1 files changed, 30 insertions, 0 deletions

diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
index cdaa58c9b39e..8f50fb3f04e1 100644
--- a/arch/x86/include/asm/pgtable-3level.h
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -121,6 +121,12 @@ static inline void native_pmd_clear(pmd_t *pmd)
         *(tmp + 1) = 0;
 }
 
+#ifndef CONFIG_SMP
+static inline void native_pud_clear(pud_t *pudp)
+{
+}
+#endif
+
 static inline void pud_clear(pud_t *pudp)
 {
         set_pud(pudp, __pud(0));
@@ -176,6 +182,30 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp)
 #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
 #endif
 
+#ifdef CONFIG_SMP
+union split_pud {
+        struct {
+                u32 pud_low;
+                u32 pud_high;
+        };
+        pud_t pud;
+};
+
+static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
+{
+        union split_pud res, *orig = (union split_pud *)pudp;
+
+        /* xchg acts as a barrier before setting of the high bits */
+        res.pud_low = xchg(&orig->pud_low, 0);
+        res.pud_high = orig->pud_high;
+        orig->pud_high = 0;
+
+        return res.pud;
+}
+#else
+#define native_pudp_get_and_clear(xp) native_local_pudp_get_and_clear(xp)
+#endif
+
 /* Encode and de-code a swap entry */
 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
 #define __swp_type(x)                   (((x).val) & 0x1f)