kernel.h 21.2 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10
#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H


#include <stdarg.h>
#include <linux/linkage.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/bitops.h>
11
#include <linux/log2.h>
12
#include <linux/typecheck.h>
13
#include <linux/printk.h>
14
#include <linux/dynamic_debug.h>
L
Linus Torvalds 已提交
15
#include <asm/byteorder.h>
16
#include <uapi/linux/kernel.h>
L
Linus Torvalds 已提交
17

18 19 20
#define USHRT_MAX	((u16)(~0U))
#define SHRT_MAX	((s16)(USHRT_MAX>>1))
#define SHRT_MIN	((s16)(-SHRT_MAX - 1))
L
Linus Torvalds 已提交
21 22 23 24 25 26
#define INT_MAX		((int)(~0U>>1))
#define INT_MIN		(-INT_MAX - 1)
#define UINT_MAX	(~0U)
#define LONG_MAX	((long)(~0UL>>1))
#define LONG_MIN	(-LONG_MAX - 1)
#define ULONG_MAX	(~0UL)
27 28 29
#define LLONG_MAX	((long long)(~0ULL>>1))
#define LLONG_MIN	(-LLONG_MAX - 1)
#define ULLONG_MAX	(~0ULL)
X
Xi Wang 已提交
30
#define SIZE_MAX	(~(size_t)0)
L
Linus Torvalds 已提交
31 32 33

#define STACK_MAGIC	0xdeadbeef

34 35
#define REPEAT_BYTE(x)	((~0ul / 0xff) * (x))

36
#define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
A
Alexey Dobriyan 已提交
37
#define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
M
Matthew Wilcox 已提交
38
#define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
H
Herbert Xu 已提交
39
#define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
L
Linus Torvalds 已提交
40

R
Rusty Russell 已提交
41 42
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

Y
Yinghai Lu 已提交
43 44 45 46 47 48 49 50 51 52
/*
 * This looks more complex than it should be. But we need to
 * get the type for the ~ right in round_down (it needs to be
 * as wide as the result!), and we want to evaluate the macro
 * arguments just once each.
 */
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))

53
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
S
Steven Whitehouse 已提交
54
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
55 56 57 58 59 60 61 62
#define DIV_ROUND_UP_ULL(ll,d) \
	({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })

#if BITS_PER_LONG == 32
# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
#else
# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
#endif
63 64

/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
65 66
#define roundup(x, y) (					\
{							\
67
	const typeof(y) __y = y;			\
68 69 70
	(((x) + (__y - 1)) / __y) * __y;		\
}							\
)
E
Eric Paris 已提交
71 72 73 74 75 76
#define rounddown(x, y) (				\
{							\
	typeof(x) __x = (x);				\
	__x - (__x % (y));				\
}							\
)
77 78 79 80 81

/*
 * Divide positive or negative dividend by positive divisor and round
 * to closest integer. Result is undefined for negative divisors.
 */
82 83
#define DIV_ROUND_CLOSEST(x, divisor)(			\
{							\
84 85
	typeof(x) __x = x;				\
	typeof(divisor) __d = divisor;			\
86
	(((typeof(x))-1) > 0 || (__x) > 0) ?		\
87 88
		(((__x) + ((__d) / 2)) / (__d)) :	\
		(((__x) - ((__d) / 2)) / (__d));	\
89 90
}							\
)
L
Linus Torvalds 已提交
91

92 93 94 95 96 97 98 99 100 101 102 103 104
/*
 * Multiplies an integer by a fraction, while avoiding unnecessary
 * overflow or loss of precision.
 */
#define mult_frac(x, numer, denom)(			\
{							\
	typeof(x) quot = (x) / (denom);			\
	typeof(x) rem  = (x) % (denom);			\
	(quot * (numer)) + ((rem * (numer)) / (denom));	\
}							\
)


105 106 107
#define _RET_IP_		(unsigned long)__builtin_return_address(0)
#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })

108
#ifdef CONFIG_LBDAF
109 110 111 112 113 114 115 116 117 118 119 120 121
# include <asm/div64.h>
# define sector_div(a, b) do_div(a, b)
#else
# define sector_div(n, b)( \
{ \
	int _res; \
	_res = (n) % (b); \
	(n) /= (b); \
	_res; \
} \
)
#endif

