1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 #include <linux/sysinfo.h>
5 
6 /*
7  * 'kernel.h' contains some often-used function prototypes etc
8  */
9 #define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
10 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
11 
12 #ifdef __KERNEL__
13 
14 #include <stdarg.h>
15 #include <linux/linkage.h>
16 #include <linux/stddef.h>
17 #include <linux/types.h>
18 #include <linux/compiler.h>
19 #include <linux/bitops.h>
20 #include <linux/log2.h>
21 #include <linux/typecheck.h>
22 #include <linux/printk.h>
23 #include <linux/dynamic_debug.h>
24 #include <asm/byteorder.h>
25 
26 #define USHRT_MAX	((u16)(~0U))
27 #define SHRT_MAX	((s16)(USHRT_MAX>>1))
28 #define SHRT_MIN	((s16)(-SHRT_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_KERNEL((x), (a))
42 #define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (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 /*
49  * This looks more complex than it should be. But we need to
50  * get the type for the ~ right in round_down (it needs to be
51  * as wide as the result!), and we want to evaluate the macro
52  * arguments just once each.
53  */
54 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
55 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
56 #define round_down(x, y) ((x) & ~__round_mask(x, y))
57 
58 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
59 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
60 #define DIV_ROUND_UP_ULL(ll,d) \
61 	({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
62 
63 #if BITS_PER_LONG == 32
64 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
65 #else
66 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
67 #endif
68 
69 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
70 #define roundup(x, y) (					\
71 {							\
72 	const typeof(y) __y = y;			\
73 	(((x) + (__y - 1)) / __y) * __y;		\
74 }							\
75 )
76 #define rounddown(x, y) (				\
77 {							\
78 	typeof(x) __x = (x);				\
79 	__x - (__x % (y));				\
80 }							\
81 )
82 #define DIV_ROUND_CLOSEST(x, divisor)(			\
83 {							\
84 	typeof(divisor) __divisor = divisor;		\
85 	(((x) + ((__divisor) / 2)) / (__divisor));	\
86 }							\
87 )
88 
89 /*
90  * Multiplies an integer by a fraction, while avoiding unnecessary
91  * overflow or loss of precision.
92  */
93 #define mult_frac(x, numer, denom)(			\
94 {							\
95 	typeof(x) quot = (x) / (denom);			\
96 	typeof(x) rem  = (x) % (denom);			\
97 	(quot * (numer)) + ((rem * (numer)) / (denom));	\
98 }							\
99 )
100 
101 
102 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
103 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
104 
105 #ifdef CONFIG_LBDAF
106 # include <asm/div64.h>
107 # define sector_div(a, b) do_div(a, b)
108 #else
109 # define sector_div(n, b)( \
110 { \
111 	int _res; \
112 	_res = (n) % (b); \
113 	(n) /= (b); \
114 	_res; \
115 } \
116 )
117 #endif
118 
119 /**
120  * upper_32_bits - return bits 32-63 of a number
121  * @n: the number we're accessing
122  *
123  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
124  * the "right shift count >= width of type" warning when that quantity is
125  * 32-bits.
126  */
127 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
128 
129 /**
130  * lower_32_bits - return bits 0-31 of a number
131  * @n: the number we're accessing
132  */
133 #define lower_32_bits(n) ((u32)(n))
134 
135 struct completion;
136 struct pt_regs;
137 struct user;
138 
139 #ifdef CONFIG_PREEMPT_VOLUNTARY
140 extern int _cond_resched(void);
141 # define might_resched() _cond_resched()
142 #else
143 # define might_resched() do { } while (0)
144 #endif
145 
146 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
147   void __might_sleep(const char *file, int line, int preempt_offset);
148 /**
149  * might_sleep - annotation for functions that can sleep
150  *
151  * this macro will print a stack trace if it is executed in an atomic
152  * context (spinlock, irq-handler, ...).
153  *
154  * This is a useful debugging help to be able to catch problems early and not
155  * be bitten later when the calling function happens to sleep when it is not
156  * supposed to.
157  */
158 # define might_sleep() \
159 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
160 #else
__might_sleep(const char * file,int line,int preempt_offset)161   static inline void __might_sleep(const char *file, int line,
162 				   int preempt_offset) { }
163 # define might_sleep() do { might_resched(); } while (0)
164 #endif
165 
166 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
167 
168 /*
169  * abs() handles unsigned and signed longs, ints, shorts and chars.  For all
170  * input types abs() returns a signed long.
171  * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
172  * for those.
