include/linux/kernel.h

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