From 58eb457be0283d9bfc3024eeefea33715391443f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Jul 2016 17:16:55 +0000 Subject: hwtracing/coresight-etm4x: Convert to hotplug state machine This driver has an asymmetry of ONLINE code without any corresponding tear down code. Otherwise, this is a straightforward conversion. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Anna-Maria Gleixner Acked-by: Mathieu Poirier Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.228918408@linutronix.de Signed-off-by: Ingo Molnar --- drivers/hwtracing/coresight/coresight-etm4x.c | 87 +++++++++++++++------------ 1 file changed, 49 insertions(+), 38 deletions(-) (limited to 'drivers/hwtracing') diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 462f0dc15757..1a5e0d14c1dd 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -48,6 +48,8 @@ static int etm4_count; static struct etmv4_drvdata *etmdrvdata[NR_CPUS]; static void etm4_set_default(struct etmv4_config *config); +static enum cpuhp_state hp_online; + static void etm4_os_unlock(struct etmv4_drvdata *drvdata) { /* Writing any value to ETMOSLAR unlocks the trace registers */ @@ -673,47 +675,44 @@ void etm4_config_trace_mode(struct etmv4_config *config) config->addr_acc[ETM_DEFAULT_ADDR_COMP + 1] = addr_acc; } -static int etm4_cpu_callback(struct notifier_block *nfb, unsigned long action, - void *hcpu) +static int etm4_online_cpu(unsigned int cpu) { - unsigned int cpu = (unsigned long)hcpu; - if (!etmdrvdata[cpu]) - goto out; - - switch (action & (~CPU_TASKS_FROZEN)) { - case CPU_STARTING: - spin_lock(&etmdrvdata[cpu]->spinlock); - if (!etmdrvdata[cpu]->os_unlock) { - etm4_os_unlock(etmdrvdata[cpu]); - etmdrvdata[cpu]->os_unlock = true; - } - - if (local_read(&etmdrvdata[cpu]->mode)) - etm4_enable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - break; + return 0; - case CPU_ONLINE: - if (etmdrvdata[cpu]->boot_enable && - !etmdrvdata[cpu]->sticky_enable) - coresight_enable(etmdrvdata[cpu]->csdev); - break; + if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable) + coresight_enable(etmdrvdata[cpu]->csdev); + return 0; +} - case CPU_DYING: - spin_lock(&etmdrvdata[cpu]->spinlock); - if (local_read(&etmdrvdata[cpu]->mode)) - etm4_disable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - break; +static int etm4_starting_cpu(unsigned int cpu) +{ + if (!etmdrvdata[cpu]) + return 0; + + spin_lock(&etmdrvdata[cpu]->spinlock); + if (!etmdrvdata[cpu]->os_unlock) { + etm4_os_unlock(etmdrvdata[cpu]); + etmdrvdata[cpu]->os_unlock = true; } -out: - return NOTIFY_OK; + + if (local_read(&etmdrvdata[cpu]->mode)) + etm4_enable_hw(etmdrvdata[cpu]); + spin_unlock(&etmdrvdata[cpu]->spinlock); + return 0; } -static struct notifier_block etm4_cpu_notifier = { - .notifier_call = etm4_cpu_callback, -}; +static int etm4_dying_cpu(unsigned int cpu) +{ + if (!etmdrvdata[cpu]) + return 0; + + spin_lock(&etmdrvdata[cpu]->spinlock); + if (local_read(&etmdrvdata[cpu]->mode)) + etm4_disable_hw(etmdrvdata[cpu]); + spin_unlock(&etmdrvdata[cpu]->spinlock); + return 0; +} static void etm4_init_trace_id(struct etmv4_drvdata *drvdata) { @@ -767,8 +766,17 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) etm4_init_arch_data, drvdata, 1)) dev_err(dev, "ETM arch init failed\n"); - if (!etm4_count++) - register_hotcpu_notifier(&etm4_cpu_notifier); + if (!etm4_count++) { + cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT4_STARTING, + "AP_ARM_CORESIGHT4_STARTING", + etm4_starting_cpu, etm4_dying_cpu); + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "AP_ARM_CORESIGHT4_ONLINE", + etm4_online_cpu, NULL); + if (ret < 0) + goto err_arch_supported; + hp_online = ret; + } put_online_cpus(); @@ -809,8 +817,11 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) return 0; err_arch_supported: - if (--etm4_count == 0) - unregister_hotcpu_notifier(&etm4_cpu_notifier); + if (--etm4_count == 0) { + cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT4_STARTING); + if (hp_online) + cpuhp_remove_state_nocalls(hp_online); + } return ret; } -- cgit v1.2.3