ringtest: commonize implementation of poll_avail/poll_used
Provide new primitives used_empty/avail_empty and
build poll_avail/poll_used on top of it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/tools/virtio/ringtest/ring.c b/tools/virtio/ringtest/ring.c
index c25c8d2..747c5dd 100644
--- a/tools/virtio/ringtest/ring.c
+++ b/tools/virtio/ringtest/ring.c
@@ -163,12 +163,11 @@
return datap;
}
-void poll_used(void)
+bool used_empty()
{
unsigned head = (ring_size - 1) & guest.last_used_idx;
- while (ring[head].flags & DESC_HW)
- busy_wait();
+ return (ring[head].flags & DESC_HW);
}
void disable_call()
@@ -180,13 +179,11 @@
bool enable_call()
{
- unsigned head = (ring_size - 1) & guest.last_used_idx;
-
event->call_index = guest.last_used_idx;
/* Flush call index write */
/* Barrier D (for pairing) */
smp_mb();
- return ring[head].flags & DESC_HW;
+ return used_empty();
}
void kick_available(void)
@@ -213,20 +210,17 @@
bool enable_kick()
{
- unsigned head = (ring_size - 1) & host.used_idx;
-
event->kick_index = host.used_idx;
/* Barrier C (for pairing) */
smp_mb();
- return !(ring[head].flags & DESC_HW);
+ return avail_empty();
}
-void poll_avail(void)
+bool avail_empty()
{
unsigned head = (ring_size - 1) & host.used_idx;
- while (!(ring[head].flags & DESC_HW))
- busy_wait();
+ return !(ring[head].flags & DESC_HW);
}
bool use_buf(unsigned *lenp, void **bufp)