[bhnd] Add logging macros to BHND.

There are 5 logging levels:

* ERROR
* WARN
* INFO
* DEBUG
* TRACE

There are 2 logging context:

* with
* without device

DEBUG and TRACE records are printed only if bootverbose.
Logging records are printed with source code line information if acceptable
logging level is DEBUG or TRACE.

Submitted by:	Michael Zhilin <mizhka@gmail.com>
Differential Revision:	https://reviews.freebsd.org/D6247

sys/conf/NOTES

@@ -3061,3 +3061,6 @@ options		EM_MULTIQUEUE # Activate multiqueue features/disable MSI-X
 # zlib I/O stream support
 # This enables support for compressed core dumps.
 options 	GZIO
+
+# BHND(4) drivers
+options		BHND_LOGLEVEL	# Logging threshold level

sys/conf/options

@@ -979,3 +979,6 @@ RANDOM_ENABLE_UMA	opt_global.h
 
 # Intel em(4) driver
 EM_MULTIQUEUE	opt_em.h
+
+# BHND(4) driver
+BHND_LOGLEVEL	opt_global.h

sys/dev/bhnd/bhnd.h

@@ -39,6 +39,7 @@
 
 #include "bhnd_ids.h"
 #include "bhnd_types.h"
+#include "bhnd_debug.h"
 #include "bhnd_bus_if.h"
 
 extern devclass_t bhnd_devclass;

