xref: /openbmc/u-boot/include/log.h (revision 7b3af03f)
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 
78 /* Define this at the top of a file to add a prefix to debug messages */
79 #ifndef pr_fmt
80 #define pr_fmt(fmt) fmt
81 #endif
82 
83 /* Use a default category if this file does not supply one */
84 #ifndef LOG_CATEGORY
85 #define LOG_CATEGORY LOGC_NONE
86 #endif
87 
88 /*
89  * This header may be including when CONFIG_LOG is disabled, in which case
90  * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
91  */
92 #if CONFIG_IS_ENABLED(LOG)
93 #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
94 #define log_err(_fmt...)	log(LOG_CATEGORY, LOGL_ERR, ##_fmt)
95 #define log_warning(_fmt...)	log(LOG_CATEGORY, LOGL_WARNING, ##_fmt)
96 #define log_notice(_fmt...)	log(LOG_CATEGORY, LOGL_NOTICE, ##_fmt)
97 #define log_info(_fmt...)	log(LOG_CATEGORY, LOGL_INFO, ##_fmt)
98 #define log_debug(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG, ##_fmt)
99 #define log_content(_fmt...)	log(LOG_CATEGORY, LOGL_DEBUG_CONTENT, ##_fmt)
100 #define log_io(_fmt...)		log(LOG_CATEGORY, LOGL_DEBUG_IO, ##_fmt)
101 #else
102 #define _LOG_MAX_LEVEL LOGL_INFO
103 #define log_err(_fmt...)
104 #define log_warning(_fmt...)
105 #define log_notice(_fmt...)
106 #define log_info(_fmt...)
107 #define log_debug(_fmt...)
108 #define log_content(_fmt...)
109 #define log_io(_fmt...)
110 #endif
111 
112 #if CONFIG_IS_ENABLED(LOG)
113 
114 /* Emit a log record if the level is less that the maximum */
115 #define log(_cat, _level, _fmt, _args...) ({ \
116 	int _l = _level; \
117 	if (_l <= _LOG_MAX_LEVEL) \
118 		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
119 		      __func__, \
120 		      pr_fmt(_fmt), ##_args); \
121 	})
122 #else
123 #define log(_cat, _level, _fmt, _args...)
124 #endif
125 
126 #ifdef DEBUG
127 #define _DEBUG	1
128 #else
129 #define _DEBUG	0
130 #endif
131 
132 #ifdef CONFIG_SPL_BUILD
133 #define _SPL_BUILD	1
134 #else
135 #define _SPL_BUILD	0
136 #endif
137 
138 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
139 
140 #define debug_cond(cond, fmt, args...)			\
141 	do {						\
142 		if (1)					\
143 			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
144 	} while (0)
145 
146 #else /* _DEBUG */
147 
148 /*
149  * Output a debug text when condition "cond" is met. The "cond" should be
150  * computed by a preprocessor in the best case, allowing for the best
151  * optimization.
152  */
153 #define debug_cond(cond, fmt, args...)			\
154 	do {						\
155 		if (cond)				\
156 			printf(pr_fmt(fmt), ##args);	\
157 	} while (0)
158 
159 #endif /* _DEBUG */
160 
161 /* Show a message if DEBUG is defined in a file */
162 #define debug(fmt, args...)			\
163 	debug_cond(_DEBUG, fmt, ##args)
164 
165 /* Show a message if not in SPL */
166 #define warn_non_spl(fmt, args...)			\
167 	debug_cond(!_SPL_BUILD, fmt, ##args)
168 
169 /*
170  * An assertion is run-time check done in debug mode only. If DEBUG is not
171  * defined then it is skipped. If DEBUG is defined and the assertion fails,
172  * then it calls panic*( which may or may not reset/halt U-Boot (see
173  * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
174  * before release, and after release it is hoped that they don't matter. But
175  * in any case these failing assertions cannot be fixed with a reset (which
176  * may just do the same assertion again).
177  */
178 void __assert_fail(const char *assertion, const char *file, unsigned int line,
179 		   const char *function);
180 #define assert(x) \
181 	({ if (!(x) && _DEBUG) \
182 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
183 
184 #if CONFIG_IS_ENABLED(LOG) && defined(CONFIG_LOG_ERROR_RETURN)
185 /*
186  * Log an error return value, possibly with a message. Usage:
187  *
188  *	return log_ret(fred_call());
189  *
190  * or:
191  *
192  *	return log_msg_ret("fred failed", fred_call());
193  */
194 #define log_ret(_ret) ({ \
195 	int __ret = (_ret); \
196 	if (__ret < 0) \
197 		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
198 	__ret; \
199 	})
200 #define log_msg_ret(_msg, _ret) ({ \
201 	int __ret = (_ret); \
202 	if (__ret < 0) \
203 		log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
204 		    __ret); \
205 	__ret; \
206 	})
207 #else
208 /* Non-logging versions of the above which just return the error code */
209 #define log_ret(_ret) (_ret)
210 #define log_msg_ret(_msg, _ret) ((void)(_msg), _ret)
211 #endif
212 
213 /**
214  * struct log_rec - a single log record
215  *
216  * Holds information about a single record in the log
217  *
218  * Members marked as 'not allocated' are stored as pointers and the caller is
219  * responsible for making sure that the data pointed to is not overwritten.
220  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
221  * system.
