Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes
[linux-2.6-block.git] / include / linux / kernel.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
4/*
5 * 'kernel.h' contains some often-used function prototypes etc
6 */
7
8#ifdef __KERNEL__
9
10#include <stdarg.h>
11#include <linux/linkage.h>
12#include <linux/stddef.h>
13#include <linux/types.h>
14#include <linux/compiler.h>
15#include <linux/bitops.h>
f0d1b0b3 16#include <linux/log2.h>
e0deaff4 17#include <linux/typecheck.h>
717115e1 18#include <linux/ratelimit.h>
e9d376f0 19#include <linux/dynamic_debug.h>
1da177e4
LT
20#include <asm/byteorder.h>
21#include <asm/bug.h>
22
3eb3c740
RZ
23extern const char linux_banner[];
24extern const char linux_proc_banner[];
25
44f564a4
ZY
26#define USHORT_MAX ((u16)(~0U))
27#define SHORT_MAX ((s16)(USHORT_MAX>>1))
28#define SHORT_MIN (-SHORT_MAX - 1)
1da177e4
LT
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)
111ebb6e
OH
35#define LLONG_MAX ((long long)(~0ULL>>1))
36#define LLONG_MIN (-LLONG_MAX - 1)
37#define ULLONG_MAX (~0ULL)
1da177e4
LT
38
39#define STACK_MAGIC 0xdeadbeef
40
2ea58144
LT
41#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1)
42#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
a83308e6 43#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 44#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 45
c5e631cf
RR
46#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
47
4552d5dc 48#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 49#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
b4cac1a0 50#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
9fe06081
DW
51#define DIV_ROUND_CLOSEST(x, divisor)( \
52{ \
53 typeof(divisor) __divisor = divisor; \
54 (((x) + ((__divisor) / 2)) / (__divisor)); \
55} \
56)
1da177e4 57
ca31e146
EGM
58#define _RET_IP_ (unsigned long)__builtin_return_address(0)
59#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
60
2da96acd
JA
61#ifdef CONFIG_LBD
62# include <asm/div64.h>
63# define sector_div(a, b) do_div(a, b)
64#else
65# define sector_div(n, b)( \
66{ \
67 int _res; \
68 _res = (n) % (b); \
69 (n) /= (b); \
70 _res; \
71} \
72)
73#endif
74
218e180e
AM
75/**
76 * upper_32_bits - return bits 32-63 of a number
77 * @n: the number we're accessing
78 *
79 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
80 * the "right shift count >= width of type" warning when that quantity is
81 * 32-bits.
82 */
83#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
84
204b885e
JR
85/**
86 * lower_32_bits - return bits 0-31 of a number
87 * @n: the number we're accessing
88 */
89#define lower_32_bits(n) ((u32)(n))
90
1da177e4
LT
91#define KERN_EMERG "<0>" /* system is unusable */
92#define KERN_ALERT "<1>" /* action must be taken immediately */
93#define KERN_CRIT "<2>" /* critical conditions */
94#define KERN_ERR "<3>" /* error conditions */
95#define KERN_WARNING "<4>" /* warning conditions */
96#define KERN_NOTICE "<5>" /* normal but significant condition */
97#define KERN_INFO "<6>" /* informational */
98#define KERN_DEBUG "<7>" /* debug-level messages */
99
47492527
IM
100/*
101 * Annotation for a "continued" line of log printout (only done after a
102 * line that had no enclosing \n). Only to be used by core/arch code
103 * during early bootup (a continued line is not SMP-safe otherwise).
104 */
105#define KERN_CONT ""
106
1da177e4
LT
107extern int console_printk[];
108
109#define console_loglevel (console_printk[0])
110#define default_message_loglevel (console_printk[1])
111#define minimum_console_loglevel (console_printk[2])
112#define default_console_loglevel (console_printk[3])
113
114struct completion;
df2e71fb 115struct pt_regs;
116struct user;
1da177e4 117
070cb065
UKK
118#ifdef CONFIG_PREEMPT_VOLUNTARY
119extern int _cond_resched(void);
120# define might_resched() _cond_resched()
121#else
122# define might_resched() do { } while (0)
123#endif
124
7106a27b
RD
125#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
126 void __might_sleep(char *file, int line);
1da177e4
LT
127/**
128 * might_sleep - annotation for functions that can sleep
129 *
130 * this macro will print a stack trace if it is executed in an atomic
131 * context (spinlock, irq-handler, ...).
