linux/include/linux/kernel.h
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   1#ifndef _LINUX_KERNEL_H
   2#define _LINUX_KERNEL_H
   3
   4
   5#include <stdarg.h>
   6#include <linux/linkage.h>
   7#include <linux/stddef.h>
   8#include <linux/types.h>
   9#include <linux/compiler.h>
  10#include <linux/bitops.h>
  11#include <linux/log2.h>
  12#include <linux/typecheck.h>
  13#include <linux/printk.h>
  14#include <linux/dynamic_debug.h>
  15#include <asm/byteorder.h>
  16#include <uapi/linux/kernel.h>
  17
  18#define USHRT_MAX       ((u16)(~0U))
  19#define SHRT_MAX        ((s16)(USHRT_MAX>>1))
  20#define SHRT_MIN        ((s16)(-SHRT_MAX - 1))
  21#define INT_MAX         ((int)(~0U>>1))
  22#define INT_MIN         (-INT_MAX - 1)
  23#define UINT_MAX        (~0U)
  24#define LONG_MAX        ((long)(~0UL>>1))
  25#define LONG_MIN        (-LONG_MAX - 1)
  26#define ULONG_MAX       (~0UL)
  27#define LLONG_MAX       ((long long)(~0ULL>>1))
  28#define LLONG_MIN       (-LLONG_MAX - 1)
  29#define ULLONG_MAX      (~0ULL)
  30#define SIZE_MAX        (~(size_t)0)
  31
  32#define U8_MAX          ((u8)~0U)
  33#define S8_MAX          ((s8)(U8_MAX>>1))
  34#define S8_MIN          ((s8)(-S8_MAX - 1))
  35#define U16_MAX         ((u16)~0U)
  36#define S16_MAX         ((s16)(U16_MAX>>1))
  37#define S16_MIN         ((s16)(-S16_MAX - 1))
  38#define U32_MAX         ((u32)~0U)
  39#define S32_MAX         ((s32)(U32_MAX>>1))
  40#define S32_MIN         ((s32)(-S32_MAX - 1))
  41#define U64_MAX         ((u64)~0ULL)
  42#define S64_MAX         ((s64)(U64_MAX>>1))
  43#define S64_MIN         ((s64)(-S64_MAX - 1))
  44
  45#define STACK_MAGIC     0xdeadbeef
  46
  47#define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
  48
  49#define ALIGN(x, a)             __ALIGN_KERNEL((x), (a))
  50#define __ALIGN_MASK(x, mask)   __ALIGN_KERNEL_MASK((x), (mask))
  51#define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  52#define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  53
  54#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  55
  56#define u64_to_user_ptr(x) (            \
  57{                                       \
  58        typecheck(u64, x);              \
  59        (void __user *)(uintptr_t)x;    \
  60}                                       \
  61)
  62
  63/*
  64 * This looks more complex than it should be. But we need to
  65 * get the type for the ~ right in round_down (it needs to be
  66 * as wide as the result!), and we want to evaluate the macro
  67 * arguments just once each.
  68 */
  69#define __round_mask(x, y) ((__typeof__(x))((y)-1))
  70#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
  71#define round_down(x, y) ((x) & ~__round_mask(x, y))
  72
  73#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  74#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
  75#define DIV_ROUND_UP_ULL(ll,d) \
  76        ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
  77
  78#if BITS_PER_LONG == 32
  79# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
  80#else
  81# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
  82#endif
  83
  84/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
  85#define roundup(x, y) (                                 \
  86{                                                       \
  87        const typeof(y) __y = y;                        \
  88        (((x) + (__y - 1)) / __y) * __y;                \
  89}                                                       \
  90)
  91#define rounddown(x, y) (                               \
  92{                                                       \
  93        typeof(x) __x = (x);                            \
  94        __x - (__x % (y));                              \
  95}                                                       \
  96)
  97
  98/*
  99 * Divide positive or negative dividend by positive divisor and round
 100 * to closest integer. Result is undefined for negative divisors and
 101 * for negative dividends if the divisor variable type is unsigned.
