1 /*
2 * Logging support
3 *
4 * Copyright (c) 2017 Google, Inc
5 * Written by Simon Glass <sjg@chromium.org>
6 *
7 * SPDX-License-Identifier: GPL-2.0+
8 */
9
10 #ifndef __LOG_H
11 #define __LOG_H
12
13 #include <dm/uclass-id.h>
14 #include <linux/list.h>
15
16 /** Log levels supported, ranging from most to least important */
17 enum log_level_t {
18 LOGL_EMERG = 0, /*U-Boot is unstable */
19 LOGL_ALERT, /* Action must be taken immediately */
20 LOGL_CRIT, /* Critical conditions */
21 LOGL_ERR, /* Error that prevents something from working */
22 LOGL_WARNING, /* Warning may prevent optimial operation */
23 LOGL_NOTICE, /* Normal but significant condition, printf() */
24 LOGL_INFO, /* General information message */
25 LOGL_DEBUG, /* Basic debug-level message */
26 LOGL_DEBUG_CONTENT, /* Debug message showing full message content */
27 LOGL_DEBUG_IO, /* Debug message showing hardware I/O access */
28
29 LOGL_COUNT,
30 LOGL_FIRST = LOGL_EMERG,
31 LOGL_MAX = LOGL_DEBUG,
32 };
33
34 /**
35 * Log categories supported. Most of these correspond to uclasses (i.e.
36 * enum uclass_id) but there are also some more generic categories
37 */
38 enum log_category_t {
39 LOGC_FIRST = 0, /* First part mirrors UCLASS_... */
40
41 LOGC_NONE = UCLASS_COUNT,
42 LOGC_ARCH,
43 LOGC_BOARD,
44 LOGC_CORE,
45 LOGC_DM, /* Core driver-model */
46 LOGC_DT, /* Device-tree */
47 LOGC_EFI, /* EFI implementation */
48 LOGC_ALLOC, /* Memory allocation */
49
50 LOGC_COUNT,
51 LOGC_END,
52 };
53
54 /* Helper to cast a uclass ID to a log category */
log_uc_cat(enum uclass_id id)55 static inline int log_uc_cat(enum uclass_id id)
56 {
57 return (enum log_category_t)id;
58 }
59
60 /**
61 * _log() - Internal function to emit a new log record
62 *
63 * @cat: Category of log record (indicating which subsystem generated it)
64 * @level: Level of log record (indicating its severity)
65 * @file: File name of file where log record was generated
66 * @line: Line number in file where log record was generated
67 * @func: Function where log record was generated
68 * @fmt: printf() format string for log record
69 * @...: Optional parameters, according to the format string @fmt
70 * @return 0 if log record was emitted, -ve on error
71 */
72 int _log(enum log_category_t cat, enum log_level_t level, const char *file,
73 int line, const char *func, const char *fmt, ...);
74
75 /* Define this at the top of a file to add a prefix to debug messages */
76 #ifndef pr_fmt
77 #define pr_fmt(fmt) fmt
78 #endif
79
80 /* Use a default category if this file does not supply one */
81 #ifndef LOG_CATEGORY
82 #define LOG_CATEGORY LOGC_NONE
83 #endif
84
85 /*
86 * This header may be including when CONFIG_LOG is disabled, in which case
87 * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
88 */
89 #if CONFIG_IS_ENABLED(LOG)
90 #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
91 #else
92 #define _LOG_MAX_LEVEL LOGL_INFO
93 #endif
94
95 /* Emit a log record if the level is less that the maximum */
96 #define log(_cat, _level, _fmt, _args...) ({ \
97 int _l = _level; \
98 if (_l <= _LOG_MAX_LEVEL) \
99 _log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
100 __func__, \
101 pr_fmt(_fmt), ##_args); \
102 })
103
104 #ifdef DEBUG
105 #define _DEBUG 1
106 #else
107 #define _DEBUG 0
108 #endif
109
110 #ifdef CONFIG_SPL_BUILD
111 #define _SPL_BUILD 1
112 #else
113 #define _SPL_BUILD 0
114 #endif
115
116 #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
117
118 #define debug_cond(cond, fmt, args...) \
119 do { \
120 if (1) \
121 log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
122 } while (0)
123
124 #else /* _DEBUG */
125
126 /*
127 * Output a debug text when condition "cond" is met. The "cond" should be
128 * computed by a preprocessor in the best case, allowing for the best
129 * optimization.
130 */
131 #define debug_cond(cond, fmt, args...) \
132 do { \
133 if (cond) \
134 printf(pr_fmt(fmt), ##args); \
135 } while (0)
136
137 #endif /* _DEBUG */
138
139 /* Show a message if DEBUG is defined in a file */
140 #define debug(fmt, args...) \
141 debug_cond(_DEBUG, fmt, ##args)
142
143 /* Show a message if not in SPL */
144 #define warn_non_spl(fmt, args...) \
145 debug_cond(!_SPL_BUILD, fmt, ##args)
146
147 /*
148 * An assertion is run-time check done in debug mode only. If DEBUG is not
149 * defined then it is skipped. If DEBUG is defined and the assertion fails,
150 * then it calls panic*( which may or may not reset/halt U-Boot (see
151 * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
152 * before release, and after release it is hoped that they don't matter. But
153 * in any case these failing assertions cannot be fixed with a reset (which
154 * may just do the same assertion again).
