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 #define _RET_IP_                (unsigned long)__builtin_return_address(0)
  50 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
  51
  52 #ifdef CONFIG_LBD
  53 # include <asm/div64.h>
  54 # define sector_div(a, b) do_div(a, b)
  55 #else
  56 # define sector_div(n, b)( \
  57 { \
  58         int _res; \
  59         _res = (n) % (b); \
  60         (n) /= (b); \
  61         _res; \
  62 } \
  63 )
  64 #endif
  65
  66 /**
  67  * upper_32_bits - return bits 32-63 of a number
  68  * @n: the number we're accessing
  69  *
  70  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  71  * the "right shift count >= width of type" warning when that quantity is
  72  * 32-bits.
  73  */
  74 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  75
  76 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  77 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  78 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  79 #define KERN_ERR        "<3>"   /* error conditions                     */
  80 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  81 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  82 #define KERN_INFO       "<6>"   /* informational                        */
  83 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  84
  85 /*
  86  * Annotation for a "continued" line of log printout (only done after a
  87  * line that had no enclosing \n). Only to be used by core/arch code
  88  * during early bootup (a continued line is not SMP-safe otherwise).
  89  */
  90 #define KERN_CONT       ""
  91
  92 extern int console_printk[];
  93
  94 #define console_loglevel (console_printk[0])
  95 #define default_message_loglevel (console_printk[1])
  96 #define minimum_console_loglevel (console_printk[2])
  97 #define default_console_loglevel (console_printk[3])
  98
  99 struct completion;
 100 struct pt_regs;
 101 struct user;
 102
 103 /**
 104  * might_sleep - annotation for functions that can sleep
 105  *
 106  * this macro will print a stack trace if it is executed in an atomic
 107  * context (spinlock, irq-handler, ...).
 108  *
 109  * This is a useful debugging help to be able to catch problems early and not
 110  * be bitten later when the calling function happens to sleep when it is not
 111  * supposed to.
 112  */
 113 #ifdef CONFIG_PREEMPT_VOLUNTARY
 114 extern int _cond_resched(void);
 115 # define might_resched() _cond_resched()
 116 #else
 117 # define might_resched() do { } while (0)
 118 #endif
 119
 120 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 121   void __might_sleep(char *file, int line);
 122 # define might_sleep() \
 123         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 124 #else
 125 # define might_sleep() do { might_resched(); } while (0)
 126 #endif
 127
 128 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 129
 130 #define abs(x) ({                               \
 131                 int __x = (x);                  \
 132                 (__x < 0) ? -__x : __x;         \
 133         })
 134
 135 extern struct atomic_notifier_head panic_notifier_list;
 136 extern long (*panic_blink)(long time);
 137 NORET_TYPE void panic(const char * fmt, ...)
 138         __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 139 extern void oops_enter(void);
 140 extern void oops_exit(void);
 141 extern int oops_may_print(void);
 142 NORET_TYPE void do_exit(long error_code)
 143         ATTRIB_NORET;
 144 NORET_TYPE void complete_and_exit(struct completion *, long)
 145         ATTRIB_NORET;
 146 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 147 extern long simple_strtol(const char *,char **,unsigned int);
 148 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 149 extern long long simple_strtoll(const char *,char **,unsigned int);
 150 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 151 extern int strict_strtol(const char *, unsigned int, long *);
 152 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 153 extern int strict_strtoll(const char *, unsigned int, long long *);
 154 extern int sprintf(char * buf, const char * fmt, ...)
 155         __attribute__ ((format (printf, 2, 3)));
 156 extern int vsprintf(char *buf, const char *, va_list)
 157         __attribute__ ((format (printf, 2, 0)));
 158 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 159         __attribute__ ((format (printf, 3, 4)));
 160 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 161         __attribute__ ((format (printf, 3, 0)));
 162 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 163         __attribute__ ((format (printf, 3, 4)));
 164 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 165         __attribute__ ((format (printf, 3, 0)));
 166 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 167         __attribute__ ((format (printf, 2, 3)));
 168 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 169
 170 extern int sscanf(const char *, const char *, ...)
