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 "pgtable-nommu.h"
  20
  21 #else
  22
  23 #include <asm-generic/pgtable-nopud.h>
  24 #include <asm/memory.h>
  25 #include <mach/vmalloc.h>
  26 #include <asm/pgtable-hwdef.h>
  27
  28 #ifdef CONFIG_ARM_LPAE
  29 #include <asm/pgtable-3level.h>
  30 #else
  31 #include <asm/pgtable-2level.h>
  32 #endif
  33
  34 /*
  35  * Just any arbitrary offset to the start of the vmalloc VM area: the
  36  * current 8MB value just means that there will be a 8MB "hole" after the
  37  * physical memory until the kernel virtual memory starts.  That means that
  38  * any out-of-bounds memory accesses will hopefully be caught.
  39  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  40  * area for the same reason. ;)
  41  *
  42  * Note that platforms may override VMALLOC_START, but they must provide
  43  * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  44  * which may not overlap IO space.
  45  */
  46 #ifndef VMALLOC_START
  47 #define VMALLOC_OFFSET          (8*1024*1024)
  48 #define VMALLOC_START           (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  49 #endif
  50
  51 #define LIBRARY_TEXT_START      0x0c000000
  52
  53 #ifndef __ASSEMBLY__
  54 extern void __pte_error(const char *file, int line, pte_t);
  55 extern void __pmd_error(const char *file, int line, pmd_t);
  56 extern void __pgd_error(const char *file, int line, pgd_t);
  57
  58 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte)
  59 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd)
  60 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd)
  61
  62 /*
  63  * This is the lowest virtual address we can permit any user space
  64  * mapping to be mapped at.  This is particularly important for
  65  * non-high vector CPUs.
  66  */
  67 #define FIRST_USER_ADDRESS      PAGE_SIZE
  68
  69 /*
  70  * The pgprot_* and protection_map entries will be fixed up in runtime
  71  * to include the cachable and bufferable bits based on memory policy,
  72  * as well as any architecture dependent bits like global/ASID and SMP
  73  * shared mapping bits.
  74  */
  75 #define _L_PTE_DEFAULT  L_PTE_PRESENT | L_PTE_YOUNG
  76
  77 extern pgprot_t         pgprot_user;
  78 extern pgprot_t         pgprot_kernel;
  79
  80 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
  81
  82 #define PAGE_NONE               _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
  83 #define PAGE_SHARED             _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
  84 #define PAGE_SHARED_EXEC        _MOD_PROT(pgprot_user, L_PTE_USER)
  85 #define PAGE_COPY               _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  86 #define PAGE_COPY_EXEC          _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  87 #define PAGE_READONLY           _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  88 #define PAGE_READONLY_EXEC      _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  89 #define PAGE_KERNEL             _MOD_PROT(pgprot_kernel, L_PTE_XN)
  90 #define PAGE_KERNEL_EXEC        pgprot_kernel
  91
  92 #define __PAGE_NONE             __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
  93 #define __PAGE_SHARED           __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
  94 #define __PAGE_SHARED_EXEC      __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
  95 #define __PAGE_COPY             __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  96 #define __PAGE_COPY_EXEC        __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  97 #define __PAGE_READONLY         __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  98 #define __PAGE_READONLY_EXEC    __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  99
 100 #define __pgprot_modify(prot,mask,bits)         \
 101         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
 102
 103 #define pgprot_noncached(prot) \
 104         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 105
 106 #define pgprot_writecombine(prot) \
 107         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
 108
 109 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 110 #define pgprot_dmacoherent(prot) \
 111         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
 112 #define __HAVE_PHYS_MEM_ACCESS_PROT
 113 struct file;
 114 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 115                                      unsigned long size, pgprot_t vma_prot);
 116 #else
 117 #define pgprot_dmacoherent(prot) \
 118         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
 119 #endif
 120
 121 #endif /* __ASSEMBLY__ */
 122
 123 /*
 124  * The table below defines the page protection levels that we insert into our
 125  * Linux page table version.  These get translated into the best that the
 126  * architecture can perform.  Note that on most ARM hardware:
 127  *  1) We cannot do execute protection
 128  *  2) If we could do execute protection, then read is implied
 129  *  3) write implies read permissions
 130  */
 131 #define __P000  __PAGE_NONE
 132 #define __P001  __PAGE_READONLY
 133 #define __P010  __PAGE_COPY
 134 #define __P011  __PAGE_COPY
 135 #define __P100  __PAGE_READONLY_EXEC
 136 #define __P101  __PAGE_READONLY_EXEC
 137 #define __P110  __PAGE_COPY_EXEC
 138 #define __P111  __PAGE_COPY_EXEC
 139
 140 #define __S000  __PAGE_NONE
 141 #define __S001  __PAGE_READONLY
 142 #define __S010  __PAGE_SHARED
 143 #define __S011  __PAGE_SHARED
 144 #define __S100  __PAGE_READONLY_EXEC
 145 #define __S101  __PAGE_READONLY_EXEC
 146 #define __S110  __PAGE_SHARED_EXEC
 147 #define __S111  __PAGE_SHARED_EXEC
 148
 149 #ifndef __ASSEMBLY__
 150 /*
 151  * ZERO_PAGE is a global shared page that is always zero: used
 152  * for zero-mapped memory areas etc..
