include/log.h

   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 */
  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
 187 /**
 188  * assert() - assert expression is true
 189  *
 190  * If the expression x evaluates to false and _DEBUG evaluates to true, a panic
 191  * message is written and the system stalls. The value of _DEBUG is set to true
 192  * if DEBUG is defined before including common.h.
 193  *
 194  * The expression x is always executed irrespective of the value of _DEBUG.
 195  *
 196  * @x:          expression to test
 197  */
 198 #define assert(x) \
 199         ({ if (!(x) && _DEBUG) \
 200                 __assert_fail(#x, __FILE__, __LINE__, __func__); })
 201
 202 #if CONFIG_IS_ENABLED(LOG) && defined(CONFIG_LOG_ERROR_RETURN)
 203 /*
 204  * Log an error return value, possibly with a message. Usage:
 205  *
 206  *      return log_ret(fred_call());
 207  *
 208  * or:
 209  *
 210  *      return log_msg_ret("fred failed", fred_call());
 211  */
 212 #define log_ret(_ret) ({ \
 213         int __ret = (_ret); \
 214         if (__ret < 0) \
 215                 log(LOG_CATEGORY, LOGL_ERR, "returning err=%d\n", __ret); \
 216         __ret; \
 217         })
 218 #define log_msg_ret(_msg, _ret) ({ \
 219         int __ret = (_ret); \
 220         if (__ret < 0) \
 221                 log(LOG_CATEGORY, LOGL_ERR, "%s: returning err=%d\n", _msg, \
 222                     __ret); \
 223         __ret; \
 224         })
 225 #else
 226 /* Non-logging versions of the above which just return the error code */
 227 #define log_ret(_ret) (_ret)
 228 #define log_msg_ret(_msg, _ret) ((void)(_msg), _ret)
 229 #endif
 230
 231 /**
 232  * struct log_rec - a single log record
 233  *
 234  * Holds information about a single record in the log
 235  *
 236  * Members marked as 'not allocated' are stored as pointers and the caller is
 237  * responsible for making sure that the data pointed to is not overwritten.
 238  * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
 239  * system.
 240  *
 241  * @cat: Category, representing a uclass or part of U-Boot
 242  * @level: Severity level, less severe is higher
 243  * @file: Name of file where the log record was generated (not allocated)
 244  * @line: Line number where the log record was generated
 245  * @func: Function where the log record was generated (not allocated)
 246  * @msg: Log message (allocated)
 247  */
 248 struct log_rec {
 249         enum log_category_t cat;
 250         enum log_level_t level;
 251         const char *file;
 252         int line;
 253         const char *func;
 254         const char *msg;
 255 };
 256
 257 struct log_device;
 258
 259 /**
 260  * struct log_driver - a driver which accepts and processes log records
 261  *
 262  * @name: Name of driver
 263  */
 264 struct log_driver {
 265         const char *name;
 266         /**
 267          * emit() - emit a log record
 268          *
 269          * Called by the log system to pass a log record to a particular driver
 270          * for processing. The filter is checked before calling this function.
 271          */
 272         int (*emit)(struct log_device *ldev, struct log_rec *rec);
 273 };
 274
 275 /**
 276  * struct log_device - an instance of a log driver
 277  *
 278  * Since drivers are set up at build-time we need to have a separate device for
 279  * the run-time aspects of drivers (currently just a list of filters to apply
 280  * to records send to this device).
 281  *
 282  * @next_filter_num: Seqence number of next filter filter added (0=no filters
 283  *      yet). This increments with each new filter on the device, but never
 284  *      decrements
 285  * @drv: Pointer to driver for this device
 286  * @filter_head: List of filters for this device
 287  * @sibling_node: Next device in the list of all devices
 288  */
 289 struct log_device {
 290         int next_filter_num;
 291         struct log_driver *drv;
 292         struct list_head filter_head;
 293         struct list_head sibling_node;
 294 };
 295
 296 enum {
 297         LOGF_MAX_CATEGORIES = 5,        /* maximum categories per filter */
 298 };
 299
 300 enum log_filter_flags {
 301         LOGFF_HAS_CAT           = 1 << 0,       /* Filter has a category list */
 302 };
 303
 304 /**
 305  * struct log_filter - criterial to filter out log messages
 306  *
 307  * @filter_num: Sequence number of this filter.  This is returned when adding a
 308  *      new filter, and must be provided when removing a previously added
 309  *      filter.
