1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
6 #include <linux/linkage.h>
7 #include <linux/stddef.h>
8 #include <linux/types.h>
9 #include <linux/compiler.h>
10 #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>
15 #include <asm/byteorder.h>
16 #include <uapi/linux/kernel.h>
18 #define USHRT_MAX ((u16)(~0U))
19 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
20 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
21 #define INT_MAX ((int)(~0U>>1))
22 #define INT_MIN (-INT_MAX - 1)
23 #define UINT_MAX (~0U)
24 #define LONG_MAX ((long)(~0UL>>1))
25 #define LONG_MIN (-LONG_MAX - 1)
26 #define ULONG_MAX (~0UL)
27 #define LLONG_MAX ((long long)(~0ULL>>1))
28 #define LLONG_MIN (-LLONG_MAX - 1)
29 #define ULLONG_MAX (~0ULL)
30 #define SIZE_MAX (~(size_t)0)
32 #define STACK_MAGIC 0xdeadbeef
34 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
36 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
37 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
38 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
39 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
41 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
44 * This looks more complex than it should be. But we need to
45 * get the type for the ~ right in round_down (it needs to be
46 * as wide as the result!), and we want to evaluate the macro
47 * arguments just once each.
49 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
50 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
51 #define round_down(x, y) ((x) & ~__round_mask(x, y))
53 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
54 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
55 #define DIV_ROUND_UP_ULL(ll,d) \
56 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
58 #if BITS_PER_LONG == 32
59 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
61 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
64 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
65 #define roundup(x, y) ( \
67 const typeof(y) __y = y; \
68 (((x) + (__y - 1)) / __y) * __y; \
71 #define rounddown(x, y) ( \
73 typeof(x) __x = (x); \
79 * Divide positive or negative dividend by positive divisor and round
80 * to closest integer. Result is undefined for negative divisors and
81 * for negative dividends if the divisor variable type is unsigned.
83 #define DIV_ROUND_CLOSEST(x, divisor)( \
86 typeof(divisor) __d = divisor; \
87 (((typeof(x))-1) > 0 || \
88 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
89 (((__x) + ((__d) / 2)) / (__d)) : \
90 (((__x) - ((__d) / 2)) / (__d)); \
95 * Multiplies an integer by a fraction, while avoiding unnecessary
96 * overflow or loss of precision.
98 #define mult_frac(x, numer, denom)( \
100 typeof(x) quot = (x) / (denom); \
101 typeof(x) rem = (x) % (denom); \
102 (quot * (numer)) + ((rem * (numer)) / (denom)); \
107 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
108 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
111 # include <asm/div64.h>
112 # define sector_div(a, b) do_div(a, b)
114 # define sector_div(n, b)( \
125 * upper_32_bits - return bits 32-63 of a number
126 * @n: the number we're accessing
128 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
129 * the "right shift count >= width of type" warning when that quantity is
132 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
135 * lower_32_bits - return bits 0-31 of a number
136 * @n: the number we're accessing
138 #define lower_32_bits(n) ((u32)(n))
144 #ifdef CONFIG_PREEMPT_VOLUNTARY
145 extern int _cond_resched(void);
146 # define might_resched() _cond_resched()
148 # define might_resched() do { } while (0)
151 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
152 void __might_sleep(const char *file
, int line
, int preempt_offset
);
154 * might_sleep - annotation for functions that can sleep
156 * this macro will print a stack trace if it is executed in an atomic
157 * context (spinlock, irq-handler, ...).
159 * This is a useful debugging help to be able to catch problems early and not
160 * be bitten later when the calling function happens to sleep when it is not
163 # define might_sleep() \
164 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
166 static inline void __might_sleep(const char *file
, int line
,
167 int preempt_offset
) { }
168 # define might_sleep() do { might_resched(); } while (0)
171 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
174 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
175 * input types abs() returns a signed long.
