include/linux/kernel.h

   1 #ifndef _LINUX_KERNEL_H
   2 #define _LINUX_KERNEL_H
   3
   4 /*
   5  * 'kernel.h' contains some often-used function prototypes etc
   6  */
   7
   8 #ifdef __KERNEL__
   9
  10 #include <stdarg.h>
  11 #include <linux/linkage.h>
  12 #include <linux/stddef.h>
  13 #include <linux/types.h>
  14 #include <linux/compiler.h>
  15 #include <linux/bitops.h>
  16 #include <asm/byteorder.h>
  17 #include <asm/bug.h>
  18
  19 extern const char linux_banner[];
  20
  21 #define INT_MAX         ((int)(~0U>>1))
  22 #define INT_MIN         (-INT_MAX - 1)
  23 #define UINT_MAX        (~0U)
  24 #define LONG_MAX        ((long)(~0UL>>1))
  25 #define LONG_MIN        (-LONG_MAX - 1)
  26 #define ULONG_MAX       (~0UL)
  27 #define LLONG_MAX       ((long long)(~0ULL>>1))
  28 #define LLONG_MIN       (-LLONG_MAX - 1)
  29 #define ULLONG_MAX      (~0ULL)
  30
  31 #define STACK_MAGIC     0xdeadbeef
  32
  33 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  34 #define ALIGN(x,a) (((x)+(a)-1UL)&~((a)-1UL))
  35 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  36 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  37 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  38
  39 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  40 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  41 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  42 #define KERN_ERR        "<3>"   /* error conditions                     */
  43 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  44 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  45 #define KERN_INFO       "<6>"   /* informational                        */
  46 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  47
  48 extern int console_printk[];
  49
  50 #define console_loglevel (console_printk[0])
  51 #define default_message_loglevel (console_printk[1])
  52 #define minimum_console_loglevel (console_printk[2])
  53 #define default_console_loglevel (console_printk[3])
  54
  55 struct completion;
  56 struct pt_regs;
  57 struct user;
  58
  59 /**
  60  * might_sleep - annotation for functions that can sleep
  61  *
  62  * this macro will print a stack trace if it is executed in an atomic
  63  * context (spinlock, irq-handler, ...).
  64  *
  65  * This is a useful debugging help to be able to catch problems early and not
  66  * be biten later when the calling function happens to sleep when it is not
  67  * supposed to.
  68  */
  69 #ifdef CONFIG_PREEMPT_VOLUNTARY
  70 extern int cond_resched(void);
  71 # define might_resched() cond_resched()
  72 #else
  73 # define might_resched() do { } while (0)
  74 #endif
  75
  76 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
  77   void __might_sleep(char *file, int line);
  78 # define might_sleep() \
  79         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
  80 #else
  81 # define might_sleep() do { might_resched(); } while (0)
  82 #endif
  83
  84 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  85
  86 #define abs(x) ({                               \
  87                 int __x = (x);                  \
  88                 (__x < 0) ? -__x : __x;         \
  89         })
  90
  91 #define labs(x) ({                              \
  92                 long __x = (x);                 \
  93                 (__x < 0) ? -__x : __x;         \
  94         })
  95
  96 extern struct atomic_notifier_head panic_notifier_list;
  97 extern long (*panic_blink)(long time);
  98 NORET_TYPE void panic(const char * fmt, ...)
  99         __attribute__ ((NORET_AND format (printf, 1, 2)));
 100 extern void oops_enter(void);
 101 extern void oops_exit(void);
 102 extern int oops_may_print(void);
 103 fastcall NORET_TYPE void do_exit(long error_code)
 104         ATTRIB_NORET;
 105 NORET_TYPE void complete_and_exit(struct completion *, long)
 106         ATTRIB_NORET;
 107 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 108 extern long simple_strtol(const char *,char **,unsigned int);
 109 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 110 extern long long simple_strtoll(const char *,char **,unsigned int);
 111 extern int sprintf(char * buf, const char * fmt, ...)
 112         __attribute__ ((format (printf, 2, 3)));
 113 extern int vsprintf(char *buf, const char *, va_list)
 114         __attribute__ ((format (printf, 2, 0)));
 115 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 116         __attribute__ ((format (printf, 3, 4)));
 117 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 118         __attribute__ ((format (printf, 3, 0)));
 119 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 120         __attribute__ ((format (printf, 3, 4)));
 121 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 122         __attribute__ ((format (printf, 3, 0)));
 123 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 124         __attribute__ ((format (printf, 2, 3)));
 125
 126 extern int sscanf(const char *, const char *, ...)
 127         __attribute__ ((format (scanf, 2, 3)));
 128 extern int vsscanf(const char *, const char *, va_list)
 129         __attribute__ ((format (scanf, 2, 0)));
 130
 131 extern int get_option(char **str, int *pint);
 132 extern char *get_options(const char *str, int nints, int *ints);
 133 extern unsigned long long memparse(char *ptr, char **retptr);
 134
 135 extern int core_kernel_text(unsigned long addr);
 136 extern int __kernel_text_address(unsigned long addr);
 137 extern int kernel_text_address(unsigned long addr);
 138 extern int session_of_pgrp(int pgrp);
 139
 140 extern void dump_thread(struct pt_regs *regs, struct user *dump);
 141
 142 #ifdef CONFIG_PRINTK
 143 asmlinkage int vprintk(const char *fmt, va_list args)
 144         __attribute__ ((format (printf, 1, 0)));
 145 asmlinkage int printk(const char * fmt, ...)
 146         __attribute__ ((format (printf, 1, 2)));
 147 #else
 148 static inline int vprintk(const char *s, va_list args)
 149         __attribute__ ((format (printf, 1, 0)));
 150 static inline int vprintk(const char *s, va_list args) { return 0; }
 151 static inline int printk(const char *s, ...)
 152         __attribute__ ((format (printf, 1, 2)));
 153 static inline int printk(const char *s, ...) { return 0; }
 154 #endif
 155
 156 unsigned long int_sqrt(unsigned long);
 157
 158 static inline int __attribute_pure__ long_log2(unsigned long x)
 159 {
 160         int r = 0;
 161         for (x >>= 1; x > 0; x >>= 1)
 162                 r++;
 163         return r;
 164 }
 165
 166 static inline unsigned long
 167 __attribute_const__ roundup_pow_of_two(unsigned long x)
 168 {
 169         return 1UL << fls_long(x - 1);
 170 }
 171
 172 extern int printk_ratelimit(void);
 173 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 174
 175 static inline void console_silent(void)
 176 {
 177         console_loglevel = 0;
 178 }
 179
 180 static inline void console_verbose(void)
 181 {
 182         if (console_loglevel)
 183                 console_loglevel = 15;
 184 }
 185
 186 extern void bust_spinlocks(int yes);
 187 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 188 extern int panic_timeout;
 189 extern int panic_on_oops;
 190 extern int panic_on_unrecovered_nmi;
 191 extern int tainted;
 192 extern const char *print_tainted(void);
 193 extern void add_taint(unsigned);
 194
 195 /* Values used for system_state */
 196 extern enum system_states {
 197         SYSTEM_BOOTING,
 198         SYSTEM_RUNNING,
 199         SYSTEM_HALT,
 200         SYSTEM_POWER_OFF,
 201         SYSTEM_RESTART,
 202         SYSTEM_SUSPEND_DISK,
 203 } system_state;
 204
 205 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 206 #define TAINT_FORCED_MODULE             (1<<1)
 207 #define TAINT_UNSAFE_SMP                (1<<2)
 208 #define TAINT_FORCED_RMMOD              (1<<3)
 209 #define TAINT_MACHINE_CHECK             (1<<4)
 210 #define TAINT_BAD_PAGE                  (1<<5)
 211
 212 extern void dump_stack(void);
 213
 214 #ifdef DEBUG
 215 /* If you are writing a driver, please use dev_dbg instead */
 216 #define pr_debug(fmt,arg...) \
 217         printk(KERN_DEBUG fmt,##arg)
 218 #else
 219 #define pr_debug(fmt,arg...) \
 220         do { } while (0)
 221 #endif
 222
 223 #define pr_info(fmt,arg...) \
 224         printk(KERN_INFO fmt,##arg)
 225
 226 /*
 227  *      Display an IP address in readable format.
