[SPARC64]: More fully work around Spitfire Errata 51.
It appears that a memory barrier soon after a mispredicted
branch, not just in the delay slot, can cause the hang
condition of this cpu errata.
So move them out-of-line, and explicitly put them into
a "branch always, predict taken" delay slot which should
fully kill this problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/asm-sparc64/system.h b/include/asm-sparc64/system.h
index ee4bdfc..5e94c05 100644
--- a/include/asm-sparc64/system.h
+++ b/include/asm-sparc64/system.h
@@ -28,6 +28,14 @@
#define ARCH_SUN4C_SUN4 0
#define ARCH_SUN4 0
+extern void mb(void);
+extern void rmb(void);
+extern void wmb(void);
+extern void membar_storeload(void);
+extern void membar_storeload_storestore(void);
+extern void membar_storeload_loadload(void);
+extern void membar_storestore_loadstore(void);
+
#endif
#define setipl(__new_ipl) \
@@ -78,16 +86,11 @@
#define nop() __asm__ __volatile__ ("nop")
-#define membar(type) __asm__ __volatile__ ("membar " type : : : "memory")
-#define mb() \
- membar("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
-#define rmb() membar("#LoadLoad")
-#define wmb() membar("#StoreStore")
#define read_barrier_depends() do { } while(0)
#define set_mb(__var, __value) \
- do { __var = __value; membar("#StoreLoad | #StoreStore"); } while(0)
+ do { __var = __value; membar_storeload_storestore(); } while(0)
#define set_wmb(__var, __value) \
- do { __var = __value; membar("#StoreStore"); } while(0)
+ do { __var = __value; wmb(); } while(0)
#ifdef CONFIG_SMP
#define smp_mb() mb()