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 */
log_uc_cat(enum uclass_id id)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 (CONFIG_IS_ENABLED(LOG) && _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
log_init(void)399 static inline int log_init(void)
400 {
401 return 0;
402 }
403 #endif
404
405 #endif
406