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/proc-fns.h>
15
16 #ifndef CONFIG_MMU
17
18 #include <asm-generic/4level-fixup.h>
19 #include "pgtable-nommu.h"
20
21 #else
22
23 #include <asm-generic/pgtable-nopud.h>
24 #include <asm/memory.h>
25 #include <asm/pgtable-hwdef.h>
26
27 #ifdef CONFIG_ARM_LPAE
28 #include <asm/pgtable-3level.h>
29 #else
30 #include <asm/pgtable-2level.h>
31 #endif
32
33 /*
34 * Just any arbitrary offset to the start of the vmalloc VM area: the
35 * current 8MB value just means that there will be a 8MB "hole" after the
36 * physical memory until the kernel virtual memory starts. That means that
37 * any out-of-bounds memory accesses will hopefully be caught.
38 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
39 * area for the same reason. ;)
40 */
41 #define VMALLOC_OFFSET (8*1024*1024)
42 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
43 #define VMALLOC_END 0xff000000UL
44
45 #define LIBRARY_TEXT_START 0x0c000000
46
47 #ifndef __ASSEMBLY__
48 extern void __pte_error(const char *file, int line, pte_t);
49 extern void __pmd_error(const char *file, int line, pmd_t);
50 extern void __pgd_error(const char *file, int line, pgd_t);
51
52 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
53 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
54 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
55
56 /*
57 * This is the lowest virtual address we can permit any user space
58 * mapping to be mapped at. This is particularly important for
59 * non-high vector CPUs.
60 */
61 #define FIRST_USER_ADDRESS PAGE_SIZE
62
63 /*
64 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
65 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
66 * page shared between user and kernel).
67 */
68 #ifdef CONFIG_ARM_LPAE
69 #define USER_PGTABLES_CEILING TASK_SIZE
70 #endif
71
72 /*
73 * The pgprot_* and protection_map entries will be fixed up in runtime
74 * to include the cachable and bufferable bits based on memory policy,
75 * as well as any architecture dependent bits like global/ASID and SMP
76 * shared mapping bits.
77 */
78 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
79
80 extern pgprot_t pgprot_user;
81 extern pgprot_t pgprot_kernel;
82
83 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
84
85 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
86 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
87 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
88 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
89 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
90 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
91 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
92 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
93 #define PAGE_KERNEL_EXEC pgprot_kernel
94
95 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
96 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
97 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
98 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
99 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
100 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
101 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
102
103 #define __pgprot_modify(prot,mask,bits) \
104 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
105
106 #define pgprot_noncached(prot) \
107 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
108
109 #define pgprot_writecombine(prot) \
110 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
111
112 #define pgprot_stronglyordered(prot) \
113 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
114
115 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
116 #define pgprot_dmacoherent(prot) \
117 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
118 #define __HAVE_PHYS_MEM_ACCESS_PROT
119 struct file;
120 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
121 unsigned long size, pgprot_t vma_prot);
122 #else
123 #define pgprot_dmacoherent(prot) \
124 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
125 #endif
126
127 #endif /* __ASSEMBLY__ */
128
129 /*
130 * The table below defines the page protection levels that we insert into our
131 * Linux page table version. These get translated into the best that the
132 * architecture can perform. Note that on most ARM hardware:
133 * 1) We cannot do execute protection
134 * 2) If we could do execute protection, then read is implied
135 * 3) write implies read permissions
136 */
137 #define __P000 __PAGE_NONE
138 #define __P001 __PAGE_READONLY
139 #define __P010 __PAGE_COPY
140 #define __P011 __PAGE_COPY
141 #define __P100 __PAGE_READONLY_EXEC
142 #define __P101 __PAGE_READONLY_EXEC
143 #define __P110 __PAGE_COPY_EXEC
144 #define __P111 __PAGE_COPY_EXEC
145
146 #define __S000 __PAGE_NONE
147 #define __S001 __PAGE_READONLY
148 #define __S010 __PAGE_SHARED
149 #define __S011 __PAGE_SHARED
150 #define __S100 __PAGE_READONLY_EXEC
151 #define __S101 __PAGE_READONLY_EXEC
152 #define __S110 __PAGE_SHARED_EXEC
153 #define __S111 __PAGE_SHARED_EXEC
154
155 #ifndef __ASSEMBLY__
156 /*
157 * ZERO_PAGE is a global shared page that is always zero: used
158 * for zero-mapped memory areas etc..
