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Commit a685d683 authored by Mathieu Poirier's avatar Mathieu Poirier Committed by Greg Kroah-Hartman
Browse files

coresight: adding path for STM device 



>From a core framework point of view an STM device is a source that is
treated the same way as any other tracers.  Unlike tracers though STM
devices are not associated with a CPU.  As such it doesn't make sense
to associate the path from an STM device to its sink with a per-cpu
variable as it is done for tracers.

This patch simply adds another global variable to keep STM paths and the
processing in coresight_enable/disable() is updated to deal with STM
devices properly.

Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8e996a28

drivers/hwtracing/coresight/coresight.c

+82 −24
Original line number Original line Diff line number Diff line
@@ -43,7 +43,15 @@ struct coresight_node { 
 * When operating Coresight drivers from the sysFS interface, only a single

 * When operating Coresight drivers from the sysFS interface, only a single

 * path can exist from a tracer (associated to a CPU) to a sink.

 * path can exist from a tracer (associated to a CPU) to a sink.

 */

 */

static DEFINE_PER_CPU(struct list_head *, sysfs_path);

static DEFINE_PER_CPU(struct list_head *, tracer_path);



/*

 * As of this writing only a single STM can be found in CS topologies.  Since

 * there is no way to know if we'll ever see more and what kind of

 * configuration they will enact, for the time being only define a single path

 * for STM.

 */

static struct list_head *stm_path;





static int coresight_id_match(struct device *dev, void *data)

static int coresight_id_match(struct device *dev, void *data)

{

{
@@ -432,18 +440,45 @@ void coresight_release_path(struct list_head *path) 
	path = NULL;

	path = NULL;

}

}





/** coresight_validate_source - make sure a source has the right credentials

 *  @csdev:	the device structure for a source.

 *  @function:	the function this was called from.

 *

 * Assumes the coresight_mutex is held.

 */

static int coresight_validate_source(struct coresight_device *csdev,

				     const char *function)

{

	u32 type, subtype;



	type = csdev->type;

	subtype = csdev->subtype.source_subtype;



	if (type != CORESIGHT_DEV_TYPE_SOURCE) {

		dev_err(&csdev->dev, "wrong device type in %s\n", function);

		return -EINVAL;

	}



	if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&

	    subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {

		dev_err(&csdev->dev, "wrong device subtype in %s\n", function);

		return -EINVAL;

	}



	return 0;

}



int coresight_enable(struct coresight_device *csdev)

int coresight_enable(struct coresight_device *csdev)

{

{

	int ret = 0;

	int cpu, ret = 0;

	int cpu;

	struct list_head *path;

	struct list_head *path;





	mutex_lock(&coresight_mutex);

	mutex_lock(&coresight_mutex);

	if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {



		ret = -EINVAL;

	ret = coresight_validate_source(csdev, __func__);

		dev_err(&csdev->dev, "wrong device type in %s\n", __func__);

	if (ret)

		goto out;

		goto out;

	}



	if (csdev->enable)

	if (csdev->enable)

		goto out;

		goto out;
@@ -461,6 +496,8 @@ int coresight_enable(struct coresight_device *csdev) 
	if (ret)

	if (ret)

		goto err_source;

		goto err_source;





	switch (csdev->subtype.source_subtype) {

	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:

		/*

		/*

		 * When working from sysFS it is important to keep track

		 * When working from sysFS it is important to keep track

		 * of the paths that were created so that they can be

		 * of the paths that were created so that they can be
@@ -469,7 +506,15 @@ int coresight_enable(struct coresight_device *csdev) 
		 * a per-cpu variable will do just fine.

		 * a per-cpu variable will do just fine.

		 */

		 */

		cpu = source_ops(csdev)->cpu_id(csdev);

		cpu = source_ops(csdev)->cpu_id(csdev);

	per_cpu(sysfs_path, cpu) = path;

		per_cpu(tracer_path, cpu) = path;

		break;

	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:

		stm_path = path;

		break;

	default:

		/* We can't be here */

		break;

	}





out:

out:

	mutex_unlock(&coresight_mutex);

	mutex_unlock(&coresight_mutex);
@@ -486,23 +531,36 @@ EXPORT_SYMBOL_GPL(coresight_enable); 




void coresight_disable(struct coresight_device *csdev)

void coresight_disable(struct coresight_device *csdev)

{

{

	int cpu;

	int cpu, ret;

	struct list_head *path;

	struct list_head *path = NULL;





	mutex_lock(&coresight_mutex);

	mutex_lock(&coresight_mutex);

	if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {



		dev_err(&csdev->dev, "wrong device type in %s\n", __func__);

	ret = coresight_validate_source(csdev, __func__);

	if (ret)

		goto out;

		goto out;

	}



	if (!csdev->enable)

	if (!csdev->enable)

		goto out;

		goto out;





	switch (csdev->subtype.source_subtype) {

	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:

		cpu = source_ops(csdev)->cpu_id(csdev);

		cpu = source_ops(csdev)->cpu_id(csdev);

	path = per_cpu(sysfs_path, cpu);

		path = per_cpu(tracer_path, cpu);

		per_cpu(tracer_path, cpu) = NULL;

		break;

	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:

		path = stm_path;

		stm_path = NULL;

		break;

	default:

		/* We can't be here */

		break;

	}



	coresight_disable_source(csdev);

	coresight_disable_source(csdev);

	coresight_disable_path(path);

	coresight_disable_path(path);

	coresight_release_path(path);

	coresight_release_path(path);

	per_cpu(sysfs_path, cpu) = NULL;





out:

out:

	mutex_unlock(&coresight_mutex);

	mutex_unlock(&coresight_mutex);