]> asedeno.scripts.mit.edu Git - linux.git/commitdiff
net/mvneta: Convert to hotplug state machine
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Thu, 18 Aug 2016 12:57:23 +0000 (14:57 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Tue, 6 Sep 2016 16:30:22 +0000 (18:30 +0200)
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Sebastian 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: Thomas Gleixner <tglx@linutronix.de>
drivers/net/ethernet/marvell/mvneta.c
include/linux/cpuhotplug.h

index d41c28d00b57fa16d2d01160f2168ef675a0e2e2..b74548728fb5e170080a2ca421c826a161ef38f7 100644 (file)
@@ -382,7 +382,8 @@ struct mvneta_port {
        struct mvneta_rx_queue *rxqs;
        struct mvneta_tx_queue *txqs;
        struct net_device *dev;
-       struct notifier_block cpu_notifier;
+       struct hlist_node node_online;
+       struct hlist_node node_dead;
        int rxq_def;
        /* Protect the access to the percpu interrupt registers,
         * ensuring that the configuration remains coherent.
@@ -574,6 +575,7 @@ struct mvneta_rx_queue {
        int next_desc_to_proc;
 };
 
+static enum cpuhp_state online_hpstate;
 /* 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.
  */
@@ -3311,101 +3313,104 @@ static void mvneta_percpu_elect(struct mvneta_port *pp)
        }
 };
 
-static int mvneta_percpu_notifier(struct notifier_block *nfb,
-                                 unsigned long action, void *hcpu)
+static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)
 {
-       struct mvneta_port *pp = container_of(nfb, struct mvneta_port,
-                                             cpu_notifier);
-       int cpu = (unsigned long)hcpu, other_cpu;
+       int other_cpu;
+       struct mvneta_port *pp = hlist_entry_safe(node, struct mvneta_port,
+                                                 node_online);
        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);
-               /* Configuring the driver for a new CPU while the
-                * driver is stopping is racy, so just avoid it.
-                */
-               if (pp->is_stopped) {
-                       spin_unlock(&pp->lock);
-                       break;
-               }
-               netif_tx_stop_all_queues(pp->dev);
 
-               /* We have to synchronise on tha napi of each CPU
-                * except the one just being waked up
-                */
-               for_each_online_cpu(other_cpu) {
-                       if (other_cpu != cpu) {
-                               struct mvneta_pcpu_port *other_port =
-                                       per_cpu_ptr(pp->ports, other_cpu);
+       spin_lock(&pp->lock);
+       /*
+        * Configuring the driver for a new CPU while the driver is
+        * stopping is racy, so just avoid it.
+        */
+       if (pp->is_stopped) {
+               spin_unlock(&pp->lock);
+               return 0;
+       }
+       netif_tx_stop_all_queues(pp->dev);
 
-                               napi_synchronize(&other_port->napi);
-                       }
+       /*
+        * We have to synchronise on tha napi of each CPU except the one
+        * just being woken up
+        */
+       for_each_online_cpu(other_cpu) {
+               if (other_cpu != cpu) {
+                       struct mvneta_pcpu_port *other_port =
+                               per_cpu_ptr(pp->ports, other_cpu);
+
+                       napi_synchronize(&other_port->napi);
                }
+       }
 
-               /* Mask all ethernet port interrupts */
-               on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);
-               napi_enable(&port->napi);
+       /* Mask all ethernet port interrupts */
+       on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);
+       napi_enable(&port->napi);
 
+       /*
+        * Enable per-CPU interrupts on the CPU that is
+        * brought up.
+        */
+       mvneta_percpu_enable(pp);
 
-               /* Enable per-CPU interrupts on the CPU that is
-                * brought up.
-                */
-               mvneta_percpu_enable(pp);
+       /*
+        * Enable per-CPU interrupt on the one CPU we care
+        * about.
+        */
+       mvneta_percpu_elect(pp);
 
-               /* Enable per-CPU interrupt on the one CPU we care
-                * about.
-                */
-               mvneta_percpu_elect(pp);
-
-               /* Unmask all ethernet port interrupts */
-               on_each_cpu(mvneta_percpu_unmask_interrupt, pp, true);
-               mvreg_write(pp, MVNETA_INTR_MISC_MASK,
-                       MVNETA_CAUSE_PHY_STATUS_CHANGE |
-                       MVNETA_CAUSE_LINK_CHANGE |
-                       MVNETA_CAUSE_PSC_SYNC_CHANGE);
-               netif_tx_start_all_queues(pp->dev);
-               spin_unlock(&pp->lock);
-               break;
-       case CPU_DOWN_PREPARE:
-       case CPU_DOWN_PREPARE_FROZEN:
-               netif_tx_stop_all_queues(pp->dev);
-               /* Thanks to this lock we are sure that any pending
-                * cpu election is done
-                */
-               spin_lock(&pp->lock);
-               /* Mask all ethernet port interrupts */
-               on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);
-               spin_unlock(&pp->lock);
+       /* Unmask all ethernet port interrupts */
+       on_each_cpu(mvneta_percpu_unmask_interrupt, pp, true);
+       mvreg_write(pp, MVNETA_INTR_MISC_MASK,
+                   MVNETA_CAUSE_PHY_STATUS_CHANGE |
+                   MVNETA_CAUSE_LINK_CHANGE |
+                   MVNETA_CAUSE_PSC_SYNC_CHANGE);
+       netif_tx_start_all_queues(pp->dev);
+       spin_unlock(&pp->lock);
+       return 0;
+}
 
