include/linux/kernel.h

   1 #ifndef _LINUX_KERNEL_H
   2 #define _LINUX_KERNEL_H
   3
   4 /*
   5  * 'kernel.h' contains some often-used function prototypes etc
   6  */
   7 #define __ALIGN_KERNEL(x, a)            __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
   8 #define __ALIGN_KERNEL_MASK(x, mask)    (((x) + (mask)) & ~(mask))
   9
  10 #ifdef __KERNEL__
  11
  12 #include <stdarg.h>
  13 #include <linux/linkage.h>
  14 #include <linux/stddef.h>
  15 #include <linux/types.h>
  16 #include <linux/compiler.h>
  17 #include <linux/bitops.h>
  18 #include <linux/log2.h>
  19 #include <linux/typecheck.h>
  20 #include <linux/dynamic_debug.h>
  21 #include <asm/byteorder.h>
  22 #include <asm/bug.h>
  23
  24 extern const char linux_banner[];
  25 extern const char linux_proc_banner[];
  26
  27 #define USHRT_MAX       ((u16)(~0U))
  28 #define SHRT_MAX        ((s16)(USHRT_MAX>>1))
  29 #define SHRT_MIN        ((s16)(-SHRT_MAX - 1))
  30 #define INT_MAX         ((int)(~0U>>1))
  31 #define INT_MIN         (-INT_MAX - 1)
  32 #define UINT_MAX        (~0U)
  33 #define LONG_MAX        ((long)(~0UL>>1))
  34 #define LONG_MIN        (-LONG_MAX - 1)
  35 #define ULONG_MAX       (~0UL)
  36 #define LLONG_MAX       ((long long)(~0ULL>>1))
  37 #define LLONG_MIN       (-LLONG_MAX - 1)
  38 #define ULLONG_MAX      (~0ULL)
  39
  40 #define STACK_MAGIC     0xdeadbeef
  41
  42 #define ALIGN(x, a)             __ALIGN_KERNEL((x), (a))
  43 #define __ALIGN_MASK(x, mask)   __ALIGN_KERNEL_MASK((x), (mask))
  44 #define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  45 #define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  46
  47 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  48
  49 /*
  50  * This looks more complex than it should be. But we need to
  51  * get the type for the ~ right in round_down (it needs to be
  52  * as wide as the result!), and we want to evaluate the macro
  53  * arguments just once each.
  54  */
  55 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
  56 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
  57 #define round_down(x, y) ((x) & ~__round_mask(x, y))
  58
  59 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  60 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  61 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  62 #define DIV_ROUND_CLOSEST(x, divisor)(                  \
  63 {                                                       \
  64         typeof(divisor) __divisor = divisor;            \
  65         (((x) + ((__divisor) / 2)) / (__divisor));      \
  66 }                                                       \
  67 )
  68
  69 #define _RET_IP_                (unsigned long)__builtin_return_address(0)
  70 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
  71
  72 #ifdef CONFIG_LBDAF
  73 # include <asm/div64.h>
  74 # define sector_div(a, b) do_div(a, b)
  75 #else
  76 # define sector_div(n, b)( \
  77 { \
  78         int _res; \
  79         _res = (n) % (b); \
  80         (n) /= (b); \
  81         _res; \
  82 } \
  83 )
  84 #endif
  85
  86 /**
  87  * upper_32_bits - return bits 32-63 of a number
  88  * @n: the number we're accessing
  89  *
  90  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  91  * the "right shift count >= width of type" warning when that quantity is
  92  * 32-bits.
  93  */
  94 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  95
  96 /**
  97  * lower_32_bits - return bits 0-31 of a number
  98  * @n: the number we're accessing
  99  */
 100 #define lower_32_bits(n) ((u32)(n))
 101
 102 #define KERN_EMERG      "<0>"   /* system is unusable                   */
 103 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
 104 #define KERN_CRIT       "<2>"   /* critical conditions                  */
 105 #define KERN_ERR        "<3>"   /* error conditions                     */
 106 #define KERN_WARNING    "<4>"   /* warning conditions                   */
 107 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
 108 #define KERN_INFO       "<6>"   /* informational                        */
 109 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
 110
 111 /* Use the default kernel loglevel */
 112 #define KERN_DEFAULT    "<d>"
 113 /*
 114  * Annotation for a "continued" line of log printout (only done after a
 115  * line that had no enclosing \n). Only to be used by core/arch code
 116  * during early bootup (a continued line is not SMP-safe otherwise).
