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 <linux/dynamic_printk.h>
  20#include <asm/byteorder.h>
  21#include <asm/bug.h>
  22
  23extern const char linux_banner[];
  24extern const char linux_proc_banner[];
  25
  26#define USHORT_MAX      ((u16)(~0U))
  27#define SHORT_MAX       ((s16)(USHORT_MAX>>1))
  28#define SHORT_MIN       (-SHORT_MAX - 1)
  29#define INT_MAX         ((int)(~0U>>1))
  30#define INT_MIN         (-INT_MAX - 1)
  31#define UINT_MAX        (~0U)
  32#define LONG_MAX        ((long)(~0UL>>1))
  33#define LONG_MIN        (-LONG_MAX - 1)
  34#define ULONG_MAX       (~0UL)
  35#define LLONG_MAX       ((long long)(~0ULL>>1))
  36#define LLONG_MIN       (-LLONG_MAX - 1)
  37#define ULLONG_MAX      (~0ULL)
  38
  39#define STACK_MAGIC     0xdeadbeef
  40
  41#define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  42#define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  43#define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  44#define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  45
  46#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  47
  48#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  49#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  50#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  51#define DIV_ROUND_CLOSEST(x, divisor)(                  \
  52{                                                       \
  53        typeof(divisor) __divisor = divisor;            \
  54        (((x) + ((__divisor) / 2)) / (__divisor));      \
  55}                                                       \
  56)
  57
  58#define _RET_IP_                (unsigned long)__builtin_return_address(0)
  59#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
  60
  61#ifdef CONFIG_LBD
  62# include <asm/div64.h>
  63# define sector_div(a, b) do_div(a, b)
  64#else
  65# define sector_div(n, b)( \
  66{ \
  67        int _res; \
  68        _res = (n) % (b); \
  69        (n) /= (b); \
  70        _res; \
  71} \
  72)
  73#endif
  74
  75/**
  76 * upper_32_bits - return bits 32-63 of a number
  77 * @n: the number we're accessing
  78 *
  79 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  80 * the "right shift count >= width of type" warning when that quantity is
  81 * 32-bits.
  82 */
  83#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  84
  85/**
  86 * lower_32_bits - return bits 0-31 of a number
  87 * @n: the number we're accessing
  88 */
  89#define lower_32_bits(n) ((u32)(n))
  90
  91#define KERN_EMERG      "<0>"   /* system is unusable                   */
  92#define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  93#define KERN_CRIT       "<2>"   /* critical conditions                  */
  94#define KERN_ERR        "<3>"   /* error conditions                     */
  95#define KERN_WARNING    "<4>"   /* warning conditions                   */
  96#define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  97#define KERN_INFO       "<6>"   /* informational                        */
  98#define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  99
 100/*
 101 * Annotation for a "continued" line of log printout (only done after a
 102 * line that had no enclosing \n). Only to be used by core/arch code
 103 * during early bootup (a continued line is not SMP-safe otherwise).
 104 */
 105#define KERN_CONT       ""
 106
 107extern int console_printk[];
 108
 109#define console_loglevel (console_printk[0])
 110#define default_message_loglevel (console_printk[1])
 111#define minimum_console_loglevel (console_printk[2])
 112#define default_console_loglevel (console_printk[3])
 113
 114struct completion;
 115struct pt_regs;
 116struct user;
 117
 118#ifdef CONFIG_PREEMPT_VOLUNTARY
 119extern int _cond_resched(void);
 120# define might_resched() _cond_resched()
 121#else
 122# define might_resched() do { } while (0)
 123#endif
 124
 125#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 126  void __might_sleep(char *file, int line);
 127/**
 128 * might_sleep - annotation for functions that can sleep
 129 *
 130 * this macro will print a stack trace if it is executed in an atomic
 131 * context (spinlock, irq-handler, ...).
 132 *
 133 * This is a useful debugging help to be able to catch problems early and not
 134 * be bitten later when the calling function happens to sleep when it is not
 135 * supposed to.
 136 */
 137# define might_sleep() \
 138        do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 139#else
 140# define might_sleep() do { might_resched(); } while (0)
 141#endif
 142
 143#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 144
 145#define abs(x) ({                               \
 146                int __x = (x);                  \
 147                (__x < 0) ? -__x : __x;         \
 148        })
 149
 150#ifdef CONFIG_PROVE_LOCKING
 151void might_fault(void);
 152#else
 153static inline void might_fault(void)
 154{
 155        might_sleep();
 156}
 157#endif
 158
 159extern struct atomic_notifier_head panic_notifier_list;
 160extern long (*panic_blink)(long time);
 161NORET_TYPE void panic(const char * fmt, ...)
