enic: check dma_mapping_error

This patch checks for pci_dma_mapping_error() after dma mapping the data.
If the dma mapping fails we remove the previously queued frags and return
NETDEV_TX_OK.

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 106 insertions, 58 deletions

diff --git a/drivers/net/ethernet/cisco/enic/enic.h b/drivers/net/ethernet/cisco/enic/enic.h
index 25c4d88853d8..b2ea35a3a881 100644
--- a/drivers/net/ethernet/cisco/enic/enic.h
+++ b/drivers/net/ethernet/cisco/enic/enic.h
@@ -242,6 +242,18 @@ static inline unsigned int enic_msix_notify_intr(struct enic *enic)
         return enic->rq_count + enic->wq_count + 1;
 }
 
+static inline int enic_dma_map_check(struct enic *enic, dma_addr_t dma_addr)
+{
+        if (unlikely(pci_dma_mapping_error(enic->pdev, dma_addr))) {
+                net_warn_ratelimited("%s: PCI dma mapping failed!\n",
+                                     enic->netdev->name);
+
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
 void enic_reset_addr_lists(struct enic *enic);
 int enic_sriov_enabled(struct enic *enic);
 int enic_is_valid_vf(struct enic *enic, int vf);
diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 705f334ebb85..142c9b5509ae 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -351,80 +351,94 @@ static irqreturn_t enic_isr_msix_notify(int irq, void *data)
         return IRQ_HANDLED;
 }
 
-static inline void enic_queue_wq_skb_cont(struct enic *enic,
-        struct vnic_wq *wq, struct sk_buff *skb,
-        unsigned int len_left, int loopback)
+static int enic_queue_wq_skb_cont(struct enic *enic, struct vnic_wq *wq,
+                                  struct sk_buff *skb, unsigned int len_left,
+                                  int loopback)
 {
         const skb_frag_t *frag;
+        dma_addr_t dma_addr;
 
         /* Queue additional data fragments */
         for (frag = skb_shinfo(skb)->frags; len_left; frag++) {
                 len_left -= skb_frag_size(frag);
-                enic_queue_wq_desc_cont(wq, skb,
-                        skb_frag_dma_map(&enic->pdev->dev,
-                                         frag, 0, skb_frag_size(frag),
-                                         DMA_TO_DEVICE),
-                        skb_frag_size(frag),
-                        (len_left == 0),        /* EOP? */
-                        loopback);
+                dma_addr = skb_frag_dma_map(&enic->pdev->dev, frag, 0,
+                                            skb_frag_size(frag),
+                                            DMA_TO_DEVICE);
+                if (unlikely(enic_dma_map_check(enic, dma_addr)))
+                        return -ENOMEM;
+                enic_queue_wq_desc_cont(wq, skb, dma_addr, skb_frag_size(frag),
+                                        (len_left == 0),        /* EOP? */
+                                        loopback);
         }
+
+        return 0;
 }
 
-static inline void enic_queue_wq_skb_vlan(struct enic *enic,
-        struct vnic_wq *wq, struct sk_buff *skb,
-        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
+static int enic_queue_wq_skb_vlan(struct enic *enic, struct vnic_wq *wq,
+                                  struct sk_buff *skb, int vlan_tag_insert,
+                                  unsigned int vlan_tag, int loopback)
 {
         unsigned int head_len = skb_headlen(skb);
         unsigned int len_left = skb->len - head_len;
         int eop = (len_left == 0);
+        dma_addr_t dma_addr;
+        int err = 0;
+
+        dma_addr = pci_map_single(enic->pdev, skb->data, head_len,
+                                  PCI_DMA_TODEVICE);
+        if (unlikely(enic_dma_map_check(enic, dma_addr)))
+                return -ENOMEM;
 
         /* Queue the main skb fragment. The fragments are no larger
          * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less
          * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor
          * per fragment is queued.
          */
-        enic_queue_wq_desc(wq, skb,
-                pci_map_single(enic->pdev, skb->data,
-                        head_len, PCI_DMA_TODEVICE),
-                head_len,
-                vlan_tag_insert, vlan_tag,
-                eop, loopback);
+        enic_queue_wq_desc(wq, skb, dma_addr, head_len, vlan_tag_insert,
+                           vlan_tag, eop, loopback);
 
         if (!eop)
-                enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
+                err = enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
+
+        return err;
 }
 
-static inline void enic_queue_wq_skb_csum_l4(struct enic *enic,
-        struct vnic_wq *wq, struct sk_buff *skb,
-        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
+static int enic_queue_wq_skb_csum_l4(struct enic *enic, struct vnic_wq *wq,
+                                     struct sk_buff *skb, int vlan_tag_insert,
+                                     unsigned int vlan_tag, int loopback)
 {
         unsigned int head_len = skb_headlen(skb);
         unsigned int len_left = skb->len - head_len;
         unsigned int hdr_len = skb_checksum_start_offset(skb);
         unsigned int csum_offset = hdr_len + skb->csum_offset;
         int eop = (len_left == 0);
+        dma_addr_t dma_addr;
+        int err = 0;
+
+        dma_addr = pci_map_single(enic->pdev, skb->data, head_len,
+                                  PCI_DMA_TODEVICE);
+        if (unlikely(enic_dma_map_check(enic, dma_addr)))
+                return -ENOMEM;
 