132 *
133 * This is a useful debugging help to be able to catch problems early and not
e20ec991 134 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
135 * supposed to.
136 */
f8cbd99b
IM
137# define might_sleep() \
138 do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
1da177e4 139#else
f8cbd99b 140# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
141#endif
142
368a5fa1 143#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 144
1da177e4
LT
145#define abs(x) ({ \
146 int __x = (x); \
147 (__x < 0) ? -__x : __x; \
148 })
149
3ee1afa3
NP
150#ifdef CONFIG_PROVE_LOCKING
151void might_fault(void);
152#else
153static inline void might_fault(void)
154{
155 might_sleep();
156}
157#endif
158
e041c683 159extern struct atomic_notifier_head panic_notifier_list;
1da177e4
LT
160extern long (*panic_blink)(long time);
161NORET_TYPE void panic(const char * fmt, ...)
a586df06 162 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
dd287796
AM
163extern void oops_enter(void);
164extern void oops_exit(void);
165extern int oops_may_print(void);
ec701584 166NORET_TYPE void do_exit(long error_code)
1da177e4
LT
167 ATTRIB_NORET;
168NORET_TYPE void complete_and_exit(struct completion *, long)
169 ATTRIB_NORET;
170extern unsigned long simple_strtoul(const char *,char **,unsigned int);
171extern long simple_strtol(const char *,char **,unsigned int);
172extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
173extern long long simple_strtoll(const char *,char **,unsigned int);
06b2a76d
YY
174extern int strict_strtoul(const char *, unsigned int, unsigned long *);
175extern int strict_strtol(const char *, unsigned int, long *);
176extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
177extern int strict_strtoll(const char *, unsigned int, long long *);
1da177e4
LT
178extern int sprintf(char * buf, const char * fmt, ...)
179 __attribute__ ((format (printf, 2, 3)));
180extern int vsprintf(char *buf, const char *, va_list)
181 __attribute__ ((format (printf, 2, 0)));
182extern int snprintf(char * buf, size_t size, const char * fmt, ...)
183 __attribute__ ((format (printf, 3, 4)));
184extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
185 __attribute__ ((format (printf, 3, 0)));
186extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
187 __attribute__ ((format (printf, 3, 4)));
188extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
189 __attribute__ ((format (printf, 3, 0)));
e905914f
JF
190extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
191 __attribute__ ((format (printf, 2, 3)));
11443ec7 192extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4
LT
193
194extern int sscanf(const char *, const char *, ...)
195 __attribute__ ((format (scanf, 2, 3)));
196extern int vsscanf(const char *, const char *, va_list)
197 __attribute__ ((format (scanf, 2, 0)));
198
199extern int get_option(char **str, int *pint);
200extern char *get_options(const char *str, int nints, int *ints);
d974ae37 201extern unsigned long long memparse(const char *ptr, char **retptr);
1da177e4 202
5e376613 203extern int core_kernel_text(unsigned long addr);
1da177e4
LT
204extern int __kernel_text_address(unsigned long addr);
205extern int kernel_text_address(unsigned long addr);
ab7476cf 206extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 207
04a2e6a5
EB
208struct pid;
209extern struct pid *session_of_pgrp(struct pid *pgrp);
1da177e4 210
a0ad05c7
TR
211/*
212 * FW_BUG
213 * Add this to a message where you are sure the firmware is buggy or behaves
214 * really stupid or out of spec. Be aware that the responsible BIOS developer
215 * should be able to fix this issue or at least get a concrete idea of the
216 * problem by reading your message without the need of looking at the kernel
217 * code.
218 *
219 * Use it for definite and high priority BIOS bugs.
220 *
221 * FW_WARN
222 * Use it for not that clear (e.g. could the kernel messed up things already?)
223 * and medium priority BIOS bugs.
224 *
225 * FW_INFO
226 * Use this one if you want to tell the user or vendor about something
227 * suspicious, but generally harmless related to the firmware.