 117  */
 118 #define KERN_CONT       "<c>"
 119
 120 extern int console_printk[];
 121
 122 #define console_loglevel (console_printk[0])
 123 #define default_message_loglevel (console_printk[1])
 124 #define minimum_console_loglevel (console_printk[2])
 125 #define default_console_loglevel (console_printk[3])
 126
 127 struct completion;
 128 struct pt_regs;
 129 struct user;
 130
 131 #ifdef CONFIG_PREEMPT_VOLUNTARY
 132 extern int _cond_resched(void);
 133 # define might_resched() _cond_resched()
 134 #else
 135 # define might_resched() do { } while (0)
 136 #endif
 137
 138 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 139   void __might_sleep(const char *file, int line, int preempt_offset);
 140 /**
 141  * might_sleep - annotation for functions that can sleep
 142  *
 143  * this macro will print a stack trace if it is executed in an atomic
 144  * context (spinlock, irq-handler, ...).
 145  *
 146  * This is a useful debugging help to be able to catch problems early and not
 147  * be bitten later when the calling function happens to sleep when it is not
 148  * supposed to.
 149  */
 150 # define might_sleep() \
 151         do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 152 #else
 153   static inline void __might_sleep(const char *file, int line,
 154                                    int preempt_offset) { }
 155 # define might_sleep() do { might_resched(); } while (0)
 156 #endif
 157
 158 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 159
 160 #define abs(x) ({                               \
 161                 long __x = (x);                 \
 162                 (__x < 0) ? -__x : __x;         \
 163         })
 164
 165 #ifdef CONFIG_PROVE_LOCKING
 166 void might_fault(void);
 167 #else
 168 static inline void might_fault(void)
 169 {
 170         might_sleep();
 171 }
 172 #endif
 173
 174 extern struct atomic_notifier_head panic_notifier_list;
 175 extern long (*panic_blink)(long time);
 176 NORET_TYPE void panic(const char * fmt, ...)
 177         __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 178 extern void oops_enter(void);
 179 extern void oops_exit(void);
 180 extern int oops_may_print(void);
 181 NORET_TYPE void do_exit(long error_code)
 182         ATTRIB_NORET;
 183 NORET_TYPE void complete_and_exit(struct completion *, long)
 184         ATTRIB_NORET;
 185 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 186 extern long simple_strtol(const char *,char **,unsigned int);
 187 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 188 extern long long simple_strtoll(const char *,char **,unsigned int);
 189 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 190 extern int strict_strtol(const char *, unsigned int, long *);
 191 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 192 extern int strict_strtoll(const char *, unsigned int, long long *);
 193 extern int sprintf(char * buf, const char * fmt, ...)
 194         __attribute__ ((format (printf, 2, 3)));
 195 extern int vsprintf(char *buf, const char *, va_list)
 196         __attribute__ ((format (printf, 2, 0)));
 197 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 198         __attribute__ ((format (printf, 3, 4)));
 199 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 200         __attribute__ ((format (printf, 3, 0)));
 201 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 202         __attribute__ ((format (printf, 3, 4)));
 203 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 204         __attribute__ ((format (printf, 3, 0)));
 205 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 206         __attribute__ ((format (printf, 2, 3)));
 207 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 208
 209 extern int sscanf(const char *, const char *, ...)
 210         __attribute__ ((format (scanf, 2, 3)));
 211 extern int vsscanf(const char *, const char *, va_list)
 212         __attribute__ ((format (scanf, 2, 0)));
 213
 214 extern int get_option(char **str, int *pint);
 215 extern char *get_options(const char *str, int nints, int *ints);
 216 extern unsigned long long memparse(const char *ptr, char **retptr);
 217
 218 extern int core_kernel_text(unsigned long addr);
 219 extern int __kernel_text_address(unsigned long addr);
 220 extern int kernel_text_address(unsigned long addr);
 221 extern int func_ptr_is_kernel_text(void *ptr);
 222
 223 struct pid;
 224 extern struct pid *session_of_pgrp(struct pid *pgrp);
 225
 226 /*
 227  * FW_BUG
 228  * Add this to a message where you are sure the firmware is buggy or behaves
 229  * really stupid or out of spec. Be aware that the responsible BIOS developer
 230  * should be able to fix this issue or at least get a concrete idea of the
 231  * problem by reading your message without the need of looking at the kernel
 232  * code.
