OpenZFS restructuring - move linux tracing code to platform directories

Move Linux specific tracing headers and source to platform directories
and update the build system.

Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9290

include/os/linux/zfs/sys/trace_dbgmsg.h

@@ -0,0 +1,75 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+#if defined(_KERNEL)
+#if defined(HAVE_DECLARE_EVENT_CLASS)
+
+/* Do not include this file directly. Please use <sys/trace.h> instead. */
+#ifndef _SYS_TRACE_DBGMSG_INDIRECT
+#error "trace_dbgmsg.h included directly"
+#endif
+
+/*
+ * This file defines tracepoint events for use by the dbgmsg(),
+ * dprintf(), and SET_ERROR() interfaces. These are grouped here because
+ * they all provide a way to store simple messages in the debug log (as
+ * opposed to events used by the DTRACE_PROBE interfaces which typically
+ * dump structured data).
+ *
+ * This header is included inside the trace.h multiple inclusion guard,
+ * and it is guarded above against direct inclusion, so it and need not
+ * be guarded separately.
+ */
+
+/*
+ * Generic support for one argument tracepoints of the form:
+ *
+ * DTRACE_PROBE1(...,
+ *     const char *, ...);
+ */
+/* BEGIN CSTYLED */
+DECLARE_EVENT_CLASS(zfs_dprintf_class,
+	TP_PROTO(const char *msg),
+	TP_ARGS(msg),
+	TP_STRUCT__entry(
+	    __string(msg, msg)
+	),
+	TP_fast_assign(
+	    __assign_str(msg, msg);
+	),
+	TP_printk("%s", __get_str(msg))
+);
+/* END CSTYLED */
+
+/* BEGIN CSTYLED */
+#define	DEFINE_DPRINTF_EVENT(name) \
+DEFINE_EVENT(zfs_dprintf_class, name, \
+	TP_PROTO(const char *msg), \
+	TP_ARGS(msg))
+/* END CSTYLED */
+DEFINE_DPRINTF_EVENT(zfs_zfs__dprintf);
+
+#else
+
+DEFINE_DTRACE_PROBE1(zfs__dprintf);
+
+#endif /* HAVE_DECLARE_EVENT_CLASS */
+#endif /* _KERNEL */