[PATCH v5 04/14] gtrace: Add functions to create/destroy a trace component path
Mayuresh Chitale
mayuresh.chitale at oss.qualcomm.com
Mon Aug 10 08:22:06 PDT 2026
From: Anup Patel <anup.patel at oss.qualcomm.com>
Trace needs to be configured on a chain of trace components which are
connected to each other. These chain of components is also referred
to as trace component path. Add functions to create/destroy a trace
component path which will be later used by gtrace perf support.
Co-developed-by: Mayuresh Chitale <mayuresh.chitale at oss.qualcomm.com>
Signed-off-by: Mayuresh Chitale <mayuresh.chitale at oss.qualcomm.com>
Signed-off-by: Anup Patel <anup.patel at oss.qualcomm.com>
---
drivers/hwtracing/gtrace/gtrace-core.c | 223 +++++++++++++++++++++++++
include/linux/gtrace.h | 24 +++
2 files changed, 247 insertions(+)
diff --git a/drivers/hwtracing/gtrace/gtrace-core.c b/drivers/hwtracing/gtrace/gtrace-core.c
index 97398f2b7cbb..a89d195ab5b8 100644
--- a/drivers/hwtracing/gtrace/gtrace-core.c
+++ b/drivers/hwtracing/gtrace/gtrace-core.c
@@ -210,6 +210,53 @@ int gtrace_reset_component(struct gtrace_component *comp)
}
EXPORT_SYMBOL_GPL(gtrace_reset_component);
+static int __gtrace_walk_output_components(struct gtrace_component *comp,
+ bool *stop, void *priv,
+ int (*fn)(struct gtrace_component *comp, bool *stop,
+ struct gtrace_connection *stop_conn,
+ void *priv))
+{
+ struct gtrace_connection *conn, *stop_conn = NULL;
+ struct gtrace_platform_data *pdata = comp->pdata;
+ int i, ret;
+
+ for (i = 0; i < pdata->nr_outconns; i++) {
+ conn = pdata->outconns[i];
+ ret = __gtrace_walk_output_components(conn->dest_comp, stop, priv, fn);
+ if (ret)
+ return ret;
+ if (*stop) {
+ stop_conn = conn;
+ break;
+ }
+ }
+
+ ret = fn(comp, stop, stop_conn, priv);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+int gtrace_walk_output_components(struct gtrace_component *comp, void *priv,
+ int (*fn)(struct gtrace_component *comp, bool *stop,
+ struct gtrace_connection *stop_conn,
+ void *priv))
+{
+ bool stop = false;
+ int ret;
+
+ if (!comp || !fn)
+ return -EINVAL;
+
+ mutex_lock(>race_mutex);
+ ret = __gtrace_walk_output_components(comp, &stop, priv, fn);
+ mutex_unlock(>race_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gtrace_walk_output_components);
+
struct gtrace_component *gtrace_cpu_source(unsigned int cpu)
{
if (!cpu_present(cpu))
@@ -414,6 +461,182 @@ void gtrace_unregister_component(struct gtrace_component *comp)
}
EXPORT_SYMBOL_GPL(gtrace_unregister_component);
+struct gtrace_path_node {
+ struct list_head head;
+ struct gtrace_component *comp;
+ struct gtrace_connection *conn;
+};
+
+struct gtrace_component *gtrace_path_source(struct gtrace_path *path)
+{
+ struct gtrace_path_node *node;
+
+ node = list_first_entry(&path->comp_list, struct gtrace_path_node, head);
+ return node->comp;
+}
+EXPORT_SYMBOL_GPL(gtrace_path_source);
+
+struct gtrace_component *gtrace_path_sink(struct gtrace_path *path)
+{
+ struct gtrace_path_node *node;
+
+ node = list_last_entry(&path->comp_list, struct gtrace_path_node, head);
+ return node->comp;
+}
+EXPORT_SYMBOL_GPL(gtrace_path_sink);
+
+static int gtrace_assign_trace_id(struct gtrace_path *path)
+{
+ const struct gtrace_driver *gtdrv;
+ struct gtrace_component *comp;
+ struct gtrace_path_node *node;
+ int trace_id;
+
+ list_for_each_entry(node, &path->comp_list, head) {
+ comp = node->comp;
+ gtdrv = to_gtrace_driver(comp->dev.driver);
+
+ if (!gtdrv->get_trace_id)
+ continue;
+
+ trace_id = gtdrv->get_trace_id(comp, path->mode);
+ if (trace_id > 0) {
+ path->trace_id = trace_id;
+ return 0;
+ } else if (trace_id < 0) {
+ return trace_id;
+ }
+ }
+
+ return 0;
+}
+
+static void gtrace_unassign_trace_id(struct gtrace_path *path)
+{
+ const struct gtrace_driver *gtdrv;
+ struct gtrace_component *comp;
+ struct gtrace_path_node *node;
+
+ list_for_each_entry(node, &path->comp_list, head) {
+ comp = node->comp;
+ gtdrv = to_gtrace_driver(comp->dev.driver);
+
+ if (!gtdrv->put_trace_id)
+ continue;
+
+ gtdrv->put_trace_id(comp, path->mode, path->trace_id);
+ }
+}
+
+static bool gtrace_path_ready(struct gtrace_path *path)
+{
+ struct gtrace_path_node *node;
+
+ list_for_each_entry(node, &path->comp_list, head) {