176 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
181 if (sizeof(x) == sizeof(long)) { \
183 ret = (__x < 0) ? -__x : __x; \
186 ret = (__x < 0) ? -__x : __x; \
191 #define abs64(x) ({ \
193 (__x < 0) ? -__x : __x; \
196 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)
197 void might_fault(void);
199 static inline void might_fault(void) { }
202 extern struct atomic_notifier_head panic_notifier_list
;
203 extern long (*panic_blink
)(int state
);
205 void panic(const char *fmt
, ...)
207 extern void oops_enter(void);
208 extern void oops_exit(void);
209 void print_oops_end_marker(void);
210 extern int oops_may_print(void);
211 void do_exit(long error_code
)
213 void complete_and_exit(struct completion
*, long)
216 /* Internal, do not use. */
217 int __must_check
_kstrtoul(const char *s
, unsigned int base
, unsigned long *res
);
218 int __must_check
_kstrtol(const char *s
, unsigned int base
, long *res
);
220 int __must_check
kstrtoull(const char *s
, unsigned int base
, unsigned long long *res
);
221 int __must_check
kstrtoll(const char *s
, unsigned int base
, long long *res
);
224 * kstrtoul - convert a string to an unsigned long
225 * @s: The start of the string. The string must be null-terminated, and may also
226 * include a single newline before its terminating null. The first character
227 * may also be a plus sign, but not a minus sign.
228 * @base: The number base to use. The maximum supported base is 16. If base is
229 * given as 0, then the base of the string is automatically detected with the
230 * conventional semantics - If it begins with 0x the number will be parsed as a
231 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
232 * parsed as an octal number. Otherwise it will be parsed as a decimal.
233 * @res: Where to write the result of the conversion on success.
235 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
236 * Used as a replacement for the obsolete simple_strtoull. Return code must
239 static inline int __must_check
kstrtoul(const char *s
, unsigned int base
, unsigned long *res
)
242 * We want to shortcut function call, but
243 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
245 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
246 __alignof__(unsigned long) == __alignof__(unsigned long long))
247 return kstrtoull(s
, base
, (unsigned long long *)res
);
249 return _kstrtoul(s
, base
, res
);
253 * kstrtol - convert a string to a long
254 * @s: The start of the string. The string must be null-terminated, and may also
255 * include a single newline before its terminating null. The first character
256 * may also be a plus sign or a minus sign.
257 * @base: The number base to use. The maximum supported base is 16. If base is
258 * given as 0, then the base of the string is automatically detected with the
259 * conventional semantics - If it begins with 0x the number will be parsed as a
260 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
261 * parsed as an octal number. Otherwise it will be parsed as a decimal.
262 * @res: Where to write the result of the conversion on success.
264 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
265 * Used as a replacement for the obsolete simple_strtoull. Return code must
268 static inline int __must_check
kstrtol(const char *s
, unsigned int base
, long *res
)
271 * We want to shortcut function call, but
272 * __builtin_types_compatible_p(long, long long) = 0.
274 if (sizeof(long) == sizeof(long long) &&
275 __alignof__(long) == __alignof__(long long))
276 return kstrtoll(s
, base
, (long long *)res
);
278 return _kstrtol(s
, base
, res
);
281 int __must_check
kstrtouint(const char *s
, unsigned int base
, unsigned int *res
);
282 int __must_check
kstrtoint(const char *s
, unsigned int base
, int *res
);
284 static inline int __must_check
kstrtou64(const char *s
, unsigned int base
, u64
*res
)
286 return kstrtoull(s
, base
, res
);
289 static inline int __must_check
kstrtos64(const char *s
, unsigned int base
, s64
*res
)
291 return kstrtoll(s
, base
, res
);
294 static inline int __must_check
kstrtou32(const char *s
