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Subject[PATCH v8 01/10] coresight: core: Use IDR for non-cpu bound sources' paths.
Date
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(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index bbf415c252f9..23ab16dd9b5d 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);

--
2.17.1
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