Re: [PATCH v15 02/10] Coresight: Add trace_id function to retrieving the trace ID

Jie Gan <quic_jiegan@xxxxxxxxxxx> · Wed, 5 Mar 2025 21:27:17 +0800

On 3/5/2025 7:07 PM, Mike Leach wrote:
Hi,

On Mon, 3 Mar 2025 at 03:30, Jie Gan <quic_jiegan@xxxxxxxxxxx> wrote:

Add 'trace_id' function pointer in coresight_ops. It's responsible for retrieving
the device's trace ID.

Co-developed-by: James Clark <james.clark@xxxxxxxxxx>
Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
Reviewed-by: James Clark <james.clark@xxxxxxxxxx>
Signed-off-by: Jie Gan <quic_jiegan@xxxxxxxxxxx>
---
  drivers/hwtracing/coresight/coresight-core.c  | 30 +++++++++++++++++++
  drivers/hwtracing/coresight/coresight-dummy.c | 13 +++++++-
  .../coresight/coresight-etm3x-core.c          |  1 +
  .../coresight/coresight-etm4x-core.c          |  1 +
  drivers/hwtracing/coresight/coresight-stm.c   | 11 +++++++
  drivers/hwtracing/coresight/coresight-tpda.c  | 11 +++++++
  include/linux/coresight.h                     |  5 ++++
  7 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index ab55e10d4b79..32aa07f4f8c1 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -24,6 +24,7 @@
  #include "coresight-etm-perf.h"
  #include "coresight-priv.h"
  #include "coresight-syscfg.h"
+#include "coresight-trace-id.h"

  /*
   * Mutex used to lock all sysfs enable and disable actions and loading and
@@ -1557,6 +1558,35 @@ void coresight_remove_driver(struct amba_driver *amba_drv,
  }
  EXPORT_SYMBOL_GPL(coresight_remove_driver);

+int coresight_etm_get_trace_id(struct coresight_device *csdev, enum cs_mode mode,
+                              struct coresight_device *sink)
+{
+       int trace_id;
+       int cpu = source_ops(csdev)->cpu_id(csdev);
+

This is a global funciton so need to check that this csdev is a
source,. and does provide a cpu  function before calling it.


Hi Mike,

I put this function here because it's required by etm3x and etm4x. It's 
intended to be called only by ETM devices, which are definitely source 
devices and have a cpu function.

Jie

+       switch (mode) {
+       case CS_MODE_SYSFS:
+               trace_id = coresight_trace_id_get_cpu_id(cpu);
+               break;
+       case CS_MODE_PERF:
+               if (WARN_ON(!sink))
+                       return -EINVAL;
+
+               trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map);
+               break;
+       default:
+               trace_id = -EINVAL;
+               break;
+       }
+
+       if (!IS_VALID_CS_TRACE_ID(trace_id))
+               dev_err(&csdev->dev,
+                       "Failed to allocate trace ID on CPU%d\n", cpu);
+
+       return trace_id;
+}
+EXPORT_SYMBOL_GPL(coresight_etm_get_trace_id);
+
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Pratik Patel <pratikp@xxxxxxxxxxxxxx>");
  MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>");
diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c
index 9be53be8964b..b5692ba358c1 100644
--- a/drivers/hwtracing/coresight/coresight-dummy.c
+++ b/drivers/hwtracing/coresight/coresight-dummy.c
@@ -41,6 +41,16 @@ static void dummy_source_disable(struct coresight_device *csdev,
         dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
  }

