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 #define _PAGE_PRESENT 0x001 12 #define _PAGE_NEEDSYNC 0x002 13 #define _PAGE_RW 0x020 14 #define _PAGE_USER 0x040 15 #define _PAGE_ACCESSED 0x080 16 #define _PAGE_DIRTY 0x100 17 /* If _PAGE_PRESENT is clear, we use these: */ 18 #define _PAGE_PROTNONE 0x010 /* if the user mapped it with PROT_NONE; 19 pte_present gives true */ 20 21 /* We borrow bit 10 to store the exclusive marker in swap PTEs. */ 22 #define _PAGE_SWP_EXCLUSIVE 0x400 23 24 #if CONFIG_PGTABLE_LEVELS == 4 25 #include <asm/pgtable-4level.h> 26 #elif CONFIG_PGTABLE_LEVELS == 2 27 #include <asm/pgtable-2level.h> 28 #else 29 #error "Unsupported number of page table levels" 30 #endif 31 32 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 33 34 /* zero page used for uninitialized stuff */ 35 extern unsigned long *empty_zero_page; 36 37 /* Just any arbitrary offset to the start of the vmalloc VM area: the 38 * current 8MB value just means that there will be a 8MB "hole" after the 39 * physical memory until the kernel virtual memory starts. That means that 40 * any out-of-bounds memory accesses will hopefully be caught. 41 * The vmalloc() routines leaves a hole of 4kB between each vmalloced 42 * area for the same reason. ;) 43 */ 44 45 extern unsigned long end_iomem; 46 47 #define VMALLOC_OFFSET (__va_space) 48 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) 49 #define VMALLOC_END (TASK_SIZE-2*PAGE_SIZE) 50 #define MODULES_VADDR VMALLOC_START 51 #define MODULES_END VMALLOC_END 52 53 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY) 54 #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) 55 #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) 56 #define __PAGE_KERNEL_EXEC \ 57 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED) 58 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) 59 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED) 60 #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED) 61 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED) 62 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED) 63 #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) 64 65 /* 66 * The i386 can't do page protection for execute, and considers that the same 67 * are read. 68 * Also, write permissions imply read permissions. This is the closest we can 69 * get.. 70 */ 71 72 /* 73 * ZERO_PAGE is a global shared page that is always zero: used 74 * for zero-mapped memory areas etc.. 75 */ 76 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page) 77 78 #define pte_clear(mm, addr, xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEEDSYNC)) 79 80 #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC)) 81 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE) 82 83 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) 84 #define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEEDSYNC; } while (0) 85 86 #define pmd_needsync(x) (pmd_val(x) & _PAGE_NEEDSYNC) 87 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEEDSYNC) 88 89 #define pud_needsync(x) (pud_val(x) & _PAGE_NEEDSYNC) 90 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEEDSYNC) 91 92 #define p4d_needsync(x) (p4d_val(x) & _PAGE_NEEDSYNC) 93 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEEDSYNC) 94 95 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT) 96 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK) 97 98 #define pte_page(x) pfn_to_page(pte_pfn(x)) 99 100 #define pte_present(x) pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE)) 101 102 /* 103 * ================================= 104 * Flags checking section. 105 * ================================= 106 */ 107 108 static inline int pte_none(pte_t pte) 109 { 110 return pte_is_zero(pte); 111 } 112 113 /* 114 * The following only work if pte_present() is true. 115 * Undefined behaviour if not.. 116 */ 117 static inline int pte_read(pte_t pte) 118 { 119 return((pte_get_bits(pte, _PAGE_USER)) && 120 !(pte_get_bits(pte, _PAGE_PROTNONE))); 121 } 122 123 static inline int pte_exec(pte_t pte){ 124 return((pte_get_bits(pte, _PAGE_USER)) && 125 !(pte_get_bits(pte, _PAGE_PROTNONE))); 126 } 127 128 static inline int pte_write(pte_t pte) 129 { 130 return((pte_get_bits(pte, _PAGE_RW)) && 131 !(pte_get_bits(pte, _PAGE_PROTNONE))); 132 } 133 134 static inline int pte_dirty(pte_t pte) 135 { 136 return pte_get_bits(pte, _PAGE_DIRTY); 137 } 138 139 static inline int pte_young(pte_t pte) 140 { 141 return pte_get_bits(pte, _PAGE_ACCESSED); 142 } 143 144 static inline int pte_needsync(pte_t pte) 145 { 146 return pte_get_bits(pte, _PAGE_NEEDSYNC); 147 } 148 149 /* 150 * ================================= 151 * Flags setting section. 