1 files changed, 52 insertions, 9 deletions

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index ee99723b3a6..16b52f39798 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -44,11 +44,29 @@ static inline void atomic_set(atomic_t *v, int i)
         : "cc");
 }
 
+static inline void atomic_add(int i, atomic_t *v)
+{
+        unsigned long tmp;
+        int result;
+
+        __asm__ __volatile__("@ atomic_add\n"
+"1:     ldrex   %0, [%2]\n"
+"       add     %0, %0, %3\n"
+"       strex   %1, %0, [%2]\n"
+"       teq     %1, #0\n"
+"       bne     1b"
+        : "=&r" (result), "=&r" (tmp)
+        : "r" (&v->counter), "Ir" (i)
+        : "cc");
+}
+
 static inline int atomic_add_return(int i, atomic_t *v)
 {
         unsigned long tmp;
         int result;
 
+        smp_mb();
+
         __asm__ __volatile__("@ atomic_add_return\n"
 "1:     ldrex   %0, [%2]\n"
 "       add     %0, %0, %3\n"
@@ -59,14 +77,34 @@ static inline int atomic_add_return(int i, atomic_t *v)
         : "r" (&v->counter), "Ir" (i)
         : "cc");
 
+        smp_mb();
+
         return result;
 }
 
+static inline void atomic_sub(int i, atomic_t *v)
+{
+        unsigned long tmp;
+        int result;
+
+        __asm__ __volatile__("@ atomic_sub\n"
+"1:     ldrex   %0, [%2]\n"
+"       sub     %0, %0, %3\n"
+"       strex   %1, %0, [%2]\n"
+"       teq     %1, #0\n"
+"       bne     1b"
+        : "=&r" (result), "=&r" (tmp)
+        : "r" (&v->counter), "Ir" (i)
+        : "cc");
+}
+
 static inline int atomic_sub_return(int i, atomic_t *v)
 {
         unsigned long tmp;
         int result;
 
+        smp_mb();
+
         __asm__ __volatile__("@ atomic_sub_return\n"
 "1:     ldrex   %0, [%2]\n"
 "       sub     %0, %0, %3\n"
@@ -77,6 +115,8 @@ static inline int atomic_sub_return(int i, atomic_t *v)
         : "r" (&v->counter), "Ir" (i)
         : "cc");
 
+        smp_mb();
+
         return result;
 }
 
@@ -84,6 +124,8 @@ static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
 {
         unsigned long oldval, res;
 
+        smp_mb();
+
         do {
                 __asm__ __volatile__("@ atomic_cmpxchg\n"
                 "ldrex  %1, [%2]\n"
@@ -95,6 +137,8 @@ static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
                     : "cc");
         } while (res);
 
+        smp_mb();
+
         return oldval;
 }
 
@@ -135,6 +179,7 @@ static inline int atomic_add_return(int i, atomic_t *v)
 
         return val;
 }
+#define atomic_add(i, v)        (void) atomic_add_return(i, v)
 
 static inline int atomic_sub_return(int i, atomic_t *v)
 {
@@ -148,6 +193,7 @@ static inline int atomic_sub_return(int i, atomic_t *v)
 
         return val;
 }
+#define atomic_sub(i, v)        (void) atomic_sub_return(i, v)
 
 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 {
@@ -187,10 +233,8 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 }
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 
-#define atomic_add(i, v)        (void) atomic_add_return(i, v)
-#define atomic_inc(v)           (void) atomic_add_return(1, v)
-#define atomic_sub(i, v)        (void) atomic_sub_return(i, v)
-#define atomic_dec(v)           (void) atomic_sub_return(1, v)
+#define atomic_inc(v)           atomic_add(1, v)
+#define atomic_dec(v)           atomic_sub(1, v)
 
 #define atomic_inc_and_test(v)  (atomic_add_return(1, v) == 0)
 #define atomic_dec_and_test(v)  (atomic_sub_return(1, v) == 0)
@@ -200,11 +244,10 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
 
 #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
 
-/* Atomic operations are already serializing on ARM */
-#define smp_mb__before_atomic_dec()     barrier()
-#define smp_mb__after_atomic_dec()      barrier()
-#define smp_mb__before_atomic_inc()     barrier()
-#define smp_mb__after_atomic_inc()      barrier()
+#define smp_mb__before_atomic_dec()     smp_mb()
+#define smp_mb__after_atomic_dec()      smp_mb()
+#define smp_mb__before_atomic_inc()     smp_mb()
+#define smp_mb__after_atomic_inc()      smp_mb()
 
 #include <asm-generic/atomic.h>
 #endif