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 <linux/typecheck.h>
  18 #include <asm/byteorder.h>
  19 #include <asm/bug.h>
  20
  21 extern const char linux_banner[];
  22 extern const char linux_proc_banner[];
  23
  24 #define USHORT_MAX      ((u16)(~0U))
  25 #define SHORT_MAX       ((s16)(USHORT_MAX>>1))
  26 #define SHORT_MIN       (-SHORT_MAX - 1)
  27 #define INT_MAX         ((int)(~0U>>1))
  28 #define INT_MIN         (-INT_MAX - 1)
  29 #define UINT_MAX        (~0U)
  30 #define LONG_MAX        ((long)(~0UL>>1))
  31 #define LONG_MIN        (-LONG_MAX - 1)
  32 #define ULONG_MAX       (~0UL)
  33 #define LLONG_MAX       ((long long)(~0ULL>>1))
  34 #define LLONG_MIN       (-LLONG_MAX - 1)
  35 #define ULLONG_MAX      (~0ULL)
  36
  37 #define STACK_MAGIC     0xdeadbeef
  38
  39 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  40 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  41 #define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  42 #define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  43
  44 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  45
  46 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  47 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  48 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  49
  50 #define _RET_IP_                (unsigned long)__builtin_return_address(0)
  51 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
  52
  53 #ifdef CONFIG_LBD
  54 # include <asm/div64.h>
  55 # define sector_div(a, b) do_div(a, b)
  56 #else
  57 # define sector_div(n, b)( \
  58 { \
  59         int _res; \
  60         _res = (n) % (b); \
  61         (n) /= (b); \
  62         _res; \
  63 } \
  64 )
  65 #endif
  66
  67 /**
  68  * upper_32_bits - return bits 32-63 of a number
  69  * @n: the number we're accessing
  70  *
  71  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  72  * the "right shift count >= width of type" warning when that quantity is
  73  * 32-bits.
  74  */
  75 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  76
  77 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  78 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  79 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  80 #define KERN_ERR        "<3>"   /* error conditions                     */
  81 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  82 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  83 #define KERN_INFO       "<6>"   /* informational                        */
  84 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  85
  86 /*
  87  * Annotation for a "continued" line of log printout (only done after a
  88  * line that had no enclosing \n). Only to be used by core/arch code
  89  * during early bootup (a continued line is not SMP-safe otherwise).
  90  */
  91 #define KERN_CONT       ""
  92
  93 extern int console_printk[];
  94
  95 #define console_loglevel (console_printk[0])
  96 #define default_message_loglevel (console_printk[1])
  97 #define minimum_console_loglevel (console_printk[2])
  98 #define default_console_loglevel (console_printk[3])
  99
 100 struct completion;
 101 struct pt_regs;
 102 struct user;
 103
 104 /**
 105  * might_sleep - annotation for functions that can sleep
 106  *
 107  * this macro will print a stack trace if it is executed in an atomic
 108  * context (spinlock, irq-handler, ...).
 109  *
 110  * This is a useful debugging help to be able to catch problems early and not
 111  * be bitten later when the calling function happens to sleep when it is not
 112  * supposed to.
 113  */
 114 #ifdef CONFIG_PREEMPT_VOLUNTARY
 115 extern int _cond_resched(void);
 116 # define might_resched() _cond_resched()
 117 #else
 118 # define might_resched() do { } while (0)
 119 #endif
 120
 121 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 122   void __might_sleep(char *file, int line);
 123 # define might_sleep() \
 124         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 125 #else
 126 # define might_sleep() do { might_resched(); } while (0)
 127 #endif
 128
 129 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 130
 131 #define abs(x) ({                               \
 132                 int __x = (x);                  \
 133                 (__x < 0) ? -__x : __x;         \
 134         })
 135
 136 extern struct atomic_notifier_head panic_notifier_list;
 137 extern long (*panic_blink)(long time);
 138 NORET_TYPE void panic(const char * fmt, ...)
 139         __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 140 extern void oops_enter(void);
 141 extern void oops_exit(void);
 142 extern int oops_may_print(void);
 143 NORET_TYPE void do_exit(long error_code)
 144         ATTRIB_NORET;
 145 NORET_TYPE void complete_and_exit(struct completion *, long)
 146         ATTRIB_NORET;
 147 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 148 extern long simple_strtol(const char *,char **,unsigned int);
 149 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 150 extern long long simple_strtoll(const char *,char **,unsigned int);
 151 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 152 extern int strict_strtol(const char *, unsigned int, long *);
 153 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 154 extern int strict_strtoll(const char *, unsigned int, long long *);
 155 extern int sprintf(char * buf, const char * fmt, ...)
