From: Doug Ledford <dledford@redhat.com>
Date: Wed, 24 Feb 2010 19:32:14 -0500
Subject: [net] mlx4: pass eth attributes down to vlan interfaces
Message-id: <4B857EBE.9040703@redhat.com>
Patchwork-id: 23422
O-Subject: [Patch RHEL5.5] net: pass eth attributes down to vlan interfaces
Bugzilla: 557109
RH-Acked-by: Andy Gospodarek <gospo@redhat.com>
RH-Acked-by: David S. Miller <davem@redhat.com>

There are a few ethernet interface options that, when passed down to
vlan child interfaces, greatly effect vlan performance.  This patch adds
a couple flags to the capability bits for eth interfaces and then for
the mlx4 interface passes them on down.  I hear there are other eth
cards that would support this too, but I don't deal with this and made
no attempt to modify their setups.

I should note that this patch was originally very kABI problematic.  The
version here is as unproblematic as we could make it, but it still makes
use of bits that used to be masked off and reserved.  For the most part,
driver authors are smart enough not to use reserved bits for their own
purposes, but if there are any drivers out there that *did* do so, this
could be a problem for them.  However, this was deemed by Andy to be a
"not very likely and not much to worry about" event.  I tend to agree.

Resolves bz557109, and is currently being reviewed for acks.  If it
doesn't get approved for rhel5.5, then I'll repost for 5.6.

Signed-off-by: Jarod Wilson <jarod@redhat.com>

diff --git a/drivers/net/mlx4/en_netdev.c b/drivers/net/mlx4/en_netdev.c
index cfee71f..6c554cf 100644
--- a/drivers/net/mlx4/en_netdev.c
+++ b/drivers/net/mlx4/en_netdev.c
@@ -1077,6 +1077,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	 */
 	dev->features |= NETIF_F_SG;
 	dev->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+	dev->features |= NETIF_F_VLAN_CSUM;
 	dev->features |= NETIF_F_HIGHDMA;
 	dev->features |= NETIF_F_HW_VLAN_TX |
 			 NETIF_F_HW_VLAN_RX |
@@ -1086,6 +1087,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	if (mdev->LSO_support) {
 		dev->features |= NETIF_F_TSO;
 		dev->features |= NETIF_F_TSO6;
+		dev->features |= NETIF_F_VLAN_TSO;
 	}
 
 	dev->tx_queue_len = 100;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c2f9726..41d52e4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -348,9 +348,15 @@ struct net_device
 #define NETIF_F_LLTX		4096	/* LockLess TX */
 #define NETIF_F_GRO		16384	/* Generic receive offload */
 
+/* Go to the end of the bit field and count backwards when adding new entries
+ * so we don't cause the calculated fields below to shift.  Also don't forget
+ * to update GSO_MASK below to exclude added bits */
+#define NETIF_F_VLAN_TSO	1 << 31	/* Supports TSO for VLANs */
+#define NETIF_F_VLAN_CSUM	1 << 30	/* Supports TX checksumming for VLANs */
+
 	/* Segmentation offload features */
 #define NETIF_F_GSO_SHIFT	16
-#define NETIF_F_GSO_MASK	0xffff0000
+#define NETIF_F_GSO_MASK	0x3fff0000
 #define NETIF_F_TSO		(SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT)
 #define NETIF_F_UFO		(SKB_GSO_UDP << NETIF_F_GSO_SHIFT)
 #define NETIF_F_GSO_ROBUST	(SKB_GSO_DODGY << NETIF_F_GSO_SHIFT)
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 0ade055..b6c9f6c 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
+#include <linux/ethtool.h>
 #include <net/datalink.h>
 #include <linux/mm.h>
 #include <linux/in.h>
@@ -318,10 +319,26 @@ static int unregister_vlan_device(const char *vlan_IF_name)
 	return ret;
 }
 
+static u32 vlan_ethtool_get_rx_csum(struct net_device *dev)
+{
+	const struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
+	struct net_device *real_dev = vlan->real_dev;
+
+	if (real_dev->ethtool_ops == NULL ||
+	    real_dev->ethtool_ops->get_rx_csum == NULL)
+		return 0;
+	return real_dev->ethtool_ops->get_rx_csum(real_dev);
+}
+
+static const struct ethtool_ops vlan_ethtool_ops = {
+	.get_link		= ethtool_op_get_link,
+	.get_rx_csum		= vlan_ethtool_get_rx_csum,
+};
+
 static void vlan_setup(struct net_device *new_dev)
 {
 	SET_MODULE_OWNER(new_dev);
-	    
+
 	/* new_dev->ifindex = 0;  it will be set when added to
 	 * the global list.
 	 * iflink is set as well.
@@ -344,6 +361,7 @@ static void vlan_setup(struct net_device *new_dev)
 	new_dev->set_multicast_list = vlan_dev_set_multicast_list;
 	new_dev->destructor = free_netdev;
 	new_dev->do_ioctl = vlan_dev_ioctl;
+	new_dev->ethtool_ops = &vlan_ethtool_ops;
 }
 
 static void vlan_transfer_operstate(const struct net_device *dev, struct net_device *vlandev)
@@ -483,6 +501,11 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
 					     (1<<__LINK_STATE_DORMANT))) |
 			 (1<<__LINK_STATE_PRESENT); 
 
+	if (real_dev->features & NETIF_F_VLAN_TSO)
+		new_dev->features |= real_dev->features & VLAN_TSO_FEATURES;
+	if (real_dev->features & NETIF_F_VLAN_CSUM)
+		new_dev->features |= real_dev->features & NETIF_F_ALL_CSUM;
+
 	/* need 4 bytes for extra VLAN header info,
 	 * hope the underlying device can handle it.
 	 */
@@ -592,6 +615,24 @@ out_ret_null:
 	return NULL;
 }
 
+static void vlan_transfer_features(struct net_device *dev,
+				   struct net_device *vlandev)
+{
+	unsigned long old_features = vlandev->features;
+
+	if (dev->features & NETIF_F_VLAN_TSO) {
+		vlandev->features &= ~VLAN_TSO_FEATURES;
+		vlandev->features |= dev->features & VLAN_TSO_FEATURES;
+	}
+	if (dev->features & NETIF_F_VLAN_CSUM) {
+		vlandev->features &= ~NETIF_F_ALL_CSUM;
+		vlandev->features |= dev->features & NETIF_F_ALL_CSUM;
+	}
+
+	if (old_features != vlandev->features)
+		netdev_features_change(vlandev);
+}
+
 static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
 {
 	struct net_device *dev = ptr;
@@ -618,6 +659,18 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 		}
 		break;
 
+	case NETDEV_FEAT_CHANGE:
+		/* Propagate device features to underlying device */
+		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
+			vlandev = grp->vlan_devices[i];
+			if (!vlandev)
+				continue;
+
+			vlan_transfer_features(dev, vlandev);
+		}
+
+		break;
+
 	case NETDEV_DOWN:
 		/* Put all VLANs for this dev in the down state too.  */
 		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 9ae3a14..4ef1fbe 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -34,6 +34,8 @@ extern unsigned short vlan_name_type;
 #define VLAN_GRP_HASH_SIZE	(1 << VLAN_GRP_HASH_SHIFT)
 #define VLAN_GRP_HASH_MASK	(VLAN_GRP_HASH_SIZE - 1)
 
+#define VLAN_TSO_FEATURES	(NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_SG)
+
 /*  Find a VLAN device by the MAC address of its Ethernet device, and
  *  it's VLAN ID.  The default configuration is to have VLAN's scope
  *  to be box-wide, so the MAC will be ignored.  The mac will only be