greybus: add operation traces

Define a new gb_operation event class, and define and use trace
events that record when an operation is created, finally destroyed,
and when its active count changes.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/greybus_trace.h

@@ -15,6 +15,7 @@
 #include <linux/tracepoint.h>
 
 struct gb_message;
+struct gb_operation;
 struct gb_host_device;
 
 #define gb_bundle_name(message)						\
@@ -111,6 +112,74 @@ DEFINE_EVENT(gb_message, gb_message_cancel_incoming,
 	TP_ARGS(message)
 );
 
+DECLARE_EVENT_CLASS(gb_operation,
+
+	TP_PROTO(struct gb_operation *operation),
+
+	TP_ARGS(operation),
+
+	TP_STRUCT__entry(
+		__field(u16, cport_id)	/* CPort of HD side of connection */
+		__field(u16, id)	/* Operation ID */
+		__field(u8, type)
+		__field(unsigned long, flags)
+		__field(int, active)
+		__field(int, waiters)
+		__field(int, errno)
+	),
+
+	TP_fast_assign(
+		__entry->cport_id = operation->connection->hd_cport_id;
+		__entry->id = operation->id;
+		__entry->type = operation->type;
+		__entry->flags = operation->flags;
+		__entry->active = operation->active;
+		__entry->waiters = atomic_read(&operation->waiters);
+		__entry->errno = operation->errno;
+	),
+
+	TP_printk("id=%04x type=0x%02x cport_id=%04x flags=0x%lx active=%d waiters=%d errno=%d",
+		  __entry->id, __entry->cport_id, __entry->type, __entry->flags,
+		  __entry->active, __entry->waiters, __entry->errno)
+);
+
+#define DEFINE_OPERATION_EVENT(name)					\
+		DEFINE_EVENT(gb_operation, name,			\
+				TP_PROTO(struct gb_operation *operation), \
+				TP_ARGS(operation))
+
+/*
+ * Occurs after a new operation is created for an outgoing request
+ * has been successfully created.
+ */
+DEFINE_OPERATION_EVENT(gb_operation_create);
+
+/*
+ * Occurs after a new operation has been created for an incoming
+ * request has been successfully created and initialized.
+ */
+DEFINE_OPERATION_EVENT(gb_operation_create_incoming);
+
+/*
+ * Occurs when the last reference to an operation has been dropped,
+ * prior to freeing resources.
+ */
+DEFINE_OPERATION_EVENT(gb_operation_destroy);
+
+/*
+ * Occurs when an operation has been marked active, after updating
+ * its active count.
+ */
+DEFINE_OPERATION_EVENT(gb_operation_get_active);
+
+/*
+ * Occurs when an operation has been marked active, before updating
+ * its active count.
+ */
+DEFINE_OPERATION_EVENT(gb_operation_put_active);
+
+#undef DEFINE_OPERATION_EVENT
+
 DECLARE_EVENT_CLASS(gb_host_device,
 
 	TP_PROTO(struct gb_host_device *hd, u16 intf_cport_id,

drivers/staging/greybus/operation.c

@@ -57,6 +57,8 @@ static int gb_operation_get_active(struct gb_operation *operation)
 	if (operation->active++ == 0)
 		list_add_tail(&operation->links, &connection->operations);
 
+	trace_gb_operation_get_active(operation);
+
 	spin_unlock_irqrestore(&connection->lock, flags);
 
 	return 0;
@@ -69,6 +71,9 @@ static void gb_operation_put_active(struct gb_operation *operation)
 	unsigned long flags;
 
 	spin_lock_irqsave(&connection->lock, flags);
+
+	trace_gb_operation_get_active(operation);
+
 	if (--operation->active == 0) {
 		list_del(&operation->links);
 		if (atomic_read(&operation->waiters))
@@ -536,6 +541,8 @@ gb_operation_create_flags(struct gb_connection *connection,
 				size_t response_size, unsigned long flags,
 				gfp_t gfp)
 {
+	struct gb_operation *operation;
+
 	if (WARN_ON_ONCE(type == GB_REQUEST_TYPE_INVALID))
 		return NULL;
 	if (WARN_ON_ONCE(type & GB_MESSAGE_TYPE_RESPONSE))
@@ -544,9 +551,14 @@ gb_operation_create_flags(struct gb_connection *connection,
 	if (WARN_ON_ONCE(flags & ~GB_OPERATION_FLAG_USER_MASK))
 		flags &= GB_OPERATION_FLAG_USER_MASK;
 
-	return gb_operation_create_common(connection, type,
+	operation = gb_operation_create_common(connection, type,
 						request_size, response_size,
 						flags, gfp);
+	if (operation)
+		trace_gb_operation_create(operation);
+
+	return operation;
+
 }
 EXPORT_SYMBOL_GPL(gb_operation_create_flags);
 
@@ -581,6 +593,7 @@ gb_operation_create_incoming(struct gb_connection *connection, u16 id,
 
 	operation->id = id;
 	memcpy(operation->request->header, data, size);
+	trace_gb_operation_create_incoming(operation);
 
 	return operation;
 }
@@ -603,6 +616,8 @@ static void _gb_operation_destroy(struct kref *kref)
 
 	operation = container_of(kref, struct gb_operation, kref);
 
+	trace_gb_operation_destroy(operation);
+
 	if (operation->response)
 		gb_operation_message_free(operation->response);
 	gb_operation_message_free(operation->request);