On 16/05/2025 5:07 pm, Leo Yan wrote:
Introduce coresight_set_percpu_source() for setting CPU source device. The sources are maintained in a per CPU structure 'csdev_source'.
The coresight_register() function cannot be used for setting CPU source device as it is absent info for CPU ID. So this commit uses the ETM3 and ETM4 drivers to set and clear CPU sources in probing and removal, respectively.
I agree that doing it in coresight_register() would be better and slightly less fragile.
You could add 'cpu' to 'struct coresight_desc' and then do the assignment to 'csdev_source' in coresight_register() if coresight_is_percpu_source() == true.
Signed-off-by: Leo Yan leo.yan@arm.com
drivers/hwtracing/coresight/coresight-core.c | 7 +++++++ drivers/hwtracing/coresight/coresight-etm3x-core.c | 2 ++ drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 ++ drivers/hwtracing/coresight/coresight-priv.h | 1 + 4 files changed, 12 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index fa758cc21827..1503037662f2 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -32,6 +32,7 @@ */ DEFINE_MUTEX(coresight_mutex); static DEFINE_PER_CPU(struct coresight_device *, csdev_sink); +static DEFINE_PER_CPU(struct coresight_device *, csdev_source); /**
- struct coresight_node - elements of a path, from source to sink
@@ -77,6 +78,12 @@ struct coresight_device *coresight_get_percpu_sink(int cpu) } EXPORT_SYMBOL_GPL(coresight_get_percpu_sink); +void coresight_set_percpu_source(int cpu, struct coresight_device *csdev) +{
- per_cpu(csdev_source, cpu) = csdev;
+} +EXPORT_SYMBOL_GPL(coresight_set_percpu_source);
- static struct coresight_device *coresight_get_source(struct coresight_path *path) { struct coresight_device *csdev;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index 1c6204e14422..de62a0bb7faf 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -879,6 +879,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) } etmdrvdata[drvdata->cpu] = drvdata;
- coresight_set_percpu_source(drvdata->cpu, drvdata->csdev);
Doesn't this need to be done before coresight_register()? Once coresight_mutex is unlocked the device can be used. So you could end up with an enabled device hitting the PM notifier with the per-cpu variable still NULL and not disabling the device. Then the state would be messed up.
Probably another reason to put the assignment in coresight_register().
pm_runtime_put(&adev->dev); dev_info(&drvdata->csdev->dev, @@ -902,6 +903,7 @@ static void etm_remove(struct amba_device *adev) { struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
- coresight_set_percpu_source(drvdata->cpu, NULL); etm_perf_symlink(drvdata->csdev, false);
/* diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index b12d59b89a49..fede0be5cd43 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -2203,6 +2203,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg) } etmdrvdata[drvdata->cpu] = drvdata;
- coresight_set_percpu_source(drvdata->cpu, drvdata->csdev);
dev_info(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n", drvdata->cpu, type_name, major, minor); @@ -2402,6 +2403,7 @@ static void etm4_remove_dev(struct etmv4_drvdata *drvdata) cpus_read_unlock(); if (!had_delayed_probe) {
coresight_set_percpu_source(drvdata->cpu, NULL);diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 33e22b1ba043..59f9ec9cc260 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -250,6 +250,7 @@ void coresight_add_helper(struct coresight_device *csdev, void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); struct coresight_device *coresight_get_percpu_sink(int cpu); +void coresight_set_percpu_source(int cpu, struct coresight_device *csdev); void coresight_disable_source(struct coresight_device *csdev, void *data); void coresight_pause_source(struct coresight_device *csdev); int coresight_resume_source(struct coresight_device *csdev);