1 /* 2 * arch/arm/include/asm/pgtable.h 3 * 4 * Copyright (C) 1995-2002 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #ifndef _ASMARM_PGTABLE_H 11 #define _ASMARM_PGTABLE_H 12 13 #include <linux/const.h> 14 #include <asm/proc-fns.h> 15 16 #ifndef CONFIG_MMU 17 18 #include <asm-generic/4level-fixup.h> 19 #include <asm/pgtable-nommu.h> 20 21 #else 22 23 #include <asm-generic/pgtable-nopud.h> 24 #include <asm/memory.h> 25 #include <asm/pgtable-hwdef.h> 26 27 28 #include <asm/tlbflush.h> 29 30 #ifdef CONFIG_ARM_LPAE 31 #include <asm/pgtable-3level.h> 32 #else 33 #include <asm/pgtable-2level.h> 34 #endif 35 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 #define VMALLOC_OFFSET (8*1024*1024) 45 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) 46 #define VMALLOC_END 0xff000000UL 47 48 #define LIBRARY_TEXT_START 0x0c000000 49 50 #ifndef __ASSEMBLY__ 51 extern void __pte_error(const char *file, int line, pte_t); 52 extern void __pmd_error(const char *file, int line, pmd_t); 53 extern void __pgd_error(const char *file, int line, pgd_t); 54 55 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte) 56 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd) 57 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd) 58 59 /* 60 * This is the lowest virtual address we can permit any user space 61 * mapping to be mapped at. This is particularly important for 62 * non-high vector CPUs. 63 */ 64 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2) 65 66 /* 67 * Use TASK_SIZE as the ceiling argument for free_pgtables() and 68 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd 69 * page shared between user and kernel). 70 */ 71 #ifdef CONFIG_ARM_LPAE 72 #define USER_PGTABLES_CEILING TASK_SIZE 73 #endif 74 75 /* 76 * The pgprot_* and protection_map entries will be fixed up in runtime 77 * to include the cachable and bufferable bits based on memory policy, 78 * as well as any architecture dependent bits like global/ASID and SMP 79 * shared mapping bits. 80 */ 81 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG 82 83 extern pgprot_t pgprot_user; 84 extern pgprot_t pgprot_kernel; 85 extern pgprot_t pgprot_hyp_device; 86 extern pgprot_t pgprot_s2; 87 extern pgprot_t pgprot_s2_device; 88 89 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) 90 91 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE) 92 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN) 93 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER) 94 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 95 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 96 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 97 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 98 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) 99 #define PAGE_KERNEL_EXEC pgprot_kernel 100 #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP) 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) 103 #define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY) 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 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE 126 #define pgprot_dmacoherent(prot) \ 127 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) 128 #define __HAVE_PHYS_MEM_ACCESS_PROT 129 struct file; 130 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 131 unsigned long size, pgprot_t vma_prot); 132 #else 133 #define pgprot_dmacoherent(prot) \ 134 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN) 135 #endif 136 137 #endif /* __ASSEMBLY__ */ 138 139 /* 140 * The table below defines the page protection levels that we insert into our 141 * Linux page table version. These get translated into the best that the 142 * architecture can perform. Note that on most ARM hardware: 143 * 1) We cannot do execute protection 144 * 2) If we could do execute protection, then read is implied 145 * 3) write implies read permissions 146 */ 147 #define __P000 __PAGE_NONE 148 #define __P001 __PAGE_READONLY 149 #define __P010 __PAGE_COPY 150 #define __P011 __PAGE_COPY 151 #define __P100 __PAGE_READONLY_EXEC 152 #define __P101 __PAGE_READONLY_EXEC 153 #define __P110 __PAGE_COPY_EXEC 154 #define __P111 __PAGE_COPY_EXEC 155 156 #define __S000 __PAGE_NONE 157 #define __S001 __PAGE_READONLY 158 #define __S010 __PAGE_SHARED 159 #define __S011 __PAGE_SHARED 160 #define __S100 __PAGE_READONLY_EXEC 161 #define __S101 __PAGE_READONLY_EXEC 162 #define __S110 __PAGE_SHARED_EXEC 163 #define __S111 __PAGE_SHARED_EXEC 164 165 #ifndef __ASSEMBLY__ 166 /* 167 * ZERO_PAGE is a global shared page that is always zero: used 168 * for zero-mapped memory areas etc.. 169 */ 170 extern struct page *empty_zero_page; 171 #define ZERO_PAGE(vaddr) (empty_zero_page) 172 173 174 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 175 176 /* to find an entry in a page-table-directory */ 177 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) 178 179 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 180 181 /* to find an entry in a kernel page-table-directory */ 182 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) 183 184 #define pmd_none(pmd) (!pmd_val(pmd)) 185 #define pmd_present(pmd) (pmd_val(pmd)) 186 187 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 188 { 189 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 