 162        __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 163extern void oops_enter(void);
 164extern void oops_exit(void);
 165extern int oops_may_print(void);
 166NORET_TYPE void do_exit(long error_code)
 167        ATTRIB_NORET;
 168NORET_TYPE void complete_and_exit(struct completion *, long)
 169        ATTRIB_NORET;
 170extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 171extern long simple_strtol(const char *,char **,unsigned int);
 172extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 173extern long long simple_strtoll(const char *,char **,unsigned int);
 174extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 175extern int strict_strtol(const char *, unsigned int, long *);
 176extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 177extern int strict_strtoll(const char *, unsigned int, long long *);
 178extern int sprintf(char * buf, const char * fmt, ...)
 179        __attribute__ ((format (printf, 2, 3)));
 180extern int vsprintf(char *buf, const char *, va_list)
 181        __attribute__ ((format (printf, 2, 0)));
 182extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 183        __attribute__ ((format (printf, 3, 4)));
 184extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 185        __attribute__ ((format (printf, 3, 0)));
 186extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 187        __attribute__ ((format (printf, 3, 4)));
 188extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 189        __attribute__ ((format (printf, 3, 0)));
 190extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 191        __attribute__ ((format (printf, 2, 3)));
 192extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 193
 194extern int sscanf(const char *, const char *, ...)
 195        __attribute__ ((format (scanf, 2, 3)));
 196extern int vsscanf(const char *, const char *, va_list)
 197        __attribute__ ((format (scanf, 2, 0)));
 198
 199extern int get_option(char **str, int *pint);
 200extern char *get_options(const char *str, int nints, int *ints);
 201extern unsigned long long memparse(const char *ptr, char **retptr);
 202
 203extern int core_kernel_text(unsigned long addr);
 204extern int __kernel_text_address(unsigned long addr);
 205extern int kernel_text_address(unsigned long addr);
 206extern int func_ptr_is_kernel_text(void *ptr);
 207
 208struct pid;
 209extern struct pid *session_of_pgrp(struct pid *pgrp);
 210
 211/*
 212 * FW_BUG
 213 * Add this to a message where you are sure the firmware is buggy or behaves
 214 * really stupid or out of spec. Be aware that the responsible BIOS developer
 215 * should be able to fix this issue or at least get a concrete idea of the
 216 * problem by reading your message without the need of looking at the kernel
 217 * code.
 218 * 
 219 * Use it for definite and high priority BIOS bugs.
 220 *
 221 * FW_WARN
 222 * Use it for not that clear (e.g. could the kernel messed up things already?)
 223 * and medium priority BIOS bugs.
 224 *
 225 * FW_INFO
 226 * Use this one if you want to tell the user or vendor about something
 227 * suspicious, but generally harmless related to the firmware.
 228 *
 229 * Use it for information or very low priority BIOS bugs.
 230 */
 231#define FW_BUG          "[Firmware Bug]: "
 232#define FW_WARN         "[Firmware Warn]: "
 233#define FW_INFO         "[Firmware Info]: "
 234
 235#ifdef CONFIG_PRINTK
 236asmlinkage int vprintk(const char *fmt, va_list args)
 237        __attribute__ ((format (printf, 1, 0)));
 238asmlinkage int printk(const char * fmt, ...)
 239        __attribute__ ((format (printf, 1, 2))) __cold;
 240
 241extern struct ratelimit_state printk_ratelimit_state;
 242extern int printk_ratelimit(void);
 243extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 244                                   unsigned int interval_msec);
 245#else
 246static inline int vprintk(const char *s, va_list args)
 247        __attribute__ ((format (printf, 1, 0)));
 248static inline int vprintk(const char *s, va_list args) { return 0; }
 249static inline int printk(const char *s, ...)
