diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 6beb662d230c2..afe7e7fc1a930 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);