enic: Add support for 'ethtool -g/-G'

Add support for displaying and modifying rx and tx ring sizes using
ethtool.

Also, increasing version to  2.3.0.45
Signed-off-by: Parvi Kaustubhi <pkaustub@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cisco/enic/enic.h

@@ -33,7 +33,7 @@
 
 #define DRV_NAME		"enic"
 #define DRV_DESCRIPTION		"Cisco VIC Ethernet NIC Driver"
-#define DRV_VERSION		"2.3.0.42"
+#define DRV_VERSION		"2.3.0.45"
 #define DRV_COPYRIGHT		"Copyright 2008-2013 Cisco Systems, Inc"
 
 #define ENIC_BARS_MAX		6

drivers/net/ethernet/cisco/enic/enic_ethtool.c

@@ -176,6 +176,81 @@ static void enic_get_strings(struct net_device *netdev, u32 stringset,
 	}
 }
 
+static void enic_get_ringparam(struct net_device *netdev,
+			       struct ethtool_ringparam *ring)
+{
+	struct enic *enic = netdev_priv(netdev);
+	struct vnic_enet_config *c = &enic->config;
+
+	ring->rx_max_pending = ENIC_MAX_RQ_DESCS;
+	ring->rx_pending = c->rq_desc_count;
+	ring->tx_max_pending = ENIC_MAX_WQ_DESCS;
+	ring->tx_pending = c->wq_desc_count;
+}
+
+static int enic_set_ringparam(struct net_device *netdev,
+			      struct ethtool_ringparam *ring)
+{
+	struct enic *enic = netdev_priv(netdev);
+	struct vnic_enet_config *c = &enic->config;
+	int running = netif_running(netdev);
+	unsigned int rx_pending;
+	unsigned int tx_pending;
+	int err = 0;
+
+	if (ring->rx_mini_max_pending || ring->rx_mini_pending) {
+		netdev_info(netdev,
+			    "modifying mini ring params is not supported");
+		return -EINVAL;
+	}
+	if (ring->rx_jumbo_max_pending || ring->rx_jumbo_pending) {
+		netdev_info(netdev,
+			    "modifying jumbo ring params is not supported");
+		return -EINVAL;
+	}
+	rx_pending = c->rq_desc_count;
+	tx_pending = c->wq_desc_count;
+	if (ring->rx_pending > ENIC_MAX_RQ_DESCS ||
+	    ring->rx_pending < ENIC_MIN_RQ_DESCS) {
+		netdev_info(netdev, "rx pending (%u) not in range [%u,%u]",
+			    ring->rx_pending, ENIC_MIN_RQ_DESCS,
+			    ENIC_MAX_RQ_DESCS);
+		return -EINVAL;
+	}
+	if (ring->tx_pending > ENIC_MAX_WQ_DESCS ||
+	    ring->tx_pending < ENIC_MIN_WQ_DESCS) {
+		netdev_info(netdev, "tx pending (%u) not in range [%u,%u]",
+			    ring->tx_pending, ENIC_MIN_WQ_DESCS,
+			    ENIC_MAX_WQ_DESCS);
+		return -EINVAL;
+	}
+	if (running)
+		dev_close(netdev);
+	c->rq_desc_count =
+		ring->rx_pending & 0xffffffe0; /* must be aligned to groups of 32 */
+	c->wq_desc_count =
+		ring->tx_pending & 0xffffffe0; /* must be aligned to groups of 32 */
+	enic_free_vnic_resources(enic);
+	err = enic_alloc_vnic_resources(enic);
+	if (err) {
+		netdev_err(netdev,
+			   "Failed to alloc vNIC resources, aborting\n");
+		enic_free_vnic_resources(enic);
+		goto err_out;
+	}
+	enic_init_vnic_resources(enic);
+	if (running) {
+		err = dev_open(netdev);
+		if (err)
+			goto err_out;
+	}
+	return 0;
+err_out:
+	c->rq_desc_count = rx_pending;
+	c->wq_desc_count = tx_pending;
+	return err;
+}
+
 static int enic_get_sset_count(struct net_device *netdev, int sset)
 {
 	switch (sset) {
@@ -509,6 +584,8 @@ static const struct ethtool_ops enic_ethtool_ops = {
 	.set_msglevel = enic_set_msglevel,
 	.get_link = ethtool_op_get_link,
 	.get_strings = enic_get_strings,
+	.get_ringparam = enic_get_ringparam,
+	.set_ringparam = enic_set_ringparam,
 	.get_sset_count = enic_get_sset_count,
 	.get_ethtool_stats = enic_get_ethtool_stats,
 	.get_coalesce = enic_get_coalesce,