[SCSI] fcoe: fix fcoe in a DCB environment by adding DCB notifiers to set skb priority

Use DCB notifiers to set the skb priority to allow packets
to be steered and tagged correctly over DCB enabled drivers
that setup traffic classes.

This allows queue_mapping() routines to be removed in these
drivers that were previously inspecting the ethertype of
every skb to mark FCoE/FIP frames.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/fcoe/fcoe.c

@@ -31,6 +31,8 @@
 #include <linux/sysfs.h>
 #include <linux/ctype.h>
 #include <linux/workqueue.h>
+#include <net/dcbnl.h>
+#include <net/dcbevent.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsicam.h>
 #include <scsi/scsi_transport.h>
@@ -101,6 +103,8 @@ static int fcoe_ddp_done(struct fc_lport *, u16);
 static int fcoe_ddp_target(struct fc_lport *, u16, struct scatterlist *,
 			   unsigned int);
 static int fcoe_cpu_callback(struct notifier_block *, unsigned long, void *);
+static int fcoe_dcb_app_notification(struct notifier_block *notifier,
+				     ulong event, void *ptr);
 
 static bool fcoe_match(struct net_device *netdev);
 static int fcoe_create(struct net_device *netdev, enum fip_state fip_mode);
@@ -129,6 +133,11 @@ static struct notifier_block fcoe_cpu_notifier = {
 	.notifier_call = fcoe_cpu_callback,
 };
 
+/* notification function for DCB events */
+static struct notifier_block dcb_notifier = {
+	.notifier_call = fcoe_dcb_app_notification,
+};
+
 static struct scsi_transport_template *fcoe_nport_scsi_transport;
 static struct scsi_transport_template *fcoe_vport_scsi_transport;
 
@@ -1522,6 +1531,8 @@ int fcoe_xmit(struct fc_lport *lport, struct fc_frame *fp)
 	skb_reset_network_header(skb);
 	skb->mac_len = elen;
 	skb->protocol = htons(ETH_P_FCOE);
+	skb->priority = port->priority;
+
 	if (fcoe->netdev->priv_flags & IFF_802_1Q_VLAN &&
 	    fcoe->realdev->features & NETIF_F_HW_VLAN_TX) {
 		skb->vlan_tci = VLAN_TAG_PRESENT |
@@ -1747,6 +1758,7 @@ int fcoe_percpu_receive_thread(void *arg)
  */
 static void fcoe_dev_setup(void)
 {
+	register_dcbevent_notifier(&dcb_notifier);
 	register_netdevice_notifier(&fcoe_notifier);
 }
 
@@ -1755,9 +1767,69 @@ static void fcoe_dev_setup(void)
  */
 static void fcoe_dev_cleanup(void)
 {
+	unregister_dcbevent_notifier(&dcb_notifier);
 	unregister_netdevice_notifier(&fcoe_notifier);
 }
 
+static struct fcoe_interface *
+fcoe_hostlist_lookup_realdev_port(struct net_device *netdev)
+{
+	struct fcoe_interface *fcoe;
+	struct net_device *real_dev;
+
+	list_for_each_entry(fcoe, &fcoe_hostlist, list) {
+		if (fcoe->netdev->priv_flags & IFF_802_1Q_VLAN)
+			real_dev = vlan_dev_real_dev(fcoe->netdev);
+		else
+			real_dev = fcoe->netdev;
+
+		if (netdev == real_dev)
+			return fcoe;
+	}
+	return NULL;
+}
+
+static int fcoe_dcb_app_notification(struct notifier_block *notifier,
+				     ulong event, void *ptr)
+{
+	struct dcb_app_type *entry = ptr;
+	struct fcoe_interface *fcoe;
+	struct net_device *netdev;
+	struct fcoe_port *port;
+	int prio;
+
+	if (entry->app.selector != DCB_APP_IDTYPE_ETHTYPE)
+		return NOTIFY_OK;
+
+	netdev = dev_get_by_index(&init_net, entry->ifindex);
+	if (!netdev)
+		return NOTIFY_OK;
+
+	fcoe = fcoe_hostlist_lookup_realdev_port(netdev);
+	dev_put(netdev);
+	if (!fcoe)
+		return NOTIFY_OK;
+
+	if (entry->dcbx & DCB_CAP_DCBX_VER_CEE)
+		prio = ffs(entry->app.priority) - 1;
+	else
+		prio = entry->app.priority;
+
+	if (prio < 0)
+		return NOTIFY_OK;
+
+	if (entry->app.protocol == ETH_P_FIP ||
+	    entry->app.protocol == ETH_P_FCOE)
+		fcoe->ctlr.priority = prio;
+
+	if (entry->app.protocol == ETH_P_FCOE) {
+		port = lport_priv(fcoe->ctlr.lp);
+		port->priority = prio;
+	}
+
+	return NOTIFY_OK;
+}
+
 /**
  * fcoe_device_notification() - Handler for net device events
  * @notifier: The context of the notification
@@ -1965,6 +2037,46 @@ static bool fcoe_match(struct net_device *netdev)
 	return true;
 }
 
