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_DT, 46 47 LOGC_COUNT, 48 LOGC_END, 49 }; 50 51 /* Helper to cast a uclass ID to a log category */ 52 static inline int log_uc_cat(enum uclass_id id) 53 { 54 return (enum log_category_t)id; 55 } 56 57 /** 58 * _log() - Internal function to emit a new log record 59 * 60 * @cat: Category of log record (indicating which subsystem generated it) 61 * @level: Level of log record (indicating its severity) 62 * @file: File name of file where log record was generated 63 * @line: Line number in file where log record was generated 64 * @func: Function where log record was generated 65 * @fmt: printf() format string for log record 66 * @...: Optional parameters, according to the format string @fmt 67 * @return 0 if log record was emitted, -ve on error 68 */ 69 int _log(enum log_category_t cat, enum log_level_t level, const char *file, 70 int line, const char *func, const char *fmt, ...); 71 72 /* Define this at the top of a file to add a prefix to debug messages */ 73 #ifndef pr_fmt 74 #define pr_fmt(fmt) fmt 75 #endif 76 77 /* Use a default category if this file does not supply one */ 78 #ifndef LOG_CATEGORY 79 #define LOG_CATEGORY LOGC_NONE 80 #endif 81 82 /* 83 * This header may be including when CONFIG_LOG is disabled, in which case 84 * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this. 85 */ 86 #if CONFIG_IS_ENABLED(LOG) 87 #define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL) 88 #else 89 #define _LOG_MAX_LEVEL LOGL_INFO 90 #endif 91 92 /* Emit a log record if the level is less that the maximum */ 93 #define log(_cat, _level, _fmt, _args...) ({ \ 94 int _l = _level; \ 95 if (_l <= _LOG_MAX_LEVEL) \ 96 _log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \ 97 __func__, \ 98 pr_fmt(_fmt), ##_args); \ 99 }) 100 101 #ifdef DEBUG 102 #define _DEBUG 1 103 #else 104 #define _DEBUG 0 105 #endif 106 107 #ifdef CONFIG_SPL_BUILD 108 #define _SPL_BUILD 1 109 #else 110 #define _SPL_BUILD 0 111 #endif 112 113 #if !_DEBUG && CONFIG_IS_ENABLED(LOG) 114 115 #define debug_cond(cond, fmt, args...) \ 116 do { \ 117 if (1) \ 118 log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \ 119 } while (0) 120 121 #else /* _DEBUG */ 122 123 /* 124 * Output a debug text when condition "cond" is met. The "cond" should be 125 * computed by a preprocessor in the best case, allowing for the best 126 * optimization. 127 */ 128 #define debug_cond(cond, fmt, args...) \ 129 do { \ 130 if (cond) \ 131 printf(pr_fmt(fmt), ##args); \ 132 } while (0) 133 134 #endif /* _DEBUG */ 135 136 /* Show a message if DEBUG is defined in a file */ 137 #define debug(fmt, args...) \ 138 debug_cond(_DEBUG, fmt, ##args) 139 140 /* Show a message if not in SPL */ 141 #define warn_non_spl(fmt, args...) \ 142 debug_cond(!_SPL_BUILD, fmt, ##args) 143 144 /* 145 * An assertion is run-time check done in debug mode only. If DEBUG is not 146 * defined then it is skipped. If DEBUG is defined and the assertion fails, 147 * then it calls panic*( which may or may not reset/halt U-Boot (see 148 * CONFIG_PANIC_HANG), It is hoped that all failing assertions are found 149 * before release, and after release it is hoped that they don't matter. But 150 * in any case these failing assertions cannot be fixed with a reset (which 151 * may just do the same assertion again). 152 */ 153 void __assert_fail(const char *assertion, const char *file, unsigned int line, 154 const char *function); 155 #define assert(x) \ 156 ({ if (!(x) && _DEBUG) \ 157 __assert_fail(#x, __FILE__, __LINE__, __func__); }) 158 159 /** 160 * struct log_rec - a single log record 161 * 162 * Holds information about a single record in the log 163 * 164 * Members marked as 'not allocated' are stored as pointers and the caller is 165 * responsible for making sure that the data pointed to is not overwritten. 166 * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log 167 * system. 