xref: /openbmc/u-boot/include/log.h (revision b9553986)
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 #ifdef LOG_DEBUG
115 #define _LOG_DEBUG	1
116 #else
117 #define _LOG_DEBUG	0
118 #endif
119 
120 /* Emit a log record if the level is less that the maximum */
121 #define log(_cat, _level, _fmt, _args...) ({ \
122 	int _l = _level; \
123 	if (CONFIG_IS_ENABLED(LOG) && (_l <= _LOG_MAX_LEVEL || _LOG_DEBUG)) \
124 		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
125 		      __func__, \
126 		      pr_fmt(_fmt), ##_args); \
127 	})
128 #else
129 #define log(_cat, _level, _fmt, _args...)
130 #endif
131 
132 #ifdef DEBUG
133 #define _DEBUG	1
134 #else
135 #define _DEBUG	0
136 #endif
137 
138 #ifdef CONFIG_SPL_BUILD
139 #define _SPL_BUILD	1
140 #else
141 #define _SPL_BUILD	0
142 #endif
143 
144 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
145 
146 #define debug_cond(cond, fmt, args...)			\
147 	do {						\
148 		if (1)					\
149 			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
150 	} while (0)
151 
152 #else /* _DEBUG */
153 
154 /*
155  * Output a debug text when condition "cond" is met. The "cond" should be
156  * computed by a preprocessor in the best case, allowing for the best
157  * optimization.
158  */
159 #define debug_cond(cond, fmt, args...)			\
160 	do {						\
161 		if (cond)				\
162 			printf(pr_fmt(fmt), ##args);	\
163 	} while (0)
164 
165 #endif /* _DEBUG */
166 
167 /* Show a message if DEBUG is defined in a file */
168 #define debug(fmt, args...)			\
169 	debug_cond(_DEBUG, fmt, ##args)
170 
171 /* Show a message if not in SPL */
172 #define warn_non_spl(fmt, args...)			\
173 	debug_cond(!_SPL_BUILD, fmt, ##args)
174 
175 /*
176  * An assertion is run-time check done in debug mode only. If DEBUG is not
177  * defined then it is skipped. If DEBUG is defined and the assertion fails,
178  * then it calls panic*( which may or may not reset/halt U-Boot (see
179  * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
180  * before release, and after release it is hoped that they don't matter. But
181  * in any case these failing assertions cannot be fixed with a reset (which
182  * may just do the same assertion again).
183  */
184 void __assert_fail(const char *assertion, const char *file, unsigned int line,
185 		   const char *function);
186 #define assert(x) \
187 	({ if (!(x) && _DEBUG) \
188 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
189 
190 #if CONFIG_IS_ENABLED(LOG) && defined(CONFIG_LOG_ERROR_RETURN)
191 /*
192  * Log an error return value, possibly with a message. Usage:
193  *
194  *	return log_ret(fred_call());
195  *
196  * or:
197  *
198  *	return log_msg_ret("fred failed", fred_call());
199  */
200 #define log_ret(_ret) ({ \
201 	int __ret = (_ret); \
202 	if (__ret < 0) \
203 		log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
204 	__ret; \
205 	})
206 #define log_msg_ret(_msg, _ret) ({ \
207 	int __ret = (_ret); \
208 	if (__ret < 0) \
209 		log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
210 		    __ret); \
211 	__ret; \
212 	})
213 #else
214 /* Non-logging versions of the above which just return the error code */
215 #define log_ret(_ret) (_ret)
216 #define log_msg_ret(_msg, _ret) ((void)(_msg), _ret)
217 #endif
218 
219 /**
220  * struct log_rec - a single log record
221  *
222  * Holds information about a single record in the log
223  *
224  * Members marked as 'not allocated' are stored as pointers and the caller is
225  * responsible for making sure that the data pointed to is not overwritten.
226  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
227  * system.
228  *
229  * @cat: Category, representing a uclass or part of U-Boot
230  * @level: Severity level, less severe is higher
231  * @file: Name of file where the log record was generated (not allocated)
232  * @line: Line number where the log record was generated
233  * @func: Function where the log record was generated (not allocated)
234  * @msg: Log message (allocated)
235  */
236 struct log_rec {
237 	enum log_category_t cat;
238 	enum log_level_t level;
239 	const char *file;
240 	int line;
241 	const char *func;
242 	const char *msg;
243 };
244 
245 struct log_device;
246 
247 /**
248  * struct log_driver - a driver which accepts and processes log records
249  *
250  * @name: Name of driver
251  */
252 struct log_driver {
253 	const char *name;
254 	/**
255 	 * emit() - emit a log record
256 	 *
257 	 * Called by the log system to pass a log record to a particular driver
258 	 * for processing. The filter is checked before calling this function.
