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From: Zane Leung <liangzhen@linux.spacemit.com>
To: gregkh@linuxfoundation.org, palmer@dabbelt.com, pjw@kernel.org,
	alexander.shishkin@linux.intel.com, suzuki.poulose@arm.com,
	mchitale@gmail.com, anup@brainfault.org, irogers@google.com
Cc: mike.leach@arm.com, james.clark@linaro.org, leo.yan@arm.com,
	peterz@infradead.org, mingo@redhat.com, namhyung@kernel.org,
	mark.rutland@arm.com, jolsa@kernel.org, adrian.hunter@intel.com,
	alex@ghiti.fr, atish.patra@linux.dev,
	andrew.jones@oss.qualcomm.com, sunilvl@oss.qualcomm.com,
	liangzhen@linux.spacemit.com, zhuangqiubin@linux.spacemit.com,
	coresight@lists.linaro.org, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 09/24] gtrace: Add port-level start/stop driver callbacks
Date: Fri, 23 Oct 2026 11:14:50 +0800	[thread overview]
Message-ID: <20261023031505.2020925-10-liangzhen@linux.spacemit.com> (raw)
In-Reply-To: <20261023031505.2020925-1-liangzhen@linux.spacemit.com>

Add start_port() and stop_port() callbacks to gtrace_driver so
multi-port link components like funnel and replicator can enable a
specific input/output port the first time a path uses it, tracked by
the per-connection src_refcnt/dest_refcnt fields.

Signed-off-by: Zane Leung <liangzhen@linux.spacemit.com>
---
 drivers/hwtracing/gtrace/gtrace-core.c | 66 ++++++++++++++++++++------
 include/linux/gtrace.h                 | 12 +++++
 2 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/drivers/hwtracing/gtrace/gtrace-core.c b/drivers/hwtracing/gtrace/gtrace-core.c
index 3f55d8b7302d..231d06218d8e 100644
--- a/drivers/hwtracing/gtrace/gtrace-core.c
+++ b/drivers/hwtracing/gtrace/gtrace-core.c
@@ -654,7 +654,9 @@ static void gtrace_release_path_nodes(struct gtrace_path *path)
 }
 
 static int __gtrace_comp_start(struct gtrace_component *comp,
-			       struct gtrace_path *path)
+			       struct gtrace_path *path,
+			       struct gtrace_connection *inconn,
+			       struct gtrace_connection *outconn)
 {
 	struct gtrace_comp_priv *cpriv = to_gtrace_comp_priv(comp);
 	const struct gtrace_driver *gtdrv = to_gtrace_driver(comp->dev.driver);
@@ -690,6 +692,12 @@ static int __gtrace_comp_start(struct gtrace_component *comp,
 			cpriv->owner = task_pid_nr(path->event->owner);
 	}
 
+	if (gtdrv->start_port) {
+		ret = gtdrv->start_port(comp, inconn, outconn);
+		if (ret)
+			goto out;
+	}
+
 	cpriv->start_count++;
 out:
 	raw_spin_unlock_irqrestore(&cpriv->lock, flags);
@@ -697,7 +705,9 @@ static int __gtrace_comp_start(struct gtrace_component *comp,
 }
 
 static int __gtrace_comp_stop(struct gtrace_component *comp,
-			      struct gtrace_path *path)
+			      struct gtrace_path *path,
+			      struct gtrace_connection *inconn,
+			      struct gtrace_connection *outconn)
 {
 	struct gtrace_comp_priv *cpriv = to_gtrace_comp_priv(comp);
 	const struct gtrace_driver *gtdrv = to_gtrace_driver(comp->dev.driver);
@@ -715,13 +725,16 @@ static int __gtrace_comp_stop(struct gtrace_component *comp,
 		goto out;
 	}
 
