be2net: handle dma mapping errors in Tx path

Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 3 deletions

diff --git a/drivers/net/benet/be_main.c b/drivers/net/benet/be_main.c
index 43e8032f9236..0800c6363908 100644
--- a/drivers/net/benet/be_main.c
+++ b/drivers/net/benet/be_main.c
@@ -386,26 +386,48 @@ static void wrb_fill_hdr(struct be_eth_hdr_wrb *hdr, struct sk_buff *skb,
         AMAP_SET_BITS(struct amap_eth_hdr_wrb, len, hdr, len);
 }
 
+static void unmap_tx_frag(struct pci_dev *pdev, struct be_eth_wrb *wrb,
+                bool unmap_single)
+{
+        dma_addr_t dma;
+
+        be_dws_le_to_cpu(wrb, sizeof(*wrb));
+
+        dma = (u64)wrb->frag_pa_hi << 32 | (u64)wrb->frag_pa_lo;
+        if (dma != 0) {
+                if (unmap_single)
+                        pci_unmap_single(pdev, dma, wrb->frag_len,
+                                PCI_DMA_TODEVICE);
+                else
+                        pci_unmap_page(pdev, dma, wrb->frag_len,
+                                PCI_DMA_TODEVICE);
+        }
+}
 
 static int make_tx_wrbs(struct be_adapter *adapter,
                 struct sk_buff *skb, u32 wrb_cnt, bool dummy_wrb)
 {
-        u64 busaddr;
-        u32 i, copied = 0;
+        dma_addr_t busaddr;
+        int i, copied = 0;
         struct pci_dev *pdev = adapter->pdev;
         struct sk_buff *first_skb = skb;
         struct be_queue_info *txq = &adapter->tx_obj.q;
         struct be_eth_wrb *wrb;
         struct be_eth_hdr_wrb *hdr;
+        bool map_single = false;
+        u16 map_head;
 
         hdr = queue_head_node(txq);
-        atomic_add(wrb_cnt, &txq->used);
         queue_head_inc(txq);
+        map_head = txq->head;
 
         if (skb->len > skb->data_len) {
                 int len = skb->len - skb->data_len;
                 busaddr = pci_map_single(pdev, skb->data, len,
                                          PCI_DMA_TODEVICE);
+                if (pci_dma_mapping_error(pdev, busaddr))
+                        goto dma_err;
+                map_single = true;
                 wrb = queue_head_node(txq);
                 wrb_fill(wrb, busaddr, len);
                 be_dws_cpu_to_le(wrb, sizeof(*wrb));
@@ -419,6 +441,8 @@ static int make_tx_wrbs(struct be_adapter *adapter,
                 busaddr = pci_map_page(pdev, frag->page,
                                        frag->page_offset,
                                        frag->size, PCI_DMA_TODEVICE);
+                if (pci_dma_mapping_error(pdev, busaddr))
+                        goto dma_err;
                 wrb = queue_head_node(txq);
                 wrb_fill(wrb, busaddr, frag->size);
                 be_dws_cpu_to_le(wrb, sizeof(*wrb));
@@ -438,6 +462,16 @@ static int make_tx_wrbs(struct be_adapter *adapter,
         be_dws_cpu_to_le(hdr, sizeof(*hdr));
 
         return copied;
+dma_err:
+        txq->head = map_head;
+        while (copied) {
+                wrb = queue_head_node(txq);
+                unmap_tx_frag(pdev, wrb, map_single);
+                map_single = false;
+                copied -= wrb->frag_len;
+                queue_head_inc(txq);
+        }
+        return 0;
 }
 
 static netdev_tx_t be_xmit(struct sk_buff *skb,
@@ -462,6 +496,7 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
                  * *BEFORE* ringing the tx doorbell, so that we serialze the
                  * tx compls of the current transmit which'll wake up the queue
                  */
+                atomic_add(wrb_cnt, &txq->used);
                 if ((BE_MAX_TX_FRAG_COUNT + atomic_read(&txq->used)) >=
                                                                 txq->len) {
                         netif_stop_queue(netdev);