1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 * Copyright 2003 PathScale, Inc.
5 * Derived from include/asm-i386/pgtable.h
6 */
7
8 #ifndef __UM_PGTABLE_H
9 #define __UM_PGTABLE_H
10
11 #include <asm/fixmap.h>
12
13 #define _PAGE_PRESENT 0x001
14 #define _PAGE_NEWPAGE 0x002
15 #define _PAGE_NEWPROT 0x004
16 #define _PAGE_RW 0x020
17 #define _PAGE_USER 0x040
18 #define _PAGE_ACCESSED 0x080
19 #define _PAGE_DIRTY 0x100
20 /* If _PAGE_PRESENT is clear, we use these: */
21 #define _PAGE_PROTNONE 0x010 /* if the user mapped it with PROT_NONE;
22 pte_present gives true */
23
24 /* We borrow bit 10 to store the exclusive marker in swap PTEs. */
25 #define _PAGE_SWP_EXCLUSIVE 0x400
26
27 #ifdef CONFIG_3_LEVEL_PGTABLES
28 #include <asm/pgtable-3level.h>
29 #else
30 #include <asm/pgtable-2level.h>
31 #endif
32
33 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
34
35 /* zero page used for uninitialized stuff */
36 extern unsigned long *empty_zero_page;
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
46 extern unsigned long end_iomem;
47
48 #define VMALLOC_OFFSET (__va_space)
49 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
50 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
51 #define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
52 #define MODULES_VADDR VMALLOC_START
53 #define MODULES_END VMALLOC_END
54 #define MODULES_LEN (MODULES_VADDR - MODULES_END)
55
56 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
57 #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
58 #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
59 #define __PAGE_KERNEL_EXEC \
60 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
61 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
62 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
63 #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
64 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
65 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
66 #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
67
68 /*
69 * The i386 can't do page protection for execute, and considers that the same
70 * are read.
71 * Also, write permissions imply read permissions. This is the closest we can
72 * get..
73 */
74
75 /*
76 * ZERO_PAGE is a global shared page that is always zero: used
77 * for zero-mapped memory areas etc..
78 */
79 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
80
81 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
82
83 #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
84 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
85
86 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
87 #define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
88
89 #define pmd_newpage(x) (pmd_val(x) & _PAGE_NEWPAGE)
90 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
91
92 #define pud_newpage(x) (pud_val(x) & _PAGE_NEWPAGE)
93 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
94
95 #define p4d_newpage(x) (p4d_val(x) & _PAGE_NEWPAGE)
96 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
97
98 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
99 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
100
101 #define pte_page(x) pfn_to_page(pte_pfn(x))
102
103 #define pte_present(x) pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
104
105 /*
106 * =================================
107 * Flags checking section.
108 * =================================
109 */
110
pte_none(pte_t pte)111 static inline int pte_none(pte_t pte)
112 {
113 return pte_is_zero(pte);
114 }
115
116 /*
117 * The following only work if pte_present() is true.
118 * Undefined behaviour if not..
119 */
pte_read(pte_t pte)120 static inline int pte_read(pte_t pte)
121 {
122 return((pte_get_bits(pte, _PAGE_USER)) &&
123 !(pte_get_bits(pte, _PAGE_PROTNONE)));
124 }
125
pte_exec(pte_t pte)126 static inline int pte_exec(pte_t pte){
127 return((pte_get_bits(pte, _PAGE_USER)) &&
128 !(pte_get_bits(pte, _PAGE_PROTNONE)));
129 }
130
pte_write(pte_t pte)131 static inline int pte_write(pte_t pte)
132 {
133 return((pte_get_bits(pte, _PAGE_RW)) &&
134 !(pte_get_bits(pte, _PAGE_PROTNONE)));
135 }
136
pte_dirty(pte_t pte)137 static inline int pte_dirty(pte_t pte)
138 {
139 return pte_get_bits(pte, _PAGE_DIRTY);
140 }
141
pte_young(pte_t pte)142 static inline int pte_young(pte_t pte)
143 {
144 return pte_get_bits(pte, _PAGE_ACCESSED);
145 }
146
pte_newpage(pte_t pte)147 static inline int pte_newpage(pte_t pte)
148 {
149 return pte_get_bits(pte, _PAGE_NEWPAGE);
150 }
151
pte_newprot(pte_t pte)152 static inline int pte_newprot(pte_t pte)
153 {
154 return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
155 }
156
157 /*
158 * =================================
159 * Flags setting section.
