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 #include <asm-generic/pgtable-nopud.h> 14 15 #ifndef CONFIG_MMU 16 #include <asm/pgtable-nommu.h> 17 18 #else 19 20 #include <asm/page.h> 21 #include <asm/pgtable-hwdef.h> 22 23 24 #include <asm/tlbflush.h> 25 26 #ifdef CONFIG_ARM_LPAE 27 #include <asm/pgtable-3level.h> 28 #else 29 #include <asm/pgtable-2level.h> 30 #endif 31 32 /* 33 * Just any arbitrary offset to the start of the vmalloc VM area: the 34 * current 8MB value just means that there will be a 8MB "hole" after the 35 * physical memory until the kernel virtual memory starts. That means that 36 * any out-of-bounds memory accesses will hopefully be caught. 37 * The vmalloc() routines leaves a hole of 4kB between each vmalloced 38 * area for the same reason. ;) 39 */ 40 #define VMALLOC_OFFSET (8*1024*1024) 41 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) 42 #define VMALLOC_END 0xff800000UL 43 44 #define LIBRARY_TEXT_START 0x0c000000 45 46 #ifndef __ASSEMBLY__ 47 48 /* 49 * This is the lowest virtual address we can permit any user space 50 * mapping to be mapped at. This is particularly important for 51 * non-high vector CPUs. 52 */ 53 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2) 54 55 /* 56 * Use TASK_SIZE as the ceiling argument for free_pgtables() and 57 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd 58 * page shared between user and kernel). 59 */ 60 #ifdef CONFIG_ARM_LPAE 61 #define USER_PGTABLES_CEILING TASK_SIZE 62 #endif 63 64 /* 65 * The pgprot_* and protection_map entries will be fixed up in runtime 66 * to include the cachable and bufferable bits based on memory policy, 67 * as well as any architecture dependent bits like global/ASID and SMP 68 * shared mapping bits. 69 */ 70 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG 71 72 extern pgprot_t pgprot_user; 73 extern pgprot_t pgprot_kernel; 74 75 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) 76 77 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE) 78 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN) 79 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER) 80 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 81 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 82 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 83 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 84 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) 85 #define PAGE_KERNEL_EXEC pgprot_kernel 86 87 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE) 88 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) 89 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER) 90 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 91 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 92 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 93 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 94 95 #define __pgprot_modify(prot,mask,bits) \ 96 __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) 97 98 #define pgprot_noncached(prot) \ 99 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 100 101 #define pgprot_writecombine(prot) \ 102 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) 103 104 #define pgprot_stronglyordered(prot) \ 105 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 106 107 #define pgprot_device(prot) \ 108 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN) 109 110 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE 111 #define pgprot_dmacoherent(prot) \ 112 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) 113 #define __HAVE_PHYS_MEM_ACCESS_PROT 114 struct file; 115 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 116 unsigned long size, pgprot_t vma_prot); 117 #else 118 #define pgprot_dmacoherent(prot) \ 119 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN) 120 #endif 121 122 #endif /* __ASSEMBLY__ */ 123 124 /* 125 * The table below defines the page protection levels that we insert into our 126 * Linux page table version. These get translated into the best that the 127 * architecture can perform. Note that on most ARM hardware: 128 * 1) We cannot do execute protection 129 * 2) If we could do execute protection, then read is implied 130 * 3) write implies read permissions 131 */ 132 133 #ifndef __ASSEMBLY__ 134 135 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 136 137 #define pgdp_get(pgpd) READ_ONCE(*pgdp) 138 139 #define pud_page(pud) pmd_page(__pmd(pud_val(pud))) 140 #define pud_write(pud) pmd_write(__pmd(pud_val(pud))) 141 142 #define pmd_none(pmd) (!pmd_val(pmd)) 143 144 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 145 { 146 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 147 } 148 149 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) 150 151 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT) 152 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) 153 154 #define pte_page(pte) pfn_to_page(pte_pfn(pte)) 155 156 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0) 157 158 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \ 159 : !!