From: Marco Elver elver@google.com
[ Upstream commit 2505a51ac6f249956735e0a369e2404f96eebef0 ]
Thus far only smp_*() barriers had been defined by asm-generic/barrier.h based on __smp_*() barriers, because the !SMP case is usually generic.
With the introduction of instrumentation, it also makes sense to have asm-generic/barrier.h assist in the definition of instrumented versions of mb(), rmb(), wmb(), dma_rmb(), and dma_wmb().
Because there is no requirement to distinguish the !SMP case, the definition can be simpler: we can avoid also providing fallbacks for the __ prefixed cases, and only check if `defined(__<barrier>)`, to finally define the KCSAN-instrumented versions.
This also allows for the compiler to complain if an architecture accidentally defines both the normal and __ prefixed variant.
Signed-off-by: Marco Elver elver@google.com Signed-off-by: Paul E. McKenney paulmck@kernel.org Stable-dep-of: aa6956150f82 ("wifi: ath11k: fix dest ring-buffer corruption when ring is full") Signed-off-by: Sasha Levin sashal@kernel.org --- include/asm-generic/barrier.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 640f09479bdf..05aae2922485 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -20,6 +20,31 @@ #define nop() asm volatile ("nop") #endif
+/* + * Architectures that want generic instrumentation can define __ prefixed + * variants of all barriers. + */ + +#ifdef __mb +#define mb() do { kcsan_mb(); __mb(); } while (0) +#endif + +#ifdef __rmb +#define rmb() do { kcsan_rmb(); __rmb(); } while (0) +#endif + +#ifdef __wmb +#define wmb() do { kcsan_wmb(); __wmb(); } while (0) +#endif + +#ifdef __dma_rmb +#define dma_rmb() do { kcsan_rmb(); __dma_rmb(); } while (0) +#endif + +#ifdef __dma_wmb +#define dma_wmb() do { kcsan_wmb(); __dma_wmb(); } while (0) +#endif + /* * Force strict CPU ordering. And yes, this is required on UP too when we're * talking to devices.