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