[PATCH v10 4/7] Coresight: Introduce a new struct coresight_path
Jie Gan
quic_jiegan at quicinc.com
Sun Feb 16 17:14:51 PST 2025
On 2/14/2025 7:09 PM, James Clark wrote:
>
>
> On 14/02/2025 1:34 am, Jie Gan wrote:
>>
>>
>> On 2/14/2025 12:00 AM, James Clark wrote:
>>>
>>>
>>> On 07/02/2025 6:42 am, Jie Gan wrote:
>>>> 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 at linaro.org>
>>>> Signed-off-by: James Clark <james.clark at linaro.org>
>>>> Signed-off-by: Jie Gan <quic_jiegan at quicinc.com>
>>>> ---
>>>> 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(-)
>>>>
>>> [...]
>>>> @@ -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-
>>>> >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
>>
>>
>
> Sorry I meant to only keep the !IS_VALID_CS_TRACE_ID() bit. We still
> need to call the new coresight_path_assign_trace_id() otherwise it
> doesn't get assigned to the path. I saw that got removed in v11.
>
>
Sorry for the misunderstanding, I was focused on "nothing has changed
here", lol.
I got your point here.
So the updated codes should be:
...
/* ensure we can allocate a trace ID for this CPU */
trace_id = coresight_path_assign_trace_id(path,
CS_MODE_PERF);
if (!IS_VALID_CS_TRACE_ID(trace_id)) {
cpumask_clear_cpu(cpu, mask);
coresight_release_path(path);
continue;
}
...
Thanks,
Jie
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