[PATCH v4 5/6] coresight: Set and clear sink device handler for kdump node

From: Leo Yan
Date: Thu Mar 29 2018 - 23:16:16 EST


If Coresight path is enabled for specific CPU, the sink device handler
need to be set to kdump node; on the other hand we also need to clear
sink device handler when path is disabled.

This patch sets sink devices handler for kdump node for two separate
Coresight enabling modes: CS_MODE_SYSFS and CS_MODE_PERF; and clear the
handler when Coresight is disabled.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-etm-perf.c | 5 +++++
drivers/hwtracing/coresight/coresight.c | 16 ++++++++++++++--
2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 8a0ad77..f8b159c 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -139,6 +139,8 @@ static void free_event_data(struct work_struct *work)
for_each_cpu(cpu, mask) {
if (!(IS_ERR_OR_NULL(event_data->path[cpu])))
coresight_release_path(event_data->path[cpu]);
+
+ coresight_kdump_sink(cpu, NULL);
}

kfree(event_data->path);
@@ -238,6 +240,9 @@ static void *etm_setup_aux(int event_cpu, void **pages,
event_data->path[cpu] = coresight_build_path(csdev, sink);
if (IS_ERR(event_data->path[cpu]))
goto err;
+
+ if (coresight_kdump_sink(cpu, sink))
+ goto err;
}

if (!sink_ops(sink)->alloc_buffer)
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 389c4ba..483a1f7 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -272,6 +272,7 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
static bool coresight_disable_source(struct coresight_device *csdev)
{
if (atomic_dec_return(csdev->refcnt) == 0) {
+
if (source_ops(csdev)->disable)
source_ops(csdev)->disable(csdev, NULL);
csdev->enable = false;
@@ -612,6 +613,13 @@ int coresight_enable(struct coresight_device *csdev)
if (ret)
goto err_source;

+ cpu = source_ops(csdev)->cpu_id(csdev);
+
+ /* Set sink device handler into kdump node */
+ ret = coresight_kdump_sink(cpu, sink);
+ if (ret)
+ goto err_kdump;
+
switch (subtype) {
case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
/*
@@ -621,7 +629,6 @@ int coresight_enable(struct coresight_device *csdev)
* be a single session per tracer (when working from sysFS)
* a per-cpu variable will do just fine.
*/
- cpu = source_ops(csdev)->cpu_id(csdev);
per_cpu(tracer_path, cpu) = path;
break;
case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
@@ -636,6 +643,9 @@ int coresight_enable(struct coresight_device *csdev)
mutex_unlock(&coresight_mutex);
return ret;

+err_kdump:
+ coresight_disable_source(csdev);
+
err_source:
coresight_disable_path(path);

@@ -659,9 +669,10 @@ void coresight_disable(struct coresight_device *csdev)
if (!csdev->enable || !coresight_disable_source(csdev))
goto out;

+ cpu = source_ops(csdev)->cpu_id(csdev);
+
switch (csdev->subtype.source_subtype) {
case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
- cpu = source_ops(csdev)->cpu_id(csdev);
path = per_cpu(tracer_path, cpu);
per_cpu(tracer_path, cpu) = NULL;
break;
@@ -674,6 +685,7 @@ void coresight_disable(struct coresight_device *csdev)
break;
}

+ coresight_kdump_sink(cpu, NULL);
coresight_disable_path(path);
coresight_release_path(path);

--
2.7.4