xref: /openbmc/u-boot/include/log.h (revision 0e620729)
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 	LOGC_BLOBLIST,	/* Bloblist */
52 
53 	LOGC_COUNT,	/* Number of log categories */
54 	LOGC_END,	/* Sentinel value for a list of log categories */
55 };
56 
57 /* Helper to cast a uclass ID to a log category */
58 static inline int log_uc_cat(enum uclass_id id)
59 {
60 	return (enum log_category_t)id;
61 }
62 
63 /**
64  * _log() - Internal function to emit a new log record
65  *
66  * @cat: Category of log record (indicating which subsystem generated it)
67  * @level: Level of log record (indicating its severity)
68  * @file: File name of file where log record was generated
69  * @line: Line number in file where log record was generated
70  * @func: Function where log record was generated
71  * @fmt: printf() format string for log record
72  * @...: Optional parameters, according to the format string @fmt
73  * @return 0 if log record was emitted, -ve on error
74  */
75 int _log(enum log_category_t cat, enum log_level_t level, const char *file,
76 	 int line, const char *func, const char *fmt, ...)
77 		__attribute__ ((format (__printf__, 6, 7)));
78 
79 /* Define this at the top of a file to add a prefix to debug messages */
80 #ifndef pr_fmt
81 #define pr_fmt(fmt) fmt
82 #endif
83 
84 /* Use a default category if this file does not supply one */
85 #ifndef LOG_CATEGORY
86 #define LOG_CATEGORY LOGC_NONE
87 #endif
88 
89 /*
90  * This header may be including when CONFIG_LOG is disabled, in which case
91  * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
92  */
93 #if CONFIG_IS_ENABLED(LOG)
94 #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
95 #define log_err(_fmt...)	log(LOG_CATEGORY, LOGL_ERR, ##_fmt)
96 #define log_warning(_fmt...)	log(LOG_CATEGORY, LOGL_WARNING, ##_fmt)
97 #define log_notice(_fmt...)	log(LOG_CATEGORY, LOGL_NOTICE, ##_fmt)
98 #define log_info(_fmt...)	log(LOG_CATEGORY, LOGL_INFO, ##_fmt)
99 #define log_debug(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG, ##_fmt)
100 #define log_content(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG_CONTENT, ##_fmt)
101 #define log_io(_fmt...)		log(LOG_CATEGORY, LOGL_DEBUG_IO, ##_fmt)
102 #else
103 #define _LOG_MAX_LEVEL LOGL_INFO
104 #define log_err(_fmt...)
105 #define log_warning(_fmt...)
106 #define log_notice(_fmt...)
107 #define log_info(_fmt...)
108 #define log_debug(_fmt...)
109 #define log_content(_fmt...)
110 #define log_io(_fmt...)
111 #endif
112 
113 #if CONFIG_IS_ENABLED(LOG)
114 
115 /* Emit a log record if the level is less that the maximum */
116 #define log(_cat, _level, _fmt, _args...) ({ \
117 	int _l = _level; \
118 	if (CONFIG_IS_ENABLED(LOG) && _l <= _LOG_MAX_LEVEL) \
119 		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
120 		      __func__, \
121 		      pr_fmt(_fmt), ##_args); \
122 	})
123 #else
124 #define log(_cat, _level, _fmt, _args...)
125 #endif
126 
127 #ifdef DEBUG
128 #define _DEBUG	1
129 #else
130 #define _DEBUG	0
131 #endif
132 
133 #ifdef CONFIG_SPL_BUILD
134 #define _SPL_BUILD	1
135 #else
136 #define _SPL_BUILD	0
137 #endif
138 
139 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
140 
141 #define debug_cond(cond, fmt, args...)			\
142 	do {						\
143 		if (1)					\
144 			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
145 	} while (0)
146 
147 #else /* _DEBUG */
148 
149 /*
150  * Output a debug text when condition "cond" is met. The "cond" should be
151  * computed by a preprocessor in the best case, allowing for the best
152  * optimization.
