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/page.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
54 #define LIBRARY_TEXT_START 0x0c000000
55
56 #ifndef __ASSEMBLY__
57 extern void __pte_error(const char *file, int line, pte_t);
58 extern void __pmd_error(const char *file, int line, pmd_t);
59 extern void __pgd_error(const char *file, int line, pgd_t);
60
61 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
62 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
63 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
64
65 /*
66 * This is the lowest virtual address we can permit any user space
67 * mapping to be mapped at. This is particularly important for
68 * non-high vector CPUs.
69 */
70 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2)
71
72 /*
73 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
74 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
75 * page shared between user and kernel).
76 */
77 #ifdef CONFIG_ARM_LPAE
78 #define USER_PGTABLES_CEILING TASK_SIZE
79 #endif
80
81 /*
82 * The pgprot_* and protection_map entries will be fixed up in runtime
83 * to include the cachable and bufferable bits based on memory policy,
84 * as well as any architecture dependent bits like global/ASID and SMP
85 * shared mapping bits.
86 */
87 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
88
89 extern pgprot_t pgprot_user;
90 extern pgprot_t pgprot_kernel;
91
92 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
93
94 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
95 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
96 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
97 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
98 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
99 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
100 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
101 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
102 #define PAGE_KERNEL_EXEC pgprot_kernel
103
104 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
105 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
106 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
107 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
108 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
109 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
110 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
111
112 #define __pgprot_modify(prot,mask,bits) \
113 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
114
115 #define pgprot_noncached(prot) \
116 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
117
118 #define pgprot_writecombine(prot) \
119 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
120
121 #define pgprot_stronglyordered(prot) \
122 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
123
124 #define pgprot_device(prot) \
125 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN)
126
127 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
128 #define pgprot_dmacoherent(prot) \
129 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
130 #define __HAVE_PHYS_MEM_ACCESS_PROT
131 struct file;
132 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
133 unsigned long size, pgprot_t vma_prot);
134 #else
135 #define pgprot_dmacoherent(prot) \
136 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
137 #endif
138
139 #endif /* __ASSEMBLY__ */
140
141 /*
142 * The table below defines the page protection levels that we insert into our
143 * Linux page table version. These get translated into the best that the
144 * architecture can perform. Note that on most ARM hardware:
145 * 1) We cannot do execute protection
146 * 2) If we could do execute protection, then read is implied
147 * 3) write implies read permissions
148 */
149
150 #ifndef __ASSEMBLY__
151
152 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
153
154 #define pgdp_get(pgpd) READ_ONCE(*pgdp)
155
156 #define pud_page(pud) pmd_page(__pmd(pud_val(pud)))
157 #define pud_write(pud) pmd_write(__pmd(pud_val(pud)))
158
159 #define pmd_none(pmd) (!pmd_val(pmd))
160
161 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
162 {
163 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
164 }
165
166 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
167
168 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
169 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
170
171 #define pte_page(pte) pfn_to_page(pte_pfn(pte))
172 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
173
174 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
175
176 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \
177 : !!(pte_val(pte) & (val)))
178 #define pte_isclear(pte, val) (!(pte_val(pte) & (val)))
179
180 #define pte_none(pte) (!pte_val(pte))
181 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT))
182 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID))
183 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
184 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY))
185 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY))
186 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG))
187 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN))
188
189 #define pte_valid_user(pte) \
190 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
191
192 static inline bool pte_access_permitted(pte_t pte, bool write)
193 {
194 pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
195 pteval_t needed = mask;
196
197 if (write)
198 mask |= L_PTE_RDONLY;
199
200 return (pte_val(pte) & mask) == needed;
201 }
202 #define pte_access_permitted pte_access_permitted
203
204 #if __LINUX_ARM_ARCH__ < 6
205 static inline void __sync_icache_dcache(pte_t pteval)
206 {
207 }
208 #else
209 extern void __sync_icache_dcache(pte_t pteval);
210 #endif
211
212 #define PFN_PTE_SHIFT PAGE_SHIFT
213
214 void set_ptes(struct mm_struct *mm, unsigned long addr,
215 pte_t *ptep, pte_t pteval, unsigned int nr);
216 #define set_ptes set_ptes
217
218 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
219 {
220 pte_val(pte) &= ~pgprot_val(prot);
221 return pte;
222 }
223
224 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
225 {
226 pte_val(pte) |= pgprot_val(prot);
227 return pte;
228 }
229
230 static inline pte_t pte_wrprotect(pte_t pte)
231 {
232 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
233 }
234
235 static inline pte_t pte_mkwrite_novma(pte_t pte)
236 {
237 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY));
238 }
239
240 static inline pte_t pte_mkclean(pte_t pte)
241 {
242 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY));
243 }
244
245 static inline pte_t pte_mkdirty(pte_t pte)
246 {
247 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY));
248 }
249
250 static inline pte_t pte_mkold(pte_t pte)
251 {
252 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG));
253 }
254
255 static inline pte_t pte_mkyoung(pte_t pte)
256 {
257 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG));
258 }
259
260 static inline pte_t pte_mkexec(pte_t pte)
261 {
262 return clear_pte_bit(pte, __pgprot(L_PTE_XN));
263 }
264
265 static inline pte_t pte_mknexec(pte_t pte)
266 {
267 return set_pte_bit(pte, __pgprot(L_PTE_XN));
268 }
269
270 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
271 {
272 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
273 L_PTE_NONE | L_PTE_VALID;
274 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
275 return pte;
276 }
277
278 /*
279 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
280 * are !pte_none() && !pte_present().
281 *
282 * Format of swap PTEs:
283 *
284 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
285 * 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
286 * <------------------- offset ------------------> E < type -> 0 0
287 *
288 * E is the exclusive marker that is not stored in swap entries.
289 *
290 * This gives us up to 31 swap files and 64GB per swap file. Note that
291 * the offset field is always non-zero.
292 */
293 #define __SWP_TYPE_SHIFT 2
294 #define __SWP_TYPE_BITS 5
295 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
296 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT + 1)
297
298 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
299 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
300 #define __swp_entry(type, offset) ((swp_entry_t) { (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \
301 ((offset) << __SWP_OFFSET_SHIFT) })
302
303 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
304 #define __swp_entry_to_pte(swp) __pte((swp).val)
305
306 static inline int pte_swp_exclusive(pte_t pte)
307 {
308 return pte_isset(pte, L_PTE_SWP_EXCLUSIVE);
309 }
310
311 static inline pte_t pte_swp_mkexclusive(pte_t pte)
312 {
313 return set_pte_bit(pte, __pgprot(L_PTE_SWP_EXCLUSIVE));
314 }
315
316 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
317 {
318 return clear_pte_bit(pte, __pgprot(L_PTE_SWP_EXCLUSIVE));
319 }
320
321 /*
322 * It is an error for the kernel to have more swap files than we can
323 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
324 * is increased beyond what we presently support.
325 */
326 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
327
328 /*
329 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
330 */
331 #define HAVE_ARCH_UNMAPPED_AREA
332 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
333
334 #endif /* !__ASSEMBLY__ */
335
336 #endif /* CONFIG_MMU */
337
338 #endif /* _ASMARM_PGTABLE_H */
339
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