[PATCH 02/34] asm-generic: guard smp_store_release/load_acquire

Michael S. Tsirkin
2015-12-30T13:24:27Z

Allow architectures to override smp_store_release
and smp_load_acquire by guarding the defines
in asm-generic/barrier.h with ifndef directives.

This is in preparation to reusing asm-generic/barrier.h
on architectures which have their own definition
of these macros.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/asm-generic/barrier.h | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index b42afad..538f8d1 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -104,13 +104,16 @@
#define smp_mb__after_atomic() smp_mb()
#endif

+#ifndef smp_store_release
#define smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
smp_mb(); \
WRITE_ONCE(*p, v); \
} while (0)
+#endif

+#ifndef smp_load_acquire
#define smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
@@ -118,6 +121,7 @@ do { \
smp_mb(); \
___p1; \
})
+#endif

#endif /* !__ASSEMBLY__ */
#endif /* __ASM_GENERIC_BARRIER_H */
--
MST