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_NEEDSYNC 0x002
15 #define _PAGE_RW 0x020
16 #define _PAGE_USER 0x040
17 #define _PAGE_ACCESSED 0x080
18 #define _PAGE_DIRTY 0x100
19 /* If _PAGE_PRESENT is clear, we use these: */
20 #define _PAGE_PROTNONE 0x010 /* if the user mapped it with PROT_NONE;
21 pte_present gives true */
22
23 /* We borrow bit 10 to store the exclusive marker in swap PTEs. */
24 #define _PAGE_SWP_EXCLUSIVE 0x400
25
26 #if CONFIG_PGTABLE_LEVELS == 4
27 #include <asm/pgtable-4level.h>
28 #elif CONFIG_PGTABLE_LEVELS == 2
29 #include <asm/pgtable-2level.h>
30 #else
31 #error "Unsupported number of page table levels"
32 #endif
33
34 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
35
36 /* zero page used for uninitialized stuff */
37 extern unsigned long *empty_zero_page;
38
39 /* Just any arbitrary offset to the start of the vmalloc VM area: the
40 * current 8MB value just means that there will be a 8MB "hole" after the
41 * physical memory until the kernel virtual memory starts. That means that
42 * any out-of-bounds memory accesses will hopefully be caught.
43 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
44 * area for the same reason. ;)
45 */
46
47 extern unsigned long end_iomem;
48
49 #define VMALLOC_OFFSET (__va_space)
50 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
51 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
52 #define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
53 #define MODULES_VADDR VMALLOC_START
54 #define MODULES_END VMALLOC_END
55 #define MODULES_LEN (MODULES_VADDR - MODULES_END)
56
57 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
58 #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
59 #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
60 #define __PAGE_KERNEL_EXEC \
61 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
62 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
63 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
64 #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
65 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
66 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
67 #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
68
69 /*
70 * The i386 can't do page protection for execute, and considers that the same
71 * are read.
72 * Also, write permissions imply read permissions. This is the closest we can
73 * get..
74 */
75
76 /*
77 * ZERO_PAGE is a global shared page that is always zero: used
78 * for zero-mapped memory areas etc..
79 */
80 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
81
82 #define pte_clear(mm, addr, xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEEDSYNC))
83
84 #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC))
85 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
86
87 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
88 #define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEEDSYNC; } while (0)
89
90 #define pmd_needsync(x) (pmd_val(x) & _PAGE_NEEDSYNC)
91 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEEDSYNC)
92
93 #define pud_needsync(x) (pud_val(x) & _PAGE_NEEDSYNC)
94 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEEDSYNC)
95
96 #define p4d_needsync(x) (p4d_val(x) & _PAGE_NEEDSYNC)
97 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEEDSYNC)
98
99 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
100 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
101
102 #define pte_page(x) pfn_to_page(pte_pfn(x))
103
104 #define pte_present(x) pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
105
106 /*
107 * =================================
108 * Flags checking section.
109 * =================================
110 */
111
pte_none(pte_t pte)112 static inline int pte_none(pte_t pte)
113 {
114 return pte_is_zero(pte);
115 }
116
117 /*
118 * The following only work if pte_present() is true.
119 * Undefined behaviour if not..
120 */
pte_read(pte_t pte)121 static inline int pte_read(pte_t pte)
122 {
123 return((pte_get_bits(pte, _PAGE_USER)) &&
124 !(pte_get_bits(pte, _PAGE_PROTNONE)));
125 }
126
pte_exec(pte_t pte)127 static inline int pte_exec(pte_t pte){
128 return((pte_get_bits(pte, _PAGE_USER)) &&
129 !(pte_get_bits(pte, _PAGE_PROTNONE)));
130 }
131
pte_write(pte_t pte)132 static inline int pte_write(pte_t pte)
133 {
134 return((pte_get_bits(pte, _PAGE_RW)) &&
135 !(pte_get_bits(pte, _PAGE_PROTNONE)));
136 }
137
pte_dirty(pte_t pte)138 static inline int pte_dirty(pte_t pte)
139 {
140 return pte_get_bits(pte, _PAGE_DIRTY);
141 }
142
pte_young(pte_t pte)143 static inline int pte_young(pte_t pte)
144 {
145 return pte_get_bits(pte, _PAGE_ACCESSED);
146 }
147
pte_needsync(pte_t pte)148 static inline int pte_needsync(pte_t pte)
149 {
150 return pte_get_bits(pte, _PAGE_NEEDSYNC);
151 }
152
153 /*
154 * =================================
155 * Flags setting section.
