net: ll_temac: Add more error handling of dma_map_single() calls

This adds error handling to the remaining dma_map_single() calls, so that
behavior is well defined if/when we run out of DMA memory.

Fixes: 92744989533c ("net: add Xilinx ll_temac device driver")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 996004e..c368c39 100644 (file)
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -367,6 +367,8 @@ static int temac_dma_bd_init(struct net_device *ndev)
                skb_dma_addr = dma_map_single(ndev->dev.parent, skb->data,
                                              XTE_MAX_JUMBO_FRAME_SIZE,
                                              DMA_FROM_DEVICE);
+               if (dma_mapping_error(ndev->dev.parent, skb_dma_addr))
+                       goto out;
                lp->rx_bd_v[i].phys = cpu_to_be32(skb_dma_addr);
                lp->rx_bd_v[i].len = cpu_to_be32(XTE_MAX_JUMBO_FRAME_SIZE);
                lp->rx_bd_v[i].app0 = cpu_to_be32(STS_CTRL_APP0_IRQONEND);
@@ -863,12 +865,13 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        skb_dma_addr = dma_map_single(ndev->dev.parent, skb->data,
                                      skb_headlen(skb), DMA_TO_DEVICE);
        cur_p->len = cpu_to_be32(skb_headlen(skb));
+       if (WARN_ON_ONCE(dma_mapping_error(ndev->dev.parent, skb_dma_addr)))
+               return NETDEV_TX_BUSY;
        cur_p->phys = cpu_to_be32(skb_dma_addr);
        ptr_to_txbd((void *)skb, cur_p);
 
        for (ii = 0; ii < num_frag; ii++) {
-               lp->tx_bd_tail++;
-               if (lp->tx_bd_tail >= TX_BD_NUM)
+               if (++lp->tx_bd_tail >= TX_BD_NUM)
                        lp->tx_bd_tail = 0;
 
                cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
@@ -876,6 +879,25 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                                              skb_frag_address(frag),
                                              skb_frag_size(frag),
                                              DMA_TO_DEVICE);
+               if (dma_mapping_error(ndev->dev.parent, skb_dma_addr)) {
+                       if (--lp->tx_bd_tail < 0)
+                               lp->tx_bd_tail = TX_BD_NUM - 1;
+                       cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
+                       while (--ii >= 0) {
+                               --frag;
+                               dma_unmap_single(ndev->dev.parent,
+                                                be32_to_cpu(cur_p->phys),
+                                                skb_frag_size(frag),
+                                                DMA_TO_DEVICE);
+                               if (--lp->tx_bd_tail < 0)
+                                       lp->tx_bd_tail = TX_BD_NUM - 1;
+                               cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
+                       }
+                       dma_unmap_single(ndev->dev.parent,
+                                        be32_to_cpu(cur_p->phys),
+                                        skb_headlen(skb), DMA_TO_DEVICE);
+                       return NETDEV_TX_BUSY;
+               }
                cur_p->phys = cpu_to_be32(skb_dma_addr);
                cur_p->len = cpu_to_be32(skb_frag_size(frag));
                cur_p->app0 = 0;