arch/arm/include/asm/pgtable.h

   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 */