LXR linux/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__
  49extern void __pte_error(const char *file, int line, pte_t);
  50extern void __pmd_error(const char *file, int line, pmd_t);
  51extern 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
  72extern pgprot_t         pgprot_user;
  73extern 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#define pgprot_stronglyordered(prot) \
 105        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 106
 107#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 108#define pgprot_dmacoherent(prot) \
 109        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
 110#define __HAVE_PHYS_MEM_ACCESS_PROT
 111struct file;
 112extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 113                                     unsigned long size, pgprot_t vma_prot);
 114#else
 115#define pgprot_dmacoherent(prot) \
 116        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
 117#endif
 118
 119#endif /* __ASSEMBLY__ */
 120
 121/*
 122 * The table below defines the page protection levels that we insert into our
 123 * Linux page table version.  These get translated into the best that the
 124 * architecture can perform.  Note that on most ARM hardware:
 125 *  1) We cannot do execute protection
 126 *  2) If we could do execute protection, then read is implied
 127 *  3) write implies read permissions
 128 */
 129#define __P000  __PAGE_NONE
 130#define __P001  __PAGE_READONLY
 131#define __P010  __PAGE_COPY
 132#define __P011  __PAGE_COPY
 133#define __P100  __PAGE_READONLY_EXEC
 134#define __P101  __PAGE_READONLY_EXEC
 135#define __P110  __PAGE_COPY_EXEC
 136#define __P111  __PAGE_COPY_EXEC
 137
 138#define __S000  __PAGE_NONE
 139#define __S001  __PAGE_READONLY
 140#define __S010  __PAGE_SHARED
 141#define __S011  __PAGE_SHARED
 142#define __S100  __PAGE_READONLY_EXEC
 143#define __S101  __PAGE_READONLY_EXEC
 144#define __S110  __PAGE_SHARED_EXEC
 145#define __S111  __PAGE_SHARED_EXEC
 146
 147#ifndef __ASSEMBLY__
 148/*
 149 * ZERO_PAGE is a global shared page that is always zero: used
 150 * for zero-mapped memory areas etc..
 151 */
 152extern struct page *empty_zero_page;
 153#define ZERO_PAGE(vaddr)        (empty_zero_page)
 154
 155
 156extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 157
 158/* to find an entry in a page-table-directory */
 159#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 160
 161#define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 162
 163/* to find an entry in a kernel page-table-directory */
 164#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 165
 166/*
 167 * The "pgd_xxx()" functions here are trivial for a folded two-level
 168 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 169 * into the pgd entry)
 170 */
 171#define pgd_none(pgd)           (0)
 172#define pgd_bad(pgd)            (0)
 173#define pgd_present(pgd)        (1)
 174#define pgd_clear(pgdp)         do { } while (0)
 175#define set_pgd(pgd,pgdp)       do { } while (0)
 176#define set_pud(pud,pudp)       do { } while (0)
 177
 178
 179/* Find an entry in the second-level page table.. */
 180#define pmd_offset(dir, addr)   ((pmd_t *)(dir))
 181
 182#define pmd_none(pmd)           (!pmd_val(pmd))
 183#define pmd_present(pmd)        (pmd_val(pmd))
 184#define pmd_bad(pmd)            (pmd_val(pmd) & 2)
 185
 186#define copy_pmd(pmdpd,pmdps)           \
 187        do {                            \
 188                pmdpd[0] = pmdps[0];    \
 189                pmdpd[1] = pmdps[1];    \
 190                flush_pmd_entry(pmdpd); \
 191        } while (0)
 192
 193#define pmd_clear(pmdp)                 \
 194        do {                            \
 195                pmdp[0] = __pmd(0);     \
 196                pmdp[1] = __pmd(0);     \
 197                clean_pmd_entry(pmdp);  \
 198        } while (0)
 199
 200static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 201{
 202        return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
 203}
 204
 205#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 206
 207/* we don't need complex calculations here as the pmd is folded into the pgd */
 208#define pmd_addr_end(addr,end)  (end)
 209
 210
 211#ifndef CONFIG_HIGHPTE
 212#define __pte_map(pmd)          pmd_page_vaddr(*(pmd))
 213#define __pte_unmap(pte)        do { } while (0)
 214#else
 215#define __pte_map(pmd)          (pte_t *)kmap_atomic(pmd_page(*(pmd)))
 216#define __pte_unmap(pte)        kunmap_atomic(pte)
 217#endif
 218
 219#define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 220
 221#define pte_offset_kernel(pmd,addr)     (pmd_page_vaddr(*(pmd)) + pte_index(addr))
 222
 223#define pte_offset_map(pmd,addr)        (__pte_map(pmd) + pte_index(addr))