152 * ================================= 153 */ 154 155 static inline pte_t pte_mkclean(pte_t pte) 156 { 157 pte_clear_bits(pte, _PAGE_DIRTY); 158 return(pte); 159 } 160 161 static inline pte_t pte_mkold(pte_t pte) 162 { 163 pte_clear_bits(pte, _PAGE_ACCESSED); 164 return(pte); 165 } 166 167 static inline pte_t pte_wrprotect(pte_t pte) 168 { 169 pte_clear_bits(pte, _PAGE_RW); 170 return pte; 171 } 172 173 static inline pte_t pte_mkread(pte_t pte) 174 { 175 pte_set_bits(pte, _PAGE_USER); 176 return pte; 177 } 178 179 static inline pte_t pte_mkdirty(pte_t pte) 180 { 181 pte_set_bits(pte, _PAGE_DIRTY); 182 return(pte); 183 } 184 185 static inline pte_t pte_mkyoung(pte_t pte) 186 { 187 pte_set_bits(pte, _PAGE_ACCESSED); 188 return(pte); 189 } 190 191 static inline pte_t pte_mkwrite_novma(pte_t pte) 192 { 193 pte_set_bits(pte, _PAGE_RW); 194 return pte; 195 } 196 197 static inline pte_t pte_mkuptodate(pte_t pte) 198 { 199 pte_clear_bits(pte, _PAGE_NEEDSYNC); 200 return pte; 201 } 202 203 static inline pte_t pte_mkneedsync(pte_t pte) 204 { 205 pte_set_bits(pte, _PAGE_NEEDSYNC); 206 return(pte); 207 } 208 209 static inline void set_pte(pte_t *pteptr, pte_t pteval) 210 { 211 pte_copy(*pteptr, pteval); 212 213 /* If it's a swap entry, it needs to be marked _PAGE_NEEDSYNC so 214 * update_pte_range knows to unmap it. 215 */ 216 217 *pteptr = pte_mkneedsync(*pteptr); 218 } 219 220 #define PFN_PTE_SHIFT PAGE_SHIFT 221 222 static inline void um_tlb_mark_sync(struct mm_struct *mm, unsigned long start, 223 unsigned long end) 224 { 225 if (!mm->context.sync_tlb_range_to) { 226 mm->context.sync_tlb_range_from = start; 227 mm->context.sync_tlb_range_to = end; 228 } else { 229 if (start < mm->context.sync_tlb_range_from) 230 mm->context.sync_tlb_range_from = start; 231 if (end > mm->context.sync_tlb_range_to) 232 mm->context.sync_tlb_range_to = end; 233 } 234 } 235 236 #define set_ptes set_ptes 237 static inline void set_ptes(struct mm_struct *mm, unsigned long addr, 238 pte_t *ptep, pte_t pte, int nr) 239 { 240 /* Basically the default implementation */ 241 size_t length = nr * PAGE_SIZE; 242 243 for (;;) { 244 set_pte(ptep, pte); 245 if (--nr == 0) 246 break; 247 ptep++; 248 pte = __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT)); 249 } 250 251 um_tlb_mark_sync(mm, addr, addr + length); 252 } 253 254 #define __HAVE_ARCH_PTE_SAME 255 static inline int pte_same(pte_t pte_a, pte_t pte_b) 256 { 257 return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEEDSYNC); 258 } 259 260 /* 261 * Conversion functions: convert a page and protection to a page entry, 262 * and a page entry and page directory to the page they refer to. 263 */ 264 265 #define __virt_to_page(virt) phys_to_page(__pa(virt)) 266 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr) 267 268 #define mk_pte(page, pgprot) \ 269 ({ pte_t pte; \ 270 \ 271 pte_set_val(pte, page_to_phys(page), (pgprot)); \ 272 pte;}) 273 274 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 275 { 276 pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot); 277 return pte; 278 } 279 280 /* 281 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD] 282 * 283 * this macro returns the index of the entry in the pmd page which would 284 * control the given virtual address 285 */ 286 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) 287 288 struct mm_struct; 289 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr); 290 291 #define update_mmu_cache(vma,address,ptep) do {} while (0) 292 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0) 293 294 /* 295 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that 296 * are !pte_none() && !pte_present(). 297 * 298 * Format of swap PTEs: 299 * 300 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 301 * 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 0 302 * <--------------- offset ----------------> E < type -> 0 0 0 1 0 303 * 304 * E is the exclusive marker that is not stored in swap entries. 305 * _PAGE_NEEDSYNC (bit 1) is always set to 1 in set_pte(). 306 */ 307 #define __swp_type(x) (((x).val >> 5) & 0x1f) 308 #define __swp_offset(x) ((x).val >> 11) 309 310 #define __swp_entry(type, offset) \ 311 ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) }) 312 #define __pte_to_swp_entry(pte) \ 313 ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) 314 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 315 316 static inline int pte_swp_exclusive(pte_t pte) 317 { 318 return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE); 319 } 320 321 static inline pte_t pte_swp_mkexclusive(pte_t pte) 322 { 323 pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE); 324 return pte; 325 } 326 327 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 328 { 329 pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE); 330 return pte; 331 } 332 333 #endif 334