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>

1 files changed, 64 insertions, 7 deletions

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index 56d3f697e0c7..0035c01660b6 100644
--- 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;
 }