 310  * @flags: Flags for this filter (LOGFF_...)
 311  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
 312  *      then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
 313  *      can be provided
 314  * @max_level: Maximum log level to allow
 315  * @file_list: List of files to allow, separated by comma. If NULL then all
 316  *      files are permitted
 317  * @sibling_node: Next filter in the list of filters for this log device
 318  */
 319 struct log_filter {
 320         int filter_num;
 321         int flags;
 322         enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
 323         enum log_level_t max_level;
 324         const char *file_list;
 325         struct list_head sibling_node;
 326 };
 327
 328 #define LOG_DRIVER(_name) \
 329         ll_entry_declare(struct log_driver, _name, log_driver)
 330
 331 /**
 332  * log_get_cat_name() - Get the name of a category
 333  *
 334  * @cat: Category to look up
 335  * @return category name (which may be a uclass driver name) if found, or
 336  *       "<invalid>" if invalid, or "<missing>" if not found
 337  */
 338 const char *log_get_cat_name(enum log_category_t cat);
 339
 340 /**
 341  * log_get_cat_by_name() - Look up a category by name
 342  *
 343  * @name: Name to look up
 344  * @return category ID, or LOGC_NONE if not found
 345  */
 346 enum log_category_t log_get_cat_by_name(const char *name);
 347
 348 /**
 349  * log_get_level_name() - Get the name of a log level
 350  *
 351  * @level: Log level to look up
 352  * @return log level name (in ALL CAPS)
 353  */
 354 const char *log_get_level_name(enum log_level_t level);
 355
 356 /**
 357  * log_get_level_by_name() - Look up a log level by name
 358  *
 359  * @name: Name to look up
 360  * @return log level ID, or LOGL_NONE if not found
 361  */
 362 enum log_level_t log_get_level_by_name(const char *name);
 363
 364 /* Log format flags (bit numbers) for gd->log_fmt. See log_fmt_chars */
 365 enum log_fmt {
 366         LOGF_CAT        = 0,
 367         LOGF_LEVEL,
 368         LOGF_FILE,
 369         LOGF_LINE,
 370         LOGF_FUNC,
 371         LOGF_MSG,
 372
 373         LOGF_COUNT,
 374         LOGF_DEFAULT = (1 << LOGF_FUNC) | (1 << LOGF_MSG),
 375         LOGF_ALL = 0x3f,
 376 };
 377
 378 /* Handle the 'log test' command */
 379 int do_log_test(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
 380
 381 /**
 382  * log_add_filter() - Add a new filter to a log device
 383  *
 384  * @drv_name: Driver name to add the filter to (since each driver only has a
 385  *      single device)
 386  * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
 387  *      then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
 388  *      can be provided
 389  * @max_level: Maximum log level to allow
 390  * @file_list: List of files to allow, separated by comma. If NULL then all
 391  *      files are permitted
 392  * @return the sequence number of the new filter (>=0) if the filter was added,
 393  *      or a -ve value on error
 394  */
 395 int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
 396                    enum log_level_t max_level, const char *file_list);
 397
 398 /**
 399  * log_remove_filter() - Remove a filter from a log device
 400  *
 401  * @drv_name: Driver name to remove the filter from (since each driver only has
 402  *      a single device)
 403  * @filter_num: Filter number to remove (as returned by log_add_filter())
 404  * @return 0 if the filter was removed, -ENOENT if either the driver or the
 405  *      filter number was not found
 406  */
 407 int log_remove_filter(const char *drv_name, int filter_num);
 408
 409 #if CONFIG_IS_ENABLED(LOG)
 410 /**
 411  * log_init() - Set up the log system ready for use
 412  *
 413  * @return 0 if OK, -ENOMEM if out of memory
 414  */
 415 int log_init(void);
 416 #else
 417 static inline int log_init(void)
 418 {
 419         return 0;
 420 }
 421 #endif
 422
 423 #endif