vfio-ccw: Refactor how the traces are built

Commit 3cd90214b7 ("vfio: ccw: add tracepoints for interesting error
paths") added a quick trace point to determine where a channel program
failed while being processed.  It's a great addition, but adding more
traces to vfio-ccw is more cumbersome than it needs to be.

Let's refactor how this is done, so that additional traces are easier
to add and can exist outside of the FSM if we ever desire.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20191016142040.14132-2-farman@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

drivers/s390/cio/Makefile

@@ -5,7 +5,7 @@
 
 # The following is required for define_trace.h to find ./trace.h
 CFLAGS_trace.o := -I$(src)
-CFLAGS_vfio_ccw_fsm.o := -I$(src)
+CFLAGS_vfio_ccw_trace.o := -I$(src)
 
 obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o \
 	fcx.o itcw.o crw.o ccwreq.o trace.o ioasm.o
@@ -21,5 +21,5 @@ qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o
 obj-$(CONFIG_QDIO) += qdio.o
 
 vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \
-	vfio_ccw_async.o
+	vfio_ccw_async.o vfio_ccw_trace.o
 obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o

drivers/s390/cio/vfio_ccw_cp.h

@@ -15,6 +15,7 @@
 #include <asm/scsw.h>
 
 #include "orb.h"
+#include "vfio_ccw_trace.h"
 
 /*
  * Max length for ccw chain.

drivers/s390/cio/vfio_ccw_fsm.c

@@ -15,9 +15,6 @@
 #include "ioasm.h"
 #include "vfio_ccw_private.h"
 
-#define CREATE_TRACE_POINTS
-#include "vfio_ccw_trace.h"
-
 static int fsm_io_helper(struct vfio_ccw_private *private)
 {
 	struct subchannel *sch;

drivers/s390/cio/vfio_ccw_trace.c

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tracepoint definitions for vfio_ccw
+ *
+ * Copyright IBM Corp. 2019
+ * Author(s): Eric Farman <farman@linux.ibm.com>
+ */
+
+#define CREATE_TRACE_POINTS
+#include "vfio_ccw_trace.h"
+
+EXPORT_TRACEPOINT_SYMBOL(vfio_ccw_io_fctl);

drivers/s390/cio/vfio_ccw_trace.h

@@ -7,6 +7,8 @@
  *            Halil Pasic <pasic@linux.vnet.ibm.com>
  */
 
+#include "cio.h"
+
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM vfio_ccw