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hwtracing/coresight-etm3x: Convert to hotplug state machine

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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 <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.147128995@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Richard Cochran 2016-07-13 17:16:54 +00:00 committed by Ingo Molnar
parent 65264e3bc3
commit 2b5283d12f
2 changed files with 53 additions and 44 deletions
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96
drivers/hwtracing/coresight/coresight-etm3x.c
View file

@ -51,6 +51,8 @@ module_param_named(boot_enable, boot_enable, int, S_IRUGO);
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 coresight_device *csdev)
/*
* 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_ops = {
.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;
case CPU_ONLINE:
if (etmdrvdata[cpu]->boot_enable &&
!etmdrvdata[cpu]->sticky_enable)
coresight_enable(etmdrvdata[cpu]->csdev);
break;
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;
}
out:
return NOTIFY_OK;
if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable)
coresight_enable(etmdrvdata[cpu]->csdev);
return 0;
}
static struct notifier_block etm_cpu_notifier = {
.notifier_call = etm_cpu_callback,
};
static int etm_starting_cpu(unsigned int cpu)
{
if (!etmdrvdata[cpu])
return 0;
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);
return 0;
}
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 *adev, const struct amba_id *id)
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 *adev, const struct amba_id *id)
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 *adev, const struct amba_id *id)
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;
}

1
include/linux/cpuhotplug.h
View file

@ -49,6 +49,7 @@ 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,