 171         __attribute__ ((format (scanf, 2, 3)));
 172 extern int vsscanf(const char *, const char *, va_list)
 173         __attribute__ ((format (scanf, 2, 0)));
 174
 175 extern int get_option(char **str, int *pint);
 176 extern char *get_options(const char *str, int nints, int *ints);
 177 extern unsigned long long memparse(char *ptr, char **retptr);
 178
 179 extern int core_kernel_text(unsigned long addr);
 180 extern int __kernel_text_address(unsigned long addr);
 181 extern int kernel_text_address(unsigned long addr);
 182 struct pid;
 183 extern struct pid *session_of_pgrp(struct pid *pgrp);
 184
 185 #ifdef CONFIG_PRINTK
 186 asmlinkage int vprintk(const char *fmt, va_list args)
 187         __attribute__ ((format (printf, 1, 0)));
 188 asmlinkage int printk(const char * fmt, ...)
 189         __attribute__ ((format (printf, 1, 2))) __cold;
 190 extern int log_buf_get_len(void);
 191 extern int log_buf_read(int idx);
 192 extern int log_buf_copy(char *dest, int idx, int len);
 193
 194 extern int printk_ratelimit_jiffies;
 195 extern int printk_ratelimit_burst;
 196 extern int printk_ratelimit(void);
 197 extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 198 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 199 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 200                                    unsigned int interval_msec);
 201 #else
 202 static inline int vprintk(const char *s, va_list args)
 203         __attribute__ ((format (printf, 1, 0)));
 204 static inline int vprintk(const char *s, va_list args) { return 0; }
 205 static inline int printk(const char *s, ...)
 206         __attribute__ ((format (printf, 1, 2)));
 207 static inline int __cold printk(const char *s, ...) { return 0; }
 208 static inline int log_buf_get_len(void) { return 0; }
 209 static inline int log_buf_read(int idx) { return 0; }
 210 static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
 211 static inline int printk_ratelimit(void) { return 0; }
 212 static inline int __printk_ratelimit(int ratelimit_jiffies, \
 213                                      int ratelimit_burst) { return 0; }
 214 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 215                                           unsigned int interval_msec)   \
 216                 { return false; }
 217 #endif
 218
 219 extern void __attribute__((format(printf, 1, 2)))
 220         early_printk(const char *fmt, ...);
 221
 222 unsigned long int_sqrt(unsigned long);
 223
 224 static inline void console_silent(void)
 225 {
 226         console_loglevel = 0;
 227 }
 228
 229 static inline void console_verbose(void)
 230 {
 231         if (console_loglevel)
 232                 console_loglevel = 15;
 233 }
 234
 235 extern void bust_spinlocks(int yes);
 236 extern void wake_up_klogd(void);
 237 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 238 extern int panic_timeout;
 239 extern int panic_on_oops;
 240 extern int panic_on_unrecovered_nmi;
 241 extern int tainted;
 242 extern const char *print_tainted(void);
 243 extern void add_taint(unsigned);
 244 extern int root_mountflags;
 245
 246 /* Values used for system_state */
 247 extern enum system_states {
 248         SYSTEM_BOOTING,
 249         SYSTEM_RUNNING,
 250         SYSTEM_HALT,
 251         SYSTEM_POWER_OFF,
 252         SYSTEM_RESTART,
 253         SYSTEM_SUSPEND_DISK,
 254 } system_state;
 255
 256 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 257 #define TAINT_FORCED_MODULE             (1<<1)
 258 #define TAINT_UNSAFE_SMP                (1<<2)
 259 #define TAINT_FORCED_RMMOD              (1<<3)
 260 #define TAINT_MACHINE_CHECK             (1<<4)
 261 #define TAINT_BAD_PAGE                  (1<<5)
 262 #define TAINT_USER                      (1<<6)
 263 #define TAINT_DIE                       (1<<7)
 264 #define TAINT_OVERRIDDEN_ACPI_TABLE     (1<<8)
 265 #define TAINT_WARN                      (1<<9)
 266
 267 extern void dump_stack(void) __cold;
 268
 269 enum {
 270         DUMP_PREFIX_NONE,
 271         DUMP_PREFIX_ADDRESS,
 272         DUMP_PREFIX_OFFSET
 273 };
 274 extern void hex_dump_to_buffer(const void *buf, size_t len,
 275                                 int rowsize, int groupsize,
 276                                 char *linebuf, size_t linebuflen, bool ascii);
 277 extern void print_hex_dump(const char *level, const char *prefix_str,