-               napi_synchronize(&port->napi);
-               napi_disable(&port->napi);
-               /* Disable per-CPU interrupts on the CPU that is
-                * brought down.
-                */
-               mvneta_percpu_disable(pp);
+static int mvneta_cpu_down_prepare(unsigned int cpu, struct hlist_node *node)
+{
+       struct mvneta_port *pp = hlist_entry_safe(node, struct mvneta_port,
+                                                 node_online);
+       struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);
 
-               break;
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-               /* Check if a new CPU must be elected now this on is down */
-               spin_lock(&pp->lock);
-               mvneta_percpu_elect(pp);
-               spin_unlock(&pp->lock);
-               /* Unmask all ethernet port interrupts */
-               on_each_cpu(mvneta_percpu_unmask_interrupt, pp, true);
-               mvreg_write(pp, MVNETA_INTR_MISC_MASK,
-                       MVNETA_CAUSE_PHY_STATUS_CHANGE |
-                       MVNETA_CAUSE_LINK_CHANGE |
-                       MVNETA_CAUSE_PSC_SYNC_CHANGE);
-               netif_tx_start_all_queues(pp->dev);
-               break;
-       }
+       /*
+        * Thanks to this lock we are sure that any pending cpu election is
+        * done.
+        */
+       spin_lock(&pp->lock);
+       /* Mask all ethernet port interrupts */
+       on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);
+       spin_unlock(&pp->lock);
 
-       return NOTIFY_OK;
+       napi_synchronize(&port->napi);
+       napi_disable(&port->napi);
+       /* Disable per-CPU interrupts on the CPU that is brought down. */
+       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);
+
+       /* Check if a new CPU must be elected now this on is down */
+       spin_lock(&pp->lock);
+       mvneta_percpu_elect(pp);
+       spin_unlock(&pp->lock);
+       /* Unmask all ethernet port interrupts */
+       on_each_cpu(mvneta_percpu_unmask_interrupt, pp, true);
+       mvreg_write(pp, MVNETA_INTR_MISC_MASK,
+                   MVNETA_CAUSE_PHY_STATUS_CHANGE |
+                   MVNETA_CAUSE_LINK_CHANGE |
+                   MVNETA_CAUSE_PSC_SYNC_CHANGE);
+       netif_tx_start_all_queues(pp->dev);
+       return 0;
 }
 
 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
         * 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 */
        netif_carrier_off(pp->dev);
@@ -3450,15 +3463,19 @@ static int mvneta_open(struct net_device *dev)
        ret = mvneta_mdio_probe(pp);
        if (ret < 0) {
                netdev_err(dev, "cannot probe MDIO bus\n");
-               goto err_free_irq;
+               goto err_free_dead_hp;
        }
 
        mvneta_start_dev(pp);
 
        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:
-       unregister_cpu_notifier(&pp->cpu_notifier);
        on_each_cpu(mvneta_percpu_disable, pp, true);
        free_percpu_irq(pp->dev->irq, pp->ports);
 err_cleanup_txqs:
@@ -3484,7 +3501,10 @@ static int mvneta_stop(struct net_device *dev)
 
        mvneta_stop_dev(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);
        free_percpu_irq(dev->irq, pp->ports);
        mvneta_cleanup_rxqs(pp);
@@ -4024,7 +4044,6 @@ static int mvneta_probe(struct platform_device *pdev)
        err = of_property_read_string(dn, "managed", &managed);
        pp->use_inband_status = (err == 0 &&
                                 strcmp(managed, "in-band-status") == 0);
-       pp->cpu_notifier.notifier_call = mvneta_percpu_notifier;
 
        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_AUTHOR("Rami Rosen <rosenr@marvell.com>, Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
index a421407a317f338844ce1c440e67053d61fc8127..332b39c21d2ea15cc1b14e2cd80697256c011952 100644 (file)
@@ -18,6 +18,7 @@ enum cpuhp_state {
        CPUHP_SLUB_DEAD,
        CPUHP_MM_WRITEBACK_DEAD,
        CPUHP_SOFTIRQ_DEAD,
+       CPUHP_NET_MVNETA_DEAD,
        CPUHP_WORKQUEUE_PREP,
        CPUHP_POWER_NUMA_PREPARE,
        CPUHP_HRTIMERS_PREPARE,