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 #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 * 2)
  62
  63 /*
  64  * Use TASK_SIZE as the ceiling argument for free_pgtables() and
  65  * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
  66  * page shared between user and kernel).
  67  */
  68 #ifdef CONFIG_ARM_LPAE
  69 #define USER_PGTABLES_CEILING   TASK_SIZE
  70 #endif
  71
  72 /*
  73  * The pgprot_* and protection_map entries will be fixed up in runtime
  74  * to include the cachable and bufferable bits based on memory policy,
  75  * as well as any architecture dependent bits like global/ASID and SMP
  76  * shared mapping bits.
  77  */
  78 #define _L_PTE_DEFAULT  L_PTE_PRESENT | L_PTE_YOUNG
  79
  80 extern pgprot_t         pgprot_user;
  81 extern pgprot_t         pgprot_kernel;
  82 extern pgprot_t         pgprot_hyp_device;
  83 extern pgprot_t         pgprot_s2;
  84 extern pgprot_t         pgprot_s2_device;
  85
  86 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
  87
  88 #define PAGE_NONE               _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
  89 #define PAGE_SHARED             _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
  90 #define PAGE_SHARED_EXEC        _MOD_PROT(pgprot_user, L_PTE_USER)
  91 #define PAGE_COPY               _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  92 #define PAGE_COPY_EXEC          _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  93 #define PAGE_READONLY           _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  94 #define PAGE_READONLY_EXEC      _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  95 #define PAGE_KERNEL             _MOD_PROT(pgprot_kernel, L_PTE_XN)
  96 #define PAGE_KERNEL_EXEC        pgprot_kernel
  97 #define PAGE_HYP                _MOD_PROT(pgprot_kernel, L_PTE_HYP)
  98 #define PAGE_HYP_DEVICE         _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
  99 #define PAGE_S2                 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY)
 100 #define PAGE_S2_DEVICE          _MOD_PROT(pgprot_s2_device, L_PTE_USER | L_PTE_S2_RDONLY)
 101
 102 #define __PAGE_NONE             __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
 103 #define __PAGE_SHARED           __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
 104 #define __PAGE_SHARED_EXEC      __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
 105 #define __PAGE_COPY             __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
 106 #define __PAGE_COPY_EXEC        __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
 107 #define __PAGE_READONLY         __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
 108 #define __PAGE_READONLY_EXEC    __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
 109
 110 #define __pgprot_modify(prot,mask,bits)         \
 111         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
 112
 113 #define pgprot_noncached(prot) \
 114         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 115
 116 #define pgprot_writecombine(prot) \
 117         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
 118
 119 #define pgprot_stronglyordered(prot) \
 120         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 121
 122 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 123 #define pgprot_dmacoherent(prot) \
 124         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
 125 #define __HAVE_PHYS_MEM_ACCESS_PROT
 126 struct file;
 127 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 128                                      unsigned long size, pgprot_t vma_prot);
 129 #else
 130 #define pgprot_dmacoherent(prot) \
 131         __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
 132 #endif
 133
 134 #endif /* __ASSEMBLY__ */
 135
 136 /*
 137  * The table below defines the page protection levels that we insert into our
 138  * Linux page table version.  These get translated into the best that the
 139  * architecture can perform.  Note that on most ARM hardware:
 140  *  1) We cannot do execute protection
 141  *  2) If we could do execute protection, then read is implied
 142  *  3) write implies read permissions
 143  */
 144 #define __P000  __PAGE_NONE
 145 #define __P001  __PAGE_READONLY
 146 #define __P010  __PAGE_COPY
 147 #define __P011  __PAGE_COPY
 148 #define __P100  __PAGE_READONLY_EXEC
 149 #define __P101  __PAGE_READONLY_EXEC
 150 #define __P110  __PAGE_COPY_EXEC
 151 #define __P111  __PAGE_COPY_EXEC
 152
 153 #define __S000  __PAGE_NONE
 154 #define __S001  __PAGE_READONLY
 155 #define __S010  __PAGE_SHARED
 156 #define __S011  __PAGE_SHARED
 157 #define __S100  __PAGE_READONLY_EXEC
 158 #define __S101  __PAGE_READONLY_EXEC
 159 #define __S110  __PAGE_SHARED_EXEC
 160 #define __S111  __PAGE_SHARED_EXEC
 161
 162 #ifndef __ASSEMBLY__
 163 /*
 164  * ZERO_PAGE is a global shared page that is always zero: used
 165  * for zero-mapped memory areas etc..
