skge: check for PCI dma mapping errors

Driver should check for mapping errors.
Machines with limited DMA maps may return an error when a PCI map is
requested (not an issue on standard x86).

Also use upper/lower 32 bits macros for clarity.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/marvell/skge.c b/drivers/net/ethernet/marvell/skge.c
index f580f05..299c33b 100644 (file)
--- a/drivers/net/ethernet/marvell/skge.c
+++ b/drivers/net/ethernet/marvell/skge.c
@@ -931,17 +931,20 @@ static int skge_ring_alloc(struct skge_ring *ring, void *vaddr, u32 base)
 }
 
 /* Allocate and setup a new buffer for receiving */
-static void skge_rx_setup(struct skge_port *skge, struct skge_element *e,
-                         struct sk_buff *skb, unsigned int bufsize)
+static int skge_rx_setup(struct pci_dev *pdev,
+                        struct skge_element *e,
+                        struct sk_buff *skb, unsigned int bufsize)
 {
        struct skge_rx_desc *rd = e->desc;
-       u64 map;
+       dma_addr_t map;
 
-       map = pci_map_single(skge->hw->pdev, skb->data, bufsize,
+       map = pci_map_single(pdev, skb->data, bufsize,
                             PCI_DMA_FROMDEVICE);
+       if (pci_dma_mapping_error(pdev, map))
+               goto mapping_error;
 
-       rd->dma_lo = map;
-       rd->dma_hi = map >> 32;
+       rd->dma_lo = lower_32_bits(map);
+       rd->dma_hi = upper_32_bits(map);
        e->skb = skb;
        rd->csum1_start = ETH_HLEN;
        rd->csum2_start = ETH_HLEN;
@@ -953,6 +956,13 @@ static void skge_rx_setup(struct skge_port *skge, struct skge_element *e,
        rd->control = BMU_OWN | BMU_STF | BMU_IRQ_EOF | BMU_TCP_CHECK | bufsize;
        dma_unmap_addr_set(e, mapaddr, map);
        dma_unmap_len_set(e, maplen, bufsize);
+       return 0;
+
+mapping_error:
+       if (net_ratelimit())
+               dev_warn(&pdev->dev, "%s: rx mapping error\n",
+                        skb->dev->name);
+       return -EIO;
 }
 
 /* Resume receiving using existing skb,
@@ -1014,7 +1024,11 @@ static int skge_rx_fill(struct net_device *dev)
                        return -ENOMEM;
 
                skb_reserve(skb, NET_IP_ALIGN);
-               skge_rx_setup(skge, e, skb, skge->rx_buf_size);
+               if (skge_rx_setup(skge->hw->pdev, e, skb, skge->rx_buf_size)) {
+                       kfree_skb(skb);
+                       return -ENOMEM;
+               }
+
        } while ((e = e->next) != ring->start);
 
        ring->to_clean = ring->start;
@@ -2729,7 +2743,7 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
        struct skge_tx_desc *td;
        int i;
        u32 control, len;
-       u64 map;
+       dma_addr_t map;
 
        if (skb_padto(skb, ETH_ZLEN))
                return NETDEV_TX_OK;
@@ -2743,11 +2757,14 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
        e->skb = skb;
        len = skb_headlen(skb);
        map = pci_map_single(hw->pdev, skb->data, len, PCI_DMA_TODEVICE);
+       if (pci_dma_mapping_error(hw->pdev, map))
+               goto mapping_error;
+
        dma_unmap_addr_set(e, mapaddr, map);
        dma_unmap_len_set(e, maplen, len);
 
-       td->dma_lo = map;
-       td->dma_hi = map >> 32;
+       td->dma_lo = lower_32_bits(map);
+       td->dma_hi = upper_32_bits(map);
 
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                const int offset = skb_checksum_start_offset(skb);
@@ -2778,14 +2795,16 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
 
                        map = skb_frag_dma_map(&hw->pdev->dev, frag, 0,
                                               skb_frag_size(frag), DMA_TO_DEVICE);
+                       if (dma_mapping_error(&hw->pdev->dev, map))
+                               goto mapping_unwind;
 
                        e = e->next;
                        e->skb = skb;
                        tf = e->desc;
                        BUG_ON(tf->control & BMU_OWN);
 
-                       tf->dma_lo = map;
-                       tf->dma_hi = (u64) map >> 32;
+                       tf->dma_lo = lower_32_bits(map);
+                       tf->dma_hi = upper_32_bits(map);
                        dma_unmap_addr_set(e, mapaddr, map);
                        dma_unmap_len_set(e, maplen, skb_frag_size(frag));
 
@@ -2813,6 +2832,28 @@ static netdev_tx_t skge_xmit_frame(struct sk_buff *skb,
        }
 
        return NETDEV_TX_OK;
+
+mapping_unwind:
+       /* unroll any pages that were already mapped.  */
+       if (e != skge->tx_ring.to_use) {
+               struct skge_element *u;
+
+               for (u = skge->tx_ring.to_use->next; u != e; u = u->next)
+                       pci_unmap_page(hw->pdev, dma_unmap_addr(u, mapaddr),
+                                      dma_unmap_len(u, maplen),
+                                      PCI_DMA_TODEVICE);
+               e = skge->tx_ring.to_use;
+       }
+       /* undo the mapping for the skb header */
+       pci_unmap_single(hw->pdev, dma_unmap_addr(e, mapaddr),
+                        dma_unmap_len(e, maplen),
+                        PCI_DMA_TODEVICE);
+mapping_error:
+       /* mapping error causes error message and packet to be discarded. */
+       if (net_ratelimit())
+               dev_warn(&hw->pdev->dev, "%s: tx mapping error\n", dev->name);
+       dev_kfree_skb(skb);
+       return NETDEV_TX_OK;
 }
 
 
@@ -3060,13 +3101,17 @@ static struct sk_buff *skge_rx_get(struct net_device *dev,
                if (!nskb)
                        goto resubmit;
 
+               if (unlikely(skge_rx_setup(skge->hw->pdev, e, nskb, skge->rx_buf_size))) {
+                       dev_kfree_skb(nskb);
+                       goto resubmit;
+               }
+
                pci_unmap_single(skge->hw->pdev,
                                 dma_unmap_addr(e, mapaddr),
                                 dma_unmap_len(e, maplen),
                                 PCI_DMA_FROMDEVICE);
                skb = e->skb;
                prefetch(skb->data);
-               skge_rx_setup(skge, e, nskb, skge->rx_buf_size);
        }
 
        skb_put(skb, len);