summaryrefslogtreecommitdiff
path: root/arch/arm/include/asm/pgtable.h
blob: ef48a55e9af83bd56c5f4ab21f684a1876b0ae44 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  arch/arm/include/asm/pgtable.h
 *
 *  Copyright (C) 1995-2002 Russell King
 */
#ifndef _ASMARM_PGTABLE_H
#define _ASMARM_PGTABLE_H

#include <linux/const.h>
#include <asm/proc-fns.h>

#ifndef __ASSEMBLY__
/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern struct page *empty_zero_page;
#define ZERO_PAGE(vaddr)	(empty_zero_page)
#endif

#ifndef CONFIG_MMU

#include <asm-generic/pgtable-nopud.h>
#include <asm/pgtable-nommu.h>

#else

#include <asm-generic/pgtable-nopud.h>
#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>


#include <asm/tlbflush.h>

#ifdef CONFIG_ARM_LPAE
#include <asm/pgtable-3level.h>
#else
#include <asm/pgtable-2level.h>
#endif

/*
 * Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 8MB value just means that there will be a 8MB "hole" after the
 * physical memory until the kernel virtual memory starts.  That means that
 * any out-of-bounds memory accesses will hopefully be caught.
 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 * area for the same reason. ;)
 */
#define VMALLOC_OFFSET		(8*1024*1024)
#define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
#define VMALLOC_END		0xff800000UL

#define LIBRARY_TEXT_START	0x0c000000

#ifndef __ASSEMBLY__
extern void __pte_error(const char *file, int line, pte_t);
extern void __pmd_error(const char *file, int line, pmd_t);
extern void __pgd_error(const char *file, int line, pgd_t);

#define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte)
#define pmd_ERROR(pmd)		__pmd_error(__FILE__, __LINE__, pmd)
#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd)

/*
 * This is the lowest virtual address we can permit any user space
 * mapping to be mapped at.  This is particularly important for
 * non-high vector CPUs.
 */
#define FIRST_USER_ADDRESS	(PAGE_SIZE * 2)

/*
 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
 * page shared between user and kernel).
 */
#ifdef CONFIG_ARM_LPAE
#define USER_PGTABLES_CEILING	TASK_SIZE
#endif

/*
 * The pgprot_* and protection_map entries will be fixed up in runtime
 * to include the cachable and bufferable bits based on memory policy,
 * as well as any architecture dependent bits like global/ASID and SMP
 * shared mapping bits.
 */
#define _L_PTE_DEFAULT	L_PTE_PRESENT | L_PTE_YOUNG

extern pgprot_t		pgprot_user;
extern pgprot_t		pgprot_kernel;

#define _MOD_PROT(p, b)	__pgprot(pgprot_val(p) | (b))

#define PAGE_NONE		_MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
#define PAGE_SHARED		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
#define PAGE_SHARED_EXEC	_MOD_PROT(pgprot_user, L_PTE_USER)
#define PAGE_COPY		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define PAGE_COPY_EXEC		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#define PAGE_READONLY		_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define PAGE_READONLY_EXEC	_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#define PAGE_KERNEL		_MOD_PROT(pgprot_kernel, L_PTE_XN)
#define PAGE_KERNEL_EXEC	pgprot_kernel

#define __PAGE_NONE		__pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
#define __PAGE_SHARED		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
#define __PAGE_SHARED_EXEC	__pgprot(_L_PTE_DEFAULT | L_PTE_USER)
#define __PAGE_COPY		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define __PAGE_COPY_EXEC	__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
#define __PAGE_READONLY		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
#define __PAGE_READONLY_EXEC	__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)

#define __pgprot_modify(prot,mask,bits)		\
	__pgprot((pgprot_val(prot) & ~(mask)) | (bits))

#define pgprot_noncached(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)

#define pgprot_writecombine(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)

#define pgprot_stronglyordered(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)

#define pgprot_device(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN)

#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#define pgprot_dmacoherent(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
				     unsigned long size, pgprot_t vma_prot);
#else
#define pgprot_dmacoherent(prot) \
	__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
#endif

#endif /* __ASSEMBLY__ */

/*
 * The table below defines the page protection levels that we insert into our
 * Linux page table version.  These get translated into the best that the
 * architecture can perform.  Note that on most ARM hardware:
 *  1) We cannot do execute protection
 *  2) If we could do execute protection, then read is implied
 *  3) write implies read permissions
 */

