[PATCH v5 12/19] coresight: sysfs: Use source's path pointer for path control

[Leo Yan]

Since the path pointer is stored in the source's structure, retrieve it
directly when disabling the path.

As a result, the global variables used for caching path pointers are no
longer needed. Remove them to simplify the code.

Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-sysfs.c | 79 +++------------------------
 1 file changed, 9 insertions(+), 70 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index cb1d4f90a9c245b2c2f6e818c0f4d905b86477db..9e94505bccf4ac91207f2f5393ae57ae077d61d6 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -12,19 +12,6 @@
 #include "coresight-priv.h"
 #include "coresight-trace-id.h"
 
-/*
- * 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);
-
-/*
- * When operating Coresight drivers from the sysFS interface, only a single
- * path can exist from a tracer (associated to a CPU) to a sink.
- */
-static DEFINE_PER_CPU(struct coresight_path *, tracer_path);
-
 ssize_t coresight_simple_show_pair(struct device *_dev,
 			      struct device_attribute *attr, char *buf)
 {
@@ -170,11 +157,10 @@ static int coresight_validate_source_sysfs(struct coresight_device *csdev,
 
 int coresight_enable_sysfs(struct coresight_device *csdev)
 {
-	int cpu, ret = 0;
+	int ret = 0;
 	struct coresight_device *sink;
 	struct coresight_path *path;
 	enum coresight_dev_subtype_source subtype;
-	u32 hash;
 
 	subtype = csdev->subtype.source_subtype;
 
@@ -226,35 +212,6 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
 	if (ret)
 		goto err_source;
 
-	switch (subtype) {
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
-		/*
-		 * When working from sysFS it is important to keep track
-		 * of the paths that were created so that they can be
-		 * undone in 'coresight_disable()'.  Since there can only
-		 * be a single session per tracer (when working from sysFS)
-		 * a per-cpu variable will do just fine.
-		 */
-		cpu = source_ops(csdev)->cpu_id(csdev);
-		per_cpu(tracer_path, cpu) = path;
-		break;
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
-		/*
-		 * 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 */
-		break;
-	}
-
 out:
 	mutex_unlock(&coresight_mutex);
 	return ret;
@@ -270,9 +227,8 @@ EXPORT_SYMBOL_GPL(coresight_enable_sysfs);
 
 void coresight_disable_sysfs(struct coresight_device *csdev)
 {
-	int cpu, ret;
-	struct coresight_path *path = NULL;
-	u32 hash;
+	int ret;
+	struct coresight_path *path;
 
 	mutex_lock(&coresight_mutex);
 
@@ -280,32 +236,15 @@ void coresight_disable_sysfs(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
+	/*
+	 * coresight_disable_source_sysfs() clears the 'csdev->path' pointer
+	 * when disabling the source. Retrieve the path pointer here.
+	 */
+	path = csdev->path;
+
 	if (!coresight_disable_source_sysfs(csdev, NULL))
 		goto out;
 
-	switch (csdev->subtype.source_subtype) {
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
-		cpu = source_ops(csdev)->cpu_id(csdev);
-		path = per_cpu(tracer_path, cpu);
-		per_cpu(tracer_path, cpu) = NULL;
-		break;
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
-	case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
-		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;
-		}
-		idr_remove(&path_idr, hash);
-		break;
-	default:
-		/* We can't be here */
-		break;
-	}
-
 	coresight_disable_path(path);
 	coresight_release_path(path);
 

-- 
2.34.1