sfc: attach/detach EF100 representors along with their owning PF

Since representors piggy-back on the PF's queues for TX, they can
only accept new TXes while the PF is up. Thus, any operation which
detaches the PF must first detach all its VFreps.

Signed-off-by: Edward Cree <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/sfc/ef100_netdev.c

···
 	netif_dbg(efx, ifdown, efx->net_dev, "closing on CPU %d\n",
 		  raw_smp_processor_id());
 
+	efx_detach_reps(efx);
 	netif_stop_queue(net_dev);
 	efx_stop_all(efx);
 	efx_mcdi_mac_fini_stats(efx);
···
 	mutex_unlock(&efx->mac_lock);
 
 	efx->state = STATE_NET_UP;
+	if (netif_running(efx->net_dev))
+		efx_attach_reps(efx);
 
 	return 0;
 

drivers/net/ethernet/sfc/ef100_rep.c

···
 	spin_lock_bh(&efx->vf_reps_lock);
 	list_add_tail(&efv->list, &efx->vf_reps);
 	spin_unlock_bh(&efx->vf_reps_lock);
-	netif_carrier_off(net_dev);
-	netif_tx_stop_all_queues(net_dev);
+	if (netif_running(efx->net_dev) && efx->state == STATE_NET_UP) {
+		netif_device_attach(net_dev);
+		netif_carrier_on(net_dev);
+	} else {
+		netif_carrier_off(net_dev);
+		netif_tx_stop_all_queues(net_dev);
+	}
 	rtnl_unlock();
 
 	net_dev->netdev_ops = &efx_ef100_rep_netdev_ops;
···
 {
 	struct efx_nic *efx = efv->parent;
 
+	rtnl_lock();
 	spin_lock_bh(&efx->vf_reps_lock);
 	list_del(&efv->list);
 	spin_unlock_bh(&efx->vf_reps_lock);
+	rtnl_unlock();
 	free_netdev(efv->net_dev);
 }
 

drivers/net/ethernet/sfc/efx.h

···
 #include "net_driver.h"
 #include "ef100_rx.h"
 #include "ef100_tx.h"
+#include "efx_common.h"
 #include "filter.h"
 
 int efx_net_open(struct net_device *net_dev);
···
 {
 	struct net_device *dev = efx->net_dev;
 
+	/* We must stop reps (which use our TX) before we stop ourselves. */
+	efx_detach_reps(efx);
+
 	/* Lock/freeze all TX queues so that we can be sure the
 	 * TX scheduler is stopped when we're done and before
 	 * netif_device_present() becomes false.
···
 
 static inline void efx_device_attach_if_not_resetting(struct efx_nic *efx)
 {
-	if ((efx->state != STATE_DISABLED) && !efx->reset_pending)
+	if ((efx->state != STATE_DISABLED) && !efx->reset_pending) {
 		netif_device_attach(efx->net_dev);
+		if (efx->state == STATE_NET_UP)
+			efx_attach_reps(efx);
+	}
 }
 
 static inline bool efx_rwsem_assert_write_locked(struct rw_semaphore *sem)

drivers/net/ethernet/sfc/efx_common.c

···
 #include "mcdi_port_common.h"
 #include "io.h"
 #include "mcdi_pcol.h"
+#include "ef100_rep.h"
 
 static unsigned int debug = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
 			     NETIF_MSG_LINK | NETIF_MSG_IFDOWN |
···
 	if (snprintf(name, len, "p%u", efx->port_num) >= len)
 		return -EINVAL;
 	return 0;
+}
+
+void efx_detach_reps(struct efx_nic *efx)
+{
+	struct net_device *rep_dev;
+	struct efx_rep *efv;
+
+	ASSERT_RTNL();
+	netif_dbg(efx, drv, efx->net_dev, "Detaching VF representors\n");
+	list_for_each_entry(efv, &efx->vf_reps, list) {
+		rep_dev = efv->net_dev;
+		if (!rep_dev)
+			continue;
+		netif_carrier_off(rep_dev);
+		/* See efx_device_detach_sync() */
+		netif_tx_lock_bh(rep_dev);
+		netif_tx_stop_all_queues(rep_dev);
+		netif_tx_unlock_bh(rep_dev);
+	}
+}
+
+void efx_attach_reps(struct efx_nic *efx)
+{
+	struct net_device *rep_dev;
+	struct efx_rep *efv;
+
+	ASSERT_RTNL();
+	netif_dbg(efx, drv, efx->net_dev, "Attaching VF representors\n");
+	list_for_each_entry(efv, &efx->vf_reps, list) {
+		rep_dev = efv->net_dev;
+		if (!rep_dev)
+			continue;
+		netif_tx_wake_all_queues(rep_dev);
+		netif_carrier_on(rep_dev);
+	}
 }

drivers/net/ethernet/sfc/efx_common.h

···
 
 int efx_get_phys_port_name(struct net_device *net_dev,
 			   char *name, size_t len);
+
+void efx_detach_reps(struct efx_nic *efx);
+void efx_attach_reps(struct efx_nic *efx);
 #endif