linux/include/linux/kernel.h
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   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
  20extern const char linux_banner[];
  21extern 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#define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  38#define IS_ALIGNED(x,a)         (((x) % ((typeof(x))(a))) == 0)
  39
  40#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  41
  42#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  43#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  44#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  45
  46#ifdef CONFIG_LBD
  47# include <asm/div64.h>
  48# define sector_div(a, b) do_div(a, b)
  49#else
  50# define sector_div(n, b)( \
  51{ \
  52        int _res; \
  53        _res = (n) % (b); \
  54        (n) /= (b); \
  55        _res; \
  56} \
  57)
  58#endif
  59
  60/**
  61 * upper_32_bits - return bits 32-63 of a number
  62 * @n: the number we're accessing
  63 *
  64 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  65 * the "right shift count >= width of type" warning when that quantity is
  66 * 32-bits.
  67 */
  68#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  69
  70#define KERN_EMERG      "<0>"   /* system is unusable                   */
  71#define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  72#define KERN_CRIT       "<2>"   /* critical conditions                  */
  73#define KERN_ERR        "<3>"   /* error conditions                     */
  74#define KERN_WARNING    "<4>"   /* warning conditions                   */
  75#define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  76#define KERN_INFO       "<6>"   /* informational                        */
  77#define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  78
  79/*
  80 * Annotation for a "continued" line of log printout (only done after a
  81 * line that had no enclosing \n). Only to be used by core/arch code
  82 * during early bootup (a continued line is not SMP-safe otherwise).
  83 */
  84#define KERN_CONT       ""
  85
  86extern int console_printk[];
  87
  88#define console_loglevel (console_printk[0])
  89#define default_message_loglevel (console_printk[1])
  90#define minimum_console_loglevel (console_printk[2])
  91#define default_console_loglevel (console_printk[3])
  92
  93struct completion;
  94struct pt_regs;
  95struct user;
  96
  97/**
  98 * might_sleep - annotation for functions that can sleep
  99 *
 100 * this macro will print a stack trace if it is executed in an atomic
 101 * context (spinlock, irq-handler, ...).
 102 *
 103 * This is a useful debugging help to be able to catch problems early and not
 104 * be bitten later when the calling function happens to sleep when it is not
 105 * supposed to.
 106 */
 107#ifdef CONFIG_PREEMPT_VOLUNTARY
 108extern int cond_resched(void);
 109# define might_resched() cond_resched()
 110#else
 111# define might_resched() do { } while (0)
 112#endif
 113
 114#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 115  void __might_sleep(char *file, int line);
 116# define might_sleep() \
 117        do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 118#else
 119# define might_sleep() do { might_resched(); } while (0)
 120#endif
 121
 122#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 123
 124#define abs(x) ({                               \
 125                int __x = (x);                  \
 126                (__x < 0) ? -__x : __x;         \
 127        })
 128
 129extern struct atomic_notifier_head panic_notifier_list;
 130extern long (*panic_blink)(long time);
 131NORET_TYPE void panic(const char * fmt, ...)
 132        __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 133extern void oops_enter(void);
 134extern void oops_exit(void);
 135extern int oops_may_print(void);
 136fastcall NORET_TYPE void do_exit(long error_code)
 137        ATTRIB_NORET;
 138NORET_TYPE void complete_and_exit(struct completion *, long)
 139        ATTRIB_NORET;
 140extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 141extern long simple_strtol(const char *,char **,unsigned int);
 142extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 143extern long long simple_strtoll(const char *,char **,unsigned int);
 144extern int sprintf(char * buf, const char * fmt, ...)
 145        __attribute__ ((format (printf, 2, 3)));
 146extern int vsprintf(char *buf, const char *, va_list)
 147        __attribute__ ((format (printf, 2, 0)));
 148extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 149        __attribute__ ((format (printf, 3, 4)));
 150extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 151        __attribute__ ((format (printf, 3, 0)));
 152extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 153        __attribute__ ((format (printf, 3, 4)));
 154extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 155        __attribute__ ((format (printf, 3, 0)));
 156extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 157        __attribute__ ((format (printf, 2, 3)));
 158extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 159
 160extern int sscanf(const char *, const char *, ...)
 161        __attribute__ ((format (scanf, 2, 3)));
 162extern int vsscanf(const char *, const char *, va_list)
 163        __attribute__ ((format (scanf, 2, 0)));
 164
 165extern int get_option(char **str, int *pint);
 166extern char *get_options(const char *str, int nints, int *ints);
 167extern unsigned long long memparse(char *ptr, char **retptr);
 168
 169extern int core_kernel_text(unsigned long addr);
 170extern int __kernel_text_address(unsigned long addr);
 171extern int kernel_text_address(unsigned long addr);
 172struct pid;
 173extern struct pid *session_of_pgrp(struct pid *pgrp);
 174
 175extern void dump_thread(struct pt_regs *regs, struct user *dump);
 176
 177#ifdef CONFIG_PRINTK
 178asmlinkage int vprintk(const char *fmt, va_list args)
 179        __attribute__ ((format (printf, 1, 0)));
 180asmlinkage int printk(const char * fmt, ...)
