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/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 <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__
  48extern void __pte_error(const char *file, int line, pte_t);
  49extern void __pmd_error(const char *file, int line, pmd_t);
  50extern 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
  62
  63/*
  64 * The pgprot_* and protection_map entries will be fixed up in runtime
  65 * to include the cachable and bufferable bits based on memory policy,
  66 * as well as any architecture dependent bits like global/ASID and SMP
  67 * shared mapping bits.
  68 */
  69#define _L_PTE_DEFAULT  L_PTE_PRESENT | L_PTE_YOUNG
  70
  71extern pgprot_t         pgprot_user;
  72extern pgprot_t         pgprot_kernel;
  73
  74#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
  75
  76#define PAGE_NONE               _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
  77#define PAGE_SHARED             _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
  78#define PAGE_SHARED_EXEC        _MOD_PROT(pgprot_user, L_PTE_USER)
  79#define PAGE_COPY               _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  80#define PAGE_COPY_EXEC          _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  81#define PAGE_READONLY           _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  82#define PAGE_READONLY_EXEC      _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
  83#define PAGE_KERNEL             _MOD_PROT(pgprot_kernel, L_PTE_XN)
  84#define PAGE_KERNEL_EXEC        pgprot_kernel
  85
  86#define __PAGE_NONE             __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
  87#define __PAGE_SHARED           __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
  88#define __PAGE_SHARED_EXEC      __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
  89#define __PAGE_COPY             __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  90#define __PAGE_COPY_EXEC        __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  91#define __PAGE_READONLY         __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
  92#define __PAGE_READONLY_EXEC    __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
  93
  94#define __pgprot_modify(prot,mask,bits)         \
  95        __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
  96
  97#define pgprot_noncached(prot) \
  98        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
  99
 100#define pgprot_writecombine(prot) \
 101        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
 102
 103#define pgprot_stronglyordered(prot) \
 104        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
 105
 106#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
 107#define pgprot_dmacoherent(prot) \
 108        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
 109#define __HAVE_PHYS_MEM_ACCESS_PROT
 110struct file;
 111extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 112                                     unsigned long size, pgprot_t vma_prot);
 113#else
 114#define pgprot_dmacoherent(prot) \
 115        __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
 116#endif
 117
 118#endif /* __ASSEMBLY__ */
 119
 120/*
 121 * The table below defines the page protection levels that we insert into our
 122 * Linux page table version.  These get translated into the best that the
 123 * architecture can perform.  Note that on most ARM hardware:
 124 *  1) We cannot do execute protection
 125 *  2) If we could do execute protection, then read is implied
 126 *  3) write implies read permissions
 127 */
 128#define __P000  __PAGE_NONE
 129#define __P001  __PAGE_READONLY
 130#define __P010  __PAGE_COPY
 131#define __P011  __PAGE_COPY
 132#define __P100  __PAGE_READONLY_EXEC
 133#define __P101  __PAGE_READONLY_EXEC
 134#define __P110  __PAGE_COPY_EXEC
 135#define __P111  __PAGE_COPY_EXEC
 136
 137#define __S000  __PAGE_NONE
 138#define __S001  __PAGE_READONLY
 139#define __S010  __PAGE_SHARED
 140#define __S011  __PAGE_SHARED
 141#define __S100  __PAGE_READONLY_EXEC
 142#define __S101  __PAGE_READONLY_EXEC
 143#define __S110  __PAGE_SHARED_EXEC
 144#define __S111  __PAGE_SHARED_EXEC
 145
 146#ifndef __ASSEMBLY__
 147/*
 148 * ZERO_PAGE is a global shared page that is always zero: used
 149 * for zero-mapped memory areas etc..
