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