log.h 10 KB

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  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. #ifndef __LOG_H
  9. #define __LOG_H
  10. #include <dm/uclass-id.h>
  11. #include <linux/list.h>
  12. /** Log levels supported, ranging from most to least important */
  13. enum log_level_t {
  14. LOGL_EMERG = 0, /*U-Boot is unstable */
  15. LOGL_ALERT, /* Action must be taken immediately */
  16. LOGL_CRIT, /* Critical conditions */
  17. LOGL_ERR, /* Error that prevents something from working */
  18. LOGL_WARNING, /* Warning may prevent optimial operation */
  19. LOGL_NOTICE, /* Normal but significant condition, printf() */
  20. LOGL_INFO, /* General information message */
  21. LOGL_DEBUG, /* Basic debug-level message */
  22. LOGL_DEBUG_CONTENT, /* Debug message showing full message content */
  23. LOGL_DEBUG_IO, /* Debug message showing hardware I/O access */
  24. LOGL_COUNT,
  25. LOGL_NONE,
  26. LOGL_FIRST = LOGL_EMERG,
  27. LOGL_MAX = LOGL_DEBUG_IO,
  28. };
  29. /**
  30. * Log categories supported. Most of these correspond to uclasses (i.e.
  31. * enum uclass_id) but there are also some more generic categories
  32. */
  33. enum log_category_t {
  34. LOGC_FIRST = 0, /* First part mirrors UCLASS_... */
  35. LOGC_NONE = UCLASS_COUNT,
  36. LOGC_ARCH,
  37. LOGC_BOARD,
  38. LOGC_CORE,
  39. LOGC_DM, /* Core driver-model */
  40. LOGC_DT, /* Device-tree */
  41. LOGC_EFI, /* EFI implementation */
  42. LOGC_COUNT,
  43. LOGC_END,
  44. };
  45. /* Helper to cast a uclass ID to a log category */
  46. static inline int log_uc_cat(enum uclass_id id)
  47. {
  48. return (enum log_category_t)id;
  49. }
  50. /**
  51. * _log() - Internal function to emit a new log record
  52. *
  53. * @cat: Category of log record (indicating which subsystem generated it)
  54. * @level: Level of log record (indicating its severity)
  55. * @file: File name of file where log record was generated
  56. * @line: Line number in file where log record was generated
  57. * @func: Function where log record was generated
  58. * @fmt: printf() format string for log record
  59. * @...: Optional parameters, according to the format string @fmt
  60. * @return 0 if log record was emitted, -ve on error
  61. */
  62. int _log(enum log_category_t cat, enum log_level_t level, const char *file,
  63. int line, const char *func, const char *fmt, ...);
  64. /* Define this at the top of a file to add a prefix to debug messages */
  65. #ifndef pr_fmt
  66. #define pr_fmt(fmt) fmt
  67. #endif
  68. /* Use a default category if this file does not supply one */
  69. #ifndef LOG_CATEGORY
  70. #define LOG_CATEGORY LOGC_NONE
  71. #endif
  72. /*
  73. * This header may be including when CONFIG_LOG is disabled, in which case
  74. * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
  75. */
  76. #if CONFIG_IS_ENABLED(LOG)
  77. #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
  78. #else
  79. #define _LOG_MAX_LEVEL LOGL_INFO
  80. #endif
  81. /* Emit a log record if the level is less that the maximum */
  82. #define log(_cat, _level, _fmt, _args...) ({ \
  83. int _l = _level; \
  84. if (_l <= _LOG_MAX_LEVEL) \
  85. _log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
  86. __func__, \
  87. pr_fmt(_fmt), ##_args); \
  88. })
  89. #ifdef DEBUG
  90. #define _DEBUG 1
  91. #else
  92. #define _DEBUG 0
  93. #endif
  94. #ifdef CONFIG_SPL_BUILD
  95. #define _SPL_BUILD 1
  96. #else
  97. #define _SPL_BUILD 0
  98. #endif
  99. #if !_DEBUG && CONFIG_IS_ENABLED(LOG)
  100. #define debug_cond(cond, fmt, args...) \
  101. do { \
  102. if (1) \
  103. log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
  104. } while (0)
  105. #else /* _DEBUG */
  106. /*
  107. * Output a debug text when condition "cond" is met. The "cond" should be
  108. * computed by a preprocessor in the best case, allowing for the best
  109. * optimization.