173  */
174 #define abs(x) ({						\
175 		long ret;					\
176 		if (sizeof(x) == sizeof(long)) {		\
177 			long __x = (x);				\
178 			ret = (__x < 0) ? -__x : __x;		\
179 		} else {					\
180 			int __x = (x);				\
181 			ret = (__x < 0) ? -__x : __x;		\
182 		}						\
183 		ret;						\
184 	})
185 
186 #define abs64(x) ({				\
187 		s64 __x = (x);			\
188 		(__x < 0) ? -__x : __x;		\
189 	})
190 
191 #ifdef CONFIG_PROVE_LOCKING
192 void might_fault(void);
193 #else
might_fault(void)194 static inline void might_fault(void)
195 {
196 	might_sleep();
197 }
198 #endif
199 
200 extern struct atomic_notifier_head panic_notifier_list;
201 extern long (*panic_blink)(int state);
202 __printf(1, 2)
203 void panic(const char *fmt, ...)
204 	__noreturn __cold;
205 extern void oops_enter(void);
206 extern void oops_exit(void);
207 void print_oops_end_marker(void);
208 extern int oops_may_print(void);
209 void do_exit(long error_code)
210 	__noreturn;
211 void complete_and_exit(struct completion *, long)
212 	__noreturn;
213 
214 /* Internal, do not use. */
215 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
216 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
217 
218 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
219 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
kstrtoul(const char * s,unsigned int base,unsigned long * res)220 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
221 {
222 	/*
223 	 * We want to shortcut function call, but
224 	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
225 	 */
226 	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
227 	    __alignof__(unsigned long) == __alignof__(unsigned long long))
228 		return kstrtoull(s, base, (unsigned long long *)res);
229 	else
230 		return _kstrtoul(s, base, res);
231 }
232 
kstrtol(const char * s,unsigned int base,long * res)233 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
234 {
235 	/*
236 	 * We want to shortcut function call, but
237 	 * __builtin_types_compatible_p(long, long long) = 0.
238 	 */
239 	if (sizeof(long) == sizeof(long long) &&
240 	    __alignof__(long) == __alignof__(long long))
241 		return kstrtoll(s, base, (long long *)res);
242 	else
243 		return _kstrtol(s, base, res);
244 }
245 
246 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
247 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
248 
kstrtou64(const char * s,unsigned int base,u64 * res)249 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
250 {
251 	return kstrtoull(s, base, res);
252 }
253 
kstrtos64(const char * s,unsigned int base,s64 * res)254 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
255 {
256 	return kstrtoll(s, base, res);
257 }
258 
kstrtou32(const char * s,unsigned int base,u32 * res)259 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
260 {
261 	return kstrtouint(s, base, res);
262 }
263 
kstrtos32(const char * s,unsigned int base,s32 * res)264 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
265 {
266 	return kstrtoint(s, base, res);
267 }
268 
269 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
270 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
271 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
272 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
273 
274 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
275 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
276 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
277 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
278 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
279 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
280 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
281 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
282 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
283 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
284 
kstrtou64_from_user(const char __user * s,size_t count,unsigned int base,u64 * res)285 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
286 {
287 	return kstrtoull_from_user(s, count, base, res);
288 }
289 
kstrtos64_from_user(const char __user * s,size_t count,unsigned int base,s64 * res)290 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
291 {
292 	return kstrtoll_from_user(s, count, base, res);
293 }
294 
kstrtou32_from_user(const char __user * s,size_t count,unsigned int base,u32 * res)295 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
296 {
297 	return kstrtouint_from_user(s, count, base, res);
298 }
299 
kstrtos32_from_user(const char __user * s,size_t count,unsigned int base,s32 * res)300 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
301 {
302 	return kstrtoint_from_user(s, count, base, res);
303 }
304 
