1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 /*
5  * 'kernel.h' contains some often-used function prototypes etc
6  */
7 #define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
8 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
9 
10 #ifdef __KERNEL__
11 
12 #include <stdarg.h>
13 #include <linux/linkage.h>
14 #include <linux/stddef.h>
15 #include <linux/types.h>
16 #include <linux/compiler.h>
17 #include <linux/bitops.h>
18 #include <linux/log2.h>
19 #include <linux/typecheck.h>
20 #include <linux/printk.h>
21 #include <linux/dynamic_debug.h>
22 #include <asm/byteorder.h>
23 #include <asm/bug.h>
24 
25 #define USHRT_MAX	((u16)(~0U))
26 #define SHRT_MAX	((s16)(USHRT_MAX>>1))
27 #define SHRT_MIN	((s16)(-SHRT_MAX - 1))
28 #define INT_MAX		((int)(~0U>>1))
29 #define INT_MIN		(-INT_MAX - 1)
30 #define UINT_MAX	(~0U)
31 #define LONG_MAX	((long)(~0UL>>1))
32 #define LONG_MIN	(-LONG_MAX - 1)
33 #define ULONG_MAX	(~0UL)
34 #define LLONG_MAX	((long long)(~0ULL>>1))
35 #define LLONG_MIN	(-LLONG_MAX - 1)
36 #define ULLONG_MAX	(~0ULL)
37 
38 #define STACK_MAGIC	0xdeadbeef
39 
40 #define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
41 #define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
42 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
43 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
44 
45 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
46 
47 /*
48  * This looks more complex than it should be. But we need to
49  * get the type for the ~ right in round_down (it needs to be
50  * as wide as the result!), and we want to evaluate the macro
51  * arguments just once each.
52  */
53 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
54 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
55 #define round_down(x, y) ((x) & ~__round_mask(x, y))
56 
57 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
58 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
59 
60 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
61 #define roundup(x, y) (					\
62 {							\
63 	const typeof(y) __y = y;			\
64 	(((x) + (__y - 1)) / __y) * __y;		\
65 }							\
66 )
67 #define rounddown(x, y) (				\
68 {							\
69 	typeof(x) __x = (x);				\
70 	__x - (__x % (y));				\
71 }							\
72 )
73 #define DIV_ROUND_CLOSEST(x, divisor)(			\
74 {							\
75 	typeof(divisor) __divisor = divisor;		\
76 	(((x) + ((__divisor) / 2)) / (__divisor));	\
77 }							\
78 )
79 
80 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
81 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
82 
83 #ifdef CONFIG_LBDAF
84 # include <asm/div64.h>
85 # define sector_div(a, b) do_div(a, b)
86 #else
87 # define sector_div(n, b)( \
88 { \
89 	int _res; \
90 	_res = (n) % (b); \
91 	(n) /= (b); \
92 	_res; \
93 } \
94 )
95 #endif
96 
97 /**
98  * upper_32_bits - return bits 32-63 of a number
99  * @n: the number we're accessing
100  *
101  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
102  * the "right shift count >= width of type" warning when that quantity is
103  * 32-bits.
104  */
105 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
106 
107 /**
108  * lower_32_bits - return bits 0-31 of a number
109  * @n: the number we're accessing
110  */
111 #define lower_32_bits(n) ((u32)(n))
112 
113 struct completion;
114 struct pt_regs;
115 struct user;
116 
117 #ifdef CONFIG_PREEMPT_VOLUNTARY
118 extern int _cond_resched(void);
119 # define might_resched() _cond_resched()
120 #else
121 # define might_resched() do { } while (0)
122 #endif
123 
124 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
125   void __might_sleep(const char *file, int line, int preempt_offset);
126 /**
127  * might_sleep - annotation for functions that can sleep
128  *
129  * this macro will print a stack trace if it is executed in an atomic
130  * context (spinlock, irq-handler, ...).
131  *
132  * This is a useful debugging help to be able to catch problems early and not
133  * be bitten later when the calling function happens to sleep when it is not
134  * supposed to.
135  */
136 # define might_sleep() \
137 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
138 #else
__might_sleep(const char * file,int line,int preempt_offset)139   static inline void __might_sleep(const char *file, int line,
140 				   int preempt_offset) { }
141 # define might_sleep() do { might_resched(); } while (0)
142 #endif
143 
144 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
145 
146 /*
147  * abs() handles unsigned and signed longs, ints, shorts and chars.  For all
148  * input types abs() returns a signed long.
149  * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
150  * for those.