         /* Queue the main skb fragment. The fragments are no larger
          * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less
          * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor
          * per fragment is queued.
          */
-        enic_queue_wq_desc_csum_l4(wq, skb,
-                pci_map_single(enic->pdev, skb->data,
-                        head_len, PCI_DMA_TODEVICE),
-                head_len,
-                csum_offset,
-                hdr_len,
-                vlan_tag_insert, vlan_tag,
-                eop, loopback);
+        enic_queue_wq_desc_csum_l4(wq, skb, dma_addr, head_len, csum_offset,
+                                   hdr_len, vlan_tag_insert, vlan_tag, eop,
+                                   loopback);
 
         if (!eop)
-                enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
+                err = enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
+
+        return err;
 }
 
-static inline void enic_queue_wq_skb_tso(struct enic *enic,
-        struct vnic_wq *wq, struct sk_buff *skb, unsigned int mss,
-        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
+static int enic_queue_wq_skb_tso(struct enic *enic, struct vnic_wq *wq,
+                                 struct sk_buff *skb, unsigned int mss,
+                                 int vlan_tag_insert, unsigned int vlan_tag,
+                                 int loopback)
 {
         unsigned int frag_len_left = skb_headlen(skb);
         unsigned int len_left = skb->len - frag_len_left;
@@ -454,20 +468,19 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
          */
         while (frag_len_left) {
                 len = min(frag_len_left, (unsigned int)WQ_ENET_MAX_DESC_LEN);
-                dma_addr = pci_map_single(enic->pdev, skb->data + offset,
-                                len, PCI_DMA_TODEVICE);
-                enic_queue_wq_desc_tso(wq, skb,
-                        dma_addr,
-                        len,
-                        mss, hdr_len,
-                        vlan_tag_insert, vlan_tag,
-                        eop && (len == frag_len_left), loopback);
+                dma_addr = pci_map_single(enic->pdev, skb->data + offset, len,
+                                          PCI_DMA_TODEVICE);
+                if (unlikely(enic_dma_map_check(enic, dma_addr)))
+                        return -ENOMEM;
+                enic_queue_wq_desc_tso(wq, skb, dma_addr, len, mss, hdr_len,
+                                       vlan_tag_insert, vlan_tag,
+                                       eop && (len == frag_len_left), loopback);
                 frag_len_left -= len;
                 offset += len;
         }
 
         if (eop)
-                return;
+                return 0;
 
         /* Queue WQ_ENET_MAX_DESC_LEN length descriptors
          * for additional data fragments
@@ -483,16 +496,18 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
                         dma_addr = skb_frag_dma_map(&enic->pdev->dev, frag,
                                                     offset, len,
                                                     DMA_TO_DEVICE);
-                        enic_queue_wq_desc_cont(wq, skb,
-                                dma_addr,
-                                len,
-                                (len_left == 0) &&
-                                (len == frag_len_left),         /* EOP? */
-                                loopback);
+                        if (unlikely(enic_dma_map_check(enic, dma_addr)))
+                                return -ENOMEM;
+                        enic_queue_wq_desc_cont(wq, skb, dma_addr, len,
+                                                (len_left == 0) &&
+                                                 (len == frag_len_left),/*EOP*/
+                                                loopback);
                         frag_len_left -= len;
                         offset += len;
                 }
         }
+
+        return 0;
 }
 
 static inline void enic_queue_wq_skb(struct enic *enic,
@@ -502,6 +517,7 @@ static inline void enic_queue_wq_skb(struct enic *enic,
         unsigned int vlan_tag = 0;
         int vlan_tag_insert = 0;
         int loopback = 0;
+        int err;
 
         if (vlan_tx_tag_present(skb)) {
                 /* VLAN tag from trunking driver */
@@ -513,14 +529,30 @@ static inline void enic_queue_wq_skb(struct enic *enic,
         }
 
         if (mss)
-                enic_queue_wq_skb_tso(enic, wq, skb, mss,
-                        vlan_tag_insert, vlan_tag, loopback);
+                err = enic_queue_wq_skb_tso(enic, wq, skb, mss,
+                                            vlan_tag_insert, vlan_tag,
+                                            loopback);
         else if (skb->ip_summed == CHECKSUM_PARTIAL)
-                enic_queue_wq_skb_csum_l4(enic, wq, skb,
-                        vlan_tag_insert, vlan_tag, loopback);
+                err = enic_queue_wq_skb_csum_l4(enic, wq, skb, vlan_tag_insert,
+                                                vlan_tag, loopback);
         else
-                enic_queue_wq_skb_vlan(enic, wq, skb,
-                        vlan_tag_insert, vlan_tag, loopback);
+                err = enic_queue_wq_skb_vlan(enic, wq, skb, vlan_tag_insert,
+                                             vlan_tag, loopback);
+        if (unlikely(err)) {
+                struct vnic_wq_buf *buf;
+
+                buf = wq->to_use->prev;
+                /* while not EOP of previous pkt && queue not empty.
+                 * For all non EOP bufs, os_buf is NULL.
+                 */
+                while (!buf->os_buf && (buf->next != wq->to_clean)) {
+                        enic_free_wq_buf(wq, buf);
+                        wq->ring.desc_avail++;
+                        buf = buf->prev;
+                }
+                wq->to_use = buf->next;
+                dev_kfree_skb(skb);
+        }
 }
 
 /* netif_tx_lock held, process context with BHs disabled, or BH */
@@ -950,8 +982,12 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq)
         if (!skb)
                 return -ENOMEM;
 
-        dma_addr = pci_map_single(enic->pdev, skb->data,
-                len, PCI_DMA_FROMDEVICE);
+        dma_addr = pci_map_single(enic->pdev, skb->data, len,
+                                  PCI_DMA_FROMDEVICE);
+        if (unlikely(enic_dma_map_check(enic, dma_addr))) {
+                dev_kfree_skb(skb);
+                return -ENOMEM;
+        }
 
         enic_queue_rq_desc(rq, skb, os_buf_index,
                 dma_addr, len);