1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * arch/arm/include/asm/pgtable.h
4 *
5 * Copyright (C) 1995-2002 Russell King
6 */
7 #ifndef _ASMARM_PGTABLE_H
8 #define _ASMARM_PGTABLE_H
9
10 #include <linux/const.h>
11 #include <asm/proc-fns.h>
12
13 #ifndef __ASSEMBLY__
14 /*
15 * ZERO_PAGE is a global shared page that is always zero: used
16 * for zero-mapped memory areas etc..
17 */
18 extern struct page *empty_zero_page;
19 #define ZERO_PAGE(vaddr) (empty_zero_page)
20 #endif
21
22 #ifndef CONFIG_MMU
23
24 #include <asm-generic/pgtable-nopud.h>
25 #include <asm/pgtable-nommu.h>
26
27 #else
28
29 #include <asm-generic/pgtable-nopud.h>
30 #include <asm/memory.h>
31 #include <asm/pgtable-hwdef.h>
32
33
34 #include <asm/tlbflush.h>
35
36 #ifdef CONFIG_ARM_LPAE
37 #include <asm/pgtable-3level.h>
38 #else
39 #include <asm/pgtable-2level.h>
40 #endif
41
42 /*
43 * Just any arbitrary offset to the start of the vmalloc VM area: the
44 * current 8MB value just means that there will be a 8MB "hole" after the
45 * physical memory until the kernel virtual memory starts. That means that
46 * any out-of-bounds memory accesses will hopefully be caught.
47 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
48 * area for the same reason. ;)
49 */
50 #define VMALLOC_OFFSET (8*1024*1024)
51 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
52 #define VMALLOC_END 0xff800000UL
53 #define VMALLOC_DEFAULT_BASE (VMALLOC_END - (240 << 20) - VMALLOC_OFFSET)
54
55 #define LIBRARY_TEXT_START 0x0c000000
56
57 #ifndef __ASSEMBLY__
58 extern void __pte_error(const char *file, int line, pte_t);
59 extern void __pmd_error(const char *file, int line, pmd_t);
60 extern void __pgd_error(const char *file, int line, pgd_t);
61
62 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
63 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
64 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
65
66 /*
67 * This is the lowest virtual address we can permit any user space
68 * mapping to be mapped at. This is particularly important for
69 * non-high vector CPUs.
70 */
71 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2)
72
73 /*
74 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
75 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
76 * page shared between user and kernel).
77 */
78 #ifdef CONFIG_ARM_LPAE
79 #define USER_PGTABLES_CEILING TASK_SIZE
80 #endif
81
82 /*
83 * The pgprot_* and protection_map entries will be fixed up in runtime
84 * to include the cachable and bufferable bits based on memory policy,
85 * as well as any architecture dependent bits like global/ASID and SMP
86 * shared mapping bits.
87 */
88 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
89
90 extern pgprot_t pgprot_user;
91 extern pgprot_t pgprot_kernel;
92
93 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
94
95 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
96 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
97 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
98 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
99 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
100 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
101 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
102 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
103 #define PAGE_KERNEL_EXEC pgprot_kernel
104
105 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
106 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
107 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
108 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
109 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
110 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
111 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
112
113 #define __pgprot_modify(prot,mask,bits) \
114 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
115
116 #define pgprot_noncached(prot) \
117 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
118
119 #define pgprot_writecombine(prot) \
120 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
121
122 #define pgprot_stronglyordered(prot) \
123 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
124
125 #define pgprot_device(prot) \
126 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN)
127
128 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
129 #define pgprot_dmacoherent(prot) \
130 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
131 #define __HAVE_PHYS_MEM_ACCESS_PROT
132 struct file;
133 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
134 unsigned long size, pgprot_t vma_prot);
135 #else
136 #define pgprot_dmacoherent(prot) \
137 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
138 #endif
139
140 #endif /* __ASSEMBLY__ */
141
142 /*
143 * The table below defines the page protection levels that we insert into our
144 * Linux page table version. These get translated into the best that the
145 * architecture can perform. Note that on most ARM hardware:
146 * 1) We cannot do execute protection
147 * 2) If we could do execute protection, then read is implied
148 * 3) write implies read permissions
149 */
150 #define __P000 __PAGE_NONE
151 #define __P001 __PAGE_READONLY
152 #define __P010 __PAGE_COPY
153 #define __P011 __PAGE_COPY
154 #define __P100 __PAGE_READONLY_EXEC
155 #define __P101 __PAGE_READONLY_EXEC
156 #define __P110 __PAGE_COPY_EXEC
157 #define __P111 __PAGE_COPY_EXEC
158
159 #define __S000 __PAGE_NONE
160 #define __S001 __PAGE_READONLY
161 #define __S010 __PAGE_SHARED
162 #define __S011 __PAGE_SHARED
