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 USHORT_MAX      ((u16)(~0U))
  24 #define SHORT_MAX       ((s16)(USHORT_MAX>>1))
  25 #define SHORT_MIN       (-SHORT_MAX - 1)
  26 #define INT_MAX         ((int)(~0U>>1))
  27 #define INT_MIN         (-INT_MAX - 1)
  28 #define UINT_MAX        (~0U)
  29 #define LONG_MAX        ((long)(~0UL>>1))
  30 #define LONG_MIN        (-LONG_MAX - 1)
  31 #define ULONG_MAX       (~0UL)
  32 #define LLONG_MAX       ((long long)(~0ULL>>1))
  33 #define LLONG_MIN       (-LLONG_MAX - 1)
  34 #define ULLONG_MAX      (~0ULL)
  35
  36 #define STACK_MAGIC     0xdeadbeef
  37
  38 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  39 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  40 #define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  41 #define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  42
  43 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  44
  45 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  46 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  47 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  48
  49 #ifdef CONFIG_LBD
  50 # include <asm/div64.h>
  51 # define sector_div(a, b) do_div(a, b)
  52 #else
  53 # define sector_div(n, b)( \
  54 { \
  55         int _res; \
  56         _res = (n) % (b); \
  57         (n) /= (b); \
  58         _res; \
  59 } \
  60 )
  61 #endif
  62
  63 /**
  64  * upper_32_bits - return bits 32-63 of a number
  65  * @n: the number we're accessing
  66  *
  67  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  68  * the "right shift count >= width of type" warning when that quantity is
  69  * 32-bits.
  70  */
  71 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  72
  73 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  74 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  75 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  76 #define KERN_ERR        "<3>"   /* error conditions                     */
  77 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  78 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  79 #define KERN_INFO       "<6>"   /* informational                        */
  80 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  81
  82 /*
  83  * Annotation for a "continued" line of log printout (only done after a
  84  * line that had no enclosing \n). Only to be used by core/arch code
  85  * during early bootup (a continued line is not SMP-safe otherwise).
  86  */
  87 #define KERN_CONT       ""
  88
  89 extern int console_printk[];
  90
  91 #define console_loglevel (console_printk[0])
  92 #define default_message_loglevel (console_printk[1])
  93 #define minimum_console_loglevel (console_printk[2])
  94 #define default_console_loglevel (console_printk[3])
  95
  96 struct completion;
  97 struct pt_regs;
  98 struct user;
  99
 100 /**
 101  * might_sleep - annotation for functions that can sleep
 102  *
 103  * this macro will print a stack trace if it is executed in an atomic
 104  * context (spinlock, irq-handler, ...).
 105  *
 106  * This is a useful debugging help to be able to catch problems early and not
 107  * be bitten later when the calling function happens to sleep when it is not
 108  * supposed to.
 109  */
 110 #ifdef CONFIG_PREEMPT_VOLUNTARY
 111 extern int _cond_resched(void);
 112 # define might_resched() _cond_resched()
 113 #else
 114 # define might_resched() do { } while (0)
 115 #endif
 116
 117 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 118   void __might_sleep(char *file, int line);
 119 # define might_sleep() \
 120         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 121 #else
 122 # define might_sleep() do { might_resched(); } while (0)
 123 #endif
 124
 125 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 126
 127 #define abs(x) ({                               \
 128                 int __x = (x);                  \
 129                 (__x < 0) ? -__x : __x;         \
 130         })
 131
 132 extern struct atomic_notifier_head panic_notifier_list;
 133 extern long (*panic_blink)(long time);
 134 NORET_TYPE void panic(const char * fmt, ...)
 135         __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 136 extern void oops_enter(void);
 137 extern void oops_exit(void);
 138 extern int oops_may_print(void);
 139 NORET_TYPE void do_exit(long error_code)
 140         ATTRIB_NORET;
 141 NORET_TYPE void complete_and_exit(struct completion *, long)
 142         ATTRIB_NORET;
 143 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 144 extern long simple_strtol(const char *,char **,unsigned int);
 145 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 146 extern long long simple_strtoll(const char *,char **,unsigned int);
 147 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 148 extern int strict_strtol(const char *, unsigned int, long *);
 149 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 150 extern int strict_strtoll(const char *, unsigned int, long long *);
 151 extern int sprintf(char * buf, const char * fmt, ...)
 152         __attribute__ ((format (printf, 2, 3)));
 153 extern int vsprintf(char *buf, const char *, va_list)
 154         __attribute__ ((format (printf, 2, 0)));
 155 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 156         __attribute__ ((format (printf, 3, 4)));
 157 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 158         __attribute__ ((format (printf, 3, 0)));
 159 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 160         __attribute__ ((format (printf, 3, 4)));
 161 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 162         __attribute__ ((format (printf, 3, 0)));
 163 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 164         __attribute__ ((format (printf, 2, 3)));
 165 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 166
 167 extern int sscanf(const char *, const char *, ...)