 156         __attribute__ ((format (printf, 2, 3)));
 157 extern int vsprintf(char *buf, const char *, va_list)
 158         __attribute__ ((format (printf, 2, 0)));
 159 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 160         __attribute__ ((format (printf, 3, 4)));
 161 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 162         __attribute__ ((format (printf, 3, 0)));
 163 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 164         __attribute__ ((format (printf, 3, 4)));
 165 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 166         __attribute__ ((format (printf, 3, 0)));
 167 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 168         __attribute__ ((format (printf, 2, 3)));
 169 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 170
 171 extern int sscanf(const char *, const char *, ...)
 172         __attribute__ ((format (scanf, 2, 3)));
 173 extern int vsscanf(const char *, const char *, va_list)
 174         __attribute__ ((format (scanf, 2, 0)));
 175
 176 extern int get_option(char **str, int *pint);
 177 extern char *get_options(const char *str, int nints, int *ints);
 178 extern unsigned long long memparse(char *ptr, char **retptr);
 179
 180 extern int core_kernel_text(unsigned long addr);
 181 extern int __kernel_text_address(unsigned long addr);
 182 extern int kernel_text_address(unsigned long addr);
 183 struct pid;
 184 extern struct pid *session_of_pgrp(struct pid *pgrp);
 185
 186 #ifdef CONFIG_PRINTK
 187 asmlinkage int vprintk(const char *fmt, va_list args)
 188         __attribute__ ((format (printf, 1, 0)));
 189 asmlinkage int printk(const char * fmt, ...)
 190         __attribute__ ((format (printf, 1, 2))) __cold;
 191
 192 extern int printk_ratelimit_jiffies;
 193 extern int printk_ratelimit_burst;
 194 extern int printk_ratelimit(void);
 195 extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 196 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 197 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 198                                    unsigned int interval_msec);
 199 #else
 200 static inline int vprintk(const char *s, va_list args)
 201         __attribute__ ((format (printf, 1, 0)));
 202 static inline int vprintk(const char *s, va_list args) { return 0; }
 203 static inline int printk(const char *s, ...)
 204         __attribute__ ((format (printf, 1, 2)));
 205 static inline int __cold printk(const char *s, ...) { return 0; }
 206 static inline int printk_ratelimit(void) { return 0; }
 207 static inline int __printk_ratelimit(int ratelimit_jiffies, \
 208                                      int ratelimit_burst) { return 0; }
 209 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 210                                           unsigned int interval_msec)   \
 211                 { return false; }
 212 #endif
 213
 214 extern void asmlinkage __attribute__((format(printf, 1, 2)))
 215         early_printk(const char *fmt, ...);
 216
 217 unsigned long int_sqrt(unsigned long);
 218
 219 static inline void console_silent(void)
 220 {
 221         console_loglevel = 0;
 222 }
 223
 224 static inline void console_verbose(void)
 225 {
 226         if (console_loglevel)
 227                 console_loglevel = 15;
 228 }
 229
 230 extern void bust_spinlocks(int yes);
 231 extern void wake_up_klogd(void);
 232 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 233 extern int panic_timeout;
 234 extern int panic_on_oops;
 235 extern int panic_on_unrecovered_nmi;
 236 extern int tainted;
 237 extern const char *print_tainted(void);
 238 extern void add_taint(unsigned);
 239 extern int root_mountflags;
 240
 241 /* Values used for system_state */
 242 extern enum system_states {
 243         SYSTEM_BOOTING,
 244         SYSTEM_RUNNING,
 245         SYSTEM_HALT,
 246         SYSTEM_POWER_OFF,
 247         SYSTEM_RESTART,
 248         SYSTEM_SUSPEND_DISK,
 249 } system_state;
 250
 251 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 252 #define TAINT_FORCED_MODULE             (1<<1)
 253 #define TAINT_UNSAFE_SMP                (1<<2)
 254 #define TAINT_FORCED_RMMOD              (1<<3)
 255 #define TAINT_MACHINE_CHECK             (1<<4)
 256 #define TAINT_BAD_PAGE                  (1<<5)
 257 #define TAINT_USER                      (1<<6)