228 *
229 * Use it for information or very low priority BIOS bugs.
230 */
231#define FW_BUG "[Firmware Bug]: "
232#define FW_WARN "[Firmware Warn]: "
233#define FW_INFO "[Firmware Info]: "
234
d59745ce 235#ifdef CONFIG_PRINTK
1da177e4
LT
236asmlinkage int vprintk(const char *fmt, va_list args)
237 __attribute__ ((format (printf, 1, 0)));
238asmlinkage int printk(const char * fmt, ...)
a586df06 239 __attribute__ ((format (printf, 1, 2))) __cold;
7ef3d2fd 240
717115e1 241extern struct ratelimit_state printk_ratelimit_state;
7ef3d2fd 242extern int printk_ratelimit(void);
7ef3d2fd
JP
243extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
244 unsigned int interval_msec);
f036be96
IM
245
246/*
247 * Print a one-time message (analogous to WARN_ONCE() et al):
248 */
249#define printk_once(x...) ({ \
250 static int __print_once = 1; \
251 \
252 if (__print_once) { \
253 __print_once = 0; \
254 printk(x); \
255 } \
256})
257
04d491ab 258void log_buf_kexec_setup(void);
d59745ce
MM
259#else
260static inline int vprintk(const char *s, va_list args)
261 __attribute__ ((format (printf, 1, 0)));
262static inline int vprintk(const char *s, va_list args) { return 0; }
263static inline int printk(const char *s, ...)
264 __attribute__ ((format (printf, 1, 2)));
a586df06 265static inline int __cold printk(const char *s, ...) { return 0; }
7ef3d2fd 266static inline int printk_ratelimit(void) { return 0; }
7ef3d2fd
JP
267static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
268 unsigned int interval_msec) \
269 { return false; }
f036be96
IM
270
271/* No effect, but we still get type checking even in the !PRINTK case: */
272#define printk_once(x...) printk(x)
273
04d491ab
NH
274static inline void log_buf_kexec_setup(void)
275{
276}
d59745ce 277#endif
1da177e4 278
ced9cd40
IM
279extern int printk_needs_cpu(int cpu);
280extern void printk_tick(void);
281
e17ba73b 282extern void asmlinkage __attribute__((format(printf, 1, 2)))
076f9776
IM
283 early_printk(const char *fmt, ...);
284
1da177e4
LT
285unsigned long int_sqrt(unsigned long);
286
1da177e4
LT
287static inline void console_silent(void)
288{
289 console_loglevel = 0;
290}
291
292static inline void console_verbose(void)
293{
294 if (console_loglevel)
295 console_loglevel = 15;
296}
297
298extern void bust_spinlocks(int yes);
e3e8a75d 299extern void wake_up_klogd(void);
1da177e4 300extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 301extern int panic_timeout;
1da177e4 302extern int panic_on_oops;
8da5adda 303extern int panic_on_unrecovered_nmi;
1da177e4 304extern const char *print_tainted(void);
25ddbb18
AK
305extern void add_taint(unsigned flag);
306extern int test_taint(unsigned flag);
307extern unsigned long get_taint(void);
b920de1b 308extern int root_mountflags;
1da177e4
LT
309
310/* Values used for system_state */
311extern enum system_states {
312 SYSTEM_BOOTING,
313 SYSTEM_RUNNING,
314 SYSTEM_HALT,
315 SYSTEM_POWER_OFF,
316 SYSTEM_RESTART,
729b4d4c 317 SYSTEM_SUSPEND_DISK,
1da177e4
LT
318} system_state;
319
25ddbb18
AK
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
26e9a397 330#define TAINT_CRAP 10
1da177e4 331
a586df06 332extern void dump_stack(void) __cold;
1da177e4 333
99eaf3c4
RD
334enum {
335 DUMP_PREFIX_NONE,
336 DUMP_PREFIX_ADDRESS,
337 DUMP_PREFIX_OFFSET
338};
c7909234
RD
339extern void hex_dump_to_buffer(const void *buf, size_t len,
340 int rowsize, int groupsize,
341 char *linebuf, size_t linebuflen, bool ascii);
342extern void print_hex_dump(const char *level, const char *prefix_str,
343 int prefix_type, int rowsize, int groupsize,
6a0ed91e 344 const void *buf, size_t len, bool ascii);
c7909234 345extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
eb9a9a56 346 const void *buf, size_t len);
3fc95772
HH
347
348extern const char hex_asc[];
349#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
350#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
351
352static inline char *pack_hex_byte(char *buf, u8 byte)
353{
354 *buf++ = hex_asc_hi(byte);
