ucc_geth: Add support for skb recycling

We can reclaim transmitted skbs to use in the receive path, so-called
skb recycling support.

Also reorder ucc_geth_poll() steps, so that we'll clean tx ring firstly,
thus maybe reclaim some skbs for rx.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
index 5ba9586..ca476a5 100644 (file)
--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -209,9 +209,10 @@ static struct sk_buff *get_new_skb(struct ucc_geth_private *ugeth,
 {
        struct sk_buff *skb = NULL;
 
-       skb = dev_alloc_skb(ugeth->ug_info->uf_info.max_rx_buf_length +
-                                 UCC_GETH_RX_DATA_BUF_ALIGNMENT);
-
+       skb = __skb_dequeue(&ugeth->rx_recycle);
+       if (!skb)
+               skb = dev_alloc_skb(ugeth->ug_info->uf_info.max_rx_buf_length +
+                                   UCC_GETH_RX_DATA_BUF_ALIGNMENT);
        if (skb == NULL)
                return NULL;
 
@@ -1986,6 +1987,8 @@ static void ucc_geth_memclean(struct ucc_geth_private *ugeth)
                iounmap(ugeth->ug_regs);
                ugeth->ug_regs = NULL;
        }
+
+       skb_queue_purge(&ugeth->rx_recycle);
 }
 
 static void ucc_geth_set_multi(struct net_device *dev)
@@ -2202,6 +2205,8 @@ static int ucc_struct_init(struct ucc_geth_private *ugeth)
                return -ENOMEM;
        }
 
+       skb_queue_head_init(&ugeth->rx_recycle);
+
        return 0;
 }
 
@@ -3208,8 +3213,10 @@ static int ucc_geth_rx(struct ucc_geth_private *ugeth, u8 rxQ, int rx_work_limit
                        if (netif_msg_rx_err(ugeth))
                                ugeth_err("%s, %d: ERROR!!! skb - 0x%08x",
                                           __func__, __LINE__, (u32) skb);
-                       if (skb)
-                               dev_kfree_skb_any(skb);
+                       if (skb) {
+                               skb->data = skb->head + NET_SKB_PAD;
+                               __skb_queue_head(&ugeth->rx_recycle, skb);
+                       }
 
                        ugeth->rx_skbuff[rxQ][ugeth->skb_currx[rxQ]] = NULL;
                        dev->stats.rx_dropped++;
@@ -3267,6 +3274,8 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ)
 
        /* Normal processing. */
        while ((bd_status & T_R) == 0) {
+               struct sk_buff *skb;
+
                /* BD contains already transmitted buffer.   */
                /* Handle the transmitted buffer and release */
                /* the BD to be used with the current frame  */
@@ -3276,9 +3285,16 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ)
 
                dev->stats.tx_packets++;
 
-               /* Free the sk buffer associated with this TxBD */
-               dev_kfree_skb(ugeth->
-                                 tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]);
+               skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]];
+
+               if (skb_queue_len(&ugeth->rx_recycle) < RX_BD_RING_LEN &&
+                            skb_recycle_check(skb,
+                                   ugeth->ug_info->uf_info.max_rx_buf_length +
+                                   UCC_GETH_RX_DATA_BUF_ALIGNMENT))
+                       __skb_queue_head(&ugeth->rx_recycle, skb);
+               else
+                       dev_kfree_skb(skb);
+
                ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]] = NULL;
                ugeth->skb_dirtytx[txQ] =
                    (ugeth->skb_dirtytx[txQ] +
@@ -3307,16 +3323,16 @@ static int ucc_geth_poll(struct napi_struct *napi, int budget)
 
        ug_info = ugeth->ug_info;
 
-       howmany = 0;
-       for (i = 0; i < ug_info->numQueuesRx; i++)
-               howmany += ucc_geth_rx(ugeth, i, budget - howmany);
-
        /* Tx event processing */
        spin_lock(&ugeth->lock);
        for (i = 0; i < ug_info->numQueuesTx; i++)
                ucc_geth_tx(ugeth->ndev, i);
        spin_unlock(&ugeth->lock);
 
+       howmany = 0;
+       for (i = 0; i < ug_info->numQueuesRx; i++)
+               howmany += ucc_geth_rx(ugeth, i, budget - howmany);
+
        if (howmany < budget) {
                napi_complete(napi);
                setbits32(ugeth->uccf->p_uccm, UCCE_RX_EVENTS | UCCE_TX_EVENTS);

diff --git a/drivers/net/ucc_geth.h b/drivers/net/ucc_geth.h
index 195ab26..cfb31af 100644 (file)
--- a/drivers/net/ucc_geth.h
+++ b/drivers/net/ucc_geth.h
@@ -1212,6 +1212,8 @@ struct ucc_geth_private {
        /* index of the first skb which hasn't been transmitted yet. */
        u16 skb_dirtytx[NUM_TX_QUEUES];
 
+       struct sk_buff_head rx_recycle;
+
        struct ugeth_mii_info *mii_info;
        struct phy_device *phydev;
        phy_interface_t phy_interface;