fix ngbe, free iob after packet sent.

Change-Id: I70e826d8782b8697fdcbcec5dd04366021d185d6
Signed-off-by: Chong Qiao <qiaochong@loongson.cn>

sys/dev/pci/ngbe/ngbe_pmon_head.h

@@ -200,6 +200,7 @@ struct net_device
     int (*open)(struct net_device *ndev);
     int (*stop)(struct net_device *ndev);
     int (*hard_start_xmit)(struct sk_buff *skb, struct net_device *ndev);
+    struct io_buffer *iob_tx[EMERALD_NUM_TX_DESC];
 };
 
 #define alloc_etherdev(len) container_of(pci, struct net_device, pcidev)
@@ -246,12 +247,12 @@ int len;
 char *data;
 };
 
-int iob_len(struct io_buffer *iob)
+static int iob_len(struct io_buffer *iob)
 {
 return iob->len;
 }
 
-struct io_buffer *alloc_iob(int len)
+static struct io_buffer *alloc_iob(int len)
 {
     struct io_buffer *iobuf = malloc(sizeof(struct io_buffer), M_DEVBUF, M_DONTWAIT);
     iobuf->data = malloc(len, M_DEVBUF, M_DONTWAIT);
@@ -259,13 +260,13 @@ struct io_buffer *alloc_iob(int len)
     return iobuf;
 }
 
-int iob_put(struct io_buffer *iob, int len)
+static int iob_put(struct io_buffer *iob, int len)
 {
     iob->len = len;
     return 0;
 }
 
-int free_iob(struct io_buffer *iob)
+static int free_iob(struct io_buffer *iob)
 {
 	free(iob->data, M_DEVBUF);
 	free(iob,M_DEVBUF);
@@ -407,7 +408,9 @@ static void *malloc_dma(size_t size, size_t size1)
     buf = malloc(size, M_DEVBUF, M_DONTWAIT);
     return (void *)buf;
 }
-#define netdev_tx_complete_next(...)
+#define netdev_tx_complete_next(netdev) do { \
+	free_iob(netdev->iob_tx[tx_idx]); \
+} while(0)
 #define cpu_to_le64(x) (x)
 #define cpu_to_le16(x) (x)
 static inline netdev_link_up( struct net_device *netdev)

sys/dev/pci/ngbe/ngbe_pmon_tail.h

@@ -155,6 +155,11 @@ static void ngbe_start(struct ifnet *ifp)
         iob->len = mb_head->m_pkthdr.len;
 	if (emerald_transmit (sc, iob) < 0)
 	   free_iob(iob);
+	else {
+		struct emerald_nic *emerald = sc->priv;
+		int tx_idx = ( (emerald->tx.prod - 1) % EMERALD_NUM_TX_DESC );
+		sc->iob_tx[tx_idx] = iob;
+	}
 
         m_freem(mb_head);
     }