 166  */
 167 extern struct page *empty_zero_page;
 168 #define ZERO_PAGE(vaddr)        (empty_zero_page)
 169
 170
 171 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 172
 173 /* to find an entry in a page-table-directory */
 174 #define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 175
 176 #define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 177
 178 /* to find an entry in a kernel page-table-directory */
 179 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 180
 181 #define pmd_none(pmd)           (!pmd_val(pmd))
 182 #define pmd_present(pmd)        (pmd_val(pmd))
 183
 184 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 185 {
 186         return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
 187 }
 188
 189 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 190
 191 #ifndef CONFIG_HIGHPTE
 192 #define __pte_map(pmd)          pmd_page_vaddr(*(pmd))
 193 #define __pte_unmap(pte)        do { } while (0)
 194 #else
 195 #define __pte_map(pmd)          (pte_t *)kmap_atomic(pmd_page(*(pmd)))
 196 #define __pte_unmap(pte)        kunmap_atomic(pte)
 197 #endif
 198
 199 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 200
 201 #define pte_offset_kernel(pmd,addr)     (pmd_page_vaddr(*(pmd)) + pte_index(addr))
 202
 203 #define pte_offset_map(pmd,addr)        (__pte_map(pmd) + pte_index(addr))
 204 #define pte_unmap(pte)                  __pte_unmap(pte)
 205
 206 #define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 207 #define pfn_pte(pfn,prot)       __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 208
 209 #define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 210 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page), prot)
 211
 212 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
 213
 214 #define pte_isset(pte, val)     ((u32)(val) == (val) ? pte_val(pte) & (val) \
 215                                                 : !!(pte_val(pte) & (val)))
 216 #define pte_isclear(pte, val)   (!(pte_val(pte) & (val)))
 217
 218 #define pte_none(pte)           (!pte_val(pte))
 219 #define pte_present(pte)        (pte_isset((pte), L_PTE_PRESENT))
 220 #define pte_write(pte)          (pte_isclear((pte), L_PTE_RDONLY))
 221 #define pte_dirty(pte)          (pte_isset((pte), L_PTE_DIRTY))
 222 #define pte_young(pte)          (pte_isset((pte), L_PTE_YOUNG))
 223 #define pte_exec(pte)           (pte_isclear((pte), L_PTE_XN))
 224 #define pte_special(pte)        (0)
 225
 226 #define pte_present_user(pte)  (pte_present(pte) && (pte_val(pte) & L_PTE_USER))
 227
 228 #if __LINUX_ARM_ARCH__ < 6
 229 static inline void __sync_icache_dcache(pte_t pteval)
 230 {
 231 }
 232 #else
 233 extern void __sync_icache_dcache(pte_t pteval);
 234 #endif
 235
 236 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 237                               pte_t *ptep, pte_t pteval)
 238 {
 239         unsigned long ext = 0;
 240
 241         if (addr < TASK_SIZE && pte_present_user(pteval)) {
 242                 __sync_icache_dcache(pteval);
 243                 ext |= PTE_EXT_NG;
 244         }
 245
 246         set_pte_ext(ptep, pteval, ext);
 247 }
 248
 249 #define PTE_BIT_FUNC(fn,op) \
 250 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 251
 252 PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
 253 PTE_BIT_FUNC(mkwrite,   &= ~L_PTE_RDONLY);
 254 PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
 255 PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
 256 PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
 257 PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 258
 259 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 260
 261 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 262 {
 263         const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
 264                 L_PTE_NONE | L_PTE_VALID;
 265         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 266         return pte;
 267 }
 268
 269 /*
 270  * Encode and decode a swap entry.  Swap entries are stored in the Linux
 271  * page tables as follows:
 272  *
 273  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 274  *   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
 275  *   <--------------- offset ----------------------> < type -> 0 0 0
 276  *
 277  * This gives us up to 31 swap files and 64GB per swap file.  Note that
 278  * the offset field is always non-zero.
 279  */
 280 #define __SWP_TYPE_SHIFT        3
 281 #define __SWP_TYPE_BITS         5
 282 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 283 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 284
 285 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 286 #define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 287 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 288
 289 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 290 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 291
 292 /*
 293  * It is an error for the kernel to have more swap files than we can
 294  * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 295  * is increased beyond what we presently support.
 296  */
 297 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 298
 299 /*
 300  * Encode and decode a file entry.  File entries are stored in the Linux
 301  * page tables as follows:
 302  *
 303  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 304  *   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
 305  *   <----------------------- offset ------------------------> 1 0 0
 306  */
 307 #define pte_file(pte)           (pte_val(pte) & L_PTE_FILE)
 308 #define pte_to_pgoff(x)         (pte_val(x) >> 3)
 309 #define pgoff_to_pte(x)         __pte(((x) << 3) | L_PTE_FILE)
 310
 311 #define PTE_FILE_MAX_BITS       29
 312
 313 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 314 /* FIXME: this is not correct */
 315 #define kern_addr_valid(addr)   (1)
 316
 317 #include <asm-generic/pgtable.h>
 318
 319 /*
 320  * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 321  */
 322 #define HAVE_ARCH_UNMAPPED_AREA
 323 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 324
 325 /*
 326  * remap a physical page `pfn' of size `size' with page protection `prot'
 327  * into virtual address `from'
 328  */
 329 #define io_remap_pfn_range(vma,from,pfn,size,prot) \
 330                 remap_pfn_range(vma, from, pfn, size, prot)
 331
 332 #define pgtable_cache_init() do { } while (0)
 333
 334 #endif /* !__ASSEMBLY__ */
 335
 336 #endif /* CONFIG_MMU */
 337
 338 #endif /* _ASMARM_PGTABLE_H */