 233  *
 234  * Use it for definite and high priority BIOS bugs.
 235  *
 236  * FW_WARN
 237  * Use it for not that clear (e.g. could the kernel messed up things already?)
 238  * and medium priority BIOS bugs.
 239  *
 240  * FW_INFO
 241  * Use this one if you want to tell the user or vendor about something
 242  * suspicious, but generally harmless related to the firmware.
 243  *
 244  * Use it for information or very low priority BIOS bugs.
 245  */
 246 #define FW_BUG          "[Firmware Bug]: "
 247 #define FW_WARN         "[Firmware Warn]: "
 248 #define FW_INFO         "[Firmware Info]: "
 249
 250 #ifdef CONFIG_PRINTK
 251 asmlinkage int vprintk(const char *fmt, va_list args)
 252         __attribute__ ((format (printf, 1, 0)));
 253 asmlinkage int printk(const char * fmt, ...)
 254         __attribute__ ((format (printf, 1, 2))) __cold;
 255
 256 extern int __printk_ratelimit(const char *func);
 257 #define printk_ratelimit() __printk_ratelimit(__func__)
 258 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 259                                    unsigned int interval_msec);
 260
 261 extern int printk_delay_msec;
 262
 263 /*
 264  * Print a one-time message (analogous to WARN_ONCE() et al):
 265  */
 266 #define printk_once(x...) ({                    \
 267         static bool __print_once;               \
 268                                                 \
 269         if (!__print_once) {                    \
 270                 __print_once = true;            \
 271                 printk(x);                      \
 272         }                                       \
 273 })
 274
 275 void log_buf_kexec_setup(void);
 276 #else
 277 static inline int vprintk(const char *s, va_list args)
 278         __attribute__ ((format (printf, 1, 0)));
 279 static inline int vprintk(const char *s, va_list args) { return 0; }
 280 static inline int printk(const char *s, ...)
 281         __attribute__ ((format (printf, 1, 2)));
 282 static inline int __cold printk(const char *s, ...) { return 0; }
 283 static inline int printk_ratelimit(void) { return 0; }
 284 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 285                                           unsigned int interval_msec)   \
 286                 { return false; }
 287
 288 /* No effect, but we still get type checking even in the !PRINTK case: */
 289 #define printk_once(x...) printk(x)
 290
 291 static inline void log_buf_kexec_setup(void)
 292 {
 293 }
 294 #endif
 295
 296 extern int printk_needs_cpu(int cpu);
 297 extern void printk_tick(void);
 298
 299 extern void asmlinkage __attribute__((format(printf, 1, 2)))
 300         early_printk(const char *fmt, ...);
 301
 302 unsigned long int_sqrt(unsigned long);
 303
 304 static inline void console_silent(void)
 305 {
 306         console_loglevel = 0;
 307 }
 308
 309 static inline void console_verbose(void)
 310 {
 311         if (console_loglevel)
 312                 console_loglevel = 15;
 313 }
 314
 315 extern void bust_spinlocks(int yes);
 316 extern void wake_up_klogd(void);
 317 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 318 extern int panic_timeout;
 319 extern int panic_on_oops;
 320 extern int panic_on_unrecovered_nmi;
 321 extern int panic_on_io_nmi;
 322 extern const char *print_tainted(void);
 323 extern void add_taint(unsigned flag);
 324 extern int test_taint(unsigned flag);
 325 extern unsigned long get_taint(void);
 326 extern int root_mountflags;
 327
 328 /* Values used for system_state */
 329 extern enum system_states {
 330         SYSTEM_BOOTING,
 331         SYSTEM_RUNNING,
 332         SYSTEM_HALT,
 333         SYSTEM_POWER_OFF,
 334         SYSTEM_RESTART,
 335         SYSTEM_SUSPEND_DISK,
 336 } system_state;
 337
 338 #define TAINT_PROPRIETARY_MODULE        0
 339 #define TAINT_FORCED_MODULE             1
 340 #define TAINT_UNSAFE_SMP                2
 341 #define TAINT_FORCED_RMMOD              3
 342 #define TAINT_MACHINE_CHECK             4
 343 #define TAINT_BAD_PAGE                  5
 344 #define TAINT_USER                      6
 345 #define TAINT_DIE                       7
 346 #define TAINT_OVERRIDDEN_ACPI_TABLE     8
 347 #define TAINT_WARN                      9
 348 #define TAINT_CRAP                      10
 349 #define TAINT_FIRMWARE_WORKAROUND       11
 350
 351 extern void dump_stack(void) __cold;
 352
 353 enum {
 354         DUMP_PREFIX_NONE,
 355         DUMP_PREFIX_ADDRESS,
 356         DUMP_PREFIX_OFFSET
 357 };
 358 extern void hex_dump_to_buffer(const void *buf, size_t len,
 359                                 int rowsize, int groupsize,
 360                                 char *linebuf, size_t linebuflen, bool ascii);
 361 extern void print_hex_dump(const char *level, const char *prefix_str,
 362                                 int prefix_type, int rowsize, int groupsize,
