gianfar: Add backwards compatible Single Queue mode polling

Older Single Queue (SQ_SG_MODE) devices like TSEC (i.e. mpc83xx)
don't feature the frame receive indication bits (RXF) in RSTAT.
For these and for the rest of the SQ_SG_MODE devices, provide the
appropiate polling routine that handles a single pair of Rx/Tx
BD rings, removing the overhead incurred by the multiple queues/
multiple interrupt group devices (veTSEC/ eTSEC2.0 devices).
So this is primarily a fix for the TSEC devices.

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 14f0694..8d2db7b 100644 (file)
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -128,6 +128,7 @@ static void gfar_set_multi(struct net_device *dev);
 static void gfar_set_hash_for_addr(struct net_device *dev, u8 *addr);
 static void gfar_configure_serdes(struct net_device *dev);
 static int gfar_poll(struct napi_struct *napi, int budget);
+static int gfar_poll_sq(struct napi_struct *napi, int budget);
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void gfar_netpoll(struct net_device *dev);
 #endif
@@ -1038,9 +1039,13 @@ static int gfar_probe(struct platform_device *ofdev)
        dev->ethtool_ops = &gfar_ethtool_ops;
 
        /* Register for napi ...We are registering NAPI for each grp */
-       for (i = 0; i < priv->num_grps; i++)
-               netif_napi_add(dev, &priv->gfargrp[i].napi, gfar_poll,
+       if (priv->mode == SQ_SG_MODE)
+               netif_napi_add(dev, &priv->gfargrp[0].napi, gfar_poll_sq,
                               GFAR_DEV_WEIGHT);
+       else
+               for (i = 0; i < priv->num_grps; i++)
+                       netif_napi_add(dev, &priv->gfargrp[i].napi, gfar_poll,
+                                      GFAR_DEV_WEIGHT);
 
        if (priv->device_flags & FSL_GIANFAR_DEV_HAS_CSUM) {
                dev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG |
@@ -2823,6 +2828,48 @@ int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit)
        return howmany;
 }
 
+static int gfar_poll_sq(struct napi_struct *napi, int budget)
+{
+       struct gfar_priv_grp *gfargrp =
+               container_of(napi, struct gfar_priv_grp, napi);
+       struct gfar __iomem *regs = gfargrp->regs;
+       struct gfar_priv_tx_q *tx_queue = gfargrp->priv->tx_queue[0];
+       struct gfar_priv_rx_q *rx_queue = gfargrp->priv->rx_queue[0];
+       int work_done = 0;
+
+       /* Clear IEVENT, so interrupts aren't called again
+        * because of the packets that have already arrived
+        */
+       gfar_write(&regs->ievent, IEVENT_RTX_MASK);
+
+       /* run Tx cleanup to completion */
+       if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx])
+               gfar_clean_tx_ring(tx_queue);
+
+       work_done = gfar_clean_rx_ring(rx_queue, budget);
+
+       if (work_done < budget) {
+               napi_complete(napi);
+               /* Clear the halt bit in RSTAT */
+               gfar_write(&regs->rstat, gfargrp->rstat);
+
+               gfar_write(&regs->imask, IMASK_DEFAULT);
+
+               /* If we are coalescing interrupts, update the timer
+                * Otherwise, clear it
+                */
+               gfar_write(&regs->txic, 0);
+               if (likely(tx_queue->txcoalescing))
+                       gfar_write(&regs->txic, tx_queue->txic);
+
+               gfar_write(&regs->rxic, 0);
+               if (unlikely(rx_queue->rxcoalescing))
+                       gfar_write(&regs->rxic, rx_queue->rxic);
+       }
+
+       return work_done;
+}
+
 static int gfar_poll(struct napi_struct *napi, int budget)
 {
        struct gfar_priv_grp *gfargrp =