 278                                 int prefix_type, int rowsize, int groupsize,
 279                                 const void *buf, size_t len, bool ascii);
 280 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 281                         const void *buf, size_t len);
 282
 283 extern const char hex_asc[];
 284 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 285 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 286
 287 static inline char *pack_hex_byte(char *buf, u8 byte)
 288 {
 289         *buf++ = hex_asc_hi(byte);
 290         *buf++ = hex_asc_lo(byte);
 291         return buf;
 292 }
 293
 294 #define pr_emerg(fmt, arg...) \
 295         printk(KERN_EMERG fmt, ##arg)
 296 #define pr_alert(fmt, arg...) \
 297         printk(KERN_ALERT fmt, ##arg)
 298 #define pr_crit(fmt, arg...) \
 299         printk(KERN_CRIT fmt, ##arg)
 300 #define pr_err(fmt, arg...) \
 301         printk(KERN_ERR fmt, ##arg)
 302 #define pr_warning(fmt, arg...) \
 303         printk(KERN_WARNING fmt, ##arg)
 304 #define pr_notice(fmt, arg...) \
 305         printk(KERN_NOTICE fmt, ##arg)
 306 #define pr_info(fmt, arg...) \
 307         printk(KERN_INFO fmt, ##arg)
 308
 309 #ifdef DEBUG
 310 /* If you are writing a driver, please use dev_dbg instead */
 311 #define pr_debug(fmt, arg...) \
 312         printk(KERN_DEBUG fmt, ##arg)
 313 #else
 314 #define pr_debug(fmt, arg...) \
 315         ({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
 316 #endif
 317
 318 /*
 319  *      Display an IP address in readable format.
 320  */
 321
 322 #define NIPQUAD(addr) \
 323         ((unsigned char *)&addr)[0], \
 324         ((unsigned char *)&addr)[1], \
 325         ((unsigned char *)&addr)[2], \
 326         ((unsigned char *)&addr)[3]
 327 #define NIPQUAD_FMT "%u.%u.%u.%u"
 328
 329 #define NIP6(addr) \
 330         ntohs((addr).s6_addr16[0]), \
 331         ntohs((addr).s6_addr16[1]), \
 332         ntohs((addr).s6_addr16[2]), \
 333         ntohs((addr).s6_addr16[3]), \
 334         ntohs((addr).s6_addr16[4]), \
 335         ntohs((addr).s6_addr16[5]), \
 336         ntohs((addr).s6_addr16[6]), \
 337         ntohs((addr).s6_addr16[7])
 338 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 339 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 340
 341 #if defined(__LITTLE_ENDIAN)
 342 #define HIPQUAD(addr) \
 343         ((unsigned char *)&addr)[3], \
 344         ((unsigned char *)&addr)[2], \
 345         ((unsigned char *)&addr)[1], \
 346         ((unsigned char *)&addr)[0]
 347 #elif defined(__BIG_ENDIAN)
 348 #define HIPQUAD NIPQUAD
 349 #else
 350 #error "Please fix asm/byteorder.h"
 351 #endif /* __LITTLE_ENDIAN */
 352
 353 /*
 354  * min()/max()/clamp() macros that also do
 355  * strict type-checking.. See the
 356  * "unnecessary" pointer comparison.
 357  */
 358 #define min(x, y) ({                            \
 359         typeof(x) _min1 = (x);                  \
 360         typeof(y) _min2 = (y);                  \
 361         (void) (&_min1 == &_min2);              \
 362         _min1 < _min2 ? _min1 : _min2; })
 363
 364 #define max(x, y) ({                            \
 365         typeof(x) _max1 = (x);                  \
 366         typeof(y) _max2 = (y);                  \
 367         (void) (&_max1 == &_max2);              \
 368         _max1 > _max2 ? _max1 : _max2; })
 369
 370 /**
 371  * clamp - return a value clamped to a given range with strict typechecking
 372  * @val: current value
 373  * @min: minimum allowable value
 374  * @max: maximum allowable value
 375  *
 376  * This macro does strict typechecking of min/max to make sure they are of the
 377  * same type as val.  See the unnecessary pointer comparisons.
 378  */
 379 #define clamp(val, min, max) ({                 \
 380         typeof(val) __val = (val);              \
 381         typeof(min) __min = (min);              \
 382         typeof(max) __max = (max);              \
 383         (void) (&__val == &__min);              \
 384         (void) (&__val == &__max);              \
 385         __val = __val < __min ? __min: __val;   \
 386         __val > __max ? __max: __val; })
 387
 388 /*
 389  * ..and if you can't take the strict
 390  * types, you can specify one yourself.
 391  *
 392  * Or not use min/max/clamp at all, of course.