+static int dummy_source_trace_id(struct coresight_device *csdev, __maybe_unused enum cs_mode mode,
+                                __maybe_unused struct coresight_device *sink)
+{
+       struct dummy_drvdata *drvdata;
+
+       drvdata = dev_get_drvdata(csdev->dev.parent);
+
+       return drvdata->traceid;
+}
+
  static int dummy_sink_enable(struct coresight_device *csdev, enum cs_mode mode,
                                 void *data)
  {
@@ -62,7 +72,8 @@ static const struct coresight_ops_source dummy_source_ops = {
  };

  static const struct coresight_ops dummy_source_cs_ops = {
-       .source_ops = &dummy_source_ops,
+       .trace_id       = dummy_source_trace_id,
+       .source_ops     = &dummy_source_ops,
  };

  static const struct coresight_ops_sink dummy_sink_ops = {
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index c103f4c70f5d..c1dda4bc4a2f 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -704,6 +704,7 @@ static const struct coresight_ops_source etm_source_ops = {
  };

  static const struct coresight_ops etm_cs_ops = {
+       .trace_id       = coresight_etm_get_trace_id,
         .source_ops     = &etm_source_ops,
  };

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 2c1a60577728..cfd116b87460 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1067,6 +1067,7 @@ static const struct coresight_ops_source etm4_source_ops = {
  };

  static const struct coresight_ops etm4_cs_ops = {
+       .trace_id       = coresight_etm_get_trace_id,
         .source_ops     = &etm4_source_ops,
  };

diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index b581a30a1cd9..aca25b5e3be2 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -281,12 +281,23 @@ static void stm_disable(struct coresight_device *csdev,
         }
  }

+static int stm_trace_id(struct coresight_device *csdev, __maybe_unused enum cs_mode mode,
+                       __maybe_unused struct coresight_device *sink)
+{
+       struct stm_drvdata *drvdata;
+
+       drvdata = dev_get_drvdata(csdev->dev.parent);
+
+       return drvdata->traceid;
+}
+
  static const struct coresight_ops_source stm_source_ops = {
         .enable         = stm_enable,
         .disable        = stm_disable,
  };

  static const struct coresight_ops stm_cs_ops = {
+       .trace_id       = stm_trace_id,
         .source_ops     = &stm_source_ops,
  };

diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 573da8427428..94c2201fc8d3 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -241,12 +241,23 @@ static void tpda_disable(struct coresight_device *csdev,
         dev_dbg(drvdata->dev, "TPDA inport %d disabled\n", in->dest_port);
  }

+static int tpda_trace_id(struct coresight_device *csdev, __maybe_unused enum cs_mode mode,
+                        __maybe_unused struct coresight_device *sink)
+{
+       struct tpda_drvdata *drvdata;
+
+       drvdata = dev_get_drvdata(csdev->dev.parent);
+
+       return drvdata->atid;
+}
+
  static const struct coresight_ops_link tpda_link_ops = {
         .enable         = tpda_enable,
         .disable        = tpda_disable,
  };

  static const struct coresight_ops tpda_cs_ops = {
+       .trace_id       = tpda_trace_id,
         .link_ops       = &tpda_link_ops,
  };

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index c7cd5886c908..ce9a5e71b261 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -335,6 +335,7 @@ enum cs_mode {
         CS_MODE_PERF,
  };

+#define coresight_ops(csdev)   csdev->ops
  #define source_ops(csdev)      csdev->ops->source_ops
  #define sink_ops(csdev)                csdev->ops->sink_ops
  #define link_ops(csdev)                csdev->ops->link_ops
@@ -421,6 +422,8 @@ struct coresight_ops_panic {
  };

  struct coresight_ops {
+       int (*trace_id)(struct coresight_device *csdev, enum cs_mode mode,
+                       struct coresight_device *sink);
         const struct coresight_ops_sink *sink_ops;
         const struct coresight_ops_link *link_ops;
         const struct coresight_ops_source *source_ops;
@@ -709,4 +712,6 @@ int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,

  void coresight_remove_driver(struct amba_driver *amba_drv,
                              struct platform_driver *pdev_drv);
+int coresight_etm_get_trace_id(struct coresight_device *csdev, enum cs_mode mode,
+                              struct coresight_device *sink);
  #endif         /* _LINUX_COREISGHT_H */
--
2.34.1