 102 */
 103#define DIV_ROUND_CLOSEST(x, divisor)(                  \
 104{                                                       \
 105        typeof(x) __x = x;                              \
 106        typeof(divisor) __d = divisor;                  \
 107        (((typeof(x))-1) > 0 ||                         \
 108         ((typeof(divisor))-1) > 0 || (__x) > 0) ?      \
 109                (((__x) + ((__d) / 2)) / (__d)) :       \
 110                (((__x) - ((__d) / 2)) / (__d));        \
 111}                                                       \
 112)
 113/*
 114 * Same as above but for u64 dividends. divisor must be a 32-bit
 115 * number.
 116 */
 117#define DIV_ROUND_CLOSEST_ULL(x, divisor)(              \
 118{                                                       \
 119        typeof(divisor) __d = divisor;                  \
 120        unsigned long long _tmp = (x) + (__d) / 2;      \
 121        do_div(_tmp, __d);                              \
 122        _tmp;                                           \
 123}                                                       \
 124)
 125
 126/*
 127 * Multiplies an integer by a fraction, while avoiding unnecessary
 128 * overflow or loss of precision.
 129 */
 130#define mult_frac(x, numer, denom)(                     \
 131{                                                       \
 132        typeof(x) quot = (x) / (denom);                 \
 133        typeof(x) rem  = (x) % (denom);                 \
 134        (quot * (numer)) + ((rem * (numer)) / (denom)); \
 135}                                                       \
 136)
 137
 138
 139#define _RET_IP_                (unsigned long)__builtin_return_address(0)
 140#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
 141
 142#ifdef CONFIG_LBDAF
 143# include <asm/div64.h>
 144# define sector_div(a, b) do_div(a, b)
 145#else
 146# define sector_div(n, b)( \
 147{ \
 148        int _res; \
 149        _res = (n) % (b); \
 150        (n) /= (b); \
 151        _res; \
 152} \
 153)
 154#endif
 155
 156/**
 157 * upper_32_bits - return bits 32-63 of a number
 158 * @n: the number we're accessing
 159 *
 160 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
 161 * the "right shift count >= width of type" warning when that quantity is
 162 * 32-bits.
 163 */
 164#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
 165
 166/**
 167 * lower_32_bits - return bits 0-31 of a number
 168 * @n: the number we're accessing
 169 */
 170#define lower_32_bits(n) ((u32)(n))
 171
 172struct completion;
 173struct pt_regs;
 174struct user;
 175
 176#ifdef CONFIG_PREEMPT_VOLUNTARY
 177extern int _cond_resched(void);
 178# define might_resched() _cond_resched()
 179#else
 180# define might_resched() do { } while (0)
 181#endif
 182
 183#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 184  void __might_sleep(const char *file, int line, int preempt_offset);
 185/**
 186 * might_sleep - annotation for functions that can sleep
 187 *
 188 * this macro will print a stack trace if it is executed in an atomic
 189 * context (spinlock, irq-handler, ...).
 190 *
 191 * This is a useful debugging help to be able to catch problems early and not
 192 * be bitten later when the calling function happens to sleep when it is not
 193 * supposed to.
 194 */
 195# define might_sleep() \
 196        do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 197#else
 198  static inline void __might_sleep(const char *file, int line,
 199                                   int preempt_offset) { }
 200# define might_sleep() do { might_resched(); } while (0)
 201#endif
 202
 203#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 204
 205/**
 206 * abs - return absolute value of an argument
 207 * @x: the value.  If it is unsigned type, it is converted to signed type first
 208 *   (s64, long or int depending on its size).
 209 *
 210 * Return: an absolute value of x.  If x is 64-bit, macro's return type is s64,
 211 *   otherwise it is signed long.
 212 */
 213#define abs(x) __builtin_choose_expr(sizeof(x) == sizeof(s64), ({       \
 214                s64 __x = (x);                                          \
 215                (__x < 0) ? -__x : __x;                                 \
 216        }), ({                                                          \
 217                long ret;                                               \
 218                if (sizeof(x) == sizeof(long)) {                        \
 219                        long __x = (x);                                 \
 220                        ret = (__x < 0) ? -__x : __x;                   \
 221                } else {                                                \
 222                        int __x = (x);                                  \
 223                        ret = (__x < 0) ? -__x : __x;                   \
 224                }                                                       \
 225                ret;                                                    \
 226        }))
 227
 228/* Deprecated, use abs instead. */
 229#define abs64(x) abs((s64)(x))
 230
 231/**
 232 * reciprocal_scale - "scale" a value into range [0, ep_ro)
 233 * @val: value
 234 * @ep_ro: right open interval endpoint
 235 *
 236 * Perform a "reciprocal multiplication" in order to "scale" a value into
 237 * range [0, ep_ro), where the upper interval endpoint is right-open.
