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);
sync_initial_page_table(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
mm_p4d_folded(struct mm_struct * mm)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 
native_set_pte(pte_t * ptep,pte_t pte)65 static inline void native_set_pte(pte_t *ptep, pte_t pte)
66 {
67 	WRITE_ONCE(*ptep, pte);
68 }
69 
native_pte_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)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 
native_set_pte_atomic(pte_t * ptep,pte_t pte)76 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
77 {
78 	native_set_pte(ptep, pte);
79 }
80 
native_set_pmd(pmd_t * pmdp,pmd_t pmd)81 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
82 {
83 	WRITE_ONCE(*pmdp, pmd);
84 }
85 
native_pmd_clear(pmd_t * pmd)86 static inline void native_pmd_clear(pmd_t *pmd)
87 {
88 	native_set_pmd(pmd, native_make_pmd(0));
89 }
90 
native_ptep_get_and_clear(pte_t * xp)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 
native_pmdp_get_and_clear(pmd_t * xp)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 
native_set_pud(pud_t * pudp,pud_t pud)117 static inline void native_set_pud(pud_t *pudp, pud_t pud)
118 {
119 	WRITE_ONCE(*pudp, pud);
120 }
121 
native_pud_clear(pud_t * pud)122 static inline void native_pud_clear(pud_t *pud)
123 {
124 	native_set_pud(pud, native_make_pud(0));
125 }
126 
native_pudp_get_and_clear(pud_t * xp)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 
native_set_p4d(p4d_t * p4dp,p4d_t p4d)142 static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
143 {
144 	pgd_t pgd;
145 
146 	if (pgtable_l5_enabled() || !IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) {
147 		WRITE_ONCE(*p4dp, p4d);
148 		return;
149 	}
150 
151 	pgd = native_make_pgd(native_p4d_val(p4d));
152 	pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd);
153 	WRITE_ONCE(*p4dp, native_make_p4d(native_pgd_val(pgd)));
154 }
155 
native_p4d_clear(p4d_t * p4d)156 static inline void native_p4d_clear(p4d_t *p4d)
157 {
158 	native_set_p4d(p4d, native_make_p4d(0));
159 }
160 
native_set_pgd(pgd_t * pgdp,pgd_t pgd)161 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
162 {
163 	WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
164 }
165 
native_pgd_clear(pgd_t * pgd)166 static inline void native_pgd_clear(pgd_t *pgd)
167 {
168 	native_set_pgd(pgd, native_make_pgd(0));
169 }
170 
171 /*
172  * Conversion functions: convert a page and protection to a page entry,
173  * and a page entry and page directory to the page they refer to.
174  */
175 
176 /* PGD - Level 4 access */
177 
178 /* PUD - Level 3 access */
179 
180 /* PMD - Level 2 access */
181 
182 /* PTE - Level 1 access */
183 
184 /*
185  * Encode and de-code a swap entry
186  *
187  * |     ...            | 11| 10|  9|8|7|6|5| 4| 3|2| 1|0| <- bit number
188  * |     ...            |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
189  * | TYPE (59-63) | ~OFFSET (9-58)  |0|0|X|X| X| E|F|SD|0| <- swp entry
190  *
191  * G (8) is aliased and used as a PROT_NONE indicator for
192  * !present ptes.  We need to start storing swap entries above
193  * there.  We also need to avoid using A and D because of an
194  * erratum where they can be incorrectly set by hardware on
195  * non-present PTEs.
196  *
197  * SD Bits 1-4 are not used in non-present format and available for
198  * special use described below:
199  *
200  * SD (1) in swp entry is used to store soft dirty bit, which helps us
201  * remember soft dirty over page migration
202  *
203  * F (2) in swp entry is used to record when a pagetable is
204  * writeprotected by userfaultfd WP support.
205  *
206  * E (3) in swp entry is used to rememeber PG_anon_exclusive.
207  *
208  * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
209  * but also L and G.
210  *
211  * The offset is inverted by a binary not operation to make the high
212  * physical bits set.
213  */
214 #define SWP_TYPE_BITS		5
215 
216 #define SWP_OFFSET_FIRST_BIT	(_PAGE_BIT_PROTNONE + 1)
217 
218 /* We always extract/encode the offset by shifting it all the way up, and then down again */
219 #define SWP_OFFSET_SHIFT	(SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
220 
221 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
222 
223 /* Extract the high bits for type */
224 #define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
225 
226 /* Shift up (to get rid of type), then down to get value */
227 #define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
228 
229 /*
230  * Shift the offset up "too far" by TYPE bits, then down again
231  * The offset is inverted by a binary not operation to make the high
232  * physical bits set.
233  */
234 #define __swp_entry(type, offset) ((swp_entry_t) { \
235 	(~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
236 	| ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
237 
238 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val((pte)) })
239 #define __pmd_to_swp_entry(pmd)		((swp_entry_t) { pmd_val((pmd)) })
240 #define __swp_entry_to_pte(x)		((pte_t) { .pte = (x).val })
241 #define __swp_entry_to_pmd(x)		((pmd_t) { .pmd = (x).val })
242 
243 extern int kern_addr_valid(unsigned long addr);
244 extern void cleanup_highmap(void);
245 
246 #define HAVE_ARCH_UNMAPPED_AREA
247 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
248 
249 #define PAGE_AGP    PAGE_KERNEL_NOCACHE
250 #define HAVE_PAGE_AGP 1
251 
252 /* fs/proc/kcore.c */
253 #define	kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
254 #define	kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
255 
256 #define __HAVE_ARCH_PTE_SAME
257 
258 #define vmemmap ((struct page *)VMEMMAP_START)
259 
260 extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
261 extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
262 
263 #define gup_fast_permitted gup_fast_permitted
gup_fast_permitted(unsigned long start,unsigned long end)264 static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
265 {
266 	if (end >> __VIRTUAL_MASK_SHIFT)
267 		return false;
268 	return true;
269 }
270 
271 #include <asm/pgtable-invert.h>
272 
273 #endif /* !__ASSEMBLY__ */
274 #endif /* _ASM_X86_PGTABLE_64_H */
275