1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PGTABLE_64_H
3 #define _ASM_X86_PGTABLE_64_H
4
5 #include <linux/const.h>
6 #include <asm/pgtable_64_types.h>
7
8 #ifndef __ASSEMBLY__
9
10 /*
11 * This file contains the functions and defines necessary to modify and use
12 * the x86-64 page table tree.
13 */
14 #include <asm/processor.h>
15 #include <linux/bitops.h>
16 #include <linux/threads.h>
17 #include <asm/fixmap.h>
18
19 extern p4d_t level4_kernel_pgt[512];
20 extern p4d_t level4_ident_pgt[512];
21 extern pud_t level3_kernel_pgt[512];
22 extern pud_t level3_ident_pgt[512];
23 extern pmd_t level2_kernel_pgt[512];
24 extern pmd_t level2_fixmap_pgt[512];
25 extern pmd_t level2_ident_pgt[512];
26 extern pte_t level1_fixmap_pgt[512 * FIXMAP_PMD_NUM];
27 extern pgd_t init_top_pgt[];
28
29 #define swapper_pg_dir init_top_pgt
30
31 extern void paging_init(void);
32 static inline void sync_initial_page_table(void) { }
33
34 #define pte_ERROR(e) \
35 pr_err("%s:%d: bad pte %p(%016lx)\n", \
36 __FILE__, __LINE__, &(e), pte_val(e))
37 #define pmd_ERROR(e) \
38 pr_err("%s:%d: bad pmd %p(%016lx)\n", \
39 __FILE__, __LINE__, &(e), pmd_val(e))
40 #define pud_ERROR(e) \
41 pr_err("%s:%d: bad pud %p(%016lx)\n", \
42 __FILE__, __LINE__, &(e), pud_val(e))
43
44 #if CONFIG_PGTABLE_LEVELS >= 5
45 #define p4d_ERROR(e) \
46 pr_err("%s:%d: bad p4d %p(%016lx)\n", \
47 __FILE__, __LINE__, &(e), p4d_val(e))
48 #endif
49
50 #define pgd_ERROR(e) \
51 pr_err("%s:%d: bad pgd %p(%016lx)\n", \
52 __FILE__, __LINE__, &(e), pgd_val(e))
53
54 struct mm_struct;
55
56 #define mm_p4d_folded mm_p4d_folded
57 static inline bool mm_p4d_folded(struct mm_struct *mm)
58 {
59 return !pgtable_l5_enabled();
60 }
61
62 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
63 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
64
65 static inline void native_set_pte(pte_t *ptep, pte_t pte)
66 {
67 WRITE_ONCE(*ptep, pte);
68 }
69
70 static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr,
71 pte_t *ptep)
72 {
73 native_set_pte(ptep, native_make_pte(0));
74 }
75
76 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
77 {
78 native_set_pte(ptep, pte);
79 }
80
81 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
82 {
83 WRITE_ONCE(*pmdp, pmd);
84 }
85
86 static inline void native_pmd_clear(pmd_t *pmd)
87 {
88 native_set_pmd(pmd, native_make_pmd(0));
89 }
90
91 static inline pte_t native_ptep_get_and_clear(pte_t *xp)
92 {
93 #ifdef CONFIG_SMP
94 return native_make_pte(xchg(&xp->pte, 0));
95 #else
96 /* native_local_ptep_get_and_clear,
97 but duplicated because of cyclic dependency */
98 pte_t ret = *xp;
99 native_pte_clear(NULL, 0, xp);
100 return ret;
101 #endif
102 }
103
104 static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
105 {
106 #ifdef CONFIG_SMP
107 return native_make_pmd(xchg(&xp->pmd, 0));
108 #else
109 /* native_local_pmdp_get_and_clear,
110 but duplicated because of cyclic dependency */
111 pmd_t ret = *xp;
112 native_pmd_clear(xp);
113 return ret;
114 #endif
115 }
116
117 static inline void native_set_pud(pud_t *pudp, pud_t pud)
118 {
119 WRITE_ONCE(*pudp, pud);
120 }
121
122 static inline void native_pud_clear(pud_t *pud)
123 {
124 native_set_pud(pud, native_make_pud(0));
125 }
126
127 static inline pud_t native_pudp_get_and_clear(pud_t *xp)
128 {
129 #ifdef CONFIG_SMP
130 return native_make_pud(xchg(&xp->pud, 0));
131 #else
132 /* native_local_pudp_get_and_clear,
133 * but duplicated because of cyclic dependency
134 */
135 pud_t ret = *xp;
136
137 native_pud_clear(xp);
138 return ret;
139 #endif
140 }
141
142 static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
143 {
144 pgd_t pgd;
145
146 if (pgtable_l5_enabled() ||
147 !IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION)) {
148 WRITE_ONCE(*p4dp, p4d);
149 return;
150 }
151
152 pgd = native_make_pgd(native_p4d_val(p4d));
153 pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd);
154 WRITE_ONCE(*p4dp, native_make_p4d(native_pgd_val(pgd)));
155 }
156
157 static inline void native_p4d_clear(p4d_t *p4d)
158 {
159 native_set_p4d(p4d, native_make_p4d(0));
160 }
161
162 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
163 {
164 WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
165 }
166
167 static inline void native_pgd_clear(pgd_t *pgd)
168 {
169 native_set_pgd(pgd, native_make_pgd(0));
170 }
171
172 /*
173 * Conversion functions: convert a page and protection to a page entry,
174 * and a page entry and page directory to the page they refer to.