 238 * This is useful, e.g. for accessing a index of an array containing
 239 * ep_ro elements, for example. Think of it as sort of modulus, only that
 240 * the result isn't that of modulo. ;) Note that if initial input is a
 241 * small value, then result will return 0.
 242 *
 243 * Return: a result based on val in interval [0, ep_ro).
 244 */
 245static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
 246{
 247        return (u32)(((u64) val * ep_ro) >> 32);
 248}
 249
 250#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)
 251void might_fault(void);
 252#else
 253static inline void might_fault(void) { }
 254#endif
 255
 256extern struct atomic_notifier_head panic_notifier_list;
 257extern long (*panic_blink)(int state);
 258__printf(1, 2)
 259void panic(const char *fmt, ...)
 260        __noreturn __cold;
 261void nmi_panic(struct pt_regs *regs, const char *msg);
 262extern void oops_enter(void);
 263extern void oops_exit(void);
 264void print_oops_end_marker(void);
 265extern int oops_may_print(void);
 266void do_exit(long error_code)
 267        __noreturn;
 268void complete_and_exit(struct completion *, long)
 269        __noreturn;
 270
 271/* Internal, do not use. */
 272int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
 273int __must_check _kstrtol(const char *s, unsigned int base, long *res);
 274
 275int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
 276int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
 277
 278/**
 279 * kstrtoul - convert a string to an unsigned long
 280 * @s: The start of the string. The string must be null-terminated, and may also
 281 *  include a single newline before its terminating null. The first character
 282 *  may also be a plus sign, but not a minus sign.
 283 * @base: The number base to use. The maximum supported base is 16. If base is
 284 *  given as 0, then the base of the string is automatically detected with the
 285 *  conventional semantics - If it begins with 0x the number will be parsed as a
 286 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 287 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 288 * @res: Where to write the result of the conversion on success.
 289 *
 290 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 291 * Used as a replacement for the obsolete simple_strtoull. Return code must
 292 * be checked.
 293*/
 294static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
 295{
 296        /*
 297         * We want to shortcut function call, but
 298         * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
 299         */
 300        if (sizeof(unsigned long) == sizeof(unsigned long long) &&
 301            __alignof__(unsigned long) == __alignof__(unsigned long long))
 302                return kstrtoull(s, base, (unsigned long long *)res);
 303        else
 304                return _kstrtoul(s, base, res);
 305}
 306
 307/**
 308 * kstrtol - convert a string to a long
 309 * @s: The start of the string. The string must be null-terminated, and may also
 310 *  include a single newline before its terminating null. The first character
 311 *  may also be a plus sign or a minus sign.
 312 * @base: The number base to use. The maximum supported base is 16. If base is
 313 *  given as 0, then the base of the string is automatically detected with the
 314 *  conventional semantics - If it begins with 0x the number will be parsed as a
 315 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 316 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 317 * @res: Where to write the result of the conversion on success.
 318 *
 319 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 320 * Used as a replacement for the obsolete simple_strtoull. Return code must
 321 * be checked.
 322 */
 323static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
 324{
 325        /*
 326         * We want to shortcut function call, but
 327         * __builtin_types_compatible_p(long, long long) = 0.
