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