153  */
154 #define debug_cond(cond, fmt, args...)			\
155 	do {						\
156 		if (cond)				\
157 			printf(pr_fmt(fmt), ##args);	\
158 	} while (0)
159 
160 #endif /* _DEBUG */
161 
162 /* Show a message if DEBUG is defined in a file */
163 #define debug(fmt, args...)			\
164 	debug_cond(_DEBUG, fmt, ##args)
165 
166 /* Show a message if not in SPL */
167 #define warn_non_spl(fmt, args...)			\
168 	debug_cond(!_SPL_BUILD, fmt, ##args)
169 
170 /*
171  * An assertion is run-time check done in debug mode only. If DEBUG is not
172  * defined then it is skipped. If DEBUG is defined and the assertion fails,
173  * then it calls panic*( which may or may not reset/halt U-Boot (see
174  * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
175  * before release, and after release it is hoped that they don't matter. But
176  * in any case these failing assertions cannot be fixed with a reset (which
177  * may just do the same assertion again).
178  */
179 void __assert_fail(const char *assertion, const char *file, unsigned int line,
180 		   const char *function);
181 #define assert(x) \
182 	({ if (!(x) && _DEBUG) \
183 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
184 
185 #if CONFIG_IS_ENABLED(LOG) && defined(CONFIG_LOG_ERROR_RETURN)
186 /*
187  * Log an error return value, possibly with a message. Usage:
188  *
189  *	return log_ret(fred_call());
190  *
191  * or:
192  *
193  *	return log_msg_ret("fred failed", fred_call());
194  */
195 #define log_ret(_ret) ({ \
196 	int __ret = (_ret); \
197 	if (__ret < 0) \
198 		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
199 	__ret; \
200 	})
201 #define log_msg_ret(_msg, _ret) ({ \
202 	int __ret = (_ret); \
203 	if (__ret < 0) \
204 		log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
205 		    __ret); \
206 	__ret; \
207 	})
208 #else
209 /* Non-logging versions of the above which just return the error code */
210 #define log_ret(_ret) (_ret)
211 #define log_msg_ret(_msg, _ret) ((void)(_msg), _ret)
212 #endif
213 
214 /**
215  * struct log_rec - a single log record
216  *
217  * Holds information about a single record in the log
218  *
219  * Members marked as 'not allocated' are stored as pointers and the caller is
220  * responsible for making sure that the data pointed to is not overwritten.
221  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
222  * system.
223  *
224  * @cat: Category, representing a uclass or part of U-Boot
225  * @level: Severity level, less severe is higher
226  * @file: Name of file where the log record was generated (not allocated)
227  * @line: Line number where the log record was generated
228  * @func: Function where the log record was generated (not allocated)
229  * @msg: Log message (allocated)
230  */
231 struct log_rec {
232 	enum log_category_t cat;
233 	enum log_level_t level;
234 	const char *file;
235 	int line;
236 	const char *func;
237 	const char *msg;
238 };
239 
240 struct log_device;
241 
242 /**
243  * struct log_driver - a driver which accepts and processes log records
244  *
245  * @name: Name of driver
246  */
247 struct log_driver {
248 	const char *name;
249 	/**
250 	 * emit() - emit a log record
251 	 *
252 	 * Called by the log system to pass a log record to a particular driver
253 	 * for processing. The filter is checked before calling this function.
254 	 */
255 	int (*emit)(struct log_device *ldev, struct log_rec *rec);
256 };
257 
258 /**
259  * struct log_device - an instance of a log driver
260  *
261  * Since drivers are set up at build-time we need to have a separate device for
262  * the run-time aspects of drivers (currently just a list of filters to apply
263  * to records send to this device).