168 * 169 * @cat: Category, representing a uclass or part of U-Boot 170 * @level: Severity level, less severe is higher 171 * @file: Name of file where the log record was generated (not allocated) 172 * @line: Line number where the log record was generated 173 * @func: Function where the log record was generated (not allocated) 174 * @msg: Log message (allocated) 175 */ 176 struct log_rec { 177 enum log_category_t cat; 178 enum log_level_t level; 179 const char *file; 180 int line; 181 const char *func; 182 const char *msg; 183 }; 184 185 struct log_device; 186 187 /** 188 * struct log_driver - a driver which accepts and processes log records 189 * 190 * @name: Name of driver 191 */ 192 struct log_driver { 193 const char *name; 194 /** 195 * emit() - emit a log record 196 * 197 * Called by the log system to pass a log record to a particular driver 198 * for processing. The filter is checked before calling this function. 199 */ 200 int (*emit)(struct log_device *ldev, struct log_rec *rec); 201 }; 202 203 /** 204 * struct log_device - an instance of a log driver 205 * 206 * Since drivers are set up at build-time we need to have a separate device for 207 * the run-time aspects of drivers (currently just a list of filters to apply 208 * to records send to this device). 209 * 210 * @next_filter_num: Seqence number of next filter filter added (0=no filters 211 * yet). This increments with each new filter on the device, but never 212 * decrements 213 * @drv: Pointer to driver for this device 214 * @filter_head: List of filters for this device 215 * @sibling_node: Next device in the list of all devices 216 */ 217 struct log_device { 218 int next_filter_num; 219 struct log_driver *drv; 220 struct list_head filter_head; 221 struct list_head sibling_node; 222 }; 223 224 enum { 225 LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */ 226 }; 227 228 enum log_filter_flags { 229 LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */ 230 }; 231 232 /** 233 * struct log_filter - criterial to filter out log messages 234 * 235 * @filter_num: Sequence number of this filter. This is returned when adding a 236 * new filter, and must be provided when removing a previously added 237 * filter. 238 * @flags: Flags for this filter (LOGFF_...) 239 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty 240 * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries 241 * can be provided 242 * @max_level: Maximum log level to allow 243 * @file_list: List of files to allow, separated by comma. If NULL then all 244 * files are permitted 245 * @sibling_node: Next filter in the list of filters for this log device 246 */ 247 struct log_filter { 248 int filter_num; 249 int flags; 250 enum log_category_t cat_list[LOGF_MAX_CATEGORIES]; 251 enum log_level_t max_level; 252 const char *file_list; 253 struct list_head sibling_node; 254 }; 255 256 #define LOG_DRIVER(_name) \ 257 ll_entry_declare(struct log_driver, _name, log_driver) 258 259 /* Handle the 'log test' command */ 260 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]); 261 262 /** 263 * log_add_filter() - Add a new filter to a log device 264 * 265 * @drv_name: Driver name to add the filter to (since each driver only has a 266 * single device) 267 * @cat_list: List of categories to allow (terminated by LOGC_none). If empty 268 * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries 269 * can be provided 270 * @max_level: Maximum log level to allow 271 * @file_list: List of files to allow, separated by comma. If NULL then all 272 * files are permitted 273 * @return the sequence number of the new filter (>=0) if the filter was added, 274 * or a -ve value on error 275 */ 276 int log_add_filter(const char *drv_name, enum log_category_t cat_list[], 277 enum log_level_t max_level, const char *file_list); 278 279 /** 280 * log_remove_filter() - Remove a filter from a log device 281 * 282 * @drv_name: Driver name to remove the filter from (since each driver only has 283 * a single device) 284 * @filter_num: Filter number to remove (as returned by log_add_filter()) 285 * @return 0 if the filter was removed, -ENOENT if either the driver or the 286 * filter number was not found 287 */ 288 int log_remove_filter(const char *drv_name, int filter_num); 289 290 #if CONFIG_IS_ENABLED(LOG) 291 /** 292 * log_init() - Set up the log system ready for use 293 * 294 * @return 0 if OK, -ENOMEM if out of memory 295 */ 296 int log_init(void); 297 #else 298 static inline int log_init(void) 299 { 300 return 0; 301 } 302 #endif 303 304 #endif 305