S2io: Fix IOMMU overflow checking.

- Fix IOMMU overflow checking. As reported by Andi Kleen <ak@linux.intel.com>
removed check for zero dma address.

Signed-off-by: Santosh Rastapur <santosh.rastapur@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 22 insertions, 19 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 51a91154125d..685030bb1d5e 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -2501,6 +2501,9 @@ static void stop_nic(struct s2io_nic *nic)
 /**
  *  fill_rx_buffers - Allocates the Rx side skbs
  *  @ring_info: per ring structure
+ *  @from_card_up: If this is true, we will map the buffer to get
+ *     the dma address for buf0 and buf1 to give it to the card.
+ *     Else we will sync the already mapped buffer to give it to the card.
  *  Description:
  *  The function allocates Rx side skbs and puts the physical
  *  address of these buffers into the RxD buffer pointers, so that the NIC
@@ -2518,7 +2521,7 @@ static void stop_nic(struct s2io_nic *nic)
  *  SUCCESS on success or an appropriate -ve value on failure.
  */
 
-static int fill_rx_buffers(struct ring_info *ring)
+static int fill_rx_buffers(struct ring_info *ring, int from_card_up)
 {
         struct sk_buff *skb;
         struct RxD_t *rxdp;
@@ -2637,17 +2640,16 @@ static int fill_rx_buffers(struct ring_info *ring)
                         skb->data = (void *) (unsigned long)tmp;
                         skb_reset_tail_pointer(skb);
 
-                        /* AK: check is wrong. 0 can be valid dma address */
-                        if (!(rxdp3->Buffer0_ptr))
+                        if (from_card_up) {
                                 rxdp3->Buffer0_ptr =
                                    pci_map_single(ring->pdev, ba->ba_0,
                                         BUF0_LEN, PCI_DMA_FROMDEVICE);
-                        else
+                                if (pci_dma_mapping_error(rxdp3->Buffer0_ptr))
+                                        goto pci_map_failed;
+                        } else
                                 pci_dma_sync_single_for_device(ring->pdev,
                                 (dma_addr_t) rxdp3->Buffer0_ptr,
                                     BUF0_LEN, PCI_DMA_FROMDEVICE);
-                        if (pci_dma_mapping_error(rxdp3->Buffer0_ptr))
-                                goto pci_map_failed;
 
                         rxdp->Control_2 = SET_BUFFER0_SIZE_3(BUF0_LEN);
                         if (ring->rxd_mode == RXD_MODE_3B) {
@@ -2664,21 +2666,22 @@ static int fill_rx_buffers(struct ring_info *ring)
                                 if (pci_dma_mapping_error(rxdp3->Buffer2_ptr))
                                         goto pci_map_failed;
 
-                                /* AK: check is wrong */
-                                if (!rxdp3->Buffer1_ptr)
+                                if (from_card_up) {
                                         rxdp3->Buffer1_ptr =
                                                 pci_map_single(ring->pdev,
                                                 ba->ba_1, BUF1_LEN,
                                                 PCI_DMA_FROMDEVICE);
 
-                                if (pci_dma_mapping_error(rxdp3->Buffer1_ptr)) {
-                                        pci_unmap_single
-                                                (ring->pdev,
-                                                (dma_addr_t)(unsigned long)
-                                                skb->data,
-                                                ring->mtu + 4,
-                                                PCI_DMA_FROMDEVICE);
-                                        goto pci_map_failed;
+                                        if (pci_dma_mapping_error
+                                                (rxdp3->Buffer1_ptr)) {
+                                                pci_unmap_single
+                                                        (ring->pdev,
+                                                    (dma_addr_t)(unsigned long)
+                                                        skb->data,
+                                                        ring->mtu + 4,
+                                                        PCI_DMA_FROMDEVICE);
+                                                goto pci_map_failed;
+                                        }
                                 }
                                 rxdp->Control_2 |= SET_BUFFER1_SIZE_3(1);
                                 rxdp->Control_2 |= SET_BUFFER2_SIZE_3
@@ -2813,7 +2816,7 @@ static void free_rx_buffers(struct s2io_nic *sp)
 
 static int s2io_chk_rx_buffers(struct ring_info *ring)
 {
-        if (fill_rx_buffers(ring) == -ENOMEM) {
+        if (fill_rx_buffers(ring, 0) == -ENOMEM) {
                 DBG_PRINT(INFO_DBG, "%s:Out of memory", ring->dev->name);
                 DBG_PRINT(INFO_DBG, " in Rx Intr!!\n");
         }
@@ -2944,7 +2947,7 @@ static void s2io_netpoll(struct net_device *dev)
                 rx_intr_handler(&mac_control->rings[i], 0);
 
         for (i = 0; i < config->rx_ring_num; i++) {
-                if (fill_rx_buffers(&mac_control->rings[i]) == -ENOMEM) {
+                if (fill_rx_buffers(&mac_control->rings[i], 0) == -ENOMEM) {
                         DBG_PRINT(INFO_DBG, "%s:Out of memory", dev->name);
                         DBG_PRINT(INFO_DBG, " in Rx Netpoll!!\n");
                         break;
@@ -7183,7 +7186,7 @@ static int s2io_card_up(struct s2io_nic * sp)
 
         for (i = 0; i < config->rx_ring_num; i++) {
                 mac_control->rings[i].mtu = dev->mtu;
-                ret = fill_rx_buffers(&mac_control->rings[i]);
+                ret = fill_rx_buffers(&mac_control->rings[i], 1);
                 if (ret) {
                         DBG_PRINT(ERR_DBG, "%s: Out of memory in Open\n",
                                   dev->name);