tools/virtio: remove smp_read_barrier_depends()

This gets rid of the last references to smp_read_barrier_depends()
 which for the kernel side was removed in v5.9. The serialization
required for Alpha is done inside READ_ONCE() instead of having
users deal with it. Simply use a full barrier, the architecture
does not have rmb in the first place.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Message-Id: <20221128034347.990-3-dave@stgolabs.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
This commit is contained in:
Davidlohr Bueso 2022-11-27 19:43:47 -08:00 committed by Michael S. Tsirkin
parent 8aeac42d60
commit 81931012bd

View File

@ -140,12 +140,6 @@ static inline void busy_wait(void)
#define smp_wmb() smp_release()
#endif
#ifdef __alpha__
#define smp_read_barrier_depends() smp_acquire()
#else
#define smp_read_barrier_depends() do {} while(0)
#endif
static __always_inline
void __read_once_size(const volatile void *p, void *res, int size)
{
@ -175,13 +169,22 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
}
}
#ifdef __alpha__
#define READ_ONCE(x) \
({ \
union { typeof(x) __val; char __c[1]; } __u; \
__read_once_size(&(x), __u.__c, sizeof(x)); \
smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
smp_mb(); /* Enforce dependency ordering from x */ \
__u.__val; \
})
#else
#define READ_ONCE(x) \
({ \
union { typeof(x) __val; char __c[1]; } __u; \
__read_once_size(&(x), __u.__c, sizeof(x)); \
__u.__val; \
})
#endif
#define WRITE_ONCE(x, val) \
({ \