sh_eth: Fix DMA-API usage for RX buffers

- Use the return value of dma_map_single(), rather than calling
  virt_to_page() separately
- Check for mapping failue
- Call dma_unmap_single() rather than dma_sync_single_for_cpu()

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 4a085da57188..04283fe0e6a7 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1123,6 +1123,7 @@ static void sh_eth_ring_format(struct net_device *ndev)
         int rx_ringsize = sizeof(*rxdesc) * mdp->num_rx_ring;
         int tx_ringsize = sizeof(*txdesc) * mdp->num_tx_ring;
         int skbuff_size = mdp->rx_buf_sz + SH_ETH_RX_ALIGN - 1;
+        dma_addr_t dma_addr;
 
         mdp->cur_rx = 0;
         mdp->cur_tx = 0;
@@ -1136,7 +1137,6 @@ static void sh_eth_ring_format(struct net_device *ndev)
                 /* skb */
                 mdp->rx_skbuff[i] = NULL;
                 skb = netdev_alloc_skb(ndev, skbuff_size);
-                mdp->rx_skbuff[i] = skb;
                 if (skb == NULL)
                         break;
                 sh_eth_set_receive_align(skb);
@@ -1145,9 +1145,15 @@ static void sh_eth_ring_format(struct net_device *ndev)
                 rxdesc = &mdp->rx_ring[i];
                 /* The size of the buffer is a multiple of 16 bytes. */
                 rxdesc->buffer_length = ALIGN(mdp->rx_buf_sz, 16);
-                dma_map_single(&ndev->dev, skb->data, rxdesc->buffer_length,
-                               DMA_FROM_DEVICE);
-                rxdesc->addr = virt_to_phys(skb->data);
+                dma_addr = dma_map_single(&ndev->dev, skb->data,
+                                          rxdesc->buffer_length,
+                                          DMA_FROM_DEVICE);
+                if (dma_mapping_error(&ndev->dev, dma_addr)) {
+                        kfree_skb(skb);
+                        break;
+                }
+                mdp->rx_skbuff[i] = skb;
+                rxdesc->addr = dma_addr;
                 rxdesc->status = cpu_to_edmac(mdp, RD_RACT | RD_RFP);
 
                 /* Rx descriptor address set */
@@ -1432,6 +1438,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
         u16 pkt_len = 0;
         u32 desc_status;
         int skbuff_size = mdp->rx_buf_sz + SH_ETH_RX_ALIGN - 1;
+        dma_addr_t dma_addr;
 
         boguscnt = min(boguscnt, *quota);
         limit = boguscnt;
@@ -1479,9 +1486,9 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
                         mdp->rx_skbuff[entry] = NULL;
                         if (mdp->cd->rpadir)
                                 skb_reserve(skb, NET_IP_ALIGN);
-                        dma_sync_single_for_cpu(&ndev->dev, rxdesc->addr,
-                                                ALIGN(mdp->rx_buf_sz, 16),
-                                                DMA_FROM_DEVICE);
+                        dma_unmap_single(&ndev->dev, rxdesc->addr,
+                                         ALIGN(mdp->rx_buf_sz, 16),
+                                         DMA_FROM_DEVICE);
                         skb_put(skb, pkt_len);
                         skb->protocol = eth_type_trans(skb, ndev);
                         netif_receive_skb(skb);
@@ -1501,15 +1508,20 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)
 
                 if (mdp->rx_skbuff[entry] == NULL) {
                         skb = netdev_alloc_skb(ndev, skbuff_size);
-                        mdp->rx_skbuff[entry] = skb;
                         if (skb == NULL)
                                 break;  /* Better luck next round. */
                         sh_eth_set_receive_align(skb);
-                        dma_map_single(&ndev->dev, skb->data,
-                                       rxdesc->buffer_length, DMA_FROM_DEVICE);
+                        dma_addr = dma_map_single(&ndev->dev, skb->data,
+                                                  rxdesc->buffer_length,
+                                                  DMA_FROM_DEVICE);
+                        if (dma_mapping_error(&ndev->dev, dma_addr)) {
+                                kfree_skb(skb);
+                                break;
+                        }
+                        mdp->rx_skbuff[entry] = skb;
 
                         skb_checksum_none_assert(skb);
-                        rxdesc->addr = virt_to_phys(skb->data);
+                        rxdesc->addr = dma_addr;
                 }
                 if (entry >= mdp->num_rx_ring - 1)
                         rxdesc->status |=