264  *
265  * @next_filter_num: Seqence number of next filter filter added (0=no filters
266  *	yet). This increments with each new filter on the device, but never
267  *	decrements
268  * @drv: Pointer to driver for this device
269  * @filter_head: List of filters for this device
270  * @sibling_node: Next device in the list of all devices
271  */
272 struct log_device {
273 	int next_filter_num;
274 	struct log_driver *drv;
275 	struct list_head filter_head;
276 	struct list_head sibling_node;
277 };
278 
279 enum {
280 	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
281 };
282 
283 enum log_filter_flags {
284 	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
285 };
286 
287 /**
288  * struct log_filter - criterial to filter out log messages
289  *
290  * @filter_num: Sequence number of this filter.  This is returned when adding a
291  *	new filter, and must be provided when removing a previously added
292  *	filter.
293  * @flags: Flags for this filter (LOGFF_...)
294  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
295  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
296  *	can be provided
297  * @max_level: Maximum log level to allow
298  * @file_list: List of files to allow, separated by comma. If NULL then all
299  *	files are permitted
300  * @sibling_node: Next filter in the list of filters for this log device
301  */
302 struct log_filter {
303 	int filter_num;
304 	int flags;
305 	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
306 	enum log_level_t max_level;
307 	const char *file_list;
308 	struct list_head sibling_node;
309 };
310 
311 #define LOG_DRIVER(_name) \
312 	ll_entry_declare(struct log_driver, _name, log_driver)
313 
314 /**
315  * log_get_cat_name() - Get the name of a category
316  *
317  * @cat: Category to look up
318  * @return category name (which may be a uclass driver name) if found, or
319  *	 "<invalid>" if invalid, or "<missing>" if not found
320  */
321 const char *log_get_cat_name(enum log_category_t cat);
322 
323 /**
324  * log_get_cat_by_name() - Look up a category by name
325  *
326  * @name: Name to look up
327  * @return category ID, or LOGC_NONE if not found
328  */
329 enum log_category_t log_get_cat_by_name(const char *name);
330 
331 /**
332  * log_get_level_name() - Get the name of a log level
333  *
334  * @level: Log level to look up
335  * @return log level name (in ALL CAPS)
336  */
337 const char *log_get_level_name(enum log_level_t level);
338 
339 /**
340  * log_get_level_by_name() - Look up a log level by name
341  *
342  * @name: Name to look up
343  * @return log level ID, or LOGL_NONE if not found
344  */
345 enum log_level_t log_get_level_by_name(const char *name);
346 
347 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
348 enum log_fmt {
349 	LOGF_CAT	= 0,
350 	LOGF_LEVEL,
351 	LOGF_FILE,
352 	LOGF_LINE,
353 	LOGF_FUNC,
354 	LOGF_MSG,
355 
356 	LOGF_COUNT,
357 	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
358 	LOGF_ALL = 0x3f,
359 };
360 
361 /* Handle the 'log test' command */
362 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
363 
364 /**
365  * log_add_filter() - Add a new filter to a log device
366  *
367  * @drv_name: Driver name to add the filter to (since each driver only has a
368  *	single device)
369  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
370  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
371  *	can be provided
372  * @max_level: Maximum log level to allow
373  * @file_list: List of files to allow, separated by comma. If NULL then all
374  *	files are permitted
375  * @return the sequence number of the new filter (>=0) if the filter was added,
376  *	or a -ve value on error
377  */
378 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
379 		   enum log_level_t max_level, const char *file_list);
380 
381 /**
382  * log_remove_filter() - Remove a filter from a log device
383  *
384  * @drv_name: Driver name to remove the filter from (since each driver only has
385  *	a single device)
386  * @filter_num: Filter number to remove (as returned by log_add_filter())
387  * @return 0 if the filter was removed, -ENOENT if either the driver or the
388  *	filter number was not found
389  */
390 int log_remove_filter(const char *drv_name, int filter_num);
391 
392 #if CONFIG_IS_ENABLED(LOG)
393 /**
394  * log_init() - Set up the log system ready for use
395  *
396  * @return 0 if OK, -ENOMEM if out of memory
397  */
398 int log_init(void);
399 #else
400 static inline int log_init(void)
401 {
402 	return 0;
403 }
404 #endif
405 
406 #endif
407