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