+	if (!gtdrv) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (gtdrv->stop_port)
+		gtdrv->stop_port(comp, inconn, outconn);
+
 	cpriv->start_count--;
 	if (!cpriv->start_count) {
-		if (!gtdrv) {
-			ret = -ENODEV;
-			goto out;
-		}
-
 		if (gtdrv->stop)
 			ret = gtdrv->stop(comp);
 		comp->path = NULL;
@@ -734,19 +747,36 @@ static int __gtrace_comp_stop(struct gtrace_component *comp,
 
 int gtrace_path_start(struct gtrace_path *path)
 {
-	struct gtrace_path_node *node;
+	struct gtrace_path_node *node, *prev;
+	struct gtrace_connection *inconn;
 	int ret = 0;
 
 	list_for_each_entry_reverse(node, &path->comp_list, head) {
-		ret = __gtrace_comp_start(node->comp, path);
+		if (node->comp == gtrace_path_source(path)) {
+			inconn = NULL;
+		} else {
+			prev = list_prev_entry(node, head);
+			inconn = prev->conn;
+		}
+
+		ret = __gtrace_comp_start(node->comp, path, inconn, node->conn);
 		if (ret)
 			break;
 	}
 
 	/* If a component failed to start, stop all the components that were started before it */
-	if (ret)
-		list_for_each_entry_continue(node, &path->comp_list, head)
-			__gtrace_comp_stop(node->comp, path);
+	if (ret) {
+		list_for_each_entry_continue(node, &path->comp_list, head) {
+			if (node->comp == gtrace_path_source(path)) {
+				inconn = NULL;
+			} else {
+				prev = list_prev_entry(node, head);
+				inconn = prev->conn;
+			}
+
+			__gtrace_comp_stop(node->comp, path, inconn, node->conn);
+		}
+	}
 
 	return ret;
 }
@@ -754,11 +784,19 @@ EXPORT_SYMBOL_GPL(gtrace_path_start);
 
 int gtrace_path_stop(struct gtrace_path *path)
 {
-	struct gtrace_path_node *node;
+	struct gtrace_path_node *node, *prev;
+	struct gtrace_connection *inconn;
 	int ret = 0, err;
 
 	list_for_each_entry(node, &path->comp_list, head) {
-		err = __gtrace_comp_stop(node->comp, path);
+		if (node->comp == gtrace_path_source(path)) {
+			inconn = NULL;
+		} else {
+			prev = list_prev_entry(node, head);
+			inconn = prev->conn;
+		}
+
+		err = __gtrace_comp_stop(node->comp, path, inconn, node->conn);
 		if (err && !ret)
 			ret = err;
 	}
diff --git a/include/linux/gtrace.h b/include/linux/gtrace.h
index 4bbe5ac835ec..ee60585ef65c 100644
--- a/include/linux/gtrace.h
+++ b/include/linux/gtrace.h
@@ -55,9 +55,11 @@ enum gtrace_format {
  * @src_port:    A connection's source port number.
  * @src_fwnode:  Source component's fwnode handle.
  * @src_comp:    Source component's pointer.
+ * @src_refcnt:  Number of paths currently using this connection's source port.
  * @dest_port:   A connection's destination port number.
  * @dest_fwnode: Destination component's fwnode handle.
  * @dest_comp:   Destination component's pointer.
+ * @dest_refcnt: Number of paths currently routing data into the destination port.
  */
 struct gtrace_connection {
 	int src_port;
@@ -66,6 +68,8 @@ struct gtrace_connection {
 	struct fwnode_handle *dest_fwnode;
 	struct gtrace_component *src_comp;
 	struct gtrace_component *dest_comp;
+	u32 src_refcnt;
+	u32 dest_refcnt;
 };
 