 328         */
 329        if (sizeof(long) == sizeof(long long) &&
 330            __alignof__(long) == __alignof__(long long))
 331                return kstrtoll(s, base, (long long *)res);
 332        else
 333                return _kstrtol(s, base, res);
 334}
 335
 336int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
 337int __must_check kstrtoint(const char *s, unsigned int base, int *res);
 338
 339static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
 340{
 341        return kstrtoull(s, base, res);
 342}
 343
 344static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
 345{
 346        return kstrtoll(s, base, res);
 347}
 348
 349static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
 350{
 351        return kstrtouint(s, base, res);
 352}
 353
 354static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
 355{
 356        return kstrtoint(s, base, res);
 357}
 358
 359int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
 360int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
 361int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
 362int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
 363int __must_check kstrtobool(const char *s, bool *res);
 364
 365int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
 366int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
 367int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
 368int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
 369int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
 370int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
 371int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
 372int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
 373int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
 374int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
 375int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
 376
 377static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
 378{
 379        return kstrtoull_from_user(s, count, base, res);
 380}
 381
 382static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
 383{
 384        return kstrtoll_from_user(s, count, base, res);
 385}
 386
 387static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
 388{
 389        return kstrtouint_from_user(s, count, base, res);
 390}
 391
 392static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
 393{
 394        return kstrtoint_from_user(s, count, base, res);
 395}
 396
 397/* Obsolete, do not use.  Use kstrto<foo> instead */
 398
 399extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 400extern long simple_strtol(const char *,char **,unsigned int);
 401extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 402extern long long simple_strtoll(const char *,char **,unsigned int);
 403#define strict_strtoul  kstrtoul
 404#define strict_strtol   kstrtol
 405#define strict_strtoull kstrtoull
 406#define strict_strtoll  kstrtoll
 407
 408extern int num_to_str(char *buf, int size, unsigned long long num);
 409
 410/* lib/printf utilities */
 411
 412extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
 413extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
 414extern __printf(3, 4)
 415int snprintf(char *buf, size_t size, const char *fmt, ...);
 416extern __printf(3, 0)
 417int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
 418extern __printf(3, 4)
 419int scnprintf(char *buf, size_t size, const char *fmt, ...);
 420extern __printf(3, 0)
 421int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
 422extern __printf(2, 3)
 423char *kasprintf(gfp_t gfp, const char *fmt, ...);
 424extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 425extern __printf(2, 0)
 426const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
 427
 428extern __scanf(2, 3)
 429int sscanf(const char *, const char *, ...);
 430extern __scanf(2, 0)
 431int vsscanf(const char *, const char *, va_list);
 432
 433extern int get_option(char **str, int *pint);
 434extern char *get_options(const char *str, int nints, int *ints);
 435extern unsigned long long memparse(const char *ptr, char **retptr);
 436extern bool parse_option_str(const char *str, const char *option);
 437extern char *next_arg(char *args, char **param, char **val);
 438
 439extern int core_kernel_text(unsigned long addr);
 440extern int core_kernel_data(unsigned long addr);
 441extern int __kernel_text_address(unsigned long addr);
 442extern int kernel_text_address(unsigned long addr);
 443extern int func_ptr_is_kernel_text(void *ptr);
 444
 445struct pid;
 446extern struct pid *session_of_pgrp(struct pid *pgrp);
 447
 448unsigned long int_sqrt(unsigned long);
 449
 450extern void bust_spinlocks(int yes);
 451extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 452extern int panic_timeout;
 453extern int panic_on_oops;
 454extern int panic_on_unrecovered_nmi;
 455extern int panic_on_io_nmi;
 456extern int panic_on_warn;
 457extern int sysctl_panic_on_rcu_stall;
 458extern int sysctl_panic_on_stackoverflow;
 459
 460extern bool crash_kexec_post_notifiers;
 461
 462/*
 463 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
 464 * holds a CPU number which is executing panic() currently. A value of
 465 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
 466 */
 467extern atomic_t panic_cpu;
 468#define PANIC_CPU_INVALID       -1
 469
 470/*
 471 * Only to be used by arch init code. If the user over-wrote the default
 472 * CONFIG_PANIC_TIMEOUT, honor it.
