1 files changed, 17 insertions, 0 deletions

diff --git a/include/asm-powerpc/spinlock.h b/include/asm-powerpc/spinlock.h
index 895cb6d3a42a..c31e4382a775 100644
--- a/include/asm-powerpc/spinlock.h
+++ b/include/asm-powerpc/spinlock.h
@@ -36,6 +36,19 @@
 #define LOCK_TOKEN      1
 #endif
 
+#if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
+#define CLEAR_IO_SYNC   (get_paca()->io_sync = 0)
+#define SYNC_IO         do {                                            \
+                                if (unlikely(get_paca()->io_sync)) {    \
+                                        mb();                           \
+                                        get_paca()->io_sync = 0;        \
+                                }                                       \
+                        } while (0)
+#else
+#define CLEAR_IO_SYNC
+#define SYNC_IO
+#endif
+
 /*
  * This returns the old value in the lock, so we succeeded
  * in getting the lock if the return value is 0.
@@ -61,6 +74,7 @@ static __inline__ unsigned long __spin_trylock(raw_spinlock_t *lock)
 
 static int __inline__ __raw_spin_trylock(raw_spinlock_t *lock)
 {
+        CLEAR_IO_SYNC;
         return __spin_trylock(lock) == 0;
 }
 
@@ -91,6 +105,7 @@ extern void __rw_yield(raw_rwlock_t *lock);
 
 static void __inline__ __raw_spin_lock(raw_spinlock_t *lock)
 {
+        CLEAR_IO_SYNC;
         while (1) {
                 if (likely(__spin_trylock(lock) == 0))
                         break;
@@ -107,6 +122,7 @@ static void __inline__ __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long
 {
         unsigned long flags_dis;
 
+        CLEAR_IO_SYNC;
         while (1) {
                 if (likely(__spin_trylock(lock) == 0))
                         break;
@@ -124,6 +140,7 @@ static void __inline__ __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long
 
 static __inline__ void __raw_spin_unlock(raw_spinlock_t *lock)
 {
+        SYNC_IO;
         __asm__ __volatile__("# __raw_spin_unlock\n\t"
                                 LWSYNC_ON_SMP: : :"memory");
         lock->slock = 0;