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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-19 03:44:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-19 03:44:24 +0300
commita200dcb34693084e56496960d855afdeaaf9578f (patch)
treebf65e4350460b7f98247278469f7600d1808c3fc /include/asm-generic
parentd05d82f7110b08fd36178a641b69a1f206e1142b (diff)
parent43e361f23c49dbddf74f56ddf6cdd85c5dbff6da (diff)
downloadlinux-a200dcb34693084e56496960d855afdeaaf9578f.tar.xz
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 'include/asm-generic')
-rw-r--r--include/asm-generic/barrier.h106
1 files changed, 97 insertions, 9 deletions
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 0f45f93ef692..1cceca146905 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -54,22 +54,38 @@
#define read_barrier_depends() do { } while (0)
#endif
+#ifndef __smp_mb
+#define __smp_mb() mb()
+#endif
+
+#ifndef __smp_rmb
+#define __smp_rmb() rmb()
+#endif
+
+#ifndef __smp_wmb
+#define __smp_wmb() wmb()
+#endif
+
+#ifndef __smp_read_barrier_depends
+#define __smp_read_barrier_depends() read_barrier_depends()
+#endif
+
#ifdef CONFIG_SMP
#ifndef smp_mb
-#define smp_mb() mb()
+#define smp_mb() __smp_mb()
#endif
#ifndef smp_rmb
-#define smp_rmb() rmb()
+#define smp_rmb() __smp_rmb()
#endif
#ifndef smp_wmb
-#define smp_wmb() wmb()
+#define smp_wmb() __smp_wmb()
#endif
#ifndef smp_read_barrier_depends
-#define smp_read_barrier_depends() read_barrier_depends()
+#define smp_read_barrier_depends() __smp_read_barrier_depends()
#endif
#else /* !CONFIG_SMP */
@@ -92,32 +108,104 @@
#endif /* CONFIG_SMP */
+#ifndef __smp_store_mb
+#define __smp_store_mb(var, value) do { WRITE_ONCE(var, value); __smp_mb(); } while (0)
+#endif
+
+#ifndef __smp_mb__before_atomic
+#define __smp_mb__before_atomic() __smp_mb()
+#endif
+
+#ifndef __smp_mb__after_atomic
+#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); \
+ compiletime_assert_atomic_type(*p); \
+ __smp_mb(); \
+ ___p1; \
+})
+#endif
+
+#ifdef CONFIG_SMP
+
+#ifndef smp_store_mb
+#define smp_store_mb(var, value) __smp_store_mb(var, value)
+#endif
+
+#ifndef smp_mb__before_atomic
+#define smp_mb__before_atomic() __smp_mb__before_atomic()
+#endif
+
+#ifndef smp_mb__after_atomic
+#define smp_mb__after_atomic() __smp_mb__after_atomic()
+#endif
+
+#ifndef smp_store_release
+#define smp_store_release(p, v) __smp_store_release(p, v)
+#endif
+
+#ifndef smp_load_acquire
+#define smp_load_acquire(p) __smp_load_acquire(p)
+#endif
+
+#else /* !CONFIG_SMP */
+
#ifndef smp_store_mb
-#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
+#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); barrier(); } while (0)
#endif
#ifndef smp_mb__before_atomic
-#define smp_mb__before_atomic() smp_mb()
+#define smp_mb__before_atomic() barrier()
#endif
#ifndef smp_mb__after_atomic
-#define smp_mb__after_atomic() smp_mb()
+#define smp_mb__after_atomic() barrier()
#endif
+#ifndef smp_store_release
#define smp_store_release(p, v) \
do { \
compiletime_assert_atomic_type(*p); \
- smp_mb(); \
+ barrier(); \
WRITE_ONCE(*p, v); \
} while (0)
+#endif
+#ifndef smp_load_acquire
#define smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
compiletime_assert_atomic_type(*p); \
- smp_mb(); \
+ barrier(); \
___p1; \
})
+#endif
+
+#endif
+
+/* Barriers for virtual machine guests when talking to an SMP host */
+#define virt_mb() __smp_mb()
+#define virt_rmb() __smp_rmb()
+#define virt_wmb() __smp_wmb()
+#define virt_read_barrier_depends() __smp_read_barrier_depends()
+#define virt_store_mb(var, value) __smp_store_mb(var, value)
+#define virt_mb__before_atomic() __smp_mb__before_atomic()
+#define virt_mb__after_atomic() __smp_mb__after_atomic()
+#define virt_store_release(p, v) __smp_store_release(p, v)
+#define virt_load_acquire(p) __smp_load_acquire(p)
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_GENERIC_BARRIER_H */