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/page.h>
12 #include <linux/mm_types.h>
13
14 #define _PAGE_PRESENT 0x001
15 #define _PAGE_NEEDSYNC 0x002
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 #if CONFIG_PGTABLE_LEVELS == 4
28 #include <asm/pgtable-4level.h>
29 #elif CONFIG_PGTABLE_LEVELS == 2
30 #include <asm/pgtable-2level.h>
31 #else
32 #error "Unsupported number of page table levels"
33 #endif
34
35 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
36
37 /* zero page used for uninitialized stuff */
38 extern unsigned long *empty_zero_page;
39
40 /* Just any arbitrary offset to the start of the vmalloc VM area: the
41 * current 8MB value just means that there will be a 8MB "hole" after the
42 * physical memory until the kernel virtual memory starts. That means that
43 * any out-of-bounds memory accesses will hopefully be caught.
44 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
45 * area for the same reason. ;)
46 */
47
48 extern unsigned long end_iomem;
49
50 #define VMALLOC_OFFSET (__va_space)
51 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
52 #define VMALLOC_END (TASK_SIZE-2*PAGE_SIZE)
53 #define MODULES_VADDR VMALLOC_START
54 #define MODULES_END VMALLOC_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_NEEDSYNC))
82
83 #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC))
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_NEEDSYNC; } while (0)
88
89 #define pmd_needsync(x) (pmd_val(x) & _PAGE_NEEDSYNC)
90 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEEDSYNC)
91
92 #define pud_needsync(x) (pud_val(x) & _PAGE_NEEDSYNC)
93 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEEDSYNC)
94
95 #define p4d_needsync(x) (p4d_val(x) & _PAGE_NEEDSYNC)
96 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEEDSYNC)
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_needsync(pte_t pte)147 static inline int pte_needsync(pte_t pte)
148 {
149 return pte_get_bits(pte, _PAGE_NEEDSYNC);
150 }
151
152 /*
153 * =================================
154 * Flags setting section.
155 * =================================
156 */
157
pte_mkclean(pte_t pte)158 static inline pte_t pte_mkclean(pte_t pte)
159 {
160 pte_clear_bits(pte, _PAGE_DIRTY);
161 return(pte);
162 }
163
pte_mkold(pte_t pte)164 static inline pte_t pte_mkold(pte_t pte)
165 {
166 pte_clear_bits(pte, _PAGE_ACCESSED);
167 return(pte);
168 }
169
pte_wrprotect(pte_t pte)170 static inline pte_t pte_wrprotect(pte_t pte)
171 {
172 pte_clear_bits(pte, _PAGE_RW);
173 return pte;
174 }
175
pte_mkread(pte_t pte)176 static inline pte_t pte_mkread(pte_t pte)
177 {
178 pte_set_bits(pte, _PAGE_USER);
179 return pte;
180 }
181
pte_mkdirty(pte_t pte)182 static inline pte_t pte_mkdirty(pte_t pte)
183 {
184 pte_set_bits(pte, _PAGE_DIRTY);
185 return(pte);
186 }
187
pte_mkyoung(pte_t pte)188 static inline pte_t pte_mkyoung(pte_t pte)
189 {
190 pte_set_bits(pte, _PAGE_ACCESSED);
191 return(pte);
192 }
193
pte_mkwrite_novma(pte_t pte)194 static inline pte_t pte_mkwrite_novma(pte_t pte)
195 {
196 pte_set_bits(pte, _PAGE_RW);
197 return pte;
198 }
199
pte_mkuptodate(pte_t pte)200 static inline pte_t pte_mkuptodate(pte_t pte)
201 {
202 pte_clear_bits(pte, _PAGE_NEEDSYNC);
203 return pte;
204 }
205
pte_mkneedsync(pte_t pte)206 static inline pte_t pte_mkneedsync(pte_t pte)
207 {
208 pte_set_bits(pte, _PAGE_NEEDSYNC);
209 return(pte);
210 }
211
set_pte(pte_t * pteptr,pte_t pteval)212 static inline void set_pte(pte_t *pteptr, pte_t pteval)
213 {
214 pte_copy(*pteptr, pteval);
215
216 /* If it's a swap entry, it needs to be marked _PAGE_NEEDSYNC so
217 * update_pte_range knows to unmap it.
