Merge branch 'for-5.14/amd-sfh' into for-linus

- support for Renoir and Cezanne SoCs
- support for Ambient Light Sensor
- support for Human Presence Detection sensor

all from Basavaraj Natikar

1 files changed, 106 insertions, 13 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index c1bec2ad3911..6f398377fec9 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -24,7 +24,26 @@
 static struct pmu etm_pmu;
 static bool etm_perf_up;
 
-static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle);
+/*
+ * An ETM context for a running event includes the perf aux handle
+ * and aux_data. For ETM, the aux_data (etm_event_data), consists of
+ * the trace path and the sink configuration. The event data is accessible
+ * via perf_get_aux(handle). However, a sink could "end" a perf output
+ * handle via the IRQ handler. And if the "sink" encounters a failure
+ * to "begin" another session (e.g due to lack of space in the buffer),
+ * the handle will be cleared. Thus, the event_data may not be accessible
+ * from the handle when we get to the etm_event_stop(), which is required
+ * for stopping the trace path. The event_data is guaranteed to stay alive
+ * until "free_aux()", which cannot happen as long as the event is active on
+ * the ETM. Thus the event_data for the session must be part of the ETM context
+ * to make sure we can disable the trace path.
+ */
+struct etm_ctxt {
+	struct perf_output_handle handle;
+	struct etm_event_data *event_data;
+};
+
+static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt);
 static DEFINE_PER_CPU(struct coresight_device *, csdev_src);
 
 /*
@@ -232,6 +251,25 @@ static void etm_free_aux(void *data)
 	schedule_work(&event_data->work);
 }
 
+/*
+ * Check if two given sinks are compatible with each other,
+ * so that they can use the same sink buffers, when an event
+ * moves around.
+ */
+static bool sinks_compatible(struct coresight_device *a,
+			     struct coresight_device *b)
+{
+	if (!a || !b)
+		return false;
+	/*
+	 * If the sinks are of the same subtype and driven
+	 * by the same driver, we can use the same buffer
+	 * on these sinks.
+	 */
+	return (a->subtype.sink_subtype == b->subtype.sink_subtype) &&
+	       (sink_ops(a) == sink_ops(b));
+}
+
 static void *etm_setup_aux(struct perf_event *event, void **pages,
 			   int nr_pages, bool overwrite)
 {
@@ -239,6 +277,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 	int cpu = event->cpu;
 	cpumask_t *mask;
 	struct coresight_device *sink = NULL;
+	struct coresight_device *user_sink = NULL, *last_sink = NULL;
 	struct etm_event_data *event_data = NULL;
 
 	event_data = alloc_event_data(cpu);
@@ -249,7 +288,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 	/* First get the selected sink from user space. */
 	if (event->attr.config2) {
 		id = (u32)event->attr.config2;
-		sink = coresight_get_sink_by_id(id);
+		sink = user_sink = coresight_get_sink_by_id(id);
 	}
 
 	mask = &event_data->mask;
@@ -277,14 +316,33 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 		}
 
 		/*
-		 * No sink provided - look for a default sink for one of the
-		 * devices. At present we only support topology where all CPUs
-		 * use the same sink [N:1], so only need to find one sink. The
-		 * coresight_build_path later will remove any CPU that does not
-		 * attach to the sink, or if we have not found a sink.
+		 * No sink provided - look for a default sink for all the ETMs,
+		 * where this event can be scheduled.
+		 * We allocate the sink specific buffers only once for this
+		 * event. If the ETMs have different default sink devices, we
+		 * can only use a single "type" of sink as the event can carry
+		 * only one sink specific buffer. Thus we have to make sure
+		 * that the sinks are of the same type and driven by the same
+		 * driver, as the one we allocate the buffer for. As such
+		 * we choose the first sink and check if the remaining ETMs
+		 * have a compatible default sink. We don't trace on a CPU
+		 * if the sink is not compatible.
 		 */
-		if (!sink)
+		if (!user_sink) {
+			/* Find the default sink for this ETM */
 			sink = coresight_find_default_sink(csdev);
+			if (!sink) {
+				cpumask_clear_cpu(cpu, mask);
+				continue;
+			}
+
+			/* Check if this sink compatible with the last sink */
+			if (last_sink && !sinks_compatible(last_sink, sink)) {
+				cpumask_clear_cpu(cpu, mask);
+				continue;
+			}
+			last_sink = sink;
+		}
 
 		/*
 		 * Building a path doesn't enable it, it simply builds a
@@ -312,7 +370,12 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 	if (!sink_ops(sink)->alloc_buffer || !sink_ops(sink)->free_buffer)
 		goto err;
 
-	/* Allocate the sink buffer for this session */
+	/*
+	 * Allocate the sink buffer for this session. All the sinks
+	 * where this event can be scheduled are ensured to be of the
+	 * same type. Thus the same sink configuration is used by the
+	 * sinks.
+	 */
 	event_data->snk_config =
 			sink_ops(sink)->alloc_buffer(sink, event, pages,
 						     nr_pages, overwrite);
@@ -332,13 +395,18 @@ static void etm_event_start(struct perf_event *event, int flags)
 {
 	int cpu = smp_processor_id();
 	struct etm_event_data *event_data;
-	struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
+	struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
+	struct perf_output_handle *handle = &ctxt->handle;
 	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
 	struct list_head *path;
 
 	if (!csdev)
 		goto fail;
 
+	/* Have we messed up our tracking ? */
+	if (WARN_ON(ctxt->event_data))
+		goto fail;
+
 	/*
 	 * Deal with the ring buffer API and get a handle on the
 	 * session's information.
@@ -374,6 +442,8 @@ static void etm_event_start(struct perf_event *event, int flags)
 	if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
 		goto fail_disable_path;
 
+	/* Save the event_data for this ETM */
+	ctxt->event_data = event_data;
 out:
 	return;
 
@@ -392,13 +462,30 @@ static void etm_event_stop(struct perf_event *event, int mode)
 	int cpu = smp_processor_id();
 	unsigned long size;
 	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
-	struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
-	struct etm_event_data *event_data = perf_get_aux(handle);
+	struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
+	struct perf_output_handle *handle = &ctxt->handle;
+	struct etm_event_data *event_data;
 	struct list_head *path;
 
+	/*
+	 * If we still have access to the event_data via handle,
+	 * confirm that we haven't messed up the tracking.
+	 */
+	if (handle->event &&
+	    WARN_ON(perf_get_aux(handle) != ctxt->event_data))
+		return;
+
+	event_data = ctxt->event_data;
+	/* Clear the event_data as this ETM is stopping the trace. */
+	ctxt->event_data = NULL;
+
 	if (event->hw.state == PERF_HES_STOPPED)
 		return;
 
+	/* We must have a valid event_data for a running event */
+	if (WARN_ON(!event_data))
+		return;
+
 	if (!csdev)
 		return;
 
@@ -416,7 +503,13 @@ static void etm_event_stop(struct perf_event *event, int mode)
 	/* tell the core */
 	event->hw.state = PERF_HES_STOPPED;
 
-	if (mode & PERF_EF_UPDATE) {
+	/*
+	 * If the handle is not bound to an event anymore
+	 * (e.g, the sink driver was unable to restart the
+	 * handle due to lack of buffer space), we don't
+	 * have to do anything here.
+	 */
+	if (handle->event && (mode & PERF_EF_UPDATE)) {
 		if (WARN_ON_ONCE(handle->event != event))
 			return;