via-rhine: allocate and map receive buffer in a single transaction

It's used to initialize the receive ring but it will actually shine when
the receive poll code is reworked.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/via/via-rhine.c b/drivers/net/ethernet/via/via-rhine.c
index 88b45c7..aa398ea 100644 (file)
--- a/drivers/net/ethernet/via/via-rhine.c
+++ b/drivers/net/ethernet/via/via-rhine.c
@@ -1213,12 +1213,47 @@ static void free_ring(struct net_device* dev)
 
 }
 
-static void alloc_rbufs(struct net_device *dev)
+struct rhine_skb_dma {
+       struct sk_buff *skb;
+       dma_addr_t dma;
+};
+
+static inline int rhine_skb_dma_init(struct net_device *dev,
+                                    struct rhine_skb_dma *sd)
 {
        struct rhine_private *rp = netdev_priv(dev);
        struct device *hwdev = dev->dev.parent;
+       const int size = rp->rx_buf_sz;
+
+       sd->skb = netdev_alloc_skb(dev, size);
+       if (!sd->skb)
+               return -ENOMEM;
+
+       sd->dma = dma_map_single(hwdev, sd->skb->data, size, DMA_FROM_DEVICE);
+       if (unlikely(dma_mapping_error(hwdev, sd->dma))) {
+               netif_err(rp, drv, dev, "Rx DMA mapping failure\n");
+               dev_kfree_skb_any(sd->skb);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+static inline void rhine_skb_dma_nic_store(struct rhine_private *rp,
+                                          struct rhine_skb_dma *sd, int entry)
+{
+       rp->rx_skbuff_dma[entry] = sd->dma;
+       rp->rx_skbuff[entry] = sd->skb;
+
+       rp->rx_ring[entry].addr = cpu_to_le32(sd->dma);
+       dma_wmb();
+}
+
+static void alloc_rbufs(struct net_device *dev)
+{
+       struct rhine_private *rp = netdev_priv(dev);
        dma_addr_t next;
-       int i;
+       int rc, i;
 
        rp->dirty_rx = rp->cur_rx = 0;
 
@@ -1239,20 +1274,14 @@ static void alloc_rbufs(struct net_device *dev)
 
        /* Fill in the Rx buffers.  Handle allocation failure gracefully. */
        for (i = 0; i < RX_RING_SIZE; i++) {
-               struct sk_buff *skb = netdev_alloc_skb(dev, rp->rx_buf_sz);
-               rp->rx_skbuff[i] = skb;
-               if (skb == NULL)
-                       break;
+               struct rhine_skb_dma sd;
 
-               rp->rx_skbuff_dma[i] =
-                       dma_map_single(hwdev, skb->data, rp->rx_buf_sz,
-                                      DMA_FROM_DEVICE);
-               if (dma_mapping_error(hwdev, rp->rx_skbuff_dma[i])) {
-                       rp->rx_skbuff_dma[i] = 0;
-                       dev_kfree_skb(skb);
+               rc = rhine_skb_dma_init(dev, &sd);
+               if (rc < 0)
                        break;
-               }
-               rp->rx_ring[i].addr = cpu_to_le32(rp->rx_skbuff_dma[i]);
+
+               rhine_skb_dma_nic_store(rp, &sd, i);
+
                rp->rx_ring[i].rx_status = cpu_to_le32(DescOwn);
        }
        rp->dirty_rx = (unsigned int)(i - RX_RING_SIZE);