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 __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
log_init(void)405 static inline int log_init(void)
406 {
407 return 0;
408 }
409 #endif
410
411 #endif
412