 168         __attribute__ ((format (scanf, 2, 3)));
 169 extern int vsscanf(const char *, const char *, va_list)
 170         __attribute__ ((format (scanf, 2, 0)));
 171
 172 extern int get_option(char **str, int *pint);
 173 extern char *get_options(const char *str, int nints, int *ints);
 174 extern unsigned long long memparse(char *ptr, char **retptr);
 175
 176 extern int core_kernel_text(unsigned long addr);
 177 extern int __kernel_text_address(unsigned long addr);
 178 extern int kernel_text_address(unsigned long addr);
 179 struct pid;
 180 extern struct pid *session_of_pgrp(struct pid *pgrp);
 181
 182 #ifdef CONFIG_PRINTK
 183 asmlinkage int vprintk(const char *fmt, va_list args)
 184         __attribute__ ((format (printf, 1, 0)));
 185 asmlinkage int printk(const char * fmt, ...)
 186         __attribute__ ((format (printf, 1, 2))) __cold;
 187 extern int log_buf_get_len(void);
 188 extern int log_buf_read(int idx);
 189 extern int log_buf_copy(char *dest, int idx, int len);
 190
 191 extern int printk_ratelimit_jiffies;
 192 extern int printk_ratelimit_burst;
 193 extern int printk_ratelimit(void);
 194 extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 195 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 196 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 197                                    unsigned int interval_msec);
 198 #else
 199 static inline int vprintk(const char *s, va_list args)
 200         __attribute__ ((format (printf, 1, 0)));
 201 static inline int vprintk(const char *s, va_list args) { return 0; }
 202 static inline int printk(const char *s, ...)
 203         __attribute__ ((format (printf, 1, 2)));
 204 static inline int __cold printk(const char *s, ...) { return 0; }
 205 static inline int log_buf_get_len(void) { return 0; }
 206 static inline int log_buf_read(int idx) { return 0; }
 207 static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
 208 static inline int printk_ratelimit(void) { return 0; }
 209 static inline int __printk_ratelimit(int ratelimit_jiffies, \
 210                                      int ratelimit_burst) { return 0; }
 211 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 212                                           unsigned int interval_msec)   \
 213                 { return false; }
 214 #endif
 215
 216 extern void __attribute__((format(printf, 1, 2)))
 217         early_printk(const char *fmt, ...);
 218
 219 unsigned long int_sqrt(unsigned long);
 220
 221 static inline void console_silent(void)
 222 {
 223         console_loglevel = 0;
 224 }
 225
 226 static inline void console_verbose(void)
 227 {
 228         if (console_loglevel)
 229                 console_loglevel = 15;
 230 }
 231
 232 extern void bust_spinlocks(int yes);
 233 extern void wake_up_klogd(void);
 234 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 235 extern int panic_timeout;
 236 extern int panic_on_oops;
 237 extern int panic_on_unrecovered_nmi;
 238 extern int tainted;
 239 extern const char *print_tainted(void);
 240 extern void add_taint(unsigned);
 241 extern int root_mountflags;
 242
 243 /* Values used for system_state */
 244 extern enum system_states {
 245         SYSTEM_BOOTING,
 246         SYSTEM_RUNNING,
 247         SYSTEM_HALT,
 248         SYSTEM_POWER_OFF,
 249         SYSTEM_RESTART,
 250         SYSTEM_SUSPEND_DISK,
 251 } system_state;
 252
 253 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 254 #define TAINT_FORCED_MODULE             (1<<1)
 255 #define TAINT_UNSAFE_SMP                (1<<2)
 256 #define TAINT_FORCED_RMMOD              (1<<3)
 257 #define TAINT_MACHINE_CHECK             (1<<4)
 258 #define TAINT_BAD_PAGE                  (1<<5)
 259 #define TAINT_USER                      (1<<6)
 260 #define TAINT_DIE                       (1<<7)
 261 #define TAINT_OVERRIDDEN_ACPI_TABLE     (1<<8)
 262 #define TAINT_WARN                      (1<<9)
 263
 264 extern void dump_stack(void) __cold;
 265
 266 enum {
 267         DUMP_PREFIX_NONE,
 268         DUMP_PREFIX_ADDRESS,
 269         DUMP_PREFIX_OFFSET
 270 };
 271 extern void hex_dump_to_buffer(const void *buf, size_t len,
 272                                 int rowsize, int groupsize,
 273                                 char *linebuf, size_t linebuflen, bool ascii);
