1 files changed, 79 insertions, 43 deletions

diff --git a/include/asm-x86/cmpxchg_32.h b/include/asm-x86/cmpxchg_32.h
index f86ede28f6dc..cea1dae288a7 100644
--- a/include/asm-x86/cmpxchg_32.h
+++ b/include/asm-x86/cmpxchg_32.h
@@ -105,15 +105,24 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 
 #ifdef CONFIG_X86_CMPXCHG
 #define __HAVE_ARCH_CMPXCHG 1
-#define cmpxchg(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
-                                        (unsigned long)(n),sizeof(*(ptr))))
-#define sync_cmpxchg(ptr,o,n)\
-        ((__typeof__(*(ptr)))__sync_cmpxchg((ptr),(unsigned long)(o),\
-                                        (unsigned long)(n),sizeof(*(ptr))))
-#define cmpxchg_local(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg_local((ptr),(unsigned long)(o),\
-                                        (unsigned long)(n),sizeof(*(ptr))))
+#define cmpxchg(ptr, o, n)                                                   \
+        ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),            \
+                                        (unsigned long)(n), sizeof(*(ptr))))
+#define sync_cmpxchg(ptr, o, n)                                              \
+        ((__typeof__(*(ptr)))__sync_cmpxchg((ptr), (unsigned long)(o),       \
+                                        (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg_local(ptr, o, n)                                             \
+        ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o),      \
+                                        (unsigned long)(n), sizeof(*(ptr))))
+#endif
+
+#ifdef CONFIG_X86_CMPXCHG64
+#define cmpxchg64(ptr, o, n)                                                  \
+        ((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o),      \
+                                        (unsigned long long)(n)))
+#define cmpxchg64_local(ptr, o, n)                                            \
+        ((__typeof__(*(ptr)))__cmpxchg64_local((ptr), (unsigned long long)(o),\
+                                        (unsigned long long)(n)))
 #endif
 
 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
@@ -203,6 +212,34 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
         return old;
 }
 
+static inline unsigned long long __cmpxchg64(volatile void *ptr,
+                        unsigned long long old, unsigned long long new)
+{
+        unsigned long long prev;
+        __asm__ __volatile__(LOCK_PREFIX "cmpxchg8b %3"
+                             : "=A"(prev)
+                             : "b"((unsigned long)new),
+                               "c"((unsigned long)(new >> 32)),
+                               "m"(*__xg(ptr)),
+                               "0"(old)
+                             : "memory");
+        return prev;
+}
+
+static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
+                        unsigned long long old, unsigned long long new)
+{
+        unsigned long long prev;
+        __asm__ __volatile__("cmpxchg8b %3"
+                             : "=A"(prev)
+                             : "b"((unsigned long)new),
+                               "c"((unsigned long)(new >> 32)),
+                               "m"(*__xg(ptr)),
+                               "0"(old)
+                             : "memory");
+        return prev;
+}
+
 #ifndef CONFIG_X86_CMPXCHG
 /*
  * Building a kernel capable running on 80386. It may be necessary to
@@ -228,7 +265,7 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
         return old;
 }
 
-#define cmpxchg(ptr,o,n)                                                \
+#define cmpxchg(ptr, o, n)                                              \
 ({                                                                      \
         __typeof__(*(ptr)) __ret;                                       \
         if (likely(boot_cpu_data.x86 > 3))                              \
@@ -239,7 +276,7 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
                                         (unsigned long)(n), sizeof(*(ptr))); \
         __ret;                                                          \
 })
-#define cmpxchg_local(ptr,o,n)                                          \
+#define cmpxchg_local(ptr, o, n)                                        \
 ({                                                                      \
         __typeof__(*(ptr)) __ret;                                       \
         if (likely(boot_cpu_data.x86 > 3))                              \
@@ -252,38 +289,37 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
 })
 #endif
 
-static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long long old,
-                                      unsigned long long new)
-{
-        unsigned long long prev;
-        __asm__ __volatile__(LOCK_PREFIX "cmpxchg8b %3"
-                             : "=A"(prev)
-                             : "b"((unsigned long)new),
-                               "c"((unsigned long)(new >> 32)),
-                               "m"(*__xg(ptr)),
-                               "0"(old)
-                             : "memory");
-        return prev;
-}
+#ifndef CONFIG_X86_CMPXCHG64
+/*
+ * Building a kernel capable running on 80386 and 80486. It may be necessary
+ * to simulate the cmpxchg8b on the 80386 and 80486 CPU.
+ */
 
-static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
-                        unsigned long long old, unsigned long long new)
-{
-        unsigned long long prev;
-        __asm__ __volatile__("cmpxchg8b %3"
-                             : "=A"(prev)
-                             : "b"((unsigned long)new),
-                               "c"((unsigned long)(new >> 32)),
-                               "m"(*__xg(ptr)),
-                               "0"(old)
-                             : "memory");
-        return prev;
-}
+extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64);
+
+#define cmpxchg64(ptr, o, n)                                            \
+({                                                                      \
+        __typeof__(*(ptr)) __ret;                                       \
+        if (likely(boot_cpu_data.x86 > 4))                              \
+                __ret = __cmpxchg64((ptr), (unsigned long long)(o),     \
+                                (unsigned long long)(n));               \
+        else                                                            \
+                __ret = cmpxchg_486_u64((ptr), (unsigned long long)(o), \
+                                (unsigned long long)(n));               \
+        __ret;                                                          \
+})
+#define cmpxchg64_local(ptr, o, n)                                      \
+({                                                                      \
+        __typeof__(*(ptr)) __ret;                                       \
+        if (likely(boot_cpu_data.x86 > 4))                              \
+                __ret = __cmpxchg64_local((ptr), (unsigned long long)(o), \
+                                (unsigned long long)(n));               \
+        else                                                            \
+                __ret = cmpxchg_486_u64((ptr), (unsigned long long)(o), \
+                                (unsigned long long)(n));               \
+        __ret;                                                          \
+})
+
+#endif
 
-#define cmpxchg64(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg64((ptr),(unsigned long long)(o),\
-                                        (unsigned long long)(n)))
-#define cmpxchg64_local(ptr,o,n)\
-        ((__typeof__(*(ptr)))__cmpxchg64_local((ptr),(unsigned long long)(o),\
-                                        (unsigned long long)(n)))
 #endif