  110. */
  111. #define debug_cond(cond, fmt, args...) \
  112. do { \
  113. if (cond) \
  114. printf(pr_fmt(fmt), ##args); \
  115. } while (0)
  116. #endif /* _DEBUG */
  117. /* Show a message if DEBUG is defined in a file */
  118. #define debug(fmt, args...) \
  119. debug_cond(_DEBUG, fmt, ##args)
  120. /* Show a message if not in SPL */
  121. #define warn_non_spl(fmt, args...) \
  122. debug_cond(!_SPL_BUILD, fmt, ##args)
  123. /*
  124. * An assertion is run-time check done in debug mode only. If DEBUG is not
  125. * defined then it is skipped. If DEBUG is defined and the assertion fails,
  126. * then it calls panic*( which may or may not reset/halt U-Boot (see
  127. * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found
  128. * before release, and after release it is hoped that they don't matter. But
  129. * in any case these failing assertions cannot be fixed with a reset (which
  130. * may just do the same assertion again).
  131. */
  132. void __assert_fail(const char *assertion, const char *file, unsigned int line,
  133. const char *function);
  134. #define assert(x) \
  135. ({ if (!(x) && _DEBUG) \
  136. __assert_fail(#x, __FILE__, __LINE__, __func__); })
  137. #ifdef CONFIG_LOG_ERROR_RETURN
  138. #define log_ret(_ret) ({ \
  139. int __ret = (_ret); \
  140. if (__ret < 0) \
  141. log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
  142. __ret; \
  143. })
  144. #else
  145. #define log_ret(_ret) (_ret)
  146. #endif
  147. /**
  148. * struct log_rec - a single log record
  149. *
  150. * Holds information about a single record in the log
  151. *
  152. * Members marked as 'not allocated' are stored as pointers and the caller is
  153. * responsible for making sure that the data pointed to is not overwritten.
  154. * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
  155. * system.
  156. *
  157. * @cat: Category, representing a uclass or part of U-Boot
  158. * @level: Severity level, less severe is higher
  159. * @file: Name of file where the log record was generated (not allocated)
  160. * @line: Line number where the log record was generated
  161. * @func: Function where the log record was generated (not allocated)
  162. * @msg: Log message (allocated)
  163. */
  164. struct log_rec {
  165. enum log_category_t cat;
  166. enum log_level_t level;
  167. const char *file;
  168. int line;
  169. const char *func;
  170. const char *msg;
  171. };
  172. struct log_device;
  173. /**
  174. * struct log_driver - a driver which accepts and processes log records
  175. *
  176. * @name: Name of driver
  177. */
  178. struct log_driver {
  179. const char *name;
  180. /**
  181. * emit() - emit a log record
  182. *
  183. * Called by the log system to pass a log record to a particular driver
  184. * for processing. The filter is checked before calling this function.
  185. */
  186. int (*emit)(struct log_device *ldev, struct log_rec *rec);
  187. };
  188. /**
  189. * struct log_device - an instance of a log driver
  190. *
  191. * Since drivers are set up at build-time we need to have a separate device for
  192. * the run-time aspects of drivers (currently just a list of filters to apply
  193. * to records send to this device).
