Re: [PATCH v3 3/9] coresight: change coresight_trace_id_map's lock type to raw_spinlock_t

[Mike Leach]

On Mon, 16 Dec 2024 at 11:50, Yeoreum Yun <yeoreum.yun@xxxxxxx> wrote:
>
> coresight_trace_id_map->lock can be acquired while coresight devices'
> drvdata_lock.
>
> But the drvdata_lock can be raw_spinlock_t (i.e) coresight-etm4x.
>
> To address this, change type of coresight_trace_id_map->lock to
> raw_spinlock_t
>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
> ---
>  drivers/hwtracing/coresight/coresight-core.c  |  2 +-
>  .../hwtracing/coresight/coresight-trace-id.c  | 22 +++++++++----------
>  include/linux/coresight.h                     |  2 +-
>  3 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index ea38ecf26fcb..cc2d87b2f248 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -1164,7 +1164,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
>
>         if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
>             csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
> -               spin_lock_init(&csdev->perf_sink_id_map.lock);
> +               raw_spin_lock_init(&csdev->perf_sink_id_map.lock);
>                 csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);
>                 if (!csdev->perf_sink_id_map.cpu_map) {
>                         kfree(csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
> index d98e12cb30ec..a6531869e9ec 100644
> --- a/drivers/hwtracing/coresight/coresight-trace-id.c
> +++ b/drivers/hwtracing/coresight/coresight-trace-id.c
> @@ -16,7 +16,7 @@
>  static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);
>  static struct coresight_trace_id_map id_map_default = {
>         .cpu_map = &id_map_default_cpu_ids,
> -       .lock = __SPIN_LOCK_UNLOCKED(id_map_default.lock)
> +       .lock = __RAW_SPIN_LOCK_UNLOCKED(id_map_default.lock)
>  };
>
>  /* #define TRACE_ID_DEBUG 1 */
> @@ -121,11 +121,11 @@ static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map
>         unsigned long flags;
>         int cpu;
>
> -       spin_lock_irqsave(&id_map->lock, flags);
> +       raw_spin_lock_irqsave(&id_map->lock, flags);
>         bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
>         for_each_possible_cpu(cpu)
>                 atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
> -       spin_unlock_irqrestore(&id_map->lock, flags);
> +       raw_spin_unlock_irqrestore(&id_map->lock, flags);
>         DUMP_ID_MAP(id_map);
>  }
>
> @@ -134,7 +134,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
>         unsigned long flags;
>         int id;
>
> -       spin_lock_irqsave(&id_map->lock, flags);
> +       raw_spin_lock_irqsave(&id_map->lock, flags);
>
>         /* check for existing allocation for this CPU */
>         id = _coresight_trace_id_read_cpu_id(cpu, id_map);
> @@ -161,7 +161,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
>         atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);
>
>  get_cpu_id_out_unlock:
> -       spin_unlock_irqrestore(&id_map->lock, flags);
> +       raw_spin_unlock_irqrestore(&id_map->lock, flags);
>
>         DUMP_ID_CPU(cpu, id);
>         DUMP_ID_MAP(id_map);
> @@ -178,12 +178,12 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma
>         if (!id)
>                 return;
>
> -       spin_lock_irqsave(&id_map->lock, flags);
> +       raw_spin_lock_irqsave(&id_map->lock, flags);
>
>         coresight_trace_id_free(id, id_map);
>         atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
>
> -       spin_unlock_irqrestore(&id_map->lock, flags);
> +       raw_spin_unlock_irqrestore(&id_map->lock, flags);
>         DUMP_ID_CPU(cpu, id);
>         DUMP_ID_MAP(id_map);
>  }
> @@ -193,10 +193,10 @@ static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *i
>         unsigned long flags;
>         int id;
>
> -       spin_lock_irqsave(&id_map->lock, flags);
> +       raw_spin_lock_irqsave(&id_map->lock, flags);
>         /* prefer odd IDs for system components to avoid legacy CPU IDS */
>         id = coresight_trace_id_alloc_new_id(id_map, 0, true);
> -       spin_unlock_irqrestore(&id_map->lock, flags);
> +       raw_spin_unlock_irqrestore(&id_map->lock, flags);
>
>         DUMP_ID(id);
>         DUMP_ID_MAP(id_map);
> @@ -207,9 +207,9 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *
>  {
>         unsigned long flags;
>
> -       spin_lock_irqsave(&id_map->lock, flags);
> +       raw_spin_lock_irqsave(&id_map->lock, flags);
>         coresight_trace_id_free(id, id_map);
> -       spin_unlock_irqrestore(&id_map->lock, flags);
> +       raw_spin_unlock_irqrestore(&id_map->lock, flags);
>
>         DUMP_ID(id);
>         DUMP_ID_MAP(id_map);
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index 924b58c343b3..6446ca1f09d8 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -233,7 +233,7 @@ struct coresight_trace_id_map {
>         DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
>         atomic_t __percpu *cpu_map;
>         atomic_t perf_cs_etm_session_active;
> -       spinlock_t lock;
> +       raw_spinlock_t lock;
>  };
>
>  /**
> --
> LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
>

Reviewed-by: Mike Leach <mike.leach@xxxxxxxxxx>


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