net/virtio: optimize flags update for packed ring

[dpdk.git] / drivers / net / virtio / virtio_rxtx.c

diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 771d3c3..3c354ba 100644 (file)
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -431,7 +431,7 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq,
                                     struct rte_mbuf **cookie, uint16_t num)
 {
        struct vring_packed_desc *start_dp = vq->ring_packed.desc_packed;
-       uint16_t flags = VRING_DESC_F_WRITE | vq->avail_used_flags;
+       uint16_t flags = vq->cached_flags;
        struct virtio_hw *hw = vq->hw;
        struct vq_desc_extra *dxp;
        uint16_t idx;
@@ -460,11 +460,9 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq,
                start_dp[idx].flags = flags;
                if (++vq->vq_avail_idx >= vq->vq_nentries) {
                        vq->vq_avail_idx -= vq->vq_nentries;
-                       vq->avail_wrap_counter ^= 1;
-                       vq->avail_used_flags =
-                               VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
-                               VRING_DESC_F_USED(!vq->avail_wrap_counter);
-                       flags = VRING_DESC_F_WRITE | vq->avail_used_flags;
+                       vq->cached_flags ^=
+                               VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
+                       flags = vq->cached_flags;
                }
        }
        vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - num);
@@ -643,7 +641,7 @@ virtqueue_enqueue_xmit_packed_fast(struct virtnet_tx *txvq,
        dxp->ndescs = 1;
        dxp->cookie = cookie;
 
-       flags = vq->avail_used_flags;
+       flags = vq->cached_flags;
 
        /* prepend cannot fail, checked by caller */
        hdr = (struct virtio_net_hdr *)
@@ -662,8 +660,7 @@ virtqueue_enqueue_xmit_packed_fast(struct virtnet_tx *txvq,
 
        if (++vq->vq_avail_idx >= vq->vq_nentries) {
                vq->vq_avail_idx -= vq->vq_nentries;
-               vq->avail_wrap_counter ^= 1;
-               vq->avail_used_flags ^=
+               vq->cached_flags ^=
                        VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
        }
 
@@ -705,7 +702,7 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 
        head_dp = &vq->ring_packed.desc_packed[idx];
        head_flags = cookie->next ? VRING_DESC_F_NEXT : 0;
-       head_flags |= vq->avail_used_flags;
+       head_flags |= vq->cached_flags;
 
        if (can_push) {
                /* prepend cannot fail, checked by caller */
@@ -730,10 +727,8 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
                idx++;
                if (idx >= vq->vq_nentries) {
                        idx -= vq->vq_nentries;
-                       vq->avail_wrap_counter ^= 1;
-                       vq->avail_used_flags =
-                               VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
-                               VRING_DESC_F_USED(!vq->avail_wrap_counter);
+                       vq->cached_flags ^=
+                               VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
                }
        }
 
@@ -746,17 +741,15 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
                start_dp[idx].len  = cookie->data_len;
                if (likely(idx != head_idx)) {
                        flags = cookie->next ? VRING_DESC_F_NEXT : 0;
-                       flags |= vq->avail_used_flags;
+                       flags |= vq->cached_flags;
                        start_dp[idx].flags = flags;
                }
                prev = idx;
                idx++;
                if (idx >= vq->vq_nentries) {
                        idx -= vq->vq_nentries;
-                       vq->avail_wrap_counter ^= 1;
-                       vq->avail_used_flags =
-                               VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
-                               VRING_DESC_F_USED(!vq->avail_wrap_counter);
+                       vq->cached_flags ^=
+                               VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
                }
        } while ((cookie = cookie->next) != NULL);