259 	 */
260 	int (*emit)(struct log_device *ldev, struct log_rec *rec);
261 };
262 
263 /**
264  * struct log_device - an instance of a log driver
265  *
266  * Since drivers are set up at build-time we need to have a separate device for
267  * the run-time aspects of drivers (currently just a list of filters to apply
268  * to records send to this device).
269  *
270  * @next_filter_num: Seqence number of next filter filter added (0=no filters
271  *	yet). This increments with each new filter on the device, but never
272  *	decrements
273  * @drv: Pointer to driver for this device
274  * @filter_head: List of filters for this device
275  * @sibling_node: Next device in the list of all devices
276  */
277 struct log_device {
278 	int next_filter_num;
279 	struct log_driver *drv;
280 	struct list_head filter_head;
281 	struct list_head sibling_node;
282 };
283 
284 enum {
285 	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
286 };
287 
288 enum log_filter_flags {
289 	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
290 };
291 
292 /**
293  * struct log_filter - criterial to filter out log messages
294  *
295  * @filter_num: Sequence number of this filter.  This is returned when adding a
296  *	new filter, and must be provided when removing a previously added
297  *	filter.
298  * @flags: Flags for this filter (LOGFF_...)
299  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
300  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
301  *	can be provided
302  * @max_level: Maximum log level to allow
303  * @file_list: List of files to allow, separated by comma. If NULL then all
304  *	files are permitted
305  * @sibling_node: Next filter in the list of filters for this log device
306  */
307 struct log_filter {
308 	int filter_num;
309 	int flags;
310 	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
311 	enum log_level_t max_level;
312 	const char *file_list;
313 	struct list_head sibling_node;
314 };
315 
316 #define LOG_DRIVER(_name) \
317 	ll_entry_declare(struct log_driver, _name, log_driver)
318 
319 /**
320  * log_get_cat_name() - Get the name of a category
321  *
322  * @cat: Category to look up
323  * @return category name (which may be a uclass driver name) if found, or
324  *	 "<invalid>" if invalid, or "<missing>" if not found
325  */
326 const char *log_get_cat_name(enum log_category_t cat);
327 
328 /**
329  * log_get_cat_by_name() - Look up a category by name
330  *
331  * @name: Name to look up
332  * @return category ID, or LOGC_NONE if not found
333  */
334 enum log_category_t log_get_cat_by_name(const char *name);
335 
336 /**
337  * log_get_level_name() - Get the name of a log level
338  *
339  * @level: Log level to look up
340  * @return log level name (in ALL CAPS)
341  */
342 const char *log_get_level_name(enum log_level_t level);
343 
344 /**
345  * log_get_level_by_name() - Look up a log level by name
346  *
347  * @name: Name to look up
348  * @return log level ID, or LOGL_NONE if not found
349  */
350 enum log_level_t log_get_level_by_name(const char *name);
351 
352 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
353 enum log_fmt {
354 	LOGF_CAT	= 0,
355 	LOGF_LEVEL,
356 	LOGF_FILE,
357 	LOGF_LINE,
358 	LOGF_FUNC,
359 	LOGF_MSG,
360 
361 	LOGF_COUNT,
362 	LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
363 	LOGF_ALL = 0x3f,
364 };
365 
366 /* Handle the 'log test' command */
367 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
368 
369 /**
370  * log_add_filter() - Add a new filter to a log device
371  *
372  * @drv_name: Driver name to add the filter to (since each driver only has a
373  *	single device)
374  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
375  *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
376  *	can be provided
377  * @max_level: Maximum log level to allow
378  * @file_list: List of files to allow, separated by comma. If NULL then all
379  *	files are permitted
380  * @return the sequence number of the new filter (>=0) if the filter was added,
381  *	or a -ve value on error
382  */
383 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
384 		   enum log_level_t max_level, const char *file_list);
385 
386 /**
387  * log_remove_filter() - Remove a filter from a log device
388  *
389  * @drv_name: Driver name to remove the filter from (since each driver only has
390  *	a single device)
391  * @filter_num: Filter number to remove (as returned by log_add_filter())
392  * @return 0 if the filter was removed, -ENOENT if either the driver or the
393  *	filter number was not found
394  */
395 int log_remove_filter(const char *drv_name, int filter_num);
396 
397 #if CONFIG_IS_ENABLED(LOG)
398 /**
399  * log_init() - Set up the log system ready for use
400  *
401  * @return 0 if OK, -ENOMEM if out of memory
402  */
403 int log_init(void);
404 #else
405 static inline int log_init(void)
406 {
407 	return 0;
408 }
409 #endif
410 
411 #endif
412