175 */
176
177 /* PGD - Level 4 access */
178
179 /* PUD - Level 3 access */
180
181 /* PMD - Level 2 access */
182
183 /* PTE - Level 1 access */
184
185 /*
186 * Encode and de-code a swap entry
187 *
188 * | ... | 11| 10| 9|8|7|6|5| 4| 3|2| 1|0| <- bit number
189 * | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
190 * | TYPE (59-63) | ~OFFSET (9-58) |0|0|X|X| X| E|F|SD|0| <- swp entry
191 *
192 * G (8) is aliased and used as a PROT_NONE indicator for
193 * !present ptes. We need to start storing swap entries above
194 * there. We also need to avoid using A and D because of an
195 * erratum where they can be incorrectly set by hardware on
196 * non-present PTEs.
197 *
198 * SD Bits 1-4 are not used in non-present format and available for
199 * special use described below:
200 *
201 * SD (1) in swp entry is used to store soft dirty bit, which helps us
202 * remember soft dirty over page migration
203 *
204 * F (2) in swp entry is used to record when a pagetable is
205 * writeprotected by userfaultfd WP support.
206 *
207 * E (3) in swp entry is used to remember PG_anon_exclusive.
208 *
209 * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
210 * but also L and G.
211 *
212 * The offset is inverted by a binary not operation to make the high
213 * physical bits set.
214 */
215 #define SWP_TYPE_BITS 5
216
217 #define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
218
219 /* We always extract/encode the offset by shifting it all the way up, and then down again */
220 #define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
221
222 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
223
224 /* Extract the high bits for type */
225 #define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
226
227 /* Shift up (to get rid of type), then down to get value */
228 #define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
229
230 /*
231 * Shift the offset up "too far" by TYPE bits, then down again
232 * The offset is inverted by a binary not operation to make the high
233 * physical bits set.
234 */
235 #define __swp_entry(type, offset) ((swp_entry_t) { \
236 (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
237 | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
238
239 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) })
240 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val((pmd)) })
241 #define __swp_entry_to_pte(x) (__pte((x).val))
242 #define __swp_entry_to_pmd(x) (__pmd((x).val))
243
244 extern void cleanup_highmap(void);
245
246 #define HAVE_ARCH_UNMAPPED_AREA
247 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
248 #define HAVE_ARCH_UNMAPPED_AREA_VMFLAGS
249
250 #define PAGE_AGP PAGE_KERNEL_NOCACHE
251 #define HAVE_PAGE_AGP 1
252
253 /* fs/proc/kcore.c */
254 #define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
255 #define kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
256
257 #define __HAVE_ARCH_PTE_SAME
258
259 #define vmemmap ((struct page *)VMEMMAP_START)
260
261 extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
262 extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
263
264 #define gup_fast_permitted gup_fast_permitted
265 static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
266 {
267 if (end >> __VIRTUAL_MASK_SHIFT)
268 return false;
269 return true;
270 }
271
272 #include <asm/pgtable-invert.h>
273
274 #endif /* !__ASSEMBLY__ */
275 #endif /* _ASM_X86_PGTABLE_64_H */
276
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