163 #define __S100 __PAGE_READONLY_EXEC
164 #define __S101 __PAGE_READONLY_EXEC
165 #define __S110 __PAGE_SHARED_EXEC
166 #define __S111 __PAGE_SHARED_EXEC
167
168 #ifndef __ASSEMBLY__
169
170 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
171
172 #define pmd_none(pmd) (!pmd_val(pmd))
173
pmd_page_vaddr(pmd_t pmd)174 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
175 {
176 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
177 }
178
179 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
180
181 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
182 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
183
184 #define pte_page(pte) pfn_to_page(pte_pfn(pte))
185 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
186
187 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
188
189 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \
190 : !!(pte_val(pte) & (val)))
191 #define pte_isclear(pte, val) (!(pte_val(pte) & (val)))
192
193 #define pte_none(pte) (!pte_val(pte))
194 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT))
195 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID))
196 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
197 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY))
198 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY))
199 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG))
200 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN))
201
202 #define pte_valid_user(pte) \
203 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
204
pte_access_permitted(pte_t pte,bool write)205 static inline bool pte_access_permitted(pte_t pte, bool write)
206 {
207 pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
208 pteval_t needed = mask;
209
210 if (write)
211 mask |= L_PTE_RDONLY;
212
213 return (pte_val(pte) & mask) == needed;
214 }
215 #define pte_access_permitted pte_access_permitted
216
217 #if __LINUX_ARM_ARCH__ < 6
__sync_icache_dcache(pte_t pteval)218 static inline void __sync_icache_dcache(pte_t pteval)
219 {
220 }
221 #else
222 extern void __sync_icache_dcache(pte_t pteval);
223 #endif
224
225 void set_pte_at(struct mm_struct *mm, unsigned long addr,
226 pte_t *ptep, pte_t pteval);
227
clear_pte_bit(pte_t pte,pgprot_t prot)228 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
229 {
230 pte_val(pte) &= ~pgprot_val(prot);
231 return pte;
232 }
233
set_pte_bit(pte_t pte,pgprot_t prot)234 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
235 {
236 pte_val(pte) |= pgprot_val(prot);
237 return pte;
238 }
239
pte_wrprotect(pte_t pte)240 static inline pte_t pte_wrprotect(pte_t pte)
241 {
242 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
243 }
244
pte_mkwrite(pte_t pte)245 static inline pte_t pte_mkwrite(pte_t pte)
246 {
247 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY));
248 }
249
pte_mkclean(pte_t pte)250 static inline pte_t pte_mkclean(pte_t pte)
251 {
252 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY));
253 }
254
pte_mkdirty(pte_t pte)255 static inline pte_t pte_mkdirty(pte_t pte)
256 {
257 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY));
258 }
259
pte_mkold(pte_t pte)260 static inline pte_t pte_mkold(pte_t pte)
261 {
262 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG));
263 }
264
pte_mkyoung(pte_t pte)265 static inline pte_t pte_mkyoung(pte_t pte)
266 {
267 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG));
268 }
269
pte_mkexec(pte_t pte)270 static inline pte_t pte_mkexec(pte_t pte)
271 {
272 return clear_pte_bit(pte, __pgprot(L_PTE_XN));
273 }
274
pte_mknexec(pte_t pte)275 static inline pte_t pte_mknexec(pte_t pte)
276 {
277 return set_pte_bit(pte, __pgprot(L_PTE_XN));
278 }
279
pte_modify(pte_t pte,pgprot_t newprot)280 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
281 {
282 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
283 L_PTE_NONE | L_PTE_VALID;
284 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
285 return pte;
286 }
287
288 /*
289 * Encode and decode a swap entry. Swap entries are stored in the Linux
290 * page tables as follows:
291 *
292 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
293 * 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
294 * <--------------- offset ------------------------> < type -> 0 0
295 *
296 * This gives us up to 31 swap files and 128GB per swap file. Note that
297 * the offset field is always non-zero.
298 */
299 #define __SWP_TYPE_SHIFT 2
300 #define __SWP_TYPE_BITS 5
301 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
302 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
303
304 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
305 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
306 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
307
308 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
309 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
310
311 /*
312 * It is an error for the kernel to have more swap files than we can
313 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
314 * is increased beyond what we presently support.
315 */
316 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
317
318 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
319 /* FIXME: this is not correct */
320 #define kern_addr_valid(addr) (1)
321
322 /*
323 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
324 */
325 #define HAVE_ARCH_UNMAPPED_AREA
326 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
327
328 #endif /* !__ASSEMBLY__ */
329
330 #endif /* CONFIG_MMU */
331
332 #endif /* _ASMARM_PGTABLE_H */
333