 363                                 const void *buf, size_t len, bool ascii);
 364 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 365                         const void *buf, size_t len);
 366
 367 extern const char hex_asc[];
 368 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 369 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 370
 371 static inline char *pack_hex_byte(char *buf, u8 byte)
 372 {
 373         *buf++ = hex_asc_hi(byte);
 374         *buf++ = hex_asc_lo(byte);
 375         return buf;
 376 }
 377
 378 extern int hex_to_bin(char ch);
 379
 380 #ifndef pr_fmt
 381 #define pr_fmt(fmt) fmt
 382 #endif
 383
 384 #define pr_emerg(fmt, ...) \
 385         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 386 #define pr_alert(fmt, ...) \
 387         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 388 #define pr_crit(fmt, ...) \
 389         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 390 #define pr_err(fmt, ...) \
 391         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 392 #define pr_warning(fmt, ...) \
 393         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 394 #define pr_warn pr_warning
 395 #define pr_notice(fmt, ...) \
 396         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 397 #define pr_info(fmt, ...) \
 398         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 399 #define pr_cont(fmt, ...) \
 400         printk(KERN_CONT fmt, ##__VA_ARGS__)
 401
 402 /* pr_devel() should produce zero code unless DEBUG is defined */
 403 #ifdef DEBUG
 404 #define pr_devel(fmt, ...) \
 405         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 406 #else
 407 #define pr_devel(fmt, ...) \
 408         ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
 409 #endif
 410
 411 /* If you are writing a driver, please use dev_dbg instead */
 412 #if defined(DEBUG)
 413 #define pr_debug(fmt, ...) \
 414         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 415 #elif defined(CONFIG_DYNAMIC_DEBUG)
 416 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 417 #define pr_debug(fmt, ...) \
 418         dynamic_pr_debug(fmt, ##__VA_ARGS__)
 419 #else
 420 #define pr_debug(fmt, ...) \
 421         ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
 422 #endif
 423
 424 /*
 425  * ratelimited messages with local ratelimit_state,
 426  * no local ratelimit_state used in the !PRINTK case
 427  */
 428 #ifdef CONFIG_PRINTK
 429 #define printk_ratelimited(fmt, ...)  ({                                \
 430         static DEFINE_RATELIMIT_STATE(_rs,                              \
 431                                       DEFAULT_RATELIMIT_INTERVAL,       \
 432                                       DEFAULT_RATELIMIT_BURST);         \
 433                                                                         \
 434         if (__ratelimit(&_rs))                                          \
 435                 printk(fmt, ##__VA_ARGS__);                             \
 436 })
 437 #else
 438 /* No effect, but we still get type checking even in the !PRINTK case: */
 439 #define printk_ratelimited printk
 440 #endif
 441
 442 #define pr_emerg_ratelimited(fmt, ...) \
 443         printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 444 #define pr_alert_ratelimited(fmt, ...) \
 445         printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 446 #define pr_crit_ratelimited(fmt, ...) \
 447         printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 448 #define pr_err_ratelimited(fmt, ...) \
 449         printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 450 #define pr_warning_ratelimited(fmt, ...) \
 451         printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 452 #define pr_warn_ratelimited pr_warning_ratelimited
 453 #define pr_notice_ratelimited(fmt, ...) \
 454         printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 455 #define pr_info_ratelimited(fmt, ...) \
 456         printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 457 /* no pr_cont_ratelimited, don't do that... */
 458 /* If you are writing a driver, please use dev_dbg instead */
 459 #if defined(DEBUG)
 460 #define pr_debug_ratelimited(fmt, ...) \
 461         printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 462 #else
 463 #define pr_debug_ratelimited(fmt, ...) \
 464         ({ if (0) printk_ratelimited(KERN_DEBUG pr_fmt(fmt), \
 465                                      ##__VA_ARGS__); 0; })
 466 #endif
 467
 468 /*
 469  * General tracing related utility functions - trace_printk(),
 470  * tracing_on/tracing_off and tracing_start()/tracing_stop
 471  *
 472  * Use tracing_on/tracing_off when you want to quickly turn on or off
 473  * tracing. It simply enables or disables the recording of the trace events.
