jme: Fix DMA unmap warning

The jme driver forgot to check the return status from pci_map_page in its tx
path, causing a dma api warning on unmap.  Easy fix, just do the check and
augment the tx path to tell the stack that the driver is busy so we re-queue the
frame.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Guo-Fu Tseng <cooldavid@cooldavid.org>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 6 deletions

diff --git a/drivers/net/ethernet/jme.c b/drivers/net/ethernet/jme.c
index b0c6050479eb..6e664d9038d6 100644
--- a/drivers/net/ethernet/jme.c
+++ b/drivers/net/ethernet/jme.c
@@ -1988,7 +1988,7 @@ jme_alloc_txdesc(struct jme_adapter *jme,
         return idx;
 }
 
-static void
+static int
 jme_fill_tx_map(struct pci_dev *pdev,
                 struct txdesc *txdesc,
                 struct jme_buffer_info *txbi,
@@ -2005,6 +2005,9 @@ jme_fill_tx_map(struct pci_dev *pdev,
                                 len,
                                 PCI_DMA_TODEVICE);
 
+        if (unlikely(pci_dma_mapping_error(pdev, dmaaddr)))
+                return -EINVAL;
+
         pci_dma_sync_single_for_device(pdev,
                                        dmaaddr,
                                        len,
@@ -2021,9 +2024,30 @@ jme_fill_tx_map(struct pci_dev *pdev,
 
         txbi->mapping = dmaaddr;
         txbi->len = len;
+        return 0;
 }
 
-static void
+static void jme_drop_tx_map(struct jme_adapter *jme, int startidx, int endidx)
+{
+        struct jme_ring *txring = &(jme->txring[0]);
+        struct jme_buffer_info *txbi = txring->bufinf, *ctxbi;
+        int mask = jme->tx_ring_mask;
+        int j;
+
+        for (j = startidx ; j < endidx ; ++j) {
+                ctxbi = txbi + ((startidx + j + 2) & (mask));
+                pci_unmap_page(jme->pdev,
+                                ctxbi->mapping,
+                                ctxbi->len,
+                                PCI_DMA_TODEVICE);
+
+                                ctxbi->mapping = 0;
+                                ctxbi->len = 0;
+        }
+
+}
+
+static int
 jme_map_tx_skb(struct jme_adapter *jme, struct sk_buff *skb, int idx)
 {
         struct jme_ring *txring = &(jme->txring[0]);
@@ -2034,25 +2058,37 @@ jme_map_tx_skb(struct jme_adapter *jme, struct sk_buff *skb, int idx)
         int mask = jme->tx_ring_mask;
         const struct skb_frag_struct *frag;
         u32 len;
+        int ret = 0;
 
         for (i = 0 ; i < nr_frags ; ++i) {
                 frag = &skb_shinfo(skb)->frags[i];
                 ctxdesc = txdesc + ((idx + i + 2) & (mask));
                 ctxbi = txbi + ((idx + i + 2) & (mask));
 
-                jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi,
+                ret = jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi,
                                 skb_frag_page(frag),
                                 frag->page_offset, skb_frag_size(frag), hidma);
+                if (ret) {
+                        jme_drop_tx_map(jme, idx, idx+i);
+                        goto out;
+                }
+
         }
 
         len = skb_is_nonlinear(skb) ? skb_headlen(skb) : skb->len;
         ctxdesc = txdesc + ((idx + 1) & (mask));
         ctxbi = txbi + ((idx + 1) & (mask));
-        jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi, virt_to_page(skb->data),
+        ret = jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi, virt_to_page(skb->data),
                         offset_in_page(skb->data), len, hidma);
+        if (ret)
+                jme_drop_tx_map(jme, idx, idx+i);
+
+out:
+        return ret;
 
 }
 
+
 static int
 jme_tx_tso(struct sk_buff *skb, __le16 *mss, u8 *flags)
 {
@@ -2131,6 +2167,7 @@ jme_fill_tx_desc(struct jme_adapter *jme, struct sk_buff *skb, int idx)
         struct txdesc *txdesc;
         struct jme_buffer_info *txbi;
         u8 flags;
+        int ret = 0;
 
         txdesc = (struct txdesc *)txring->desc + idx;
         txbi = txring->bufinf + idx;
@@ -2155,7 +2192,10 @@ jme_fill_tx_desc(struct jme_adapter *jme, struct sk_buff *skb, int idx)
         if (jme_tx_tso(skb, &txdesc->desc1.mss, &flags))
                 jme_tx_csum(jme, skb, &flags);
         jme_tx_vlan(skb, &txdesc->desc1.vlan, &flags);
-        jme_map_tx_skb(jme, skb, idx);
+        ret = jme_map_tx_skb(jme, skb, idx);
+        if (ret)
+                return ret;
+
         txdesc->desc1.flags = flags;
         /*
          * Set tx buffer info after telling NIC to send
@@ -2228,7 +2268,8 @@ jme_start_xmit(struct sk_buff *skb, struct net_device *netdev)
                 return NETDEV_TX_BUSY;
         }
 
-        jme_fill_tx_desc(jme, skb, idx);
+        if (jme_fill_tx_desc(jme, skb, idx))
+                return NETDEV_TX_BUSY;
 
         jwrite32(jme, JME_TXCS, jme->reg_txcs |
                                 TXCS_SELECT_QUEUE0 |