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Linux kernel mirror (for testing)
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linux
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 <asm/pgtable-nommu.h>
20
21#else
22
23#define __ARCH_USE_5LEVEL_HACK
24#include <asm-generic/pgtable-nopud.h>
25#include <asm/memory.h>
26#include <asm/pgtable-hwdef.h>
27
28
29#include <asm/tlbflush.h>
30
31#ifdef CONFIG_ARM_LPAE
32#include <asm/pgtable-3level.h>
33#else
34#include <asm/pgtable-2level.h>
35#endif
36
37/*
38 * Just any arbitrary offset to the start of the vmalloc VM area: the
39 * current 8MB value just means that there will be a 8MB "hole" after the
40 * physical memory until the kernel virtual memory starts. That means that
41 * any out-of-bounds memory accesses will hopefully be caught.
42 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
43 * area for the same reason. ;)
44 */
45#define VMALLOC_OFFSET (8*1024*1024)
46#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
47#define VMALLOC_END 0xff800000UL
48
49#define LIBRARY_TEXT_START 0x0c000000
50
51#ifndef __ASSEMBLY__
52extern void __pte_error(const char *file, int line, pte_t);
53extern void __pmd_error(const char *file, int line, pmd_t);
54extern void __pgd_error(const char *file, int line, pgd_t);
55
56#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
57#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
58#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
59
60/*
61 * This is the lowest virtual address we can permit any user space
62 * mapping to be mapped at. This is particularly important for
63 * non-high vector CPUs.
64 */
65#define FIRST_USER_ADDRESS (PAGE_SIZE * 2)
66
67/*
68 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
69 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
70 * page shared between user and kernel).
71 */
72#ifdef CONFIG_ARM_LPAE
73#define USER_PGTABLES_CEILING TASK_SIZE
74#endif
75
76/*
77 * The pgprot_* and protection_map entries will be fixed up in runtime
78 * to include the cachable and bufferable bits based on memory policy,
79 * as well as any architecture dependent bits like global/ASID and SMP
80 * shared mapping bits.
81 */
82#define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
83
84extern pgprot_t pgprot_user;
85extern pgprot_t pgprot_kernel;
86extern pgprot_t pgprot_hyp_device;
87extern pgprot_t pgprot_s2;
88extern pgprot_t pgprot_s2_device;
89
90#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
91
92#define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
93#define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
94#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
95#define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
96#define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
97#define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
98#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
99#define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
100#define PAGE_KERNEL_EXEC pgprot_kernel
101#define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_XN)
102#define PAGE_HYP_EXEC _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY)
103#define PAGE_HYP_RO _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY | L_PTE_XN)
104#define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
105#define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY | L_PTE_XN)
106#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY | L_PTE_XN)
107
108#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
109#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
110#define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
111#define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
112#define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
113#define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
114#define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
115
116#define __pgprot_modify(prot,mask,bits) \
117 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
118
119#define pgprot_noncached(prot) \
120 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
121
122#define pgprot_writecombine(prot) \
123 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
124
125#define pgprot_stronglyordered(prot) \
126 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
127
128#define pgprot_device(prot) \
129 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN)
130
131#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
132#define pgprot_dmacoherent(prot) \
133 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
134#define __HAVE_PHYS_MEM_ACCESS_PROT
135struct file;
136extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
137 unsigned long size, pgprot_t vma_prot);
138#else
139#define pgprot_dmacoherent(prot) \
140 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
141#endif
142
143#endif /* __ASSEMBLY__ */
144
145/*
146 * The table below defines the page protection levels that we insert into our
147 * Linux page table version. These get translated into the best that the
148 * architecture can perform. Note that on most ARM hardware:
149 * 1) We cannot do execute protection
150 * 2) If we could do execute protection, then read is implied
151 * 3) write implies read permissions
152 */
153#define __P000 __PAGE_NONE
154#define __P001 __PAGE_READONLY
155#define __P010 __PAGE_COPY
156#define __P011 __PAGE_COPY
157#define __P100 __PAGE_READONLY_EXEC
158#define __P101 __PAGE_READONLY_EXEC
159#define __P110 __PAGE_COPY_EXEC
160#define __P111 __PAGE_COPY_EXEC
161
162#define __S000 __PAGE_NONE
163#define __S001 __PAGE_READONLY
164#define __S010 __PAGE_SHARED
165#define __S011 __PAGE_SHARED
166#define __S100 __PAGE_READONLY_EXEC
167#define __S101 __PAGE_READONLY_EXEC
168#define __S110 __PAGE_SHARED_EXEC
169#define __S111 __PAGE_SHARED_EXEC
170
171#ifndef __ASSEMBLY__
172/*
173 * ZERO_PAGE is a global shared page that is always zero: used
174 * for zero-mapped memory areas etc..