, unsigned int base
, u32
*res
)
296 return kstrtouint(s
, base
, res
);
299 static inline int __must_check
kstrtos32(const char *s
, unsigned int base
, s32
*res
)
301 return kstrtoint(s
, base
, res
);
304 int __must_check
kstrtou16(const char *s
, unsigned int base
, u16
*res
);
305 int __must_check
kstrtos16(const char *s
, unsigned int base
, s16
*res
);
306 int __must_check
kstrtou8(const char *s
, unsigned int base
, u8
*res
);
307 int __must_check
kstrtos8(const char *s
, unsigned int base
, s8
*res
);
309 int __must_check
kstrtoull_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned long long *res
);
310 int __must_check
kstrtoll_from_user(const char __user
*s
, size_t count
, unsigned int base
, long long *res
);
311 int __must_check
kstrtoul_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned long *res
);
312 int __must_check
kstrtol_from_user(const char __user
*s
, size_t count
, unsigned int base
, long *res
);
313 int __must_check
kstrtouint_from_user(const char __user
*s
, size_t count
, unsigned int base
, unsigned int *res
);
314 int __must_check
kstrtoint_from_user(const char __user
*s
, size_t count
, unsigned int base
, int *res
);
315 int __must_check
kstrtou16_from_user(const char __user
*s
, size_t count
, unsigned int base
, u16
*res
);
316 int __must_check
kstrtos16_from_user(const char __user
*s
, size_t count
, unsigned int base
, s16
*res
);
317 int __must_check
kstrtou8_from_user(const char __user
*s
, size_t count
, unsigned int base
, u8
*res
);
318 int __must_check
kstrtos8_from_user(const char __user
*s
, size_t count
, unsigned int base
, s8
*res
);
320 static inline int __must_check
kstrtou64_from_user(const char __user
*s
, size_t count
, unsigned int base
, u64
*res
)
322 return kstrtoull_from_user(s
, count
, base
, res
);
325 static inline int __must_check
kstrtos64_from_user(const char __user
*s
, size_t count
, unsigned int base
, s64
*res
)
327 return kstrtoll_from_user(s
, count
, base
, res
);
330 static inline int __must_check
kstrtou32_from_user(const char __user
*s
, size_t count
, unsigned int base
, u32
*res
)
332 return kstrtouint_from_user(s
, count
, base
, res
);
335 static inline int __must_check
kstrtos32_from_user(const char __user
*s
, size_t count
, unsigned int base
, s32
*res
)
337 return kstrtoint_from_user(s
, count
, base
, res
);
340 /* Obsolete, do not use. Use kstrto<foo> instead */
342 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
343 extern long simple_strtol(const char *,char **,unsigned int);
344 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
345 extern long long simple_strtoll(const char *,char **,unsigned int);
346 #define strict_strtoul kstrtoul
347 #define strict_strtol kstrtol
348 #define strict_strtoull kstrtoull
349 #define strict_strtoll kstrtoll
351 extern int num_to_str(char *buf
, int size
, unsigned long long num
);
353 /* lib/printf utilities */
355 extern __printf(2, 3) int sprintf(char *buf
, const char * fmt
, ...);
356 extern __printf(2, 0) int vsprintf(char *buf
, const char *, va_list);
357 extern __printf(3, 4)
358 int snprintf(char *buf
, size_t size
, const char *fmt
, ...);
359 extern __printf(3, 0)
360 int vsnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
);
361 extern __printf(3, 4)
362 int scnprintf(char *buf
, size_t size
, const char *fmt
, ...);
363 extern __printf(3, 0)
364 int vscnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
);
365 extern __printf(2, 3)
366 char *kasprintf(gfp_t gfp
, const char *fmt
, ...);
367 extern char *kvasprintf(gfp_t gfp
, const char *fmt
, va_list args
);
370 int sscanf(const char *, const char *, ...);
372 int vsscanf(const char *, const char *, va_list);
374 extern int get_option(char **str
, int *pint
);
375 extern char *get_options(const char *str
, int nints
, int *ints
);
376 extern unsigned long long memparse(const char *ptr
, char **retptr
);
378 extern int core_kernel_text(unsigned long addr
);
379 extern int core_kernel_data(unsigned long addr
);
380 extern int __kernel_text_address(unsigned long addr
);
381 extern int kernel_text_address(unsigned long addr
