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Commit 84a3f4db authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
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net/mvneta: Convert to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: netdev@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160818125731.27256-9-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent c4544dbc

drivers/net/ethernet/marvell/mvneta.c

+143 −89
Original line number Original line Diff line number Diff line
@@ -382,7 +382,8 @@ struct mvneta_port { 
	struct mvneta_rx_queue *rxqs;

	struct mvneta_rx_queue *rxqs;

	struct mvneta_tx_queue *txqs;

	struct mvneta_tx_queue *txqs;

	struct net_device *dev;

	struct net_device *dev;

	struct notifier_block cpu_notifier;

	struct hlist_node node_online;

	struct hlist_node node_dead;

	int rxq_def;

	int rxq_def;

	/* Protect the access to the percpu interrupt registers,

	/* Protect the access to the percpu interrupt registers,

	 * ensuring that the configuration remains coherent.

	 * ensuring that the configuration remains coherent.
@@ -574,6 +575,7 @@ struct mvneta_rx_queue { 
	int next_desc_to_proc;

	int next_desc_to_proc;

};

};





static enum cpuhp_state online_hpstate;

/* The hardware supports eight (8) rx queues, but we are only allowing

/* The hardware supports eight (8) rx queues, but we are only allowing

 * the first one to be used. Therefore, let's just allocate one queue.

 * the first one to be used. Therefore, let's just allocate one queue.

 */

 */
@@ -3311,31 +3313,28 @@ static void mvneta_percpu_elect(struct mvneta_port *pp) 
	}

	}

};

};





static int mvneta_percpu_notifier(struct notifier_block *nfb,

static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)

				  unsigned long action, void *hcpu)

{

{

	struct mvneta_port *pp = container_of(nfb, struct mvneta_port,

	int other_cpu;

					      cpu_notifier);

	struct mvneta_port *pp = hlist_entry_safe(node, struct mvneta_port,

	int cpu = (unsigned long)hcpu, other_cpu;

						  node_online);

	struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);

	struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);





	switch (action) {



	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

	case CPU_DOWN_FAILED:

	case CPU_DOWN_FAILED_FROZEN:

	spin_lock(&pp->lock);

	spin_lock(&pp->lock);

		/* Configuring the driver for a new CPU while the

	/*

		 * driver is stopping is racy, so just avoid it.

	 * Configuring the driver for a new CPU while the driver is

	 * stopping is racy, so just avoid it.

	 */

	 */

	if (pp->is_stopped) {

	if (pp->is_stopped) {

		spin_unlock(&pp->lock);

		spin_unlock(&pp->lock);

			break;

		return 0;

	}

	}

	netif_tx_stop_all_queues(pp->dev);

	netif_tx_stop_all_queues(pp->dev);





		/* We have to synchronise on tha napi of each CPU

	/*

		 * except the one just being waked up

	 * We have to synchronise on tha napi of each CPU except the one

	 * just being woken up

	 */

	 */

	for_each_online_cpu(other_cpu) {

	for_each_online_cpu(other_cpu) {

		if (other_cpu != cpu) {

		if (other_cpu != cpu) {
@@ -3350,13 +3349,14 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb, 
	on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);

	on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);

	napi_enable(&port->napi);

	napi_enable(&port->napi);







	/*

		/* Enable per-CPU interrupts on the CPU that is

	 * Enable per-CPU interrupts on the CPU that is

	 * brought up.

	 * brought up.

	 */

	 */

	mvneta_percpu_enable(pp);

	mvneta_percpu_enable(pp);





		/* Enable per-CPU interrupt on the one CPU we care

	/*

	 * Enable per-CPU interrupt on the one CPU we care

	 * about.

	 * about.

