Re: [PATCH 11/17] coresight: Expose map argument in trace ID API
From: James Clark
Date: Fri May 17 2024 - 06:09:13 EST
On 01/05/2024 12:31, Mike Leach wrote:
> Hi James,
>
> On Mon, 29 Apr 2024 at 16:25, James Clark <james.clark@xxxxxxx> wrote:
>>
>> The trace ID API is currently hard coded to always use the global map.
>> The functions that take the map as an argument aren't currently public.
>> Make them public so that Perf mode can pass in its own maps. At the
>> moment all usages are still hard coded to use the global map, but now
>> on the caller side.
>>
>> System ID functions are unchanged because they will always use the
>> default map.
>>
>> Signed-off-by: James Clark <james.clark@xxxxxxx>
>> ---
>> .../hwtracing/coresight/coresight-etm-perf.c | 5 +++--
>> .../coresight/coresight-etm3x-core.c | 5 +++--
>> .../coresight/coresight-etm4x-core.c | 5 +++--
>> .../hwtracing/coresight/coresight-trace-id.c | 22 +++++++------------
>> .../hwtracing/coresight/coresight-trace-id.h | 9 +++++---
>> 5 files changed, 23 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> index c0c60e6a1703..4afb9d29f355 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> @@ -232,7 +232,7 @@ static void free_event_data(struct work_struct *work)
>> if (!(IS_ERR_OR_NULL(*ppath)))
>> coresight_release_path(*ppath);
>> *ppath = NULL;
>> - coresight_trace_id_put_cpu_id(cpu);
>> + coresight_trace_id_put_cpu_id(cpu, coresight_trace_id_map_default());
>> }
>>
>> /* mark perf event as done for trace id allocator */
>> @@ -401,7 +401,8 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
>> }
>>
>> /* ensure we can allocate a trace ID for this CPU */
>> - trace_id = coresight_trace_id_get_cpu_id(cpu);
>> + trace_id = coresight_trace_id_get_cpu_id(cpu,
>> + coresight_trace_id_map_default());
>> if (!IS_VALID_CS_TRACE_ID(trace_id)) {
>> cpumask_clear_cpu(cpu, mask);
>> coresight_release_path(path);
>> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> index 9d5c1391ffb1..4149e7675ceb 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> @@ -465,7 +465,8 @@ int etm_read_alloc_trace_id(struct etm_drvdata *drvdata)
>> *
>> * trace id function has its own lock
>> */
>> - trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu);
>> + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu,
>> + coresight_trace_id_map_default());
>> if (IS_VALID_CS_TRACE_ID(trace_id))
>> drvdata->traceid = (u8)trace_id;
>> else
>> @@ -477,7 +478,7 @@ int etm_read_alloc_trace_id(struct etm_drvdata *drvdata)
>>
>> void etm_release_trace_id(struct etm_drvdata *drvdata)
>> {
>> - coresight_trace_id_put_cpu_id(drvdata->cpu);
>> + coresight_trace_id_put_cpu_id(drvdata->cpu, coresight_trace_id_map_default());
>> }
>>
>> static int etm_enable_perf(struct coresight_device *csdev,
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index a0bdfabddbc6..f32c8cd7742d 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -241,7 +241,8 @@ int etm4_read_alloc_trace_id(struct etmv4_drvdata *drvdata)
>> * or return the one currently allocated.
>> * The trace id function has its own lock
>> */
>> - trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu);
>> + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu,
>> + coresight_trace_id_map_default());
>> if (IS_VALID_CS_TRACE_ID(trace_id))
>> drvdata->trcid = (u8)trace_id;
>> else
>> @@ -253,7 +254,7 @@ int etm4_read_alloc_trace_id(struct etmv4_drvdata *drvdata)
>>
>> void etm4_release_trace_id(struct etmv4_drvdata *drvdata)
>> {
>> - coresight_trace_id_put_cpu_id(drvdata->cpu);
>> + coresight_trace_id_put_cpu_id(drvdata->cpu, coresight_trace_id_map_default());
>> }
>>
>> struct etm4_enable_arg {
>> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
>> index 19005b5b4dc4..45ddd50d09a6 100644
>> --- a/drivers/hwtracing/coresight/coresight-trace-id.c
>> +++ b/drivers/hwtracing/coresight/coresight-trace-id.c
>> @@ -12,7 +12,7 @@
>>
>> #include "coresight-trace-id.h"
>>
>> -/* Default trace ID map. Used on systems that don't require per sink mappings */
>> +/* Default trace ID map. Used in sysfs mode and for system sources */
>> static struct coresight_trace_id_map id_map_default;
>>
>> /* maintain a record of the mapping of IDs and pending releases per cpu */
>> @@ -152,7 +152,7 @@ static void coresight_trace_id_release_all_pending(void)
>> DUMP_ID_MAP(id_map);
>> }
>>
>> -static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
>> +int coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
>> {
>> unsigned long flags;
>> int id;
>> @@ -195,8 +195,9 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_
>> DUMP_ID_MAP(id_map);
>> return id;
>> }
>> +EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id);
>>
>> -static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
>> +void coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
>> {
>> unsigned long flags;
>> int id;
>> @@ -222,6 +223,7 @@ static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id
>> DUMP_ID_CPU(cpu, id);
>> DUMP_ID_MAP(id_map);
>> }
>> +EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);
>>
>> static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map)
>> {
>> @@ -250,19 +252,11 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *
>> DUMP_ID_MAP(id_map);
>> }
>>
>> -/* API functions */
>> -
>
> Rather than remove the existing default trace ID functions, simply add
> a few new ones...
>
> e.g. given the existing...
>
> void coresight_trace_id_put_cpu_id(int cpu)
> {
> coresight_trace_id_map_put_cpu_id(cpu, &id_map_default);
> }
> EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);
>
> add:-
>
> void coresight_trace_id_put_cpu_id_map(int cpu, struct
> coresight_trace_id_map *id_map)
> {
> coresight_trace_id_map_put_cpu_id(cpu, id_map);
> }
> EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id_map);
>
> This avoids a whole lot of churn in exposing the default map to
> external functions, putting it in there and then removing it later.
> When any location that was using coresight_trace_id_put_cpu_id() needs
> to supply its own map, change the function name at that point to
> coresight_trace_id_put_cpu_id_map()
>
> Mike
>
>
Yeah I was on the fence about this one when writing it, but I agree I
can make this change.
James