155 */
156 void __assert_fail(const char *assertion, const char *file, unsigned int line,
157 const char *function);
158 #define assert(x) \
159 ({ if (!(x) && _DEBUG) \
160 __assert_fail(#x, __FILE__, __LINE__, __func__); })
161
162 #ifdef CONFIG_LOG_ERROR_RETURN
163 #define log_ret(_ret) ({ \
164 int __ret = (_ret); \
165 if (__ret < 0) \
166 log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
167 __ret; \
168 })
169 #define log_msg_ret(_msg, _ret) ({ \
170 int __ret = (_ret); \
171 if (__ret < 0) \
172 log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
173 __ret); \
174 __ret; \
175 })
176 #else
177 #define log_ret(_ret) (_ret)
178 #define log_msg_ret(_msg, _ret) (_ret)
179 #endif
180
181 /**
182 * struct log_rec - a single log record
183 *
184 * Holds information about a single record in the log
185 *
186 * Members marked as 'not allocated' are stored as pointers and the caller is
187 * responsible for making sure that the data pointed to is not overwritten.
188 * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
189 * system.
190 *
191 * @cat: Category, representing a uclass or part of U-Boot
192 * @level: Severity level, less severe is higher
193 * @file: Name of file where the log record was generated (not allocated)
194 * @line: Line number where the log record was generated
195 * @func: Function where the log record was generated (not allocated)
196 * @msg: Log message (allocated)
197 */
198 struct log_rec {
199 enum log_category_t cat;
200 enum log_level_t level;
201 const char *file;
202 int line;
203 const char *func;
204 const char *msg;
205 };
206
207 struct log_device;
208
209 /**
210 * struct log_driver - a driver which accepts and processes log records
211 *
212 * @name: Name of driver
213 */
214 struct log_driver {
215 const char *name;
216 /**
217 * emit() - emit a log record
218 *
219 * Called by the log system to pass a log record to a particular driver
220 * for processing. The filter is checked before calling this function.
221 */
222 int (*emit)(struct log_device *ldev, struct log_rec *rec);
223 };
224
225 /**
226 * struct log_device - an instance of a log driver
227 *
228 * Since drivers are set up at build-time we need to have a separate device for
229 * the run-time aspects of drivers (currently just a list of filters to apply
230 * to records send to this device).
231 *
232 * @next_filter_num: Seqence number of next filter filter added (0=no filters
233 * yet). This increments with each new filter on the device, but never
234 * decrements
235 * @drv: Pointer to driver for this device
236 * @filter_head: List of filters for this device
237 * @sibling_node: Next device in the list of all devices
238 */
239 struct log_device {
240 int next_filter_num;
241 struct log_driver *drv;
242 struct list_head filter_head;
243 struct list_head sibling_node;
244 };
245
246 enum {
247 LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */
248 };
249
250 enum log_filter_flags {
251 LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */
252 };
253
254 /**
255 * struct log_filter - criterial to filter out log messages
256 *
257 * @filter_num: Sequence number of this filter. This is returned when adding a
258 * new filter, and must be provided when removing a previously added
259 * filter.
260 * @flags: Flags for this filter (LOGFF_...)
261 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
262 * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
263 * can be provided
264 * @max_level: Maximum log level to allow
265 * @file_list: List of files to allow, separated by comma. If NULL then all
266 * files are permitted
267 * @sibling_node: Next filter in the list of filters for this log device
268 */
269 struct log_filter {
270 int filter_num;
271 int flags;
272 enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
273 enum log_level_t max_level;
274 const char *file_list;
275 struct list_head sibling_node;
276 };
277
278 #define LOG_DRIVER(_name) \
279 ll_entry_declare(struct log_driver, _name, log_driver)
280
281 /* Handle the 'log test' command */
282 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
283
284 /**
285 * log_add_filter() - Add a new filter to a log device
286 *
287 * @drv_name: Driver name to add the filter to (since each driver only has a
288 * single device)
289 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
290 * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
291 * can be provided
292 * @max_level: Maximum log level to allow
293 * @file_list: List of files to allow, separated by comma. If NULL then all
294 * files are permitted
295 * @return the sequence number of the new filter (>=0) if the filter was added,
296 * or a -ve value on error
297 */
298 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
299 enum log_level_t max_level, const char *file_list);
300
301 /**
302 * log_remove_filter() - Remove a filter from a log device
303 *
304 * @drv_name: Driver name to remove the filter from (since each driver only has
305 * a single device)
306 * @filter_num: Filter number to remove (as returned by log_add_filter())
307 * @return 0 if the filter was removed, -ENOENT if either the driver or the
308 * filter number was not found
309 */
310 int log_remove_filter(const char *drv_name, int filter_num);
311
312 #if CONFIG_IS_ENABLED(LOG)
313 /**
314 * log_init() - Set up the log system ready for use
315 *
316 * @return 0 if OK, -ENOMEM if out of memory
317 */
318 int log_init(void);
319 #else
log_init(void)320 static inline int log_init(void)
321 {
322 return 0;
323 }
324 #endif
325
326 #endif
327