From mboxrd@z Thu Jan 1 00:00:00 1970 From: anna-maria@linutronix.de (Anna-Maria Gleixner) Date: Wed, 13 Jul 2016 17:16:54 -0000 Subject: [patch V2 51/67] hwtracing/coresight-etm3x: Convert to hotplug state machine References: <20160713153219.128052238@linutronix.de> Message-ID: <20160713153337.147128995@linutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Richard Cochran This driver has an asymmetry of ONLINE code without any corresponding tear down code. Otherwise, this is a straightforward conversion. Signed-off-by: Richard Cochran Reviewed-by: Sebastian Andrzej Siewior Acked-by: Mathieu Poirier Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arm-kernel at lists.infradead.org Signed-off-by: Anna-Maria Gleixner --- drivers/hwtracing/coresight/coresight-etm3x.c | 90 ++++++++++++++------------ include/linux/cpuhotplug.h | 1 2 files changed, 50 insertions(+), 41 deletions(-) --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -51,6 +51,8 @@ module_param_named(boot_enable, boot_ena static int etm_count; static struct etm_drvdata *etmdrvdata[NR_CPUS]; +static enum cpuhp_state hp_online; + /* * Memory mapped writes to clear os lock are not supported on some processors * and OS lock must be unlocked before any memory mapped access on such @@ -481,8 +483,7 @@ static int etm_enable_sysfs(struct cores /* * Configure the ETM only if the CPU is online. If it isn't online - * hw configuration will take place when 'CPU_STARTING' is received - * in @etm_cpu_callback. + * hw configuration will take place on the local CPU during bring up. */ if (cpu_online(drvdata->cpu)) { ret = smp_call_function_single(drvdata->cpu, @@ -641,47 +642,44 @@ static const struct coresight_ops etm_cs .source_ops = &etm_source_ops, }; -static int etm_cpu_callback(struct notifier_block *nfb, unsigned long action, - void *hcpu) +static int etm_online_cpu(unsigned int cpu) { - unsigned int cpu = (unsigned long)hcpu; - if (!etmdrvdata[cpu]) - goto out; + return 0; - switch (action & (~CPU_TASKS_FROZEN)) { - case CPU_STARTING: - spin_lock(&etmdrvdata[cpu]->spinlock); - if (!etmdrvdata[cpu]->os_unlock) { - etm_os_unlock(etmdrvdata[cpu]); - etmdrvdata[cpu]->os_unlock = true; - } - - if (local_read(&etmdrvdata[cpu]->mode)) - etm_enable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - break; + if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable) + coresight_enable(etmdrvdata[cpu]->csdev); + return 0; +} - case CPU_ONLINE: - if (etmdrvdata[cpu]->boot_enable && - !etmdrvdata[cpu]->sticky_enable) - coresight_enable(etmdrvdata[cpu]->csdev); - break; +static int etm_starting_cpu(unsigned int cpu) +{ + if (!etmdrvdata[cpu]) + return 0; - case CPU_DYING: - spin_lock(&etmdrvdata[cpu]->spinlock); - if (local_read(&etmdrvdata[cpu]->mode)) - etm_disable_hw(etmdrvdata[cpu]); - spin_unlock(&etmdrvdata[cpu]->spinlock); - break; + spin_lock(&etmdrvdata[cpu]->spinlock); + if (!etmdrvdata[cpu]->os_unlock) { + etm_os_unlock(etmdrvdata[cpu]); + etmdrvdata[cpu]->os_unlock = true; } -out: - return NOTIFY_OK; + + if (local_read(&etmdrvdata[cpu]->mode)) + etm_enable_hw(etmdrvdata[cpu]); + spin_unlock(&etmdrvdata[cpu]->spinlock); + return 0; } -static struct notifier_block etm_cpu_notifier = { - .notifier_call = etm_cpu_callback, -}; +static int etm_dying_cpu(unsigned int cpu) +{ + if (!etmdrvdata[cpu]) + return 0; + + spin_lock(&etmdrvdata[cpu]->spinlock); + if (local_read(&etmdrvdata[cpu]->mode)) + etm_disable_hw(etmdrvdata[cpu]); + spin_unlock(&etmdrvdata[cpu]->spinlock); + return 0; +} static bool etm_arch_supported(u8 arch) { @@ -806,9 +804,17 @@ static int etm_probe(struct amba_device etm_init_arch_data, drvdata, 1)) dev_err(dev, "ETM arch init failed\n"); - if (!etm_count++) - register_hotcpu_notifier(&etm_cpu_notifier); - + if (!etm_count++) { + cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, + "AP_ARM_CORESIGHT_STARTING", + etm_starting_cpu, etm_dying_cpu); + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "AP_ARM_CORESIGHT_ONLINE", + etm_online_cpu, NULL); + if (ret < 0) + goto err_arch_supported; + hp_online = ret; + } put_online_cpus(); if (etm_arch_supported(drvdata->arch) == false) { @@ -839,7 +845,6 @@ static int etm_probe(struct amba_device pm_runtime_put(&adev->dev); dev_info(dev, "%s initialized\n", (char *)id->data); - if (boot_enable) { coresight_enable(drvdata->csdev); drvdata->boot_enable = true; @@ -848,8 +853,11 @@ static int etm_probe(struct amba_device return 0; err_arch_supported: - if (--etm_count == 0) - unregister_hotcpu_notifier(&etm_cpu_notifier); + if (--etm_count == 0) { + cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); + if (hp_online) + cpuhp_remove_state_nocalls(hp_online); + } return ret; } --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -50,6 +50,7 @@ enum cpuhp_state { CPUHP_AP_KVM_ARM_VGIC_STARTING, CPUHP_AP_KVM_ARM_TIMER_STARTING, CPUHP_AP_ARM_XEN_STARTING, + CPUHP_AP_ARM_CORESIGHT_STARTING, CPUHP_AP_LEDTRIG_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE,