include/linux/dynamic_printk.h

   1 #ifndef _DYNAMIC_PRINTK_H
   2 #define _DYNAMIC_PRINTK_H
   3
   4 #define DYNAMIC_DEBUG_HASH_BITS 6
   5 #define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS)
   6
   7 #define TYPE_BOOLEAN 1
   8
   9 #define DYNAMIC_ENABLED_ALL 0
  10 #define DYNAMIC_ENABLED_NONE 1
  11 #define DYNAMIC_ENABLED_SOME 2
  12
  13 extern int dynamic_enabled;
  14
  15 /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
  16  * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
  17  * use independent hash functions, to reduce the chance of false positives.
  18  */
  19 extern long long dynamic_printk_enabled;
  20 extern long long dynamic_printk_enabled2;
  21
  22 struct mod_debug {
  23         char *modname;
  24         char *logical_modname;
  25         char *flag_names;
  26         int type;
  27         int hash;
  28         int hash2;
  29 } __attribute__((aligned(8)));
  30
  31 int register_dynamic_debug_module(char *mod_name, int type, char *share_name,
  32                                         char *flags, int hash, int hash2);
  33
  34 #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
  35 extern int unregister_dynamic_debug_module(char *mod_name);
  36 extern int __dynamic_dbg_enabled_helper(char *modname, int type,
  37                                         int value, int hash);
  38
  39 #define __dynamic_dbg_enabled(module, type, value, level, hash)  ({          \
  40         int __ret = 0;                                                       \
  41         if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) &&       \
  42                         (dynamic_printk_enabled2 & (1LL << DEBUG_HASH2))))   \
  43                         __ret = __dynamic_dbg_enabled_helper(module, type,   \
  44                                                                 value, hash);\
  45         __ret; })
  46
  47 #define dynamic_pr_debug(fmt, ...) do {                                     \
  48         static char mod_name[]                                              \
  49         __attribute__((section("__verbose_strings")))                       \
  50          = KBUILD_MODNAME;                                                  \
  51         static struct mod_debug descriptor                                  \
  52         __used                                                              \
  53         __attribute__((section("__verbose"), aligned(8))) =                 \
  54         { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
  55         if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN,             \
  56                                                 0, 0, DEBUG_HASH))          \
  57                 printk(KERN_DEBUG KBUILD_MODNAME ":" fmt,                   \
  58                                 ##__VA_ARGS__);                             \
  59         } while (0)
  60
  61 #define dynamic_dev_dbg(dev, format, ...) do {                              \
  62         static char mod_name[]                                              \
  63         __attribute__((section("__verbose_strings")))                       \
  64          = KBUILD_MODNAME;                                                  \
  65         static struct mod_debug descriptor                                  \
  66         __used                                                              \
  67         __attribute__((section("__verbose"), aligned(8))) =                 \
  68         { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
  69         if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN,             \
  70                                                 0, 0, DEBUG_HASH))          \
  71                         dev_printk(KERN_DEBUG, dev,                         \
  72                                         KBUILD_MODNAME ": " format,         \
  73                                         ##__VA_ARGS__);                     \
  74         } while (0)
  75
  76 #else
  77
  78 static inline int unregister_dynamic_debug_module(const char *mod_name)
  79 {
  80         return 0;
  81 }
  82 static inline int __dynamic_dbg_enabled_helper(char *modname, int type,
  83                                                 int value, int hash)
  84 {
  85         return 0;
  86 }
  87
  88 #define __dynamic_dbg_enabled(module, type, value, level, hash)  ({ 0; })
  89 #define dynamic_pr_debug(fmt, ...)  do { } while (0)
  90 #define dynamic_dev_dbg(dev, format, ...)  do { } while (0)
  91 #endif
  92
  93 #endif