firewire: core: add support for Linux kernel tracepoints

The Linux Kernel Tracepoints framework is enough useful to trace
packet data inbound to and outbound from core.

This commit adds firewire subsystem to use the framework.

Link: https://lore.kernel.org/r/20240429043218.609398-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/Makefile

@@ -3,7 +3,7 @@
 # Makefile for the Linux IEEE 1394 implementation
 #
 
-firewire-core-y += core-card.o core-cdev.o core-device.o \
+firewire-core-y += core-trace.o core-card.o core-cdev.o core-device.o \
                    core-iso.o core-topology.o core-transaction.o
 firewire-ohci-y += ohci.o
 firewire-sbp2-y += sbp2.o

drivers/firewire/core-trace.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Takashi Sakamoto
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/firewire.h>

include/trace/events/firewire.h

+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Takashi Sakamoto
+
+#define TRACE_SYSTEM	firewire
+
+#if !defined(_FIREWIRE_TRACE_EVENT_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _FIREWIRE_TRACE_EVENT_H
+
+#include <linux/tracepoint.h>
+
+// Placeholder for future use.
+
+#endif // _FIREWIRE_TRACE_EVENT_H
+
+#include <trace/define_trace.h>