 474  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
 475  * file, which gives a means for the kernel and userspace to interact.
 476  * Place a tracing_off() in the kernel where you want tracing to end.
 477  * From user space, examine the trace, and then echo 1 > tracing_on
 478  * to continue tracing.
 479  *
 480  * tracing_stop/tracing_start has slightly more overhead. It is used
 481  * by things like suspend to ram where disabling the recording of the
 482  * trace is not enough, but tracing must actually stop because things
 483  * like calling smp_processor_id() may crash the system.
 484  *
 485  * Most likely, you want to use tracing_on/tracing_off.
 486  */
 487 #ifdef CONFIG_RING_BUFFER
 488 void tracing_on(void);
 489 void tracing_off(void);
 490 /* trace_off_permanent stops recording with no way to bring it back */
 491 void tracing_off_permanent(void);
 492 int tracing_is_on(void);
 493 #else
 494 static inline void tracing_on(void) { }
 495 static inline void tracing_off(void) { }
 496 static inline void tracing_off_permanent(void) { }
 497 static inline int tracing_is_on(void) { return 0; }
 498 #endif
 499
 500 enum ftrace_dump_mode {
 501         DUMP_NONE,
 502         DUMP_ALL,
 503         DUMP_ORIG,
 504 };
 505
 506 #ifdef CONFIG_TRACING
 507 extern void tracing_start(void);
 508 extern void tracing_stop(void);
 509 extern void ftrace_off_permanent(void);
 510
 511 extern void
 512 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
 513
 514 static inline void __attribute__ ((format (printf, 1, 2)))
 515 ____trace_printk_check_format(const char *fmt, ...)
 516 {
 517 }
 518 #define __trace_printk_check_format(fmt, args...)                       \
 519 do {                                                                    \
 520         if (0)                                                          \
 521                 ____trace_printk_check_format(fmt, ##args);             \
 522 } while (0)
 523
 524 /**
 525  * trace_printk - printf formatting in the ftrace buffer
 526  * @fmt: the printf format for printing
 527  *
 528  * Note: __trace_printk is an internal function for trace_printk and
 529  *       the @ip is passed in via the trace_printk macro.
 530  *
 531  * This function allows a kernel developer to debug fast path sections
 532  * that printk is not appropriate for. By scattering in various
 533  * printk like tracing in the code, a developer can quickly see
 534  * where problems are occurring.
 535  *
 536  * This is intended as a debugging tool for the developer only.
 537  * Please refrain from leaving trace_printks scattered around in
 538  * your code.
 539  */
 540
 541 #define trace_printk(fmt, args...)                                      \
 542 do {                                                                    \
 543         __trace_printk_check_format(fmt, ##args);                       \
 544         if (__builtin_constant_p(fmt)) {                                \
 545                 static const char *trace_printk_fmt                     \
 546                   __attribute__((section("__trace_printk_fmt"))) =      \
 547                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 548                                                                         \
 549                 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);   \
 550         } else                                                          \
 551                 __trace_printk(_THIS_IP_, fmt, ##args);         \
 552 } while (0)
 553
 554 extern int
 555 __trace_bprintk(unsigned long ip, const char *fmt, ...)
