tty: make receive_buf() return the amout of bytes received
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / linux / kernel.h
blob00cec4dc0ae25a3cf6ac57bebcc239d145b8d641
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
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))
10 #ifdef __KERNEL__
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>
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)
38 #define STACK_MAGIC 0xdeadbeef
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)
45 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
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.
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))
57 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
58 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
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 } \
67 #define rounddown(x, y) ( \
68 { \
69 typeof(x) __x = (x); \
70 __x - (__x % (y)); \
71 } \
73 #define DIV_ROUND_CLOSEST(x, divisor)( \
74 { \
75 typeof(divisor) __divisor = divisor; \
76 (((x) + ((__divisor) / 2)) / (__divisor)); \
77 } \
80 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
81 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
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 } \
95 #endif
97 /**
98 * upper_32_bits - return bits 32-63 of a number
99 * @n: the number we're accessing
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.
105 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
108 * lower_32_bits - return bits 0-31 of a number
109 * @n: the number we're accessing
111 #define lower_32_bits(n) ((u32)(n))
113 struct completion;
114 struct pt_regs;
115 struct user;
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
124 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
125 void __might_sleep(const char *file, int line, int preempt_offset);
127 * might_sleep - annotation for functions that can sleep
129 * this macro will print a stack trace if it is executed in an atomic
130 * context (spinlock, irq-handler, ...).
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.
136 # define might_sleep() \
137 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
138 #else
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
144 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
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.
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; \
161 ret; \
164 #define abs64(x) ({ \
165 s64 __x = (x); \
166 (__x < 0) ? -__x : __x; \
169 #ifdef CONFIG_PROVE_LOCKING
170 void might_fault(void);
171 #else
172 static inline void might_fault(void)
174 might_sleep();
176 #endif
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;
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);
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);
197 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
200 * We want to shortcut function call, but
201 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
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);
210 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
213 * We want to shortcut function call, but
214 * __builtin_types_compatible_p(long, long long) = 0.
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);
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);
226 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
228 return kstrtoull(s, base, res);
231 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
233 return kstrtoll(s, base, res);
236 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
238 return kstrtouint(s, base, res);
241 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
243 return kstrtoint(s, base, res);
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);
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
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);
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)));
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);
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);
290 struct pid;
291 extern struct pid *session_of_pgrp(struct pid *pgrp);
293 unsigned long int_sqrt(unsigned long);
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;
308 extern bool early_boot_irqs_disabled;
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;
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
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]
337 static inline char *pack_hex_byte(char *buf, u8 byte)
339 *buf++ = hex_asc_hi(byte);
340 *buf++ = hex_asc_lo(byte);
341 return buf;
344 extern int hex_to_bin(char ch);
345 extern void hex2bin(u8 *dst, const char *src, size_t count);
348 * General tracing related utility functions - trace_printk(),
349 * tracing_on/tracing_off and tracing_start()/tracing_stop
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.
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.
364 * Most likely, you want to use tracing_on/tracing_off.
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
373 static inline void tracing_on(void) { }
374 static inline void tracing_off(void) { }
375 static inline void tracing_off_permanent(void) { }
376 static inline int tracing_is_on(void) { return 0; }
377 #endif
379 enum ftrace_dump_mode {
380 DUMP_NONE,
381 DUMP_ALL,
382 DUMP_ORIG,
385 #ifdef CONFIG_TRACING
386 extern void tracing_start(void);
387 extern void tracing_stop(void);
388 extern void ftrace_off_permanent(void);
390 static inline void __attribute__ ((format (printf, 1, 2)))
391 ____trace_printk_check_format(const char *fmt, ...)
394 #define __trace_printk_check_format(fmt, args...) \
395 do { \
396 if (0) \
397 ____trace_printk_check_format(fmt, ##args); \
398 } while (0)
401 * trace_printk - printf formatting in the ftrace buffer
402 * @fmt: the printf format for printing
404 * Note: __trace_printk is an internal function for trace_printk and
405 * the @ip is passed in via the trace_printk macro.
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.
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.
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; \
425 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
426 } else \
427 __trace_printk(_THIS_IP_, fmt, ##args); \
428 } while (0)
430 extern int
431 __trace_bprintk(unsigned long ip, const char *fmt, ...)
432 __attribute__ ((format (printf, 2, 3)));
434 extern int
435 __trace_printk(unsigned long ip, const char *fmt, ...)
436 __attribute__ ((format (printf, 2, 3)));
438 extern void trace_dump_stack(void);
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.
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; \
452 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
453 } else \
454 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
455 } while (0)
457 extern int
458 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
460 extern int
461 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
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)));
468 static inline void tracing_start(void) { }
469 static inline void tracing_stop(void) { }
470 static inline void ftrace_off_permanent(void) { }
471 static inline void trace_dump_stack(void) { }
472 static inline int
473 trace_printk(const char *fmt, ...)
475 return 0;
477 static inline int
478 ftrace_vprintk(const char *fmt, va_list ap)
480 return 0;
482 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
483 #endif /* CONFIG_TRACING */
486 * min()/max()/clamp() macros that also do
487 * strict type-checking.. See the
488 * "unnecessary" pointer comparison.
490 #define min(x, y) ({ \
491 typeof(x) _min1 = (x); \
492 typeof(y) _min2 = (y); \
493 (void) (&_min1 == &_min2); \
494 _min1 < _min2 ? _min1 : _min2; })
496 #define max(x, y) ({ \
497 typeof(x) _max1 = (x); \
498 typeof(y) _max2 = (y); \
499 (void) (&_max1 == &_max2); \
500 _max1 > _max2 ? _max1 : _max2; })
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); })
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); })
521 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
522 * @x: value1
523 * @y: value2
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)); })
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
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.
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; })
549 * ..and if you can't take the strict
550 * types, you can specify one yourself.
552 * Or not use min/max/clamp at all, of course.
554 #define min_t(type, x, y) ({ \
555 type __min1 = (x); \
556 type __min2 = (y); \
557 __min1 < __min2 ? __min1: __min2; })
559 #define max_t(type, x, y) ({ \
560 type __max1 = (x); \
561 type __max2 = (y); \
562 __max1 > __max2 ? __max1: __max2; })
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
571 * This macro does no typechecking and uses temporary variables of type
572 * 'type' to make all the comparisons.
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; })
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
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.
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; })
601 * swap - swap value of @a and @b
603 #define swap(a, b) \
604 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
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.
613 #define container_of(ptr, type, member) ({ \
614 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
615 (type *)( (char *)__mptr - offsetof(type,member) );})
617 struct sysinfo;
618 extern int do_sysinfo(struct sysinfo *info);
620 #endif /* __KERNEL__ */
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.. */
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))
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); }))
652 * BUILD_BUG_ON - break compile if a condition is true.
653 * @condition: the condition which the compiler should know is false.
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.
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.
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
677 /* Trap pasters of __FUNCTION__ at compile-time */
678 #define __FUNCTION__ (__func__)
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
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
694 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
695 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
696 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
697 #endif
699 #endif