coresight: adding sink parameter to function coresight_build_path()

Up to now function coresight_build_path() was counting on a sink to
have been selected (from sysFS) prior to being called.  This patch
adds a string argument so that a sink matching the argument can be
selected.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index f4174f36c5a095be2ed18c2528f59f4372127b76..f8c7a8733b23e72b1ed58e59094fb061cacc2829 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -184,7 +184,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
                 * list of devices from source to sink that can be
                 * referenced later when the path is actually needed.
                 */
-               event_data->path[cpu] = coresight_build_path(csdev);
+               event_data->path[cpu] = coresight_build_path(csdev, NULL);
                if (!event_data->path[cpu])
                        goto err;
        }

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index ad975c58080d28b0a43034ff2938825262951322..3cb574b3cdd95f4c309da34f17453b3032cbc646 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -94,7 +94,8 @@ static inline void CS_UNLOCK(void __iomem *addr)
 void coresight_disable_path(struct list_head *path);
 int coresight_enable_path(struct list_head *path, u32 mode);
 struct coresight_device *coresight_get_sink(struct list_head *path);
-struct list_head *coresight_build_path(struct coresight_device *csdev);
+struct list_head *coresight_build_path(struct coresight_device *csdev,
+                                      const char *sink);
 void coresight_release_path(struct list_head *path);
 
 #ifdef CONFIG_CORESIGHT_SOURCE_ETM3X

diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index d08d1ab9bba5d7e1c0772d48b6d43802057e323d..508532b3fcac74f2d6dc5593fc5d20fb7944d8f7 100644 (file)
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -371,31 +371,42 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 /**
  * _coresight_build_path - recursively build a path from a @csdev to a sink.
  * @csdev:     The device to start from.
+ * @sink:      The name of the sink this path should connect with.
  * @path:      The list to add devices to.
  *
- * The tree of Coresight device is traversed until an activated sink is
- * found.  From there the sink is added to the list along with all the
- * devices that led to that point - the end result is a list from source
- * to sink. In that list the source is the first device and the sink the
- * last one.
+ * The tree of Coresight device is traversed until an activated sink or
+ * the one specified by @sink is found.
+ * From there the sink is added to the list along with all the devices that
+ * led to that point - the end result is a list from source to sink. In that
+ * list the source is the first device and the sink the last one.
  */
 static int _coresight_build_path(struct coresight_device *csdev,
-                                struct list_head *path)
+                                const char *sink, struct list_head *path)
 {
        int i;
        bool found = false;
        struct coresight_node *node;
 
-       /* An activated sink has been found.  Enqueue the element */
-       if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-            csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && csdev->activated)
-               goto out;
+       /*
+        * First see if we are dealing with a sink.  If we have one check if
+        * it was selected via sysFS or the perf cmd line.
+        */
+       if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+           csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+               /* Activated via perf cmd line */
+               if (sink && !strcmp(dev_name(&csdev->dev), sink))
+                       goto out;
+               /* Activatred via sysFS */
+               if (csdev->activated)
+                       goto out;
+       }
 
        /* Not a sink - recursively explore each port found on this element */
        for (i = 0; i < csdev->nr_outport; i++) {
                struct coresight_device *child_dev = csdev->conns[i].child_dev;
 
-               if (child_dev && _coresight_build_path(child_dev, path) == 0) {
+               if (child_dev &&
+                   _coresight_build_path(child_dev, sink, path) == 0) {
                        found = true;
                        break;
                }
@@ -422,7 +433,8 @@ out:
        return 0;
 }
 
-struct list_head *coresight_build_path(struct coresight_device *csdev)
+struct list_head *coresight_build_path(struct coresight_device *csdev,
+                                      const char *sink)
 {
        struct list_head *path;
        int rc;
@@ -433,7 +445,7 @@ struct list_head *coresight_build_path(struct coresight_device *csdev)
 
        INIT_LIST_HEAD(path);
 
-       rc = _coresight_build_path(csdev, path);
+       rc = _coresight_build_path(csdev, sink, path);
        if (rc) {
                kfree(path);
                return ERR_PTR(rc);
@@ -508,7 +520,7 @@ int coresight_enable(struct coresight_device *csdev)
        if (csdev->enable)
                goto out;
 
-       path = coresight_build_path(csdev);
+       path = coresight_build_path(csdev, NULL);
        if (IS_ERR(path)) {
                pr_err("building path(s) failed\n");
                ret = PTR_ERR(path);