  194. *
  195. * @next_filter_num: Seqence number of next filter filter added (0=no filters
  196. * yet). This increments with each new filter on the device, but never
  197. * decrements
  198. * @drv: Pointer to driver for this device
  199. * @filter_head: List of filters for this device
  200. * @sibling_node: Next device in the list of all devices
  201. */
  202. struct log_device {
  203. int next_filter_num;
  204. struct log_driver *drv;
  205. struct list_head filter_head;
  206. struct list_head sibling_node;
  207. };
  208. enum {
  209. LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */
  210. };
  211. enum log_filter_flags {
  212. LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */
  213. };
  214. /**
  215. * struct log_filter - criterial to filter out log messages
  216. *
  217. * @filter_num: Sequence number of this filter. This is returned when adding a
  218. * new filter, and must be provided when removing a previously added
  219. * filter.
  220. * @flags: Flags for this filter (LOGFF_...)
  221. * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
  222. * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
  223. * can be provided
  224. * @max_level: Maximum log level to allow
  225. * @file_list: List of files to allow, separated by comma. If NULL then all
  226. * files are permitted
  227. * @sibling_node: Next filter in the list of filters for this log device
  228. */
  229. struct log_filter {
  230. int filter_num;
  231. int flags;
  232. enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
  233. enum log_level_t max_level;
  234. const char *file_list;
  235. struct list_head sibling_node;
  236. };
  237. #define LOG_DRIVER(_name) \
  238. ll_entry_declare(struct log_driver, _name, log_driver)
  239. /**
  240. * log_get_cat_name() - Get the name of a category
  241. *
  242. * @cat: Category to look up
  243. * @return category name (which may be a uclass driver name)
  244. */
  245. const char *log_get_cat_name(enum log_category_t cat);
  246. /**
  247. * log_get_cat_by_name() - Look up a category by name
  248. *
  249. * @name: Name to look up
  250. * @return category ID, or LOGC_NONE if not found
  251. */
  252. enum log_category_t log_get_cat_by_name(const char *name);
  253. /**
  254. * log_get_level_name() - Get the name of a log level
  255. *
  256. * @level: Log level to look up
  257. * @return log level name (in ALL CAPS)
  258. */
  259. const char *log_get_level_name(enum log_level_t level);
  260. /**
  261. * log_get_level_by_name() - Look up a log level by name
  262. *
  263. * @name: Name to look up
  264. * @return log level ID, or LOGL_NONE if not found
  265. */
  266. enum log_level_t log_get_level_by_name(const char *name);
  267. /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
  268. enum log_fmt {
  269. LOGF_CAT = 0,
  270. LOGF_LEVEL,
  271. LOGF_FILE,
  272. LOGF_LINE,
  273. LOGF_FUNC,
  274. LOGF_MSG,
  275. LOGF_COUNT,
  276. LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
  277. LOGF_ALL = 0x3f,
  278. };
  279. /* Handle the 'log test' command */
  280. int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
  281. /**
  282. * log_add_filter() - Add a new filter to a log device
  283. *
  284. * @drv_name: Driver name to add the filter to (since each driver only has a
  285. * single device)
  286. * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
  287. * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
  288. * can be provided
  289. * @max_level: Maximum log level to allow
  290. * @file_list: List of files to allow, separated by comma. If NULL then all
  291. * files are permitted
  292. * @return the sequence number of the new filter (>=0) if the filter was added,
  293. * or a -ve value on error
  294. */
  295. int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
  296. enum log_level_t max_level, const char *file_list);
  297. /**
  298. * log_remove_filter() - Remove a filter from a log device
  299. *
  300. * @drv_name: Driver name to remove the filter from (since each driver only has
  301. * a single device)
  302. * @filter_num: Filter number to remove (as returned by log_add_filter())
  303. * @return 0 if the filter was removed, -ENOENT if either the driver or the
  304. * filter number was not found
  305. */
  306. int log_remove_filter(const char *drv_name, int filter_num);
  307. #if CONFIG_IS_ENABLED(LOG)
  308. /**
  309. * log_init() - Set up the log system ready for use
  310. *
  311. * @return 0 if OK, -ENOMEM if out of memory
  312. */
  313. int log_init(void);
  314. #else
  315. static inline int log_init(void)
  316. {
  317. return 0;
  318. }
  319. #endif
  320. #endif