 struct gtrace_platform_data;
@@ -363,6 +367,8 @@ int gtrace_path_copyto_auxbuf(struct gtrace_path *path,
  *                 via @format (see PERF_AUX_FLAG_PMU_FORMAT_TYPE_MASK).
  * @start:         Callback to start tracing.
  * @stop:          Callback to stop tracing.
+ * @start_port:    Callback to start a specific component port.
+ * @stop_port:     Callback to stop a specific component port.
  * @probe:         Driver probe() function.
  * @remove:        Driver remove() function.
  * @get_trace_id:  Get/allocate a trace ID.
@@ -376,6 +382,12 @@ struct gtrace_driver {
 						 u64 *format);
 	int			(*start)(struct gtrace_component *comp);
 	int			(*stop)(struct gtrace_component *comp);
+	int			(*start_port)(struct gtrace_component *comp,
+					      struct gtrace_connection *inconn,
+					      struct gtrace_connection *outconn);
+	void			(*stop_port)(struct gtrace_component *comp,
+					     struct gtrace_connection *inconn,
+					     struct gtrace_connection *outconn);
 	int			(*probe)(struct gtrace_component *comp);
 	void			(*remove)(struct gtrace_component *comp);
 	int			(*get_trace_id)(struct gtrace_component *comp,
-- 
2.34.1


  parent reply	other threads:[~2026-10-23  3:16 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-23  3:14 [RFC PATCH 00/24] Add Linux RISC-V trace support via the gtrace framework Zane Leung
2026-10-23  3:14 ` [PATCH 01/24] gtrace: Move connection release into component unregister Zane Leung
2026-10-23  3:14 ` [PATCH 02/24] gtrace: Initial implementation of gtrace sysfs framework Zane Leung
2026-10-23  3:14 ` [PATCH 03/24] gtrace: Drop trace format field and helper function Zane Leung
2026-10-23  3:14 ` [PATCH 04/24] gtrace: Add RISC-V trace encoder sysfs support Zane Leung
2026-10-23  3:14 ` [PATCH 05/24] gtrace: Introduce some PMU format attributes Zane Leung
2026-10-23  3:14 ` [PATCH 06/24] gtrace: Replace owner PID with perf_event pointer in gtrace_path Zane Leung
2026-10-23  3:14 ` [PATCH 07/24] gtrace: Parse RISC-V Trace encoder config from perf event Zane Leung
2026-10-23  3:14 ` [PATCH 08/24] gtrace: add perf symlink support for gtrace components Zane Leung
2026-10-23  3:14 ` Zane Leung [this message]
2026-10-23  3:14 ` [PATCH 10/24] gtrace: Add RISC-V trace funnel driver Zane Leung
2026-10-23  3:14 ` [PATCH 11/24] gtrace: Add RISC-V trace timestamp support Zane Leung
2026-10-23  3:14 ` [PATCH 12/24] gtrace: Add RISC-V trace ATB bridge driver Zane Leung
2026-10-23  3:14 ` [PATCH 13/24] gtrace: Add CoreSight platform core APIs Zane Leung
2026-10-23  3:14 ` [PATCH 14/24] gtrace: Add CoreSight funnel driver Zane Leung
2026-10-23  3:14 ` [PATCH 15/24] gtrace: Only copy AUX data from the path sink Zane Leung
2026-10-23  3:14 ` [PATCH 16/24] perf: Flag whether gtrace AUX data carries CoreSight framing Zane Leung
2026-10-23  3:14 ` [PATCH 17/24] gtrace: Unify default sink selection across CPUs in perf setup Zane Leung
2026-10-23  3:14 ` [PATCH 18/24] gtrace: Add sink-specific buffer alloc/free callbacks Zane Leung
2026-10-23  3:15 ` [PATCH 19/24] gtrace: Add setup_sysfs_buf callback to setup sysfs sink buffer Zane Leung
2026-10-23  3:15 ` [PATCH 20/24] gtrace: Add CoreSight TMC driver support Zane Leung
2026-10-23  3:15 ` [PATCH 21/24] perf tools: riscv: making gtrace PMU listable Zane Leung
2026-10-23  3:15 ` [PATCH 22/24] perf tools: Add Nexus RISC-V Trace decoder Zane Leung
2026-10-23  3:15 ` [PATCH 23/24] perf tools: gtrace: Record and parse trace encoder metadata Zane Leung
2026-10-23  3:15 ` [PATCH 24/24] perf tools: gtrace: Add AUX trace decoder and branch sample synthesis Zane Leung

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