156 * =================================
157 */
158
pte_mkclean(pte_t pte)159 static inline pte_t pte_mkclean(pte_t pte)
160 {
161 pte_clear_bits(pte, _PAGE_DIRTY);
162 return(pte);
163 }
164
pte_mkold(pte_t pte)165 static inline pte_t pte_mkold(pte_t pte)
166 {
167 pte_clear_bits(pte, _PAGE_ACCESSED);
168 return(pte);
169 }
170
pte_wrprotect(pte_t pte)171 static inline pte_t pte_wrprotect(pte_t pte)
172 {
173 pte_clear_bits(pte, _PAGE_RW);
174 return pte;
175 }
176
pte_mkread(pte_t pte)177 static inline pte_t pte_mkread(pte_t pte)
178 {
179 pte_set_bits(pte, _PAGE_USER);
180 return pte;
181 }
182
pte_mkdirty(pte_t pte)183 static inline pte_t pte_mkdirty(pte_t pte)
184 {
185 pte_set_bits(pte, _PAGE_DIRTY);
186 return(pte);
187 }
188
pte_mkyoung(pte_t pte)189 static inline pte_t pte_mkyoung(pte_t pte)
190 {
191 pte_set_bits(pte, _PAGE_ACCESSED);
192 return(pte);
193 }
194
pte_mkwrite_novma(pte_t pte)195 static inline pte_t pte_mkwrite_novma(pte_t pte)
196 {
197 pte_set_bits(pte, _PAGE_RW);
198 return pte;
199 }
200
pte_mkuptodate(pte_t pte)201 static inline pte_t pte_mkuptodate(pte_t pte)
202 {
203 pte_clear_bits(pte, _PAGE_NEEDSYNC);
204 return pte;
205 }
206
pte_mkneedsync(pte_t pte)207 static inline pte_t pte_mkneedsync(pte_t pte)
208 {
209 pte_set_bits(pte, _PAGE_NEEDSYNC);
210 return(pte);
211 }
212
set_pte(pte_t * pteptr,pte_t pteval)213 static inline void set_pte(pte_t *pteptr, pte_t pteval)
214 {
215 pte_copy(*pteptr, pteval);
216
217 /* If it's a swap entry, it needs to be marked _PAGE_NEEDSYNC so
218 * update_pte_range knows to unmap it.
219 */
220
221 *pteptr = pte_mkneedsync(*pteptr);
222 }
223
224 #define PFN_PTE_SHIFT PAGE_SHIFT
225
um_tlb_mark_sync(struct mm_struct * mm,unsigned long start,unsigned long end)226 static inline void um_tlb_mark_sync(struct mm_struct *mm, unsigned long start,
227 unsigned long end)
228 {
229 if (!mm->context.sync_tlb_range_to) {
230 mm->context.sync_tlb_range_from = start;
231 mm->context.sync_tlb_range_to = end;
232 } else {
233 if (start < mm->context.sync_tlb_range_from)
234 mm->context.sync_tlb_range_from = start;
235 if (end > mm->context.sync_tlb_range_to)
236 mm->context.sync_tlb_range_to = end;
237 }
238 }
239
240 #define set_ptes set_ptes
set_ptes(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte,int nr)241 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
242 pte_t *ptep, pte_t pte, int nr)
243 {
244 /* Basically the default implementation */
245 size_t length = nr * PAGE_SIZE;
246
247 for (;;) {
248 set_pte(ptep, pte);
249 if (--nr == 0)
250 break;
251 ptep++;
252 pte = __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT));
253 }
254
255 um_tlb_mark_sync(mm, addr, addr + length);
256 }
257
258 #define __HAVE_ARCH_PTE_SAME
pte_same(pte_t pte_a,pte_t pte_b)259 static inline int pte_same(pte_t pte_a, pte_t pte_b)
260 {
261 return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEEDSYNC);
262 }
263
264 /*
265 * Conversion functions: convert a page and protection to a page entry,
266 * and a page entry and page directory to the page they refer to.
267 */
268
269 #define __virt_to_page(virt) phys_to_page(__pa(virt))
270 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
271
272 #define mk_pte(page, pgprot) \
273 ({ pte_t pte; \
274 \
275 pte_set_val(pte, page_to_phys(page), (pgprot)); \
276 pte;})
277
pte_modify(pte_t pte,pgprot_t newprot)278 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
279 {
280 pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
281 return pte;
282 }
283
284 /*
285 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
286 *
287 * this macro returns the index of the entry in the pmd page which would
288 * control the given virtual address
289 */
290 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
291
292 struct mm_struct;
293 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
294
295 #define update_mmu_cache(vma,address,ptep) do {} while (0)
296 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
297
298 /*
299 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
300 * are !pte_none() && !pte_present().
301 *
302 * Format of swap PTEs:
303 *
304 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
305 * 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
306 * <--------------- offset ----------------> E < type -> 0 0 0 1 0
307 *
308 * E is the exclusive marker that is not stored in swap entries.
309 * _PAGE_NEEDSYNC (bit 1) is always set to 1 in set_pte().
310 */
311 #define __swp_type(x) (((x).val >> 5) & 0x1f)
312 #define __swp_offset(x) ((x).val >> 11)
313
314 #define __swp_entry(type, offset) \
315 ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
316 #define __pte_to_swp_entry(pte) \
317 ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
318 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
319
pte_swp_exclusive(pte_t pte)320 static inline int pte_swp_exclusive(pte_t pte)
321 {
322 return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
323 }
324
pte_swp_mkexclusive(pte_t pte)325 static inline pte_t pte_swp_mkexclusive(pte_t pte)
326 {
327 pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
328 return pte;
329 }
330
pte_swp_clear_exclusive(pte_t pte)331 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
332 {
333 pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
334 return pte;
335 }
336
337 #endif
338