151  */
152 #define abs(x) ({						\
153 		long ret;					\
154 		if (sizeof(x) == sizeof(long)) {		\
155 			long __x = (x);				\
156 			ret = (__x < 0) ? -__x : __x;		\
157 		} else {					\
158 			int __x = (x);				\
159 			ret = (__x < 0) ? -__x : __x;		\
160 		}						\
161 		ret;						\
162 	})
163 
164 #define abs64(x) ({				\
165 		s64 __x = (x);			\
166 		(__x < 0) ? -__x : __x;		\
167 	})
168 
169 #ifdef CONFIG_PROVE_LOCKING
170 void might_fault(void);
171 #else
might_fault(void)172 static inline void might_fault(void)
173 {
174 	might_sleep();
175 }
176 #endif
177 
178 extern struct atomic_notifier_head panic_notifier_list;
179 extern long (*panic_blink)(int state);
180 NORET_TYPE void panic(const char * fmt, ...)
181 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
182 extern void oops_enter(void);
183 extern void oops_exit(void);
184 void print_oops_end_marker(void);
185 extern int oops_may_print(void);
186 NORET_TYPE void do_exit(long error_code)
187 	ATTRIB_NORET;
188 NORET_TYPE void complete_and_exit(struct completion *, long)
189 	ATTRIB_NORET;
190 
191 /* Internal, do not use. */
192 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
193 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
194 
195 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
196 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
kstrtoul(const char * s,unsigned int base,unsigned long * res)197 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
198 {
199 	/*
200 	 * We want to shortcut function call, but
201 	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
202 	 */
203 	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
204 	    __alignof__(unsigned long) == __alignof__(unsigned long long))
205 		return kstrtoull(s, base, (unsigned long long *)res);
206 	else
207 		return _kstrtoul(s, base, res);
208 }
209 
kstrtol(const char * s,unsigned int base,long * res)210 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
211 {
212 	/*
213 	 * We want to shortcut function call, but
214 	 * __builtin_types_compatible_p(long, long long) = 0.
215 	 */
216 	if (sizeof(long) == sizeof(long long) &&
217 	    __alignof__(long) == __alignof__(long long))
218 		return kstrtoll(s, base, (long long *)res);
219 	else
220 		return _kstrtol(s, base, res);
221 }
222 
223 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
224 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
225 
kstrtou64(const char * s,unsigned int base,u64 * res)226 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
227 {
228 	return kstrtoull(s, base, res);
229 }
230 
kstrtos64(const char * s,unsigned int base,s64 * res)231 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
232 {
233 	return kstrtoll(s, base, res);
234 }
235 
kstrtou32(const char * s,unsigned int base,u32 * res)236 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
237 {
238 	return kstrtouint(s, base, res);
239 }
240 
kstrtos32(const char * s,unsigned int base,s32 * res)241 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
242 {
243 	return kstrtoint(s, base, res);
244 }
245 
246 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
247 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
248 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
249 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
250 
251 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
252 extern long simple_strtol(const char *,char **,unsigned int);
253 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
254 extern long long simple_strtoll(const char *,char **,unsigned int);
255 #define strict_strtoul	kstrtoul
256 #define strict_strtol	kstrtol
257 #define strict_strtoull	kstrtoull
258 #define strict_strtoll	kstrtoll
259 
260 extern int sprintf(char * buf, const char * fmt, ...)
261 	__attribute__ ((format (printf, 2, 3)));
262 extern int vsprintf(char *buf, const char *, va_list)
263 	__attribute__ ((format (printf, 2, 0)));
264 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
265 	__attribute__ ((format (printf, 3, 4)));
266 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
267 	__attribute__ ((format (printf, 3, 0)));
268 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
269 	__attribute__ ((format (printf, 3, 4)));
270 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
271 	__attribute__ ((format (printf, 3, 0)));
272 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
273 	__attribute__ ((format (printf, 2, 3)));
274 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
275 
276 extern int sscanf(const char *, const char *, ...)
