Commit 81931012 authored by Davidlohr Bueso's avatar Davidlohr Bueso Committed by Michael S. Tsirkin
Browse files

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: default avatarDavidlohr Bueso <dave@stgolabs.net>
Message-Id: <20221128034347.990-3-dave@stgolabs.net>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
parent 8aeac42d

tools/virtio/ringtest/main.h

+10 −7
Original line number Diff line number Diff line
@@ -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) \

({							\