 153  */
 154 extern struct page *empty_zero_page;
 155 #define ZERO_PAGE(vaddr)        (empty_zero_page)
 156
 157
 158 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 159
 160 /* to find an entry in a page-table-directory */
 161 #define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 162
 163 #define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 164
 165 /* to find an entry in a kernel page-table-directory */
 166 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 167
 168 #ifdef CONFIG_ARM_LPAE
 169
 170 #define pud_none(pud)           (!pud_val(pud))
 171 #define pud_bad(pud)            (!(pud_val(pud) & 2))
 172 #define pud_present(pud)        (pud_val(pud))
 173
 174 #define pud_clear(pudp)                 \
 175         do {                            \
 176                 *pudp = __pud(0);       \
 177                 clean_pmd_entry(pudp);  \
 178         } while (0)
 179
 180 #define set_pud(pudp, pud)              \
 181         do {                            \
 182                 *pudp = pud;            \
 183                 flush_pmd_entry(pudp);  \
 184         } while (0)
 185
 186 static inline pmd_t *pud_page_vaddr(pud_t pud)
 187 {
 188         return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
 189 }
 190
 191 #else   /* !CONFIG_ARM_LPAE */
 192
 193 /*
 194  * The "pud_xxx()" functions here are trivial when the pmd is folded into
 195  * the pud: the pud entry is never bad, always exists, and can't be set or
 196  * cleared.
 197  */
 198 #define pud_none(pud)           (0)
 199 #define pud_bad(pud)            (0)
 200 #define pud_present(pud)        (1)
 201 #define pud_clear(pudp)         do { } while (0)
 202 #define set_pud(pud,pudp)       do { } while (0)
 203
 204 #endif  /* CONFIG_ARM_LPAE */
 205
 206 /* Find an entry in the second-level page table.. */
 207 #ifdef CONFIG_ARM_LPAE
 208 #define pmd_index(addr)         (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 209 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 210 {
 211         return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
 212 }
 213 #else
 214 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 215 {
 216         return (pmd_t *)pud;
 217 }
 218 #endif
 219
 220 #define pmd_none(pmd)           (!pmd_val(pmd))
 221 #define pmd_present(pmd)        (pmd_val(pmd))
 222
 223 #ifdef CONFIG_ARM_LPAE
 224
 225 #define pmd_bad(pmd)            (!(pmd_val(pmd) & 2))
 226
 227 #define copy_pmd(pmdpd,pmdps)           \
 228         do {                            \
 229                 *pmdpd = *pmdps;        \
 230                 flush_pmd_entry(pmdpd); \
 231         } while (0)
 232
 233 #define pmd_clear(pmdp)                 \
 234         do {                            \
 235                 *pmdp = __pmd(0);       \
 236                 clean_pmd_entry(pmdp);  \
 237         } while (0)
 238
 239 #else   /* !CONFIG_ARM_LPAE */
 240
 241 #define pmd_bad(pmd)            (pmd_val(pmd) & 2)
 242
 243 #define copy_pmd(pmdpd,pmdps)           \
 244         do {                            \
 245                 pmdpd[0] = pmdps[0];    \
 246                 pmdpd[1] = pmdps[1];    \
 247                 flush_pmd_entry(pmdpd); \
 248         } while (0)
 249
 250 #define pmd_clear(pmdp)                 \
 251         do {                            \
 252                 pmdp[0] = __pmd(0);     \
 253                 pmdp[1] = __pmd(0);     \
 254                 clean_pmd_entry(pmdp);  \
 255         } while (0)
 256
 257 #endif  /* CONFIG_ARM_LPAE */
 258
 259 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 260 {
 261         return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
 262 }
 263
 264 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 265
 266 #ifndef CONFIG_HIGHPTE
 267 #define __pte_map(pmd)          pmd_page_vaddr(*(pmd))
 268 #define __pte_unmap(pte)        do { } while (0)
 269 #else
 270 #define __pte_map(pmd)          (pte_t *)kmap_atomic(pmd_page(*(pmd)))
 271 #define __pte_unmap(pte)        kunmap_atomic(pte)
 272 #endif
 273
 274 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 275
 276 #define pte_offset_kernel(pmd,addr)     (pmd_page_vaddr(*(pmd)) + pte_index(addr))
 277
 278 #define pte_offset_map(pmd,addr)        (__pte_map(pmd) + pte_index(addr))
 279 #define pte_unmap(pte)                  __pte_unmap(pte)
 280
 281 #define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 282 #define pfn_pte(pfn,prot)       __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 283
 284 #define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 285 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page), prot)
 286
 287 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