175 */
176extern struct page *empty_zero_page;
177#define ZERO_PAGE(vaddr) (empty_zero_page)
178
179
180extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
181
182/* to find an entry in a page-table-directory */
183#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
184
185#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
186
187/* to find an entry in a kernel page-table-directory */
188#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
189
190#define pmd_none(pmd) (!pmd_val(pmd))
191
192static inline pte_t *pmd_page_vaddr(pmd_t pmd)
193{
194 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
195}
196
197#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
198
199#ifndef CONFIG_HIGHPTE
200#define __pte_map(pmd) pmd_page_vaddr(*(pmd))
201#define __pte_unmap(pte) do { } while (0)
202#else
203#define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd)))
204#define __pte_unmap(pte) kunmap_atomic(pte)
205#endif
206
207#define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
208
209#define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr))
210
211#define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr))
212#define pte_unmap(pte) __pte_unmap(pte)
213
214#define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
215#define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
216
217#define pte_page(pte) pfn_to_page(pte_pfn(pte))
218#define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
219
220#define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
221
222#define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \
223 : !!(pte_val(pte) & (val)))
224#define pte_isclear(pte, val) (!(pte_val(pte) & (val)))
225
226#define pte_none(pte) (!pte_val(pte))
227#define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT))
228#define pte_valid(pte) (pte_isset((pte), L_PTE_VALID))
229#define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
230#define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY))
231#define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY))
232#define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG))
233#define pte_exec(pte) (pte_isclear((pte), L_PTE_XN))
234
235#define pte_valid_user(pte) \
236 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
237
238static inline bool pte_access_permitted(pte_t pte, bool write)
239{
240 pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
241 pteval_t needed = mask;
242
243 if (write)
244 mask |= L_PTE_RDONLY;
245
246 return (pte_val(pte) & mask) == needed;
247}
248#define pte_access_permitted pte_access_permitted
249
250#if __LINUX_ARM_ARCH__ < 6
251static inline void __sync_icache_dcache(pte_t pteval)
252{
253}
254#else
255extern void __sync_icache_dcache(pte_t pteval);
256#endif
257
258static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
259 pte_t *ptep, pte_t pteval)
260{
261 unsigned long ext = 0;
262
263 if (addr < TASK_SIZE && pte_valid_user(pteval)) {
264 if (!pte_special(pteval))
265 __sync_icache_dcache(pteval);
266 ext |= PTE_EXT_NG;
267 }
268
269 set_pte_ext(ptep, pteval, ext);
270}
271
272static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
273{
274 pte_val(pte) &= ~pgprot_val(prot);
275 return pte;
276}
277
278static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
279{
280 pte_val(pte) |= pgprot_val(prot);
281 return pte;
282}
283
284static inline pte_t pte_wrprotect(pte_t pte)
285{
286 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
287}
288
289static inline pte_t pte_mkwrite(pte_t pte)
290{
291 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY));
292}
293
294static inline pte_t pte_mkclean(pte_t pte)
295{
296 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY));
297}
298
299static inline pte_t pte_mkdirty(pte_t pte)
300{
301 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY));
302}
303
304static inline pte_t pte_mkold(pte_t pte)
305{
306 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG));
307}
308
309static inline pte_t pte_mkyoung(pte_t pte)
310{
311 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG));
312}
313
314static inline pte_t pte_mkexec(pte_t pte)
315{
316 return clear_pte_bit(pte, __pgprot(L_PTE_XN));
317}
318
319static inline pte_t pte_mknexec(pte_t pte)
320{
321 return set_pte_bit(pte, __pgprot(L_PTE_XN));
322}
323
324static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
325{
326 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
327 L_PTE_NONE | L_PTE_VALID;
328 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
329 return pte;
330}
331
332/*
333 * Encode and decode a swap entry. Swap entries are stored in the Linux
334 * page tables as follows:
335 *
336 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
337 * 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
338 * <--------------- offset ------------------------> < type -> 0 0
339 *
340 * This gives us up to 31 swap files and 128GB per swap file. Note that
341 * the offset field is always non-zero.
342 */
343#define __SWP_TYPE_SHIFT 2
344#define __SWP_TYPE_BITS 5
345#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
346#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
347
348#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
349#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
350#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
351
352#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
353#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
354
355/*
356 * It is an error for the kernel to have more swap files than we can
357 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
358 * is increased beyond what we presently support.
359 */
360#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
361
362/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
363/* FIXME: this is not correct */
364#define kern_addr_valid(addr) (1)
365
366#include <asm-generic/pgtable.h>
367
368/*
369 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
370 */
371#define HAVE_ARCH_UNMAPPED_AREA
372#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
373
374#define pgtable_cache_init() do { } while (0)
375
376#endif /* !__ASSEMBLY__ */
377
378#endif /* CONFIG_MMU */
379
380#endif /* _ASMARM_PGTABLE_H */