 250        __attribute__ ((format (printf, 1, 2)));
 251static inline int __cold printk(const char *s, ...) { return 0; }
 252static inline int printk_ratelimit(void) { return 0; }
 253static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 254                                          unsigned int interval_msec)   \
 255                { return false; }
 256#endif
 257
 258extern int printk_needs_cpu(int cpu);
 259extern void printk_tick(void);
 260
 261extern void asmlinkage __attribute__((format(printf, 1, 2)))
 262        early_printk(const char *fmt, ...);
 263
 264unsigned long int_sqrt(unsigned long);
 265
 266static inline void console_silent(void)
 267{
 268        console_loglevel = 0;
 269}
 270
 271static inline void console_verbose(void)
 272{
 273        if (console_loglevel)
 274                console_loglevel = 15;
 275}
 276
 277extern void bust_spinlocks(int yes);
 278extern void wake_up_klogd(void);
 279extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 280extern int panic_timeout;
 281extern int panic_on_oops;
 282extern int panic_on_unrecovered_nmi;
 283extern const char *print_tainted(void);
 284extern void add_taint(unsigned flag);
 285extern int test_taint(unsigned flag);
 286extern unsigned long get_taint(void);
 287extern int root_mountflags;
 288
 289/* Values used for system_state */
 290extern enum system_states {
 291        SYSTEM_BOOTING,
 292        SYSTEM_RUNNING,
 293        SYSTEM_HALT,
 294        SYSTEM_POWER_OFF,
 295        SYSTEM_RESTART,
 296        SYSTEM_SUSPEND_DISK,
 297} system_state;
 298
 299#define TAINT_PROPRIETARY_MODULE        0
 300#define TAINT_FORCED_MODULE             1
 301#define TAINT_UNSAFE_SMP                2
 302#define TAINT_FORCED_RMMOD              3
 303#define TAINT_MACHINE_CHECK             4
 304#define TAINT_BAD_PAGE                  5
 305#define TAINT_USER                      6
 306#define TAINT_DIE                       7
 307#define TAINT_OVERRIDDEN_ACPI_TABLE     8
 308#define TAINT_WARN                      9
 309#define TAINT_CRAP                      10
 310
 311extern void dump_stack(void) __cold;
 312
 313enum {
 314        DUMP_PREFIX_NONE,
 315        DUMP_PREFIX_ADDRESS,
 316        DUMP_PREFIX_OFFSET
 317};
 318extern void hex_dump_to_buffer(const void *buf, size_t len,
 319                                int rowsize, int groupsize,
 320                                char *linebuf, size_t linebuflen, bool ascii);
 321extern void print_hex_dump(const char *level, const char *prefix_str,
 322                                int prefix_type, int rowsize, int groupsize,
 323                                const void *buf, size_t len, bool ascii);
 324extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 325                        const void *buf, size_t len);
 326
 327extern const char hex_asc[];
 328#define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 329#define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 330
 331static inline char *pack_hex_byte(char *buf, u8 byte)
 332{
 333        *buf++ = hex_asc_hi(byte);
 334        *buf++ = hex_asc_lo(byte);
 335        return buf;
 336}
 337
 338#ifndef pr_fmt
 339#define pr_fmt(fmt) fmt
 340#endif
 341
 342#define pr_emerg(fmt, ...) \
 343        printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 344#define pr_alert(fmt, ...) \
 345        printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 346#define pr_crit(fmt, ...) \
 347        printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 348#define pr_err(fmt, ...) \
 349        printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 350#define pr_warning(fmt, ...) \
 351        printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 352#define pr_notice(fmt, ...) \
 353        printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 354#define pr_info(fmt, ...) \
 355        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 356
 357/* If you are writing a driver, please use dev_dbg instead */
 358#if defined(DEBUG)
 359#define pr_debug(fmt, ...) \
 360        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 361#elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
 362#define pr_debug(fmt, ...) do { \
 363        dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
 364        } while (0)
 365#else
 366#define pr_debug(fmt, ...) \
 367        ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
 368#endif
 369
 370/*
 371 *      Display an IP address in readable format.
 372 */
 373
 374#define NIPQUAD(addr) \
 375        ((unsigned char *)&addr)[0], \
 376        ((unsigned char *)&addr)[1], \
 377        ((unsigned char *)&addr)[2], \
 378        ((unsigned char *)&addr)[3]
 379#define NIPQUAD_FMT "%u.%u.%u.%u"
 380
 381#if defined(__LITTLE_ENDIAN)
 382#define HIPQUAD(addr) \
 383        ((unsigned char *)&addr)[3], \
 384        ((unsigned char *)&addr)[2], \
 385        ((unsigned char *)&addr)[1], \
 386        ((unsigned char *)&addr)[0]
 387#elif defined(__BIG_ENDIAN)
 388#define HIPQUAD NIPQUAD
 389#else
 390#error "Please fix asm/byteorder.h"
 391#endif /* __LITTLE_ENDIAN */
 392
 393/*
 394 * min()/max()/clamp() macros that also do
 395 * strict type-checking.. See the
 396 * "unnecessary" pointer comparison.
 397 */
 398#define min(x, y) ({                            \
 399        typeof(x) _min1 = (x);                  \
 400        typeof(y) _min2 = (y);                  \
 401        (void) (&_min1 == &_min2);              \
 402        _min1 < _min2 ? _min1 : _min2; })
 403
 404#define max(x, y) ({                            \
 405        typeof(x) _max1 = (x);                  \
 406        typeof(y) _max2 = (y);                  \
 407        (void) (&_max1 == &_max2);              \
 408        _max1 > _max2 ? _max1 : _max2; })
 409
 410/**
 411 * clamp - return a value clamped to a given range with strict typechecking
 412 * @val: current value
 413 * @min: minimum allowable value
 414 * @max: maximum allowable value
 415 *
 416 * This macro does strict typechecking of min/max to make sure they are of the
 417 * same type as val.  See the unnecessary pointer comparisons.
