1 files changed, 79 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
new file mode 100644
index 000000000000..81762081dcd8
--- /dev/null
+++ b/arch/x86/include/asm/pgtable-2level.h
@@ -0,0 +1,79 @@
+#ifndef ASM_X86__PGTABLE_2LEVEL_H
+#define ASM_X86__PGTABLE_2LEVEL_H
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/*
+ * Certain architectures need to do special things when PTEs
+ * within a page table are directly modified.  Thus, the following
+ * hook is made available.
+ */
+static inline void native_set_pte(pte_t *ptep , pte_t pte)
+{
+        *ptep = pte;
+}
+
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+        *pmdp = pmd;
+}
+
+static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
+{
+        native_set_pte(ptep, pte);
+}
+
+static inline void native_set_pte_present(struct mm_struct *mm,
+                                          unsigned long addr,
+                                          pte_t *ptep, pte_t pte)
+{
+        native_set_pte(ptep, pte);
+}
+
+static inline void native_pmd_clear(pmd_t *pmdp)
+{
+        native_set_pmd(pmdp, __pmd(0));
+}
+
+static inline void native_pte_clear(struct mm_struct *mm,
+                                    unsigned long addr, pte_t *xp)
+{
+        *xp = native_make_pte(0);
+}
+
+#ifdef CONFIG_SMP
+static inline pte_t native_ptep_get_and_clear(pte_t *xp)
+{
+        return __pte(xchg(&xp->pte_low, 0));
+}
+#else
+#define native_ptep_get_and_clear(xp) native_local_ptep_get_and_clear(xp)
+#endif
+
+#define pte_none(x)             (!(x).pte_low)
+
+/*
+ * Bits 0, 6 and 7 are taken, split up the 29 bits of offset
+ * into this range:
+ */
+#define PTE_FILE_MAX_BITS       29
+
+#define pte_to_pgoff(pte)                                               \
+        ((((pte).pte_low >> 1) & 0x1f) + (((pte).pte_low >> 8) << 5))
+
+#define pgoff_to_pte(off)                                               \
+        ((pte_t) { .pte_low = (((off) & 0x1f) << 1) +                   \
+                        (((off) >> 5) << 8) + _PAGE_FILE })
+
+/* Encode and de-code a swap entry */
+#define __swp_type(x)                   (((x).val >> 1) & 0x1f)
+#define __swp_offset(x)                 ((x).val >> 8)
+#define __swp_entry(type, offset)                               \
+        ((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
+#define __pte_to_swp_entry(pte)         ((swp_entry_t) { (pte).pte_low })
+#define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
+
+#endif /* ASM_X86__PGTABLE_2LEVEL_H */