355 *buf++ = hex_asc_lo(byte);
356 return buf;
357}
99eaf3c4 358
d091c2f5
MS
359#ifndef pr_fmt
360#define pr_fmt(fmt) fmt
361#endif
362
363#define pr_emerg(fmt, ...) \
364 printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
365#define pr_alert(fmt, ...) \
366 printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
367#define pr_crit(fmt, ...) \
368 printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
369#define pr_err(fmt, ...) \
370 printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
371#define pr_warning(fmt, ...) \
372 printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
373#define pr_notice(fmt, ...) \
374 printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
375#define pr_info(fmt, ...) \
376 printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
311d0761
CG
377#define pr_cont(fmt, ...) \
378 printk(KERN_CONT fmt, ##__VA_ARGS__)
1f7c8234 379
4ccb4579
ME
380/* pr_devel() should produce zero code unless DEBUG is defined */
381#ifdef DEBUG
382#define pr_devel(fmt, ...) \
383 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
384#else
385#define pr_devel(fmt, ...) \
386 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
387#endif
388
1cc6daf2 389/* If you are writing a driver, please use dev_dbg instead */
d0d85ff9
CH
390#if defined(DEBUG)
391#define pr_debug(fmt, ...) \
392 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
e9d376f0 393#elif defined(CONFIG_DYNAMIC_DEBUG)
e6e66b02 394/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
346e15be 395#define pr_debug(fmt, ...) do { \
e6e66b02 396 dynamic_pr_debug(fmt, ##__VA_ARGS__); \
346e15be 397 } while (0)
1da177e4 398#else
d091c2f5
MS
399#define pr_debug(fmt, ...) \
400 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
1da177e4
LT
401#endif
402
526211bc
IM
403/*
404 * General tracing related utility functions - trace_printk(),
2002c258
SR
405 * tracing_on/tracing_off and tracing_start()/tracing_stop
406 *
407 * Use tracing_on/tracing_off when you want to quickly turn on or off
408 * tracing. It simply enables or disables the recording of the trace events.
409 * This also corresponds to the user space debugfs/tracing/tracing_on
410 * file, which gives a means for the kernel and userspace to interact.
411 * Place a tracing_off() in the kernel where you want tracing to end.
412 * From user space, examine the trace, and then echo 1 > tracing_on
413 * to continue tracing.
414 *
415 * tracing_stop/tracing_start has slightly more overhead. It is used
416 * by things like suspend to ram where disabling the recording of the
417 * trace is not enough, but tracing must actually stop because things
418 * like calling smp_processor_id() may crash the system.
419 *
420 * Most likely, you want to use tracing_on/tracing_off.
526211bc 421 */
2002c258
SR
422#ifdef CONFIG_RING_BUFFER
423void tracing_on(void);
424void tracing_off(void);
425/* trace_off_permanent stops recording with no way to bring it back */
426void tracing_off_permanent(void);
427int tracing_is_on(void);
428#else
429static inline void tracing_on(void) { }
430static inline void tracing_off(void) { }
431static inline void tracing_off_permanent(void) { }
432static inline int tracing_is_on(void) { return 0; }
433#endif
526211bc
IM
434#ifdef CONFIG_TRACING
435extern void tracing_start(void);
436extern void tracing_stop(void);
437extern void ftrace_off_permanent(void);
438
439extern void
440ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
441
769b0441
FW
442static inline void __attribute__ ((format (printf, 1, 2)))
443____trace_printk_check_format(const char *fmt, ...)
444{
445}
446#define __trace_printk_check_format(fmt, args...) \
447do { \
448 if (0) \
449 ____trace_printk_check_format(fmt, ##args); \
450} while (0)
451
526211bc
IM
452/**
453 * trace_printk - printf formatting in the ftrace buffer
454 * @fmt: the printf format for printing
455 *
456 * Note: __trace_printk is an internal function for trace_printk and
457 * the @ip is passed in via the trace_printk macro.
