On 2/14/2025 12:00 AM, James Clark wrote:

On 07/02/2025 6:42 am, Jie Gan wrote:

quoted

Add 'struct coresight_path' to store the data that is needed by
coresight_enable_path/coresight_disable_path. The structure will be
transmitted to any required devices to enable related funcationalities.

The trace_id will be allocated after the path is built. Consequently,
The ETM3x and ETM4x devices will directly read the trace_id from path
which result in etm_read_alloc_trace_id and etm4_read_alloc_trace_id
being deleted.

Co-developed-by: James Clark <james.clark@linaro.org>
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Jie Gan <redacted>
---
  drivers/hwtracing/coresight/coresight-core.c  | 106 +++++++++++++-----
  drivers/hwtracing/coresight/coresight-dummy.c |   5 +-
  .../hwtracing/coresight/coresight-etm-perf.c  |  30 +++--
  .../hwtracing/coresight/coresight-etm-perf.h  |   2 +-
  drivers/hwtracing/coresight/coresight-etm.h   |   1 -
  .../coresight/coresight-etm3x-core.c          |  54 ++-------
  .../coresight/coresight-etm4x-core.c          |  54 ++-------
  drivers/hwtracing/coresight/coresight-etm4x.h |   1 -
  drivers/hwtracing/coresight/coresight-priv.h  |  12 +-
  drivers/hwtracing/coresight/coresight-stm.c   |   3 +-
  drivers/hwtracing/coresight/coresight-sysfs.c |  17 ++-
  drivers/hwtracing/coresight/coresight-tpdm.c  |   3 +-
  include/linux/coresight.h                     |  12 +-
  13 files changed, 143 insertions(+), 157 deletions(-)

[...]

quoted

@@ -352,7 +352,7 @@ static void *etm_setup_aux(struct perf_event 

*event, void **pages,
       * CPUs, we can handle it and fail the session.
       */
      for_each_cpu(cpu, mask) {
-        struct list_head *path;
+        struct coresight_path *path;
          struct coresight_device *csdev;
          csdev = per_cpu(csdev_src, cpu);

@@ -405,15 +405,15 @@ static void *etm_setup_aux(struct perf_event 

*event, void **pages,
              cpumask_clear_cpu(cpu, mask);
              continue;
          }
-
          /* ensure we can allocate a trace ID for this CPU */
-        trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink- 

quoted

perf_sink_id_map);

-        if (!IS_VALID_CS_TRACE_ID(trace_id)) {
+        trace_id = coresight_path_assign_trace_id(path, CS_MODE_PERF);
+
+        /* Can be 0 and valid, ETE doesn't need an ID */
+        if (trace_id < 0) {

Not sure why I wrote it like this, but I think we should leave it as it 
was with !IS_VALID_CS_TRACE_ID(). Even with ETE it calls the trace ID 
allocator, so nothing has changed here.

Sure, Will restore. For ETE or ETM, we dont need traverse the path, just 
directly allocate the trace id based on cpu id.

Jie