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 <linux/config.h>
   8 #include <asm/arch/memory.h>
   9 #include <asm/proc-fns.h>
  10 #include <asm/system.h>
  11
  12 /*
  13  * PMD_SHIFT determines the size of the area a second-level page table can map
  14  * PGDIR_SHIFT determines what a third-level page table entry can map
  15  */
  16 #define PMD_SHIFT               20
  17 #define PGDIR_SHIFT             20
  18
  19 #define LIBRARY_TEXT_START      0x0c000000
  20
  21 #ifndef __ASSEMBLY__
  22 extern void __pte_error(const char *file, int line, unsigned long val);
  23 extern void __pmd_error(const char *file, int line, unsigned long val);
  24 extern void __pgd_error(const char *file, int line, unsigned long val);
  25
  26 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  27 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
  28 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
  29 #endif /* !__ASSEMBLY__ */
  30
  31 #define PMD_SIZE                (1UL << PMD_SHIFT)
  32 #define PMD_MASK                (~(PMD_SIZE-1))
  33 #define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  34 #define PGDIR_MASK              (~(PGDIR_SIZE-1))
  35
  36 #define FIRST_USER_PGD_NR       1
  37 #define USER_PTRS_PER_PGD       ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
  38
  39 /*
  40  * The table below defines the page protection levels that we insert into our
  41  * Linux page table version.  These get translated into the best that the
  42  * architecture can perform.  Note that on most ARM hardware:
  43  *  1) We cannot do execute protection
  44  *  2) If we could do execute protection, then read is implied
  45  *  3) write implies read permissions
  46  */
  47 #define __P000  PAGE_NONE
  48 #define __P001  PAGE_READONLY
  49 #define __P010  PAGE_COPY
  50 #define __P011  PAGE_COPY
  51 #define __P100  PAGE_READONLY
  52 #define __P101  PAGE_READONLY
  53 #define __P110  PAGE_COPY
  54 #define __P111  PAGE_COPY
  55
  56 #define __S000  PAGE_NONE
  57 #define __S001  PAGE_READONLY
  58 #define __S010  PAGE_SHARED
  59 #define __S011  PAGE_SHARED
  60 #define __S100  PAGE_READONLY
  61 #define __S101  PAGE_READONLY
  62 #define __S110  PAGE_SHARED
  63 #define __S111  PAGE_SHARED
  64
  65 #ifndef __ASSEMBLY__
  66 /*
  67  * ZERO_PAGE is a global shared page that is always zero: used
  68  * for zero-mapped memory areas etc..
  69  */
  70 extern struct page *empty_zero_page;
  71 #define ZERO_PAGE(vaddr)        (empty_zero_page)
  72
  73 /*
  74  * Handling allocation failures during page table setup.
  75  */
  76 extern void __handle_bad_pmd(pmd_t *pmd);
  77 extern void __handle_bad_pmd_kernel(pmd_t *pmd);
  78
  79 #define pte_none(pte)           (!pte_val(pte))
  80 #define pte_clear(ptep)         set_pte((ptep), __pte(0))
  81
  82 #ifndef CONFIG_DISCONTIGMEM
  83 #define pte_pagenr(pte)         ((unsigned long)(((pte_val(pte) - PHYS_OFFSET) >> PAGE_SHIFT)))
  84 #else
  85 /*
  86  * I'm not happy with this - we needlessly convert a physical address
  87  * to a virtual one, and then immediately back to a physical address,
  88  * which, if __va and __pa are expensive causes twice the expense for
  89  * zero gain. --rmk
  90  */
  91 #define pte_pagenr(pte)         MAP_NR(__va(pte_val(pte)))
  92 #endif
  93
  94 #define pmd_none(pmd)           (!pmd_val(pmd))
  95 #define pmd_clear(pmdp)         set_pmd(pmdp, __pmd(0))
  96
  97 /*
  98  * Permanent address of a page. We never have highmem, so this is trivial.
  99  */
 100 #define page_address(page)      ((page)->virtual)
 101 #define pages_to_mb(x)          ((x) >> (20 - PAGE_SHIFT))
 102 #define pte_page(x)             (mem_map + pte_pagenr(x))
 103
 104 /*
 105  * Conversion functions: convert a page and protection to a page entry,
 106  * and a page entry and page directory to the page they refer to.
 107  */
 108 extern __inline__ pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
 109 {
 110         pte_t pte;
 111         pte_val(pte) = physpage | pgprot_val(pgprot);
 112         return pte;
 113 }
 114
 115 #define mk_pte(page,pgprot)                             \
 116 ({                                                      \
 117         pte_t __pte;                                    \
 118         pte_val(__pte) = __pa(page_address(page)) +     \
 119                            pgprot_val(pgprot);          \
 120         __pte;                                          \
 121 })
 122
 123 /*
 124  * The "pgd_xxx()" functions here are trivial for a folded two-level
 125  * setup: the pgd is never bad, and a pmd always exists (as it's folded
 126  * into the pgd entry)
 127  */
 128 #define pgd_none(pgd)           (0)
 129 #define pgd_bad(pgd)            (0)
 130 #define pgd_present(pgd)        (1)
 131 #define pgd_clear(pgdp)
 132
 133 #define page_pte_prot(page,prot)        mk_pte(page, prot)
 134 #define page_pte(page)          mk_pte(page, __pgprot(0))
 135
 136 /* to find an entry in a page-table-directory */
 137 #define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 138 #define __pgd_offset(addr)      pgd_index(addr)
 139
 140 #define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))
 141
 142 /* to find an entry in a kernel page-table-directory */
 143 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 144
 145 /* Find an entry in the second-level page table.. */
 146 #define pmd_offset(dir, addr)   ((pmd_t *)(dir))
 147
 148 /* Find an entry in the third-level page table.. */
 149 #define __pte_offset(addr)      (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 150 #define pte_offset(dir, addr)   ((pte_t *)pmd_page(*(dir)) + __pte_offset(addr))
 151
 152 #include <asm/proc/pgtable.h>
 153
 154 extern __inline__ pte_t pte_modify(pte_t pte, pgprot_t newprot)
 155 {
 156         pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
 157         return pte;
 158 }
 159
 160 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 161
 162 #define update_mmu_cache(vma,address,pte) do { } while (0)
 163
 164 /* Encode and decode a swap entry.
 165  *
 166  * We support up to 32GB of swap on 4k machines
 167  */
 168 #define SWP_TYPE(x)             (((x).val >> 2) & 0x7f)
 169 #define SWP_OFFSET(x)           ((x).val >> 9)
 170 #define SWP_ENTRY(type,offset)  ((swp_entry_t) { ((type) << 2) | ((offset) << 9) })
 171 #define pte_to_swp_entry(pte)   ((swp_entry_t) { pte_val(pte) })
 172 #define swp_entry_to_pte(swp)   ((pte_t) { (swp).val })
 173
 174 #define module_map              vmalloc
 175 #define module_unmap            vfree
 176
 177 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 178 #define PageSkip(page)          (machine_is_riscpc() && test_bit(PG_skip, &(page)->flags))
 179
 180 #define io_remap_page_range     remap_page_range
 181
 182 #endif /* !__ASSEMBLY__ */
 183
 184 #endif /* _ASMARM_PGTABLE_H */