458 *
459 * This function allows a kernel developer to debug fast path sections
460 * that printk is not appropriate for. By scattering in various
461 * printk like tracing in the code, a developer can quickly see
462 * where problems are occurring.
463 *
464 * This is intended as a debugging tool for the developer only.
465 * Please refrain from leaving trace_printks scattered around in
466 * your code.
467 */
769b0441
FW
468
469#define trace_printk(fmt, args...) \
470do { \
769b0441 471 __trace_printk_check_format(fmt, ##args); \
48ead020
FW
472 if (__builtin_constant_p(fmt)) { \
473 static const char *trace_printk_fmt \
474 __attribute__((section("__trace_printk_fmt"))) = \
475 __builtin_constant_p(fmt) ? fmt : NULL; \
476 \
477 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
478 } else \
479 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
480} while (0)
481
48ead020
FW
482extern int
483__trace_bprintk(unsigned long ip, const char *fmt, ...)
484 __attribute__ ((format (printf, 2, 3)));
485
526211bc
IM
486extern int
487__trace_printk(unsigned long ip, const char *fmt, ...)
488 __attribute__ ((format (printf, 2, 3)));
769b0441 489
48ead020
FW
490/*
491 * The double __builtin_constant_p is because gcc will give us an error
492 * if we try to allocate the static variable to fmt if it is not a
493 * constant. Even with the outer if statement.
494 */
769b0441
FW
495#define ftrace_vprintk(fmt, vargs) \
496do { \
48ead020
FW
497 if (__builtin_constant_p(fmt)) { \
498 static const char *trace_printk_fmt \
499 __attribute__((section("__trace_printk_fmt"))) = \
500 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 501 \
48ead020
FW
502 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
503 } else \
504 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
505} while (0)
506
48ead020
FW
507extern int
508__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
509
526211bc
IM
510extern int
511__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 512
526211bc
IM
513extern void ftrace_dump(void);
514#else
515static inline void
516ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
517static inline int
518trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
519
520static inline void tracing_start(void) { }
521static inline void tracing_stop(void) { }
522static inline void ftrace_off_permanent(void) { }
523static inline int
524trace_printk(const char *fmt, ...)
525{
526 return 0;
527}
528static inline int
529ftrace_vprintk(const char *fmt, va_list ap)
530{
531 return 0;
532}
533static inline void ftrace_dump(void) { }
769b0441 534#endif /* CONFIG_TRACING */
526211bc 535
1da177e4
LT
536/*
537 * Display an IP address in readable format.
538 */
539
540#define NIPQUAD(addr) \
541 ((unsigned char *)&addr)[0], \
542 ((unsigned char *)&addr)[1], \
543 ((unsigned char *)&addr)[2], \
544 ((unsigned char *)&addr)[3]
46b86a2d 545#define NIPQUAD_FMT "%u.%u.%u.%u"
1da177e4 546
1da177e4 547/*
bdf4bbaa 548 * min()/max()/clamp() macros that also do
1da177e4
LT
549 * strict type-checking.. See the
550 * "unnecessary" pointer comparison.
551 */
bdf4bbaa
HH
552#define min(x, y) ({ \
553 typeof(x) _min1 = (x); \
554 typeof(y) _min2 = (y); \
555 (void) (&_min1 == &_min2); \
556 _min1 < _min2 ? _min1 : _min2; })
557
558#define max(x, y) ({ \
559 typeof(x) _max1 = (x); \
560 typeof(y) _max2 = (y); \
561 (void) (&_max1 == &_max2); \
562 _max1 > _max2 ? _max1 : _max2; })
563
564/**
565 * clamp - return a value clamped to a given range with strict typechecking
566 * @val: current value
567 * @min: minimum allowable value
568 * @max: maximum allowable value
569 *
570 * This macro does strict typechecking of min/max to make sure they are of the
571 * same type as val. See the unnecessary pointer comparisons.