277 	__attribute__ ((format (scanf, 2, 3)));
278 extern int vsscanf(const char *, const char *, va_list)
279 	__attribute__ ((format (scanf, 2, 0)));
280 
281 extern int get_option(char **str, int *pint);
282 extern char *get_options(const char *str, int nints, int *ints);
283 extern unsigned long long memparse(const char *ptr, char **retptr);
284 
285 extern int core_kernel_text(unsigned long addr);
286 extern int __kernel_text_address(unsigned long addr);
287 extern int kernel_text_address(unsigned long addr);
288 extern int func_ptr_is_kernel_text(void *ptr);
289 
290 struct pid;
291 extern struct pid *session_of_pgrp(struct pid *pgrp);
292 
293 unsigned long int_sqrt(unsigned long);
294 
295 extern void bust_spinlocks(int yes);
296 extern void wake_up_klogd(void);
297 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
298 extern int panic_timeout;
299 extern int panic_on_oops;
300 extern int panic_on_unrecovered_nmi;
301 extern int panic_on_io_nmi;
302 extern const char *print_tainted(void);
303 extern void add_taint(unsigned flag);
304 extern int test_taint(unsigned flag);
305 extern unsigned long get_taint(void);
306 extern int root_mountflags;
307 
308 extern bool early_boot_irqs_disabled;
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 #define TAINT_FIRMWARE_WORKAROUND	11
332 
333 extern const char hex_asc[];
334 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
335 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
336 
pack_hex_byte(char * buf,u8 byte)337 static inline char *pack_hex_byte(char *buf, u8 byte)
338 {
339 	*buf++ = hex_asc_hi(byte);
340 	*buf++ = hex_asc_lo(byte);
341 	return buf;
342 }
343 
344 extern int hex_to_bin(char ch);
345 extern void hex2bin(u8 *dst, const char *src, size_t count);
346 
347 /*
348  * General tracing related utility functions - trace_printk(),
349  * tracing_on/tracing_off and tracing_start()/tracing_stop
350  *
351  * Use tracing_on/tracing_off when you want to quickly turn on or off
352  * tracing. It simply enables or disables the recording of the trace events.
353  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
354  * file, which gives a means for the kernel and userspace to interact.
355  * Place a tracing_off() in the kernel where you want tracing to end.
356  * From user space, examine the trace, and then echo 1 > tracing_on
357  * to continue tracing.
358  *
359  * tracing_stop/tracing_start has slightly more overhead. It is used
360  * by things like suspend to ram where disabling the recording of the
361  * trace is not enough, but tracing must actually stop because things
362  * like calling smp_processor_id() may crash the system.
363  *
364  * Most likely, you want to use tracing_on/tracing_off.
365  */
366 #ifdef CONFIG_RING_BUFFER
367 void tracing_on(void);
368 void tracing_off(void);
369 /* trace_off_permanent stops recording with no way to bring it back */
370 void tracing_off_permanent(void);
371 int tracing_is_on(void);
372 #else
tracing_on(void)373 static inline void tracing_on(void) { }
tracing_off(void)374 static inline void tracing_off(void) { }
tracing_off_permanent(void)375 static inline void tracing_off_permanent(void) { }
tracing_is_on(void)376 static inline int tracing_is_on(void) { return 0; }
377 #endif
378 
379 enum ftrace_dump_mode {
380 	DUMP_NONE,
381 	DUMP_ALL,
382 	DUMP_ORIG,
383 };
384 
385 #ifdef CONFIG_TRACING
386 extern void tracing_start(void);
387 extern void tracing_stop(void);
388 extern void ftrace_off_permanent(void);
389 
390 static inline void __attribute__ ((format (printf, 1, 2)))
____trace_printk_check_format(const char * fmt,...)391 ____trace_printk_check_format(const char *fmt, ...)
392 {
393 }
394 #define __trace_printk_check_format(fmt, args...)			\
395 do {									\
396 	if (0)								\
397 		____trace_printk_check_format(fmt, ##args);		\
398 } while (0)
399 
400 /**
401  * trace_printk - printf formatting in the ftrace buffer
402  * @fmt: the printf format for printing
403  *
404  * Note: __trace_printk is an internal function for trace_printk and
405  *       the @ip is passed in via the trace_printk macro.
406  *
407  * This function allows a kernel developer to debug fast path sections
408  * that printk is not appropriate for. By scattering in various
409  * printk like tracing in the code, a developer can quickly see
410  * where problems are occurring.
411  *
412  * This is intended as a debugging tool for the developer only.
413  * Please refrain from leaving trace_printks scattered around in
414  * your code.
415  */
416 
417 #define trace_printk(fmt, args...)					\
418 do {									\
419 	__trace_printk_check_format(fmt, ##args);			\
420 	if (__builtin_constant_p(fmt)) {				\
421 		static const char *trace_printk_fmt			\
422 		  __attribute__((section("__trace_printk_fmt"))) =	\
423 			__builtin_constant_p(fmt) ? fmt : NULL;		\
424 									\
425 		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
426 	} else								\
427 		__trace_printk(_THIS_IP_, fmt, ##args);		\
428 } while (0)
429 
430 extern int
431 __trace_bprintk(unsigned long ip, const char *fmt, ...)
432 	__attribute__ ((format (printf, 2, 3)));
433 
434 extern int
435 __trace_printk(unsigned long ip, const char *fmt, ...)