 473 */
 474static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
 475{
 476        if (panic_timeout == arch_default_timeout)
 477                panic_timeout = timeout;
 478}
 479extern const char *print_tainted(void);
 480enum lockdep_ok {
 481        LOCKDEP_STILL_OK,
 482        LOCKDEP_NOW_UNRELIABLE
 483};
 484extern void add_taint(unsigned flag, enum lockdep_ok);
 485extern int test_taint(unsigned flag);
 486extern unsigned long get_taint(void);
 487extern int root_mountflags;
 488
 489extern bool early_boot_irqs_disabled;
 490
 491/* Values used for system_state */
 492extern enum system_states {
 493        SYSTEM_BOOTING,
 494        SYSTEM_RUNNING,
 495        SYSTEM_HALT,
 496        SYSTEM_POWER_OFF,
 497        SYSTEM_RESTART,
 498} system_state;
 499
 500#define TAINT_PROPRIETARY_MODULE        0
 501#define TAINT_FORCED_MODULE             1
 502#define TAINT_UNSAFE_SMP                2
 503#define TAINT_FORCED_RMMOD              3
 504#define TAINT_MACHINE_CHECK             4
 505#define TAINT_BAD_PAGE                  5
 506#define TAINT_USER                      6
 507#define TAINT_DIE                       7
 508#define TAINT_OVERRIDDEN_ACPI_TABLE     8
 509#define TAINT_WARN                      9
 510#define TAINT_CRAP                      10
 511#define TAINT_FIRMWARE_WORKAROUND       11
 512#define TAINT_OOT_MODULE                12
 513#define TAINT_UNSIGNED_MODULE           13
 514#define TAINT_SOFTLOCKUP                14
 515#define TAINT_LIVEPATCH                 15
 516#define TAINT_16                        16
 517#define TAINT_17                        17
 518#define TAINT_18                        18
 519#define TAINT_19                        19
 520#define TAINT_20                        20
 521#define TAINT_21                        21
 522#define TAINT_22                        22
 523#define TAINT_23                        23
 524#define TAINT_24                        24
 525#define TAINT_25                        25
 526#define TAINT_26                        26
 527#define TAINT_27                        27
 528/* Reserving bits for vendor specific uses */
 529#define TAINT_HARDWARE_UNSUPPORTED      28
 530#define TAINT_TECH_PREVIEW              29
 531/* Bits 30 - 31 are reserved for Red Hat use only */
 532#define TAINT_RESERVED30                30
 533#define TAINT_RESERVED31                31
 534#define TAINT_FLAGS_COUNT               32
 535
 536struct taint_flag {
 537        char c_true;    /* character printed when tainted */
 538        char c_false;   /* character printed when not tainted */
 539        bool module;    /* also show as a per-module taint flag */
 540};
 541
 542extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
 543
 544extern const char hex_asc[];
 545#define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 546#define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 547
 548static inline char *hex_byte_pack(char *buf, u8 byte)
 549{
 550        *buf++ = hex_asc_hi(byte);
 551        *buf++ = hex_asc_lo(byte);
 552        return buf;
 553}
 554
 555extern const char hex_asc_upper[];
 556#define hex_asc_upper_lo(x)     hex_asc_upper[((x) & 0x0f)]
 557#define hex_asc_upper_hi(x)     hex_asc_upper[((x) & 0xf0) >> 4]
 558
 559static inline char *hex_byte_pack_upper(char *buf, u8 byte)
 560{
 561        *buf++ = hex_asc_upper_hi(byte);
 562        *buf++ = hex_asc_upper_lo(byte);
 563        return buf;
 564}
 565
 566static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
 567{
 568        return hex_byte_pack(buf, byte);
 569}
 570
 571extern int hex_to_bin(char ch);
 572extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
 573extern char *bin2hex(char *dst, const void *src, size_t count);
 574
 575/*
 576 * General tracing related utility functions - trace_printk(),
 577 * tracing_on/tracing_off and tracing_start()/tracing_stop
 578 *
 579 * Use tracing_on/tracing_off when you want to quickly turn on or off
 580 * tracing. It simply enables or disables the recording of the trace events.
 581 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
 582 * file, which gives a means for the kernel and userspace to interact.
 583 * Place a tracing_off() in the kernel where you want tracing to end.
 584 * From user space, examine the trace, and then echo 1 > tracing_on
 585 * to continue tracing.
 586 *
 587 * tracing_stop/tracing_start has slightly more overhead. It is used
 588 * by things like suspend to ram where disabling the recording of the
 589 * trace is not enough, but tracing must actually stop because things
 590 * like calling smp_processor_id() may crash the system.