sys/dev/bhnd/bhnd_debug.h

@@ -0,0 +1,192 @@
+/*-
+ * Copyright (c) 2016 Michael Zhilin <mizhka@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *    redistribution must be conditioned upon including a substantially
+ *    similar Disclaimer requirement for further binary redistribution.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGES.
+ */
+
+/* $FreeBSD$ */
+
+/*
+ * This file provides set of macros for logging:
+ *  - BHND_<LEVEL> and
+ *  - BHND_<LEVEL>_DEV
+ * where LEVEL = {ERROR,WARN,INFO,DEBUG}
+ *
+ * BHND_<LEVEL> macros is proxies to printf call and accept same parameters,
+ * for instance:
+ * 	BHND_INFO("register %d has value %d", reg, val);
+ *
+ * BHND_<LEVEL>_DEV macros is proxies to device_printf call and accept
+ * same parameters, for instance:
+ * 	BHND_INFO_DEV(dev, "register %d has value %d", reg, val);
+ *
+ * All macros contains newline char at the end of each call
+ *
+ * ERROR, WARN, INFO messages are printed only if:
+ * 	- log message level is lower than BHND_LOGGING (logging threshold)
+ *
+ * DEBUG, TRACE messages are printed only if:
+ * 	- bootverbose and
+ * 	- log message level is lower than BHND_LOGGING (logging threshold)
+ *
+ * In addition, for debugging purpose log message contains information about
+ * file name and line number if BHND_LOGGING is more than BHND_INFO_LEVEL
+ *
+ * NOTE: macros starting with underscore (_) are private and should be not used
+ *
+ * To override logging (for instance, force tracing), you can use:
+ *  - "options BHND_LOGLEVEL=BHND_TRACE_LEVEL" in kernel configuration
+ *  - "#define	BHND_LOGGING	BHND_TRACE_LEVEL" in source code file
+ *
+ * NOTE: kernel config option doesn't override log level defined on file level,
+ * so try to avoid "#define	BHND_LOGGING"
+ */
+
+#ifndef _BHND_BHND_DEBUG_H_
+#define _BHND_BHND_DEBUG_H_
+
+#include <sys/systm.h>
+
+#include "opt_global.h"
+
+#define	BHND_ERROR_LEVEL	0x00
+#define	BHND_ERROR_MSG		"ERROR"
+#define	BHND_WARN_LEVEL		0x10
+#define	BHND_WARN_MSG		"!WARN"
+#define	BHND_INFO_LEVEL		0x20
+#define	BHND_INFO_MSG		" info"
+#define	BHND_DEBUG_LEVEL	0x30
+#define	BHND_DEBUG_MSG		"debug"
+#define	BHND_TRACE_LEVEL	0x40
+#define	BHND_TRACE_MSG		"trace"
+
+#if !(defined(BHND_LOGGING))
+#if !(defined(BHND_LOGLEVEL))
+/* By default logging will print only INFO+ message*/
+#define	BHND_LOGGING		BHND_INFO_LEVEL
+#else /* defined(BHND_LOGLEVEL) */
+/* Kernel configuration specifies logging level */
+#define	BHND_LOGGING		BHND_LOGLEVEL
+#endif /* !(defined(BHND_LOGLEVEL)) */
+#endif /* !(defined(BHND_LOGGING)) */
+
+#if BHND_LOGGING > BHND_INFO_LEVEL
+#define	_BHND_PRINT(fn, level, fmt, ...)				\
+	do {								\
+		if (level##LEVEL < BHND_DEBUG_LEVEL || bootverbose)	\
+		    fn "[BHND " level##MSG "] %s:%d => " fmt "\n",	\
+			__func__, __LINE__, ## __VA_ARGS__);		\
+	} while(0);
+#else /* BHND_LOGGING <= BHND_INFO_LEVEL */
+#define	_BHND_PRINT(fn, level, fmt, ...)				\
+	do {								\
+		if (level##LEVEL < BHND_DEBUG_LEVEL || bootverbose)	\
+		    fn "bhnd: " fmt "\n", ## __VA_ARGS__);		\
+	} while(0);
+#endif /* BHND_LOGGING > BHND_INFO_LEVEL */
+
+
+#define	_BHND_RAWPRINTFN	printf(
+#define	_BHND_DEVPRINTFN(dev)	device_printf(dev,
+
+#define	_BHND_LOGPRINT(level, fmt, ...) 				\
+	_BHND_PRINT(_BHND_RAWPRINTFN, level, fmt, ## __VA_ARGS__)
+#define	_BHND_DEVPRINT(dev, level, fmt, ...)				\
+	_BHND_PRINT(_BHND_DEVPRINTFN(dev), level, fmt, ## __VA_ARGS__)
+
+#define	BHND_ERROR(fmt, ...)						\
+	_BHND_LOGPRINT(BHND_ERROR_, fmt, ## __VA_ARGS__);
+#define	BHND_ERROR_DEV(dev, fmt, ...)					\
+	_BHND_DEVPRINT(dev, BHND_ERROR_, fmt, ## __VA_ARGS__)
+
+#if BHND_LOGGING >= BHND_WARN_LEVEL
+#define	BHND_WARN(fmt, ...)						\
+	_BHND_LOGPRINT(BHND_WARN_, fmt, ## __VA_ARGS__)
+#define	BHND_WARN_DEV(dev, fmt, ...)					\
+	_BHND_DEVPRINT(dev, BHND_WARN_, fmt, ## __VA_ARGS__)
+
+#if BHND_LOGGING >= BHND_INFO_LEVEL
+#define	BHND_INFO(fmt, ...)						\
+	_BHND_LOGPRINT(BHND_INFO_, fmt, ## __VA_ARGS__)
+#define	BHND_INFO_DEV(dev, fmt, ...)					\
+	_BHND_DEVPRINT(dev, BHND_INFO_, fmt, ## __VA_ARGS__)
+
+#if BHND_LOGGING >= BHND_DEBUG_LEVEL
+#define	BHND_DEBUG(fmt, ...)						\
+	_BHND_LOGPRINT(BHND_DEBUG_, fmt, ## __VA_ARGS__)
+#define	BHND_DEBUG_DEV(dev, fmt, ...)					\
+	_BHND_DEVPRINT(dev, BHND_DEBUG_, fmt, ## __VA_ARGS__)
+
+#if BHND_LOGGING >= BHND_TRACE_LEVEL
+#define	BHND_TRACE(fmt, ...)						\
+	_BHND_LOGPRINT(BHND_TRACE_, fmt, ## __VA_ARGS__)
+#define	BHND_TRACE_DEV(dev, fmt, ...)					\
+	_BHND_DEVPRINT(dev, BHND_TRACE_, fmt, ## __VA_ARGS__)
+
+#endif /* BHND_LOGGING >= BHND_TRACE_LEVEL */
+#endif /* BHND_LOGGING >= BHND_DEBUG_LEVEL */
+#endif /* BHND_LOGGING >= BHND_INFO_LEVEL */
+#endif /* BHND_LOGGING >= BHND_WARN_LEVEL */
+
+/*
+ * Empty defines without device context
+ */
+#if !(defined(BHND_WARN))
+#define	BHND_WARN(fmt, ...);
+#endif
+
+#if !(defined(BHND_INFO))
+#define	BHND_INFO(fmt, ...);
+#endif
+
+#if !(defined(BHND_DEBUG))
+#define	BHND_DEBUG(fmt, ...);
+#endif
+
+#if !(defined(BHND_TRACE))
+#define	BHND_TRACE(fmt, ...);
+#endif
+
+/*
+ * Empty defines with device context
+ */
+#if !(defined(BHND_WARN_DEV))
+#define	BHND_WARN_DEV(dev, fmt, ...);
+#endif
+
+#if !(defined(BHND_INFO_DEV))
+#define	BHND_INFO_DEV(dev, fmt, ...);
+#endif
+
+#if !(defined(BHND_DEBUG_DEV))
+#define	BHND_DEBUG_DEV(dev, fmt, ...);
+#endif
+
+#if !(defined(BHND_TRACE_DEV))
+#define	BHND_TRACE_DEV(dev, fmt, ...);
+#endif
+
+#endif /* _BHND_BHND_DEBUG_H_ */