Re: [PATCH] coresight: core: Add sysfs node to reset all sources and sinks

Quick correction - you need to look for enable_source / enable_sink files and disable those that are currently '1'

Mike

On Wed, 8 Feb 2023 at 16:16, Mike Leach mike.leach@linaro.org wrote:

Hi

As this is a sysfs only update - would it not be easier to simply use a shell script to iterate through coresight/devices/ looking for disable_source / disable_sink files and setting those accordingly?

See tools/perf/tests/shell/test_arm_coresight.sh for an example of a script that does similar iteration to test coresight in perf

Regards

Mike

On Wed, 8 Feb 2023 at 11:16, Mao Jinlong quic_jinlmao@quicinc.com wrote:

...

Add sysfs node to reset all the sources and sinks. When mltiple sources are enabled, write 1 to reset_source_sink node to disable all sources and sinks.

Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com

drivers/hwtracing/coresight/coresight-core.c | 106 +++++++++++++++++-- 1 file changed, 99 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index d3bf82c0de1d..06741ed2dee7 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -458,6 +458,28 @@ static bool coresight_disable_source(struct coresight_device *csdev) return !csdev->enable; }

+/**

• • coresight_get_source - Get the source from the path
• • @path: The list of devices.
• • Returns the soruce csdev.
• */

+static struct coresight_device *coresight_get_source(struct list_head *path) +{

•   struct coresight_device *csdev;
  

•   if (!path)
  

•           return NULL;
  

•   csdev = list_first_entry(path, struct coresight_node, link)->csdev;
  

•   if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
  

•           return NULL;
  

•   return csdev;
  

+}

/*

• coresight_disable_path_from : Disable components in the given path beyond
• @nd in the list. If @nd is NULL, all the components, except the SOURCE are

@@ -1159,20 +1181,18 @@ int coresight_enable(struct coresight_device *csdev) } EXPORT_SYMBOL_GPL(coresight_enable);

-void coresight_disable(struct coresight_device *csdev) +static void _coresight_disable(struct coresight_device *csdev) { int cpu, ret; struct list_head *path = NULL; u32 hash;

•   mutex_lock(&coresight_mutex);
  

•   ret = coresight_validate_source(csdev, __func__);
    if (ret)
  

•           goto out;
  

•           return;
  
    if (!csdev->enable || !coresight_disable_source(csdev))
  

•           goto out;
  

•           return;
  
    switch (csdev->subtype.source_subtype) {
    case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
  

@@ -1187,7 +1207,7 @@ void coresight_disable(struct coresight_device *csdev) path = idr_find(&path_idr, hash); if (path == NULL) { pr_err("Path is not found for %s\n", dev_name(&csdev->dev));

•                   goto out;
  

•                   return;
            }
            idr_remove(&path_idr, hash);
            break;
  

@@ -1198,8 +1218,12 @@ void coresight_disable(struct coresight_device *csdev)

    coresight_disable_path(path);
    coresight_release_path(path);

+}

-out: +void coresight_disable(struct coresight_device *csdev) +{

•   mutex_lock(&coresight_mutex);
  

•   _coresight_disable(csdev);
    mutex_unlock(&coresight_mutex);
  

} EXPORT_SYMBOL_GPL(coresight_disable); @@ -1761,8 +1785,76 @@ char *coresight_alloc_device_name(struct coresight_dev_list *dict, } EXPORT_SYMBOL_GPL(coresight_alloc_device_name);

+/*

• • Set the sink active status to false.
• */

+static int coresight_reset_sink(struct device *dev, void *data) +{

•   struct coresight_device *csdev = to_coresight_device(dev);
  

•   if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
  

•           csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
  

•           csdev->activated)
  

•           csdev->activated = false;
  

•   return 0;
  

+}

+static void coresight_reset_all_sink(void) +{

•   bus_for_each_dev(&coresight_bustype, NULL, NULL, coresight_reset_sink);
  

+}

+static ssize_t reset_source_sink_store(struct bus_type *bus,

•                                  const char *buf, size_t size)
  

+{

•   int id, cpu, ret = 0;
  

•   unsigned long val;
  

•   struct coresight_device *csdev;
  

•   struct list_head *path = NULL;
  

•   ret = kstrtoul(buf, 10, &val);
  

•   if (ret)
  

•           return ret;
  

•   mutex_lock(&coresight_mutex);
  

•   /* Disable all per cpu sources */
  

•   for_each_present_cpu(cpu) {
  

•           path = per_cpu(tracer_path, cpu);
  

•           if (path) {
  

•                   csdev = coresight_get_source(path);
  

•                   if (!csdev)
  

•                           continue;
  

•           }
  

•           _coresight_disable(csdev);
  

•   }
  

•   /* Disable all sources which aren't associated with CPU */
  

•   idr_for_each_entry (&path_idr, path, id) {
  

•           csdev = coresight_get_source(path);
  

•           if (!csdev)
  

•                   continue;
  

•           _coresight_disable(csdev);
  

•   }
  

•   /* Reset all activated sinks */
  

•   coresight_reset_all_sink();
  

•   mutex_unlock(&coresight_mutex);
  

•   return size;
  

+} +static BUS_ATTR_WO(reset_source_sink);

+static struct attribute *coresight_reset_source_sink_attrs[] = {

•   &bus_attr_reset_source_sink.attr,
  

•   NULL,
  

+}; +ATTRIBUTE_GROUPS(coresight_reset_source_sink);

struct bus_type coresight_bustype = { .name = "coresight",

•   .bus_groups     = coresight_reset_source_sink_groups,
  

};

static int __init coresight_init(void)

2.39.0

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