On 8/5/2025 7:43 PM, Mike Leach wrote:

Hi

On Thu, 17 Jul 2025 at 13:54, Mao Jinlong quic_jinlmao@quicinc.com wrote:

...

For some coresight components like CTI and TPDM, there could be numerous of them. From the node name, we can only get the type and register address of the component. We can't identify the HW or the system the component belongs to. Add label sysfs node support for showing the intuitive name of the device.

Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com Reviewed-by: Mike Leach mike.leach@linaro.org

---

.../testing/sysfs-bus-coresight-devices-cti | 6 ++ .../sysfs-bus-coresight-devices-dummy-source | 6 ++ .../testing/sysfs-bus-coresight-devices-etb10 | 6 ++ .../testing/sysfs-bus-coresight-devices-etm3x | 6 ++ .../testing/sysfs-bus-coresight-devices-etm4x | 6 ++ .../sysfs-bus-coresight-devices-funnel | 6 ++ .../testing/sysfs-bus-coresight-devices-stm | 6 ++ .../testing/sysfs-bus-coresight-devices-tmc | 6 ++ .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++ .../testing/sysfs-bus-coresight-devices-trbe | 6 ++ drivers/hwtracing/coresight/coresight-sysfs.c | 71 ++++++++++++++++++- 11 files changed, 129 insertions(+), 2 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti index a97b70f588da..55367bbc696f 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti @@ -239,3 +239,9 @@ Date: March 2020 KernelVersion: 5.7 Contact: Mike Leach or Mathieu Poirier Description: (Write) Clear all channel / trigger programming.

+What: /sys/bus/coresight/devices/<cti-name>/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source index 0830661ef656..9a11bd5b15cc 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source @@ -13,3 +13,9 @@ KernelVersion: 6.14 Contact: Mao Jinlong quic_jinlmao@quicinc.com Description: (R) Show the trace ID that will appear in the trace stream coming from this trace entity.

+What: /sys/bus/coresight/devices/dummy_source<N>/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etb10 b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etb10 index 9a383f6a74eb..ff1f89795188 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etb10 +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etb10 @@ -19,6 +19,12 @@ Description: (RW) Disables write access to the Trace RAM by stopping the into the Trace RAM following the trigger event is equal to the value stored in this register+1 (from ARM ETB-TRM).

+What: /sys/bus/coresight/devices/<memory_map>.etb/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device.

• What: /sys/bus/coresight/devices/<memory_map>.etb/mgmt/rdp Date: March 2016 KernelVersion: 4.7

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm3x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm3x index 271b57c571aa..743f26619c69 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm3x +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm3x @@ -251,6 +251,12 @@ KernelVersion: 4.4 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RO) Holds the cpu number this tracer is affined to.

+What: /sys/bus/coresight/devices/<memory_map>.[etm|ptm]/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device.

• What: /sys/bus/coresight/devices/<memory_map>.[etm|ptm]/mgmt/etmccr Date: September 2015 KernelVersion: 4.4

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x index a0425d70d009..e6a584a4b040 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x @@ -329,6 +329,12 @@ Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Access the selected single show PE comparator control register.

+What: /sys/bus/coresight/devices/etm<N>/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device.

• What: /sys/bus/coresight/devices/etm<N>/mgmt/trcoslsr Date: April 2015 KernelVersion: 4.01

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel index d75acda5e1b3..5578fa5f6f02 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel @@ -10,3 +10,9 @@ Date: November 2014 KernelVersion: 3.19 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Defines input port priority order.

+What: /sys/bus/coresight/devices/<memory_map>.funnel/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm index 53e1f4815d64..c3a81978e30b 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm @@ -51,3 +51,9 @@ KernelVersion: 4.7 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Holds the trace ID that will appear in the trace stream coming from this trace entity.

+What: /sys/bus/coresight/devices/<memory_map>.stm/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tmc b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tmc index 339cec3b2f1a..9554f4f453a3 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tmc +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tmc @@ -107,3 +107,9 @@ Contact: Anshuman Khandual anshuman.khandual@arm.com Description: (RW) Current Coresight TMC-ETR buffer mode selected. But user could only provide a mode which is supported for a given ETR device. This file is available only for TMC ETR devices.

+What: /sys/bus/coresight/devices/<memory_map>.tmc/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm index a341b08ae70b..e6d935e83042 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm @@ -272,3 +272,9 @@ KernelVersion 6.15 Contact: Jinlong Mao (QUIC) quic_jinlmao@quicinc.com, Tao Zhang (QUIC) quic_taozha@quicinc.com Description: (RW) Set/Get the enablement of the individual lane.