 591 *
 592 * Most likely, you want to use tracing_on/tracing_off.
 593 */
 594#ifdef CONFIG_RING_BUFFER
 595/* trace_off_permanent stops recording with no way to bring it back */
 596void tracing_off_permanent(void);
 597#else
 598static inline void tracing_off_permanent(void) { }
 599#endif
 600
 601enum ftrace_dump_mode {
 602        DUMP_NONE,
 603        DUMP_ALL,
 604        DUMP_ORIG,
 605};
 606
 607#ifdef CONFIG_TRACING
 608void tracing_on(void);
 609void tracing_off(void);
 610int tracing_is_on(void);
 611void tracing_snapshot(void);
 612void tracing_snapshot_alloc(void);
 613
 614extern void tracing_start(void);
 615extern void tracing_stop(void);
 616
 617static inline __printf(1, 2)
 618void ____trace_printk_check_format(const char *fmt, ...)
 619{
 620}
 621#define __trace_printk_check_format(fmt, args...)                       \
 622do {                                                                    \
 623        if (0)                                                          \
 624                ____trace_printk_check_format(fmt, ##args);             \
 625} while (0)
 626
 627/**
 628 * trace_printk - printf formatting in the ftrace buffer
 629 * @fmt: the printf format for printing
 630 *
 631 * Note: __trace_printk is an internal function for trace_printk and
 632 *       the @ip is passed in via the trace_printk macro.
 633 *
 634 * This function allows a kernel developer to debug fast path sections
 635 * that printk is not appropriate for. By scattering in various
 636 * printk like tracing in the code, a developer can quickly see
 637 * where problems are occurring.
 638 *
 639 * This is intended as a debugging tool for the developer only.
 640 * Please refrain from leaving trace_printks scattered around in
 641 * your code. (Extra memory is used for special buffers that are
 642 * allocated when trace_printk() is used)
 643 *
 644 * A little optization trick is done here. If there's only one
 645 * argument, there's no need to scan the string for printf formats.
 646 * The trace_puts() will suffice. But how can we take advantage of
 647 * using trace_puts() when trace_printk() has only one argument?
 648 * By stringifying the args and checking the size we can tell
 649 * whether or not there are args. __stringify((__VA_ARGS__)) will
 650 * turn into "()\0" with a size of 3 when there are no args, anything
 651 * else will be bigger. All we need to do is define a string to this,
 652 * and then take its size and compare to 3. If it's bigger, use
 653 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
 654 * let gcc optimize the rest.
 655 */
 656
 657#define trace_printk(fmt, ...)                          \
 658do {                                                    \
 659        char _______STR[] = __stringify((__VA_ARGS__)); \
 660        if (sizeof(_______STR) > 3)                     \
 661                do_trace_printk(fmt, ##__VA_ARGS__);    \
 662        else                                            \
 663                trace_puts(fmt);                        \
 664} while (0)
 665
 666#define do_trace_printk(fmt, args...)                                   \
 667do {                                                                    \
 668        static const char *trace_printk_fmt                             \
 669                __attribute__((section("__trace_printk_fmt"))) =        \
 670                __builtin_constant_p(fmt) ? fmt : NULL;                 \
 671                                                                        \
 672        __trace_printk_check_format(fmt, ##args);                       \
 673                                                                        \
 674        if (__builtin_constant_p(fmt))                                  \
 675                __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);   \
 676        else                                                            \
 677                __trace_printk(_THIS_IP_, fmt, ##args);                 \
 678} while (0)
 679
 680extern __printf(2, 3)
 681int __trace_bprintk(unsigned long ip, const char *fmt, ...);
 682
 683extern __printf(2, 3)
 684int __trace_printk(unsigned long ip, const char *fmt, ...);
 685
 686extern int __trace_bputs(unsigned long ip, const char *str);
 687extern int __trace_puts(unsigned long ip, const char *str, int size);
 688
 689/**
 690 * trace_puts - write a string into the ftrace buffer
 691 * @str: the string to record
 692 *
 693 * Note: __trace_bputs is an internal function for trace_puts and
 694 *       the @ip is passed in via the trace_puts macro.
