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Commit 58eb457b authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Ingo Molnar
Browse files

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: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Acked-by: default avatarMathieu 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/20160713153337.228918408@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 2b5283d1

drivers/hwtracing/coresight/coresight-etm4x.c

+49 −38
Original line number Diff line number Diff line
@@ -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 */
@@ -673,16 +675,21 @@ 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])

		return 0;



	if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable)

		coresight_enable(etmdrvdata[cpu]->csdev);

	return 0;

}



static int etm4_starting_cpu(unsigned int cpu)

{

	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) {

		etm4_os_unlock(etmdrvdata[cpu]);
@@ -692,29 +699,21 @@ static int etm4_cpu_callback(struct notifier_block *nfb, unsigned long action, 
	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;

static int etm4_dying_cpu(unsigned int cpu)

{

	if (!etmdrvdata[cpu])

		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;

	}

out:

	return NOTIFY_OK;

	return 0;

}



static struct notifier_block etm4_cpu_notifier = {

	.notifier_call = etm4_cpu_callback,

};



static void etm4_init_trace_id(struct etmv4_drvdata *drvdata)

{

	drvdata->trcid = coresight_get_trace_id(drvdata->cpu);
@@ -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;

}

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ enum cpuhp_state { 
	CPUHP_AP_KVM_ARM_TIMER_STARTING,

	CPUHP_AP_ARM_XEN_STARTING,

	CPUHP_AP_ARM_CORESIGHT_STARTING,

	CPUHP_AP_ARM_CORESIGHT4_STARTING,

	CPUHP_AP_LEDTRIG_STARTING,

	CPUHP_AP_NOTIFY_STARTING,

	CPUHP_AP_ONLINE,