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-generic/4level-fixup.h>
  15 #include <asm/proc-fns.h>
  16
  17 #ifndef CONFIG_MMU
  18
  19 #include "pgtable-nommu.h"
  20
  21 #else
  22
  23 #include <asm/memory.h>
  24 #include <mach/vmalloc.h>
  25 #include <asm/pgtable-hwdef.h>
  26
  27 #include <asm/pgtable-2level.h>
  28
  29 /*
  30  * Just any arbitrary offset to the start of the vmalloc VM area: the
  31  * current 8MB value just means that there will be a 8MB "hole" after the
  32  * physical memory until the kernel virtual memory starts.  That means that
  33  * any out-of-bounds memory accesses will hopefully be caught.
  34  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  35  * area for the same reason. ;)
  36  *
  37  * Note that platforms may override VMALLOC_START, but they must provide
  38  * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  39  * which may not overlap IO space.
  40  */
  41 #ifndef VMALLOC_START
  42 #define VMALLOC_OFFSET          (8*1024*1024)
  43 #define VMALLOC_START           (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  44 #endif
  45
  46 #define LIBRARY_TEXT_START      0x0c000000
  47
  48 #ifndef __ASSEMBLY__
  49 extern void __pte_error(const char *file, int line, pte_t);
  50 extern void __pmd_error(const char *file, int line, pmd_t);
  51 extern void __pgd_error(const char *file, int line, pgd_t);
  52
  53 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte)
  54 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd)
  55 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd)
  56
  57 /*
  58  * This is the lowest virtual address we can permit any user space
  59  * mapping to be mapped at.  This is particularly important for
  60  * non-high vector CPUs.
  61  */
  62 #define FIRST_USER_ADDRESS      PAGE_SIZE
  63
  64 /*
  65  * The pgprot_* and protection_map entries will be fixed up in runtime
  66  * to include the cachable and bufferable bits based on memory policy,
  67  * as well as any architecture dependent bits like global/ASID and SMP
  68  * shared mapping bits.
  69  */
  70 #define _L_PTE_DEFAULT  L_PTE_PRESENT | L_PTE_YOUNG
  71
  72 extern pgprot_t         pgprot_user;
  73 extern pgprot_t         pgprot_kernel;
  74
  75 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
  76
  77 #define PAGE_NONE               _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
  78 #define PAGE_SHARED             _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
  79 #define PAGE_SHARED_EXEC        _MOD_PROT(pgprot_user, L_PTE_USER)
  80 #define PAGE_COPY               _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  81 #define PAGE_COPY_EXEC          _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  82 #define PAGE_READONLY           _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  83 #define PAGE_READONLY_EXEC      _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  84 #define PAGE_KERNEL             _MOD_PROT(pgprot_kernel, L_PTE_XN)
  85 #define PAGE_KERNEL_EXEC        pgprot_kernel
  86
  87 #define __PAGE_NONE             __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
  88 #define __PAGE_SHARED           __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
  89 #define __PAGE_SHARED_EXEC      __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
  90 #define __PAGE_COPY             __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  91 #define __PAGE_COPY_EXEC        __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  92 #define __PAGE_READONLY         __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  93 #define __PAGE_READONLY_EXEC    __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  94
  95 #define __pgprot_modify(prot,mask,bits)         \
  96         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
  97
  98 #define pgprot_noncached(prot) \
  99         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 100
 101 #define pgprot_writecombine(prot) \
 102         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
 103
 104 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 105 #define pgprot_dmacoherent(prot) \
 106         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
 107 #define __HAVE_PHYS_MEM_ACCESS_PROT
 108 struct file;
 109 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 110                                      unsigned long size, pgprot_t vma_prot);
 111 #else
 112 #define pgprot_dmacoherent(prot) \
 113         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
 114 #endif
 115
 116 #endif /* __ASSEMBLY__ */
 117
 118 /*
 119  * The table below defines the page protection levels that we insert into our
 120  * Linux page table version.  These get translated into the best that the
 121  * architecture can perform.  Note that on most ARM hardware:
 122  *  1) We cannot do execute protection
 123  *  2) If we could do execute protection, then read is implied
 124  *  3) write implies read permissions
 125  */
 126 #define __P000  __PAGE_NONE
 127 #define __P001  __PAGE_READONLY
 128 #define __P010  __PAGE_COPY
 129 #define __P011  __PAGE_COPY
 130 #define __P100  __PAGE_READONLY_EXEC
 131 #define __P101  __PAGE_READONLY_EXEC
 132 #define __P110  __PAGE_COPY_EXEC
 133 #define __P111  __PAGE_COPY_EXEC
 134
 135 #define __S000  __PAGE_NONE
 136 #define __S001  __PAGE_READONLY
 137 #define __S010  __PAGE_SHARED
 138 #define __S011  __PAGE_SHARED
 139 #define __S100  __PAGE_READONLY_EXEC
 140 #define __S101  __PAGE_READONLY_EXEC
 141 #define __S110  __PAGE_SHARED_EXEC
 142 #define __S111  __PAGE_SHARED_EXEC
 143
 144 #ifndef __ASSEMBLY__
 145 /*
 146  * ZERO_PAGE is a global shared page that is always zero: used
 147  * for zero-mapped memory areas etc..
