Commit 5c0016d7 authored by Mao Jinlong's avatar Mao Jinlong Committed by Suzuki K Poulose
Browse files

coresight: core: Use IDR for non-cpu bound sources' paths. 



Except stm, there could be other sources which are not associated
with cpus. Use IDR to store and search these sources' paths.

Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: default avatarMike Leach <mike.leach@linaro.org>
Signed-off-by: default avatarMao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-2-quic_jinlmao@quicinc.com
parent fd30b085

drivers/hwtracing/coresight/coresight-core.c

+26 −11
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/types.h>

#include <linux/device.h>

#include <linux/io.h>

#include <linux/idr.h>

#include <linux/err.h>

#include <linux/export.h>

#include <linux/slab.h>
@@ -26,6 +27,13 @@ 
static DEFINE_MUTEX(coresight_mutex);

static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);



/*

 * Use IDR to map the hash of the source's device name

 * to the pointer of path for the source. The idr is for

 * the sources which aren't associated with CPU.

 */

static DEFINE_IDR(path_idr);



/**

 * struct coresight_node - elements of a path, from source to sink

 * @csdev:	Address of an element.
@@ -42,14 +50,6 @@ struct coresight_node { 
 */

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;



/*

 * When losing synchronisation a new barrier packet needs to be inserted at the

 * beginning of the data collected in a buffer.  That way the decoder knows that
@@ -1075,6 +1075,7 @@ int coresight_enable(struct coresight_device *csdev) 
	struct coresight_device *sink;

	struct list_head *path;

	enum coresight_dev_subtype_source subtype;

	u32 hash;



	subtype = csdev->subtype.source_subtype;
@@ -1129,7 +1130,14 @@ int coresight_enable(struct coresight_device *csdev) 
		per_cpu(tracer_path, cpu) = path;

		break;

	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:

		stm_path = path;

		/*

		 * Use the hash of source's device name as ID

		 * and map the ID to the pointer of the path.

		 */

		hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));

		ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL);

		if (ret)

			goto err_source;

		break;

	default:

		/* We can't be here */
@@ -1153,6 +1161,7 @@ void coresight_disable(struct coresight_device *csdev) 
{

	int cpu, ret;

	struct list_head *path = NULL;

	u32 hash;



	mutex_lock(&coresight_mutex);
@@ -1170,14 +1179,20 @@ void coresight_disable(struct coresight_device *csdev) 
		per_cpu(tracer_path, cpu) = NULL;

		break;

	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:

		path = stm_path;

		stm_path = NULL;

		hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));

		/* Find the path by the hash. */

		path = idr_find(&path_idr, hash);

		if (path == NULL) {

			pr_err("Path is not found for %s\n", dev_name(&csdev->dev));

			goto out;

		}

		break;

	default:

		/* We can't be here */

		break;

	}



	idr_remove(&path_idr, hash);

	coresight_disable_path(path);

	coresight_release_path(path);