);
382 extern int func_ptr_is_kernel_text(void *ptr
);
385 extern struct pid
*session_of_pgrp(struct pid
*pgrp
);
387 unsigned long int_sqrt(unsigned long);
389 extern void bust_spinlocks(int yes
);
390 extern int oops_in_progress
; /* If set, an oops, panic(), BUG() or die() is in progress */
391 extern int panic_timeout
;
392 extern int panic_on_oops
;
393 extern int panic_on_unrecovered_nmi
;
394 extern int panic_on_io_nmi
;
395 extern int sysctl_panic_on_stackoverflow
;
396 extern const char *print_tainted(void);
399 LOCKDEP_NOW_UNRELIABLE
401 extern void add_taint(unsigned flag
, enum lockdep_ok
);
402 extern int test_taint(unsigned flag
);
403 extern unsigned long get_taint(void);
404 extern int root_mountflags
;
406 extern bool early_boot_irqs_disabled
;
408 /* Values used for system_state */
409 extern enum system_states
{
417 #define TAINT_PROPRIETARY_MODULE 0
418 #define TAINT_FORCED_MODULE 1
419 #define TAINT_UNSAFE_SMP 2
420 #define TAINT_FORCED_RMMOD 3
421 #define TAINT_MACHINE_CHECK 4
422 #define TAINT_BAD_PAGE 5
425 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
427 #define TAINT_CRAP 10
428 #define TAINT_FIRMWARE_WORKAROUND 11
429 #define TAINT_OOT_MODULE 12
431 extern const char hex_asc
[];
432 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
433 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
435 static inline char *hex_byte_pack(char *buf
, u8 byte
)
437 *buf
++ = hex_asc_hi(byte
);
438 *buf
++ = hex_asc_lo(byte
);
442 extern const char hex_asc_upper
[];
443 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
444 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
446 static inline char *hex_byte_pack_upper(char *buf
, u8 byte
)
448 *buf
++ = hex_asc_upper_hi(byte
);
449 *buf
++ = hex_asc_upper_lo(byte
);
453 static inline char * __deprecated
pack_hex_byte(char *buf
, u8 byte
)
455 return hex_byte_pack(buf
, byte
);
458 extern int hex_to_bin(char ch
);
459 extern int __must_check
hex2bin(u8
*dst
, const char *src
, size_t count
);
461 int mac_pton(const char *s
, u8
*mac
);
464 * General tracing related utility functions - trace_printk(),
465 * tracing_on/tracing_off and tracing_start()/tracing_stop
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.
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.
480 * Most likely, you want to use tracing_on/tracing_off.
482 #ifdef CONFIG_RING_BUFFER
483 /* trace_off_permanent stops recording with no way to bring it back */
484 void tracing_off_permanent(void);
486 static inline void tracing_off_permanent(void) { }
489 enum ftrace_dump_mode
{
495 #ifdef CONFIG_TRACING
496 void tracing_on(void);
497 void tracing_off(void);
498 int tracing_is_on(void);
499 void tracing_snapshot(void);
500 void tracing_snapshot_alloc(void);
502 extern void tracing_start(void);
503 extern void tracing_stop(void);
504 extern void ftrace_off_permanent(void);
506 static inline __printf(1, 2)
507 void ____trace_printk_check_format(const char *fmt
, ...)
510 #define __trace_printk_check_format(fmt, args...) \
513 ____trace_printk_check_format(fmt, ##args); \
517 * trace_printk - printf formatting in the ftrace buffer
518 * @fmt: the printf format for printing
520 * Note: __trace_printk is an internal function for trace_printk and
521 * the @ip is passed in via the trace_printk macro.
523 * This function allows a kernel developer to debug fast path sections
524 * that printk is not appropriate for. By scattering in various
525 * printk like tracing in the code, a developer can quickly see
526 * where problems are occurring.
528 * This is intended as a debugging tool for the developer only.
529 * Please refrain from leaving trace_printks scattered around in
530 * your code. (Extra memory is used for special buffers that are
531 * allocated when trace_printk() is used)
533 * A little optization trick is done here. If there's only one
534 * argument, there's no need to scan the string for printf formats.
535 * The trace_puts() will suffice. But how can we take advantage of
536 * using trace_puts() when trace_printk() has only one argument?
