[people/ms/u-boot.git] / include / log.h

/*
 * Logging support
 *
 * Copyright (c) 2017 Google, Inc
 * Written by Simon Glass <sjg@chromium.org>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef __LOG_H
#define __LOG_H

#include <dm/uclass-id.h>
#include <linux/list.h>

/** Log levels supported, ranging from most to least important */
enum log_level_t {
	LOGL_EMERG = 0,		/*U-Boot is unstable */
	LOGL_ALERT,		/* Action must be taken immediately */
	LOGL_CRIT,		/* Critical conditions */
	LOGL_ERR,		/* Error that prevents something from working */
	LOGL_WARNING,		/* Warning may prevent optimial operation */
	LOGL_NOTICE,		/* Normal but significant condition, printf() */
	LOGL_INFO,		/* General information message */
	LOGL_DEBUG,		/* Basic debug-level message */
	LOGL_DEBUG_CONTENT,	/* Debug message showing full message content */
	LOGL_DEBUG_IO,		/* Debug message showing hardware I/O access */

	LOGL_COUNT,
	LOGL_NONE,

	LOGL_FIRST = LOGL_EMERG,
	LOGL_MAX = LOGL_DEBUG_IO,
};

/**
 * Log categories supported. Most of these correspond to uclasses (i.e.
 * enum uclass_id) but there are also some more generic categories
 */
enum log_category_t {
	LOGC_FIRST = 0,	/* First part mirrors UCLASS_... */

	LOGC_NONE = UCLASS_COUNT,
	LOGC_ARCH,
	LOGC_BOARD,
	LOGC_CORE,
	LOGC_DM,	/* Core driver-model */
	LOGC_DT,	/* Device-tree */
	LOGL_EFI,	/* EFI implementation */

	LOGC_COUNT,
	LOGC_END,
};

/* Helper to cast a uclass ID to a log category */
static inline int log_uc_cat(enum uclass_id id)
{
	return (enum log_category_t)id;
}

/**
 * _log() - Internal function to emit a new log record
 *
 * @cat: Category of log record (indicating which subsystem generated it)
 * @level: Level of log record (indicating its severity)
 * @file: File name of file where log record was generated
 * @line: Line number in file where log record was generated
 * @func: Function where log record was generated
 * @fmt: printf() format string for log record
 * @...: Optional parameters, according to the format string @fmt
 * @return 0 if log record was emitted, -ve on error
 */
int _log(enum log_category_t cat, enum log_level_t level, const char *file,
	 int line, const char *func, const char *fmt, ...);

/* Define this at the top of a file to add a prefix to debug messages */
#ifndef pr_fmt
#define pr_fmt(fmt) fmt
#endif

/* Use a default category if this file does not supply one */
#ifndef LOG_CATEGORY
#define LOG_CATEGORY LOGC_NONE
#endif

/*
 * This header may be including when CONFIG_LOG is disabled, in which case
 * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
 */
#if CONFIG_IS_ENABLED(LOG)
#define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
#else
#define _LOG_MAX_LEVEL LOGL_INFO
#endif

/* Emit a log record if the level is less that the maximum */
#define log(_cat, _level, _fmt, _args...) ({ \
	int _l = _level; \
	if (_l <= _LOG_MAX_LEVEL) \
		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
		      __func__, \
		      pr_fmt(_fmt), ##_args); \
	})

#ifdef DEBUG
#define _DEBUG	1
#else
#define _DEBUG	0
#endif

#ifdef CONFIG_SPL_BUILD
#define _SPL_BUILD	1
#else
#define _SPL_BUILD	0
#endif

#if !_DEBUG && CONFIG_IS_ENABLED(LOG)

#define debug_cond(cond, fmt, args...)			\
	do {						\
		if (1)					\
			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
	} while (0)

