sky2: handle dma mapping errors

On non-x86 platforms it is possible to run out of DMA mapping resources.
The driver was ignoring this and could cause corruptions.

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

1 files changed, 56 insertions, 8 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index db925085c185..8b9b88457267 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1068,13 +1068,16 @@ static void sky2_rx_submit(struct sky2_port *sky2,
 }
 
 
-static void sky2_rx_map_skb(struct pci_dev *pdev, struct rx_ring_info *re,
+static int sky2_rx_map_skb(struct pci_dev *pdev, struct rx_ring_info *re,
                             unsigned size)
 {
         struct sk_buff *skb = re->skb;
         int i;
 
         re->data_addr = pci_map_single(pdev, skb->data, size, PCI_DMA_FROMDEVICE);
+        if (unlikely(pci_dma_mapping_error(pdev, re->data_addr)))
+                return -EIO;
+
         pci_unmap_len_set(re, data_size, size);
 
         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
@@ -1083,6 +1086,7 @@ static void sky2_rx_map_skb(struct pci_dev *pdev, struct rx_ring_info *re,
                                                 skb_shinfo(skb)->frags[i].page_offset,
                                                 skb_shinfo(skb)->frags[i].size,
                                                 PCI_DMA_FROMDEVICE);
+        return 0;
 }
 
 static void sky2_rx_unmap_skb(struct pci_dev *pdev, struct rx_ring_info *re)
@@ -1354,7 +1358,12 @@ static int sky2_rx_start(struct sky2_port *sky2)
                 if (!re->skb)
                         goto nomem;
 
-                sky2_rx_map_skb(hw->pdev, re, sky2->rx_data_size);
+                if (sky2_rx_map_skb(hw->pdev, re, sky2->rx_data_size)) {
+                        dev_kfree_skb(re->skb);
+                        re->skb = NULL;
+                        goto nomem;
+                }
+
                 sky2_rx_submit(sky2, re);
         }
 
@@ -1547,7 +1556,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         struct sky2_hw *hw = sky2->hw;
         struct sky2_tx_le *le = NULL;
         struct tx_ring_info *re;
-        unsigned i, len;
+        unsigned i, len, first_slot;
         dma_addr_t mapping;
         u16 mss;
         u8 ctrl;
@@ -1555,13 +1564,17 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
         if (unlikely(tx_avail(sky2) < tx_le_req(skb)))
                 return NETDEV_TX_BUSY;
 
-        if (unlikely(netif_msg_tx_queued(sky2)))
-                printk(KERN_DEBUG "%s: tx queued, slot %u, len %d\n",
-                       dev->name, sky2->tx_prod, skb->len);
-
         len = skb_headlen(skb);
         mapping = pci_map_single(hw->pdev, skb->data, len, PCI_DMA_TODEVICE);
 
+        if (pci_dma_mapping_error(hw->pdev, mapping))
+                goto mapping_error;
+
+        first_slot = sky2->tx_prod;
+        if (unlikely(netif_msg_tx_queued(sky2)))
+                printk(KERN_DEBUG "%s: tx queued, slot %u, len %d\n",
+                       dev->name, first_slot, skb->len);
+
         /* Send high bits if needed */
         if (sizeof(dma_addr_t) > sizeof(u32)) {
                 le = get_tx_le(sky2);
@@ -1648,6 +1661,9 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
                 mapping = pci_map_page(hw->pdev, frag->page, frag->page_offset,
                                        frag->size, PCI_DMA_TODEVICE);
 
+                if (pci_dma_mapping_error(hw->pdev, mapping))
+                        goto mapping_unwind;
+
                 if (sizeof(dma_addr_t) > sizeof(u32)) {
                         le = get_tx_le(sky2);
                         le->addr = cpu_to_le32(upper_32_bits(mapping));
@@ -1676,6 +1692,34 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 
         dev->trans_start = jiffies;
         return NETDEV_TX_OK;
+
+mapping_unwind:
+        for (i = first_slot; i != sky2->tx_prod; i = RING_NEXT(i, TX_RING_SIZE)) {
+                le = sky2->tx_le + i;
+                re = sky2->tx_ring + i;
+
+                switch(le->opcode & ~HW_OWNER) {
+                case OP_LARGESEND:
+                case OP_PACKET:
+                        pci_unmap_single(hw->pdev,
+                                         pci_unmap_addr(re, mapaddr),
+                                         pci_unmap_len(re, maplen),
+                                         PCI_DMA_TODEVICE);
+                        break;
+                case OP_BUFFER:
+                        pci_unmap_page(hw->pdev, pci_unmap_addr(re, mapaddr),
+                                       pci_unmap_len(re, maplen),
+                                       PCI_DMA_TODEVICE);
+                        break;
+                }
+        }
+
+        sky2->tx_prod = first_slot;
+mapping_error:
+        if (net_ratelimit())
+                dev_warn(&hw->pdev->dev, "%s: tx mapping error\n", dev->name);
+        dev_kfree_skb(skb);
+        return NETDEV_TX_OK;
 }
 
 /*
@@ -2191,7 +2235,11 @@ static struct sk_buff *receive_new(struct sky2_port *sky2,
 
         prefetch(skb->data);
         re->skb = nskb;
-        sky2_rx_map_skb(sky2->hw->pdev, re, hdr_space);
+        if (sky2_rx_map_skb(sky2->hw->pdev, re, hdr_space)) {
+                dev_kfree_skb(nskb);
+                re->skb = skb;
+                return NULL;
+        }
 
         if (skb_shinfo(skb)->nr_frags)
                 skb_put_frags(skb, hdr_space, length);