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 <linux/log2.h>
  17 #include <asm/byteorder.h>
  18 #include <asm/bug.h>
  19
  20 extern const char linux_banner[];
  21 extern const char linux_proc_banner[];
  22
  23 #define INT_MAX         ((int)(~0U>>1))
  24 #define INT_MIN         (-INT_MAX - 1)
  25 #define UINT_MAX        (~0U)
  26 #define LONG_MAX        ((long)(~0UL>>1))
  27 #define LONG_MIN        (-LONG_MAX - 1)
  28 #define ULONG_MAX       (~0UL)
  29 #define LLONG_MAX       ((long long)(~0ULL>>1))
  30 #define LLONG_MIN       (-LLONG_MAX - 1)
  31 #define ULLONG_MAX      (~0ULL)
  32
  33 #define STACK_MAGIC     0xdeadbeef
  34
  35 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  36 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  37
  38 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  39
  40 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  41 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  42 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  43
  44 /**
  45  * upper_32_bits - return bits 32-63 of a number
  46  * @n: the number we're accessing
  47  *
  48  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  49  * the "right shift count >= width of type" warning when that quantity is
  50  * 32-bits.
  51  */
  52 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  53
  54 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  55 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  56 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  57 #define KERN_ERR        "<3>"   /* error conditions                     */
  58 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  59 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  60 #define KERN_INFO       "<6>"   /* informational                        */
  61 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  62
  63 extern int console_printk[];
  64
  65 #define console_loglevel (console_printk[0])
  66 #define default_message_loglevel (console_printk[1])
  67 #define minimum_console_loglevel (console_printk[2])
  68 #define default_console_loglevel (console_printk[3])
  69
  70 struct completion;
  71 struct pt_regs;
  72 struct user;
  73
  74 /**
  75  * might_sleep - annotation for functions that can sleep
  76  *
  77  * this macro will print a stack trace if it is executed in an atomic
  78  * context (spinlock, irq-handler, ...).
  79  *
  80  * This is a useful debugging help to be able to catch problems early and not
  81  * be bitten later when the calling function happens to sleep when it is not
  82  * supposed to.
  83  */
  84 #ifdef CONFIG_PREEMPT_VOLUNTARY
  85 extern int cond_resched(void);
  86 # define might_resched() cond_resched()
  87 #else
  88 # define might_resched() do { } while (0)
  89 #endif
  90
  91 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
  92   void __might_sleep(char *file, int line);
  93 # define might_sleep() \
  94         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
  95 #else
  96 # define might_sleep() do { might_resched(); } while (0)
  97 #endif
  98
  99 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 100
 101 #define abs(x) ({                               \
 102                 int __x = (x);                  \
 103                 (__x < 0) ? -__x : __x;         \
 104         })
 105
 106 extern struct atomic_notifier_head panic_notifier_list;
 107 extern long (*panic_blink)(long time);
 108 NORET_TYPE void panic(const char * fmt, ...)
 109         __attribute__ ((NORET_AND format (printf, 1, 2)));
 110 extern void oops_enter(void);
 111 extern void oops_exit(void);
 112 extern int oops_may_print(void);
 113 fastcall NORET_TYPE void do_exit(long error_code)
 114         ATTRIB_NORET;
 115 NORET_TYPE void complete_and_exit(struct completion *, long)
 116         ATTRIB_NORET;
 117 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 118 extern long simple_strtol(const char *,char **,unsigned int);
 119 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 120 extern long long simple_strtoll(const char *,char **,unsigned int);
 121 extern int sprintf(char * buf, const char * fmt, ...)
 122         __attribute__ ((format (printf, 2, 3)));
 123 extern int vsprintf(char *buf, const char *, va_list)
 124         __attribute__ ((format (printf, 2, 0)));
 125 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 126         __attribute__ ((format (printf, 3, 4)));
 127 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 128         __attribute__ ((format (printf, 3, 0)));
 129 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 130         __attribute__ ((format (printf, 3, 4)));
 131 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 132         __attribute__ ((format (printf, 3, 0)));
 133 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 134         __attribute__ ((format (printf, 2, 3)));
 135 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 136
 137 extern int sscanf(const char *, const char *, ...)