A
Andrew Morton 已提交
122 123 124 125 126 127 128 129 130 131
/**
 * upper_32_bits - return bits 32-63 of a number
 * @n: the number we're accessing
 *
 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
 * the "right shift count >= width of type" warning when that quantity is
 * 32-bits.
 */
#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))

J
Joerg Roedel 已提交
132 133 134 135 136 137
/**
 * lower_32_bits - return bits 0-31 of a number
 * @n: the number we're accessing
 */
#define lower_32_bits(n) ((u32)(n))

L
Linus Torvalds 已提交
138
struct completion;
A
akpm@osdl.org 已提交
139 140
struct pt_regs;
struct user;
L
Linus Torvalds 已提交
141

142 143 144 145 146 147 148
#ifdef CONFIG_PREEMPT_VOLUNTARY
extern int _cond_resched(void);
# define might_resched() _cond_resched()
#else
# define might_resched() do { } while (0)
#endif

149
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
150
  void __might_sleep(const char *file, int line, int preempt_offset);
L
Linus Torvalds 已提交
151 152 153 154 155 156 157
/**
 * might_sleep - annotation for functions that can sleep
 *
 * this macro will print a stack trace if it is executed in an atomic
 * context (spinlock, irq-handler, ...).
 *
 * This is a useful debugging help to be able to catch problems early and not
158
 * be bitten later when the calling function happens to sleep when it is not
L
Linus Torvalds 已提交
159 160
 * supposed to.
 */
161
# define might_sleep() \
162
	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
L
Linus Torvalds 已提交
163
#else
164 165
  static inline void __might_sleep(const char *file, int line,
				   int preempt_offset) { }
166
# define might_sleep() do { might_resched(); } while (0)
L
Linus Torvalds 已提交
167 168
#endif

169
#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
170

171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186
/*
 * abs() handles unsigned and signed longs, ints, shorts and chars.  For all
 * input types abs() returns a signed long.
 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
 * for those.
 */
#define abs(x) ({						\
		long ret;					\
		if (sizeof(x) == sizeof(long)) {		\
			long __x = (x);				\
			ret = (__x < 0) ? -__x : __x;		\
		} else {					\
			int __x = (x);				\
			ret = (__x < 0) ? -__x : __x;		\
		}						\
		ret;						\
L
Linus Torvalds 已提交
187 188
	})

189 190 191 192 193
#define abs64(x) ({				\
		s64 __x = (x);			\
		(__x < 0) ? -__x : __x;		\
	})

194 195 196 197 198 199 200 201 202
#ifdef CONFIG_PROVE_LOCKING
void might_fault(void);
#else
static inline void might_fault(void)
{
	might_sleep();
}
#endif

203
extern struct atomic_notifier_head panic_notifier_list;
204
extern long (*panic_blink)(int state);
205
__printf(1, 2)
J
Joe Perches 已提交
206
void panic(const char *fmt, ...)
207
	__noreturn __cold;
208 209
extern void oops_enter(void);
extern void oops_exit(void);
210
void print_oops_end_marker(void);
211
extern int oops_may_print(void);
212
void do_exit(long error_code)
213
	__noreturn;
214
void complete_and_exit(struct completion *, long)
215
	__noreturn;
216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276

/* Internal, do not use. */
int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
int __must_check _kstrtol(const char *s, unsigned int base, long *res);

int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
{
	/*
	 * We want to shortcut function call, but
	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
	 */
	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
	    __alignof__(unsigned long) == __alignof__(unsigned long long))
		return kstrtoull(s, base, (unsigned long long *)res);
	else
		return _kstrtoul(s, base, res);
}

static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
{
	/*
	 * We want to shortcut function call, but
	 * __builtin_types_compatible_p(long, long long) = 0.
	 */
	if (sizeof(long) == sizeof(long long) &&
	    __alignof__(long) == __alignof__(long long))
		return kstrtoll(s, base, (long long *)res);
	else
		return _kstrtol(s, base, res);
}

int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
int __must_check kstrtoint(const char *s, unsigned int base, int *res);

static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
{
	return kstrtoull(s, base, res);
}

static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
{
	return kstrtoll(s, base, res);
}

static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
{
	return kstrtouint(s, base, res);
}

static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
{
	return kstrtoint(s, base, res);
}

int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);

A
Alexey Dobriyan 已提交
277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307
int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);

static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
{
	return kstrtoull_from_user(s, count, base, res);
}

static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
{
	return kstrtoll_from_user(s, count, base, res);
}

static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
{
	return kstrtouint_from_user(s, count, base, res);
}

static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
{
	return kstrtoint_from_user(s, count, base, res);
}

