dpaa2-eth: split the .ndo_xdp_xmit callback into two stages

Instead of having a function that both creates a frame descriptor from
an xdp_frame and enqueues it, split this into two stages.
Add the dpaa2_eth_xdp_create_fd that just transforms an xdp_frame into a
FD while the actual enqueue callback is called directly from the ndo for
each frame.
This is particulary useful in conjunction with bulk enqueue.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 26c2868..9a0432c 100644 (file)
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -1880,20 +1880,16 @@ static int dpaa2_eth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
        return 0;
 }
 
-static int dpaa2_eth_xdp_xmit_frame(struct net_device *net_dev,
-                                   struct xdp_frame *xdpf)
+static int dpaa2_eth_xdp_create_fd(struct net_device *net_dev,
+                                  struct xdp_frame *xdpf,
+                                  struct dpaa2_fd *fd)
 {
        struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
        struct device *dev = net_dev->dev.parent;
-       struct rtnl_link_stats64 *percpu_stats;
-       struct dpaa2_eth_drv_stats *percpu_extras;
        unsigned int needed_headroom;
        struct dpaa2_eth_swa *swa;
-       struct dpaa2_eth_fq *fq;
-       struct dpaa2_fd fd;
        void *buffer_start, *aligned_start;
        dma_addr_t addr;
-       int err, i;
 
        /* We require a minimum headroom to be able to transmit the frame.
         * Otherwise return an error and let the original net_device handle it
@@ -1902,11 +1898,8 @@ static int dpaa2_eth_xdp_xmit_frame(struct net_device *net_dev,
        if (xdpf->headroom < needed_headroom)
                return -EINVAL;
 
-       percpu_stats = this_cpu_ptr(priv->percpu_stats);
-       percpu_extras = this_cpu_ptr(priv->percpu_extras);
-
        /* Setup the FD fields */
-       memset(&fd, 0, sizeof(fd));
+       memset(fd, 0, sizeof(*fd));
 
        /* Align FD address, if possible */
        buffer_start = xdpf->data - needed_headroom;
@@ -1924,32 +1917,14 @@ static int dpaa2_eth_xdp_xmit_frame(struct net_device *net_dev,
        addr = dma_map_single(dev, buffer_start,
                              swa->xdp.dma_size,
                              DMA_BIDIRECTIONAL);
-       if (unlikely(dma_mapping_error(dev, addr))) {
-               percpu_stats->tx_dropped++;
+       if (unlikely(dma_mapping_error(dev, addr)))
                return -ENOMEM;
-       }
-
-       dpaa2_fd_set_addr(&fd, addr);
-       dpaa2_fd_set_offset(&fd, xdpf->data - buffer_start);
-       dpaa2_fd_set_len(&fd, xdpf->len);
-       dpaa2_fd_set_format(&fd, dpaa2_fd_single);
-       dpaa2_fd_set_ctrl(&fd, FD_CTRL_PTA);
-
-       fq = &priv->fq[smp_processor_id() % dpaa2_eth_queue_count(priv)];
-       for (i = 0; i < DPAA2_ETH_ENQUEUE_RETRIES; i++) {
-               err = priv->enqueue(priv, fq, &fd, 0, 1, NULL);
-               if (err != -EBUSY)
-                       break;
-       }
-       percpu_extras->tx_portal_busy += i;
-       if (unlikely(err < 0)) {
-               percpu_stats->tx_errors++;
-               /* let the Rx device handle the cleanup */
-               return err;
-       }
 
-       percpu_stats->tx_packets++;
-       percpu_stats->tx_bytes += dpaa2_fd_get_len(&fd);
+       dpaa2_fd_set_addr(fd, addr);
+       dpaa2_fd_set_offset(fd, xdpf->data - buffer_start);
+       dpaa2_fd_set_len(fd, xdpf->len);
+       dpaa2_fd_set_format(fd, dpaa2_fd_single);
+       dpaa2_fd_set_ctrl(fd, FD_CTRL_PTA);
 
        return 0;
 }
@@ -1957,6 +1932,11 @@ static int dpaa2_eth_xdp_xmit_frame(struct net_device *net_dev,
 static int dpaa2_eth_xdp_xmit(struct net_device *net_dev, int n,
                              struct xdp_frame **frames, u32 flags)
 {
+       struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+       struct dpaa2_eth_drv_stats *percpu_extras;
+       struct rtnl_link_stats64 *percpu_stats;
+       struct dpaa2_eth_fq *fq;
+       struct dpaa2_fd fd;
        int drops = 0;
        int i, err;
 
@@ -1966,14 +1946,38 @@ static int dpaa2_eth_xdp_xmit(struct net_device *net_dev, int n,
        if (!netif_running(net_dev))
                return -ENETDOWN;
 
+       percpu_stats = this_cpu_ptr(priv->percpu_stats);
+       percpu_extras = this_cpu_ptr(priv->percpu_extras);
+
        for (i = 0; i < n; i++) {
                struct xdp_frame *xdpf = frames[i];
 
-               err = dpaa2_eth_xdp_xmit_frame(net_dev, xdpf);
+               /* create the FD from the xdp_frame */
+               err = dpaa2_eth_xdp_create_fd(net_dev, xdpf, &fd);
                if (err) {
+                       percpu_stats->tx_dropped++;
                        xdp_return_frame_rx_napi(xdpf);
                        drops++;
+                       continue;
+               }
+
+               /* enqueue the newly created FD */
+               fq = &priv->fq[smp_processor_id() % dpaa2_eth_queue_count(priv)];
+               for (i = 0; i < DPAA2_ETH_ENQUEUE_RETRIES; i++) {
+                       err = priv->enqueue(priv, fq, &fd, 0, 1);
+                       if (err != -EBUSY)
+                               break;
                }
+
+               percpu_extras->tx_portal_busy += i;
+               if (unlikely(err < 0)) {
+                       percpu_stats->tx_errors++;
+                       xdp_return_frame_rx_napi(xdpf);
+                       continue;
+               }
+
+               percpu_stats->tx_packets++;
+               percpu_stats->tx_bytes += dpaa2_fd_get_len(&fd);
        }
 
        return n - drops;