 274 extern void print_hex_dump(const char *level, const char *prefix_str,
 275                                 int prefix_type, int rowsize, int groupsize,
 276                                 const void *buf, size_t len, bool ascii);
 277 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 278                         const void *buf, size_t len);
 279
 280 extern const char hex_asc[];
 281 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 282 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 283
 284 static inline char *pack_hex_byte(char *buf, u8 byte)
 285 {
 286         *buf++ = hex_asc_hi(byte);
 287         *buf++ = hex_asc_lo(byte);
 288         return buf;
 289 }
 290
 291 #define pr_emerg(fmt, arg...) \
 292         printk(KERN_EMERG fmt, ##arg)
 293 #define pr_alert(fmt, arg...) \
 294         printk(KERN_ALERT fmt, ##arg)
 295 #define pr_crit(fmt, arg...) \
 296         printk(KERN_CRIT fmt, ##arg)
 297 #define pr_err(fmt, arg...) \
 298         printk(KERN_ERR fmt, ##arg)
 299 #define pr_warning(fmt, arg...) \
 300         printk(KERN_WARNING fmt, ##arg)
 301 #define pr_notice(fmt, arg...) \
 302         printk(KERN_NOTICE fmt, ##arg)
 303 #define pr_info(fmt, arg...) \
 304         printk(KERN_INFO fmt, ##arg)
 305
 306 #ifdef DEBUG
 307 /* If you are writing a driver, please use dev_dbg instead */
 308 #define pr_debug(fmt, arg...) \
 309         printk(KERN_DEBUG fmt, ##arg)
 310 #else
 311 #define pr_debug(fmt, arg...) \
 312         ({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
 313 #endif
 314
 315 /*
 316  *      Display an IP address in readable format.
 317  */
 318
 319 #define NIPQUAD(addr) \
 320         ((unsigned char *)&addr)[0], \
 321         ((unsigned char *)&addr)[1], \
 322         ((unsigned char *)&addr)[2], \
 323         ((unsigned char *)&addr)[3]
 324 #define NIPQUAD_FMT "%u.%u.%u.%u"
 325
 326 #define NIP6(addr) \
 327         ntohs((addr).s6_addr16[0]), \
 328         ntohs((addr).s6_addr16[1]), \
 329         ntohs((addr).s6_addr16[2]), \
 330         ntohs((addr).s6_addr16[3]), \
 331         ntohs((addr).s6_addr16[4]), \
 332         ntohs((addr).s6_addr16[5]), \
 333         ntohs((addr).s6_addr16[6]), \
 334         ntohs((addr).s6_addr16[7])
 335 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 336 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 337
 338 #if defined(__LITTLE_ENDIAN)
 339 #define HIPQUAD(addr) \
 340         ((unsigned char *)&addr)[3], \
 341         ((unsigned char *)&addr)[2], \
 342         ((unsigned char *)&addr)[1], \
 343         ((unsigned char *)&addr)[0]
 344 #elif defined(__BIG_ENDIAN)
 345 #define HIPQUAD NIPQUAD
 346 #else
 347 #error "Please fix asm/byteorder.h"
 348 #endif /* __LITTLE_ENDIAN */
 349
 350 /*
 351  * min()/max()/clamp() macros that also do
 352  * strict type-checking.. See the
 353  * "unnecessary" pointer comparison.
 354  */
 355 #define min(x, y) ({                            \
 356         typeof(x) _min1 = (x);                  \
 357         typeof(y) _min2 = (y);                  \
 358         (void) (&_min1 == &_min2);              \
 359         _min1 < _min2 ? _min1 : _min2; })
 360
 361 #define max(x, y) ({                            \
 362         typeof(x) _max1 = (x);                  \
 363         typeof(y) _max2 = (y);                  \
 364         (void) (&_max1 == &_max2);              \
 365         _max1 > _max2 ? _max1 : _max2; })
 366
 367 /**
 368  * clamp - return a value clamped to a given range with strict typechecking
 369  * @val: current value
 370  * @min: minimum allowable value
 371  * @max: maximum allowable value
 372  *
 373  * This macro does strict typechecking of min/max to make sure they are of the
 374  * same type as val.  See the unnecessary pointer comparisons.
 375  */
 376 #define clamp(val, min, max) ({                 \
 377         typeof(val) __val = (val);              \
 378         typeof(min) __min = (min);              \
 379         typeof(max) __max = (max);              \
 380         (void) (&__val == &__min);              \
 381         (void) (&__val == &__max);              \
 382         __val = __val < __min ? __min: __val;   \
 383         __val > __max ? __max: __val; })
 384
 385 /*
 386  * ..and if you can't take the strict
 387  * types, you can specify one yourself.