 148  */
 149 extern struct page *empty_zero_page;
 150 #define ZERO_PAGE(vaddr)        (empty_zero_page)
 151
 152
 153 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 154
 155 /* to find an entry in a page-table-directory */
 156 #define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 157
 158 #define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 159
 160 /* to find an entry in a kernel page-table-directory */
 161 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 162
 163 /*
 164  * The "pgd_xxx()" functions here are trivial for a folded two-level
 165  * setup: the pgd is never bad, and a pmd always exists (as it's folded
 166  * into the pgd entry)
 167  */
 168 #define pgd_none(pgd)           (0)
 169 #define pgd_bad(pgd)            (0)
 170 #define pgd_present(pgd)        (1)
 171 #define pgd_clear(pgdp)         do { } while (0)
 172 #define set_pgd(pgd,pgdp)       do { } while (0)
 173 #define set_pud(pud,pudp)       do { } while (0)
 174
 175
 176 /* Find an entry in the second-level page table.. */
 177 #define pmd_offset(dir, addr)   ((pmd_t *)(dir))
 178
 179 #define pmd_none(pmd)           (!pmd_val(pmd))
 180 #define pmd_present(pmd)        (pmd_val(pmd))
 181 #define pmd_bad(pmd)            (pmd_val(pmd) & 2)
 182
 183 #define copy_pmd(pmdpd,pmdps)           \
 184         do {                            \
 185                 pmdpd[0] = pmdps[0];    \
 186                 pmdpd[1] = pmdps[1];    \
 187                 flush_pmd_entry(pmdpd); \
 188         } while (0)
 189
 190 #define pmd_clear(pmdp)                 \
 191         do {                            \
 192                 pmdp[0] = __pmd(0);     \
 193                 pmdp[1] = __pmd(0);     \
 194                 clean_pmd_entry(pmdp);  \
 195         } while (0)
 196
 197 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 198 {
 199         return __va(pmd_val(pmd) & PAGE_MASK);
 200 }
 201
 202 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
 203
 204 /* we don't need complex calculations here as the pmd is folded into the pgd */
 205 #define pmd_addr_end(addr,end)  (end)
 206
 207
 208 #ifndef CONFIG_HIGHPTE
 209 #define __pte_map(pmd)          pmd_page_vaddr(*(pmd))
 210 #define __pte_unmap(pte)        do { } while (0)
 211 #else
 212 #define __pte_map(pmd)          (pte_t *)kmap_atomic(pmd_page(*(pmd)))
 213 #define __pte_unmap(pte)        kunmap_atomic(pte)
 214 #endif
 215
 216 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 217
 218 #define pte_offset_kernel(pmd,addr)     (pmd_page_vaddr(*(pmd)) + pte_index(addr))
 219
 220 #define pte_offset_map(pmd,addr)        (__pte_map(pmd) + pte_index(addr))
 221 #define pte_unmap(pte)                  __pte_unmap(pte)
 222
 223 #define pte_pfn(pte)            (pte_val(pte) >> PAGE_SHIFT)
 224 #define pfn_pte(pfn,prot)       __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 225
 226 #define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 227 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page), prot)
 228
 229 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
 230 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
 231
 232 #if __LINUX_ARM_ARCH__ < 6
 233 static inline void __sync_icache_dcache(pte_t pteval)
 234 {
 235 }
 236 #else
 237 extern void __sync_icache_dcache(pte_t pteval);
 238 #endif
 239
 240 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 241                               pte_t *ptep, pte_t pteval)
 242 {
 243         if (addr >= TASK_SIZE)
 244                 set_pte_ext(ptep, pteval, 0);
 245         else {
 246                 __sync_icache_dcache(pteval);
 247                 set_pte_ext(ptep, pteval, PTE_EXT_NG);
 248         }
 249 }
 250
 251 #define pte_none(pte)           (!pte_val(pte))
 252 #define pte_present(pte)        (pte_val(pte) & L_PTE_PRESENT)