#else /* _DEBUG */

/*
 * Output a debug text when condition "cond" is met. The "cond" should be
 * computed by a preprocessor in the best case, allowing for the best
 * optimization.
 */
#define debug_cond(cond, fmt, args...)			\
	do {						\
		if (cond)				\
			printf(pr_fmt(fmt), ##args);	\
	} while (0)

#endif /* _DEBUG */

/* Show a message if DEBUG is defined in a file */
#define debug(fmt, args...)			\
	debug_cond(_DEBUG, fmt, ##args)

/* Show a message if not in SPL */
#define warn_non_spl(fmt, args...)			\
	debug_cond(!_SPL_BUILD, fmt, ##args)

/*
 * An assertion is run-time check done in debug mode only. If DEBUG is not
 * defined then it is skipped. If DEBUG is defined and the assertion fails,
 * then it calls panic*( which may or may not reset/halt U-Boot (see
 * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
 * before release, and after release it is hoped that they don't matter. But
 * in any case these failing assertions cannot be fixed with a reset (which
 * may just do the same assertion again).
 */
void __assert_fail(const char *assertion, const char *file, unsigned int line,
		   const char *function);
#define assert(x) \
	({ if (!(x) && _DEBUG) \
		__assert_fail(#x, __FILE__, __LINE__, __func__); })

#ifdef CONFIG_LOG_ERROR_RETURN
#define log_ret(_ret) ({ \
	int __ret = (_ret); \
	if (__ret < 0) \
		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
	__ret; \
	})
#else
#define log_ret(_ret) (_ret)
#endif

/**
 * struct log_rec - a single log record
 *
 * Holds information about a single record in the log
 *
 * Members marked as 'not allocated' are stored as pointers and the caller is
 * responsible for making sure that the data pointed to is not overwritten.
 * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
 * system.
 *
 * @cat: Category, representing a uclass or part of U-Boot
 * @level: Severity level, less severe is higher
 * @file: Name of file where the log record was generated (not allocated)
 * @line: Line number where the log record was generated
 * @func: Function where the log record was generated (not allocated)
 * @msg: Log message (allocated)
 */
struct log_rec {
	enum log_category_t cat;
	enum log_level_t level;
	const char *file;
	int line;
	const char *func;
	const char *msg;
};

struct log_device;

/**
 * struct log_driver - a driver which accepts and processes log records
 *
 * @name: Name of driver
 */
struct log_driver {
	const char *name;
	/**
	 * emit() - emit a log record
	 *
	 * Called by the log system to pass a log record to a particular driver
	 * for processing. The filter is checked before calling this function.
	 */
	int (*emit)(struct log_device *ldev, struct log_rec *rec);
};

/**
 * struct log_device - an instance of a log driver
 *
 * Since drivers are set up at build-time we need to have a separate device for
 * the run-time aspects of drivers (currently just a list of filters to apply
 * to records send to this device).
 *
 * @next_filter_num: Seqence number of next filter filter added (0=no filters
 *	yet). This increments with each new filter on the device, but never
 *	decrements
 * @drv: Pointer to driver for this device
 * @filter_head: List of filters for this device
 * @sibling_node: Next device in the list of all devices
 */
struct log_device {
	int next_filter_num;
	struct log_driver *drv;
	struct list_head filter_head;
	struct list_head sibling_node;
};

enum {
	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
};

enum log_filter_flags {
	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
};

/**
 * struct log_filter - criterial to filter out log messages
 *
 * @filter_num: Sequence number of this filter.  This is returned when adding a
 *	new filter, and must be provided when removing a previously added
 *	filter.
 * @flags: Flags for this filter (LOGFF_...)
 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
 *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
 *	can be provided
 * @max_level: Maximum log level to allow
 * @file_list: List of files to allow, separated by comma. If NULL then all
 *	files are permitted
 * @sibling_node: Next filter in the list of filters for this log device
 */
struct log_filter {
	int filter_num;
	int flags;
	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
	enum log_level_t max_level;
	const char *file_list;
	struct list_head sibling_node;
};