537 * By stringifying the args and checking the size we can tell
538 * whether or not there are args. __stringify((__VA_ARGS__)) will
539 * turn into "()\0" with a size of 3 when there are no args, anything
540 * else will be bigger. All we need to do is define a string to this,
541 * and then take its size and compare to 3. If it's bigger, use
542 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
543 * let gcc optimize the rest.
546 #define trace_printk(fmt, ...) \
548 char _______STR[] = __stringify((__VA_ARGS__)); \
549 if (sizeof(_______STR) > 3) \
550 do_trace_printk(fmt, ##__VA_ARGS__); \
555 #define do_trace_printk(fmt, args...) \
557 static const char *trace_printk_fmt \
558 __attribute__((section("__trace_printk_fmt"))) = \
559 __builtin_constant_p(fmt) ? fmt : NULL; \
561 __trace_printk_check_format(fmt, ##args); \
563 if (__builtin_constant_p(fmt)) \
564 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
566 __trace_printk(_THIS_IP_, fmt, ##args); \
569 extern __printf(2, 3)
570 int __trace_bprintk(unsigned long ip
, const char *fmt
, ...);
572 extern __printf(2, 3)
573 int __trace_printk(unsigned long ip
, const char *fmt
, ...);
576 * trace_puts - write a string into the ftrace buffer
577 * @str: the string to record
579 * Note: __trace_bputs is an internal function for trace_puts and
580 * the @ip is passed in via the trace_puts macro.
582 * This is similar to trace_printk() but is made for those really fast
583 * paths that a developer wants the least amount of "Heisenbug" affects,
584 * where the processing of the print format is still too much.
586 * This function allows a kernel developer to debug fast path sections
587 * that printk is not appropriate for. By scattering in various
588 * printk like tracing in the code, a developer can quickly see
589 * where problems are occurring.
591 * This is intended as a debugging tool for the developer only.
592 * Please refrain from leaving trace_puts scattered around in
593 * your code. (Extra memory is used for special buffers that are
594 * allocated when trace_puts() is used)
596 * Returns: 0 if nothing was written, positive # if string was.
597 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
600 #define trace_puts(str) ({ \
601 static const char *trace_printk_fmt \
602 __attribute__((section("__trace_printk_fmt"))) = \
603 __builtin_constant_p(str) ? str : NULL; \
605 if (__builtin_constant_p(str)) \
606 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
608 __trace_puts(_THIS_IP_, str, strlen(str)); \
610 extern int __trace_bputs(unsigned long ip
, const char *str
);
611 extern int __trace_puts(unsigned long ip
, const char *str
, int size
);
613 extern void trace_dump_stack(int skip
);
616 * The double __builtin_constant_p is because gcc will give us an error
617 * if we try to allocate the static variable to fmt if it is not a
618 * constant. Even with the outer if statement.
620 #define ftrace_vprintk(fmt, vargs) \
622 if (__builtin_constant_p(fmt)) { \
623 static const char *trace_printk_fmt \
624 __attribute__((section("__trace_printk_fmt"))) = \
625 __builtin_constant_p(fmt) ? fmt : NULL; \
627 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
629 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
633 __ftrace_vbprintk(unsigned long ip
, const char *fmt
, va_list ap
);
636 __ftrace_vprintk(unsigned long ip
, const char *fmt
, va_list ap
);
638 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode
);
640 static inline void tracing_start(void) { }
641 static inline void tracing_stop(void) { }
642 static inline void ftrace_off_permanent(void) { }
643 static inline void trace_dump_stack(int skip
) { }
645 static inline void tracing_on(void) { }
646 static inline void tracing_off(void) { }
647 static inline int tracing_is_on(void) { return 0; }
648 static inline void tracing_snapshot(void) { }
649 static inline void tracing_snapshot_alloc(void) { }
651 static inline __printf(1, 2)
652 int trace_printk(const char *fmt
, ...)
657 ftrace_vprintk(const char *fmt
, va_list ap
)
661 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode
) { }
662 #endif /* CONFIG_TRACING */
665 * min()/max()/clamp() macros that also do
666 * strict type-checking.. See the
667 * "unnecessary" pointer comparison.