 258 #define TAINT_DIE                       (1<<7)
 259 #define TAINT_OVERRIDDEN_ACPI_TABLE     (1<<8)
 260 #define TAINT_WARN                      (1<<9)
 261
 262 extern void dump_stack(void) __cold;
 263
 264 enum {
 265         DUMP_PREFIX_NONE,
 266         DUMP_PREFIX_ADDRESS,
 267         DUMP_PREFIX_OFFSET
 268 };
 269 extern void hex_dump_to_buffer(const void *buf, size_t len,
 270                                 int rowsize, int groupsize,
 271                                 char *linebuf, size_t linebuflen, bool ascii);
 272 extern void print_hex_dump(const char *level, const char *prefix_str,
 273                                 int prefix_type, int rowsize, int groupsize,
 274                                 const void *buf, size_t len, bool ascii);
 275 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 276                         const void *buf, size_t len);
 277
 278 extern const char hex_asc[];
 279 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 280 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 281
 282 static inline char *pack_hex_byte(char *buf, u8 byte)
 283 {
 284         *buf++ = hex_asc_hi(byte);
 285         *buf++ = hex_asc_lo(byte);
 286         return buf;
 287 }
 288
 289 #define pr_emerg(fmt, arg...) \
 290         printk(KERN_EMERG fmt, ##arg)
 291 #define pr_alert(fmt, arg...) \
 292         printk(KERN_ALERT fmt, ##arg)
 293 #define pr_crit(fmt, arg...) \
 294         printk(KERN_CRIT fmt, ##arg)
 295 #define pr_err(fmt, arg...) \
 296         printk(KERN_ERR fmt, ##arg)
 297 #define pr_warning(fmt, arg...) \
 298         printk(KERN_WARNING fmt, ##arg)
 299 #define pr_notice(fmt, arg...) \
 300         printk(KERN_NOTICE fmt, ##arg)
 301 #define pr_info(fmt, arg...) \
 302         printk(KERN_INFO fmt, ##arg)
 303
 304 #ifdef DEBUG
 305 /* If you are writing a driver, please use dev_dbg instead */
 306 #define pr_debug(fmt, arg...) \
 307         printk(KERN_DEBUG fmt, ##arg)
 308 #else
 309 #define pr_debug(fmt, arg...) \
 310         ({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
 311 #endif
 312
 313 /*
 314  *      Display an IP address in readable format.
 315  */
 316
 317 #define NIPQUAD(addr) \
 318         ((unsigned char *)&addr)[0], \
 319         ((unsigned char *)&addr)[1], \
 320         ((unsigned char *)&addr)[2], \
 321         ((unsigned char *)&addr)[3]
 322 #define NIPQUAD_FMT "%u.%u.%u.%u"
 323
 324 #define NIP6(addr) \
 325         ntohs((addr).s6_addr16[0]), \
 326         ntohs((addr).s6_addr16[1]), \
 327         ntohs((addr).s6_addr16[2]), \
 328         ntohs((addr).s6_addr16[3]), \
 329         ntohs((addr).s6_addr16[4]), \
 330         ntohs((addr).s6_addr16[5]), \
 331         ntohs((addr).s6_addr16[6]), \
 332         ntohs((addr).s6_addr16[7])
 333 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 334 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 335
 336 #if defined(__LITTLE_ENDIAN)
 337 #define HIPQUAD(addr) \
 338         ((unsigned char *)&addr)[3], \
 339         ((unsigned char *)&addr)[2], \
 340         ((unsigned char *)&addr)[1], \
 341         ((unsigned char *)&addr)[0]
 342 #elif defined(__BIG_ENDIAN)
 343 #define HIPQUAD NIPQUAD
 344 #else
 345 #error "Please fix asm/byteorder.h"
 346 #endif /* __LITTLE_ENDIAN */
 347
 348 /*
 349  * min()/max()/clamp() macros that also do
 350  * strict type-checking.. See the
 351  * "unnecessary" pointer comparison.
 352  */
 353 #define min(x, y) ({                            \
 354         typeof(x) _min1 = (x);                  \
 355         typeof(y) _min2 = (y);                  \
 356         (void) (&_min1 == &_min2);              \
 357         _min1 < _min2 ? _min1 : _min2; })
 358
 359 #define max(x, y) ({                            \
 360         typeof(x) _max1 = (x);                  \
 361         typeof(y) _max2 = (y);                  \
 362         (void) (&_max1 == &_max2);              \
 363         _max1 > _max2 ? _max1 : _max2; })
 364
 365 /**
 366  * clamp - return a value clamped to a given range with strict typechecking
 367  * @val: current value
 368  * @min: minimum allowable value
 369  * @max: maximum allowable value
 370  *
 371  * This macro does strict typechecking of min/max to make sure they are of the
 372  * same type as val.  See the unnecessary pointer comparisons.