 228  */
 229
 230 #define NIPQUAD(addr) \
 231         ((unsigned char *)&addr)[0], \
 232         ((unsigned char *)&addr)[1], \
 233         ((unsigned char *)&addr)[2], \
 234         ((unsigned char *)&addr)[3]
 235 #define NIPQUAD_FMT "%u.%u.%u.%u"
 236
 237 #define NIP6(addr) \
 238         ntohs((addr).s6_addr16[0]), \
 239         ntohs((addr).s6_addr16[1]), \
 240         ntohs((addr).s6_addr16[2]), \
 241         ntohs((addr).s6_addr16[3]), \
 242         ntohs((addr).s6_addr16[4]), \
 243         ntohs((addr).s6_addr16[5]), \
 244         ntohs((addr).s6_addr16[6]), \
 245         ntohs((addr).s6_addr16[7])
 246 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 247 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 248
 249 #if defined(__LITTLE_ENDIAN)
 250 #define HIPQUAD(addr) \
 251         ((unsigned char *)&addr)[3], \
 252         ((unsigned char *)&addr)[2], \
 253         ((unsigned char *)&addr)[1], \
 254         ((unsigned char *)&addr)[0]
 255 #elif defined(__BIG_ENDIAN)
 256 #define HIPQUAD NIPQUAD
 257 #else
 258 #error "Please fix asm/byteorder.h"
 259 #endif /* __LITTLE_ENDIAN */
 260
 261 /*
 262  * min()/max() macros that also do
 263  * strict type-checking.. See the
 264  * "unnecessary" pointer comparison.
 265  */
 266 #define min(x,y) ({ \
 267         typeof(x) _x = (x);     \
 268         typeof(y) _y = (y);     \
 269         (void) (&_x == &_y);            \
 270         _x < _y ? _x : _y; })
 271
 272 #define max(x,y) ({ \
 273         typeof(x) _x = (x);     \
 274         typeof(y) _y = (y);     \
 275         (void) (&_x == &_y);            \
 276         _x > _y ? _x : _y; })
 277
 278 /*
 279  * ..and if you can't take the strict
 280  * types, you can specify one yourself.
 281  *
 282  * Or not use min/max at all, of course.
 283  */
 284 #define min_t(type,x,y) \
 285         ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 286 #define max_t(type,x,y) \
 287         ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 288
 289
 290 /**
 291  * container_of - cast a member of a structure out to the containing structure
 292  * @ptr:        the pointer to the member.
 293  * @type:       the type of the container struct this is embedded in.
 294  * @member:     the name of the member within the struct.
 295  *
 296  */
 297 #define container_of(ptr, type, member) ({                      \
 298         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 299         (type *)( (char *)__mptr - offsetof(type,member) );})
 300
 301 /*
 302  * Check at compile time that something is of a particular type.
 303  * Always evaluates to 1 so you may use it easily in comparisons.
 304  */
 305 #define typecheck(type,x) \
 306 ({      type __dummy; \
 307         typeof(x) __dummy2; \
 308         (void)(&__dummy == &__dummy2); \
 309         1; \
 310 })
 311
 312 /*
 313  * Check at compile time that 'function' is a certain type, or is a pointer
 314  * to that type (needs to use typedef for the function type.)
 315  */
 316 #define typecheck_fn(type,function) \
 317 ({      typeof(type) __tmp = function; \
 318         (void)__tmp; \
 319 })
 320
 321 #endif /* __KERNEL__ */
 322
 323 #define SI_LOAD_SHIFT   16
 324 struct sysinfo {
 325         long uptime;                    /* Seconds since boot */
 326         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 327         unsigned long totalram;         /* Total usable main memory size */
 328         unsigned long freeram;          /* Available memory size */
 329         unsigned long sharedram;        /* Amount of shared memory */
 330         unsigned long bufferram;        /* Memory used by buffers */
 331         unsigned long totalswap;        /* Total swap space size */
 332         unsigned long freeswap;         /* swap space still available */
 333         unsigned short procs;           /* Number of current processes */
 334         unsigned short pad;             /* explicit padding for m68k */
 335         unsigned long totalhigh;        /* Total high memory size */
 336         unsigned long freehigh;         /* Available high memory size */
 337         unsigned int mem_unit;          /* Memory unit size in bytes */
 338         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 339 };
 340
 341 /* Force a compilation error if condition is true */
 342 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 343
 344 /* Force a compilation error if condition is true, but also produce a
 345    result (of value 0 and type size_t), so the expression can be used
 346    e.g. in a structure initializer (or where-ever else comma expressions
 347    aren't permitted). */
 348 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 349
 350 /* Trap pasters of __FUNCTION__ at compile-time */
 351 #define __FUNCTION__ (__func__)
 352
 353 /* This helps us to avoid #ifdef CONFIG_NUMA */
 354 #ifdef CONFIG_NUMA
 355 #define NUMA_BUILD 1
 356 #else
 357 #define NUMA_BUILD 0
 358 #endif
 359
 360 #endif