308 309
/* Obsolete, do not use.  Use kstrto<foo> instead */

L
Linus Torvalds 已提交
310 311 312 313
extern unsigned long simple_strtoul(const char *,char **,unsigned int);
extern long simple_strtol(const char *,char **,unsigned int);
extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
extern long long simple_strtoll(const char *,char **,unsigned int);
314 315 316 317 318
#define strict_strtoul	kstrtoul
#define strict_strtol	kstrtol
#define strict_strtoull	kstrtoull
#define strict_strtoll	kstrtoll

319 320
extern int num_to_str(char *buf, int size, unsigned long long num);

321 322
/* lib/printf utilities */

323 324 325 326 327 328 329 330 331 332 333 334
extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
extern __printf(3, 4)
int snprintf(char *buf, size_t size, const char *fmt, ...);
extern __printf(3, 0)
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
extern __printf(3, 4)
int scnprintf(char *buf, size_t size, const char *fmt, ...);
extern __printf(3, 0)
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
extern __printf(2, 3)
char *kasprintf(gfp_t gfp, const char *fmt, ...);
J
Jeremy Fitzhardinge 已提交
335
extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
L
Linus Torvalds 已提交
336

337 338 339 340
extern __scanf(2, 3)
int sscanf(const char *, const char *, ...);
extern __scanf(2, 0)
int vsscanf(const char *, const char *, va_list);
L
Linus Torvalds 已提交
341 342 343

extern int get_option(char **str, int *pint);
extern char *get_options(const char *str, int nints, int *ints);
344
extern unsigned long long memparse(const char *ptr, char **retptr);
L
Linus Torvalds 已提交
345

346
extern int core_kernel_text(unsigned long addr);
347
extern int core_kernel_data(unsigned long addr);
L
Linus Torvalds 已提交
348 349
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
350 351
extern int func_ptr_is_kernel_text(void *ptr);

352 353
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);
L
Linus Torvalds 已提交
354 355 356 357

unsigned long int_sqrt(unsigned long);

extern void bust_spinlocks(int yes);
358
extern void wake_up_klogd(void);
L
Linus Torvalds 已提交
359
extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
360
extern int panic_timeout;
L
Linus Torvalds 已提交
361
extern int panic_on_oops;
362
extern int panic_on_unrecovered_nmi;
363
extern int panic_on_io_nmi;
364
extern int sysctl_panic_on_stackoverflow;
L
Linus Torvalds 已提交
365
extern const char *print_tainted(void);
A
Andi Kleen 已提交
366 367 368
extern void add_taint(unsigned flag);
extern int test_taint(unsigned flag);
extern unsigned long get_taint(void);
369
extern int root_mountflags;
L
Linus Torvalds 已提交
370

371 372
extern bool early_boot_irqs_disabled;

L
Linus Torvalds 已提交
373 374 375 376 377 378 379 380 381
/* Values used for system_state */
extern enum system_states {
	SYSTEM_BOOTING,
	SYSTEM_RUNNING,
	SYSTEM_HALT,
	SYSTEM_POWER_OFF,
	SYSTEM_RESTART,
} system_state;

A
Andi Kleen 已提交
382 383 384 385 386 387 388 389 390 391
#define TAINT_PROPRIETARY_MODULE	0
#define TAINT_FORCED_MODULE		1
#define TAINT_UNSAFE_SMP		2
#define TAINT_FORCED_RMMOD		3
#define TAINT_MACHINE_CHECK		4
#define TAINT_BAD_PAGE			5
#define TAINT_USER			6
#define TAINT_DIE			7
#define TAINT_OVERRIDDEN_ACPI_TABLE	8
#define TAINT_WARN			9
392
#define TAINT_CRAP			10
393
#define TAINT_FIRMWARE_WORKAROUND	11
394
#define TAINT_OOT_MODULE		12
L
Linus Torvalds 已提交
395

396 397 398 399
extern const char hex_asc[];
#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]

400
static inline char *hex_byte_pack(char *buf, u8 byte)
401 402 403 404 405
{
	*buf++ = hex_asc_hi(byte);
	*buf++ = hex_asc_lo(byte);
	return buf;
}
R
Randy Dunlap 已提交
406

407 408 409 410 411
static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
{
	return hex_byte_pack(buf, byte);
}