305 /* Obsolete, do not use.  Use kstrto<foo> instead */
306 
307 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
308 extern long simple_strtol(const char *,char **,unsigned int);
309 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
310 extern long long simple_strtoll(const char *,char **,unsigned int);
311 #define strict_strtoul	kstrtoul
312 #define strict_strtol	kstrtol
313 #define strict_strtoull	kstrtoull
314 #define strict_strtoll	kstrtoll
315 
316 extern int num_to_str(char *buf, int size, unsigned long long num);
317 
318 /* lib/printf utilities */
319 
320 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
321 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
322 extern __printf(3, 4)
323 int snprintf(char *buf, size_t size, const char *fmt, ...);
324 extern __printf(3, 0)
325 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
326 extern __printf(3, 4)
327 int scnprintf(char *buf, size_t size, const char *fmt, ...);
328 extern __printf(3, 0)
329 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
330 extern __printf(2, 3)
331 char *kasprintf(gfp_t gfp, const char *fmt, ...);
332 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
333 
334 extern __scanf(2, 3)
335 int sscanf(const char *, const char *, ...);
336 extern __scanf(2, 0)
337 int vsscanf(const char *, const char *, va_list);
338 
339 extern int get_option(char **str, int *pint);
340 extern char *get_options(const char *str, int nints, int *ints);
341 extern unsigned long long memparse(const char *ptr, char **retptr);
342 
343 extern int core_kernel_text(unsigned long addr);
344 extern int core_kernel_data(unsigned long addr);
345 extern int __kernel_text_address(unsigned long addr);
346 extern int kernel_text_address(unsigned long addr);
347 extern int func_ptr_is_kernel_text(void *ptr);
348 
349 struct pid;
350 extern struct pid *session_of_pgrp(struct pid *pgrp);
351 
352 unsigned long int_sqrt(unsigned long);
353 
354 extern void bust_spinlocks(int yes);
355 extern void wake_up_klogd(void);
356 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
357 extern int panic_timeout;
358 extern int panic_on_oops;
359 extern int panic_on_unrecovered_nmi;
360 extern int panic_on_io_nmi;
361 extern int sysctl_panic_on_stackoverflow;
362 extern const char *print_tainted(void);
363 extern void add_taint(unsigned flag);
364 extern int test_taint(unsigned flag);
365 extern unsigned long get_taint(void);
366 extern int root_mountflags;
367 
368 extern bool early_boot_irqs_disabled;
369 
370 /* Values used for system_state */
371 extern enum system_states {
372 	SYSTEM_BOOTING,
373 	SYSTEM_RUNNING,
374 	SYSTEM_HALT,
375 	SYSTEM_POWER_OFF,
376 	SYSTEM_RESTART,
377 	SYSTEM_SUSPEND_DISK,
378 } system_state;
379 
380 #define TAINT_PROPRIETARY_MODULE	0
381 #define TAINT_FORCED_MODULE		1
382 #define TAINT_UNSAFE_SMP		2
383 #define TAINT_FORCED_RMMOD		3
384 #define TAINT_MACHINE_CHECK		4
385 #define TAINT_BAD_PAGE			5
386 #define TAINT_USER			6
387 #define TAINT_DIE			7
388 #define TAINT_OVERRIDDEN_ACPI_TABLE	8
389 #define TAINT_WARN			9
390 #define TAINT_CRAP			10
391 #define TAINT_FIRMWARE_WORKAROUND	11
392 #define TAINT_OOT_MODULE		12
393 
394 extern const char hex_asc[];
395 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
396 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
397 
hex_byte_pack(char * buf,u8 byte)398 static inline char *hex_byte_pack(char *buf, u8 byte)
399 {
400 	*buf++ = hex_asc_hi(byte);
401 	*buf++ = hex_asc_lo(byte);
402 	return buf;
403 }
404 
pack_hex_byte(char * buf,u8 byte)405 static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
406 {
407 	return hex_byte_pack(buf, byte);
408 }
409 
410 extern int hex_to_bin(char ch);
411 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
412 
413 /*
414  * General tracing related utility functions - trace_printk(),
415  * tracing_on/tracing_off and tracing_start()/tracing_stop
416  *
417  * Use tracing_on/tracing_off when you want to quickly turn on or off
418  * tracing. It simply enables or disables the recording of the trace events.
419  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
420  * file, which gives a means for the kernel and userspace to interact.
421  * Place a tracing_off() in the kernel where you want tracing to end.
422  * From user space, examine the trace, and then echo 1 > tracing_on
423  * to continue tracing.
424  *
425  * tracing_stop/tracing_start has slightly more overhead. It is used
426  * by things like suspend to ram where disabling the recording of the
427  * trace is not enough, but tracing must actually stop because things
428  * like calling smp_processor_id() may crash the system.
429  *
430  * Most likely, you want to use tracing_on/tracing_off.
431  */
432 #ifdef CONFIG_RING_BUFFER
433 /* trace_off_permanent stops recording with no way to bring it back */
434 void tracing_off_permanent(void);
435 #else
tracing_off_permanent(void)436 static inline void tracing_off_permanent(void) { }
437 #endif
438 
439 enum ftrace_dump_mode {
440 	DUMP_NONE,
441 	DUMP_ALL,
442 	DUMP_ORIG,
443 };
444 
445 #ifdef CONFIG_TRACING
446 void tracing_on(void);
447 void tracing_off(void);
448 int tracing_is_on(void);
449 
450 extern void tracing_start(void);
451 extern void tracing_stop(void);
452 extern void ftrace_off_permanent(void);
453 
454 static inline __printf(1, 2)
____trace_printk_check_format(const char * fmt,...)455 void ____trace_printk_check_format(const char *fmt, ...)
456 {
457 }
458 #define __trace_printk_check_format(fmt, args...)			\
459 do {									\
460 	if (0)								\
461 		____trace_printk_check_format(fmt, ##args);		\
462 } while (0)
463 
464 /**
465  * trace_printk - printf formatting in the ftrace buffer
466  * @fmt: the printf format for printing
467  *
468  * Note: __trace_printk is an internal function for trace_printk and
469  *       the @ip is passed in via the trace_printk macro.
470  *
471  * This function allows a kernel developer to debug fast path sections
472  * that printk is not appropriate for. By scattering in various
473  * printk like tracing in the code, a developer can quickly see
474  * where problems are occurring.
475  *
476  * This is intended as a debugging tool for the developer only.
477  * Please refrain from leaving trace_printks scattered around in
478  * your code.
479  */
480 
481 #define trace_printk(fmt, args...)					\
482 do {									\
483 	__trace_printk_check_format(fmt, ##args);			\
484 	if (__builtin_constant_p(fmt)) {				\
485 		static const char *trace_printk_fmt			\
486 		  __attribute__((section("__trace_printk_fmt"))) =	\
487 			__builtin_constant_p(fmt) ? fmt : NULL;		\
488 									\
489 		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
490 	} else								\
491 		__trace_printk(_THIS_IP_, fmt, ##args);		\
492 } while (0)
493 
494 extern __printf(2, 3)
495 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
496 
497 extern __printf(2, 3)
498 int __trace_printk(unsigned long ip, const char *fmt, ...);
499 
500 extern void trace_dump_stack(void);
501 
502 /*
503  * The double __builtin_constant_p is because gcc will give us an error
504  * if we try to allocate the static variable to fmt if it is not a
505  * constant. Even with the outer if statement.
506  */
507 #define ftrace_vprintk(fmt, vargs)					\
508 do {									\
509 	if (__builtin_constant_p(fmt)) {				\
510 		static const char *trace_printk_fmt			\
511 		  __attribute__((section("__trace_printk_fmt"))) =	\
512 			__builtin_constant_p(fmt) ? fmt : NULL;		\
513 									\
514 		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
515 	} else								\
516 		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
517 } while (0)
518 
519 extern int
520 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
521 
522 extern int
523 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
524 
525 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526 #else
527 static inline __printf(1, 2)
528 int trace_printk(const char *fmt, ...);
529 
tracing_start(void)530 static inline void tracing_start(void) { }
tracing_stop(void)531 static inline void tracing_stop(void) { }
ftrace_off_permanent(void)532 static inline void ftrace_off_permanent(void) { }
trace_dump_stack(void)533 static inline void trace_dump_stack(void) { }
534 
tracing_on(void)535 static inline void tracing_on(void) { }
tracing_off(void)536 static inline void tracing_off(void) { }
tracing_is_on(void)537 static inline int tracing_is_on(void) { return 0; }
538 
539 static inline int
trace_printk(const char * fmt,...)540 trace_printk(const char *fmt, ...)
541 {
542 	return 0;
543 }
544 static inline int
ftrace_vprintk(const char * fmt,va_list ap)545 ftrace_vprintk(const char *fmt, va_list ap)
546 {
547 	return 0;
548 }
ftrace_dump(enum ftrace_dump_mode oops_dump_mode)549 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
550 #endif /* CONFIG_TRACING */
551 
552 /*
553  * min()/max()/clamp() macros that also do
554  * strict type-checking.. See the
555  * "unnecessary" pointer comparison.