572 */
573#define clamp(val, min, max) ({ \
574 typeof(val) __val = (val); \
575 typeof(min) __min = (min); \
576 typeof(max) __max = (max); \
577 (void) (&__val == &__min); \
578 (void) (&__val == &__max); \
579 __val = __val < __min ? __min: __val; \
580 __val > __max ? __max: __val; })
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LT
581
582/*
583 * ..and if you can't take the strict
584 * types, you can specify one yourself.
585 *
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HH
586 * Or not use min/max/clamp at all, of course.
587 */
588#define min_t(type, x, y) ({ \
589 type __min1 = (x); \
590 type __min2 = (y); \
591 __min1 < __min2 ? __min1: __min2; })
592
593#define max_t(type, x, y) ({ \
594 type __max1 = (x); \
595 type __max2 = (y); \
596 __max1 > __max2 ? __max1: __max2; })
597
598/**
599 * clamp_t - return a value clamped to a given range using a given type
600 * @type: the type of variable to use
601 * @val: current value
602 * @min: minimum allowable value
603 * @max: maximum allowable value
604 *
605 * This macro does no typechecking and uses temporary variables of type
606 * 'type' to make all the comparisons.
1da177e4 607 */
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HH
608#define clamp_t(type, val, min, max) ({ \
609 type __val = (val); \
610 type __min = (min); \
611 type __max = (max); \
612 __val = __val < __min ? __min: __val; \
613 __val > __max ? __max: __val; })
1da177e4 614
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HH
615/**
616 * clamp_val - return a value clamped to a given range using val's type
617 * @val: current value
618 * @min: minimum allowable value
619 * @max: maximum allowable value
620 *
621 * This macro does no typechecking and uses temporary variables of whatever
622 * type the input argument 'val' is. This is useful when val is an unsigned
623 * type and min and max are literals that will otherwise be assigned a signed
624 * integer type.
625 */
626#define clamp_val(val, min, max) ({ \
627 typeof(val) __val = (val); \
628 typeof(val) __min = (min); \
629 typeof(val) __max = (max); \
630 __val = __val < __min ? __min: __val; \
631 __val > __max ? __max: __val; })
1da177e4 632
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WF
633
634/*
635 * swap - swap value of @a and @b
636 */
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PZ
637#define swap(a, b) \
638 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 639
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LT
640/**
641 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
642 * @ptr: the pointer to the member.
643 * @type: the type of the container struct this is embedded in.
644 * @member: the name of the member within the struct.
645 *
646 */
647#define container_of(ptr, type, member) ({ \
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DW
648 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
649 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 650
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KM
651struct sysinfo;
652extern int do_sysinfo(struct sysinfo *info);
653
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LT
654#endif /* __KERNEL__ */
655
656#define SI_LOAD_SHIFT 16
657struct sysinfo {
658 long uptime; /* Seconds since boot */
659 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
660 unsigned long totalram; /* Total usable main memory size */
661 unsigned long freeram; /* Available memory size */
662 unsigned long sharedram; /* Amount of shared memory */
663 unsigned long bufferram; /* Memory used by buffers */
664 unsigned long totalswap; /* Total swap space size */
665 unsigned long freeswap; /* swap space still available */
666 unsigned short procs; /* Number of current processes */
667 unsigned short pad; /* explicit padding for m68k */
668 unsigned long totalhigh; /* Total high memory size */
669 unsigned long freehigh; /* Available high memory size */
670 unsigned int mem_unit; /* Memory unit size in bytes */
671 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
672};
673
c0398ee6 674/* Force a compilation error if condition is true */
921717a2 675#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
1da177e4 676
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JB
677/* Force a compilation error if condition is true, but also produce a
678 result (of value 0 and type size_t), so the expression can be used
679 e.g. in a structure initializer (or where-ever else comma expressions
680 aren't permitted). */
681#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
682
1da177e4 683/* Trap pasters of __FUNCTION__ at compile-time */
1da177e4 684#define __FUNCTION__ (__func__)
1da177e4 685
08e0f6a9
CL
686/* This helps us to avoid #ifdef CONFIG_NUMA */
687#ifdef CONFIG_NUMA
688#define NUMA_BUILD 1
689#else
690#define NUMA_BUILD 0
691#endif
692
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SR
693/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
694#ifdef CONFIG_FTRACE_MCOUNT_RECORD
695# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
696#endif
697
1da177e4 698#endif