412
extern int hex_to_bin(char ch);
M
Mimi Zohar 已提交
413
extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
414

415 416
/*
 * General tracing related utility functions - trace_printk(),
417 418 419 420
 * tracing_on/tracing_off and tracing_start()/tracing_stop
 *
 * Use tracing_on/tracing_off when you want to quickly turn on or off
 * tracing. It simply enables or disables the recording of the trace events.
421
 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
422 423 424 425 426 427 428 429 430 431 432
 * file, which gives a means for the kernel and userspace to interact.
 * Place a tracing_off() in the kernel where you want tracing to end.
 * From user space, examine the trace, and then echo 1 > tracing_on
 * to continue tracing.
 *
 * tracing_stop/tracing_start has slightly more overhead. It is used
 * by things like suspend to ram where disabling the recording of the
 * trace is not enough, but tracing must actually stop because things
 * like calling smp_processor_id() may crash the system.
 *
 * Most likely, you want to use tracing_on/tracing_off.
433
 */
434 435 436 437 438 439
#ifdef CONFIG_RING_BUFFER
/* trace_off_permanent stops recording with no way to bring it back */
void tracing_off_permanent(void);
#else
static inline void tracing_off_permanent(void) { }
#endif
440 441 442 443 444 445 446

enum ftrace_dump_mode {
	DUMP_NONE,
	DUMP_ALL,
	DUMP_ORIG,
};

447
#ifdef CONFIG_TRACING
448 449 450 451
void tracing_on(void);
void tracing_off(void);
int tracing_is_on(void);

452 453 454 455
extern void tracing_start(void);
extern void tracing_stop(void);
extern void ftrace_off_permanent(void);

456 457
static inline __printf(1, 2)
void ____trace_printk_check_format(const char *fmt, ...)
458 459 460 461 462 463 464 465
{
}
#define __trace_printk_check_format(fmt, args...)			\
do {									\
	if (0)								\
		____trace_printk_check_format(fmt, ##args);		\
} while (0)

466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481
/**
 * trace_printk - printf formatting in the ftrace buffer
 * @fmt: the printf format for printing
 *
 * Note: __trace_printk is an internal function for trace_printk and
 *       the @ip is passed in via the trace_printk macro.
 *
 * This function allows a kernel developer to debug fast path sections
 * that printk is not appropriate for. By scattering in various
 * printk like tracing in the code, a developer can quickly see
 * where problems are occurring.
 *
 * This is intended as a debugging tool for the developer only.
 * Please refrain from leaving trace_printks scattered around in
 * your code.
 */
482 483 484

#define trace_printk(fmt, args...)					\
do {									\
485 486 487 488
	static const char *trace_printk_fmt				\
		__attribute__((section("__trace_printk_fmt"))) =	\
		__builtin_constant_p(fmt) ? fmt : NULL;			\
									\
489
	__trace_printk_check_format(fmt, ##args);			\
490
									\
491
	if (__builtin_constant_p(fmt))					\
492
		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
493 494
	else								\
		__trace_printk(_THIS_IP_, fmt, ##args);			\
495 496
} while (0)

497 498
extern __printf(2, 3)
int __trace_bprintk(unsigned long ip, const char *fmt, ...);
499

500 501
extern __printf(2, 3)
int __trace_printk(unsigned long ip, const char *fmt, ...);
502

S
Steven Rostedt 已提交
503 504
extern void trace_dump_stack(void);

505 506 507 508 509
/*
 * The double __builtin_constant_p is because gcc will give us an error
 * if we try to allocate the static variable to fmt if it is not a
 * constant. Even with the outer if statement.
 */
510 511
#define ftrace_vprintk(fmt, vargs)					\
do {									\
512 513 514 515
	if (__builtin_constant_p(fmt)) {				\
		static const char *trace_printk_fmt			\
		  __attribute__((section("__trace_printk_fmt"))) =	\
			__builtin_constant_p(fmt) ? fmt : NULL;		\
I
Ingo Molnar 已提交
516
									\
517 518 519
		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
	} else								\
		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
520 521
} while (0)

522 523 524
extern int
__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);

525 526
extern int
__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
527

528
extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
529
#else
530 531
static inline __printf(1, 2)
int trace_printk(const char *fmt, ...);
532 533 534 535

static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
static inline void ftrace_off_permanent(void) { }
536
static inline void trace_dump_stack(void) { }
537 538 539 540 541

static inline void tracing_on(void) { }
static inline void tracing_off(void) { }
static inline int tracing_is_on(void) { return 0; }

