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 #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 0xff000000UL 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 62 63 /* 64 * The pgprot_* and protection_map entries will be fixed up in runtime 65 * to include the cachable and bufferable bits based on memory policy, 66 * as well as any architecture dependent bits like global/ASID and SMP 67 * shared mapping bits. 68 */ 69 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG 70 71 extern pgprot_t pgprot_user; 72 extern pgprot_t pgprot_kernel; 73 74 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b)) 75 76 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE) 77 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN) 78 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER) 79 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 80 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 81 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 82 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) 83 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) 84 #define PAGE_KERNEL_EXEC pgprot_kernel 85 86 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE) 87 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) 88 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER) 89 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 90 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 91 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) 92 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY) 93 94 #define __pgprot_modify(prot,mask,bits) \ 95 __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) 96 97 #define pgprot_noncached(prot) \ 98 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 99 100 #define pgprot_writecombine(prot) \ 101 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) 102 103 #define pgprot_stronglyordered(prot) \ 104 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) 105 106 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE 107 #define pgprot_dmacoherent(prot) \ 108 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN) 109 #define __HAVE_PHYS_MEM_ACCESS_PROT 110 struct file; 111 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 112 unsigned long size, pgprot_t vma_prot); 113 #else 114 #define pgprot_dmacoherent(prot) \ 115 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN) 116 #endif 117 118 #endif /* __ASSEMBLY__ */ 119 120 /* 121 * The table below defines the page protection levels that we insert into our 122 * Linux page table version. These get translated into the best that the 123 * architecture can perform. Note that on most ARM hardware: 124 * 1) We cannot do execute protection 125 * 2) If we could do execute protection, then read is implied 126 * 3) write implies read permissions 127 */ 128 #define __P000 __PAGE_NONE 129 #define __P001 __PAGE_READONLY 130 #define __P010 __PAGE_COPY 131 #define __P011 __PAGE_COPY 132 #define __P100 __PAGE_READONLY_EXEC 133 #define __P101 __PAGE_READONLY_EXEC 134 #define __P110 __PAGE_COPY_EXEC 135 #define __P111 __PAGE_COPY_EXEC 136 137 #define __S000 __PAGE_NONE 138 #define __S001 __PAGE_READONLY 139 #define __S010 __PAGE_SHARED 140 #define __S011 __PAGE_SHARED 141 #define __S100 __PAGE_READONLY_EXEC 142 #define __S101 __PAGE_READONLY_EXEC 143 #define __S110 __PAGE_SHARED_EXEC 144 #define __S111 __PAGE_SHARED_EXEC 145 146 #ifndef __ASSEMBLY__ 147 /* 148 * ZERO_PAGE is a global shared page that is always zero: used 149 * for zero-mapped memory areas etc.. 150 */ 151 extern struct page *empty_zero_page; 152 #define ZERO_PAGE(vaddr) (empty_zero_page) 153 154 155 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 156 157 /* to find an entry in a page-table-directory */ 158 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) 159 160 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) 161 162 /* to find an entry in a kernel page-table-directory */ 163 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) 164 165 #define pmd_none(pmd) (!pmd_val(pmd)) 166 #define pmd_present(pmd) (pmd_val(pmd)) 167 168 static inline pte_t *pmd_page_vaddr(pmd_t pmd) 169 { 170 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK); 171 } 172 173 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) 174 175 #ifndef CONFIG_HIGHPTE 176 #define __pte_map(pmd) pmd_page_vaddr(*(pmd)) 177 #define __pte_unmap(pte) do { } while (0) 178 #else 179 #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd))) 180 #define __pte_unmap(pte) kunmap_atomic(pte) 181 #endif 182 183 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 184 185 #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr)) 186 187 #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr)) 188 #define pte_unmap(pte) __pte_unmap(pte) 189 190 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT) 191 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) 192 193 #define pte_page(pte) pfn_to_page(pte_pfn(pte)) 194 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot) 195 196 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0) 197 198 #define pte_none(pte) (!pte_val(pte)) 199 #define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT) 200 #define pte_write(pte) (!(pte_val(pte) & L_PTE_RDONLY)) 201 #define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY) 202 #define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG) 203 #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN)) 204 #define pte_special(pte) (0) 205 206 #define pte_present_user(pte) (pte_present(pte) && (pte_val(pte) & L_PTE_USER)) 207 208 #if __LINUX_ARM_ARCH__ < 6 209 static inline void __sync_icache_dcache(pte_t pteval) 210 { 211 } 212 #else 213 extern void __sync_icache_dcache(pte_t pteval); 214 #endif 215 216 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, 217 pte_t *ptep, pte_t pteval) 218 { 219 unsigned long ext = 0; 220 221 if (addr < TASK_SIZE && pte_present_user(pteval)) { 222 __sync_icache_dcache(pteval); 223 ext |= PTE_EXT_NG; 224 } 225 226 set_pte_ext(ptep, pteval, ext); 227 } 228 229 #define PTE_BIT_FUNC(fn,op) \ 230 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } 231 232 PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY); 233 PTE_BIT_FUNC(mkwrite, &= ~L_PTE_RDONLY); 234 PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY); 235 PTE_BIT_FUNC(mkdirty, |= L_PTE_DIRTY); 236 PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG); 237 PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG); 238 239 static inline pte_t pte_mkspecial(pte_t pte) { return pte; } 240 241 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 242 { 243 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER | L_PTE_NONE; 244 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 245 return pte; 246 } 247 248 /* 249 * Encode and decode a swap entry. Swap entries are stored in the Linux 250 * page tables as follows: 251 * 252 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 253 * 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 0 254 * <--------------- offset ----------------------> < type -> 0 0 0 255 * 256 * This gives us up to 31 swap files and 64GB per swap file. Note that 257 * the offset field is always non-zero. 258 */ 259 #define __SWP_TYPE_SHIFT 3 260 #define __SWP_TYPE_BITS 5 261 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 262 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 263 264 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 265 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 266 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) 267 268 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 269 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 270 271 /* 272 * It is an error for the kernel to have more swap files than we can 273 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES 274 * is increased beyond what we presently support. 275 */ 276 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 277 278 /* 279 * Encode and decode a file entry. File entries are stored in the Linux 280 * page tables as follows: 281 * 282 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 283 * 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 0 284 * <----------------------- offset ------------------------> 1 0 0 285 */ 286 #define pte_file(pte) (pte_val(pte) & L_PTE_FILE) 287 #define pte_to_pgoff(x) (pte_val(x) >> 3) 288 #define pgoff_to_pte(x) __pte(((x) << 3) | L_PTE_FILE) 289 290 #define PTE_FILE_MAX_BITS 29 291 292 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ 293 /* FIXME: this is not correct */ 294 #define kern_addr_valid(addr) (1) 295 296 #include <asm-generic/pgtable.h> 297 298 /* 299 * We provide our own arch_get_unmapped_area to cope with VIPT caches. 300 */ 301 #define HAVE_ARCH_UNMAPPED_AREA 302 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN 303 304 /* 305 * remap a physical page `pfn' of size `size' with page protection `prot' 306 * into virtual address `from' 307 */ 308 #define io_remap_pfn_range(vma,from,pfn,size,prot) \ 309 remap_pfn_range(vma, from, pfn, size, prot) 310 311 #define pgtable_cache_init() do { } while (0) 312 313 #endif /* !__ASSEMBLY__ */ 314 315 #endif /* CONFIG_MMU */ 316 317 #endif /* _ASMARM_PGTABLE_H */ 318