218 */
219
220 *pteptr = pte_mkneedsync(*pteptr);
221 }
222
223 #define PFN_PTE_SHIFT PAGE_SHIFT
224
um_tlb_mark_sync(struct mm_struct * mm,unsigned long start,unsigned long end)225 static inline void um_tlb_mark_sync(struct mm_struct *mm, unsigned long start,
226 unsigned long end)
227 {
228 if (!mm->context.sync_tlb_range_to) {
229 mm->context.sync_tlb_range_from = start;
230 mm->context.sync_tlb_range_to = end;
231 } else {
232 if (start < mm->context.sync_tlb_range_from)
233 mm->context.sync_tlb_range_from = start;
234 if (end > mm->context.sync_tlb_range_to)
235 mm->context.sync_tlb_range_to = end;
236 }
237 }
238
239 #define set_ptes set_ptes
set_ptes(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pte,int nr)240 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
241 pte_t *ptep, pte_t pte, int nr)
242 {
243 /* Basically the default implementation */
244 size_t length = nr * PAGE_SIZE;
245
246 for (;;) {
247 set_pte(ptep, pte);
248 if (--nr == 0)
249 break;
250 ptep++;
251 pte = __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT));
252 }
253
254 um_tlb_mark_sync(mm, addr, addr + length);
255 }
256
257 #define __HAVE_ARCH_PTE_SAME
pte_same(pte_t pte_a,pte_t pte_b)258 static inline int pte_same(pte_t pte_a, pte_t pte_b)
259 {
260 return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEEDSYNC);
261 }
262
263 /*
264 * Conversion functions: convert a page and protection to a page entry,
265 * and a page entry and page directory to the page they refer to.
266 */
267
268 #define __virt_to_page(virt) phys_to_page(__pa(virt))
269 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
270
271 #define mk_pte(page, pgprot) \
272 ({ pte_t pte; \
273 \
274 pte_set_val(pte, page_to_phys(page), (pgprot)); \
275 pte;})
276
pte_modify(pte_t pte,pgprot_t newprot)277 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
278 {
279 pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
280 return pte;
281 }
282
283 /*
284 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
285 *
286 * this macro returns the index of the entry in the pmd page which would
287 * control the given virtual address
288 */
289 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
290
291 struct mm_struct;
292 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
293
294 #define update_mmu_cache(vma,address,ptep) do {} while (0)
295 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
296
297 /*
298 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
299 * are !pte_none() && !pte_present().
300 *
301 * Format of swap PTEs:
302 *
303 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
304 * 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
305 * <--------------- offset ----------------> E < type -> 0 0 0 1 0
306 *
307 * E is the exclusive marker that is not stored in swap entries.
308 * _PAGE_NEEDSYNC (bit 1) is always set to 1 in set_pte().
309 */
310 #define __swp_type(x) (((x).val >> 5) & 0x1f)
311 #define __swp_offset(x) ((x).val >> 11)
312
313 #define __swp_entry(type, offset) \
314 ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
315 #define __pte_to_swp_entry(pte) \
316 ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
317 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
318
pte_swp_exclusive(pte_t pte)319 static inline int pte_swp_exclusive(pte_t pte)
320 {
321 return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
322 }
323
pte_swp_mkexclusive(pte_t pte)324 static inline pte_t pte_swp_mkexclusive(pte_t pte)
325 {
326 pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
327 return pte;
328 }
329
pte_swp_clear_exclusive(pte_t pte)330 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
331 {
332 pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
333 return pte;
334 }
335
336 #endif
337