#define LOG_DRIVER(_name) \
	ll_entry_declare(struct log_driver, _name, log_driver)

/**
 * log_get_cat_name() - Get the name of a category
 *
 * @cat: Category to look up
 * @return category name (which may be a uclass driver name)
 */
const char *log_get_cat_name(enum log_category_t cat);

/**
 * log_get_cat_by_name() - Look up a category by name
 *
 * @name: Name to look up
 * @return category ID, or LOGC_NONE if not found
 */
enum log_category_t log_get_cat_by_name(const char *name);

/**
 * log_get_level_name() - Get the name of a log level
 *
 * @level: Log level to look up
 * @return log level name (in ALL CAPS)
 */
const char *log_get_level_name(enum log_level_t level);

/**
 * log_get_level_by_name() - Look up a log level by name
 *
 * @name: Name to look up
 * @return log level ID, or LOGL_NONE if not found
 */
enum log_level_t log_get_level_by_name(const char *name);

/* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
enum log_fmt {
	LOGF_CAT	= 0,
	LOGF_LEVEL,
	LOGF_FILE,
	LOGF_LINE,
	LOGF_FUNC,
	LOGF_MSG,

	LOGF_COUNT,
	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
	LOGF_ALL = 0x3f,
};

/* Handle the 'log test' command */
int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);

/**
 * log_add_filter() - Add a new filter to a log device
 *
 * @drv_name: Driver name to add the filter to (since each driver only has a
 *	single device)
 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
 *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
 *	can be provided
 * @max_level: Maximum log level to allow
 * @file_list: List of files to allow, separated by comma. If NULL then all
 *	files are permitted
 * @return the sequence number of the new filter (>=0) if the filter was added,
 *	or a -ve value on error
 */
int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
		   enum log_level_t max_level, const char *file_list);

/**
 * log_remove_filter() - Remove a filter from a log device
 *
 * @drv_name: Driver name to remove the filter from (since each driver only has
 *	a single device)
 * @filter_num: Filter number to remove (as returned by log_add_filter())
 * @return 0 if the filter was removed, -ENOENT if either the driver or the
 *	filter number was not found
 */
int log_remove_filter(const char *drv_name, int filter_num);

#if CONFIG_IS_ENABLED(LOG)
/**
 * log_init() - Set up the log system ready for use
 *
 * @return 0 if OK, -ENOMEM if out of memory
 */
int log_init(void);
#else
static inline int log_init(void)
{
	return 0;
}
#endif

