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 <linux/typecheck.h>
  18#include <linux/ratelimit.h>
  19#include <asm/byteorder.h>
  20#include <asm/bug.h>
  21
  22extern const char linux_banner[];
  23extern 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/**
  79 * lower_32_bits - return bits 0-31 of a number
  80 * @n: the number we're accessing
  81 */
  82#define lower_32_bits(n) ((u32)(n))
  83
  84#define KERN_EMERG      "<0>"   /* system is unusable                   */
  85#define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  86#define KERN_CRIT       "<2>"   /* critical conditions                  */
  87#define KERN_ERR        "<3>"   /* error conditions                     */
  88#define KERN_WARNING    "<4>"   /* warning conditions                   */
  89#define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  90#define KERN_INFO       "<6>"   /* informational                        */
  91#define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  92
  93/*
  94 * Annotation for a "continued" line of log printout (only done after a
  95 * line that had no enclosing \n). Only to be used by core/arch code
  96 * during early bootup (a continued line is not SMP-safe otherwise).
  97 */
  98#define KERN_CONT       ""
  99
 100extern int console_printk[];
 101
 102#define console_loglevel (console_printk[0])
 103#define default_message_loglevel (console_printk[1])
 104#define minimum_console_loglevel (console_printk[2])
 105#define default_console_loglevel (console_printk[3])
 106
 107struct completion;
 108struct pt_regs;
 109struct user;
 110
 111#ifdef CONFIG_PREEMPT_VOLUNTARY
 112extern int _cond_resched(void);
 113# define might_resched() _cond_resched()
 114#else
 115# define might_resched() do { } while (0)
 116#endif
 117
 118/**
 119 * might_sleep - annotation for functions that can sleep
 120 *
 121 * this macro will print a stack trace if it is executed in an atomic
 122 * context (spinlock, irq-handler, ...).
 123 *
 124 * This is a useful debugging help to be able to catch problems early and not
 125 * be bitten later when the calling function happens to sleep when it is not
 126 * supposed to.
 127 */
 128#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 129  void __might_sleep(char *file, int line);
 130# define might_sleep() \
 131        do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 132#else
 133# define might_sleep() do { might_resched(); } while (0)
 134#endif
 135
 136#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 137
 138#define abs(x) ({                               \
 139                int __x = (x);                  \
 140                (__x < 0) ? -__x : __x;         \
 141        })
 142
 143extern struct atomic_notifier_head panic_notifier_list;
 144extern long (*panic_blink)(long time);
 145NORET_TYPE void panic(const char * fmt, ...)
 146        __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 147extern void oops_enter(void);
 148extern void oops_exit(void);
 149extern int oops_may_print(void);
 150NORET_TYPE void do_exit(long error_code)
 151        ATTRIB_NORET;
 152NORET_TYPE void complete_and_exit(struct completion *, long)
 153        ATTRIB_NORET;
 154extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 155extern long simple_strtol(const char *,char **,unsigned int);
 156extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 157extern long long simple_strtoll(const char *,char **,unsigned int);
 158extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 159extern int strict_strtol(const char *, unsigned int, long *);
 160extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 161extern int strict_strtoll(const char *, unsigned int, long long *);
 162extern int sprintf(char * buf, const char * fmt, ...)
 163        __attribute__ ((format (printf, 2, 3)));
 164extern int vsprintf(char *buf, const char *, va_list)
 165        __attribute__ ((format (printf, 2, 0)));
 166extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 167        __attribute__ ((format (printf, 3, 4)));
 168extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 169        __attribute__ ((format (printf, 3, 0)));
 170extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 171        __attribute__ ((format (printf, 3, 4)));
 172extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 173        __attribute__ ((format (printf, 3, 0)));
 174extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 175        __attribute__ ((format (printf, 2, 3)));
 176extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 177
 178extern int sscanf(const char *, const char *, ...)