+ if (!node->comp->ready)
+ return false;
+ }
+
+ return true;
+}
+
+struct build_path_walk_priv {
+ struct gtrace_path *path;
+ struct gtrace_component *sink;
+};
+
+static int build_path_walk_fn(struct gtrace_component *comp, bool *stop,
+ struct gtrace_connection *stop_conn,
+ void *priv)
+{
+ struct build_path_walk_priv *ppriv = priv;
+ struct gtrace_path *path = ppriv->path;
+ struct gtrace_path_node *node;
+
+ if ((!ppriv->sink && gtrace_is_sink(comp->pdata)) ||
+ (ppriv->sink && ppriv->sink == comp))
+ *stop = true;
+
+ if (*stop) {
+ node = kzalloc_obj(*node);
+ if (!node)
+ return -ENOMEM;
+ INIT_LIST_HEAD(&node->head);
+ gtrace_get_component(comp);
+ node->comp = comp;
+ node->conn = stop_conn;
+ list_add(&node->head, &path->comp_list);
+ }
+
+ return 0;
+}
+
+static void gtrace_release_path_nodes(struct gtrace_path *path)
+{
+ struct gtrace_path_node *node, *node1;
+
+ list_for_each_entry_safe(node, node1, &path->comp_list, head) {
+ list_del(&node->head);
+ gtrace_put_component(node->comp);
+ kfree(node);
+ }
+}
+
+struct gtrace_path *gtrace_create_path(struct gtrace_component *source,
+ struct gtrace_component *sink,
+ enum gtrace_component_mode mode)
+{
+ struct build_path_walk_priv priv;
+ struct gtrace_path *path;
+ int ret = 0;
+
+ if (!source || mode >= GTRACE_COMPONENT_MODE_MAX) {
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ path = kzalloc(sizeof(*path), GFP_KERNEL);
+ if (!path) {
+ ret = -ENOMEM;
+ goto err_out;
+ }
+ INIT_LIST_HEAD(&path->comp_list);
+ path->mode = mode;
+ path->trace_id = GTRACE_INVALID_TRACE_ID;
+
+ priv.path = path;
+ priv.sink = sink;
+ ret = gtrace_walk_output_components(source, &priv, build_path_walk_fn);
+ if (ret < 0)
+ goto err_release_path_nodes;
+
+ if (!gtrace_path_ready(path)) {
+ ret = -EOPNOTSUPP;
+ goto err_release_path_nodes;
+ }
+
+ ret = gtrace_assign_trace_id(path);
+ if (ret < 0)
+ goto err_release_path_nodes;
+
+ return path;
+
+err_release_path_nodes:
+ gtrace_release_path_nodes(path);
+ kfree(path);
+err_out:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(gtrace_create_path);
+
+void gtrace_destroy_path(struct gtrace_path *path)
+{
+ gtrace_unassign_trace_id(path);
+ gtrace_release_path_nodes(path);
+ kfree(path);
+}
+EXPORT_SYMBOL_GPL(gtrace_destroy_path);
+
int __gtrace_register_driver(struct module *owner, struct gtrace_driver *gtdrv)
{
gtdrv->driver.owner = owner;
diff --git a/include/linux/gtrace.h b/include/linux/gtrace.h
index e8ca2bd46e67..b74d4b83b141 100644
--- a/include/linux/gtrace.h
+++ b/include/linux/gtrace.h
@@ -224,6 +224,10 @@ int gtrace_enable_component(struct gtrace_component *comp);
int gtrace_disable_component(struct gtrace_component *comp);
int gtrace_reset_component(struct gtrace_component *comp);
+int gtrace_walk_output_components(struct gtrace_component *comp, void *priv,
+ int (*fn)(struct gtrace_component *comp, bool *stop,
+ struct gtrace_connection *stop_conn,
+ void *priv));
struct gtrace_component *gtrace_cpu_source(unsigned int cpu);
struct gtrace_component *gtrace_register_component(struct gtrace_component_id *id,
@@ -231,6 +235,26 @@ struct gtrace_component *gtrace_register_component(struct gtrace_component_id *i
struct gtrace_platform_data *pdata);
void gtrace_unregister_component(struct gtrace_component *comp);
+/**
+ * struct gtrace_path - Representation of a trace path from source to sink.
+ * @comp_list: List of trace components in the path.
+ * @mode: Usage mode for trace components.
+ * @trace_id: ID of the trace source (typically hart/CPU id).
+ */
+struct gtrace_path {
+ struct list_head comp_list;
+ enum gtrace_component_mode mode;
+ u32 trace_id;
+#define GTRACE_INVALID_TRACE_ID 0
+};
+
+struct gtrace_component *gtrace_path_source(struct gtrace_path *path);
+struct gtrace_component *gtrace_path_sink(struct gtrace_path *path);
+struct gtrace_path *gtrace_create_path(struct gtrace_component *source,
+ struct gtrace_component *sink,
+ enum gtrace_component_mode mode);
+void gtrace_destroy_path(struct gtrace_path *path);
+
/**
* struct gtrace_driver - Representation of a trace driver.
* @id_table: Table to match components handled by the driver.
--
2.43.0
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