 138         __attribute__ ((format (scanf, 2, 3)));
 139 extern int vsscanf(const char *, const char *, va_list)
 140         __attribute__ ((format (scanf, 2, 0)));
 141
 142 extern int get_option(char **str, int *pint);
 143 extern char *get_options(const char *str, int nints, int *ints);
 144 extern unsigned long long memparse(char *ptr, char **retptr);
 145
 146 extern int core_kernel_text(unsigned long addr);
 147 extern int __kernel_text_address(unsigned long addr);
 148 extern int kernel_text_address(unsigned long addr);
 149 struct pid;
 150 extern struct pid *session_of_pgrp(struct pid *pgrp);
 151
 152 extern void dump_thread(struct pt_regs *regs, struct user *dump);
 153
 154 #ifdef CONFIG_PRINTK
 155 asmlinkage int vprintk(const char *fmt, va_list args)
 156         __attribute__ ((format (printf, 1, 0)));
 157 asmlinkage int printk(const char * fmt, ...)
 158         __attribute__ ((format (printf, 1, 2)));
 159 #else
 160 static inline int vprintk(const char *s, va_list args)
 161         __attribute__ ((format (printf, 1, 0)));
 162 static inline int vprintk(const char *s, va_list args) { return 0; }
 163 static inline int printk(const char *s, ...)
 164         __attribute__ ((format (printf, 1, 2)));
 165 static inline int printk(const char *s, ...) { return 0; }
 166 #endif
 167
 168 unsigned long int_sqrt(unsigned long);
 169
 170 extern int printk_ratelimit(void);
 171 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 172 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 173                                 unsigned int interval_msec);
 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 void wake_up_klogd(void);
 188 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 189 extern int panic_timeout;
 190 extern int panic_on_oops;
 191 extern int panic_on_unrecovered_nmi;
 192 extern int tainted;
 193 extern const char *print_tainted(void);
 194 extern void add_taint(unsigned);
 195
 196 /* Values used for system_state */
 197 extern enum system_states {
 198         SYSTEM_BOOTING,
 199         SYSTEM_RUNNING,
 200         SYSTEM_HALT,
 201         SYSTEM_POWER_OFF,
 202         SYSTEM_RESTART,
 203         SYSTEM_SUSPEND_DISK,
 204 } system_state;
 205
 206 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 207 #define TAINT_FORCED_MODULE             (1<<1)
 208 #define TAINT_UNSAFE_SMP                (1<<2)
 209 #define TAINT_FORCED_RMMOD              (1<<3)
 210 #define TAINT_MACHINE_CHECK             (1<<4)
 211 #define TAINT_BAD_PAGE                  (1<<5)
 212 #define TAINT_USER                      (1<<6)
 213
 214 extern void dump_stack(void);
 215
 216 enum {
 217         DUMP_PREFIX_NONE,
 218         DUMP_PREFIX_ADDRESS,
 219         DUMP_PREFIX_OFFSET
 220 };
 221 extern void hex_dump_to_buffer(const void *buf, size_t len, char *linebuf,
 222                                 size_t linebuflen);
 223 extern void print_hex_dump(const char *level, int prefix_type,
 224                                 void *buf, size_t len);
 225 #define hex_asc(x)      "0123456789abcdef"[x]
 226
 227 #ifdef DEBUG
 228 /* If you are writing a driver, please use dev_dbg instead */
 229 #define pr_debug(fmt,arg...) \
 230         printk(KERN_DEBUG fmt,##arg)
 231 #else
 232 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
 233 {
 234         return 0;
 235 }
 236 #endif
 237
 238 #define pr_info(fmt,arg...) \
 239         printk(KERN_INFO fmt,##arg)
 240
 241 /*
 242  *      Display an IP address in readable format.