160 * =================================
161 */
162
pte_mknewprot(pte_t pte)163 static inline pte_t pte_mknewprot(pte_t pte)
164 {
165 pte_set_bits(pte, _PAGE_NEWPROT);
166 return(pte);
167 }
168
pte_mkclean(pte_t pte)169 static inline pte_t pte_mkclean(pte_t pte)
170 {
171 pte_clear_bits(pte, _PAGE_DIRTY);
172 return(pte);
173 }
174
pte_mkold(pte_t pte)175 static inline pte_t pte_mkold(pte_t pte)
176 {
177 pte_clear_bits(pte, _PAGE_ACCESSED);
178 return(pte);
179 }
180
pte_wrprotect(pte_t pte)181 static inline pte_t pte_wrprotect(pte_t pte)
182 {
183 if (likely(pte_get_bits(pte, _PAGE_RW)))
184 pte_clear_bits(pte, _PAGE_RW);
185 else
186 return pte;
187 return(pte_mknewprot(pte));
188 }
189
pte_mkread(pte_t pte)190 static inline pte_t pte_mkread(pte_t pte)
191 {
192 if (unlikely(pte_get_bits(pte, _PAGE_USER)))
193 return pte;
194 pte_set_bits(pte, _PAGE_USER);
195 return(pte_mknewprot(pte));
196 }
197
pte_mkdirty(pte_t pte)198 static inline pte_t pte_mkdirty(pte_t pte)
199 {
200 pte_set_bits(pte, _PAGE_DIRTY);
201 return(pte);
202 }
203
pte_mkyoung(pte_t pte)204 static inline pte_t pte_mkyoung(pte_t pte)
205 {
206 pte_set_bits(pte, _PAGE_ACCESSED);
207 return(pte);
208 }
209
pte_mkwrite_novma(pte_t pte)210 static inline pte_t pte_mkwrite_novma(pte_t pte)
211 {
212 if (unlikely(pte_get_bits(pte, _PAGE_RW)))
213 return pte;
214 pte_set_bits(pte, _PAGE_RW);
215 return(pte_mknewprot(pte));
216 }
217
pte_mkuptodate(pte_t pte)218 static inline pte_t pte_mkuptodate(pte_t pte)
219 {
220 pte_clear_bits(pte, _PAGE_NEWPAGE);
221 if(pte_present(pte))
222 pte_clear_bits(pte, _PAGE_NEWPROT);
223 return(pte);
224 }
225
pte_mknewpage(pte_t pte)226 static inline pte_t pte_mknewpage(pte_t pte)
227 {
228 pte_set_bits(pte, _PAGE_NEWPAGE);
229 return(pte);
230 }
231
set_pte(pte_t * pteptr,pte_t pteval)232 static inline void set_pte(pte_t *pteptr, pte_t pteval)
233 {
234 pte_copy(*pteptr, pteval);
235
236 /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
237 * fix_range knows to unmap it. _PAGE_NEWPROT is specific to
238 * mapped pages.
239 */
240
241 *pteptr = pte_mknewpage(*pteptr);
242 if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
243 }
244
245 #define PFN_PTE_SHIFT PAGE_SHIFT
246
247 #define __HAVE_ARCH_PTE_SAME
pte_same(pte_t pte_a,pte_t pte_b)248 static inline int pte_same(pte_t pte_a, pte_t pte_b)
249 {
250 return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
251 }
252
253 /*
254 * Conversion functions: convert a page and protection to a page entry,
255 * and a page entry and page directory to the page they refer to.
256 */
257
258 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
259 #define __virt_to_page(virt) phys_to_page(__pa(virt))
260 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
261 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
262
263 #define mk_pte(page, pgprot) \
264 ({ pte_t pte; \
265 \
266 pte_set_val(pte, page_to_phys(page), (pgprot)); \
267 if (pte_present(pte)) \
268 pte_mknewprot(pte_mknewpage(pte)); \
269 pte;})
270
pte_modify(pte_t pte,pgprot_t newprot)271 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
272 {
273 pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
274 return pte;
275 }
276
277 /*
278 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
279 *
280 * this macro returns the index of the entry in the pmd page which would
281 * control the given virtual address
282 */
283 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
284
285 struct mm_struct;
286 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
287
288 #define update_mmu_cache(vma,address,ptep) do {} while (0)
289 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
290
291 /*
292 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
293 * are !pte_none() && !pte_present().
294 *
295 * Format of swap PTEs:
296 *
297 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
298 * 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
299 * <--------------- offset ----------------> E < type -> 0 0 0 1 0
300 *
301 * E is the exclusive marker that is not stored in swap entries.
302 * _PAGE_NEWPAGE (bit 1) is always set to 1 in set_pte().
303 */
304 #define __swp_type(x) (((x).val >> 5) & 0x1f)
305 #define __swp_offset(x) ((x).val >> 11)
306
307 #define __swp_entry(type, offset) \
308 ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
309 #define __pte_to_swp_entry(pte) \
310 ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
311 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
312
pte_swp_exclusive(pte_t pte)313 static inline int pte_swp_exclusive(pte_t pte)
314 {
315 return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
316 }
317
pte_swp_mkexclusive(pte_t pte)318 static inline pte_t pte_swp_mkexclusive(pte_t pte)
319 {
320 pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
321 return pte;
322 }
323
pte_swp_clear_exclusive(pte_t pte)324 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
325 {
326 pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
327 return pte;
328 }
329
330 /* Clear a kernel PTE and flush it from the TLB */
331 #define kpte_clear_flush(ptep, vaddr) \
332 do { \
333 pte_clear(&init_mm, (vaddr), (ptep)); \
334 __flush_tlb_one((vaddr)); \
335 } while (0)
336
337 #endif
338