 179        __attribute__ ((format (scanf, 2, 3)));
 180extern int vsscanf(const char *, const char *, va_list)
 181        __attribute__ ((format (scanf, 2, 0)));
 182
 183extern int get_option(char **str, int *pint);
 184extern char *get_options(const char *str, int nints, int *ints);
 185extern unsigned long long memparse(char *ptr, char **retptr);
 186
 187extern int core_kernel_text(unsigned long addr);
 188extern int __kernel_text_address(unsigned long addr);
 189extern int kernel_text_address(unsigned long addr);
 190struct pid;
 191extern struct pid *session_of_pgrp(struct pid *pgrp);
 192
 193#ifdef CONFIG_PRINTK
 194asmlinkage int vprintk(const char *fmt, va_list args)
 195        __attribute__ ((format (printf, 1, 0)));
 196asmlinkage int printk(const char * fmt, ...)
 197        __attribute__ ((format (printf, 1, 2))) __cold;
 198
 199extern struct ratelimit_state printk_ratelimit_state;
 200extern int printk_ratelimit(void);
 201extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 202                                   unsigned int interval_msec);
 203#else
 204static inline int vprintk(const char *s, va_list args)
 205        __attribute__ ((format (printf, 1, 0)));
 206static inline int vprintk(const char *s, va_list args) { return 0; }
 207static inline int printk(const char *s, ...)
 208        __attribute__ ((format (printf, 1, 2)));
 209static inline int __cold printk(const char *s, ...) { return 0; }
 210static inline int printk_ratelimit(void) { return 0; }
 211static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 212                                          unsigned int interval_msec)   \
 213                { return false; }
 214#endif
 215
 216extern void asmlinkage __attribute__((format(printf, 1, 2)))
 217        early_printk(const char *fmt, ...);
 218
 219unsigned long int_sqrt(unsigned long);
 220
 221static inline void console_silent(void)
 222{
 223        console_loglevel = 0;
 224}
 225
 226static inline void console_verbose(void)
 227{
 228        if (console_loglevel)
 229                console_loglevel = 15;
 230}
 231
 232extern void bust_spinlocks(int yes);
 233extern void wake_up_klogd(void);
 234extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 235extern int panic_timeout;
 236extern int panic_on_oops;
 237extern int panic_on_unrecovered_nmi;
 238extern int tainted;
 239extern const char *print_tainted(void);
 240extern void add_taint(unsigned);
 241extern int root_mountflags;
 242
 243/* Values used for system_state */
 244extern 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
 264extern void dump_stack(void) __cold;
 265
 266enum {
 267        DUMP_PREFIX_NONE,
 268        DUMP_PREFIX_ADDRESS,
 269        DUMP_PREFIX_OFFSET
 270};
 271extern void hex_dump_to_buffer(const void *buf, size_t len,
 272                                int rowsize, int groupsize,
 273                                char *linebuf, size_t linebuflen, bool ascii);
 274extern 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);
 277extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 278                        const void *buf, size_t len);
 279
 280extern 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
 284static 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
 447struct sysinfo;
 448extern int do_sysinfo(struct sysinfo *info);
 449
 450#endif /* __KERNEL__ */
 451
 452#define SI_LOAD_SHIFT   16
 453struct sysinfo {
 454        long uptime;                    /* Seconds since boot */
 455        unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 456        unsigned long totalram;         /* Total usable main memory size */
 457        unsigned long freeram;          /* Available memory size */
 458        unsigned long sharedram;        /* Amount of shared memory */
 459        unsigned long bufferram;        /* Memory used by buffers */
 460        unsigned long totalswap;        /* Total swap space size */
 461        unsigned long freeswap;         /* swap space still available */
 462        unsigned short procs;           /* Number of current processes */
 463        unsigned short pad;             /* explicit padding for m68k */
 464        unsigned long totalhigh;        /* Total high memory size */
 465        unsigned long freehigh;         /* Available high memory size */
 466        unsigned int mem_unit;          /* Memory unit size in bytes */
 467        char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 468};
 469
 470/* Force a compilation error if condition is true */
 471#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 472
 473/* Force a compilation error if condition is true, but also produce a
 474   result (of value 0 and type size_t), so the expression can be used
 475   e.g. in a structure initializer (or where-ever else comma expressions
 476   aren't permitted). */
 477#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 478
 479/* Trap pasters of __FUNCTION__ at compile-time */
 480#define __FUNCTION__ (__func__)
 481
 482/* This helps us to avoid #ifdef CONFIG_NUMA */
 483#ifdef CONFIG_NUMA
 484#define NUMA_BUILD 1
 485#else
 486#define NUMA_BUILD 0
 487#endif
 488
 489#endif
 490
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