 388  *
 389  * Or not use min/max/clamp at all, of course.
 390  */
 391 #define min_t(type, x, y) ({                    \
 392         type __min1 = (x);                      \
 393         type __min2 = (y);                      \
 394         __min1 < __min2 ? __min1: __min2; })
 395
 396 #define max_t(type, x, y) ({                    \
 397         type __max1 = (x);                      \
 398         type __max2 = (y);                      \
 399         __max1 > __max2 ? __max1: __max2; })
 400
 401 /**
 402  * clamp_t - return a value clamped to a given range using a given type
 403  * @type: the type of variable to use
 404  * @val: current value
 405  * @min: minimum allowable value
 406  * @max: maximum allowable value
 407  *
 408  * This macro does no typechecking and uses temporary variables of type
 409  * 'type' to make all the comparisons.
 410  */
 411 #define clamp_t(type, val, min, max) ({         \
 412         type __val = (val);                     \
 413         type __min = (min);                     \
 414         type __max = (max);                     \
 415         __val = __val < __min ? __min: __val;   \
 416         __val > __max ? __max: __val; })
 417
 418 /**
 419  * clamp_val - return a value clamped to a given range using val's type
 420  * @val: current value
 421  * @min: minimum allowable value
 422  * @max: maximum allowable value
 423  *
 424  * This macro does no typechecking and uses temporary variables of whatever
 425  * type the input argument 'val' is.  This is useful when val is an unsigned
 426  * type and min and max are literals that will otherwise be assigned a signed
 427  * integer type.
 428  */
 429 #define clamp_val(val, min, max) ({             \
 430         typeof(val) __val = (val);              \
 431         typeof(val) __min = (min);              \
 432         typeof(val) __max = (max);              \
 433         __val = __val < __min ? __min: __val;   \
 434         __val > __max ? __max: __val; })
 435
 436 /**
 437  * container_of - cast a member of a structure out to the containing structure
 438  * @ptr:        the pointer to the member.
 439  * @type:       the type of the container struct this is embedded in.
 440  * @member:     the name of the member within the struct.
 441  *
 442  */
 443 #define container_of(ptr, type, member) ({                      \
 444         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 445         (type *)( (char *)__mptr - offsetof(type,member) );})
 446
 447 /*
 448  * Check at compile time that something is of a particular type.
 449  * Always evaluates to 1 so you may use it easily in comparisons.
 450  */
 451 #define typecheck(type,x) \
 452 ({      type __dummy; \
 453         typeof(x) __dummy2; \
 454         (void)(&__dummy == &__dummy2); \
 455         1; \
 456 })
 457
 458 /*
 459  * Check at compile time that 'function' is a certain type, or is a pointer
 460  * to that type (needs to use typedef for the function type.)
 461  */
 462 #define typecheck_fn(type,function) \
 463 ({      typeof(type) __tmp = function; \
 464         (void)__tmp; \
 465 })
 466
 467 struct sysinfo;
 468 extern int do_sysinfo(struct sysinfo *info);
 469
 470 #endif /* __KERNEL__ */
 471
 472 #define SI_LOAD_SHIFT   16
 473 struct sysinfo {
 474         long uptime;                    /* Seconds since boot */
 475         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 476         unsigned long totalram;         /* Total usable main memory size */
 477         unsigned long freeram;          /* Available memory size */
 478         unsigned long sharedram;        /* Amount of shared memory */
 479         unsigned long bufferram;        /* Memory used by buffers */
 480         unsigned long totalswap;        /* Total swap space size */
 481         unsigned long freeswap;         /* swap space still available */
 482         unsigned short procs;           /* Number of current processes */
 483         unsigned short pad;             /* explicit padding for m68k */
 484         unsigned long totalhigh;        /* Total high memory size */
 485         unsigned long freehigh;         /* Available high memory size */
 486         unsigned int mem_unit;          /* Memory unit size in bytes */
 487         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 488 };
 489
 490 /* Force a compilation error if condition is true */
 491 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 492
 493 /* Force a compilation error if condition is true, but also produce a
 494    result (of value 0 and type size_t), so the expression can be used
 495    e.g. in a structure initializer (or where-ever else comma expressions
 496    aren't permitted). */
 497 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 498
 499 /* Trap pasters of __FUNCTION__ at compile-time */
 500 #define __FUNCTION__ (__func__)
 501
 502 /* This helps us to avoid #ifdef CONFIG_NUMA */
 503 #ifdef CONFIG_NUMA
 504 #define NUMA_BUILD 1
 505 #else
 506 #define NUMA_BUILD 0
 507 #endif
 508
 509 #endif