#ifndef __ASSEMBLY__

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

#define pud_page(pud)		pmd_page(__pmd(pud_val(pud)))
#define pud_write(pud)		pmd_write(__pmd(pud_val(pud)))

#define pmd_none(pmd)		(!pmd_val(pmd))

static inline pte_t *pmd_page_vaddr(pmd_t pmd)
{
	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
}

#define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))

#define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
#define pfn_pte(pfn,prot)	__pte(__pfn_to_phys(pfn) | pgprot_val(prot))

#define pte_page(pte)		pfn_to_page(pte_pfn(pte))
#define mk_pte(page,prot)	pfn_pte(page_to_pfn(page), prot)

#define pte_clear(mm,addr,ptep)	set_pte_ext(ptep, __pte(0), 0)

#define pte_isset(pte, val)	((u32)(val) == (val) ? pte_val(pte) & (val) \
						: !!(pte_val(pte) & (val)))
#define pte_isclear(pte, val)	(!(pte_val(pte) & (val)))

#define pte_none(pte)		(!pte_val(pte))
#define pte_present(pte)	(pte_isset((pte), L_PTE_PRESENT))
#define pte_valid(pte)		(pte_isset((pte), L_PTE_VALID))
#define pte_accessible(mm, pte)	(mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
#define pte_write(pte)		(pte_isclear((pte), L_PTE_RDONLY))
#define pte_dirty(pte)		(pte_isset((pte), L_PTE_DIRTY))
#define pte_young(pte)		(pte_isset((pte), L_PTE_YOUNG))
#define pte_exec(pte)		(pte_isclear((pte), L_PTE_XN))

#define pte_valid_user(pte)	\
	(pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))

static inline bool pte_access_permitted(pte_t pte, bool write)
{
	pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
	pteval_t needed = mask;

	if (write)
		mask |= L_PTE_RDONLY;

	return (pte_val(pte) & mask) == needed;
}
#define pte_access_permitted pte_access_permitted

#if __LINUX_ARM_ARCH__ < 6
static inline void __sync_icache_dcache(pte_t pteval)
{
}
#else
extern void __sync_icache_dcache(pte_t pteval);
#endif

void set_pte_at(struct mm_struct *mm, unsigned long addr,
		      pte_t *ptep, pte_t pteval);

static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
{
	pte_val(pte) &= ~pgprot_val(prot);
	return pte;
}

static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
{
	pte_val(pte) |= pgprot_val(prot);
	return pte;
}

static inline pte_t pte_wrprotect(pte_t pte)
{
	return set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
}

static inline pte_t pte_mkwrite(pte_t pte)
{
	return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY));
}

static inline pte_t pte_mkclean(pte_t pte)
{
	return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY));
}

static inline pte_t pte_mkdirty(pte_t pte)
{
	return set_pte_bit(pte, __pgprot(L_PTE_DIRTY));
}

static inline pte_t pte_mkold(pte_t pte)
{
	return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG));
}

static inline pte_t pte_mkyoung(pte_t pte)
{
	return set_pte_bit(pte, __pgprot(L_PTE_YOUNG));
}

static inline pte_t pte_mkexec(pte_t pte)
{
	return clear_pte_bit(pte, __pgprot(L_PTE_XN));
}

static inline pte_t pte_mknexec(pte_t pte)
{
	return set_pte_bit(pte, __pgprot(L_PTE_XN));
}

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
		L_PTE_NONE | L_PTE_VALID;
	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
	return pte;
}

/*
 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 * page tables as follows:
 *
 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 *   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
 *   <--------------- offset ------------------------> < type -> 0 0
 *
 * This gives us up to 31 swap files and 128GB per swap file.  Note that
 * the offset field is always non-zero.
 */
#define __SWP_TYPE_SHIFT	2
#define __SWP_TYPE_BITS		5
#define __SWP_TYPE_MASK		((1 << __SWP_TYPE_BITS) - 1)
#define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)

#define __swp_type(x)		(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
#define __swp_offset(x)		((x).val >> __SWP_OFFSET_SHIFT)
#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })

#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(swp)	__pte((swp).val | PTE_TYPE_FAULT)

/*
 * It is an error for the kernel to have more swap files than we can
 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 * is increased beyond what we presently support.
 */
#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)

/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
/* FIXME: this is not correct */
#define kern_addr_valid(addr)	(1)

/*
 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 */
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

#endif /* !__ASSEMBLY__ */

#endif /* CONFIG_MMU */

#endif /* _ASMARM_PGTABLE_H */