159 */
160 extern struct page *empty_zero_page;
161 #define ZERO_PAGE(vaddr) (empty_zero_page)
162
163
164 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
165
166 /* to find an entry in a page-table-directory */
167 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
168
169 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
170
171 /* to find an entry in a kernel page-table-directory */
172 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
173
174 #define pmd_none(pmd) (!pmd_val(pmd))
175 #define pmd_present(pmd) (pmd_val(pmd))
176
pmd_page_vaddr(pmd_t pmd)177 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
178 {
179 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
180 }
181
182 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
183
184 #ifndef CONFIG_HIGHPTE
185 #define __pte_map(pmd) pmd_page_vaddr(*(pmd))
186 #define __pte_unmap(pte) do { } while (0)
187 #else
188 #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd)))
189 #define __pte_unmap(pte) kunmap_atomic(pte)
190 #endif
191
192 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
193
194 #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr))
195
196 #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr))
197 #define pte_unmap(pte) __pte_unmap(pte)
198
199 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
200 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
201
202 #define pte_page(pte) pfn_to_page(pte_pfn(pte))
203 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
204
205 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
206
207 #define pte_none(pte) (!pte_val(pte))
208 #define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT)
209 #define pte_write(pte) (!(pte_val(pte) & L_PTE_RDONLY))
210 #define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY)
211 #define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG)
212 #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN))
213 #define pte_special(pte) (0)
214
215 #define pte_present_user(pte) \
216 ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
217 (L_PTE_PRESENT | L_PTE_USER))
218
219 #if __LINUX_ARM_ARCH__ < 6
__sync_icache_dcache(pte_t pteval)220 static inline void __sync_icache_dcache(pte_t pteval)
221 {
222 }
223 #else
224 extern void __sync_icache_dcache(pte_t pteval);
225 #endif
226
set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pteval)227 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
228 pte_t *ptep, pte_t pteval)
229 {
230 unsigned long ext = 0;
231
232 if (addr < TASK_SIZE && pte_present_user(pteval)) {
233 __sync_icache_dcache(pteval);
234 ext |= PTE_EXT_NG;
235 }
236
237 set_pte_ext(ptep, pteval, ext);
238 }
239
240 #define PTE_BIT_FUNC(fn,op) \
241 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
242
243 PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
244 PTE_BIT_FUNC(mkwrite, &= ~L_PTE_RDONLY);
245 PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY);
246 PTE_BIT_FUNC(mkdirty, |= L_PTE_DIRTY);
247 PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG);
248 PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG);
249
pte_mkspecial(pte_t pte)250 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
251
pte_modify(pte_t pte,pgprot_t newprot)252 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
253 {
254 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
255 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
256 return pte;
257 }
258
259 /*
260 * Encode and decode a swap entry. Swap entries are stored in the Linux
261 * page tables as follows:
262 *
263 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
264 * 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
265 * <--------------- offset ----------------------> < type -> 0 0 0
266 *
267 * This gives us up to 31 swap files and 64GB per swap file. Note that
268 * the offset field is always non-zero.
269 */
270 #define __SWP_TYPE_SHIFT 3
271 #define __SWP_TYPE_BITS 5
272 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
273 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
274
275 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
276 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
277 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
278
279 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
280 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
281
282 /*
283 * It is an error for the kernel to have more swap files than we can
284 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
285 * is increased beyond what we presently support.
286 */
287 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
288
289 /*
290 * Encode and decode a file entry. File entries are stored in the Linux
291 * page tables as follows:
292 *
293 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
294 * 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
295 * <----------------------- offset ------------------------> 1 0 0
296 */
297 #define pte_file(pte) (pte_val(pte) & L_PTE_FILE)
298 #define pte_to_pgoff(x) (pte_val(x) >> 3)
299 #define pgoff_to_pte(x) __pte(((x) << 3) | L_PTE_FILE)
300
301 #define PTE_FILE_MAX_BITS 29
302
303 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
304 /* FIXME: this is not correct */
305 #define kern_addr_valid(addr) (1)
306
307 #include <asm-generic/pgtable.h>
308
309 /*
310 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
311 */
312 #define HAVE_ARCH_UNMAPPED_AREA
313 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
314
315 /*
316 * remap a physical page `pfn' of size `size' with page protection `prot'
317 * into virtual address `from'
318 */
319 #define io_remap_pfn_range(vma,from,pfn,size,prot) \
320 remap_pfn_range(vma, from, pfn, size, prot)
321
322 #define pgtable_cache_init() do { } while (0)
323
324 #endif /* !__ASSEMBLY__ */
325
326 #endif /* CONFIG_MMU */
327
328 #endif /* _ASMARM_PGTABLE_H */
329