Re: [PATCH 11/17] coresight: Expose map argument in trace ID API

From: Mike Leach
Date: Wed May 01 2024 - 06:32:17 EST


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


> -int coresight_trace_id_get_cpu_id(int cpu)
> -{
> - return coresight_trace_id_map_get_cpu_id(cpu, &id_map_default);
> -}
> -EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id);
> -
> -void coresight_trace_id_put_cpu_id(int cpu)
> +struct coresight_trace_id_map *coresight_trace_id_map_default(void)
> {
> - coresight_trace_id_map_put_cpu_id(cpu, &id_map_default);
> + return &id_map_default;
> }
> -EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);
> +EXPORT_SYMBOL_GPL(coresight_trace_id_map_default);
>
> int coresight_trace_id_read_cpu_id(int cpu)
> {
> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
> index 49438a96fcc6..54b9d8ed903b 100644
> --- a/drivers/hwtracing/coresight/coresight-trace-id.h
> +++ b/drivers/hwtracing/coresight/coresight-trace-id.h
> @@ -42,7 +42,10 @@
> #define IS_VALID_CS_TRACE_ID(id) \
> ((id > CORESIGHT_TRACE_ID_RES_0) && (id < CORESIGHT_TRACE_ID_RES_TOP))
>
> -/* Allocate and release IDs for a single default trace ID map */
> +/**
> + * Get the global map that's used by sysfs
> + */
> +struct coresight_trace_id_map *coresight_trace_id_map_default(void);
>
> /**
> * Read and optionally allocate a CoreSight trace ID and associate with a CPU.
> @@ -57,7 +60,7 @@
> *
> * return: CoreSight trace ID or -EINVAL if allocation impossible.
> */
> -int coresight_trace_id_get_cpu_id(int cpu);
> +int coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map);
>
> /**
> * Release an allocated trace ID associated with the CPU.
> @@ -70,7 +73,7 @@ int coresight_trace_id_get_cpu_id(int cpu);
> *
> * @cpu: The CPU index to release the associated trace ID.
> */
> -void coresight_trace_id_put_cpu_id(int cpu);
> +void coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map);
>
> /**
> * Read the current allocated CoreSight Trace ID value for the CPU.
> --
> 2.34.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK