Commit 97fe626c authored by Kim Phillips's avatar Kim Phillips Committed by Greg Kroah-Hartman
Browse files

coresight: etm3x: Allow etm3x to be built as a module 



Allow to build coresight-etm3x as a module, for ease of development.

- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to
  be called coresight-etm3x by the Makefile
- add an etm_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
- delay advertising the per-cpu etmdrvdata
- protect etmdrvdata[] by modifying it on relevant CPU

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: default avatarMike Leach <mike.leach@linaro.org>
Signed-off-by: default avatarKim Phillips <kim.phillips@arm.com>
Signed-off-by: default avatarTingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-10-mathieu.poirier@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 716f5652

drivers/hwtracing/coresight/Kconfig

+4 −1
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ config CORESIGHT_SINK_ETBV10 
	  special enhancement or added features.



config CORESIGHT_SOURCE_ETM3X

	bool "CoreSight Embedded Trace Macrocell 3.x driver"

	tristate "CoreSight Embedded Trace Macrocell 3.x driver"

	depends on !ARM64

	select CORESIGHT_LINKS_AND_SINKS

	help
@@ -74,6 +74,9 @@ config CORESIGHT_SOURCE_ETM3X 
	  This is primarily useful for instruction level tracing.  Depending

	  the ETM version data tracing may also be available.



	  To compile this driver as a module, choose M here: the

	  module will be called coresight-etm3x.



config CORESIGHT_SOURCE_ETM4X

	bool "CoreSight Embedded Trace Macrocell 4.x driver"

	depends on ARM64

drivers/hwtracing/coresight/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -11,7 +11,8 @@ obj-$(CONFIG_CORESIGHT_SINK_TPIU) += coresight-tpiu.o 
obj-$(CONFIG_CORESIGHT_SINK_ETBV10) += coresight-etb10.o

obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \

					   coresight-replicator.o

obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o \

obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o

coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \

		     coresight-etm3x-sysfs.o

obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \

					coresight-etm4x-sysfs.o

drivers/hwtracing/coresight/coresight-etm3x.c→drivers/hwtracing/coresight/coresight-etm3x-core.c

+115 −39
Original line number Diff line number Diff line
@@ -40,8 +40,6 @@ 
static int boot_enable;

module_param_named(boot_enable, boot_enable, int, S_IRUGO);



/* The number of ETM/PTM currently registered */

static int etm_count;

static struct etm_drvdata *etmdrvdata[NR_CPUS];



static enum cpuhp_state hp_online;
@@ -782,6 +780,42 @@ static void etm_init_trace_id(struct etm_drvdata *drvdata) 
	drvdata->traceid = coresight_get_trace_id(drvdata->cpu);

}



static int __init etm_hp_setup(void)

{

	int ret;



	ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,

						   "arm/coresight:starting",

						   etm_starting_cpu, etm_dying_cpu);



	if (ret)

		return ret;



	ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,

						   "arm/coresight:online",

						   etm_online_cpu, NULL);



	/* HP dyn state ID returned in ret on success */

	if (ret > 0) {

		hp_online = ret;

		return 0;

	}



	/* failed dyn state - remove others */

	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);



	return ret;

}



static void etm_hp_clear(void)

{

	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);

	if (hp_online) {

		cpuhp_remove_state_nocalls(hp_online);

		hp_online = 0;

	}

}



static int etm_probe(struct amba_device *adev, const struct amba_id *id)

{

	int ret;
@@ -823,39 +857,20 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) 
	if (!desc.name)

		return -ENOMEM;



	cpus_read_lock();

	etmdrvdata[drvdata->cpu] = drvdata;



	if (smp_call_function_single(drvdata->cpu,

				     etm_init_arch_data,  drvdata, 1))

		dev_err(dev, "ETM arch init failed\n");



	if (!etm_count++) {

		cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ARM_CORESIGHT_STARTING,

						     "arm/coresight:starting",

						     etm_starting_cpu, etm_dying_cpu);

		ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,

							   "arm/coresight:online",

							   etm_online_cpu, NULL);

		if (ret < 0)

			goto err_arch_supported;

		hp_online = ret;

	}

	cpus_read_unlock();



	if (etm_arch_supported(drvdata->arch) == false) {

		ret = -EINVAL;

		goto err_arch_supported;

	}

	if (etm_arch_supported(drvdata->arch) == false)

		return -EINVAL;



	etm_init_trace_id(drvdata);

	etm_set_default(&drvdata->config);



	pdata = coresight_get_platform_data(dev);

	if (IS_ERR(pdata)) {

		ret = PTR_ERR(pdata);

		goto err_arch_supported;

	}

	if (IS_ERR(pdata))

		return PTR_ERR(pdata);



	adev->dev.platform_data = pdata;



	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
@@ -865,17 +880,17 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) 
	desc.dev = dev;

	desc.groups = coresight_etm_groups;

	drvdata->csdev = coresight_register(&desc);

	if (IS_ERR(drvdata->csdev)) {

		ret = PTR_ERR(drvdata->csdev);

		goto err_arch_supported;

	}

	if (IS_ERR(drvdata->csdev))

		return PTR_ERR(drvdata->csdev);



	ret = etm_perf_symlink(drvdata->csdev, true);

	if (ret) {

		coresight_unregister(drvdata->csdev);

		goto err_arch_supported;

		return ret;

	}



	etmdrvdata[drvdata->cpu] = drvdata;



	pm_runtime_put(&adev->dev);

	dev_info(&drvdata->csdev->dev,

		 "%s initialized\n", (char *)coresight_get_uci_data(id));
@@ -885,14 +900,40 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) 
	}



	return 0;

}



err_arch_supported:

	if (--etm_count == 0) {

		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);

		if (hp_online)

			cpuhp_remove_state_nocalls(hp_online);

static void __exit clear_etmdrvdata(void *info)

{

	int cpu = *(int *)info;



	etmdrvdata[cpu] = NULL;

}

	return ret;



static int __exit etm_remove(struct amba_device *adev)

{

	struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);



	etm_perf_symlink(drvdata->csdev, false);



	/*

	 * Taking hotplug lock here to avoid racing between etm_remove and

	 * CPU hotplug call backs.

	 */

	cpus_read_lock();

	/*

	 * The readers for etmdrvdata[] are CPU hotplug call backs

	 * and PM notification call backs. Change etmdrvdata[i] on

	 * CPU i ensures these call backs has consistent view

	 * inside one call back function.

	 */

	if (smp_call_function_single(drvdata->cpu, clear_etmdrvdata, &drvdata->cpu, 1))

		etmdrvdata[drvdata->cpu] = NULL;



	cpus_read_unlock();



	coresight_unregister(drvdata->csdev);



	return 0;

}



#ifdef CONFIG_PM
@@ -937,6 +978,8 @@ static const struct amba_id etm_ids[] = { 
	{ 0, 0},

};



MODULE_DEVICE_TABLE(amba, etm_ids);



static struct amba_driver etm_driver = {

	.drv = {

		.name	= "coresight-etm3x",
@@ -945,6 +988,39 @@ static struct amba_driver etm_driver = { 
		.suppress_bind_attrs = true,

	},

	.probe		= etm_probe,

	.remove         = etm_remove,

	.id_table	= etm_ids,

};

builtin_amba_driver(etm_driver);
 


static int __init etm_init(void)

{

	int ret;



	ret = etm_hp_setup();



	/* etm_hp_setup() does its own cleanup - exit on error */

	if (ret)

		return ret;



	ret = amba_driver_register(&etm_driver);

	if (ret) {

		pr_err("Error registering etm3x driver\n");

		etm_hp_clear();

	}



	return ret;

}



static void __exit etm_exit(void)

{

	amba_driver_unregister(&etm_driver);

	etm_hp_clear();

}



module_init(etm_init);

module_exit(etm_exit);



MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");

MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");

MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace driver");

MODULE_LICENSE("GPL v2");

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