1 files changed, 213 insertions, 0 deletions

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
new file mode 100644
index 000000000000..a3b28710d56c
--- /dev/null
+++ b/include/asm-generic/pgtable.h
@@ -0,0 +1,213 @@
+#ifndef _ASM_GENERIC_PGTABLE_H
+#define _ASM_GENERIC_PGTABLE_H
+
+#ifndef __HAVE_ARCH_PTEP_ESTABLISH
+/*
+ * Establish a new mapping:
+ *  - flush the old one
+ *  - update the page tables
+ *  - inform the TLB about the new one
+ *
+ * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock.
+ *
+ * Note: the old pte is known to not be writable, so we don't need to
+ * worry about dirty bits etc getting lost.
+ */
+#ifndef __HAVE_ARCH_SET_PTE_ATOMIC
+#define ptep_establish(__vma, __address, __ptep, __entry)               \
+do {                                                                    \
+        set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);       \
+        flush_tlb_page(__vma, __address);                               \
+} while (0)
+#else /* __HAVE_ARCH_SET_PTE_ATOMIC */
+#define ptep_establish(__vma, __address, __ptep, __entry)               \
+do {                                                                    \
+        set_pte_atomic(__ptep, __entry);                                \
+        flush_tlb_page(__vma, __address);                               \
+} while (0)
+#endif /* __HAVE_ARCH_SET_PTE_ATOMIC */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+/*
+ * Largely same as above, but only sets the access flags (dirty,
+ * accessed, and writable). Furthermore, we know it always gets set
+ * to a "more permissive" setting, which allows most architectures
+ * to optimize this.
+ */
+#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
+do {                                                                      \
+        set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);         \
+        flush_tlb_page(__vma, __address);                                 \
+} while (0)
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define ptep_test_and_clear_young(__vma, __address, __ptep)             \
+({                                                                      \
+        pte_t __pte = *(__ptep);                                        \
+        int r = 1;                                                      \
+        if (!pte_young(__pte))                                          \
+                r = 0;                                                  \
+        else                                                            \
+                set_pte_at((__vma)->vm_mm, (__address),                 \
+                           (__ptep), pte_mkold(__pte));                 \
+        r;                                                              \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+#define ptep_clear_flush_young(__vma, __address, __ptep)                \
+({                                                                      \
+        int __young;                                                    \
+        __young = ptep_test_and_clear_young(__vma, __address, __ptep);  \
+        if (__young)                                                    \
+                flush_tlb_page(__vma, __address);                       \
+        __young;                                                        \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
+#define ptep_test_and_clear_dirty(__vma, __address, __ptep)             \
+({                                                                      \
+        pte_t __pte = *__ptep;                                          \
+        int r = 1;                                                      \
+        if (!pte_dirty(__pte))                                          \
+                r = 0;                                                  \
+        else                                                            \
+                set_pte_at((__vma)->vm_mm, (__address), (__ptep),       \
+                           pte_mkclean(__pte));                         \
+        r;                                                              \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
+#define ptep_clear_flush_dirty(__vma, __address, __ptep)                \
+({                                                                      \
+        int __dirty;                                                    \
+        __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep);  \
+        if (__dirty)                                                    \
+                flush_tlb_page(__vma, __address);                       \
+        __dirty;                                                        \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
+#define ptep_get_and_clear(__mm, __address, __ptep)                     \
+({                                                                      \
+        pte_t __pte = *(__ptep);                                        \
+        pte_clear((__mm), (__address), (__ptep));                       \
+        __pte;                                                          \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
+#define ptep_clear_flush(__vma, __address, __ptep)                      \
+({                                                                      \
+        pte_t __pte;                                                    \
+        __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
+        flush_tlb_page(__vma, __address);                               \
+        __pte;                                                          \
+})
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
+{
+        pte_t old_pte = *ptep;
+        set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTE_SAME
+#define pte_same(A,B)   (pte_val(A) == pte_val(B))
+#endif
+
+#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
+#define page_test_and_clear_dirty(page) (0)
+#endif
+
+#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
+#define page_test_and_clear_young(page) (0)
+#endif
+
+#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
+#define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
+#endif
+
+#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
+#define lazy_mmu_prot_update(pte)       do { } while (0)
+#endif
+
+/*
+ * When walking page tables, get the address of the next boundary, or
+ * the end address of the range if that comes earlier.  Although end might
+ * wrap to 0 only in clear_page_range, __boundary may wrap to 0 throughout.
+ */
+
+#ifndef pgd_addr_end
+#define pgd_addr_end(addr, end)                                         \
+({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
+        (__boundary - 1 < (end) - 1)? __boundary: (end);                \
+})
+#endif
+
+#ifndef pud_addr_end
+#define pud_addr_end(addr, end)                                         \
+({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
+        (__boundary - 1 < (end) - 1)? __boundary: (end);                \
+})
+#endif
+
+#ifndef pmd_addr_end
+#define pmd_addr_end(addr, end)                                         \
+({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
+        (__boundary - 1 < (end) - 1)? __boundary: (end);                \
+})
+#endif
+
+#ifndef __ASSEMBLY__
+/*
+ * When walking page tables, we usually want to skip any p?d_none entries;
+ * and any p?d_bad entries - reporting the error before resetting to none.
+ * Do the tests inline, but report and clear the bad entry in mm/memory.c.
+ */
+void pgd_clear_bad(pgd_t *);
+void pud_clear_bad(pud_t *);
+void pmd_clear_bad(pmd_t *);
+
+static inline int pgd_none_or_clear_bad(pgd_t *pgd)
+{
+        if (pgd_none(*pgd))
+                return 1;
+        if (unlikely(pgd_bad(*pgd))) {
+                pgd_clear_bad(pgd);
+                return 1;
+        }
+        return 0;
+}
+
+static inline int pud_none_or_clear_bad(pud_t *pud)
+{
+        if (pud_none(*pud))
+                return 1;
+        if (unlikely(pud_bad(*pud))) {
+                pud_clear_bad(pud);
+                return 1;
+        }
+        return 0;
+}
+
+static inline int pmd_none_or_clear_bad(pmd_t *pmd)
+{
+        if (pmd_none(*pmd))
+                return 1;
+        if (unlikely(pmd_bad(*pmd))) {
+                pmd_clear_bad(pmd);
+                return 1;
+        }
+        return 0;
+}
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_GENERIC_PGTABLE_H */