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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-18 16:44:24 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-18 16:44:24 -0800
commita200dcb34693084e56496960d855afdeaaf9578f (patch)
treebf65e4350460b7f98247278469f7600d1808c3fc /arch/x86
parentd05d82f7110b08fd36178a641b69a1f206e1142b (diff)
parent43e361f23c49dbddf74f56ddf6cdd85c5dbff6da (diff)
downloadlinux-a200dcb34693084e56496960d855afdeaaf9578f.tar.bz2
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio barrier rework+fixes from Michael Tsirkin: "This adds a new kind of barrier, and reworks virtio and xen to use it. Plus some fixes here and there" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (44 commits) checkpatch: add virt barriers checkpatch: check for __smp outside barrier.h checkpatch.pl: add missing memory barriers virtio: make find_vqs() checkpatch.pl-friendly virtio_balloon: fix race between migration and ballooning virtio_balloon: fix race by fill and leak s390: more efficient smp barriers s390: use generic memory barriers xen/events: use virt_xxx barriers xen/io: use virt_xxx barriers xenbus: use virt_xxx barriers virtio_ring: use virt_store_mb sh: move xchg_cmpxchg to a header by itself sh: support 1 and 2 byte xchg virtio_ring: update weak barriers to use virt_xxx Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" asm-generic: implement virt_xxx memory barriers x86: define __smp_xxx xtensa: define __smp_xxx tile: define __smp_xxx ...
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/barrier.h36
-rw-r--r--arch/x86/um/asm/barrier.h9
2 files changed, 15 insertions, 30 deletions
diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 0681d2532527..a584e1c50918 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -31,20 +31,10 @@
#endif
#define dma_wmb() barrier()
-#ifdef CONFIG_SMP
-#define smp_mb() mb()
-#define smp_rmb() dma_rmb()
-#define smp_wmb() barrier()
-#define smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
-#else /* !SMP */
-#define smp_mb() barrier()
-#define smp_rmb() barrier()
-#define smp_wmb() barrier()
-#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
-#endif /* SMP */
-
-#define read_barrier_depends() do { } while (0)
-#define smp_read_barrier_depends() do { } while (0)
+#define __smp_mb() mb()
+#define __smp_rmb() dma_rmb()
+#define __smp_wmb() barrier()
+#define __smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
#if defined(CONFIG_X86_PPRO_FENCE)
@@ -53,31 +43,31 @@
* model and we should fall back to full barriers.
*/
-#define smp_store_release(p, v) \
+#define __smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
- smp_mb(); \
+ __smp_mb(); \
WRITE_ONCE(*p, v); \
} while (0)
-#define smp_load_acquire(p) \
+#define __smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
- smp_mb(); \
+ __smp_mb(); \
___p1; \
})
#else /* regular x86 TSO memory ordering */
-#define smp_store_release(p, v) \
+#define __smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
barrier(); \
WRITE_ONCE(*p, v); \
} while (0)
-#define smp_load_acquire(p) \
+#define __smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
@@ -88,7 +78,9 @@ do { \
#endif
/* Atomic operations are already serializing on x86 */
-#define smp_mb__before_atomic() barrier()
-#define smp_mb__after_atomic() barrier()
+#define __smp_mb__before_atomic() barrier()
+#define __smp_mb__after_atomic() barrier()
+
+#include <asm-generic/barrier.h>
#endif /* _ASM_X86_BARRIER_H */
diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h
index 755481f14d90..174781a404ff 100644
--- a/arch/x86/um/asm/barrier.h
+++ b/arch/x86/um/asm/barrier.h
@@ -36,13 +36,6 @@
#endif /* CONFIG_X86_PPRO_FENCE */
#define dma_wmb() barrier()
-#define smp_mb() barrier()
-#define smp_rmb() barrier()
-#define smp_wmb() barrier()
-
-#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
-
-#define read_barrier_depends() do { } while (0)
-#define smp_read_barrier_depends() do { } while (0)
+#include <asm-generic/barrier.h>
#endif