include/asm-generic/pgtable.h

   1 #ifndef _ASM_GENERIC_PGTABLE_H
   2 #define _ASM_GENERIC_PGTABLE_H
   3
   4 #ifndef __HAVE_ARCH_PTEP_ESTABLISH
   5 /*
   6  * Establish a new mapping:
   7  *  - flush the old one
   8  *  - update the page tables
   9  *  - inform the TLB about the new one
  10  *
  11  * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock.
  12  *
  13  * Note: the old pte is known to not be writable, so we don't need to
  14  * worry about dirty bits etc getting lost.
  15  */
  16 #ifndef __HAVE_ARCH_SET_PTE_ATOMIC
  17 #define ptep_establish(__vma, __address, __ptep, __entry)               \
  18 do {                                                                    \
  19         set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);       \
  20         flush_tlb_page(__vma, __address);                               \
  21 } while (0)
  22 #else /* __HAVE_ARCH_SET_PTE_ATOMIC */
  23 #define ptep_establish(__vma, __address, __ptep, __entry)               \
  24 do {                                                                    \
  25         set_pte_atomic(__ptep, __entry);                                \
  26         flush_tlb_page(__vma, __address);                               \
  27 } while (0)
  28 #endif /* __HAVE_ARCH_SET_PTE_ATOMIC */
  29 #endif
  30
  31 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  32 /*
  33  * Largely same as above, but only sets the access flags (dirty,
  34  * accessed, and writable). Furthermore, we know it always gets set
  35  * to a "more permissive" setting, which allows most architectures
  36  * to optimize this.
  37  */
  38 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
  39 do {                                                                      \
  40         set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);         \
  41         flush_tlb_page(__vma, __address);                                 \
  42 } while (0)
  43 #endif
  44
  45 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  46 #define ptep_test_and_clear_young(__vma, __address, __ptep)             \
  47 ({                                                                      \
  48         pte_t __pte = *(__ptep);                                        \
  49         int r = 1;                                                      \
  50         if (!pte_young(__pte))                                          \
  51                 r = 0;                                                  \
  52         else                                                            \
  53                 set_pte_at((__vma)->vm_mm, (__address),                 \
  54                            (__ptep), pte_mkold(__pte));                 \
  55         r;                                                              \
  56 })
  57 #endif
  58
  59 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  60 #define ptep_clear_flush_young(__vma, __address, __ptep)                \
  61 ({                                                                      \
  62         int __young;                                                    \
  63         __young = ptep_test_and_clear_young(__vma, __address, __ptep);  \
  64         if (__young)                                                    \
  65                 flush_tlb_page(__vma, __address);                       \
  66         __young;                                                        \
  67 })
  68 #endif
  69
  70 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
  71 #define ptep_test_and_clear_dirty(__vma, __address, __ptep)             \
  72 ({                                                                      \
  73         pte_t __pte = *__ptep;                                          \
  74         int r = 1;                                                      \
  75         if (!pte_dirty(__pte))                                          \
  76                 r = 0;                                                  \
  77         else                                                            \
  78                 set_pte_at((__vma)->vm_mm, (__address), (__ptep),       \
  79                            pte_mkclean(__pte));                         \
  80         r;                                                              \
  81 })
  82 #endif
  83
  84 #ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
  85 #define ptep_clear_flush_dirty(__vma, __address, __ptep)                \
  86 ({                                                                      \
  87         int __dirty;                                                    \
  88         __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep);  \
  89         if (__dirty)                                                    \
  90                 flush_tlb_page(__vma, __address);                       \
  91         __dirty;                                                        \
  92 })
  93 #endif
  94
  95 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
  96 #define ptep_get_and_clear(__mm, __address, __ptep)                     \
  97 ({                                                                      \
  98         pte_t __pte = *(__ptep);                                        \
  99         pte_clear((__mm), (__address), (__ptep));                       \
