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_ESTABLISH_NEW
  46 /*
  47  * Establish a mapping where none previously existed
  48  */
  49 #define ptep_establish_new(__vma, __address, __ptep, __entry)           \
  50 do {                                                                    \
  51         set_pte(__ptep, __entry);                                       \
  52 } while (0)
  53 #define set_pte_at_new(__a, __b, __c, __d) set_pte_at(__a, __b, __c, __d)
  54 #endif
  55
  56 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  57 #define ptep_test_and_clear_young(__vma, __address, __ptep)             \
  58 ({                                                                      \
  59         pte_t __pte = *(__ptep);                                        \
  60         int r = 1;                                                      \
  61         if (!pte_young(__pte))                                          \
  62                 r = 0;                                                  \
  63         else                                                            \
  64                 set_pte_at((__vma)->vm_mm, (__address),                 \
  65                            (__ptep), pte_mkold(__pte));                 \
  66         r;                                                              \
  67 })
  68 #endif
  69
  70 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  71 #define ptep_clear_flush_young(__vma, __address, __ptep)                \
  72 ({                                                                      \
  73         int __young;                                                    \
  74         __young = ptep_test_and_clear_young(__vma, __address, __ptep);  \
  75         if (__young)                                                    \
  76                 flush_tlb_page(__vma, __address);                       \
  77         __young;                                                        \
  78 })
  79 #endif
  80
  81 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
  82 #define ptep_test_and_clear_dirty(__vma, __address, __ptep)             \
  83 ({                                                                      \
  84         pte_t __pte = *__ptep;                                          \
  85         int r = 1;                                                      \
  86         if (!pte_dirty(__pte))                                          \
  87                 r = 0;                                                  \
  88         else                                                            \
  89                 set_pte_at((__vma)->vm_mm, (__address), (__ptep),       \
  90                            pte_mkclean(__pte));                         \
  91         r;                                                              \
  92 })
  93 #endif
  94
  95 #ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
  96 #define ptep_clear_flush_dirty(__vma, __address, __ptep)                \
  97 ({                                                                      \
  98         int __dirty;                                                    \
  99         __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep);  \
 100         if (__dirty)                                                    \
 101                 flush_tlb_page(__vma, __address);                       \
 102         __dirty;                                                        \
 103 })
 104 #endif
 105
 106 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
 107 #define ptep_get_and_clear(__mm, __address, __ptep)                     \
 108 ({                                                                      \
 109         pte_t __pte = *(__ptep);                                        \
 110         pte_clear((__mm), (__address), (__ptep));                       \
 111         __pte;                                                          \
 112 })
 113 #endif
 114
 115 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 116 #define ptep_clear_flush(__vma, __address, __ptep)                      \
 117 ({                                                                      \
 118         pte_t __pte;                                                    \
 119         __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
 120         flush_tlb_page(__vma, __address);                               \
 121         __pte;                                                          \
 122 })
 123 #endif
 124
 125 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
 126 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 127 {
 128         pte_t old_pte = *ptep;
 129         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
 130 }
 131 #endif
 132
 133 #ifndef __HAVE_ARCH_PTE_SAME
 134 #define pte_same(A,B)   (pte_val(A) == pte_val(B))
 135 #endif
 136
 137 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
 138 #define page_test_and_clear_dirty(page) (0)
 139 #endif
 140
 141 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 142 #define page_test_and_clear_young(page) (0)
 143 #endif
 144
 145 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
 146 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
 147 #endif
 148
 149 #ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
 150 #define lazy_mmu_prot_update(pte)       do { } while (0)
 151 #endif
 152
 153 /*
 154  * When walking page tables, get the address of the next boundary,
 155  * or the end address of the range if that comes earlier.  Although no
 156  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
 157  */
 158
 159 #define pgd_addr_end(addr, end)                                         \
 160 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
 161         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 162 })
 163
 164 #ifndef pud_addr_end
 165 #define pud_addr_end(addr, end)                                         \
 166 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
 167         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 168 })
 169 #endif
 170
 171 #ifndef pmd_addr_end
 172 #define pmd_addr_end(addr, end)                                         \
 173 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
 174         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 175 })
 176 #endif
 177
 178 #ifndef __ASSEMBLY__
 179 /*
 180  * When walking page tables, we usually want to skip any p?d_none entries;
 181  * and any p?d_bad entries - reporting the error before resetting to none.
 182  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
 183  */
 184 void pgd_clear_bad(pgd_t *);
 185 void pud_clear_bad(pud_t *);
 186 void pmd_clear_bad(pmd_t *);
 187
 188 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
 189 {
 190         if (pgd_none(*pgd))
 191                 return 1;
 192         if (unlikely(pgd_bad(*pgd))) {
 193                 pgd_clear_bad(pgd);
 194                 return 1;
 195         }
 196         return 0;
 197 }
 198
 199 static inline int pud_none_or_clear_bad(pud_t *pud)
 200 {
 201         if (pud_none(*pud))
 202                 return 1;
 203         if (unlikely(pud_bad(*pud))) {
 204                 pud_clear_bad(pud);
 205                 return 1;
 206         }
 207         return 0;
 208 }
 209
 210 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
 211 {
 212         if (pmd_none(*pmd))
 213                 return 1;
 214         if (unlikely(pmd_bad(*pmd))) {
 215                 pmd_clear_bad(pmd);
 216                 return 1;
 217         }
 218         return 0;
 219 }
 220 #endif /* !__ASSEMBLY__ */
 221
 222 #endif /* _ASM_GENERIC_PGTABLE_H */