From: Keir Fraser <keir@xen.org>
Date: Thu, 16 Dec 2010 19:36:35 +0000 (+0000)
Subject: x86: Define pte_{read,write}[_atomic] in terms of atomic_readN
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x86: Define pte_{read,write}[_atomic] in terms of atomic_readN

Signed-off-by: Keir Fraser <keir@xen.org>
---

diff --git a/xen/include/asm-x86/x86_32/page.h b/xen/include/asm-x86/x86_32/page.h
index 58419046b8..5c6a183dc6 100644
--- a/xen/include/asm-x86/x86_32/page.h
+++ b/xen/include/asm-x86/x86_32/page.h
@@ -84,19 +84,15 @@ extern unsigned int PAGE_HYPERVISOR_NOCACHE;
 
 #endif
 
-#define pte_read_atomic(ptep) cmpxchg(ptep, 0, 0)
-#define pte_write_atomic(ptep, pte) do {                      \
-    intpte_t __pte = *(ptep), __npte;                         \
-    while ( (__npte = cmpxchg(ptep, __pte, (pte))) != __pte ) \
-        __pte = __npte;                                       \
-} while ( 0 )
+#define pte_read_atomic(ptep)       atomic_read64(ptep)
+#define pte_write_atomic(ptep, pte) atomic_write64(ptep, pte)
 #define pte_write(ptep, pte) do {                             \
     u32 *__ptep_words = (u32 *)(ptep);                        \
-    __ptep_words[0] = 0;                                      \
+    atomic_write32(&__ptep_words[0], 0);                      \
     wmb();                                                    \
-    __ptep_words[1] = (pte) >> 32;                            \
+    atomic_write32(&__ptep_words[1], (pte) >> 32);            \
     wmb();                                                    \
-    __ptep_words[0] = (pte) >>  0;                            \
+    atomic_write32(&__ptep_words[0], (pte) >>  0);            \
 } while ( 0 )
 
 /* root table */
diff --git a/xen/include/asm-x86/x86_64/page.h b/xen/include/asm-x86/x86_64/page.h
index 2e61709e29..8e58c9b9eb 100644
--- a/xen/include/asm-x86/x86_64/page.h
+++ b/xen/include/asm-x86/x86_64/page.h
@@ -113,9 +113,9 @@ typedef l4_pgentry_t root_pgentry_t;
 
 #endif /* !__ASSEMBLY__ */
 
-#define pte_read_atomic(ptep)       (*(ptep))
-#define pte_write_atomic(ptep, pte) (*(ptep) = (pte))
-#define pte_write(ptep, pte)        (*(ptep) = (pte))
+#define pte_read_atomic(ptep)       atomic_read64(ptep)
+#define pte_write_atomic(ptep, pte) atomic_write64(ptep, pte)
+#define pte_write(ptep, pte)        atomic_write64(ptep, pte)
 
 /* Given a virtual address, get an entry offset into a linear page table. */
 #define l1_linear_offset(_a) (((_a) & VADDR_MASK) >> L1_PAGETABLE_SHIFT)