atl1c: add error checking for pci_map_single functions

it is reported that code hit DMA-API errors on 3.8-rc6+,
(see https://bugzilla.redhat.com/show_bug.cgi?id=908436, and
     https://bugzilla.redhat.com/show_bug.cgi?id=908550)

this patch just adds error handler for
    pci_map_single and skb_frag_dma_map.

Signed-off-by: xiong <xiong@qca.qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index 56d3f69..0035c01 100644 (file)
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -21,7 +21,7 @@
 
 #include "atl1c.h"
 
-#define ATL1C_DRV_VERSION "1.0.1.0-NAPI"
+#define ATL1C_DRV_VERSION "1.0.1.1-NAPI"
 char atl1c_driver_name[] = "atl1c";
 char atl1c_driver_version[] = ATL1C_DRV_VERSION;
 
@@ -1652,6 +1652,7 @@ static int atl1c_alloc_rx_buffer(struct atl1c_adapter *adapter)
        u16 num_alloc = 0;
        u16 rfd_next_to_use, next_next;
        struct atl1c_rx_free_desc *rfd_desc;
+       dma_addr_t mapping;
 
        next_next = rfd_next_to_use = rfd_ring->next_to_use;
        if (++next_next == rfd_ring->count)
@@ -1678,9 +1679,18 @@ static int atl1c_alloc_rx_buffer(struct atl1c_adapter *adapter)
                ATL1C_SET_BUFFER_STATE(buffer_info, ATL1C_BUFFER_BUSY);
                buffer_info->skb = skb;
                buffer_info->length = adapter->rx_buffer_len;
-               buffer_info->dma = pci_map_single(pdev, vir_addr,
+               mapping = pci_map_single(pdev, vir_addr,
                                                buffer_info->length,
                                                PCI_DMA_FROMDEVICE);
+               if (unlikely(pci_dma_mapping_error(pdev, mapping))) {
+                       dev_kfree_skb(skb);
+                       buffer_info->skb = NULL;
+                       buffer_info->length = 0;
+                       ATL1C_SET_BUFFER_STATE(buffer_info, ATL1C_BUFFER_FREE);
+                       netif_warn(adapter, rx_err, adapter->netdev, "RX pci_map_single failed");
+                       break;
+               }
+               buffer_info->dma = mapping;
                ATL1C_SET_PCIMAP_TYPE(buffer_info, ATL1C_PCIMAP_SINGLE,
                        ATL1C_PCIMAP_FROMDEVICE);
                rfd_desc->buffer_addr = cpu_to_le64(buffer_info->dma);
@@ -2015,7 +2025,29 @@ check_sum:
        return 0;
 }
 
-static void atl1c_tx_map(struct atl1c_adapter *adapter,
+static void atl1c_tx_rollback(struct atl1c_adapter *adpt,
+                             struct atl1c_tpd_desc *first_tpd,
+                             enum atl1c_trans_queue type)
+{
+       struct atl1c_tpd_ring *tpd_ring = &adpt->tpd_ring[type];
+       struct atl1c_buffer *buffer_info;
+       struct atl1c_tpd_desc *tpd;
+       u16 first_index, index;
+
+       first_index = first_tpd - (struct atl1c_tpd_desc *)tpd_ring->desc;
+       index = first_index;
+       while (index != tpd_ring->next_to_use) {
+               tpd = ATL1C_TPD_DESC(tpd_ring, index);
+               buffer_info = &tpd_ring->buffer_info[index];
+               atl1c_clean_buffer(adpt->pdev, buffer_info, 0);
+               memset(tpd, 0, sizeof(struct atl1c_tpd_desc));
+               if (++index == tpd_ring->count)
+                       index = 0;
+       }
+       tpd_ring->next_to_use = first_index;
+}
+
+static int atl1c_tx_map(struct atl1c_adapter *adapter,
                      struct sk_buff *skb, struct atl1c_tpd_desc *tpd,
                        enum atl1c_trans_queue type)
 {
@@ -2040,7 +2072,10 @@ static void atl1c_tx_map(struct atl1c_adapter *adapter,
                buffer_info->length = map_len;
                buffer_info->dma = pci_map_single(adapter->pdev,
                                        skb->data, hdr_len, PCI_DMA_TODEVICE);
-               ATL1C_SET_BUFFER_STATE(buffer_info, ATL1C_BUFFER_BUSY);
+               if (unlikely(pci_dma_mapping_error(adapter->pdev,
+                                                  buffer_info->dma)))
+                       goto err_dma;
+
                ATL1C_SET_PCIMAP_TYPE(buffer_info, ATL1C_PCIMAP_SINGLE,
                        ATL1C_PCIMAP_TODEVICE);
                mapped_len += map_len;
@@ -2062,6 +2097,10 @@ static void atl1c_tx_map(struct atl1c_adapter *adapter,
                buffer_info->dma =
                        pci_map_single(adapter->pdev, skb->data + mapped_len,
                                        buffer_info->length, PCI_DMA_TODEVICE);
+               if (unlikely(pci_dma_mapping_error(adapter->pdev,
+                                                  buffer_info->dma)))
+                       goto err_dma;
+
                ATL1C_SET_BUFFER_STATE(buffer_info, ATL1C_BUFFER_BUSY);
                ATL1C_SET_PCIMAP_TYPE(buffer_info, ATL1C_PCIMAP_SINGLE,
                        ATL1C_PCIMAP_TODEVICE);
@@ -2083,6 +2122,9 @@ static void atl1c_tx_map(struct atl1c_adapter *adapter,
                                                    frag, 0,
                                                    buffer_info->length,
                                                    DMA_TO_DEVICE);
+               if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma))
+                       goto err_dma;
+
                ATL1C_SET_BUFFER_STATE(buffer_info, ATL1C_BUFFER_BUSY);
                ATL1C_SET_PCIMAP_TYPE(buffer_info, ATL1C_PCIMAP_PAGE,
                        ATL1C_PCIMAP_TODEVICE);
@@ -2095,6 +2137,13 @@ static void atl1c_tx_map(struct atl1c_adapter *adapter,
        /* The last buffer info contain the skb address,
           so it will be free after unmap */
        buffer_info->skb = skb;
+
+       return 0;
+
+err_dma:
+       buffer_info->dma = 0;
+       buffer_info->length = 0;
+       return -1;
 }
 
 static void atl1c_tx_queue(struct atl1c_adapter *adapter, struct sk_buff *skb,
@@ -2157,10 +2206,18 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,
        if (skb_network_offset(skb) != ETH_HLEN)
                tpd->word1 |= 1 << TPD_ETH_TYPE_SHIFT; /* Ethernet frame */
 
-       atl1c_tx_map(adapter, skb, tpd, type);
-       atl1c_tx_queue(adapter, skb, tpd, type);
+       if (atl1c_tx_map(adapter, skb, tpd, type) < 0) {
+               netif_info(adapter, tx_done, adapter->netdev,
+                          "tx-skb droppted due to dma error\n");
+               /* roll back tpd/buffer */
+               atl1c_tx_rollback(adapter, tpd, type);
+               spin_unlock_irqrestore(&adapter->tx_lock, flags);
+               dev_kfree_skb(skb);
+       } else {
+               atl1c_tx_queue(adapter, skb, tpd, type);
+               spin_unlock_irqrestore(&adapter->tx_lock, flags);
+       }
 
-       spin_unlock_irqrestore(&adapter->tx_lock, flags);
        return NETDEV_TX_OK;
 }