net/mlx5: share Rx queue indirection table code

[dpdk.git] / drivers / net / virtio / virtqueue.h

diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 4f6956d..105a9c0 100644 (file)
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -505,8 +505,24 @@ void vq_ring_free_inorder(struct virtqueue *vq, uint16_t desc_idx,
 static inline void
 vq_update_avail_idx(struct virtqueue *vq)
 {
-       virtio_wmb(vq->hw->weak_barriers);
-       vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
+       if (vq->hw->weak_barriers) {
+       /* x86 prefers to using rte_smp_wmb over __atomic_store_n as
+        * it reports a slightly better perf, which comes from the
+        * saved branch by the compiler.
+        * The if and else branches are identical with the smp and
+        * cio barriers both defined as compiler barriers on x86.
+        */
+#ifdef RTE_ARCH_X86_64
+               rte_smp_wmb();
+               vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
+#else
+               __atomic_store_n(&vq->vq_split.ring.avail->idx,
+                                vq->vq_avail_idx, __ATOMIC_RELEASE);
+#endif
+       } else {
+               rte_cio_wmb();
+               vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
+       }
 }
 
 static inline void