MIPS: New macro smp_mb__before_llsc.
Replace some instances of smp_llsc_mb() with a new macro
smp_mb__before_llsc(). It is used before ll/sc sequences that are
documented as needing write barrier semantics.
The default implementation of smp_mb__before_llsc() is just smp_llsc_mb(),
so there are no changes in semantics.
Also simplify definition of smp_mb(), smp_rmb(), and smp_wmb() to be just
barrier() in the non-SMP case.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/851/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h
index 83b5509..bb937cc 100644
--- a/arch/mips/include/asm/system.h
+++ b/arch/mips/include/asm/system.h
@@ -95,6 +95,8 @@
{
__u32 retval;
+ smp_mb__before_llsc();
+
if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long dummy;
@@ -147,6 +149,8 @@
{
__u64 retval;
+ smp_mb__before_llsc();
+
if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long dummy;