Commit 22a550a3 authored by Kim Phillips's avatar Kim Phillips Committed by Greg Kroah-Hartman
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coresight: etm4x: Allow etm4x to be built as a module 



Allow to build coresight-etm4x 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-etm4x by the Makefile
- add an etm4_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>
Tested-by: default avatarMike Leach <mike.leach@linaro.org>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
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/20200928163513.70169-11-mathieu.poirier@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 97fe626c

drivers/hwtracing/coresight/Kconfig

+4 −1
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ config CORESIGHT_SOURCE_ETM3X 
	  module will be called coresight-etm3x.



config CORESIGHT_SOURCE_ETM4X

	bool "CoreSight Embedded Trace Macrocell 4.x driver"

	tristate "CoreSight Embedded Trace Macrocell 4.x driver"

	depends on ARM64

	select CORESIGHT_LINKS_AND_SINKS

	select PID_IN_CONTEXTIDR
@@ -88,6 +88,9 @@ config CORESIGHT_SOURCE_ETM4X 
	  for instruction level tracing. Depending on the implemented version

	  data tracing may also be available.



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

	  module will be called coresight-etm4x.



config CORESIGHT_STM

	tristate "CoreSight System Trace Macrocell driver"

	depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64

drivers/hwtracing/coresight/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -14,8 +14,8 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \ 
obj-$(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

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

coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o

obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o

obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o

obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o

drivers/hwtracing/coresight/coresight-etm4x.c→drivers/hwtracing/coresight/coresight-etm4x-core.c

+63 −21
Original line number Diff line number Diff line
@@ -1447,7 +1447,7 @@ unregister_notifier: 
	return ret;

}



static void __init etm4_pm_clear(void)

static void etm4_pm_clear(void)

{

	cpu_pm_unregister_notifier(&etm4_cpu_pm_nb);

	cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
@@ -1504,25 +1504,20 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) 
	if (!desc.name)

		return -ENOMEM;



	etmdrvdata[drvdata->cpu] = drvdata;



	if (smp_call_function_single(drvdata->cpu,

				etm4_init_arch_data,  drvdata, 1))

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



	if (etm4_arch_supported(drvdata->arch) == false) {

		ret = -EINVAL;

		goto err_arch_supported;

	}

	if (etm4_arch_supported(drvdata->arch) == false)

		return -EINVAL;



	etm4_init_trace_id(drvdata);

	etm4_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;
@@ -1532,17 +1527,17 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) 
	desc.dev = dev;

	desc.groups = coresight_etmv4_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, "CPU%d: ETM v%d.%d initialized\n",

		 drvdata->cpu, drvdata->arch >> 4, drvdata->arch & 0xf);
@@ -1553,10 +1548,6 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) 
	}



	return 0;



err_arch_supported:

	etmdrvdata[drvdata->cpu] = NULL;

	return ret;

}



static struct amba_cs_uci_id uci_id_etm4[] = {
@@ -1568,6 +1559,40 @@ static struct amba_cs_uci_id uci_id_etm4[] = { 
	}

};



static void __exit clear_etmdrvdata(void *info)

{

	int cpu = *(int *)info;



	etmdrvdata[cpu] = NULL;

}



static int __exit etm4_remove(struct amba_device *adev)

{

	struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);



	etm_perf_symlink(drvdata->csdev, false);



	/*

	 * Taking hotplug lock here to avoid racing between etm4_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;

}



static const struct amba_id etm4_ids[] = {

	CS_AMBA_ID(0x000bb95d),			/* Cortex-A53 */

	CS_AMBA_ID(0x000bb95e),			/* Cortex-A57 */
@@ -1587,12 +1612,16 @@ static const struct amba_id etm4_ids[] = { 
	{},

};



MODULE_DEVICE_TABLE(amba, etm4_ids);



static struct amba_driver etm4x_driver = {

	.drv = {

		.name   = "coresight-etm4x",

		.owner  = THIS_MODULE,

		.suppress_bind_attrs = true,

	},

	.probe		= etm4_probe,

	.remove         = etm4_remove,

	.id_table	= etm4_ids,

};
@@ -1614,4 +1643,17 @@ static int __init etm4x_init(void) 


	return ret;

}

device_initcall(etm4x_init);
 


static void __exit etm4x_exit(void)

{

	amba_driver_unregister(&etm4x_driver);

	etm4_pm_clear();

}



module_init(etm4x_init);

module_exit(etm4x_exit);



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

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

MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4.x driver");

MODULE_LICENSE("GPL v2");

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