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-rw-r--r--drivers/hwtracing/coresight/coresight-etm-perf.c44
1 files changed, 29 insertions, 15 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 6beb662d230c..afe7e7fc1a93 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -127,11 +127,9 @@ static void free_event_data(struct work_struct *work)
event_data = container_of(work, struct etm_event_data, work);
mask = &event_data->mask;
- /*
- * First deal with the sink configuration. See comment in
- * etm_setup_aux() about why we take the first available path.
- */
- if (event_data->snk_config) {
+
+ /* Free the sink buffers, if there are any */
+ if (event_data->snk_config && !WARN_ON(cpumask_empty(mask))) {
cpu = cpumask_first(mask);
sink = coresight_get_sink(etm_event_cpu_path(event_data, cpu));
if (sink_ops(sink)->free_buffer)
@@ -166,7 +164,7 @@ static void *alloc_event_data(int cpu)
if (cpu != -1)
cpumask_set_cpu(cpu, mask);
else
- cpumask_copy(mask, cpu_online_mask);
+ cpumask_copy(mask, cpu_present_mask);
/*
* Each CPU has a single path between source and destination. As such
@@ -218,19 +216,32 @@ static void *etm_setup_aux(int event_cpu, void **pages,
* on the cmd line. As such the "enable_sink" flag in sysFS is reset.
*/
sink = coresight_get_enabled_sink(true);
- if (!sink)
+ if (!sink || !sink_ops(sink)->alloc_buffer)
goto err;
mask = &event_data->mask;
- /* Setup the path for each CPU in a trace session */
+ /*
+ * Setup the path for each CPU in a trace session. We try to build
+ * trace path for each CPU in the mask. If we don't find an ETM
+ * for the CPU or fail to build a path, we clear the CPU from the
+ * mask and continue with the rest. If ever we try to trace on those
+ * CPUs, we can handle it and fail the session.
+ */
for_each_cpu(cpu, mask) {
struct list_head *path;
struct coresight_device *csdev;
csdev = per_cpu(csdev_src, cpu);
- if (!csdev)
- goto err;
+ /*
+ * If there is no ETM associated with this CPU clear it from
+ * the mask and continue with the rest. If ever we try to trace
+ * on this CPU, we handle it accordingly.
+ */
+ if (!csdev) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
/*
* Building a path doesn't enable it, it simply builds a
@@ -238,17 +249,20 @@ static void *etm_setup_aux(int event_cpu, void **pages,
* referenced later when the path is actually needed.
*/
path = coresight_build_path(csdev, sink);
- if (IS_ERR(path))
- goto err;
+ if (IS_ERR(path)) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
*etm_event_cpu_path_ptr(event_data, cpu) = path;
}
- if (!sink_ops(sink)->alloc_buffer)
+ /* If we don't have any CPUs ready for tracing, abort */
+ cpu = cpumask_first(mask);
+ if (cpu >= nr_cpu_ids)
goto err;
- cpu = cpumask_first(mask);
- /* Get the AUX specific data from the sink buffer */
+ /* Allocate the sink buffer for this session */
event_data->snk_config =
sink_ops(sink)->alloc_buffer(sink, cpu, pages,
nr_pages, overwrite);