	 */

	 */

	mvneta_percpu_elect(pp);

	mvneta_percpu_elect(pp);
@@ -3369,12 +3369,18 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb, 
		    MVNETA_CAUSE_PSC_SYNC_CHANGE);

		    MVNETA_CAUSE_PSC_SYNC_CHANGE);

	netif_tx_start_all_queues(pp->dev);

	netif_tx_start_all_queues(pp->dev);

	spin_unlock(&pp->lock);

	spin_unlock(&pp->lock);

		break;

	return 0;

	case CPU_DOWN_PREPARE:

}

	case CPU_DOWN_PREPARE_FROZEN:



		netif_tx_stop_all_queues(pp->dev);

static int mvneta_cpu_down_prepare(unsigned int cpu, struct hlist_node *node)

		/* Thanks to this lock we are sure that any pending

{

		 * cpu election is done

	struct mvneta_port *pp = hlist_entry_safe(node, struct mvneta_port,

						  node_online);

	struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);



	/*

	 * Thanks to this lock we are sure that any pending cpu election is

	 * done.

	 */

	 */

	spin_lock(&pp->lock);

	spin_lock(&pp->lock);

	/* Mask all ethernet port interrupts */

	/* Mask all ethernet port interrupts */
@@ -3383,14 +3389,16 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb, 




	napi_synchronize(&port->napi);

	napi_synchronize(&port->napi);

	napi_disable(&port->napi);

	napi_disable(&port->napi);

		/* Disable per-CPU interrupts on the CPU that is

	/* Disable per-CPU interrupts on the CPU that is brought down. */

		 * brought down.

		 */

	mvneta_percpu_disable(pp);

	mvneta_percpu_disable(pp);

	return 0;

}



static int mvneta_cpu_dead(unsigned int cpu, struct hlist_node *node)

{

	struct mvneta_port *pp = hlist_entry_safe(node, struct mvneta_port,

						  node_dead);





		break;

	case CPU_DEAD:

	case CPU_DEAD_FROZEN:

	/* Check if a new CPU must be elected now this on is down */

	/* Check if a new CPU must be elected now this on is down */

	spin_lock(&pp->lock);

	spin_lock(&pp->lock);

	mvneta_percpu_elect(pp);

	mvneta_percpu_elect(pp);
@@ -3402,10 +3410,7 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb, 
		    MVNETA_CAUSE_LINK_CHANGE |

		    MVNETA_CAUSE_LINK_CHANGE |

		    MVNETA_CAUSE_PSC_SYNC_CHANGE);

		    MVNETA_CAUSE_PSC_SYNC_CHANGE);

	netif_tx_start_all_queues(pp->dev);

	netif_tx_start_all_queues(pp->dev);

		break;

	return 0;

	}



	return NOTIFY_OK;

}

}





static int mvneta_open(struct net_device *dev)

static int mvneta_open(struct net_device *dev)
@@ -3442,7 +3447,15 @@ static int mvneta_open(struct net_device *dev) 
	/* Register a CPU notifier to handle the case where our CPU

	/* Register a CPU notifier to handle the case where our CPU

	 * might be taken offline.

	 * might be taken offline.

	 */

	 */

	register_cpu_notifier(&pp->cpu_notifier);

	ret = cpuhp_state_add_instance_nocalls(online_hpstate,

					       &pp->node_online);

	if (ret)

		goto err_free_irq;



	ret = cpuhp_state_add_instance_nocalls(CPUHP_NET_MVNETA_DEAD,

					       &pp->node_dead);

	if (ret)

		goto err_free_online_hp;





	/* In default link is down */

	/* In default link is down */

	netif_carrier_off(pp->dev);

	netif_carrier_off(pp->dev);
@@ -3450,15 +3463,19 @@ static int mvneta_open(struct net_device *dev) 
	ret = mvneta_mdio_probe(pp);

	ret = mvneta_mdio_probe(pp);

	if (ret < 0) {

	if (ret < 0) {

		netdev_err(dev, "cannot probe MDIO bus\n");

		netdev_err(dev, "cannot probe MDIO bus\n");

		goto err_free_irq;

		goto err_free_dead_hp;

