On Fri, Mar 30, 2018 at 11:15:23AM +0800, Leo Yan wrote:
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@linaro.org
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;
I remember telling you to use free_event_data() and etm_setup_aux(). _Maybe_ it made sense in the previous patchset but in this one it won't work. We need to reflect the current trace context, as such use etm_event_start() and etm_event_stop().
In etm_event_start() call coresight_kdump_sink(cpu, sink) just before source_ops(csdev)->enable(). Similarly call coresight_kdump_sink(cpu, NULL) right after source_ops(csdev)->disable() in etm_event_stop().
Find me on IRC if you want more information on this.
} 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) {
This newline shouldn't be part of this set.
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;
Call coresight_kdump_sink() just before coresight_enable_source(). That way if there is a dump just after coresight_enable_source() is called we get the chance of getting some traces in the dump file.
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);@@ -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);@@ -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