 253 #define pte_write(pte)          (!(pte_val(pte) & L_PTE_RDONLY))
 254 #define pte_dirty(pte)          (pte_val(pte) & L_PTE_DIRTY)
 255 #define pte_young(pte)          (pte_val(pte) & L_PTE_YOUNG)
 256 #define pte_exec(pte)           (!(pte_val(pte) & L_PTE_XN))
 257 #define pte_special(pte)        (0)
 258
 259 #define pte_present_user(pte) \
 260         ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
 261          (L_PTE_PRESENT | L_PTE_USER))
 262
 263 #define PTE_BIT_FUNC(fn,op) \
 264 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 265
 266 PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
 267 PTE_BIT_FUNC(mkwrite,   &= ~L_PTE_RDONLY);
 268 PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
 269 PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
 270 PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
 271 PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 272
 273 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 274
 275 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 276 {
 277         const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
 278         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 279         return pte;
 280 }
 281
 282 /*
 283  * Encode and decode a swap entry.  Swap entries are stored in the Linux
 284  * page tables as follows:
 285  *
 286  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 287  *   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
 288  *   <--------------- offset --------------------> <- type --> 0 0 0
 289  *
 290  * This gives us up to 63 swap files and 32GB per swap file.  Note that
 291  * the offset field is always non-zero.
 292  */
 293 #define __SWP_TYPE_SHIFT        3
 294 #define __SWP_TYPE_BITS         6
 295 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 296 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 297
 298 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 299 #define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 300 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 301
 302 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 303 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 304
 305 /*
 306  * It is an error for the kernel to have more swap files than we can
 307  * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 308  * is increased beyond what we presently support.
 309  */
 310 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 311
 312 /*
 313  * Encode and decode a file entry.  File entries are stored in the Linux
 314  * page tables as follows:
 315  *
 316  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 317  *   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
 318  *   <----------------------- offset ------------------------> 1 0 0
 319  */
 320 #define pte_file(pte)           (pte_val(pte) & L_PTE_FILE)
 321 #define pte_to_pgoff(x)         (pte_val(x) >> 3)
 322 #define pgoff_to_pte(x)         __pte(((x) << 3) | L_PTE_FILE)
 323
 324 #define PTE_FILE_MAX_BITS       29
 325
 326 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 327 /* FIXME: this is not correct */
 328 #define kern_addr_valid(addr)   (1)
 329
 330 #include <asm-generic/pgtable.h>
 331
 332 /*
 333  * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 334  */
 335 #define HAVE_ARCH_UNMAPPED_AREA
 336
 337 /*
 338  * remap a physical page `pfn' of size `size' with page protection `prot'
 339  * into virtual address `from'
 340  */
 341 #define io_remap_pfn_range(vma,from,pfn,size,prot) \
 342                 remap_pfn_range(vma, from, pfn, size, prot)
 343
 344 #define pgtable_cache_init() do { } while (0)
 345
 346 void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
 347 void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
 348
 349 #endif /* !__ASSEMBLY__ */
 350
 351 #endif /* CONFIG_MMU */
 352
 353 #endif /* _ASMARM_PGTABLE_H */