xref: /openbmc/u-boot/include/log.h (revision 44093a15)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Logging support
4  *
5  * Copyright (c) 2017 Google, Inc
6  * Written by Simon Glass <sjg@chromium.org>
7  */
8 
9 #ifndef __LOG_H
10 #define __LOG_H
11 
12 #include <dm/uclass-id.h>
13 #include <linux/list.h>
14 
15 /** Log levels supported, ranging from most to least important */
16 enum log_level_t {
17 	LOGL_EMERG = 0,		/*U-Boot is unstable */
18 	LOGL_ALERT,		/* Action must be taken immediately */
19 	LOGL_CRIT,		/* Critical conditions */
20 	LOGL_ERR,		/* Error that prevents something from working */
21 	LOGL_WARNING,		/* Warning may prevent optimial operation */
22 	LOGL_NOTICE,		/* Normal but significant condition, printf() */
23 	LOGL_INFO,		/* General information message */
24 	LOGL_DEBUG,		/* Basic debug-level message */
25 	LOGL_DEBUG_CONTENT,	/* Debug message showing full message content */
26 	LOGL_DEBUG_IO,		/* Debug message showing hardware I/O access */
27 
28 	LOGL_COUNT,
29 	LOGL_NONE,
30 
31 	LOGL_FIRST = LOGL_EMERG,
32 	LOGL_MAX = LOGL_DEBUG_IO,
33 };
34 
35 /**
36  * Log categories supported. Most of these correspond to uclasses (i.e.
37  * enum uclass_id) but there are also some more generic categories
38  */
39 enum log_category_t {
40 	LOGC_FIRST = 0,	/* First part mirrors UCLASS_... */
41 
42 	LOGC_NONE = UCLASS_COUNT,	/* First number is after all uclasses */
43 	LOGC_ARCH,	/* Related to arch-specific code */
44 	LOGC_BOARD,	/* Related to board-specific code */
45 	LOGC_CORE,	/* Related to core features (non-driver-model) */
46 	LOGC_DM,	/* Core driver-model */
47 	LOGC_DT,	/* Device-tree */
48 	LOGC_EFI,	/* EFI implementation */
49 	LOGC_ALLOC,	/* Memory allocation */
50 
51 	LOGC_COUNT,	/* Number of log categories */
52 	LOGC_END,	/* Sentinel value for a list of log categories */
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 #define log_err(_fmt...)	log(LOG_CATEGORY, LOGL_ERR, ##_fmt)
93 #define log_warning(_fmt...)	log(LOG_CATEGORY, LOGL_WARNING, ##_fmt)
94 #define log_notice(_fmt...)	log(LOG_CATEGORY, LOGL_NOTICE, ##_fmt)
95 #define log_info(_fmt...)	log(LOG_CATEGORY, LOGL_INFO, ##_fmt)
96 #define log_debug(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG, ##_fmt)
97 #define log_content(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG_CONTENT, ##_fmt)
98 #define log_io(_fmt...)		log(LOG_CATEGORY, LOGL_DEBUG_IO, ##_fmt)
99 #else
100 #define _LOG_MAX_LEVEL LOGL_INFO
101 #define log_err(_fmt...)
102 #define log_warning(_fmt...)
103 #define log_notice(_fmt...)
104 #define log_info(_fmt...)
105 #define log_debug(_fmt...)
106 #define log_content(_fmt...)
107 #define log_io(_fmt...)
108 #endif
109 
110 /* Emit a log record if the level is less that the maximum */
111 #define log(_cat, _level, _fmt, _args...) ({ \
112 	int _l = _level; \
113 	if (_l <= _LOG_MAX_LEVEL) \
114 		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
115 		      __func__, \
116 		      pr_fmt(_fmt), ##_args); \
117 	})
118 
119 #ifdef DEBUG
120 #define _DEBUG	1
121 #else
122 #define _DEBUG	0
123 #endif
124 
125 #ifdef CONFIG_SPL_BUILD
126 #define _SPL_BUILD	1
127 #else
128 #define _SPL_BUILD	0
129 #endif
130 
131 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
132 
133 #define debug_cond(cond, fmt, args...)			\
134 	do {						\
135 		if (1)					\
136 			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
137 	} while (0)
138 
139 #else /* _DEBUG */
140 
141 /*
142  * Output a debug text when condition "cond" is met. The "cond" should be
143  * computed by a preprocessor in the best case, allowing for the best
144  * optimization.