+What: /sys/bus/coresight/devices/<tpdm-name>/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-trbe b/Documentation/ABI/testing/sysfs-bus-coresight-devices-trbe index ad3bbc6fa751..2a5868ba3d6b 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-trbe +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-trbe @@ -12,3 +12,9 @@ Contact: Anshuman Khandual anshuman.khandual@arm.com Description: (Read) Shows if TRBE updates in the memory are with access and dirty flag updates as well. This value is fetched from the TRBIDR register.

+What: /sys/bus/coresight/devices/trbe<cpu>/label +Date: Jul 2025 +KernelVersion 6.17 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (Read) Show hardware context information of device. diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index feadaf065b53..f7a0c9056854 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -7,6 +7,7 @@ #include <linux/device.h> #include <linux/idr.h> #include <linux/kernel.h> +#include <linux/property.h>

#include "coresight-priv.h" #include "coresight-trace-id.h" @@ -371,17 +372,81 @@ static ssize_t enable_source_store(struct device *dev, } static DEVICE_ATTR_RW(enable_source);

+static ssize_t label_show(struct device *dev,

•           struct device_attribute *attr, char *buf)
  

+{

•   const char *str;
  

•   int ret;
  

•   ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str);
  

•   if (ret == 0)
  

•           return scnprintf(buf, PAGE_SIZE, "%s\n", str);
  

sysfs_emit() here.

I will update it.

...

•   else
  

•           return ret;
  

+} +static DEVICE_ATTR_RO(label);

+static umode_t label_is_visible(struct kobject *kobj,

•                              struct attribute *attr, int n)
  

+{

•   struct device *dev = kobj_to_dev(kobj);
  

•   if (attr == &dev_attr_label.attr) {
  

•           if (fwnode_property_present(dev_fwnode(dev), "label"))
  

•                   return attr->mode;
  

•           else
  

•                   return 0;
  

•   }
  

•   return attr->mode;
  

+}

• static struct attribute *coresight_sink_attrs[] = { &dev_attr_enable_sink.attr,

•   &dev_attr_label.attr,
     NULL,
  

  };

-ATTRIBUTE_GROUPS(coresight_sink);

+static struct attribute_group coresight_sink_group = {

•   .attrs = coresight_sink_attrs,
  

•   .is_visible = label_is_visible,
  

+}; +__ATTRIBUTE_GROUPS(coresight_sink);

static struct attribute *coresight_source_attrs[] = { &dev_attr_enable_source.attr,

•   &dev_attr_label.attr,
     NULL,
  

  };

-ATTRIBUTE_GROUPS(coresight_source);

+static struct attribute_group coresight_source_group = {

•   .attrs = coresight_source_attrs,
  

•   .is_visible = label_is_visible,
  

+}; +__ATTRIBUTE_GROUPS(coresight_source);

+static struct attribute *coresight_link_attrs[] = {

•   &dev_attr_label.attr,
  

•   NULL,
  

+};

+static struct attribute_group coresight_link_group = {

•   .attrs = coresight_link_attrs,
  

•   .is_visible = label_is_visible,
  

+}; +__ATTRIBUTE_GROUPS(coresight_link);

+static struct attribute *coresight_helper_attrs[] = {

•   &dev_attr_label.attr,
  

•   NULL,
  

+};

+static struct attribute_group coresight_helper_group = {

•   .attrs = coresight_helper_attrs,
  

•   .is_visible = label_is_visible,
  

+}; +__ATTRIBUTE_GROUPS(coresight_helper);

const struct device_type coresight_dev_type[] = { [CORESIGHT_DEV_TYPE_SINK] = { @@ -390,6 +455,7 @@ const struct device_type coresight_dev_type[] = { }, [CORESIGHT_DEV_TYPE_LINK] = { .name = "link",

•           .groups = coresight_link_groups,
     },
     [CORESIGHT_DEV_TYPE_LINKSINK] = {
             .name = "linksink",
  

@@ -401,6 +467,7 @@ const struct device_type coresight_dev_type[] = { }, [CORESIGHT_DEV_TYPE_HELPER] = { .name = "helper",

•           .groups = coresight_helper_groups,
     }
  

  }; /* Ensure the enum matches the names and groups */

-- 2.25.1

with the above change

Reviewed-by: Mike Leach mike.leach@linaro.org