 695 *
 696 * This is similar to trace_printk() but is made for those really fast
 697 * paths that a developer wants the least amount of "Heisenbug" affects,
 698 * where the processing of the print format is still too much.
 699 *
 700 * This function allows a kernel developer to debug fast path sections
 701 * that printk is not appropriate for. By scattering in various
 702 * printk like tracing in the code, a developer can quickly see
 703 * where problems are occurring.
 704 *
 705 * This is intended as a debugging tool for the developer only.
 706 * Please refrain from leaving trace_puts scattered around in
 707 * your code. (Extra memory is used for special buffers that are
 708 * allocated when trace_puts() is used)
 709 *
 710 * Returns: 0 if nothing was written, positive # if string was.
 711 *  (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
 712 */
 713
 714#define trace_puts(str) ({                                              \
 715        static const char *trace_printk_fmt                             \
 716                __attribute__((section("__trace_printk_fmt"))) =        \
 717                __builtin_constant_p(str) ? str : NULL;                 \
 718                                                                        \
 719        if (__builtin_constant_p(str))                                  \
 720                __trace_bputs(_THIS_IP_, trace_printk_fmt);             \
 721        else                                                            \
 722                __trace_puts(_THIS_IP_, str, strlen(str));              \
 723})
 724
 725extern void trace_dump_stack(int skip);
 726
 727/*
 728 * The double __builtin_constant_p is because gcc will give us an error
 729 * if we try to allocate the static variable to fmt if it is not a
 730 * constant. Even with the outer if statement.
 731 */
 732#define ftrace_vprintk(fmt, vargs)                                      \
 733do {                                                                    \
 734        if (__builtin_constant_p(fmt)) {                                \
 735                static const char *trace_printk_fmt                     \
 736                  __attribute__((section("__trace_printk_fmt"))) =      \
 737                        __builtin_constant_p(fmt) ? fmt : NULL;         \
 738                                                                        \
 739                __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);  \
 740        } else                                                          \
 741                __ftrace_vprintk(_THIS_IP_, fmt, vargs);                \
 742} while (0)
 743
 744extern int
 745__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
 746
 747extern int
 748__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 749
 750extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
 751#else
 752static inline void tracing_start(void) { }
 753static inline void tracing_stop(void) { }
 754static inline void trace_dump_stack(void) { }
 755
 756static inline void tracing_on(void) { }
 757static inline void tracing_off(void) { }
 758static inline int tracing_is_on(void) { return 0; }
 759static inline void tracing_snapshot(void) { }
 760static inline void tracing_snapshot_alloc(void) { }
 761
 762static inline __printf(1, 2)
 763int trace_printk(const char *fmt, ...)
 764{
 765        return 0;
 766}
 767static inline int
 768ftrace_vprintk(const char *fmt, va_list ap)
 769{
 770        return 0;
 771}
 772static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 773#endif /* CONFIG_TRACING */
 774
 775/*
 776 * min()/max()/clamp() macros that also do
 777 * strict type-checking.. See the
 778 * "unnecessary" pointer comparison.
 779 */
 780#define min(x, y) ({                            \
 781        typeof(x) _min1 = (x);                  \
 782        typeof(y) _min2 = (y);                  \
 783        (void) (&_min1 == &_min2);              \
 784        _min1 < _min2 ? _min1 : _min2; })
 785
 786#define max(x, y) ({                            \
 787        typeof(x) _max1 = (x);                  \
 788        typeof(y) _max2 = (y);                  \
 789        (void) (&_max1 == &_max2);              \
 790        _max1 > _max2 ? _max1 : _max2; })
 791
 792#define min3(x, y, z) ({                        \
 793        typeof(x) _min1 = (x);                  \
 794        typeof(y) _min2 = (y);                  \
 795        typeof(z) _min3 = (z);                  \
 796        (void) (&_min1 == &_min2);              \
 797        (void) (&_min1 == &_min3);              \
 798        _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
 799                (_min2 < _min3 ? _min2 : _min3); })
 800
 801#define max3(x, y, z) ({                        \
 802        typeof(x) _max1 = (x);                  \
 803        typeof(y) _max2 = (y);                  \
 804        typeof(z) _max3 = (z);                  \
 805        (void) (&_max1 == &_max2);              \
 806        (void) (&_max1 == &_max3);              \
 807        _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
 808                (_max2 > _max3 ? _max2 : _max3); })
 809
 810/**
 811 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
 812 * @x: value1
 813 * @y: value2
 814 */
 815#define min_not_zero(x, y) ({                   \
 816        typeof(x) __x = (x);                    \
 817        typeof(y) __y = (y);                    \
 818        __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
 819
 820/**
 821 * clamp - return a value clamped to a given range with strict typechecking
 822 * @val: current value
 823 * @min: minimum allowable value
 824 * @max: maximum allowable value
 825 *
 826 * This macro does strict typechecking of min/max to make sure they are of the
 827 * same type as val.  See the unnecessary pointer comparisons.