145  */
146 #define debug_cond(cond, fmt, args...)			\
147 	do {						\
148 		if (cond)				\
149 			printf(pr_fmt(fmt), ##args);	\
150 	} while (0)
151 
152 #endif /* _DEBUG */
153 
154 /* Show a message if DEBUG is defined in a file */
155 #define debug(fmt, args...)			\
156 	debug_cond(_DEBUG, fmt, ##args)
157 
158 /* Show a message if not in SPL */
159 #define warn_non_spl(fmt, args...)			\
160 	debug_cond(!_SPL_BUILD, fmt, ##args)
161 
162 /*
163  * An assertion is run-time check done in debug mode only. If DEBUG is not
164  * defined then it is skipped. If DEBUG is defined and the assertion fails,
165  * then it calls panic*( which may or may not reset/halt U-Boot (see
166  * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
167  * before release, and after release it is hoped that they don't matter. But
168  * in any case these failing assertions cannot be fixed with a reset (which
169  * may just do the same assertion again).
170  */
171 void __assert_fail(const char *assertion, const char *file, unsigned int line,
172 		   const char *function);
173 #define assert(x) \
174 	({ if (!(x) && _DEBUG) \
175 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
176 
177 #ifdef CONFIG_LOG_ERROR_RETURN
178 #define log_ret(_ret) ({ \
179 	int __ret = (_ret); \
180 	if (__ret < 0) \
181 		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
182 	__ret; \
183 	})
184 #define log_msg_ret(_msg, _ret) ({ \
185 	int __ret = (_ret); \
186 	if (__ret < 0) \
187 		log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
188 		    __ret); \
189 	__ret; \
190 	})
191 #else
192 #define log_ret(_ret) (_ret)
193 #define log_msg_ret(_msg, _ret) (_ret)
194 #endif
195 
196 /**
197  * struct log_rec - a single log record
198  *
199  * Holds information about a single record in the log
200  *
201  * Members marked as 'not allocated' are stored as pointers and the caller is
202  * responsible for making sure that the data pointed to is not overwritten.
203  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
204  * system.
205  *
206  * @cat: Category, representing a uclass or part of U-Boot
207  * @level: Severity level, less severe is higher
208  * @file: Name of file where the log record was generated (not allocated)
209  * @line: Line number where the log record was generated
210  * @func: Function where the log record was generated (not allocated)
211  * @msg: Log message (allocated)
212  */
213 struct log_rec {
214 	enum log_category_t cat;
215 	enum log_level_t level;
216 	const char *file;
217 	int line;
218 	const char *func;
219 	const char *msg;
220 };
221 
222 struct log_device;
223 
224 /**
225  * struct log_driver - a driver which accepts and processes log records
226  *
227  * @name: Name of driver
228  */
229 struct log_driver {
230 	const char *name;
231 	/**
232 	 * emit() - emit a log record
233 	 *
234 	 * Called by the log system to pass a log record to a particular driver
235 	 * for processing. The filter is checked before calling this function.
236 	 */
237 	int (*emit)(struct log_device *ldev, struct log_rec *rec);
238 };
239 
240 /**
241  * struct log_device - an instance of a log driver
242  *
243  * Since drivers are set up at build-time we need to have a separate device for
244  * the run-time aspects of drivers (currently just a list of filters to apply
245  * to records send to this device).