190 } 191 192 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) 193 194 #ifndef CONFIG_HIGHPTE 195 #define __pte_map(pmd) pmd_page_vaddr(*(pmd)) 196 #define __pte_unmap(pte) do { } while (0) 197 #else 198 #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd))) 199 #define __pte_unmap(pte) kunmap_atomic(pte) 200 #endif 201 202 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 203 204 #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 205 206 #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr)) 207 #define pte_unmap(pte) __pte_unmap(pte) 208 209 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT) 210 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) 211 212 #define pte_page(pte) pfn_to_page(pte_pfn(pte)) 213 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot) 214 215 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0) 216 217 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \ 218 : !!(pte_val(pte) & (val))) 219 #define pte_isclear(pte, val) (!(pte_val(pte) & (val))) 220 221 #define pte_none(pte) (!pte_val(pte)) 222 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT)) 223 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID)) 224 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte)) 225 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY)) 226 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY)) 227 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG)) 228 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN)) 229 230 #define pte_valid_user(pte) \ 231 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte)) 232 233 #if __LINUX_ARM_ARCH__ < 6 234 static inline void __sync_icache_dcache(pte_t pteval) 235 { 236 } 237 #else 238 extern void __sync_icache_dcache(pte_t pteval); 239 #endif 240 241 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, 242 pte_t *ptep, pte_t pteval) 243 { 244 unsigned long ext = 0; 245 246 if (addr < TASK_SIZE && pte_valid_user(pteval)) { 247 if (!pte_special(pteval)) 248 __sync_icache_dcache(pteval); 249 ext |= PTE_EXT_NG; 250 } 251 252 set_pte_ext(ptep, pteval, ext); 253 } 254 255 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot) 256 { 257 pte_val(pte) &= ~pgprot_val(prot); 258 return pte; 259 } 260 261 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot) 262 { 263 pte_val(pte) |= pgprot_val(prot); 264 return pte; 265 } 266 267 static inline pte_t pte_wrprotect(pte_t pte) 268 { 269 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 270 } 271 272 static inline pte_t pte_mkwrite(pte_t pte) 273 { 274 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY)); 275 } 276 277 static inline pte_t pte_mkclean(pte_t pte) 278 { 279 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 280 } 281 282 static inline pte_t pte_mkdirty(pte_t pte) 283 { 284 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY)); 285 } 286 287 static inline pte_t pte_mkold(pte_t pte) 288 { 289 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 290 } 291 292 static inline pte_t pte_mkyoung(pte_t pte) 293 { 294 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG)); 295 } 296 297 static inline pte_t pte_mkexec(pte_t pte) 298 { 299 return clear_pte_bit(pte, __pgprot(L_PTE_XN)); 300 } 301 302 static inline pte_t pte_mknexec(pte_t pte) 303 { 304 return set_pte_bit(pte, __pgprot(L_PTE_XN)); 305 } 306 307 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 308 { 309 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER | 310 L_PTE_NONE | L_PTE_VALID; 311 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 312 return pte; 313 } 314 315 /* 316 * Encode and decode a swap entry. Swap entries are stored in the Linux 317 * page tables as follows: 318 * 319 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 320 * 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 0 321 * <--------------- offset ------------------------> < type -> 0 0 322 * 323 * This gives us up to 31 swap files and 128GB per swap file. Note that 324 * the offset field is always non-zero. 325 */ 326 #define __SWP_TYPE_SHIFT 2 327 #define __SWP_TYPE_BITS 5 328 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 329 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 330 331 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 332 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 333 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) 334 335 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 336 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 337 338 /* 339 * It is an error for the kernel to have more swap files than we can 340 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES 341 * is increased beyond what we presently support. 342 */ 343 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 344 345 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ 346 /* FIXME: this is not correct */ 347 #define kern_addr_valid(addr) (1) 348 349 #include <asm-generic/pgtable.h> 350 351 /* 352 * We provide our own arch_get_unmapped_area to cope with VIPT caches. 353 */ 354 #define HAVE_ARCH_UNMAPPED_AREA 355 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN 356 357 #define pgtable_cache_init() do { } while (0) 358 359 #endif /* !__ASSEMBLY__ */ 360 361 #endif /* CONFIG_MMU */ 362 363 #endif /* _ASMARM_PGTABLE_H */ 364