(pte_val(pte) & (val))) 160 #define pte_isclear(pte, val) (!(pte_val(pte) & (val))) 161 162 #define pte_none(pte) (!pte_val(pte)) 163 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT)) 164 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID)) 165 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte)) 166 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY)) 167 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY)) 168 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG)) 169 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN)) 170 171 #define pte_valid_user(pte) \ 172 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte)) 173 174 static inline bool pte_access_permitted(pte_t pte, bool write) 175 { 176 pteval_t mask = L_PTE_PRESENT | L_PTE_USER; 177 pteval_t needed = mask; 178 179 if (write) 180 mask |= L_PTE_RDONLY; 181 182 return (pte_val(pte) & mask) == needed; 183 } 184 #define pte_access_permitted pte_access_permitted 185 186 #if __LINUX_ARM_ARCH__ < 6 187 static inline void __sync_icache_dcache(pte_t pteval) 188 { 189 } 190 #else 191 extern void __sync_icache_dcache(pte_t pteval); 192 #endif 193 194 #define PFN_PTE_SHIFT PAGE_SHIFT 195 196 void set_ptes(struct mm_struct *mm, unsigned long addr, 197 pte_t *ptep, pte_t pteval, unsigned int nr); 198 #define set_ptes set_ptes 199 200 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot) 201 { 202 pte_val(pte) &= ~pgprot_val(prot); 203 return pte; 204 } 205 206 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot) 207 { 208 pte_val(pte) |= pgprot_val(prot); 209 return pte; 210 } 211 212 static inline pte_t pte_wrprotect(pte_t pte) 213 { 214 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 215 } 216 217 static inline pte_t pte_mkwrite_novma(pte_t pte) 218 { 219 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 220 } 221 222 static inline pte_t pte_mkclean(pte_t pte) 223 { 224 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 225 } 226 227 static inline pte_t pte_mkdirty(pte_t pte) 228 { 229 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 230 } 231 232 static inline pte_t pte_mkold(pte_t pte) 233 { 234 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 235 } 236 237 static inline pte_t pte_mkyoung(pte_t pte) 238 { 239 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 240 } 241 242 static inline pte_t pte_mkexec(pte_t pte) 243 { 244 return clear_pte_bit(pte, __pgprot(L_PTE_XN)); 245 } 246 247 static inline pte_t pte_mknexec(pte_t pte) 248 { 249 return set_pte_bit(pte, __pgprot(L_PTE_XN)); 250 } 251 252 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 253 { 254 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER | 255 L_PTE_NONE | L_PTE_VALID; 256 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 257 return pte; 258 } 259 260 /* 261 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that 262 * are !pte_none() && !pte_present(). 263 * 264 * Format of swap PTEs: 265 * 266 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 267 * 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 0 268 * <------------------- offset ------------------> E < type -> 0 0 269 * 270 * E is the exclusive marker that is not stored in swap entries. 271 * 272 * This gives us up to 31 swap files and 64GB per swap file. Note that 273 * the offset field is always non-zero. 274 */ 275 #define __SWP_TYPE_SHIFT 2 276 #define __SWP_TYPE_BITS 5 277 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 278 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT + 1) 279 280 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 281 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 282 #define __swp_entry(type, offset) ((swp_entry_t) { (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \ 283 ((offset) << __SWP_OFFSET_SHIFT) }) 284 285 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 286 #define __swp_entry_to_pte(swp) __pte((swp).val) 287 288 static inline bool pte_swp_exclusive(pte_t pte) 289 { 290 return pte_isset(pte, L_PTE_SWP_EXCLUSIVE); 291 } 292 293 static inline pte_t pte_swp_mkexclusive(pte_t pte) 294 { 295 return set_pte_bit(pte, __pgprot(L_PTE_SWP_EXCLUSIVE)); 296 } 297 298 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 299 { 300 return clear_pte_bit(pte, __pgprot(L_PTE_SWP_EXCLUSIVE)); 301 } 302 303 /* 304 * It is an error for the kernel to have more swap files than we can 305 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES 306 * is increased beyond what we presently support. 307 */ 308 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 309 310 /* 311 * We provide our own arch_get_unmapped_area to cope with VIPT caches. 312 */ 313 #define HAVE_ARCH_UNMAPPED_AREA 314 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN 315 316 #endif /* !__ASSEMBLY__ */ 317 318 #endif /* CONFIG_MMU */ 319 320 #endif /* _ASMARM_PGTABLE_H */ 321