1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * arch/arm/include/asm/pgtable.h 4 * 5 * Copyright (C) 1995-2002 Russell King 6 */ 7 #ifndef _ASMARM_PGTABLE_H 8 #define _ASMARM_PGTABLE_H 9 10 #include <linux/const.h> 11 #include <asm/proc-fns.h> 12 13 #ifndef CONFIG_MMU 14 15 #include <asm-generic/4level-fixup.h> 16 #include <asm/pgtable-nommu.h> 17 18 #else 19 20 #define __ARCH_USE_5LEVEL_HACK 21 #include <asm-generic/pgtable-nopud.h> 22 #include <asm/memory.h> 23 #include <asm/pgtable-hwdef.h> 24 25 26 #include <asm/tlbflush.h> 27 28 #ifdef CONFIG_ARM_LPAE 29 #include <asm/pgtable-3level.h> 30 #else 31 #include <asm/pgtable-2level.h> 32 #endif 33 34 /* 35 * Just any arbitrary offset to the start of the vmalloc VM area: the 36 * current 8MB value just means that there will be a 8MB "hole" after the 37 * physical memory until the kernel virtual memory starts. That means that 38 * any out-of-bounds memory accesses will hopefully be caught. 39 * The vmalloc() routines leaves a hole of 4kB between each vmalloced 40 * area for the same reason. ;) 41 */ 42 #define VMALLOC_OFFSET (8*1024*1024) 43 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) 44 #define VMALLOC_END 0xff800000UL 45 46 #define LIBRARY_TEXT_START 0x0c000000 47 48 #ifndef __ASSEMBLY__ 49 extern void __pte_error(const char *file, int line, pte_t); 50 extern void __pmd_error(const char *file, int line, pmd_t); 51 extern void __pgd_error(const char *file, int line, pgd_t); 52 53 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte) 54 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd) 55 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd) 56 57 /* 58 * This is the lowest virtual address we can permit any user space 59 * mapping to be mapped at. This is particularly important for 60 * non-high vector CPUs. 61 */ 62 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2) 63 64 /* 65 * Use TASK_SIZE as the ceiling argument for free_pgtables() and 66 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd 67 * page shared between user and kernel). 68 */ 69 #ifdef CONFIG_ARM_LPAE 70 #define USER_PGTABLES_CEILING TASK_SIZE 71 #endif 72 73 /* 74 * The pgprot_* and protection_map entries will be fixed up in runtime 75 * to include the cachable and bufferable bits based on memory policy, 76 * as well as any architecture dependent bits like global/ASID and SMP 77 * shared mapping bits. 78 */ 79 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG 80 81 extern pgprot_t pgprot_user; 82 extern pgprot_t pgprot_kernel; 83 extern pgprot_t pgprot_hyp_device; 84 extern pgprot_t pgprot_s2; 85 extern pgprot_t pgprot_s2_device; 86 87 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) 88 89 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE) 90 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN) 91 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER) 92 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 93 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 94 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 95 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 96 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) 97 #define PAGE_KERNEL_EXEC pgprot_kernel 98 #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_XN) 99 #define PAGE_HYP_EXEC _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY) 100 #define PAGE_HYP_RO _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY | L_PTE_XN) 101 #define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP) 102 #define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY | L_PTE_XN) 103 #define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY | L_PTE_XN) 104 105 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE) 106 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) 107 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER) 108 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 109 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 110 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 111 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 112 113 #define __pgprot_modify(prot,mask,bits) \ 114 __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) 115 116 #define pgprot_noncached(prot) \ 117 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 118 119 #define pgprot_writecombine(prot) \ 120 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) 121 122 #define pgprot_stronglyordered(prot) \ 123 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 124 125 #define pgprot_device(prot) \ 126 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN) 127 128 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE 129 #define pgprot_dmacoherent(prot) \ 130 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) 131 #define __HAVE_PHYS_MEM_ACCESS_PROT 132 struct file; 133 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 134 unsigned long size, pgprot_t vma_prot); 135 #else 136 #define pgprot_dmacoherent(prot) \ 137 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN) 138 #endif 139 140 #endif /* __ASSEMBLY__ */ 141 142 /* 143 * The table below defines the page protection levels that we insert into our 144 * Linux page table version. These get translated into the best that the 145 * architecture can perform. Note that on most ARM hardware: 146 * 1) We cannot do execute protection 147 * 2) If we could do execute protection, then read is implied 148 * 3) write implies read permissions 149 */ 150 #define __P000 __PAGE_NONE 151 #define __P001 __PAGE_READONLY 152 #define __P010 __PAGE_COPY 153 #define __P011 __PAGE_COPY 154 #define __P100 __PAGE_READONLY_EXEC 155 #define __P101 __PAGE_READONLY_EXEC 156 #define __P110 __PAGE_COPY_EXEC 157 #define __P111 __PAGE_COPY_EXEC 158 159 #define __S000 __PAGE_NONE 160 #define __S001 __PAGE_READONLY 161 #define __S010 __PAGE_SHARED 162 #define __S011 __PAGE_SHARED 163 #define __S100 __PAGE_READONLY_EXEC 164 #define __S101 __PAGE_READONLY_EXEC 165 #define __S110 __PAGE_SHARED_EXEC 166 #define __S111 __PAGE_SHARED_EXEC 167 168 #ifndef __ASSEMBLY__ 169 /* 170 * ZERO_PAGE is a global shared page that is always zero: used 171 * for zero-mapped memory