 181        __attribute__ ((format (printf, 1, 2))) __cold;
 182extern int log_buf_get_len(void);
 183extern int log_buf_read(int idx);
 184extern int log_buf_copy(char *dest, int idx, int len);
 185#else
 186static inline int vprintk(const char *s, va_list args)
 187        __attribute__ ((format (printf, 1, 0)));
 188static inline int vprintk(const char *s, va_list args) { return 0; }
 189static inline int printk(const char *s, ...)
 190        __attribute__ ((format (printf, 1, 2)));
 191static inline int __cold printk(const char *s, ...) { return 0; }
 192static inline int log_buf_get_len(void) { return 0; }
 193static inline int log_buf_read(int idx) { return 0; }
 194static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
 195#endif
 196
 197unsigned long int_sqrt(unsigned long);
 198
 199extern int printk_ratelimit(void);
 200extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 201extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 202                                unsigned int interval_msec);
 203
 204static inline void console_silent(void)
 205{
 206        console_loglevel = 0;
 207}
 208
 209static inline void console_verbose(void)
 210{
 211        if (console_loglevel)
 212                console_loglevel = 15;
 213}
 214
 215extern void bust_spinlocks(int yes);
 216extern void wake_up_klogd(void);
 217extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 218extern int panic_timeout;
 219extern int panic_on_oops;
 220extern int panic_on_unrecovered_nmi;
 221extern int tainted;
 222extern const char *print_tainted(void);
 223extern void add_taint(unsigned);
 224
 225/* Values used for system_state */
 226extern enum system_states {
 227        SYSTEM_BOOTING,
 228        SYSTEM_RUNNING,
 229        SYSTEM_HALT,
 230        SYSTEM_POWER_OFF,
 231        SYSTEM_RESTART,
 232        SYSTEM_SUSPEND_DISK,
 233} system_state;
 234
 235#define TAINT_PROPRIETARY_MODULE        (1<<0)
 236#define TAINT_FORCED_MODULE             (1<<1)
 237#define TAINT_UNSAFE_SMP                (1<<2)
 238#define TAINT_FORCED_RMMOD              (1<<3)
 239#define TAINT_MACHINE_CHECK             (1<<4)
 240#define TAINT_BAD_PAGE                  (1<<5)
 241#define TAINT_USER                      (1<<6)
 242#define TAINT_DIE                       (1<<7)
 243
 244extern void dump_stack(void) __cold;
 245
 246enum {
 247        DUMP_PREFIX_NONE,
 248        DUMP_PREFIX_ADDRESS,
 249        DUMP_PREFIX_OFFSET
 250};
 251extern void hex_dump_to_buffer(const void *buf, size_t len,
 252                                int rowsize, int groupsize,
 253                                char *linebuf, size_t linebuflen, bool ascii);
 254extern void print_hex_dump(const char *level, const char *prefix_str,
 255                                int prefix_type, int rowsize, int groupsize,
 256                                const void *buf, size_t len, bool ascii);
 257extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 258                        const void *buf, size_t len);
 259#define hex_asc(x)      "0123456789abcdef"[x]
 260
 261#define pr_emerg(fmt, arg...) \
 262        printk(KERN_EMERG fmt, ##arg)
 263#define pr_alert(fmt, arg...) \
 264        printk(KERN_ALERT fmt, ##arg)
 265#define pr_crit(fmt, arg...) \
 266        printk(KERN_CRIT fmt, ##arg)
 267#define pr_err(fmt, arg...) \
 268        printk(KERN_ERR fmt, ##arg)
 269#define pr_warning(fmt, arg...) \
 270        printk(KERN_WARNING fmt, ##arg)
 271#define pr_notice(fmt, arg...) \
 272        printk(KERN_NOTICE fmt, ##arg)
 273#define pr_info(fmt, arg...) \
 274        printk(KERN_INFO fmt, ##arg)
 275
 276#ifdef DEBUG
 277/* If you are writing a driver, please use dev_dbg instead */
 278#define pr_debug(fmt, arg...) \
 279        printk(KERN_DEBUG fmt, ##arg)
 280#else
 281static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
 282{
 283        return 0;
 284}
 285#endif
 286
 287/*
 288 *      Display an IP address in readable format.
