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 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
  92extern 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
  99struct completion;
 100struct pt_regs;
 101struct 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
 114extern 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
 135extern struct atomic_notifier_head panic_notifier_list;
 136extern long (*panic_blink)(long time);
 137NORET_TYPE void panic(const char * fmt, ...)
 138        __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 139extern void oops_enter(void);
 140extern void oops_exit(void);
 141extern int oops_may_print(void);
 142NORET_TYPE void do_exit(long error_code)
 143        ATTRIB_NORET;
 144NORET_TYPE void complete_and_exit(struct completion *, long)
 145        ATTRIB_NORET;
 146extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 147extern long simple_strtol(const char *,char **,unsigned int);
 148extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 149extern long long simple_strtoll(const char *,char **,unsigned int);
 150extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 151extern int strict_strtol(const char *, unsigned int, long *);
 152extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 153extern int strict_strtoll(const char *, unsigned int, long long *);
 154extern int sprintf(char * buf, const char * fmt, ...)
 155        __attribute__ ((format (printf, 2, 3)));
 156extern int vsprintf(char *buf, const char *, va_list)
 157        __attribute__ ((format (printf, 2, 0)));
 158extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 159        __attribute__ ((format (printf, 3, 4)));
 160extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 161        __attribute__ ((format (printf, 3, 0)));
 162extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 163        __attribute__ ((format (printf, 3, 4)));
 164extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 165        __attribute__ ((format (printf, 3, 0)));
 166extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 167        __attribute__ ((format (printf, 2, 3)));
 168extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 169
 170extern int sscanf(const char *, const char *, ...)
 171        __attribute__ ((format (scanf, 2, 3)));
 172extern int vsscanf(const char *, const char *, va_list)
 173        __attribute__ ((format (scanf, 2, 0)));
 174
 175extern int get_option(char **str, int *pint);
 176extern char *get_options(const char *str, int nints, int *ints);
 177extern unsigned long long memparse(char *ptr, char **retptr);
 178
 179extern int core_kernel_text(unsigned long addr);
 180extern int __kernel_text_address(unsigned long addr);
 181extern int kernel_text_address(unsigned long addr);
 182struct pid;
 183extern struct pid *session_of_pgrp(struct pid *pgrp);
 184
 185#ifdef CONFIG_PRINTK
 186asmlinkage int vprintk(const char *fmt, va_list args)
 187        __attribute__ ((format (printf, 1, 0)));
 188asmlinkage int printk(const char * fmt, ...)
 189        __attribute__ ((format (printf, 1, 2))) __cold;
 190extern int log_buf_get_len(void);
 191extern int log_buf_read(int idx);
 192extern int log_buf_copy(char *dest, int idx, int len);
 193
 194extern int printk_ratelimit_jiffies;
 195extern int printk_ratelimit_burst;
 196extern int printk_ratelimit(void);
 197extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 198extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 199extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 200                                   unsigned int interval_msec);
 201#else
 202static inline int vprintk(const char *s, va_list args)
 203        __attribute__ ((format (printf, 1, 0)));
 204static inline int vprintk(const char *s, va_list args) { return 0; }
 205static inline int printk(const char *s, ...)
 206        __attribute__ ((format (printf, 1, 2)));
 207static inline int __cold printk(const char *s, ...) { return 0; }
 208static inline int log_buf_get_len(void) { return 0; }
 209static inline int log_buf_read(int idx) { return 0; }
 210static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
 211static inline int printk_ratelimit(void) { return 0; }
 212static inline int __printk_ratelimit(int ratelimit_jiffies, \
 213                                     int ratelimit_burst) { return 0; }
 214static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 215                                          unsigned int interval_msec)   \
 216                { return false; }
 217#endif
 218
 219extern void __attribute__((format(printf, 1, 2)))
 220        early_printk(const char *fmt, ...);
 221
 222unsigned long int_sqrt(unsigned long);
 223
 224static inline void console_silent(void)
 225{
 226        console_loglevel = 0;
 227}
 228
 229static inline void console_verbose(void)
 230{
 231        if (console_loglevel)
 232                console_loglevel = 15;
 233}
 234
 235extern void bust_spinlocks(int yes);
 236extern void wake_up_klogd(void);
 237extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 238extern int panic_timeout;
 239extern int panic_on_oops;
 240extern int panic_on_unrecovered_nmi;
 241extern int tainted;
 242extern const char *print_tainted(void);
 243extern void add_taint(unsigned);
 244extern int root_mountflags;
 245
 246/* Values used for system_state */
 247extern 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
 267extern void dump_stack(void) __cold;
 268
 269enum {
 270        DUMP_PREFIX_NONE,
 271        DUMP_PREFIX_ADDRESS,
 272        DUMP_PREFIX_OFFSET
 273};
 274extern void hex_dump_to_buffer(const void *buf, size_t len,
 275                                int rowsize, int groupsize,
 276                                char *linebuf, size_t linebuflen, bool ascii);
 277extern 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);
 280extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 281                        const void *buf, size_t len);
 282
 283extern 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
 287static 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
 470struct sysinfo;
 471extern int do_sysinfo(struct sysinfo *info);
 472
 473#endif /* __KERNEL__ */
 474
 475#define SI_LOAD_SHIFT   16
 476struct 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
 513
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