Re: [PATCH v12 2/7] Coresight: Add trace_id function to retrieving the trace ID

[Jie Gan <quic_jiegan@quicinc.com>]

On 2/21/2025 1:34 AM, Suzuki K Poulose wrote:
> On 17/02/2025 09:30, Jie Gan wrote:
>> Add 'trace_id' function pointer in ops. It's responsible for
>> retrieving the device's trace ID.
>>
>> Co-developed-by: James Clark <james.clark@linaro.org>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> Reviewed-by: James Clark <james.clark@linaro.org>
>> Signed-off-by: Jie Gan <quic_jiegan@quicinc.com>
> 
> 
> minor nit: Given this is an optional callback, we could as well make
> this a generic ops and avoid checking if it is a link/source etc. We
> anyway check if the op is available before calling it.
> 
> i.e.:
> 
> struct coresight_ops {
> +    int (*trace_id)(struct coresight *csdev,...);
> 
>      ...
> };
>
Hi Suzuki,

Thanks for comment. Looks a good idea because the trace_id is a generic
function for the coresight_deivce, which can simplify our codes.

Will update a new version to acheive the idea.

Thanks,
Jie


> 
> 
> 
>> ---
>>   drivers/hwtracing/coresight/coresight-core.c  | 27 +++++++++++++++++++
>>   drivers/hwtracing/coresight/coresight-dummy.c | 11 ++++++++
>>   .../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                     |  8 ++++++
>>   7 files changed, 70 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/ 
>> hwtracing/coresight/coresight-core.c
>> index 0a9380350fb5..6cad777757f3 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -23,6 +23,7 @@
>>   #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
>> @@ -1515,6 +1516,32 @@ 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);
>> +
>> +    switch (mode) {
>> +    case CS_MODE_SYSFS:
>> +        trace_id = coresight_trace_id_get_cpu_id(cpu);
>> +        break;
>> +    case CS_MODE_PERF:
>> +        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@codeaurora.org>");
>>   MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
>> diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/ 
>> hwtracing/coresight/coresight-dummy.c
>> index 9be53be8964b..c47f0382b943 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)
>>   {
>> @@ -59,6 +69,7 @@ static int dummy_sink_disable(struct 
>> coresight_device *csdev)
>>   static const struct coresight_ops_source dummy_source_ops = {
>>       .enable    = dummy_source_enable,
>>       .disable = dummy_source_disable,
>> +    .trace_id = dummy_source_trace_id,
>>   };
>>   static const struct coresight_ops dummy_source_cs_ops = {
>> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/ 
>> drivers/hwtracing/coresight/coresight-etm3x-core.c
>> index c103f4c70f5d..a38e72ef8e79 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> @@ -701,6 +701,7 @@ static const struct coresight_ops_source 
>> etm_source_ops = {
>>       .cpu_id        = etm_cpu_id,
>>       .enable        = etm_enable,
>>       .disable    = etm_disable,
>> +    .trace_id    = coresight_etm_get_trace_id,
>>   };
>>   static const struct coresight_ops etm_cs_ops = {
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/ 
>> drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index 2c1a60577728..1a993d5380e7 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -1064,6 +1064,7 @@ static const struct coresight_ops_source 
>> etm4_source_ops = {
>>       .cpu_id        = etm4_cpu_id,
>>       .enable        = etm4_enable,
>>       .disable    = etm4_disable,
>> +    .trace_id    = coresight_etm_get_trace_id,
>>   };
>>   static const struct coresight_ops etm4_cs_ops = {
>> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/ 
>> hwtracing/coresight/coresight-stm.c
>> index b581a30a1cd9..64fcfa916562 100644
>> --- a/drivers/hwtracing/coresight/coresight-stm.c
>> +++ b/drivers/hwtracing/coresight/coresight-stm.c
>> @@ -281,9 +281,20 @@ 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,
>> +    .trace_id    = stm_trace_id,
>>   };
>>   static const struct coresight_ops stm_cs_ops = {
>> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/ 
>> hwtracing/coresight/coresight-tpda.c
>> index 189a4abc2561..d80b6427e5a6 100644
>> --- a/drivers/hwtracing/coresight/coresight-tpda.c
>> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
>> @@ -241,9 +241,20 @@ 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,
>> +    .trace_id    = tpda_trace_id,
>>   };
>>   static const struct coresight_ops tpda_cs_ops = {
>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>> index 157c4bd009a1..70407d61262e 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -368,6 +368,7 @@ struct coresight_ops_sink {
>>    * Operations available for links.
>>    * @enable:    enables flow between iport and oport.
>>    * @disable:    disables flow between iport and oport.
>> + * @trace_id:    alloc or read the traceid.
>>    */
>>   struct coresight_ops_link {
>>       int (*enable)(struct coresight_device *csdev,
>> @@ -376,6 +377,8 @@ struct coresight_ops_link {
>>       void (*disable)(struct coresight_device *csdev,
>>               struct coresight_connection *in,
>>               struct coresight_connection *out);
>> +    int (*trace_id)(struct coresight_device *csdev, enum cs_mode mode,
>> +            struct coresight_device *sink);
>>   };
>>   /**
>> @@ -385,6 +388,7 @@ struct coresight_ops_link {
>>    *        is associated to.
>>    * @enable:    enables tracing for a source.
>>    * @disable:    disables tracing for a source.
>> + * @trace_id:    alloc or read the traceid.
>>    */
>>   struct coresight_ops_source {
>>       int (*cpu_id)(struct coresight_device *csdev);
>> @@ -392,6 +396,8 @@ struct coresight_ops_source {
>>                 enum cs_mode mode, struct coresight_trace_id_map 
>> *id_map);
>>       void (*disable)(struct coresight_device *csdev,
>>               struct perf_event *event);
>> +    int (*trace_id)(struct coresight_device *csdev, enum cs_mode mode,
>> +            struct coresight_device *sink);
>>   };
>>   /**
>> @@ -697,4 +703,6 @@ 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 */
>