 418 */
 419#define clamp(val, min, max) ({                 \
 420        typeof(val) __val = (val);              \
 421        typeof(min) __min = (min);              \
 422        typeof(max) __max = (max);              \
 423        (void) (&__val == &__min);              \
 424        (void) (&__val == &__max);              \
 425        __val = __val < __min ? __min: __val;   \
 426        __val > __max ? __max: __val; })
 427
 428/*
 429 * ..and if you can't take the strict
 430 * types, you can specify one yourself.
 431 *
 432 * Or not use min/max/clamp at all, of course.
 433 */
 434#define min_t(type, x, y) ({                    \
 435        type __min1 = (x);                      \
 436        type __min2 = (y);                      \
 437        __min1 < __min2 ? __min1: __min2; })
 438
 439#define max_t(type, x, y) ({                    \
 440        type __max1 = (x);                      \
 441        type __max2 = (y);                      \
 442        __max1 > __max2 ? __max1: __max2; })
 443
 444/**
 445 * clamp_t - return a value clamped to a given range using a given type
 446 * @type: the type of variable to use
 447 * @val: current value
 448 * @min: minimum allowable value
 449 * @max: maximum allowable value
 450 *
 451 * This macro does no typechecking and uses temporary variables of type
 452 * 'type' to make all the comparisons.
 453 */
 454#define clamp_t(type, val, min, max) ({         \
 455        type __val = (val);                     \
 456        type __min = (min);                     \
 457        type __max = (max);                     \
 458        __val = __val < __min ? __min: __val;   \
 459        __val > __max ? __max: __val; })
 460
 461/**
 462 * clamp_val - return a value clamped to a given range using val's type
 463 * @val: current value
 464 * @min: minimum allowable value
 465 * @max: maximum allowable value
 466 *
 467 * This macro does no typechecking and uses temporary variables of whatever
 468 * type the input argument 'val' is.  This is useful when val is an unsigned
 469 * type and min and max are literals that will otherwise be assigned a signed
 470 * integer type.
 471 */
 472#define clamp_val(val, min, max) ({             \
 473        typeof(val) __val = (val);              \
 474        typeof(val) __min = (min);              \
 475        typeof(val) __max = (max);              \
 476        __val = __val < __min ? __min: __val;   \
 477        __val > __max ? __max: __val; })
 478
 479
 480/*
 481 * swap - swap value of @a and @b
 482 */
 483#define swap(a, b) \
 484        do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 485
 486/**
 487 * container_of - cast a member of a structure out to the containing structure
 488 * @ptr:        the pointer to the member.
 489 * @type:       the type of the container struct this is embedded in.
 490 * @member:     the name of the member within the struct.
 491 *
 492 */
 493#define container_of(ptr, type, member) ({                      \
 494        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 495        (type *)( (char *)__mptr - offsetof(type,member) );})
 496
 497struct sysinfo;
 498extern int do_sysinfo(struct sysinfo *info);
 499
 500#endif /* __KERNEL__ */
 501
 502#define SI_LOAD_SHIFT   16
 503struct sysinfo {
 504        long uptime;                    /* Seconds since boot */
 505        unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 506        unsigned long totalram;         /* Total usable main memory size */
 507        unsigned long freeram;          /* Available memory size */
 508        unsigned long sharedram;        /* Amount of shared memory */
 509        unsigned long bufferram;        /* Memory used by buffers */
 510        unsigned long totalswap;        /* Total swap space size */
 511        unsigned long freeswap;         /* swap space still available */
 512        unsigned short procs;           /* Number of current processes */
 513        unsigned short pad;             /* explicit padding for m68k */
 514        unsigned long totalhigh;        /* Total high memory size */
 515        unsigned long freehigh;         /* Available high memory size */
 516        unsigned int mem_unit;          /* Memory unit size in bytes */
 517        char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 518};
 519
 520/* Force a compilation error if condition is true */
 521#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 522
 523/* Force a compilation error if condition is true, but also produce a
 524   result (of value 0 and type size_t), so the expression can be used
 525   e.g. in a structure initializer (or where-ever else comma expressions
 526   aren't permitted). */
 527#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 528
 529/* Trap pasters of __FUNCTION__ at compile-time */
 530#define __FUNCTION__ (__func__)
 531
 532/* This helps us to avoid #ifdef CONFIG_NUMA */
 533#ifdef CONFIG_NUMA
 534#define NUMA_BUILD 1
 535#else
 536#define NUMA_BUILD 0
 537#endif
 538
 539/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 540#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 541# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 542#endif
 543
 544#endif
 545
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