556  */
557 #define min(x, y) ({				\
558 	typeof(x) _min1 = (x);			\
559 	typeof(y) _min2 = (y);			\
560 	(void) (&_min1 == &_min2);		\
561 	_min1 < _min2 ? _min1 : _min2; })
562 
563 #define max(x, y) ({				\
564 	typeof(x) _max1 = (x);			\
565 	typeof(y) _max2 = (y);			\
566 	(void) (&_max1 == &_max2);		\
567 	_max1 > _max2 ? _max1 : _max2; })
568 
569 #define min3(x, y, z) ({			\
570 	typeof(x) _min1 = (x);			\
571 	typeof(y) _min2 = (y);			\
572 	typeof(z) _min3 = (z);			\
573 	(void) (&_min1 == &_min2);		\
574 	(void) (&_min1 == &_min3);		\
575 	_min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
576 		(_min2 < _min3 ? _min2 : _min3); })
577 
578 #define max3(x, y, z) ({			\
579 	typeof(x) _max1 = (x);			\
580 	typeof(y) _max2 = (y);			\
581 	typeof(z) _max3 = (z);			\
582 	(void) (&_max1 == &_max2);		\
583 	(void) (&_max1 == &_max3);		\
584 	_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
585 		(_max2 > _max3 ? _max2 : _max3); })
586 
587 /**
588  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
589  * @x: value1
590  * @y: value2
591  */
592 #define min_not_zero(x, y) ({			\
593 	typeof(x) __x = (x);			\
594 	typeof(y) __y = (y);			\
595 	__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
596 
597 /**
598  * clamp - return a value clamped to a given range with strict typechecking
599  * @val: current value
600  * @min: minimum allowable value
601  * @max: maximum allowable value
602  *
603  * This macro does strict typechecking of min/max to make sure they are of the
604  * same type as val.  See the unnecessary pointer comparisons.
605  */
606 #define clamp(val, min, max) ({			\
607 	typeof(val) __val = (val);		\
608 	typeof(min) __min = (min);		\
609 	typeof(max) __max = (max);		\
610 	(void) (&__val == &__min);		\
611 	(void) (&__val == &__max);		\
612 	__val = __val < __min ? __min: __val;	\
613 	__val > __max ? __max: __val; })
614 
615 /*
616  * ..and if you can't take the strict
617  * types, you can specify one yourself.
618  *
619  * Or not use min/max/clamp at all, of course.
620  */
621 #define min_t(type, x, y) ({			\
622 	type __min1 = (x);			\
623 	type __min2 = (y);			\
624 	__min1 < __min2 ? __min1: __min2; })
625 
626 #define max_t(type, x, y) ({			\
627 	type __max1 = (x);			\
628 	type __max2 = (y);			\
629 	__max1 > __max2 ? __max1: __max2; })
630 
631 /**
632  * clamp_t - return a value clamped to a given range using a given type
633  * @type: the type of variable to use
634  * @val: current value
635  * @min: minimum allowable value
636  * @max: maximum allowable value
637  *
638  * This macro does no typechecking and uses temporary variables of type
639  * 'type' to make all the comparisons.
640  */
641 #define clamp_t(type, val, min, max) ({		\
642 	type __val = (val);			\
643 	type __min = (min);			\
644 	type __max = (max);			\
645 	__val = __val < __min ? __min: __val;	\
646 	__val > __max ? __max: __val; })
647 
648 /**
649  * clamp_val - return a value clamped to a given range using val's type
650  * @val: current value
651  * @min: minimum allowable value
652  * @max: maximum allowable value
653  *
654  * This macro does no typechecking and uses temporary variables of whatever
655  * type the input argument 'val' is.  This is useful when val is an unsigned
656  * type and min and max are literals that will otherwise be assigned a signed
657  * integer type.
658  */
659 #define clamp_val(val, min, max) ({		\
660 	typeof(val) __val = (val);		\
661 	typeof(val) __min = (min);		\
662 	typeof(val) __max = (max);		\
663 	__val = __val < __min ? __min: __val;	\
664 	__val > __max ? __max: __val; })
665 
666 
667 /*
668  * swap - swap value of @a and @b
669  */
670 #define swap(a, b) \
671 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
672 
673 /**
674  * container_of - cast a member of a structure out to the containing structure
675  * @ptr:	the pointer to the member.
676  * @type:	the type of the container struct this is embedded in.
677  * @member:	the name of the member within the struct.
678  *
679  */
680 #define container_of(ptr, type, member) ({			\
681 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
682 	(type *)( (char *)__mptr - offsetof(type,member) );})
683 
684 /* Trap pasters of __FUNCTION__ at compile-time */
685 #define __FUNCTION__ (__func__)
686 
687 /* This helps us to avoid #ifdef CONFIG_NUMA */
688 #ifdef CONFIG_NUMA
689 #define NUMA_BUILD 1
690 #else
691 #define NUMA_BUILD 0
692 #endif
693 
694 /* This helps us avoid #ifdef CONFIG_COMPACTION */
695 #ifdef CONFIG_COMPACTION
696 #define COMPACTION_BUILD 1
697 #else
698 #define COMPACTION_BUILD 0
699 #endif
700 
701 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
702 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
703 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
704 #endif
705 
706 extern int do_sysinfo(struct sysinfo *info);
707 
708 #endif /* __KERNEL__ */
709 
710 #endif
711