xref: /openbmc/u-boot/include/log.h (revision c95cafd0)
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 	LOGC_SANDBOX,	/* Related to the sandbox board */
51 
52 	LOGC_COUNT,	/* Number of log categories */
53 	LOGC_END,	/* Sentinel value for a list of log categories */
54 };
55 
56 /* Helper to cast a uclass ID to a log category */
57 static inline int log_uc_cat(enum uclass_id id)
58 {
59 	return (enum log_category_t)id;
60 }
61 
62 /**
63  * _log() - Internal function to emit a new log record
64  *
65  * @cat: Category of log record (indicating which subsystem generated it)
66  * @level: Level of log record (indicating its severity)
67  * @file: File name of file where log record was generated
68  * @line: Line number in file where log record was generated
69  * @func: Function where log record was generated
70  * @fmt: printf() format string for log record
71  * @...: Optional parameters, according to the format string @fmt
72  * @return 0 if log record was emitted, -ve on error
73  */
74 int _log(enum log_category_t cat, enum log_level_t level, const char *file,
75 	 int line, const char *func, const char *fmt, ...);
76 
77 /* Define this at the top of a file to add a prefix to debug messages */
78 #ifndef pr_fmt
79 #define pr_fmt(fmt) fmt
80 #endif
81 
82 /* Use a default category if this file does not supply one */
83 #ifndef LOG_CATEGORY
84 #define LOG_CATEGORY LOGC_NONE
85 #endif
86 
87 /*
88  * This header may be including when CONFIG_LOG is disabled, in which case
89  * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
90  */
91 #if CONFIG_IS_ENABLED(LOG)
92 #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
93 #define log_err(_fmt...)	log(LOG_CATEGORY, LOGL_ERR, ##_fmt)
94 #define log_warning(_fmt...)	log(LOG_CATEGORY, LOGL_WARNING, ##_fmt)
95 #define log_notice(_fmt...)	log(LOG_CATEGORY, LOGL_NOTICE, ##_fmt)
96 #define log_info(_fmt...)	log(LOG_CATEGORY, LOGL_INFO, ##_fmt)
97 #define log_debug(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG, ##_fmt)
98 #define log_content(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG_CONTENT, ##_fmt)
99 #define log_io(_fmt...)		log(LOG_CATEGORY, LOGL_DEBUG_IO, ##_fmt)
100 #else
101 #define _LOG_MAX_LEVEL LOGL_INFO
102 #define log_err(_fmt...)
103 #define log_warning(_fmt...)
104 #define log_notice(_fmt...)
105 #define log_info(_fmt...)
106 #define log_debug(_fmt...)
107 #define log_content(_fmt...)
108 #define log_io(_fmt...)
109 #endif
110 
111 /* Emit a log record if the level is less that the maximum */
112 #define log(_cat, _level, _fmt, _args...) ({ \
113 	int _l = _level; \
114 	if (_l <= _LOG_MAX_LEVEL) \
115 		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
116 		      __func__, \
117 		      pr_fmt(_fmt), ##_args); \
118 	})
119 
120 #ifdef DEBUG
121 #define _DEBUG	1
122 #else
123 #define _DEBUG	0
124 #endif
125 
126 #ifdef CONFIG_SPL_BUILD
127 #define _SPL_BUILD	1
128 #else
129 #define _SPL_BUILD	0
130 #endif
131 
132 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
133 
134 #define debug_cond(cond, fmt, args...)			\
135 	do {						\
136 		if (1)					\
137 			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
138 	} while (0)
139 
140 #else /* _DEBUG */
141 
142 /*
143  * Output a debug text when condition "cond" is met. The "cond" should be
144  * computed by a preprocessor in the best case, allowing for the best
145  * optimization.
146  */
147 #define debug_cond(cond, fmt, args...)			\
148 	do {						\
149 		if (cond)				\
150 			printf(pr_fmt(fmt), ##args);	\
151 	} while (0)
152 
153 #endif /* _DEBUG */
154 
155 /* Show a message if DEBUG is defined in a file */
156 #define debug(fmt, args...)			\
157 	debug_cond(_DEBUG, fmt, ##args)
158 
159 /* Show a message if not in SPL */
160 #define warn_non_spl(fmt, args...)			\
161 	debug_cond(!_SPL_BUILD, fmt, ##args)
162 
163 /*
164  * An assertion is run-time check done in debug mode only. If DEBUG is not
165  * defined then it is skipped. If DEBUG is defined and the assertion fails,
166  * then it calls panic*( which may or may not reset/halt U-Boot (see
167  * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
168  * before release, and after release it is hoped that they don't matter. But
169  * in any case these failing assertions cannot be fixed with a reset (which
170  * may just do the same assertion again).
171  */
172 void __assert_fail(const char *assertion, const char *file, unsigned int line,
173 		   const char *function);
174 #define assert(x) \
175 	({ if (!(x) && _DEBUG) \
176 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
177 
178 #ifdef CONFIG_LOG_ERROR_RETURN
179 #define log_ret(_ret) ({ \
180 	int __ret = (_ret); \
181 	if (__ret < 0) \
182 		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
183 	__ret; \
184 	})
185 #define log_msg_ret(_msg, _ret) ({ \
186 	int __ret = (_ret); \
187 	if (__ret < 0) \
188 		log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
189 		    __ret); \
190 	__ret; \
191 	})
192 #else
193 #define log_ret(_ret) (_ret)
194 #define log_msg_ret(_msg, _ret) (_ret)
195 #endif
196 
197 /**
198  * struct log_rec - a single log record
199  *
200  * Holds information about a single record in the log
201  *
202  * Members marked as 'not allocated' are stored as pointers and the caller is
203  * responsible for making sure that the data pointed to is not overwritten.