542 543 544 545 546 547 548 549 550 551
static inline int
trace_printk(const char *fmt, ...)
{
	return 0;
}
static inline int
ftrace_vprintk(const char *fmt, va_list ap)
{
	return 0;
}
552
static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
553
#endif /* CONFIG_TRACING */
554

L
Linus Torvalds 已提交
555
/*
556
 * min()/max()/clamp() macros that also do
L
Linus Torvalds 已提交
557 558 559
 * strict type-checking.. See the
 * "unnecessary" pointer comparison.
 */
560 561 562 563 564 565 566 567 568 569 570 571
#define min(x, y) ({				\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })

#define max(x, y) ({				\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })

572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589
#define min3(x, y, z) ({			\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	typeof(z) _min3 = (z);			\
	(void) (&_min1 == &_min2);		\
	(void) (&_min1 == &_min3);		\
	_min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
		(_min2 < _min3 ? _min2 : _min3); })

#define max3(x, y, z) ({			\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	typeof(z) _max3 = (z);			\
	(void) (&_max1 == &_max2);		\
	(void) (&_max1 == &_max3);		\
	_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
		(_max2 > _max3 ? _max2 : _max3); })

M
Martin K. Petersen 已提交
590 591 592 593 594 595 596 597 598 599
/**
 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
 * @x: value1
 * @y: value2
 */
#define min_not_zero(x, y) ({			\
	typeof(x) __x = (x);			\
	typeof(y) __y = (y);			\
	__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })

600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
/**
 * clamp - return a value clamped to a given range with strict typechecking
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does strict typechecking of min/max to make sure they are of the
 * same type as val.  See the unnecessary pointer comparisons.
 */
#define clamp(val, min, max) ({			\
	typeof(val) __val = (val);		\
	typeof(min) __min = (min);		\
	typeof(max) __max = (max);		\
	(void) (&__val == &__min);		\
	(void) (&__val == &__max);		\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })
L
Linus Torvalds 已提交
617 618 619 620 621

/*
 * ..and if you can't take the strict
 * types, you can specify one yourself.
 *
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
 * Or not use min/max/clamp at all, of course.
 */
#define min_t(type, x, y) ({			\
	type __min1 = (x);			\
	type __min2 = (y);			\
	__min1 < __min2 ? __min1: __min2; })

#define max_t(type, x, y) ({			\
	type __max1 = (x);			\
	type __max2 = (y);			\
	__max1 > __max2 ? __max1: __max2; })

/**
 * clamp_t - return a value clamped to a given range using a given type
 * @type: the type of variable to use
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of type
 * 'type' to make all the comparisons.
L
Linus Torvalds 已提交
643
 */
644 645 646 647 648 649
#define clamp_t(type, val, min, max) ({		\
	type __val = (val);			\
	type __min = (min);			\
	type __max = (max);			\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })
L
Linus Torvalds 已提交
650

651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667
/**
 * clamp_val - return a value clamped to a given range using val's type
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of whatever
 * type the input argument 'val' is.  This is useful when val is an unsigned
 * type and min and max are literals that will otherwise be assigned a signed
 * integer type.
 */
#define clamp_val(val, min, max) ({		\
	typeof(val) __val = (val);		\
	typeof(val) __min = (min);		\
	typeof(val) __max = (max);		\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })
L
Linus Torvalds 已提交
668

669 670 671 672

/*
 * swap - swap value of @a and @b
 */
673 674
#define swap(a, b) \
	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
675

L
Linus Torvalds 已提交
676 677 678 679 680 681 682 683
/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:	the pointer to the member.
 * @type:	the type of the container struct this is embedded in.
 * @member:	the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({			\
684 685
	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
	(type *)( (char *)__mptr - offsetof(type,member) );})
L
Linus Torvalds 已提交
686

687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)

/* This helps us to avoid #ifdef CONFIG_NUMA */
#ifdef CONFIG_NUMA
#define NUMA_BUILD 1
#else
#define NUMA_BUILD 0
#endif

/* This helps us avoid #ifdef CONFIG_COMPACTION */
#ifdef CONFIG_COMPACTION
#define COMPACTION_BUILD 1
#else
#define COMPACTION_BUILD 0
#endif

/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
#endif
708 709 710

extern int do_sysinfo(struct sysinfo *info);

L
Linus Torvalds 已提交
711
#endif