S2IO: Checking for the return value of pci map function

 - Checking for the return value of pci map function
 - Implemented Francois Romieu's comments on eliminating code duplication
   using goto
 - Implemented Francois Romieu's comments on using a temporary variable for
   accessing statistics structure

Signed-off-by: Veena Parat <veena.parat@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 79 insertions, 3 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 724b44360a47..ce3a6d9b13c8 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -282,6 +282,7 @@ static char ethtool_driver_stats_keys[][ETH_GSTRING_LEN] = {
         ("lro_flush_due_to_max_pkts"),
         ("lro_avg_aggr_pkts"),
         ("mem_alloc_fail_cnt"),
+        ("pci_map_fail_cnt"),
         ("watchdog_timer_cnt"),
         ("mem_allocated"),
         ("mem_freed"),
@@ -2271,6 +2272,7 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
         u64 Buffer0_ptr = 0, Buffer1_ptr = 0;
         struct RxD1 *rxdp1;
         struct RxD3 *rxdp3;
+        struct swStat *stats = &nic->mac_control.stats_info->sw_stat;
 
         mac_control = &nic->mac_control;
         config = &nic->config;
@@ -2360,6 +2362,11 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
                         rxdp1->Buffer0_ptr = pci_map_single
                             (nic->pdev, skb->data, size - NET_IP_ALIGN,
                                 PCI_DMA_FROMDEVICE);
+                        if( (rxdp1->Buffer0_ptr == 0) ||
+                                (rxdp1->Buffer0_ptr ==
+                                DMA_ERROR_CODE))
+                                goto pci_map_failed;
+
                         rxdp->Control_2 = 
                                 SET_BUFFER0_SIZE_1(size - NET_IP_ALIGN);
 
@@ -2395,6 +2402,10 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
                                 pci_dma_sync_single_for_device(nic->pdev,
                                 (dma_addr_t) rxdp3->Buffer0_ptr,
                                     BUF0_LEN, PCI_DMA_FROMDEVICE);
+                        if( (rxdp3->Buffer0_ptr == 0) ||
+                                (rxdp3->Buffer0_ptr == DMA_ERROR_CODE))
+                                goto pci_map_failed;
+
                         rxdp->Control_2 = SET_BUFFER0_SIZE_3(BUF0_LEN);
                         if (nic->rxd_mode == RXD_MODE_3B) {
                                 /* Two buffer mode */
@@ -2407,12 +2418,22 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
                                 (nic->pdev, skb->data, dev->mtu + 4,
                                                 PCI_DMA_FROMDEVICE);
 
-                                /* Buffer-1 will be dummy buffer. Not used */
-                                if (!(rxdp3->Buffer1_ptr)) {
-                                        rxdp3->Buffer1_ptr =
+                                if( (rxdp3->Buffer2_ptr == 0) ||
+                                        (rxdp3->Buffer2_ptr == DMA_ERROR_CODE))
+                                        goto pci_map_failed;
+
+                                rxdp3->Buffer1_ptr =
                                                 pci_map_single(nic->pdev,
                                                 ba->ba_1, BUF1_LEN,
                                                 PCI_DMA_FROMDEVICE);
+                                if( (rxdp3->Buffer1_ptr == 0) ||
+                                        (rxdp3->Buffer1_ptr == DMA_ERROR_CODE)) {
+                                        pci_unmap_single
+                                                (nic->pdev,
+                                                (dma_addr_t)skb->data,
+                                                dev->mtu + 4,
+                                                PCI_DMA_FROMDEVICE);
+                                        goto pci_map_failed;
                                 }
                                 rxdp->Control_2 |= SET_BUFFER1_SIZE_3(1);
                                 rxdp->Control_2 |= SET_BUFFER2_SIZE_3
@@ -2451,6 +2472,11 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
         }
 
         return SUCCESS;
+pci_map_failed:
+        stats->pci_map_fail_cnt++;
+        stats->mem_freed += skb->truesize;
+        dev_kfree_skb_irq(skb);
+        return -ENOMEM;
 }
 
 static void free_rxd_blk(struct s2io_nic *sp, int ring_no, int blk)
@@ -3882,6 +3908,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         struct mac_info *mac_control;
         struct config_param *config;
         int offload_type;
+        struct swStat *stats = &sp->mac_control.stats_info->sw_stat;
 
         mac_control = &sp->mac_control;
         config = &sp->config;
@@ -3966,11 +3993,18 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
                 txdp->Buffer_Pointer = pci_map_single(sp->pdev,
                                         sp->ufo_in_band_v,
                                         sizeof(u64), PCI_DMA_TODEVICE);
+                if((txdp->Buffer_Pointer == 0) ||
+                        (txdp->Buffer_Pointer == DMA_ERROR_CODE))
+                        goto pci_map_failed;
                 txdp++;
         }
 
         txdp->Buffer_Pointer = pci_map_single
             (sp->pdev, skb->data, frg_len, PCI_DMA_TODEVICE);
+        if((txdp->Buffer_Pointer == 0) ||
+                (txdp->Buffer_Pointer == DMA_ERROR_CODE))
+                goto pci_map_failed;
+
         txdp->Host_Control = (unsigned long) skb;
         txdp->Control_1 |= TXD_BUFFER0_SIZE(frg_len);
         if (offload_type == SKB_GSO_UDP)
@@ -4027,6 +4061,13 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         spin_unlock_irqrestore(&sp->tx_lock, flags);
 