246  *
247  * @next_filter_num: Seqence number of next filter filter added (0=no filters
248  *	yet). This increments with each new filter on the device, but never
249  *	decrements
250  * @drv: Pointer to driver for this device
251  * @filter_head: List of filters for this device
252  * @sibling_node: Next device in the list of all devices
253  */
254 struct log_device {
255 	int next_filter_num;
256 	struct log_driver *drv;
257 	struct list_head filter_head;
258 	struct list_head sibling_node;
259 };
260 
261 enum {
262 	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
263 };
264 
265 enum log_filter_flags {
266 	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
267 };
268 
269 /**
270  * struct log_filter - criterial to filter out log messages
271  *
272  * @filter_num: Sequence number of this filter.  This is returned when adding a
273  *	new filter, and must be provided when removing a previously added
274  *	filter.
275  * @flags: Flags for this filter (LOGFF_...)
276  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
277  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
278  *	can be provided
279  * @max_level: Maximum log level to allow
280  * @file_list: List of files to allow, separated by comma. If NULL then all
281  *	files are permitted
282  * @sibling_node: Next filter in the list of filters for this log device
283  */
284 struct log_filter {
285 	int filter_num;
286 	int flags;
287 	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
288 	enum log_level_t max_level;
289 	const char *file_list;
290 	struct list_head sibling_node;
291 };
292 
293 #define LOG_DRIVER(_name) \
294 	ll_entry_declare(struct log_driver, _name, log_driver)
295 
296 /**
297  * log_get_cat_name() - Get the name of a category
298  *
299  * @cat: Category to look up
300  * @return category name (which may be a uclass driver name) if found, or
301  *	 "<invalid>" if invalid, or "<missing>" if not found
302  */
303 const char *log_get_cat_name(enum log_category_t cat);
304 
305 /**
306  * log_get_cat_by_name() - Look up a category by name
307  *
308  * @name: Name to look up
309  * @return category ID, or LOGC_NONE if not found
310  */
311 enum log_category_t log_get_cat_by_name(const char *name);
312 
313 /**
314  * log_get_level_name() - Get the name of a log level
315  *
316  * @level: Log level to look up
317  * @return log level name (in ALL CAPS)
318  */
319 const char *log_get_level_name(enum log_level_t level);
320 
321 /**
322  * log_get_level_by_name() - Look up a log level by name
323  *
324  * @name: Name to look up
325  * @return log level ID, or LOGL_NONE if not found
326  */
327 enum log_level_t log_get_level_by_name(const char *name);
328 
329 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
330 enum log_fmt {
331 	LOGF_CAT	= 0,
332 	LOGF_LEVEL,
333 	LOGF_FILE,
334 	LOGF_LINE,
335 	LOGF_FUNC,
336 	LOGF_MSG,
337 
338 	LOGF_COUNT,
339 	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
340 	LOGF_ALL = 0x3f,
341 };
342 
343 /* Handle the 'log test' command */
344 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
345 
346 /**
347  * log_add_filter() - Add a new filter to a log device
348  *
349  * @drv_name: Driver name to add the filter to (since each driver only has a
350  *	single device)
351  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
352  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
353  *	can be provided
354  * @max_level: Maximum log level to allow
355  * @file_list: List of files to allow, separated by comma. If NULL then all
356  *	files are permitted
357  * @return the sequence number of the new filter (>=0) if the filter was added,
358  *	or a -ve value on error
359  */
360 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
361 		   enum log_level_t max_level, const char *file_list);
362 
363 /**
364  * log_remove_filter() - Remove a filter from a log device
365  *
366  * @drv_name: Driver name to remove the filter from (since each driver only has
367  *	a single device)
368  * @filter_num: Filter number to remove (as returned by log_add_filter())
369  * @return 0 if the filter was removed, -ENOENT if either the driver or the
370  *	filter number was not found
371  */
372 int log_remove_filter(const char *drv_name, int filter_num);
373 
374 #if CONFIG_IS_ENABLED(LOG)
375 /**
376  * log_init() - Set up the log system ready for use
377  *
378  * @return 0 if OK, -ENOMEM if out of memory
379  */
380 int log_init(void);
381 #else
382 static inline int log_init(void)
383 {
384 	return 0;
385 }
386 #endif
387 
388 #endif
389