222  *
223  * @cat: Category, representing a uclass or part of U-Boot
224  * @level: Severity level, less severe is higher
225  * @file: Name of file where the log record was generated (not allocated)
226  * @line: Line number where the log record was generated
227  * @func: Function where the log record was generated (not allocated)
228  * @msg: Log message (allocated)
229  */
230 struct log_rec {
231 	enum log_category_t cat;
232 	enum log_level_t level;
233 	const char *file;
234 	int line;
235 	const char *func;
236 	const char *msg;
237 };
238 
239 struct log_device;
240 
241 /**
242  * struct log_driver - a driver which accepts and processes log records
243  *
244  * @name: Name of driver
245  */
246 struct log_driver {
247 	const char *name;
248 	/**
249 	 * emit() - emit a log record
250 	 *
251 	 * Called by the log system to pass a log record to a particular driver
252 	 * for processing. The filter is checked before calling this function.
253 	 */
254 	int (*emit)(struct log_device *ldev, struct log_rec *rec);
255 };
256 
257 /**
258  * struct log_device - an instance of a log driver
259  *
260  * Since drivers are set up at build-time we need to have a separate device for
261  * the run-time aspects of drivers (currently just a list of filters to apply
262  * to records send to this device).
263  *
264  * @next_filter_num: Seqence number of next filter filter added (0=no filters
265  *	yet). This increments with each new filter on the device, but never
266  *	decrements
267  * @drv: Pointer to driver for this device
268  * @filter_head: List of filters for this device
269  * @sibling_node: Next device in the list of all devices
270  */
271 struct log_device {
272 	int next_filter_num;
273 	struct log_driver *drv;
274 	struct list_head filter_head;
275 	struct list_head sibling_node;
276 };
277 
278 enum {
279 	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
280 };
281 
282 enum log_filter_flags {
283 	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
284 };
285 
286 /**
287  * struct log_filter - criterial to filter out log messages
288  *
289  * @filter_num: Sequence number of this filter.  This is returned when adding a
290  *	new filter, and must be provided when removing a previously added
291  *	filter.
292  * @flags: Flags for this filter (LOGFF_...)
293  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
294  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
295  *	can be provided
296  * @max_level: Maximum log level to allow
297  * @file_list: List of files to allow, separated by comma. If NULL then all
298  *	files are permitted
299  * @sibling_node: Next filter in the list of filters for this log device
300  */
301 struct log_filter {
302 	int filter_num;
303 	int flags;
304 	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
305 	enum log_level_t max_level;
306 	const char *file_list;
307 	struct list_head sibling_node;
308 };
309 
310 #define LOG_DRIVER(_name) \
311 	ll_entry_declare(struct log_driver, _name, log_driver)
312 
313 /**
314  * log_get_cat_name() - Get the name of a category
315  *
316  * @cat: Category to look up
317  * @return category name (which may be a uclass driver name) if found, or
318  *	 "<invalid>" if invalid, or "<missing>" if not found
319  */
320 const char *log_get_cat_name(enum log_category_t cat);
321 
322 /**
323  * log_get_cat_by_name() - Look up a category by name
324  *
325  * @name: Name to look up
326  * @return category ID, or LOGC_NONE if not found
327  */
328 enum log_category_t log_get_cat_by_name(const char *name);
329 
330 /**
331  * log_get_level_name() - Get the name of a log level
332  *
333  * @level: Log level to look up
334  * @return log level name (in ALL CAPS)
335  */
336 const char *log_get_level_name(enum log_level_t level);
337 
338 /**
339  * log_get_level_by_name() - Look up a log level by name
340  *
341  * @name: Name to look up
342  * @return log level ID, or LOGL_NONE if not found
343  */
344 enum log_level_t log_get_level_by_name(const char *name);
345 
346 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
347 enum log_fmt {
348 	LOGF_CAT	= 0,
349 	LOGF_LEVEL,
350 	LOGF_FILE,
351 	LOGF_LINE,
352 	LOGF_FUNC,
353 	LOGF_MSG,
354 
355 	LOGF_COUNT,
356 	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
357 	LOGF_ALL = 0x3f,
358 };
359 
360 /* Handle the 'log test' command */
361 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
362 
363 /**
364  * log_add_filter() - Add a new filter to a log device
365  *
366  * @drv_name: Driver name to add the filter to (since each driver only has a
367  *	single device)
368  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
369  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
370  *	can be provided
371  * @max_level: Maximum log level to allow
372  * @file_list: List of files to allow, separated by comma. If NULL then all
373  *	files are permitted
374  * @return the sequence number of the new filter (>=0) if the filter was added,
375  *	or a -ve value on error
376  */
377 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
378 		   enum log_level_t max_level, const char *file_list);
379 
380 /**
381  * log_remove_filter() - Remove a filter from a log device
382  *
383  * @drv_name: Driver name to remove the filter from (since each driver only has
384  *	a single device)
385  * @filter_num: Filter number to remove (as returned by log_add_filter())
386  * @return 0 if the filter was removed, -ENOENT if either the driver or the
387  *	filter number was not found
388  */
389 int log_remove_filter(const char *drv_name, int filter_num);
390 
391 #if CONFIG_IS_ENABLED(LOG)
392 /**
393  * log_init() - Set up the log system ready for use
394  *
395  * @return 0 if OK, -ENOMEM if out of memory
396  */
397 int log_init(void);
398 #else
399 static inline int log_init(void)
400 {
401 	return 0;
402 }
403 #endif
404 
405 #endif
406