 289 */
 290
 291#define NIPQUAD(addr) \
 292        ((unsigned char *)&addr)[0], \
 293        ((unsigned char *)&addr)[1], \
 294        ((unsigned char *)&addr)[2], \
 295        ((unsigned char *)&addr)[3]
 296#define NIPQUAD_FMT "%u.%u.%u.%u"
 297
 298#define NIP6(addr) \
 299        ntohs((addr).s6_addr16[0]), \
 300        ntohs((addr).s6_addr16[1]), \
 301        ntohs((addr).s6_addr16[2]), \
 302        ntohs((addr).s6_addr16[3]), \
 303        ntohs((addr).s6_addr16[4]), \
 304        ntohs((addr).s6_addr16[5]), \
 305        ntohs((addr).s6_addr16[6]), \
 306        ntohs((addr).s6_addr16[7])
 307#define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 308#define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 309
 310#if defined(__LITTLE_ENDIAN)
 311#define HIPQUAD(addr) \
 312        ((unsigned char *)&addr)[3], \
 313        ((unsigned char *)&addr)[2], \
 314        ((unsigned char *)&addr)[1], \
 315        ((unsigned char *)&addr)[0]
 316#elif defined(__BIG_ENDIAN)
 317#define HIPQUAD NIPQUAD
 318#else
 319#error "Please fix asm/byteorder.h"
 320#endif /* __LITTLE_ENDIAN */
 321
 322/*
 323 * min()/max() macros that also do
 324 * strict type-checking.. See the
 325 * "unnecessary" pointer comparison.
 326 */
 327#define min(x,y) ({ \
 328        typeof(x) _x = (x);     \
 329        typeof(y) _y = (y);     \
 330        (void) (&_x == &_y);            \
 331        _x < _y ? _x : _y; })
 332
 333#define max(x,y) ({ \
 334        typeof(x) _x = (x);     \
 335        typeof(y) _y = (y);     \
 336        (void) (&_x == &_y);            \
 337        _x > _y ? _x : _y; })
 338
 339/*
 340 * ..and if you can't take the strict
 341 * types, you can specify one yourself.
 342 *
 343 * Or not use min/max at all, of course.
 344 */
 345#define min_t(type,x,y) \
 346        ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 347#define max_t(type,x,y) \
 348        ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 349
 350
 351/**
 352 * container_of - cast a member of a structure out to the containing structure
 353 * @ptr:        the pointer to the member.
 354 * @type:       the type of the container struct this is embedded in.
 355 * @member:     the name of the member within the struct.
 356 *
 357 */
 358#define container_of(ptr, type, member) ({                      \
 359        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 360        (type *)( (char *)__mptr - offsetof(type,member) );})
 361
 362/*
 363 * Check at compile time that something is of a particular type.
 364 * Always evaluates to 1 so you may use it easily in comparisons.
 365 */
 366#define typecheck(type,x) \
 367({      type __dummy; \
 368        typeof(x) __dummy2; \
 369        (void)(&__dummy == &__dummy2); \
 370        1; \
 371})
 372
 373/*
 374 * Check at compile time that 'function' is a certain type, or is a pointer
 375 * to that type (needs to use typedef for the function type.)
 376 */
 377#define typecheck_fn(type,function) \
 378({      typeof(type) __tmp = function; \
 379        (void)__tmp; \
 380})
 381
 382struct sysinfo;
 383extern int do_sysinfo(struct sysinfo *info);
 384
 385#endif /* __KERNEL__ */
 386
 387#define SI_LOAD_SHIFT   16
 388struct sysinfo {
 389        long uptime;                    /* Seconds since boot */
 390        unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 391        unsigned long totalram;         /* Total usable main memory size */
 392        unsigned long freeram;          /* Available memory size */
 393        unsigned long sharedram;        /* Amount of shared memory */
 394        unsigned long bufferram;        /* Memory used by buffers */
 395        unsigned long totalswap;        /* Total swap space size */
 396        unsigned long freeswap;         /* swap space still available */
 397        unsigned short procs;           /* Number of current processes */
 398        unsigned short pad;             /* explicit padding for m68k */
 399        unsigned long totalhigh;        /* Total high memory size */
 400        unsigned long freehigh;         /* Available high memory size */
 401        unsigned int mem_unit;          /* Memory unit size in bytes */
 402        char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 403};
 404
 405/* Force a compilation error if condition is true */
 406#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 407
 408/* Force a compilation error if condition is true, but also produce a
 409   result (of value 0 and type size_t), so the expression can be used
 410   e.g. in a structure initializer (or where-ever else comma expressions
 411   aren't permitted). */
 412#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 413
 414/* Trap pasters of __FUNCTION__ at compile-time */
 415#define __FUNCTION__ (__func__)
 416
 417/* This helps us to avoid #ifdef CONFIG_NUMA */
 418#ifdef CONFIG_NUMA
 419#define NUMA_BUILD 1
 420#else
 421#define NUMA_BUILD 0
 422#endif
 423
 424#endif
 425