436 	__attribute__ ((format (printf, 2, 3)));
437 
438 extern void trace_dump_stack(void);
439 
440 /*
441  * The double __builtin_constant_p is because gcc will give us an error
442  * if we try to allocate the static variable to fmt if it is not a
443  * constant. Even with the outer if statement.
444  */
445 #define ftrace_vprintk(fmt, vargs)					\
446 do {									\
447 	if (__builtin_constant_p(fmt)) {				\
448 		static const char *trace_printk_fmt			\
449 		  __attribute__((section("__trace_printk_fmt"))) =	\
450 			__builtin_constant_p(fmt) ? fmt : NULL;		\
451 									\
452 		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
453 	} else								\
454 		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
455 } while (0)
456 
457 extern int
458 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
459 
460 extern int
461 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
462 
463 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
464 #else
465 static inline int
466 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
467 
tracing_start(void)468 static inline void tracing_start(void) { }
tracing_stop(void)469 static inline void tracing_stop(void) { }
ftrace_off_permanent(void)470 static inline void ftrace_off_permanent(void) { }
trace_dump_stack(void)471 static inline void trace_dump_stack(void) { }
472 static inline int
trace_printk(const char * fmt,...)473 trace_printk(const char *fmt, ...)
474 {
475 	return 0;
476 }
477 static inline int
ftrace_vprintk(const char * fmt,va_list ap)478 ftrace_vprintk(const char *fmt, va_list ap)
479 {
480 	return 0;
481 }
ftrace_dump(enum ftrace_dump_mode oops_dump_mode)482 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
483 #endif /* CONFIG_TRACING */
484 
485 /*
486  * min()/max()/clamp() macros that also do
487  * strict type-checking.. See the
488  * "unnecessary" pointer comparison.
489  */
490 #define min(x, y) ({				\
491 	typeof(x) _min1 = (x);			\
492 	typeof(y) _min2 = (y);			\
493 	(void) (&_min1 == &_min2);		\
494 	_min1 < _min2 ? _min1 : _min2; })
495 
496 #define max(x, y) ({				\
497 	typeof(x) _max1 = (x);			\
498 	typeof(y) _max2 = (y);			\
499 	(void) (&_max1 == &_max2);		\
500 	_max1 > _max2 ? _max1 : _max2; })
501 
502 #define min3(x, y, z) ({			\
503 	typeof(x) _min1 = (x);			\
504 	typeof(y) _min2 = (y);			\
505 	typeof(z) _min3 = (z);			\
506 	(void) (&_min1 == &_min2);		\
507 	(void) (&_min1 == &_min3);		\
508 	_min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
509 		(_min2 < _min3 ? _min2 : _min3); })
510 
511 #define max3(x, y, z) ({			\
512 	typeof(x) _max1 = (x);			\
513 	typeof(y) _max2 = (y);			\
514 	typeof(z) _max3 = (z);			\
515 	(void) (&_max1 == &_max2);		\
516 	(void) (&_max1 == &_max3);		\
517 	_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
518 		(_max2 > _max3 ? _max2 : _max3); })
519 
520 /**
521  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
522  * @x: value1
523  * @y: value2
524  */
525 #define min_not_zero(x, y) ({			\
526 	typeof(x) __x = (x);			\
527 	typeof(y) __y = (y);			\
528 	__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
529 
530 /**
531  * clamp - return a value clamped to a given range with strict typechecking
532  * @val: current value
533  * @min: minimum allowable value
534  * @max: maximum allowable value
535  *
536  * This macro does strict typechecking of min/max to make sure they are of the
537  * same type as val.  See the unnecessary pointer comparisons.
538  */
539 #define clamp(val, min, max) ({			\
540 	typeof(val) __val = (val);		\
541 	typeof(min) __min = (min);		\
542 	typeof(max) __max = (max);		\
543 	(void) (&__val == &__min);		\
544 	(void) (&__val == &__max);		\
545 	__val = __val < __min ? __min: __val;	\
546 	__val > __max ? __max: __val; })
547 
548 /*
549  * ..and if you can't take the strict
550  * types, you can specify one yourself.
551  *
552  * Or not use min/max/clamp at all, of course.
553  */
554 #define min_t(type, x, y) ({			\
555 	type __min1 = (x);			\
556 	type __min2 = (y);			\
557 	__min1 < __min2 ? __min1: __min2; })
558 
559 #define max_t(type, x, y) ({			\
560 	type __max1 = (x);			\
561 	type __max2 = (y);			\
562 	__max1 > __max2 ? __max1: __max2; })
563 
564 /**
565  * clamp_t - return a value clamped to a given range using a given type
566  * @type: the type of variable to use
567  * @val: current value
568  * @min: minimum allowable value
569  * @max: maximum allowable value
570  *
571  * This macro does no typechecking and uses temporary variables of type
572  * 'type' to make all the comparisons.