 243  */
 244
 245 #define NIPQUAD(addr) \
 246         ((unsigned char *)&addr)[0], \
 247         ((unsigned char *)&addr)[1], \
 248         ((unsigned char *)&addr)[2], \
 249         ((unsigned char *)&addr)[3]
 250 #define NIPQUAD_FMT "%u.%u.%u.%u"
 251
 252 #define NIP6(addr) \
 253         ntohs((addr).s6_addr16[0]), \
 254         ntohs((addr).s6_addr16[1]), \
 255         ntohs((addr).s6_addr16[2]), \
 256         ntohs((addr).s6_addr16[3]), \
 257         ntohs((addr).s6_addr16[4]), \
 258         ntohs((addr).s6_addr16[5]), \
 259         ntohs((addr).s6_addr16[6]), \
 260         ntohs((addr).s6_addr16[7])
 261 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 262 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 263
 264 #if defined(__LITTLE_ENDIAN)
 265 #define HIPQUAD(addr) \
 266         ((unsigned char *)&addr)[3], \
 267         ((unsigned char *)&addr)[2], \
 268         ((unsigned char *)&addr)[1], \
 269         ((unsigned char *)&addr)[0]
 270 #elif defined(__BIG_ENDIAN)
 271 #define HIPQUAD NIPQUAD
 272 #else
 273 #error "Please fix asm/byteorder.h"
 274 #endif /* __LITTLE_ENDIAN */
 275
 276 /*
 277  * min()/max() macros that also do
 278  * strict type-checking.. See the
 279  * "unnecessary" pointer comparison.
 280  */
 281 #define min(x,y) ({ \
 282         typeof(x) _x = (x);     \
 283         typeof(y) _y = (y);     \
 284         (void) (&_x == &_y);            \
 285         _x < _y ? _x : _y; })
 286
 287 #define max(x,y) ({ \
 288         typeof(x) _x = (x);     \
 289         typeof(y) _y = (y);     \
 290         (void) (&_x == &_y);            \
 291         _x > _y ? _x : _y; })
 292
 293 /*
 294  * ..and if you can't take the strict
 295  * types, you can specify one yourself.
 296  *
 297  * Or not use min/max at all, of course.
 298  */
 299 #define min_t(type,x,y) \
 300         ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 301 #define max_t(type,x,y) \
 302         ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 303
 304
 305 /**
 306  * container_of - cast a member of a structure out to the containing structure
 307  * @ptr:        the pointer to the member.
 308  * @type:       the type of the container struct this is embedded in.
 309  * @member:     the name of the member within the struct.
 310  *
 311  */
 312 #define container_of(ptr, type, member) ({                      \
 313         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 314         (type *)( (char *)__mptr - offsetof(type,member) );})
 315
 316 /*
 317  * Check at compile time that something is of a particular type.
 318  * Always evaluates to 1 so you may use it easily in comparisons.
 319  */
 320 #define typecheck(type,x) \
 321 ({      type __dummy; \
 322         typeof(x) __dummy2; \
 323         (void)(&__dummy == &__dummy2); \
 324         1; \
 325 })
 326
 327 /*
 328  * Check at compile time that 'function' is a certain type, or is a pointer
 329  * to that type (needs to use typedef for the function type.)
 330  */
 331 #define typecheck_fn(type,function) \
 332 ({      typeof(type) __tmp = function; \
 333         (void)__tmp; \
 334 })
 335
 336 struct sysinfo;
 337 extern int do_sysinfo(struct sysinfo *info);
 338
 339 #endif /* __KERNEL__ */
 340
 341 #define SI_LOAD_SHIFT   16
 342 struct sysinfo {
 343         long uptime;                    /* Seconds since boot */
 344         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 345         unsigned long totalram;         /* Total usable main memory size */
 346         unsigned long freeram;          /* Available memory size */
 347         unsigned long sharedram;        /* Amount of shared memory */
 348         unsigned long bufferram;        /* Memory used by buffers */
 349         unsigned long totalswap;        /* Total swap space size */
 350         unsigned long freeswap;         /* swap space still available */
 351         unsigned short procs;           /* Number of current processes */
 352         unsigned short pad;             /* explicit padding for m68k */
 353         unsigned long totalhigh;        /* Total high memory size */
 354         unsigned long freehigh;         /* Available high memory size */
 355         unsigned int mem_unit;          /* Memory unit size in bytes */
 356         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 357 };
 358
 359 /* Force a compilation error if condition is true */
 360 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 361
 362 /* Force a compilation error if condition is true, but also produce a
 363    result (of value 0 and type size_t), so the expression can be used
 364    e.g. in a structure initializer (or where-ever else comma expressions
 365    aren't permitted). */
 366 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 367
 368 /* Trap pasters of __FUNCTION__ at compile-time */
 369 #define __FUNCTION__ (__func__)
 370
 371 /* This helps us to avoid #ifdef CONFIG_NUMA */
 372 #ifdef CONFIG_NUMA
 373 #define NUMA_BUILD 1
 374 #else
 375 #define NUMA_BUILD 0
 376 #endif
 377
 378 #endif