areas etc.. 172 */ 173 extern struct page *empty_zero_page; 174 #define ZERO_PAGE(vaddr) (empty_zero_page) 175 176 177 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 178 179 /* to find an entry in a page-table-directory */ 180 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) 181 182 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 183 184 /* to find an entry in a kernel page-table-directory */ 185 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) 186 187 #define pmd_none(pmd) (!pmd_val(pmd)) 188 189 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 190 { 191 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 192 } 193 194 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) 195 196 #ifndef CONFIG_HIGHPTE 197 #define __pte_map(pmd) pmd_page_vaddr(*(pmd)) 198 #define __pte_unmap(pte) do { } while (0) 199 #else 200 #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd))) 201 #define __pte_unmap(pte) kunmap_atomic(pte) 202 #endif 203 204 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 205 206 #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 207 208 #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr)) 209 #define pte_unmap(pte) __pte_unmap(pte) 210 211 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT) 212 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) 213 214 #define pte_page(pte) pfn_to_page(pte_pfn(pte)) 215 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot) 216 217 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0) 218 219 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \ 220 : !!(pte_val(pte) & (val))) 221 #define pte_isclear(pte, val) (!(pte_val(pte) & (val))) 222 223 #define pte_none(pte) (!pte_val(pte)) 224 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT)) 225 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID)) 226 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte)) 227 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY)) 228 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY)) 229 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG)) 230 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN)) 231 232 #define pte_valid_user(pte) \ 233 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte)) 234 235 static inline bool pte_access_permitted(pte_t pte, bool write) 236 { 237 pteval_t mask = L_PTE_PRESENT | L_PTE_USER; 238 pteval_t needed = mask; 239 240 if (write) 241 mask |= L_PTE_RDONLY; 242 243 return (pte_val(pte) & mask) == needed; 244 } 245 #define pte_access_permitted pte_access_permitted 246 247 #if __LINUX_ARM_ARCH__ < 6 248 static inline void __sync_icache_dcache(pte_t pteval) 249 { 250 } 251 #else 252 extern void __sync_icache_dcache(pte_t pteval); 253 #endif 254 255 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, 256 pte_t *ptep, pte_t pteval) 257 { 258 unsigned long ext = 0; 259 260 if (addr < TASK_SIZE && pte_valid_user(pteval)) { 261 if (!pte_special(pteval)) 262 __sync_icache_dcache(pteval); 263 ext |= PTE_EXT_NG; 264 } 265 266 set_pte_ext(ptep, pteval, ext); 267 } 268 269 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot) 270 { 271 pte_val(pte) &= ~pgprot_val(prot); 272 return pte; 273 } 274 275 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot) 276 { 277 pte_val(pte) |= pgprot_val(prot); 278 return pte; 279 } 280 281 static inline pte_t pte_wrprotect(pte_t pte) 282 { 283 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 284 } 285 286 static inline pte_t pte_mkwrite(pte_t pte) 287 { 288 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 289 } 290 291 static inline pte_t pte_mkclean(pte_t pte) 292 { 293 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 294 } 295 296 static inline pte_t pte_mkdirty(pte_t pte) 297 { 298 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 299 } 300 301 static inline pte_t pte_mkold(pte_t pte) 302 { 303 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 304 } 305 306 static inline pte_t pte_mkyoung(pte_t pte) 307 { 308 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 309 } 310 311 static inline pte_t pte_mkexec(pte_t pte) 312 { 313 return clear_pte_bit(pte, __pgprot(L_PTE_XN)); 314 } 315 316 static inline pte_t pte_mknexec(pte_t pte) 317 { 318 return set_pte_bit(pte, __pgprot(L_PTE_XN)); 319 } 320 321 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 322 { 323 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER | 324 L_PTE_NONE | L_PTE_VALID; 325 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 326 return pte; 327 } 328 329 /* 330 * Encode and decode a swap entry. Swap entries are stored in the Linux 331 * page tables as follows: 332 * 333 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 334 * 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 0 335 * <--------------- offset ------------------------> < type -> 0 0 336 * 337 * This gives us up to 31 swap files and 128GB per swap file. Note that 338 * the offset field is always non-zero. 339 */ 340 #define __SWP_TYPE_SHIFT 2 341 #define __SWP_TYPE_BITS 5 342 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 343 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 344 345 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 346 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 347 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) 348 349 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 350 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 351 352 /* 353 * It is an error for the kernel to have more swap files than we can 354 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES 355 * is increased beyond what we presently support. 356 */ 357 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 358 359 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ 360 /* FIXME: this is not correct */ 361 #define kern_addr_valid(addr) (1) 362 363 #include <asm-generic/pgtable.h> 364 365 /* 366 * We provide our own arch_get_unmapped_area to cope with VIPT caches. 367 */ 368 #define HAVE_ARCH_UNMAPPED_AREA 369 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN 370 371 #endif /* !__ASSEMBLY__ */ 372 373 #endif /* CONFIG_MMU */ 374 375 #endif /* _ASMARM_PGTABLE_H */ 376