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