204  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
205  * system.
206  *
207  * @cat: Category, representing a uclass or part of U-Boot
208  * @level: Severity level, less severe is higher
209  * @file: Name of file where the log record was generated (not allocated)
210  * @line: Line number where the log record was generated
211  * @func: Function where the log record was generated (not allocated)
212  * @msg: Log message (allocated)
213  */
214 struct log_rec {
215 	enum log_category_t cat;
216 	enum log_level_t level;
217 	const char *file;
218 	int line;
219 	const char *func;
220 	const char *msg;
221 };
222 
223 struct log_device;
224 
225 /**
226  * struct log_driver - a driver which accepts and processes log records
227  *
228  * @name: Name of driver
229  */
230 struct log_driver {
231 	const char *name;
232 	/**
233 	 * emit() - emit a log record
234 	 *
235 	 * Called by the log system to pass a log record to a particular driver
236 	 * for processing. The filter is checked before calling this function.
237 	 */
238 	int (*emit)(struct log_device *ldev, struct log_rec *rec);
239 };
240 
241 /**
242  * struct log_device - an instance of a log driver
243  *
244  * Since drivers are set up at build-time we need to have a separate device for
245  * the run-time aspects of drivers (currently just a list of filters to apply
246  * to records send to this device).
247  *
248  * @next_filter_num: Seqence number of next filter filter added (0=no filters
249  *	yet). This increments with each new filter on the device, but never
250  *	decrements
251  * @drv: Pointer to driver for this device
252  * @filter_head: List of filters for this device
253  * @sibling_node: Next device in the list of all devices
254  */
255 struct log_device {
256 	int next_filter_num;
257 	struct log_driver *drv;
258 	struct list_head filter_head;
259 	struct list_head sibling_node;
260 };
261 
262 enum {
263 	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
264 };
265 
266 enum log_filter_flags {
267 	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
268 };
269 
270 /**
271  * struct log_filter - criterial to filter out log messages
272  *
273  * @filter_num: Sequence number of this filter.  This is returned when adding a
274  *	new filter, and must be provided when removing a previously added
275  *	filter.
276  * @flags: Flags for this filter (LOGFF_...)
277  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
278  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
279  *	can be provided
280  * @max_level: Maximum log level to allow
281  * @file_list: List of files to allow, separated by comma. If NULL then all
282  *	files are permitted
283  * @sibling_node: Next filter in the list of filters for this log device
284  */
285 struct log_filter {
286 	int filter_num;
287 	int flags;
288 	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
289 	enum log_level_t max_level;
290 	const char *file_list;
291 	struct list_head sibling_node;
292 };
293 
294 #define LOG_DRIVER(_name) \
295 	ll_entry_declare(struct log_driver, _name, log_driver)
296 
297 /**
298  * log_get_cat_name() - Get the name of a category
299  *
300  * @cat: Category to look up
301  * @return category name (which may be a uclass driver name) if found, or
302  *	 "<invalid>" if invalid, or "<missing>" if not found
303  */
304 const char *log_get_cat_name(enum log_category_t cat);
305 
306 /**
307  * log_get_cat_by_name() - Look up a category by name
308  *
309  * @name: Name to look up
310  * @return category ID, or LOGC_NONE if not found
311  */
312 enum log_category_t log_get_cat_by_name(const char *name);
313 
314 /**
315  * log_get_level_name() - Get the name of a log level
316  *
317  * @level: Log level to look up
318  * @return log level name (in ALL CAPS)
319  */
320 const char *log_get_level_name(enum log_level_t level);
321 
322 /**
323  * log_get_level_by_name() - Look up a log level by name
324  *
325  * @name: Name to look up
326  * @return log level ID, or LOGL_NONE if not found
327  */
328 enum log_level_t log_get_level_by_name(const char *name);
329 
330 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
331 enum log_fmt {
332 	LOGF_CAT	= 0,
333 	LOGF_LEVEL,
334 	LOGF_FILE,
335 	LOGF_LINE,
336 	LOGF_FUNC,
337 	LOGF_MSG,
338 
339 	LOGF_COUNT,
340 	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
341 	LOGF_ALL = 0x3f,
342 };
343 
344 /* Handle the 'log test' command */
345 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
346 
347 /**
348  * log_add_filter() - Add a new filter to a log device
349  *
350  * @drv_name: Driver name to add the filter to (since each driver only has a
351  *	single device)
352  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
353  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
354  *	can be provided
355  * @max_level: Maximum log level to allow
356  * @file_list: List of files to allow, separated by comma. If NULL then all
357  *	files are permitted
358  * @return the sequence number of the new filter (>=0) if the filter was added,
359  *	or a -ve value on error
360  */
361 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
362 		   enum log_level_t max_level, const char *file_list);
363 
364 /**
365  * log_remove_filter() - Remove a filter from a log device
366  *
367  * @drv_name: Driver name to remove the filter from (since each driver only has
368  *	a single device)
369  * @filter_num: Filter number to remove (as returned by log_add_filter())
370  * @return 0 if the filter was removed, -ENOENT if either the driver or the
371  *	filter number was not found
372  */
373 int log_remove_filter(const char *drv_name, int filter_num);
374 
375 #if CONFIG_IS_ENABLED(LOG)
376 /**
377  * log_init() - Set up the log system ready for use
378  *
379  * @return 0 if OK, -ENOMEM if out of memory
380  */
381 int log_init(void);
382 #else
383 static inline int log_init(void)
384 {
385 	return 0;
386 }
387 #endif
388 
389 #endif
390