_val(x) >> 3) | |
453 | #define pgoff_to_pte(x) __pte(((x) << 3) | L_PTE_FILE) | |
454 | ||
455 | #define PTE_FILE_MAX_BITS 29 | |
456 | ||
457 | /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ | |
458 | /* FIXME: this is not correct */ | |
459 | #define kern_addr_valid(addr) (1) | |
460 | ||
461 | #include <asm-generic/pgtable.h> | |
462 | ||
463 | /* | |
464 | * We provide our own arch_get_unmapped_area to cope with VIPT caches. | |
465 | */ | |
466 | #define HAVE_ARCH_UNMAPPED_AREA | |
467 | ||
468 | /* | |
469 | * remap a physical page `pfn' of size `size' with page protection `prot' | |
470 | * into virtual address `from' | |
471 | */ | |
472 | #define io_remap_pfn_range(vma,from,pfn,size,prot) \ | |
473 | remap_pfn_range(vma, from, pfn, size, prot) | |
474 | ||
475 | #define pgtable_cache_init() do { } while (0) | |
476 | ||
477 | void identity_mapping_add(pgd_t *, unsigned long, unsigned long); | |
478 | void identity_mapping_del(pgd_t *, unsigned long, unsigned long); | |
479 | ||
480 | #endif /* !__ASSEMBLY__ */ | |
481 | ||
482 | #endif /* CONFIG_MMU */ | |
483 | ||
484 | #endif /* _ASMARM_PGTABLE_H */ |