 288
 289 #ifdef CONFIG_ARM_LPAE
 290 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
 291 #else
 292 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
 293 #endif
 294
 295 #if __LINUX_ARM_ARCH__ < 6
 296 static inline void __sync_icache_dcache(pte_t pteval)
 297 {
 298 }
 299 #else
 300 extern void __sync_icache_dcache(pte_t pteval);
 301 #endif
 302
 303 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 304                               pte_t *ptep, pte_t pteval)
 305 {
 306         if (addr >= TASK_SIZE)
 307                 set_pte_ext(ptep, pteval, 0);
 308         else {
 309                 __sync_icache_dcache(pteval);
 310                 set_pte_ext(ptep, pteval, PTE_EXT_NG);
 311         }
 312 }
 313
 314 #define pte_none(pte)           (!pte_val(pte))
 315 #define pte_present(pte)        (pte_val(pte) & L_PTE_PRESENT)
 316 #define pte_write(pte)          (!(pte_val(pte) & L_PTE_RDONLY))
 317 #define pte_dirty(pte)          (pte_val(pte) & L_PTE_DIRTY)
 318 #define pte_young(pte)          (pte_val(pte) & L_PTE_YOUNG)
 319 #define pte_exec(pte)           (!(pte_val(pte) & L_PTE_XN))
 320 #define pte_special(pte)        (0)
 321
 322 #define pte_present_user(pte) \
 323         ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
 324          (L_PTE_PRESENT | L_PTE_USER))
 325
 326 #define PTE_BIT_FUNC(fn,op) \
 327 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 328
 329 PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
 330 PTE_BIT_FUNC(mkwrite,   &= ~L_PTE_RDONLY);
 331 PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
 332 PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
 333 PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
 334 PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 335
 336 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 337
 338 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 339 {
 340         const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
 341         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 342         return pte;
 343 }
 344
 345 /*
 346  * Encode and decode a swap entry.  Swap entries are stored in the Linux
 347  * page tables as follows:
 348  *
 349  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 350  *   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
 351  *   <--------------- offset --------------------> <- type --> 0 0 0
 352  *
 353  * This gives us up to 63 swap files and 32GB per swap file.  Note that
 354  * the offset field is always non-zero.
 355  */
 356 #define __SWP_TYPE_SHIFT        3
 357 #define __SWP_TYPE_BITS         6
 358 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 359 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 360
 361 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 362 #define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 363 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 364
 365 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 366 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 367
 368 /*
 369  * It is an error for the kernel to have more swap files than we can
 370  * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 371  * is increased beyond what we presently support.
 372  */
 373 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 374
 375 /*
 376  * Encode and decode a file entry.  File entries are stored in the Linux
 377  * page tables as follows:
 378  *
 379  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 380  *   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
 381  *   <----------------------- offset ------------------------> 1 0 0
 382  */
 383 #define pte_file(pte)           (pte_val(pte) & L_PTE_FILE)
 384 #define pte_to_pgoff(x)         (pte_val(x) >> 3)
 385 #define pgoff_to_pte(x)         __pte(((x) << 3) | L_PTE_FILE)
 386
 387 #define PTE_FILE_MAX_BITS       29
 388
 389 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 390 /* FIXME: this is not correct */
 391 #define kern_addr_valid(addr)   (1)
 392
 393 #include <asm-generic/pgtable.h>
 394
 395 /*
 396  * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 397  */
 398 #define HAVE_ARCH_UNMAPPED_AREA
 399
 400 /*
 401  * remap a physical page `pfn' of size `size' with page protection `prot'
 402  * into virtual address `from'
 403  */
 404 #define io_remap_pfn_range(vma,from,pfn,size,prot) \
 405                 remap_pfn_range(vma, from, pfn, size, prot)
 406
 407 #define pgtable_cache_init() do { } while (0)
 408
 409 void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
 410 void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
 411
 412 #endif /* !__ASSEMBLY__ */
 413
 414 #endif /* CONFIG_MMU */
 415
 416 #endif /* _ASMARM_PGTABLE_H */