Alpha overrides __READ_ONCE() directly, so there's no need to use smp_read_barrier_depends() in the core code. This also means that __READ_ONCE() can be relied upon to provide dependency ordering.
Acked-by: Paul E. McKenney <paul...@kernel.org> Signed-off-by: Will Deacon <w...@kernel.org> --- include/asm-generic/rwonce.h | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/include/asm-generic/rwonce.h b/include/asm-generic/rwonce.h index f9dfa88fc04d..cc810f1f18ca 100644 --- a/include/asm-generic/rwonce.h +++ b/include/asm-generic/rwonce.h @@ -30,24 +30,16 @@ /* * Use __READ_ONCE() instead of READ_ONCE() if you do not require any - * atomicity or dependency ordering guarantees. Note that this may result - * in tears! + * atomicity. Note that this may result in tears! */ #ifndef __READ_ONCE #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x)) #endif -#define __READ_ONCE_SCALAR(x) \ -({ \ - __unqual_scalar_typeof(x) __x = __READ_ONCE(x); \ - smp_read_barrier_depends(); \ - (typeof(x))__x; \ -}) - #define READ_ONCE(x) \ ({ \ compiletime_assert_rwonce_type(x); \ - __READ_ONCE_SCALAR(x); \ + __READ_ONCE(x); \ }) #define __WRITE_ONCE(x, val) \ @@ -74,12 +66,9 @@ unsigned long __read_once_word_nocheck(const void *addr) */ #define READ_ONCE_NOCHECK(x) \ ({ \ - unsigned long __x; \ - compiletime_assert(sizeof(x) == sizeof(__x), \ + compiletime_assert(sizeof(x) == sizeof(unsigned long), \ "Unsupported access size for READ_ONCE_NOCHECK()."); \ - __x = __read_once_word_nocheck(&(x)); \ - smp_read_barrier_depends(); \ - (typeof(x))__x; \ + (typeof(x))__read_once_word_nocheck(&(x)); \ }) static __no_kasan_or_inline -- 2.27.0.383.g050319c2ae-goog _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization