include/asm-arm/pgtable.h

   1 /*
   2  * linux/include/asm-arm/pgtable.h
   3  */
   4 #ifndef _ASMARM_PGTABLE_H
   5 #define _ASMARM_PGTABLE_H
   6
   7 #include <asm/arch/memory.h>
   8 #include <asm/proc-fns.h>
   9 #include <asm/system.h>
  10
  11 /*
  12  * PMD_SHIFT determines the size of the area a second-level page table can map
  13  * PGDIR_SHIFT determines what a third-level page table entry can map
  14  */
  15 #define PMD_SHIFT               20
  16 #define PGDIR_SHIFT             20
  17
  18 #define LIBRARY_TEXT_START      0x0c000000
  19
  20 #ifndef __ASSEMBLY__
  21 extern void __pte_error(const char *file, int line, unsigned long val);
  22 extern void __pmd_error(const char *file, int line, unsigned long val);
  23 extern void __pgd_error(const char *file, int line, unsigned long val);
  24
  25 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  26 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
  27 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
  28 #endif /* !__ASSEMBLY__ */
  29
  30 #define PMD_SIZE                (1UL << PMD_SHIFT)
  31 #define PMD_MASK                (~(PMD_SIZE-1))
  32 #define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  33 #define PGDIR_MASK              (~(PGDIR_SIZE-1))
  34
  35 #define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
  36
  37 /*
  38  * The table below defines the page protection levels that we insert into our
  39  * Linux page table version.  These get translated into the best that the
  40  * architecture can perform.  Note that on most ARM hardware:
  41  *  1) We cannot do execute protection
  42  *  2) If we could do execute protection, then read is implied
  43  *  3) write implies read permissions
  44  */
  45 #define __P000  PAGE_NONE
  46 #define __P001  PAGE_READONLY
  47 #define __P010  PAGE_COPY
  48 #define __P011  PAGE_COPY
  49 #define __P100  PAGE_READONLY
  50 #define __P101  PAGE_READONLY
  51 #define __P110  PAGE_COPY
  52 #define __P111  PAGE_COPY
  53
  54 #define __S000  PAGE_NONE
  55 #define __S001  PAGE_READONLY
  56 #define __S010  PAGE_SHARED
  57 #define __S011  PAGE_SHARED
  58 #define __S100  PAGE_READONLY
  59 #define __S101  PAGE_READONLY
  60 #define __S110  PAGE_SHARED
  61 #define __S111  PAGE_SHARED
  62
  63 #ifndef __ASSEMBLY__
  64 /*
  65  * ZERO_PAGE is a global shared page that is always zero: used
  66  * for zero-mapped memory areas etc..
  67  */
  68 extern struct page *empty_zero_page;
  69 #define ZERO_PAGE(vaddr)        (empty_zero_page)
  70
  71 /*
  72  * Handling allocation failures during page table setup.
  73  */
  74 extern void __handle_bad_pmd(pmd_t *pmd);
  75 extern void __handle_bad_pmd_kernel(pmd_t *pmd);
  76
  77 #define pte_none(pte)           (!pte_val(pte))
  78 #define pte_clear(ptep)         set_pte((ptep), __pte(0))
  79 #define pte_pagenr(pte)         ((unsigned long)(((pte_val(pte) - PHYS_OFFSET) >> PAGE_SHIFT)))
  80
  81 #define pmd_none(pmd)           (!pmd_val(pmd))
  82 #define pmd_clear(pmdp)         set_pmd(pmdp, __pmd(0))
  83
  84 /*
  85  * Permanent address of a page.
  86  */
  87 #define page_address(page)      ({ if (!(page)->virtual) BUG(); (page)->virtual; })
  88 #define pages_to_mb(x)          ((x) >> (20 - PAGE_SHIFT))
  89 #define pte_page(x)             (mem_map + pte_pagenr(x))
  90
  91 /*
  92  * Conversion functions: convert a page and protection to a page entry,
  93  * and a page entry and page directory to the page they refer to.
  94  */
  95 extern __inline__ pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
  96 {
  97         pte_t pte;
  98         pte_val(pte) = physpage | pgprot_val(pgprot);
  99         return pte;
 100 }
 101
 102 #define mk_pte(page,pgprot)                                     \
 103 ({                                                              \
 104         pte_t __pte;                                            \
 105         pte_val(__pte) = PHYS_OFFSET +                          \
 106                           (((page) - mem_map) << PAGE_SHIFT) +  \
 107                            pgprot_val(pgprot);                  \
 108         __pte;                                                  \
 109 })
 110
 111 /*
 112  * The "pgd_xxx()" functions here are trivial for a folded two-level
 113  * setup: the pgd is never bad, and a pmd always exists (as it's folded
 114  * into the pgd entry)
 115  */
 116 #define pgd_none(pgd)           (0)
 117 #define pgd_bad(pgd)            (0)
 118 #define pgd_present(pgd)        (1)
 119 #define pgd_clear(pgdp)
 120
 121 #define page_pte_prot(page,prot)        mk_pte(page, prot)
 122 #define page_pte(page)          mk_pte(page, __pgprot(0))
 123
 124 /* to find an entry in a page-table-directory */
 125 #define __pgd_offset(addr)      ((addr) >> PGDIR_SHIFT)
 126
 127 #define pgd_offset(mm, addr)    ((mm)->pgd+__pgd_offset(addr))
 128
 129 /* to find an entry in a kernel page-table-directory */
 130 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 131
 132 /* Find an entry in the second-level page table.. */
 133 #define pmd_offset(dir, addr)   ((pmd_t *)(dir))
 134
 135 /* Find an entry in the third-level page table.. */
 136 #define __pte_offset(addr)      (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 137 #define pte_offset(dir, addr)   ((pte_t *)pmd_page(*(dir)) + __pte_offset(addr))
 138
 139 #include <asm/proc/pgtable.h>
 140
 141 extern __inline__ pte_t pte_modify(pte_t pte, pgprot_t newprot)
 142 {
 143         pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
 144         return pte;
 145 }
 146
 147 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 148
 149 #define update_mmu_cache(vma,address,pte) do { } while (0)
 150
 151 /* Encode and decode a swap entry.
 152  *
 153  * We support up to 32GB of swap on 4k machines
 154  */
 155 #define SWP_TYPE(x)             (((x).val >> 2) & 0x7f)
 156 #define SWP_OFFSET(x)           ((x).val >> 9)
 157 #define SWP_ENTRY(type,offset)  ((swp_entry_t) { ((type) << 2) | ((offset) << 9) })
 158 #define pte_to_swp_entry(pte)   ((swp_entry_t) { pte_val(pte) })
 159 #define swp_entry_to_pte(swp)   ((pte_t) { (swp).val })
 160
 161 #define module_map              vmalloc
 162 #define module_unmap            vfree
 163
 164 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 165 #define PageSkip(page)          (machine_is_riscpc() && test_bit(PG_skip, &(page)->flags))
 166
 167 #define io_remap_page_range     remap_page_range
 168
 169 #endif /* !__ASSEMBLY__ */
 170
 171 #endif /* _ASMARM_PGTABLE_H */