 556         __attribute__ ((format (printf, 2, 3)));
 557
 558 extern int
 559 __trace_printk(unsigned long ip, const char *fmt, ...)
 560         __attribute__ ((format (printf, 2, 3)));
 561
 562 extern void trace_dump_stack(void);
 563
 564 /*
 565  * The double __builtin_constant_p is because gcc will give us an error
 566  * if we try to allocate the static variable to fmt if it is not a
 567  * constant. Even with the outer if statement.
 568  */
 569 #define ftrace_vprintk(fmt, vargs)                                      \
 570 do {                                                                    \
 571         if (__builtin_constant_p(fmt)) {                                \
 572                 static const char *trace_printk_fmt                     \
 573                   __attribute__((section("__trace_printk_fmt"))) =      \
 574                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 575                                                                         \
 576                 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);  \
 577         } else                                                          \
 578                 __ftrace_vprintk(_THIS_IP_, fmt, vargs);                \
 579 } while (0)
 580
 581 extern int
 582 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
 583
 584 extern int
 585 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 586
 587 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
 588 #else
 589 static inline void
 590 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 591 static inline int
 592 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
 593
 594 static inline void tracing_start(void) { }
 595 static inline void tracing_stop(void) { }
 596 static inline void ftrace_off_permanent(void) { }
 597 static inline void trace_dump_stack(void) { }
 598 static inline int
 599 trace_printk(const char *fmt, ...)
 600 {
 601         return 0;
 602 }
 603 static inline int
 604 ftrace_vprintk(const char *fmt, va_list ap)
 605 {
 606         return 0;
 607 }
 608 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 609 #endif /* CONFIG_TRACING */
 610
 611 /*
 612  *      Display an IP address in readable format.
 613  */
 614
 615 #define NIPQUAD(addr) \
 616         ((unsigned char *)&addr)[0], \
 617         ((unsigned char *)&addr)[1], \
 618         ((unsigned char *)&addr)[2], \
 619         ((unsigned char *)&addr)[3]
 620 #define NIPQUAD_FMT "%u.%u.%u.%u"
 621
 622 /*
 623  * min()/max()/clamp() macros that also do
 624  * strict type-checking.. See the
 625  * "unnecessary" pointer comparison.
 626  */
 627 #define min(x, y) ({                            \
 628         typeof(x) _min1 = (x);                  \
 629         typeof(y) _min2 = (y);                  \
 630         (void) (&_min1 == &_min2);              \
 631         _min1 < _min2 ? _min1 : _min2; })
 632
 633 #define max(x, y) ({                            \
 634         typeof(x) _max1 = (x);                  \
 635         typeof(y) _max2 = (y);                  \
 636         (void) (&_max1 == &_max2);              \
 637         _max1 > _max2 ? _max1 : _max2; })
 638
 639 /**
 640  * clamp - return a value clamped to a given range with strict typechecking
 641  * @val: current value
 642  * @min: minimum allowable value
 643  * @max: maximum allowable value
 644  *
 645  * This macro does strict typechecking of min/max to make sure they are of the
 646  * same type as val.  See the unnecessary pointer comparisons.
 647  */
 648 #define clamp(val, min, max) ({                 \
 649         typeof(val) __val = (val);              \
 650         typeof(min) __min = (min);              \
 651         typeof(max) __max = (max);              \
 652         (void) (&__val == &__min);              \
 653         (void) (&__val == &__max);              \
 654         __val = __val < __min ? __min: __val;   \
 655         __val > __max ? __max: __val; })
 656
 657 /*
 658  * ..and if you can't take the strict
 659  * types, you can specify one yourself.
 660  *
 661  * Or not use min/max/clamp at all, of course.