 100         __pte;                                                          \
 101 })
 102 #endif
 103
 104 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
 105 #define ptep_get_and_clear_full(__mm, __address, __ptep, __full)        \
 106 ({                                                                      \
 107         pte_t __pte;                                                    \
 108         __pte = ptep_get_and_clear((__mm), (__address), (__ptep));      \
 109         __pte;                                                          \
 110 })
 111 #endif
 112
 113 #ifndef __HAVE_ARCH_PTE_CLEAR_FULL
 114 #define pte_clear_full(__mm, __address, __ptep, __full)                 \
 115 do {                                                                    \
 116         pte_clear((__mm), (__address), (__ptep));                       \
 117 } while (0)
 118 #endif
 119
 120 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 121 #define ptep_clear_flush(__vma, __address, __ptep)                      \
 122 ({                                                                      \
 123         pte_t __pte;                                                    \
 124         __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
 125         flush_tlb_page(__vma, __address);                               \
 126         __pte;                                                          \
 127 })
 128 #endif
 129
 130 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
 131 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 132 {
 133         pte_t old_pte = *ptep;
 134         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
 135 }
 136 #endif
 137
 138 #ifndef __HAVE_ARCH_PTE_SAME
 139 #define pte_same(A,B)   (pte_val(A) == pte_val(B))
 140 #endif
 141
 142 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
 143 #define page_test_and_clear_dirty(page) (0)
 144 #define pte_maybe_dirty(pte)            pte_dirty(pte)
 145 #else
 146 #define pte_maybe_dirty(pte)            (1)
 147 #endif
 148
 149 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 150 #define page_test_and_clear_young(page) (0)
 151 #endif
 152
 153 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
 154 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
 155 #endif
 156
 157 #ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
 158 #define lazy_mmu_prot_update(pte)       do { } while (0)
 159 #endif
 160
 161 #ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE
 162 #define move_pte(pte, prot, old_addr, new_addr) (pte)
 163 #else
 164 #define move_pte(pte, prot, old_addr, new_addr)                         \
 165 ({                                                                      \
 166         pte_t newpte = (pte);                                           \
 167         if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&              \
 168                         pte_page(pte) == ZERO_PAGE(old_addr))           \
 169                 newpte = mk_pte(ZERO_PAGE(new_addr), (prot));           \
 170         newpte;                                                         \
 171 })
 172 #endif
 173
 174 /*
 175  * When walking page tables, get the address of the next boundary,
 176  * or the end address of the range if that comes earlier.  Although no
 177  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
 178  */
 179
 180 #define pgd_addr_end(addr, end)                                         \
 181 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
 182         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 183 })
 184
 185 #ifndef pud_addr_end
 186 #define pud_addr_end(addr, end)                                         \
 187 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
 188         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 189 })
 190 #endif
 191
 192 #ifndef pmd_addr_end
 193 #define pmd_addr_end(addr, end)                                         \
 194 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
 195         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 196 })
 197 #endif
 198
 199 #ifndef __ASSEMBLY__
 200 /*
 201  * When walking page tables, we usually want to skip any p?d_none entries;
 202  * and any p?d_bad entries - reporting the error before resetting to none.
 203  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
 204  */
 205 void pgd_clear_bad(pgd_t *);
 206 void pud_clear_bad(pud_t *);
 207 void pmd_clear_bad(pmd_t *);
 208
 209 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
 210 {
 211         if (pgd_none(*pgd))
 212                 return 1;
 213         if (unlikely(pgd_bad(*pgd))) {
 214                 pgd_clear_bad(pgd);
 215                 return 1;
 216         }
 217         return 0;
 218 }
 219
 220 static inline int pud_none_or_clear_bad(pud_t *pud)
 221 {
 222         if (pud_none(*pud))
 223                 return 1;
 224         if (unlikely(pud_bad(*pud))) {
 225                 pud_clear_bad(pud);
 226                 return 1;
 227         }
 228         return 0;
 229 }
 230
 231 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
 232 {
 233         if (pmd_none(*pmd))
 234                 return 1;
 235         if (unlikely(pmd_bad(*pmd))) {
 236                 pmd_clear_bad(pmd);
 237                 return 1;
 238         }
 239         return 0;
 240 }
 241 #endif /* !__ASSEMBLY__ */
 242
 243 #endif /* _ASM_GENERIC_PGTABLE_H */