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