#endif
Commit	Line	Data
0e98b0a6 SG	1	/*
	2	* Logging support
	3	*
	4	* Copyright (c) 2017 Google, Inc
	5	* Written by Simon Glass <sjg@chromium.org>
	6	*
	7	* SPDX-License-Identifier: GPL-2.0+
	8	*/
	9
	10	#ifndef __LOG_H
	11	#define __LOG_H
	12
e9c8d49d SG	13	#include <dm/uclass-id.h>
	14	#include <linux/list.h>
	15
	16	/** Log levels supported, ranging from most to least important */
	17	enum log_level_t {
	18	LOGL_EMERG = 0, /U-Boot is unstable /
	19	LOGL_ALERT, /* Action must be taken immediately */
	20	LOGL_CRIT, /* Critical conditions */
	21	LOGL_ERR, /* Error that prevents something from working */
	22	LOGL_WARNING, /* Warning may prevent optimial operation */
	23	LOGL_NOTICE, /* Normal but significant condition, printf() */
	24	LOGL_INFO, /* General information message */
	25	LOGL_DEBUG, /* Basic debug-level message */
	26	LOGL_DEBUG_CONTENT, /* Debug message showing full message content */
	27	LOGL_DEBUG_IO, /* Debug message showing hardware I/O access */
	28
	29	LOGL_COUNT,
f941c8d7 SG	30	LOGL_NONE,
f941c8d7 SG	31
e9c8d49d	32	LOGL_FIRST = LOGL_EMERG,
f941c8d7	33	LOGL_MAX = LOGL_DEBUG_IO,
e9c8d49d SG	34	};
	35
	36	/**
	37	* Log categories supported. Most of these correspond to uclasses (i.e.
	38	* enum uclass_id) but there are also some more generic categories
	39	*/
	40	enum log_category_t {
	41	LOGC_FIRST = 0, /* First part mirrors UCLASS_... */
	42
	43	LOGC_NONE = UCLASS_COUNT,
	44	LOGC_ARCH,
	45	LOGC_BOARD,
	46	LOGC_CORE,
f941c8d7 SG	47	LOGC_DM, /* Core driver-model */
f941c8d7 SG	48	LOGC_DT, /* Device-tree */
1973b381	49	LOGL_EFI, /* EFI implementation */
e9c8d49d SG	50
	51	LOGC_COUNT,
	52	LOGC_END,
	53	};
	54
	55	/* Helper to cast a uclass ID to a log category */
	56	static inline int log_uc_cat(enum uclass_id id)
	57	{
	58	return (enum log_category_t)id;
	59	}
	60
	61	/**
	62	* _log() - Internal function to emit a new log record
	63	*
	64	* @cat: Category of log record (indicating which subsystem generated it)
	65	* @level: Level of log record (indicating its severity)
	66	* @file: File name of file where log record was generated
	67	* @line: Line number in file where log record was generated
	68	* @func: Function where log record was generated
	69	* @fmt: printf() format string for log record
	70	* @...: Optional parameters, according to the format string @fmt
	71	* @return 0 if log record was emitted, -ve on error
	72	*/
	73	int _log(enum log_category_t cat, enum log_level_t level, const char *file,
	74	int line, const char func, const char fmt, ...);
	75
	76	/* Define this at the top of a file to add a prefix to debug messages */
	77	#ifndef pr_fmt
	78	#define pr_fmt(fmt) fmt
	79	#endif
	80
	81	/* Use a default category if this file does not supply one */
	82	#ifndef LOG_CATEGORY
	83	#define LOG_CATEGORY LOGC_NONE
	84	#endif
	85
	86	/*
	87	* This header may be including when CONFIG_LOG is disabled, in which case
	88	* CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
	89	*/
	90	#if CONFIG_IS_ENABLED(LOG)
	91	#define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
	92	#else
	93	#define _LOG_MAX_LEVEL LOGL_INFO
	94	#endif
	95
	96	/* Emit a log record if the level is less that the maximum */
	97	#define log(_cat, _level, _fmt, _args...) ({ \
	98	int _l = _level; \
	99	if (_l <= _LOG_MAX_LEVEL) \
	100	_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
	101	__func__, \
	102	pr_fmt(_fmt), ##_args); \
	103	})
	104
0e98b0a6 SG	105	#ifdef DEBUG
	106	#define _DEBUG 1
	107	#else
	108	#define _DEBUG 0
	109	#endif
	110
	111	#ifdef CONFIG_SPL_BUILD
	112	#define _SPL_BUILD 1
	113	#else
	114	#define _SPL_BUILD 0
	115	#endif
	116
e9c8d49d SG	117	#if !_DEBUG && CONFIG_IS_ENABLED(LOG)
	118
	119	#define debug_cond(cond, fmt, args...) \
	120	do { \
	121	if (1) \
	122	log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
	123	} while (0)
	124
	125	#else /* _DEBUG */
	126
0e98b0a6 SG	127	/*
	128	* Output a debug text when condition "cond" is met. The "cond" should be