 828 */
 829#define clamp(val, min, max) ({                 \
 830        typeof(val) __val = (val);              \
 831        typeof(min) __min = (min);              \
 832        typeof(max) __max = (max);              \
 833        (void) (&__val == &__min);              \
 834        (void) (&__val == &__max);              \
 835        __val = __val < __min ? __min: __val;   \
 836        __val > __max ? __max: __val; })
 837
 838/*
 839 * ..and if you can't take the strict
 840 * types, you can specify one yourself.
 841 *
 842 * Or not use min/max/clamp at all, of course.
 843 */
 844#define min_t(type, x, y) ({                    \
 845        type __min1 = (x);                      \
 846        type __min2 = (y);                      \
 847        __min1 < __min2 ? __min1: __min2; })
 848
 849#define max_t(type, x, y) ({                    \
 850        type __max1 = (x);                      \
 851        type __max2 = (y);                      \
 852        __max1 > __max2 ? __max1: __max2; })
 853
 854/**
 855 * clamp_t - return a value clamped to a given range using a given type
 856 * @type: the type of variable to use
 857 * @val: current value
 858 * @min: minimum allowable value
 859 * @max: maximum allowable value
 860 *
 861 * This macro does no typechecking and uses temporary variables of type
 862 * 'type' to make all the comparisons.
 863 */
 864#define clamp_t(type, val, min, max) ({         \
 865        type __val = (val);                     \
 866        type __min = (min);                     \
 867        type __max = (max);                     \
 868        __val = __val < __min ? __min: __val;   \
 869        __val > __max ? __max: __val; })
 870
 871/**
 872 * clamp_val - return a value clamped to a given range using val's type
 873 * @val: current value
 874 * @min: minimum allowable value
 875 * @max: maximum allowable value
 876 *
 877 * This macro does no typechecking and uses temporary variables of whatever
 878 * type the input argument 'val' is.  This is useful when val is an unsigned
 879 * type and min and max are literals that will otherwise be assigned a signed
 880 * integer type.
 881 */
 882#define clamp_val(val, min, max) ({             \
 883        typeof(val) __val = (val);              \
 884        typeof(val) __min = (min);              \
 885        typeof(val) __max = (max);              \
 886        __val = __val < __min ? __min: __val;   \
 887        __val > __max ? __max: __val; })
 888
 889
 890/*
 891 * swap - swap value of @a and @b
 892 */
 893#define swap(a, b) \
 894        do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 895
 896/**
 897 * container_of - cast a member of a structure out to the containing structure
 898 * @ptr:        the pointer to the member.
 899 * @type:       the type of the container struct this is embedded in.
 900 * @member:     the name of the member within the struct.
 901 *
 902 */
 903#define container_of(ptr, type, member) ({                      \
 904        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 905        (type *)( (char *)__mptr - offsetof(type,member) );})
 906
 907/* Trap pasters of __FUNCTION__ at compile-time */
 908#define __FUNCTION__ (__func__)
 909
 910/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 911#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 912# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 913#endif
 914
 915struct module;
 916
 917void mark_hardware_unsupported(const char *msg);
 918void mark_hardware_deprecated(const char *msg);
 919void mark_tech_preview(const char *msg, struct module *mod);
 920
 921#else
 922#ifndef pr_fmt
 923#define pr_fmt(fmt) fmt
 924#endif
 925#endif
 926