         return 0;
+pci_map_failed:
+        stats->pci_map_fail_cnt++;
+        netif_stop_queue(dev);
+        stats->mem_freed += skb->truesize;
+        dev_kfree_skb(skb);
+        spin_unlock_irqrestore(&sp->tx_lock, flags);
+        return 0;
 }
 
 static void
@@ -5769,6 +5810,7 @@ static void s2io_get_ethtool_stats(struct net_device *dev,
         else
                 tmp_stats[i++] = 0;
         tmp_stats[i++] = stat_info->sw_stat.mem_alloc_fail_cnt;
+        tmp_stats[i++] = stat_info->sw_stat.pci_map_fail_cnt;
         tmp_stats[i++] = stat_info->sw_stat.watchdog_timer_cnt;
         tmp_stats[i++] = stat_info->sw_stat.mem_allocated;
         tmp_stats[i++] = stat_info->sw_stat.mem_freed;
@@ -6112,6 +6154,7 @@ static int set_rxd_buffer_pointer(struct s2io_nic *sp, struct RxD_t *rxdp,
                                 u64 *temp2, int size)
 {
         struct net_device *dev = sp->dev;
+        struct swStat *stats = &sp->mac_control.stats_info->sw_stat;
 
         if ((sp->rxd_mode == RXD_MODE_1) && (rxdp->Host_Control == 0)) {
                 struct RxD1 *rxdp1 = (struct RxD1 *)rxdp;
@@ -6144,6 +6187,10 @@ static int set_rxd_buffer_pointer(struct s2io_nic *sp, struct RxD_t *rxdp,
                                 pci_map_single( sp->pdev, (*skb)->data,
                                         size - NET_IP_ALIGN,
                                         PCI_DMA_FROMDEVICE);
+                        if( (rxdp1->Buffer0_ptr == 0) ||
+                                (rxdp1->Buffer0_ptr == DMA_ERROR_CODE)) {
+                                goto memalloc_failed;
+                        }
                         rxdp->Host_Control = (unsigned long) (*skb);
                 }
         } else if ((sp->rxd_mode == RXD_MODE_3B) && (rxdp->Host_Control == 0)) {
@@ -6169,19 +6216,43 @@ static int set_rxd_buffer_pointer(struct s2io_nic *sp, struct RxD_t *rxdp,
                                 pci_map_single(sp->pdev, (*skb)->data,
                                                dev->mtu + 4,
                                                PCI_DMA_FROMDEVICE);
+                        if( (rxdp3->Buffer2_ptr == 0) ||
+                                (rxdp3->Buffer2_ptr == DMA_ERROR_CODE)) {
+                                goto memalloc_failed;
+                        }
                         rxdp3->Buffer0_ptr = *temp0 =
                                 pci_map_single( sp->pdev, ba->ba_0, BUF0_LEN,
                                                 PCI_DMA_FROMDEVICE);
+                        if( (rxdp3->Buffer0_ptr == 0) ||
+                                (rxdp3->Buffer0_ptr == DMA_ERROR_CODE)) {
+                                pci_unmap_single (sp->pdev,
+                                        (dma_addr_t)(*skb)->data,
+                                        dev->mtu + 4, PCI_DMA_FROMDEVICE);
+                                goto memalloc_failed;
+                        }
                         rxdp->Host_Control = (unsigned long) (*skb);
 
                         /* Buffer-1 will be dummy buffer not used */
                         rxdp3->Buffer1_ptr = *temp1 =
                                 pci_map_single(sp->pdev, ba->ba_1, BUF1_LEN,
                                                 PCI_DMA_FROMDEVICE);
+                        if( (rxdp3->Buffer1_ptr == 0) ||
+                                (rxdp3->Buffer1_ptr == DMA_ERROR_CODE)) {
+                                pci_unmap_single (sp->pdev,
+                                        (dma_addr_t)(*skb)->data,
+                                        dev->mtu + 4, PCI_DMA_FROMDEVICE);
+                                goto memalloc_failed;
+                        }
                 }
         }
         return 0;
+        memalloc_failed:
+                stats->pci_map_fail_cnt++;
+                stats->mem_freed += (*skb)->truesize;
+                dev_kfree_skb(*skb);
+                return -ENOMEM;
 }
+
 static void set_rxd_buffer_size(struct s2io_nic *sp, struct RxD_t *rxdp,
                                 int size)
 {
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index aa5428c4368e..92983ee7df8c 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -74,6 +74,10 @@ static int debug_level = ERR_DBG;
 /* DEBUG message print. */
 #define DBG_PRINT(dbg_level, args...)  if(!(debug_level<dbg_level)) printk(args)
 
+#ifndef DMA_ERROR_CODE
+#define DMA_ERROR_CODE          (~(dma_addr_t)0x0)
+#endif
+
 /* Protocol assist features of the NIC */
 #define L3_CKSUM_OK 0xFFFF
 #define L4_CKSUM_OK 0xFFFF
@@ -97,6 +101,7 @@ struct swStat {
         unsigned long long num_aggregations;
         /* Other statistics */
         unsigned long long mem_alloc_fail_cnt;
+        unsigned long long pci_map_fail_cnt;
         unsigned long long watchdog_timer_cnt;
         unsigned long long mem_allocated;
         unsigned long long mem_freed;