	129	* computed by a preprocessor in the best case, allowing for the best
	130	* optimization.
	131	*/
	132	#define debug_cond(cond, fmt, args...) \
	133	do { \
	134	if (cond) \
	135	printf(pr_fmt(fmt), ##args); \
	136	} while (0)
	137
e9c8d49d SG	138	#endif /* _DEBUG */
e9c8d49d SG	139
0e98b0a6 SG	140	/* Show a message if DEBUG is defined in a file */
	141	#define debug(fmt, args...) \
	142	debug_cond(_DEBUG, fmt, ##args)
	143
	144	/* Show a message if not in SPL */
	145	#define warn_non_spl(fmt, args...) \
	146	debug_cond(!_SPL_BUILD, fmt, ##args)
	147
	148	/*
	149	* An assertion is run-time check done in debug mode only. If DEBUG is not
	150	* defined then it is skipped. If DEBUG is defined and the assertion fails,
	151	* then it calls panic*( which may or may not reset/halt U-Boot (see
	152	* CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
	153	* before release, and after release it is hoped that they don't matter. But
	154	* in any case these failing assertions cannot be fixed with a reset (which
	155	* may just do the same assertion again).
	156	*/
	157	void __assert_fail(const char assertion, const char file, unsigned int line,
	158	const char *function);
	159	#define assert(x) \
	160	({ if (!(x) && _DEBUG) \
	161	__assert_fail(#x, __FILE__, __LINE__, __func__); })
	162
3707c6ee SG	163	#ifdef CONFIG_LOG_ERROR_RETURN
	164	#define log_ret(_ret) ({ \
	165	int __ret = (_ret); \
	166	if (__ret < 0) \
	167	log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
	168	__ret; \
	169	})
	170	#else
	171	#define log_ret(_ret) (_ret)
	172	#endif
	173
e9c8d49d SG	174	/**
	175	* struct log_rec - a single log record
	176	*
	177	* Holds information about a single record in the log
	178	*
	179	* Members marked as 'not allocated' are stored as pointers and the caller is
	180	* responsible for making sure that the data pointed to is not overwritten.
	181	* Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
	182	* system.
	183	*
	184	* @cat: Category, representing a uclass or part of U-Boot
	185	* @level: Severity level, less severe is higher
	186	* @file: Name of file where the log record was generated (not allocated)
	187	* @line: Line number where the log record was generated
	188	* @func: Function where the log record was generated (not allocated)
	189	* @msg: Log message (allocated)
	190	*/
	191	struct log_rec {
	192	enum log_category_t cat;
	193	enum log_level_t level;
	194	const char *file;
	195	int line;
	196	const char *func;
	197	const char *msg;
	198	};
	199
	200	struct log_device;
	201
	202	/**
	203	* struct log_driver - a driver which accepts and processes log records
	204	*
	205	* @name: Name of driver
	206	*/
	207	struct log_driver {
	208	const char *name;
	209	/**
	210	* emit() - emit a log record
	211	*
	212	* Called by the log system to pass a log record to a particular driver
	213	* for processing. The filter is checked before calling this function.
	214	*/
	215	int (emit)(struct log_device ldev, struct log_rec *rec);
	216	};
	217
	218	/**
	219	* struct log_device - an instance of a log driver
	220	*
	221	* Since drivers are set up at build-time we need to have a separate device for
	222	* the run-time aspects of drivers (currently just a list of filters to apply
	223	* to records send to this device).
	224	*
	225	* @next_filter_num: Seqence number of next filter filter added (0=no filters
	226	* yet). This increments with each new filter on the device, but never
	227	* decrements
	228	* @drv: Pointer to driver for this device
	229	* @filter_head: List of filters for this device
	230	* @sibling_node: Next device in the list of all devices
	231	*/
	232	struct log_device {
	233	int next_filter_num;
	234	struct log_driver *drv;
	235	struct list_head filter_head;
	236	struct list_head sibling_node;
	237	};
238
239	enum {
240	LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */
241	};
242
243	enum log_filter_flags {
244	LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */
245	};
246
247	/**
248	* struct log_filter - criterial to filter out log messages
249	*
250	* @filter_num: Sequence number of this filter. This is returned when adding a
251	* new filter, and must be provided when removing a previously added
252	* filter.
253	* @flags: Flags for this filter (LOGFF_...)
254	* @cat_list: List of categories to allow (terminated by LOGC_none). If empty
255	* then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
256	* can be provided
257	* @max_level: Maximum log level to allow
258	* @file_list: List of files to allow, separated by comma. If NULL then all
259	* files are permitted
260	* @sibling_node: Next filter in the list of filters for this log device
261	*/
262	struct log_filter {
263	int filter_num;
264	int flags;
265	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
266	enum log_level_t max_level;
267	const char *file_list;
268	struct list_head sibling_node;
269	};
270
271	#define LOG_DRIVER(_name) \
272	ll_entry_declare(struct log_driver, _name, log_driver)
273
f941c8d7 SG	274	/**
	275	* log_get_cat_name() - Get the name of a category
	276	*
	277	* @cat: Category to look up
	278	* @return category name (which may be a uclass driver name)
	279	*/
	280	const char *log_get_cat_name(enum log_category_t cat);
	281
	282	/**
	283	* log_get_cat_by_name() - Look up a category by name
	284	*
	285	* @name: Name to look up
	286	* @return category ID, or LOGC_NONE if not found
	287	*/
	288	enum log_category_t log_get_cat_by_name(const char *name);
	289
	290	/**
	291	* log_get_level_name() - Get the name of a log level
	292	*
	293	* @level: Log level to look up
	294	* @return log level name (in ALL CAPS)
	295	*/
	296	const char *log_get_level_name(enum log_level_t level);
	297
	298	/**
	299	* log_get_level_by_name() - Look up a log level by name
	300	*
	301	* @name: Name to look up
	302	* @return log level ID, or LOGL_NONE if not found
	303	*/
	304	enum log_level_t log_get_level_by_name(const char *name);
	305
3b73e8d0 SG	306	/* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
	307	enum log_fmt {
	308	LOGF_CAT = 0,
	309	LOGF_LEVEL,
	310	LOGF_FILE,
	311	LOGF_LINE,
	312	LOGF_FUNC,
	313	LOGF_MSG,
	314
	315	LOGF_COUNT,
	316	LOGF_DEFAULT = (1 << LOGF_FUNC) \| (1 << LOGF_MSG),
	317	LOGF_ALL = 0x3f,
	318	};
	319
ef11ed82 SG	320	/* Handle the 'log test' command */
	321	int do_log_test(cmd_tbl_t cmdtp, int flag, int argc, char const argv[]);
	322
e9c8d49d SG	323	/**
	324	* log_add_filter() - Add a new filter to a log device
	325	*
	326	* @drv_name: Driver name to add the filter to (since each driver only has a
	327	* single device)
	328	* @cat_list: List of categories to allow (terminated by LOGC_none). If empty
	329	* then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
	330	* can be provided
	331	* @max_level: Maximum log level to allow
	332	* @file_list: List of files to allow, separated by comma. If NULL then all
	333	* files are permitted
	334	* @return the sequence number of the new filter (>=0) if the filter was added,
	335	* or a -ve value on error
	336	*/
	337	int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
	338	enum log_level_t max_level, const char *file_list);
	339
	340	/**
	341	* log_remove_filter() - Remove a filter from a log device
	342	*
	343	* @drv_name: Driver name to remove the filter from (since each driver only has
	344	* a single device)
	345	* @filter_num: Filter number to remove (as returned by log_add_filter())
	346	* @return 0 if the filter was removed, -ENOENT if either the driver or the
	347	* filter number was not found
	348	*/
	349	int log_remove_filter(const char *drv_name, int filter_num);
	350
	351	#if CONFIG_IS_ENABLED(LOG)
	352	/**
	353	* log_init() - Set up the log system ready for use
	354	*
	355	* @return 0 if OK, -ENOMEM if out of memory
	356	*/
	357	int log_init(void);
	358	#else
	359	static inline int log_init(void)
	360	{
	361	return 0;
	362	}
	363	#endif
	364
0e98b0a6	365	#endif