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[v11,1/9] coresight: core: Use IDR for non-cpu bound sources' paths.

Message ID 20220620120101.2906-2-quic_jinlmao@quicinc.com
State Superseded
Headers show
Series [v11,1/9] coresight: core: Use IDR for non-cpu bound sources' paths. | expand

Commit Message

Mao Jinlong June 20, 2022, noon UTC 
Except stm, there could be other sources which are not associated
with cpus. Use IDR to store and search these sources' paths.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 37 ++++++++++++++------
 1 file changed, 26 insertions(+), 11 deletions(-)

Comments

Suzuki K Poulose July 1, 2022, 9:29 a.m. UTC | #1 
On 20/06/2022 13:00, Mao Jinlong wrote:
> Except stm, there could be other sources which are not associated
> with cpus. Use IDR to store and search these sources' paths.
> 
> Reviewed-by: Mike Leach <mike.leach@linaro.org>
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
diff mbox series

Patch

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index da416800a7de..eace5b7ada02 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -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>
@@ -27,6 +28,13 @@ 
 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.
@@ -43,14 +51,6 @@  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;
-
 /*
  * Set up a global trace ID map.
  * We may need a per sink ID map in future for larger / multi sink systems.
@@ -1061,6 +1061,7 @@  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;
 
@@ -1115,7 +1116,14 @@  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 */
@@ -1139,6 +1147,7 @@  void coresight_disable(struct coresight_device *csdev)
 {
 	int cpu, ret;
 	struct list_head *path = NULL;
+	u32 hash;
 
 	mutex_lock(&coresight_mutex);
 
@@ -1156,14 +1165,20 @@  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);