Re: [PATCH v15 05/10] Coresight: Allocate trace ID after building the path

On 03/03/2025 03:29, Jie Gan wrote:

The trace_id will be stored in coresight_path instead of being declared everywhere and allocated after building the path.

Co-developed-by: James Clark james.clark@linaro.org Signed-off-by: James Clark james.clark@linaro.org Signed-off-by: Jie Gan quic_jiegan@quicinc.com

---

drivers/hwtracing/coresight/coresight-core.c | 44 +++++++++++++++++++ .../hwtracing/coresight/coresight-etm-perf.c | 5 +-- drivers/hwtracing/coresight/coresight-priv.h | 2 + drivers/hwtracing/coresight/coresight-sysfs.c | 4 ++ 4 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index ed0e9368324d..6adc06995d76 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -655,6 +655,50 @@ static void coresight_drop_device(struct coresight_device *csdev) } } +/*

• • coresight device will read their existing or alloc a trace ID, if their trace_id
• • callback is set.
• • Return 0 if the trace_id callback is not set.
• • Return the result of the trace_id callback if it is set. The return value
• • will be the trace_id if successful, and an error number if it fails.
• */

+static int coresight_get_trace_id(struct coresight_device *csdev,

• 		  enum cs_mode mode,
  

• 		  struct coresight_device *sink)
  

+{

• if (coresight_ops(csdev)->trace_id)

• return coresight_ops(csdev)->trace_id(csdev, mode, sink);
  

• return 0;

+}

+/*

• • Call this after creating the path and before enabling it. This leaves
• • the trace ID set on the path, or it remains 0 if it couldn't be assigned.
• */

+void coresight_path_assign_trace_id(struct coresight_path *path,

• 		    enum cs_mode mode)
  

+{

• struct coresight_device *sink = coresight_get_sink(&path->path_list);
• struct coresight_node *nd;
• int trace_id;
• list_for_each_entry(nd, &path->path_list, link) {

• /* Assign a trace ID to the path for the first device that wants to do it */
  

• trace_id = coresight_get_trace_id(nd->csdev, mode, sink);
  

• /*
  

•  * 0 in this context is that it didn't want to assign so keep searching.
  

•  * Non 0 is either success or fail.
  

• */
  

checkpatch complains:

WARNING: Block comments should align the * on each line

#65: FILE: drivers/hwtracing/coresight/coresight-core.c:694:

+ * Non 0 is either success or fail. + */

Please make sure to run the checkpatch on individual patches before submitting in the future. I will fix this up locally for now.

Kind regards Suzuki

• if (trace_id != 0) {
  

• 	path->trace_id = trace_id;
  

• 	return;
  

• }
  

• }

+}

• /**
  • _coresight_build_path - recursively build a path from a @csdev to a sink.
  • @csdev: The device to start from.

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index b0426792f08a..134290ab622e 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -319,7 +319,6 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, { u32 id, cfg_hash; int cpu = event->cpu;

• int trace_id; cpumask_t *mask; struct coresight_device *sink = NULL; struct coresight_device *user_sink = NULL, *last_sink = NULL;

@@ -409,8 +408,8 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, } /* ensure we can allocate a trace ID for this CPU */

• trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map);
  

• if (!IS_VALID_CS_TRACE_ID(trace_id)) {
  

• coresight_path_assign_trace_id(path, CS_MODE_PERF);
  

• if (!IS_VALID_CS_TRACE_ID(path->trace_id)) {
  cpumask_clear_cpu(cpu, mask);
  coresight_release_path(path);
  continue;
  

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 27b7dc348d4a..2bea35bae0d4 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -152,6 +152,8 @@ int coresight_make_links(struct coresight_device *orig, void coresight_remove_links(struct coresight_device *orig, struct coresight_connection *conn); u32 coresight_get_sink_id(struct coresight_device *csdev); +void coresight_path_assign_trace_id(struct coresight_path *path,

• 		   enum cs_mode mode);
  

#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X) extern int etm_readl_cp14(u32 off, unsigned int *val); diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index cb4c39732d26..d03751bf3d8a 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -209,6 +209,10 @@ int coresight_enable_sysfs(struct coresight_device *csdev) goto out; }

• coresight_path_assign_trace_id(path, CS_MODE_SYSFS);
• if (!IS_VALID_CS_TRACE_ID(path->trace_id))

• goto err_path;
  

• ret = coresight_enable_path(&path->path_list, CS_MODE_SYSFS, NULL); if (ret) goto err_path;