573  */
574 #define clamp_t(type, val, min, max) ({		\
575 	type __val = (val);			\
576 	type __min = (min);			\
577 	type __max = (max);			\
578 	__val = __val < __min ? __min: __val;	\
579 	__val > __max ? __max: __val; })
580 
581 /**
582  * clamp_val - return a value clamped to a given range using val's type
583  * @val: current value
584  * @min: minimum allowable value
585  * @max: maximum allowable value
586  *
587  * This macro does no typechecking and uses temporary variables of whatever
588  * type the input argument 'val' is.  This is useful when val is an unsigned
589  * type and min and max are literals that will otherwise be assigned a signed
590  * integer type.
591  */
592 #define clamp_val(val, min, max) ({		\
593 	typeof(val) __val = (val);		\
594 	typeof(val) __min = (min);		\
595 	typeof(val) __max = (max);		\
596 	__val = __val < __min ? __min: __val;	\
597 	__val > __max ? __max: __val; })
598 
599 
600 /*
601  * swap - swap value of @a and @b
602  */
603 #define swap(a, b) \
604 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
605 
606 /**
607  * container_of - cast a member of a structure out to the containing structure
608  * @ptr:	the pointer to the member.
609  * @type:	the type of the container struct this is embedded in.
610  * @member:	the name of the member within the struct.
611  *
612  */
613 #define container_of(ptr, type, member) ({			\
614 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
615 	(type *)( (char *)__mptr - offsetof(type,member) );})
616 
617 struct sysinfo;
618 extern int do_sysinfo(struct sysinfo *info);
619 
620 #endif /* __KERNEL__ */
621 
622 #define SI_LOAD_SHIFT	16
623 struct sysinfo {
624 	long uptime;			/* Seconds since boot */
625 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
626 	unsigned long totalram;		/* Total usable main memory size */
627 	unsigned long freeram;		/* Available memory size */
628 	unsigned long sharedram;	/* Amount of shared memory */
629 	unsigned long bufferram;	/* Memory used by buffers */
630 	unsigned long totalswap;	/* Total swap space size */
631 	unsigned long freeswap;		/* swap space still available */
632 	unsigned short procs;		/* Number of current processes */
633 	unsigned short pad;		/* explicit padding for m68k */
634 	unsigned long totalhigh;	/* Total high memory size */
635 	unsigned long freehigh;		/* Available high memory size */
636 	unsigned int mem_unit;		/* Memory unit size in bytes */
637 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
638 };
639 
640 /* Force a compilation error if a constant expression is not a power of 2 */
641 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
642 	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
643 
644 /* Force a compilation error if condition is true, but also produce a
645    result (of value 0 and type size_t), so the expression can be used
646    e.g. in a structure initializer (or where-ever else comma expressions
647    aren't permitted). */
648 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
649 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
650 
651 /**
652  * BUILD_BUG_ON - break compile if a condition is true.
653  * @condition: the condition which the compiler should know is false.
654  *
655  * If you have some code which relies on certain constants being equal, or
656  * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
657  * detect if someone changes it.
658  *
659  * The implementation uses gcc's reluctance to create a negative array, but
660  * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
661  * to inline functions).  So as a fallback we use the optimizer; if it can't
662  * prove the condition is false, it will cause a link error on the undefined
663  * "__build_bug_on_failed".  This error message can be harder to track down
664  * though, hence the two different methods.
665  */
666 #ifndef __OPTIMIZE__
667 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
668 #else
669 extern int __build_bug_on_failed;
670 #define BUILD_BUG_ON(condition)					\
671 	do {							\
672 		((void)sizeof(char[1 - 2*!!(condition)]));	\
673 		if (condition) __build_bug_on_failed = 1;	\
674 	} while(0)
675 #endif
676 
677 /* Trap pasters of __FUNCTION__ at compile-time */
678 #define __FUNCTION__ (__func__)
679 
680 /* This helps us to avoid #ifdef CONFIG_NUMA */
681 #ifdef CONFIG_NUMA
682 #define NUMA_BUILD 1
683 #else
684 #define NUMA_BUILD 0
685 #endif
686 
687 /* This helps us avoid #ifdef CONFIG_COMPACTION */
688 #ifdef CONFIG_COMPACTION
689 #define COMPACTION_BUILD 1
690 #else
691 #define COMPACTION_BUILD 0
692 #endif
693 
694 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
695 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
696 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
697 #endif
698 
699 #endif
700