 393  */
 394 #define min_t(type, x, y) ({                    \
 395         type __min1 = (x);                      \
 396         type __min2 = (y);                      \
 397         __min1 < __min2 ? __min1: __min2; })
 398
 399 #define max_t(type, x, y) ({                    \
 400         type __max1 = (x);                      \
 401         type __max2 = (y);                      \
 402         __max1 > __max2 ? __max1: __max2; })
 403
 404 /**
 405  * clamp_t - return a value clamped to a given range using a given type
 406  * @type: the type of variable to use
 407  * @val: current value
 408  * @min: minimum allowable value
 409  * @max: maximum allowable value
 410  *
 411  * This macro does no typechecking and uses temporary variables of type
 412  * 'type' to make all the comparisons.
 413  */
 414 #define clamp_t(type, val, min, max) ({         \
 415         type __val = (val);                     \
 416         type __min = (min);                     \
 417         type __max = (max);                     \
 418         __val = __val < __min ? __min: __val;   \
 419         __val > __max ? __max: __val; })
 420
 421 /**
 422  * clamp_val - return a value clamped to a given range using val's type
 423  * @val: current value
 424  * @min: minimum allowable value
 425  * @max: maximum allowable value
 426  *
 427  * This macro does no typechecking and uses temporary variables of whatever
 428  * type the input argument 'val' is.  This is useful when val is an unsigned
 429  * type and min and max are literals that will otherwise be assigned a signed
 430  * integer type.
 431  */
 432 #define clamp_val(val, min, max) ({             \
 433         typeof(val) __val = (val);              \
 434         typeof(val) __min = (min);              \
 435         typeof(val) __max = (max);              \
 436         __val = __val < __min ? __min: __val;   \
 437         __val > __max ? __max: __val; })
 438
 439 /**
 440  * container_of - cast a member of a structure out to the containing structure
 441  * @ptr:        the pointer to the member.
 442  * @type:       the type of the container struct this is embedded in.
 443  * @member:     the name of the member within the struct.
 444  *
 445  */
 446 #define container_of(ptr, type, member) ({                      \
 447         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 448         (type *)( (char *)__mptr - offsetof(type,member) );})
 449
 450 /*
 451  * Check at compile time that something is of a particular type.
 452  * Always evaluates to 1 so you may use it easily in comparisons.
 453  */
 454 #define typecheck(type,x) \
 455 ({      type __dummy; \
 456         typeof(x) __dummy2; \
 457         (void)(&__dummy == &__dummy2); \
 458         1; \
 459 })
 460
 461 /*
 462  * Check at compile time that 'function' is a certain type, or is a pointer
 463  * to that type (needs to use typedef for the function type.)
 464  */
 465 #define typecheck_fn(type,function) \
 466 ({      typeof(type) __tmp = function; \
 467         (void)__tmp; \
 468 })
 469
 470 struct sysinfo;
 471 extern int do_sysinfo(struct sysinfo *info);
 472
 473 #endif /* __KERNEL__ */
 474
 475 #define SI_LOAD_SHIFT   16
 476 struct sysinfo {
 477         long uptime;                    /* Seconds since boot */
 478         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 479         unsigned long totalram;         /* Total usable main memory size */
 480         unsigned long freeram;          /* Available memory size */
 481         unsigned long sharedram;        /* Amount of shared memory */
 482         unsigned long bufferram;        /* Memory used by buffers */
 483         unsigned long totalswap;        /* Total swap space size */
 484         unsigned long freeswap;         /* swap space still available */
 485         unsigned short procs;           /* Number of current processes */
 486         unsigned short pad;             /* explicit padding for m68k */
 487         unsigned long totalhigh;        /* Total high memory size */
 488         unsigned long freehigh;         /* Available high memory size */
 489         unsigned int mem_unit;          /* Memory unit size in bytes */
 490         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 491 };
 492
 493 /* Force a compilation error if condition is true */
 494 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 495
 496 /* Force a compilation error if condition is true, but also produce a
 497    result (of value 0 and type size_t), so the expression can be used
 498    e.g. in a structure initializer (or where-ever else comma expressions
 499    aren't permitted). */
 500 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 501
 502 /* Trap pasters of __FUNCTION__ at compile-time */
 503 #define __FUNCTION__ (__func__)
 504
 505 /* This helps us to avoid #ifdef CONFIG_NUMA */
 506 #ifdef CONFIG_NUMA
 507 #define NUMA_BUILD 1
 508 #else
 509 #define NUMA_BUILD 0
 510 #endif
 511
 512 #endif