+/**
+ * fcoe_dcb_create() - Initialize DCB attributes and hooks
+ * @netdev: The net_device object of the L2 link that should be queried
+ * @port: The fcoe_port to bind FCoE APP priority with
+ * @
+ */
+static void fcoe_dcb_create(struct fcoe_interface *fcoe)
+{
+#ifdef CONFIG_DCB
+	int dcbx;
+	u8 fup, up;
+	struct net_device *netdev = fcoe->realdev;
+	struct fcoe_port *port = lport_priv(fcoe->ctlr.lp);
+	struct dcb_app app = {
+				.priority = 0,
+				.protocol = ETH_P_FCOE
+			     };
+
+	/* setup DCB priority attributes. */
+	if (netdev && netdev->dcbnl_ops && netdev->dcbnl_ops->getdcbx) {
+		dcbx = netdev->dcbnl_ops->getdcbx(netdev);
+
+		if (dcbx & DCB_CAP_DCBX_VER_IEEE) {
+			app.selector = IEEE_8021QAZ_APP_SEL_ETHERTYPE;
+			up = dcb_ieee_getapp_mask(netdev, &app);
+			app.protocol = ETH_P_FIP;
+			fup = dcb_ieee_getapp_mask(netdev, &app);
+		} else {
+			app.selector = DCB_APP_IDTYPE_ETHTYPE;
+			up = dcb_getapp(netdev, &app);
+			app.protocol = ETH_P_FIP;
+			fup = dcb_getapp(netdev, &app);
+		}
+
+		port->priority = ffs(up) ? ffs(up) - 1 : 0;
+		fcoe->ctlr.priority = ffs(fup) ? ffs(fup) - 1 : port->priority;
+	}
+#endif
+}
+
 /**
  * fcoe_create() - Create a fcoe interface
  * @netdev  : The net_device object the Ethernet interface to create on
@@ -2008,6 +2120,9 @@ static int fcoe_create(struct net_device *netdev, enum fip_state fip_mode)
 	/* Make this the "master" N_Port */
 	fcoe->ctlr.lp = lport;
 
+	/* setup DCB priority attributes. */
+	fcoe_dcb_create(fcoe);
+
 	/* add to lports list */
 	fcoe_hostlist_add(lport);
 

drivers/scsi/fcoe/fcoe_ctlr.c

@@ -320,6 +320,7 @@ static void fcoe_ctlr_solicit(struct fcoe_ctlr *fip, struct fcoe_fcf *fcf)
 
 	skb_put(skb, sizeof(*sol));
 	skb->protocol = htons(ETH_P_FIP);
+	skb->priority = fip->priority;
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 	fip->send(fip, skb);
@@ -474,6 +475,7 @@ static void fcoe_ctlr_send_keep_alive(struct fcoe_ctlr *fip,
 	}
 	skb_put(skb, len);
 	skb->protocol = htons(ETH_P_FIP);
+	skb->priority = fip->priority;
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 	fip->send(fip, skb);
@@ -566,6 +568,7 @@ static int fcoe_ctlr_encaps(struct fcoe_ctlr *fip, struct fc_lport *lport,
 	cap->fip.fip_dl_len = htons(dlen / FIP_BPW);
 
 	skb->protocol = htons(ETH_P_FIP);
+	skb->priority = fip->priority;
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 	return 0;
@@ -1911,6 +1914,7 @@ static void fcoe_ctlr_vn_send(struct fcoe_ctlr *fip,
 
 	skb_put(skb, len);
 	skb->protocol = htons(ETH_P_FIP);
+	skb->priority = fip->priority;
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
 

include/scsi/libfcoe.h

@@ -147,6 +147,7 @@ struct fcoe_ctlr {
 	u8 map_dest;
 	u8 spma;
 	u8 probe_tries;
+	u8 priority;
 	u8 dest_addr[ETH_ALEN];
 	u8 ctl_src_addr[ETH_ALEN];
 
@@ -301,6 +302,7 @@ struct fcoe_percpu_s {
  * @lport:		       The associated local port
  * @fcoe_pending_queue:	       The pending Rx queue of skbs
  * @fcoe_pending_queue_active: Indicates if the pending queue is active
+ * @priority:		       Packet priority (DCB)
  * @max_queue_depth:	       Max queue depth of pending queue
  * @min_queue_depth:	       Min queue depth of pending queue
  * @timer:		       The queue timer
@@ -316,6 +318,7 @@ struct fcoe_port {
 	struct fc_lport	      *lport;
 	struct sk_buff_head   fcoe_pending_queue;
 	u8		      fcoe_pending_queue_active;
+	u8		      priority;
 	u32		      max_queue_depth;
 	u32		      min_queue_depth;
 	struct timer_list     timer;