 662  */
 663 #define min_t(type, x, y) ({                    \
 664         type __min1 = (x);                      \
 665         type __min2 = (y);                      \
 666         __min1 < __min2 ? __min1: __min2; })
 667
 668 #define max_t(type, x, y) ({                    \
 669         type __max1 = (x);                      \
 670         type __max2 = (y);                      \
 671         __max1 > __max2 ? __max1: __max2; })
 672
 673 /**
 674  * clamp_t - return a value clamped to a given range using a given type
 675  * @type: the type of variable to use
 676  * @val: current value
 677  * @min: minimum allowable value
 678  * @max: maximum allowable value
 679  *
 680  * This macro does no typechecking and uses temporary variables of type
 681  * 'type' to make all the comparisons.
 682  */
 683 #define clamp_t(type, val, min, max) ({         \
 684         type __val = (val);                     \
 685         type __min = (min);                     \
 686         type __max = (max);                     \
 687         __val = __val < __min ? __min: __val;   \
 688         __val > __max ? __max: __val; })
 689
 690 /**
 691  * clamp_val - return a value clamped to a given range using val's type
 692  * @val: current value
 693  * @min: minimum allowable value
 694  * @max: maximum allowable value
 695  *
 696  * This macro does no typechecking and uses temporary variables of whatever
 697  * type the input argument 'val' is.  This is useful when val is an unsigned
 698  * type and min and max are literals that will otherwise be assigned a signed
 699  * integer type.
 700  */
 701 #define clamp_val(val, min, max) ({             \
 702         typeof(val) __val = (val);              \
 703         typeof(val) __min = (min);              \
 704         typeof(val) __max = (max);              \
 705         __val = __val < __min ? __min: __val;   \
 706         __val > __max ? __max: __val; })
 707
 708
 709 /*
 710  * swap - swap value of @a and @b
 711  */
 712 #define swap(a, b) \
 713         do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 714
 715 /**
 716  * container_of - cast a member of a structure out to the containing structure
 717  * @ptr:        the pointer to the member.
 718  * @type:       the type of the container struct this is embedded in.
 719  * @member:     the name of the member within the struct.
 720  *
 721  */
 722 #define container_of(ptr, type, member) ({                      \
 723         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 724         (type *)( (char *)__mptr - offsetof(type,member) );})
 725
 726 struct sysinfo;
 727 extern int do_sysinfo(struct sysinfo *info);
 728
 729 #endif /* __KERNEL__ */
 730
 731 #ifndef __EXPORTED_HEADERS__
 732 #ifndef __KERNEL__
 733 #warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
 734 #endif /* __KERNEL__ */
 735 #endif /* __EXPORTED_HEADERS__ */
 736
 737 #define SI_LOAD_SHIFT   16
 738 struct sysinfo {
 739         long uptime;                    /* Seconds since boot */
 740         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 741         unsigned long totalram;         /* Total usable main memory size */
 742         unsigned long freeram;          /* Available memory size */
 743         unsigned long sharedram;        /* Amount of shared memory */
 744         unsigned long bufferram;        /* Memory used by buffers */
 745         unsigned long totalswap;        /* Total swap space size */
 746         unsigned long freeswap;         /* swap space still available */
 747         unsigned short procs;           /* Number of current processes */
 748         unsigned short pad;             /* explicit padding for m68k */
 749         unsigned long totalhigh;        /* Total high memory size */
 750         unsigned long freehigh;         /* Available high memory size */
 751         unsigned int mem_unit;          /* Memory unit size in bytes */
 752         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 753 };
 754
 755 /* Force a compilation error if condition is true */
 756 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
 757
 758 /* Force a compilation error if condition is constant and true */
 759 #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
 760
 761 /* Force a compilation error if a constant expression is not a power of 2 */
 762 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)                  \
 763         BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
 764
 765 /* Force a compilation error if condition is true, but also produce a
 766    result (of value 0 and type size_t), so the expression can be used
 767    e.g. in a structure initializer (or where-ever else comma expressions
 768    aren't permitted). */
 769 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
 770 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
 771
 772 /* Trap pasters of __FUNCTION__ at compile-time */
 773 #define __FUNCTION__ (__func__)
 774
 775 /* This helps us to avoid #ifdef CONFIG_NUMA */
 776 #ifdef CONFIG_NUMA
 777 #define NUMA_BUILD 1
 778 #else
 779 #define NUMA_BUILD 0
 780 #endif
 781
 782 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 783 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 784 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 785 #endif
 786
 787 #endif