 373  */
 374 #define clamp(val, min, max) ({                 \
 375         typeof(val) __val = (val);              \
 376         typeof(min) __min = (min);              \
 377         typeof(max) __max = (max);              \
 378         (void) (&__val == &__min);              \
 379         (void) (&__val == &__max);              \
 380         __val = __val < __min ? __min: __val;   \
 381         __val > __max ? __max: __val; })
 382
 383 /*
 384  * ..and if you can't take the strict
 385  * types, you can specify one yourself.
 386  *
 387  * Or not use min/max/clamp at all, of course.
 388  */
 389 #define min_t(type, x, y) ({                    \
 390         type __min1 = (x);                      \
 391         type __min2 = (y);                      \
 392         __min1 < __min2 ? __min1: __min2; })
 393
 394 #define max_t(type, x, y) ({                    \
 395         type __max1 = (x);                      \
 396         type __max2 = (y);                      \
 397         __max1 > __max2 ? __max1: __max2; })
 398
 399 /**
 400  * clamp_t - return a value clamped to a given range using a given type
 401  * @type: the type of variable to use
 402  * @val: current value
 403  * @min: minimum allowable value
 404  * @max: maximum allowable value
 405  *
 406  * This macro does no typechecking and uses temporary variables of type
 407  * 'type' to make all the comparisons.
 408  */
 409 #define clamp_t(type, val, min, max) ({         \
 410         type __val = (val);                     \
 411         type __min = (min);                     \
 412         type __max = (max);                     \
 413         __val = __val < __min ? __min: __val;   \
 414         __val > __max ? __max: __val; })
 415
 416 /**
 417  * clamp_val - return a value clamped to a given range using val's type
 418  * @val: current value
 419  * @min: minimum allowable value
 420  * @max: maximum allowable value
 421  *
 422  * This macro does no typechecking and uses temporary variables of whatever
 423  * type the input argument 'val' is.  This is useful when val is an unsigned
 424  * type and min and max are literals that will otherwise be assigned a signed
 425  * integer type.
 426  */
 427 #define clamp_val(val, min, max) ({             \
 428         typeof(val) __val = (val);              \
 429         typeof(val) __min = (min);              \
 430         typeof(val) __max = (max);              \
 431         __val = __val < __min ? __min: __val;   \
 432         __val > __max ? __max: __val; })
 433
 434 /**
 435  * container_of - cast a member of a structure out to the containing structure
 436  * @ptr:        the pointer to the member.
 437  * @type:       the type of the container struct this is embedded in.
 438  * @member:     the name of the member within the struct.
 439  *
 440  */
 441 #define container_of(ptr, type, member) ({                      \
 442         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 443         (type *)( (char *)__mptr - offsetof(type,member) );})
 444
 445 struct sysinfo;
 446 extern int do_sysinfo(struct sysinfo *info);
 447
 448 #endif /* __KERNEL__ */
 449
 450 #define SI_LOAD_SHIFT   16
 451 struct sysinfo {
 452         long uptime;                    /* Seconds since boot */
 453         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 454         unsigned long totalram;         /* Total usable main memory size */
 455         unsigned long freeram;          /* Available memory size */
 456         unsigned long sharedram;        /* Amount of shared memory */
 457         unsigned long bufferram;        /* Memory used by buffers */
 458         unsigned long totalswap;        /* Total swap space size */
 459         unsigned long freeswap;         /* swap space still available */
 460         unsigned short procs;           /* Number of current processes */
 461         unsigned short pad;             /* explicit padding for m68k */
 462         unsigned long totalhigh;        /* Total high memory size */
 463         unsigned long freehigh;         /* Available high memory size */
 464         unsigned int mem_unit;          /* Memory unit size in bytes */
 465         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 466 };
 467
 468 /* Force a compilation error if condition is true */
 469 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 470
 471 /* Force a compilation error if condition is true, but also produce a
 472    result (of value 0 and type size_t), so the expression can be used
 473    e.g. in a structure initializer (or where-ever else comma expressions
 474    aren't permitted). */
 475 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 476
 477 /* Trap pasters of __FUNCTION__ at compile-time */
 478 #define __FUNCTION__ (__func__)
 479
 480 /* This helps us to avoid #ifdef CONFIG_NUMA */
 481 #ifdef CONFIG_NUMA
 482 #define NUMA_BUILD 1
 483 #else
 484 #define NUMA_BUILD 0
 485 #endif
 486
 487 #endif