 224#define pte_unmap(pte)                  __pte_unmap(pte)
 225
 226#define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 227#define pfn_pte(pfn,prot)       __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 228
 229#define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 230#define mk_pte(page,prot)       pfn_pte(page_to_pfn(page), prot)
 231
 232#define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
 233#define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
 234
 235#if __LINUX_ARM_ARCH__ < 6
 236static inline void __sync_icache_dcache(pte_t pteval)
 237{
 238}
 239#else
 240extern void __sync_icache_dcache(pte_t pteval);
 241#endif
 242
 243static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 244                              pte_t *ptep, pte_t pteval)
 245{
 246        if (addr >= TASK_SIZE)
 247                set_pte_ext(ptep, pteval, 0);
 248        else {
 249                __sync_icache_dcache(pteval);
 250                set_pte_ext(ptep, pteval, PTE_EXT_NG);
 251        }
 252}
 253
 254#define pte_none(pte)           (!pte_val(pte))
 255#define pte_present(pte)        (pte_val(pte) & L_PTE_PRESENT)
 256#define pte_write(pte)          (!(pte_val(pte) & L_PTE_RDONLY))
 257#define pte_dirty(pte)          (pte_val(pte) & L_PTE_DIRTY)
 258#define pte_young(pte)          (pte_val(pte) & L_PTE_YOUNG)
 259#define pte_exec(pte)           (!(pte_val(pte) & L_PTE_XN))
 260#define pte_special(pte)        (0)
 261
 262#define pte_present_user(pte) \
 263        ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
 264         (L_PTE_PRESENT | L_PTE_USER))
 265
 266#define PTE_BIT_FUNC(fn,op) \
 267static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 268
 269PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
 270PTE_BIT_FUNC(mkwrite,   &= ~L_PTE_RDONLY);
 271PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
 272PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
 273PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
 274PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 275
 276static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 277
 278static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 279{
 280        const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
 281        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 282        return pte;
 283}
 284
 285/*
 286 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 287 * page tables as follows:
 288 *
 289 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 290 *   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
 291 *   <--------------- offset --------------------> <- type --> 0 0 0
 292 *
 293 * This gives us up to 63 swap files and 32GB per swap file.  Note that
 294 * the offset field is always non-zero.
 295 */
 296#define __SWP_TYPE_SHIFT        3
 297#define __SWP_TYPE_BITS         6
 298#define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 299#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 300
 301#define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 302#define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 303#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 304
 305#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 306#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 307
 308/*
 309 * It is an error for the kernel to have more swap files than we can
 310 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 311 * is increased beyond what we presently support.
 312 */
 313#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 314
 315/*
 316 * Encode and decode a file entry.  File 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 ------------------------> 1 0 0
 322 */
 323#define pte_file(pte)           (pte_val(pte) & L_PTE_FILE)
 324#define pte_to_pgoff(x)         (pte_val(x) >> 3)
 325#define pgoff_to_pte(x)         __pte(((x) << 3) | L_PTE_FILE)
 326
 327#define PTE_FILE_MAX_BITS       29
 328
 329/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 330/* FIXME: this is not correct */
 331#define kern_addr_valid(addr)   (1)
 332
 333#include <asm-generic/pgtable.h>
 334
 335/*
 336 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 337 */
 338#define HAVE_ARCH_UNMAPPED_AREA
 339
 340/*
 341 * remap a physical page `pfn' of size `size' with page protection `prot'
 342 * into virtual address `from'
 343 */
 344#define io_remap_pfn_range(vma,from,pfn,size,prot) \
 345                remap_pfn_range(vma, from, pfn, size, prot)
 346
 347#define pgtable_cache_init() do { } while (0)
 348
 349void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
 350void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
 351
 352#endif /* !__ASSEMBLY__ */
 353
 354#endif /* CONFIG_MMU */
 355
 356#endif /* _ASMARM_PGTABLE_H */
 357