 150 */
 151extern struct page *empty_zero_page;
 152#define ZERO_PAGE(vaddr)        (empty_zero_page)
 153
 154
 155extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 156
 157/* to find an entry in a page-table-directory */
 158#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 159
 160#define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 161
 162/* to find an entry in a kernel page-table-directory */
 163#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 164
 165#define pmd_none(pmd)           (!pmd_val(pmd))
 166#define pmd_present(pmd)        (pmd_val(pmd))
 167
 168static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 169{
 170        return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
 171}
 172
 173#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 174
 175#ifndef CONFIG_HIGHPTE
 176#define __pte_map(pmd)          pmd_page_vaddr(*(pmd))
 177#define __pte_unmap(pte)        do { } while (0)
 178#else
 179#define __pte_map(pmd)          (pte_t *)kmap_atomic(pmd_page(*(pmd)))
 180#define __pte_unmap(pte)        kunmap_atomic(pte)
 181#endif
 182
 183#define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 184
 185#define pte_offset_kernel(pmd,addr)     (pmd_page_vaddr(*(pmd)) + pte_index(addr))
 186
 187#define pte_offset_map(pmd,addr)        (__pte_map(pmd) + pte_index(addr))
 188#define pte_unmap(pte)                  __pte_unmap(pte)
 189
 190#define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 191#define pfn_pte(pfn,prot)       __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 192
 193#define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 194#define mk_pte(page,prot)       pfn_pte(page_to_pfn(page), prot)
 195
 196#define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
 197
 198#if __LINUX_ARM_ARCH__ < 6
 199static inline void __sync_icache_dcache(pte_t pteval)
 200{
 201}
 202#else
 203extern void __sync_icache_dcache(pte_t pteval);
 204#endif
 205
 206static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 207                              pte_t *ptep, pte_t pteval)
 208{
 209        if (addr >= TASK_SIZE)
 210                set_pte_ext(ptep, pteval, 0);
 211        else {
 212                __sync_icache_dcache(pteval);
 213                set_pte_ext(ptep, pteval, PTE_EXT_NG);
 214        }
 215}
 216
 217#define pte_none(pte)           (!pte_val(pte))
 218#define pte_present(pte)        (pte_val(pte) & L_PTE_PRESENT)
 219#define pte_write(pte)          (!(pte_val(pte) & L_PTE_RDONLY))
 220#define pte_dirty(pte)          (pte_val(pte) & L_PTE_DIRTY)
 221#define pte_young(pte)          (pte_val(pte) & L_PTE_YOUNG)
 222#define pte_exec(pte)           (!(pte_val(pte) & L_PTE_XN))
 223#define pte_special(pte)        (0)
 224
 225#define pte_present_user(pte) \
 226        ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
 227         (L_PTE_PRESENT | L_PTE_USER))
 228
 229#define PTE_BIT_FUNC(fn,op) \
 230static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 231
 232PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
 233PTE_BIT_FUNC(mkwrite,   &= ~L_PTE_RDONLY);
 234PTE_BIT_FUNC(mkclean,   &= ~L_PTE_DIRTY);
 235PTE_BIT_FUNC(mkdirty,   |= L_PTE_DIRTY);
 236PTE_BIT_FUNC(mkold,     &= ~L_PTE_YOUNG);
 237PTE_BIT_FUNC(mkyoung,   |= L_PTE_YOUNG);
 238
 239static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 240
 241static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 242{
 243        const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
 244        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 245        return pte;
 246}
 247
 248/*
 249 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 250 * page tables as follows:
 251 *
 252 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 253 *   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
 254 *   <--------------- offset --------------------> <- type --> 0 0 0
 255 *
 256 * This gives us up to 63 swap files and 32GB per swap file.  Note that
 257 * the offset field is always non-zero.
 258 */
 259#define __SWP_TYPE_SHIFT        3
 260#define __SWP_TYPE_BITS         6
 261#define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 262#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 263
 264#define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 265#define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 266#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 267
 268#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 269#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 270
 271/*
 272 * It is an error for the kernel to have more swap files than we can
 273 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 274 * is increased beyond what we presently support.
 275 */
 276#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 277
 278/*
 279 * Encode and decode a file entry.  File entries are stored in the Linux
 280 * page tables as follows:
 281 *
 282 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 283 *   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
 284 *   <----------------------- offset ------------------------> 1 0 0
 285 */
 286#define pte_file(pte)           (pte_val(pte) & L_PTE_FILE)
 287#define pte_to_pgoff(x)         (pte_val(x) >> 3)
 288#define pgoff_to_pte(x)         __pte(((x) << 3) | L_PTE_FILE)
 289
 290#define PTE_FILE_MAX_BITS       29
 291
 292/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 293/* FIXME: this is not correct */
 294#define kern_addr_valid(addr)   (1)
 295
 296#include <asm-generic/pgtable.h>
 297
 298/*
 299 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
 300 */
 301#define HAVE_ARCH_UNMAPPED_AREA
 302#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 303
 304/*
 305 * remap a physical page `pfn' of size `size' with page protection `prot'
 306 * into virtual address `from'
 307 */
 308#define io_remap_pfn_range(vma,from,pfn,size,prot) \
 309                remap_pfn_range(vma, from, pfn, size, prot)
 310
 311#define pgtable_cache_init() do { } while (0)
 312
 313#endif /* !__ASSEMBLY__ */
 314
 315#endif /* CONFIG_MMU */
 316
 317#endif /* _ASMARM_PGTABLE_H */
 318