	}

	}





	mvneta_start_dev(pp);

	mvneta_start_dev(pp);





	return 0;

	return 0;





err_free_dead_hp:

	cpuhp_state_remove_instance_nocalls(CPUHP_NET_MVNETA_DEAD,

					    &pp->node_dead);

err_free_online_hp:

	cpuhp_state_remove_instance_nocalls(online_hpstate, &pp->node_online);

err_free_irq:

err_free_irq:

	unregister_cpu_notifier(&pp->cpu_notifier);

	on_each_cpu(mvneta_percpu_disable, pp, true);

	on_each_cpu(mvneta_percpu_disable, pp, true);

	free_percpu_irq(pp->dev->irq, pp->ports);

	free_percpu_irq(pp->dev->irq, pp->ports);

err_cleanup_txqs:

err_cleanup_txqs:
@@ -3484,7 +3501,10 @@ static int mvneta_stop(struct net_device *dev) 




	mvneta_stop_dev(pp);

	mvneta_stop_dev(pp);

	mvneta_mdio_remove(pp);

	mvneta_mdio_remove(pp);

	unregister_cpu_notifier(&pp->cpu_notifier);



	cpuhp_state_remove_instance_nocalls(online_hpstate, &pp->node_online);

	cpuhp_state_remove_instance_nocalls(CPUHP_NET_MVNETA_DEAD,

					    &pp->node_dead);

	on_each_cpu(mvneta_percpu_disable, pp, true);

	on_each_cpu(mvneta_percpu_disable, pp, true);

	free_percpu_irq(dev->irq, pp->ports);

	free_percpu_irq(dev->irq, pp->ports);

	mvneta_cleanup_rxqs(pp);

	mvneta_cleanup_rxqs(pp);
@@ -4024,7 +4044,6 @@ static int mvneta_probe(struct platform_device *pdev) 
	err = of_property_read_string(dn, "managed", &managed);

	err = of_property_read_string(dn, "managed", &managed);

	pp->use_inband_status = (err == 0 &&

	pp->use_inband_status = (err == 0 &&

				 strcmp(managed, "in-band-status") == 0);

				 strcmp(managed, "in-band-status") == 0);

	pp->cpu_notifier.notifier_call = mvneta_percpu_notifier;





	pp->rxq_def = rxq_def;

	pp->rxq_def = rxq_def;
@@ -4227,7 +4246,42 @@ static struct platform_driver mvneta_driver = { 
	},

	},

};

};





module_platform_driver(mvneta_driver);

static int __init mvneta_driver_init(void)

{

	int ret;



	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "net/mvmeta:online",

				      mvneta_cpu_online,

				      mvneta_cpu_down_prepare);

	if (ret < 0)

		goto out;

	online_hpstate = ret;

	ret = cpuhp_setup_state_multi(CPUHP_NET_MVNETA_DEAD, "net/mvneta:dead",

				      NULL, mvneta_cpu_dead);

	if (ret)

		goto err_dead;



	ret = platform_driver_register(&mvneta_driver);

	if (ret)

		goto err;

	return 0;



err:

	cpuhp_remove_multi_state(CPUHP_NET_MVNETA_DEAD);

err_dead:

	cpuhp_remove_multi_state(online_hpstate);

out:

	return ret;

}

module_init(mvneta_driver_init);



static void __exit mvneta_driver_exit(void)

{

	platform_driver_unregister(&mvneta_driver);

	cpuhp_remove_multi_state(CPUHP_NET_MVNETA_DEAD);

	cpuhp_remove_multi_state(online_hpstate);

}

module_exit(mvneta_driver_exit);





MODULE_DESCRIPTION("Marvell NETA Ethernet Driver - www.marvell.com");

MODULE_DESCRIPTION("Marvell NETA Ethernet Driver - www.marvell.com");

MODULE_AUTHOR("Rami Rosen <rosenr@marvell.com>, Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");

MODULE_AUTHOR("Rami Rosen <rosenr@marvell.com>, Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");

include/linux/cpuhotplug.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -18,6 +18,7 @@ enum cpuhp_state { 
	CPUHP_SLUB_DEAD,

	CPUHP_SLUB_DEAD,

	CPUHP_MM_WRITEBACK_DEAD,

	CPUHP_MM_WRITEBACK_DEAD,

	CPUHP_SOFTIRQ_DEAD,

	CPUHP_SOFTIRQ_DEAD,

	CPUHP_NET_MVNETA_DEAD,

	CPUHP_WORKQUEUE_PREP,

	CPUHP_WORKQUEUE_PREP,

	CPUHP_POWER_NUMA_PREPARE,

	CPUHP_POWER_NUMA_PREPARE,

	CPUHP_HRTIMERS_PREPARE,

	CPUHP_HRTIMERS_PREPARE,