669 #define min(x, y) ({ \
670 typeof(x) _min1 = (x); \
671 typeof(y) _min2 = (y); \
672 (void) (&_min1 == &_min2); \
673 _min1 < _min2 ? _min1 : _min2; })
675 #define max(x, y) ({ \
676 typeof(x) _max1 = (x); \
677 typeof(y) _max2 = (y); \
678 (void) (&_max1 == &_max2); \
679 _max1 > _max2 ? _max1 : _max2; })
681 #define min3(x, y, z) ({ \
682 typeof(x) _min1 = (x); \
683 typeof(y) _min2 = (y); \
684 typeof(z) _min3 = (z); \
685 (void) (&_min1 == &_min2); \
686 (void) (&_min1 == &_min3); \
687 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
688 (_min2 < _min3 ? _min2 : _min3); })
690 #define max3(x, y, z) ({ \
691 typeof(x) _max1 = (x); \
692 typeof(y) _max2 = (y); \
693 typeof(z) _max3 = (z); \
694 (void) (&_max1 == &_max2); \
695 (void) (&_max1 == &_max3); \
696 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
697 (_max2 > _max3 ? _max2 : _max3); })
700 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
704 #define min_not_zero(x, y) ({ \
705 typeof(x) __x = (x); \
706 typeof(y) __y = (y); \
707 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
710 * clamp - return a value clamped to a given range with strict typechecking
711 * @val: current value
712 * @min: minimum allowable value
713 * @max: maximum allowable value
715 * This macro does strict typechecking of min/max to make sure they are of the
716 * same type as val. See the unnecessary pointer comparisons.
718 #define clamp(val, min, max) ({ \
719 typeof(val) __val = (val); \
720 typeof(min) __min = (min); \
721 typeof(max) __max = (max); \
722 (void) (&__val == &__min); \
723 (void) (&__val == &__max); \
724 __val = __val < __min ? __min: __val; \
725 __val > __max ? __max: __val; })
728 * ..and if you can't take the strict
729 * types, you can specify one yourself.
731 * Or not use min/max/clamp at all, of course.
733 #define min_t(type, x, y) ({ \
736 __min1 < __min2 ? __min1: __min2; })
738 #define max_t(type, x, y) ({ \
741 __max1 > __max2 ? __max1: __max2; })
744 * clamp_t - return a value clamped to a given range using a given type
745 * @type: the type of variable to use
746 * @val: current value
747 * @min: minimum allowable value
748 * @max: maximum allowable value
750 * This macro does no typechecking and uses temporary variables of type
751 * 'type' to make all the comparisons.
753 #define clamp_t(type, val, min, max) ({ \
754 type __val = (val); \
755 type __min = (min); \
756 type __max = (max); \
757 __val = __val < __min ? __min: __val; \
758 __val > __max ? __max: __val; })
761 * clamp_val - return a value clamped to a given range using val's type
762 * @val: current value
763 * @min: minimum allowable value
764 * @max: maximum allowable value
766 * This macro does no typechecking and uses temporary variables of whatever
767 * type the input argument 'val' is. This is useful when val is an unsigned
768 * type and min and max are literals that will otherwise be assigned a signed
771 #define clamp_val(val, min, max) ({ \
772 typeof(val) __val = (val); \
773 typeof(val) __min = (min); \
774 typeof(val) __max = (max); \
775 __val = __val < __min ? __min: __val; \
776 __val > __max ? __max: __val; })
780 * swap - swap value of @a and @b
783 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
786 * container_of - cast a member of a structure out to the containing structure
787 * @ptr: the pointer to the member.
788 * @type: the type of the container struct this is embedded in.
789 * @member: the name of the member within the struct.
792 #define container_of(ptr, type, member) ({ \
793 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
794 (type *)( (char *)__mptr - offsetof(type,member) );})
796 /* Trap pasters of __FUNCTION__ at compile-time */
797 #define __FUNCTION__ (__func__)
799 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
800 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
801 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD