1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
5 * 'kernel.h' contains some often-used function prototypes etc
7 #define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
8 #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
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/dynamic_debug.h>
21 #include <asm/byteorder.h>
24 extern const char linux_banner[];
25 extern const char linux_proc_banner[];
27 #define USHRT_MAX ((u16)(~0U))
28 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
29 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
30 #define INT_MAX ((int)(~0U>>1))
31 #define INT_MIN (-INT_MAX - 1)
32 #define UINT_MAX (~0U)
33 #define LONG_MAX ((long)(~0UL>>1))
34 #define LONG_MIN (-LONG_MAX - 1)
35 #define ULONG_MAX (~0UL)
36 #define LLONG_MAX ((long long)(~0ULL>>1))
37 #define LLONG_MIN (-LLONG_MAX - 1)
38 #define ULLONG_MAX (~0ULL)
40 #define STACK_MAGIC 0xdeadbeef
42 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
43 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
44 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
45 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
47 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
50 * This looks more complex than it should be. But we need to
51 * get the type for the ~ right in round_down (it needs to be
52 * as wide as the result!), and we want to evaluate the macro
53 * arguments just once each.
55 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
56 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
57 #define round_down(x, y) ((x) & ~__round_mask(x, y))
59 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
60 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
61 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
62 #define DIV_ROUND_CLOSEST(x, divisor)( \
64 typeof(divisor) __divisor = divisor; \
65 (((x) + ((__divisor) / 2)) / (__divisor)); \
69 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
70 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
73 # include <asm/div64.h>
74 # define sector_div(a, b) do_div(a, b)
76 # define sector_div(n, b)( \
87 * upper_32_bits - return bits 32-63 of a number
88 * @n: the number we're accessing
90 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
91 * the "right shift count >= width of type" warning when that quantity is
94 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
97 * lower_32_bits - return bits 0-31 of a number
98 * @n: the number we're accessing
100 #define lower_32_bits(n) ((u32)(n))
102 #define KERN_EMERG "<0>" /* system is unusable */
103 #define KERN_ALERT "<1>" /* action must be taken immediately */
104 #define KERN_CRIT "<2>" /* critical conditions */
105 #define KERN_ERR "<3>" /* error conditions */
106 #define KERN_WARNING "<4>" /* warning conditions */
107 #define KERN_NOTICE "<5>" /* normal but significant condition */
108 #define KERN_INFO "<6>" /* informational */
109 #define KERN_DEBUG "<7>" /* debug-level messages */
111 /* Use the default kernel loglevel */
112 #define KERN_DEFAULT "<d>"
114 * Annotation for a "continued" line of log printout (only done after a
115 * line that had no enclosing \n). Only to be used by core/arch code
116 * during early bootup (a continued line is not SMP-safe otherwise).
118 #define KERN_CONT "<c>"
120 extern int console_printk[];
122 #define console_loglevel (console_printk[0])
123 #define default_message_loglevel (console_printk[1])
124 #define minimum_console_loglevel (console_printk[2])
125 #define default_console_loglevel (console_printk[3])
131 #ifdef CONFIG_PREEMPT_VOLUNTARY
132 extern int _cond_resched(void);
133 # define might_resched() _cond_resched()
135 # define might_resched() do { } while (0)
138 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
139 void __might_sleep(const char *file, int line, int preempt_offset);
141 * might_sleep - annotation for functions that can sleep
143 * this macro will print a stack trace if it is executed in an atomic
144 * context (spinlock, irq-handler, ...).
146 * This is a useful debugging help to be able to catch problems early and not
147 * be bitten later when the calling function happens to sleep when it is not
150 # define might_sleep() \
151 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
153 static inline void __might_sleep(const char *file, int line,
154 int preempt_offset) { }
155 # define might_sleep() do { might_resched(); } while (0)
158 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
162 (__x < 0) ? -__x : __x; \
165 #ifdef CONFIG_PROVE_LOCKING
166 void might_fault(void);
168 static inline void might_fault(void)
179 extern struct atomic_notifier_head panic_notifier_list;
180 extern long (*panic_blink)(long time);
181 NORET_TYPE void panic(const char * fmt, ...)
182 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
183 extern void oops_enter(void);
184 extern void oops_exit(void);
185 extern int oops_may_print(void);
186 NORET_TYPE void do_exit(long error_code)
188 NORET_TYPE void complete_and_exit(struct completion *, long)
190 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
191 extern long simple_strtol(const char *,char **,unsigned int);
192 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
193 extern long long simple_strtoll(const char *,char **,unsigned int);
194 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
195 extern int strict_strtol(const char *, unsigned int, long *);
196 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
197 extern int strict_strtoll(const char *, unsigned int, long long *);
198 extern int sprintf(char * buf, const char * fmt, ...)
199 __attribute__ ((format (printf, 2, 3)));
200 extern int vsprintf(char *buf, const char *, va_list)
201 __attribute__ ((format (printf, 2, 0)));
202 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
203 __attribute__ ((format (printf, 3, 4)));
204 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
205 __attribute__ ((format (printf, 3, 0)));
206 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
207 __attribute__ ((format (printf, 3, 4)));
208 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
209 __attribute__ ((format (printf, 3, 0)));
210 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
211 __attribute__ ((format (printf, 2, 3)));
212 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
214 extern int sscanf(const char *, const char *, ...)
215 __attribute__ ((format (scanf, 2, 3)));
216 extern int vsscanf(const char *, const char *, va_list)
217 __attribute__ ((format (scanf, 2, 0)));
219 extern int get_option(char **str, int *pint);
220 extern char *get_options(const char *str, int nints, int *ints);
221 extern unsigned long long memparse(const char *ptr, char **retptr);
223 extern int core_kernel_text(unsigned long addr);
224 extern int __kernel_text_address(unsigned long addr);
225 extern int kernel_text_address(unsigned long addr);
226 extern int func_ptr_is_kernel_text(void *ptr);
229 extern struct pid *session_of_pgrp(struct pid *pgrp);
233 * Add this to a message where you are sure the firmware is buggy or behaves
234 * really stupid or out of spec. Be aware that the responsible BIOS developer
235 * should be able to fix this issue or at least get a concrete idea of the
236 * problem by reading your message without the need of looking at the kernel
239 * Use it for definite and high priority BIOS bugs.
242 * Use it for not that clear (e.g. could the kernel messed up things already?)
243 * and medium priority BIOS bugs.
246 * Use this one if you want to tell the user or vendor about something
247 * suspicious, but generally harmless related to the firmware.
249 * Use it for information or very low priority BIOS bugs.
251 #define FW_BUG "[Firmware Bug]: "
252 #define FW_WARN "[Firmware Warn]: "
253 #define FW_INFO "[Firmware Info]: "
257 * Add this to a message for hardware errors, so that user can report
258 * it to hardware vendor instead of LKML or software vendor.
260 #define HW_ERR "[Hardware Error]: "
263 asmlinkage int vprintk(const char *fmt, va_list args)
264 __attribute__ ((format (printf, 1, 0)));
265 asmlinkage int printk(const char * fmt, ...)
266 __attribute__ ((format (printf, 1, 2))) __cold;
268 extern int __printk_ratelimit(const char *func);
269 #define printk_ratelimit() __printk_ratelimit(__func__)
270 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
271 unsigned int interval_msec);
273 extern int printk_delay_msec;
276 * Print a one-time message (analogous to WARN_ONCE() et al):
278 #define printk_once(x...) ({ \
279 static bool __print_once; \
281 if (!__print_once) { \
282 __print_once = true; \
287 void log_buf_kexec_setup(void);
289 static inline int vprintk(const char *s, va_list args)
290 __attribute__ ((format (printf, 1, 0)));
291 static inline int vprintk(const char *s, va_list args) { return 0; }
292 static inline int printk(const char *s, ...)
293 __attribute__ ((format (printf, 1, 2)));
294 static inline int __cold printk(const char *s, ...) { return 0; }
295 static inline int printk_ratelimit(void) { return 0; }
296 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
297 unsigned int interval_msec) \
300 /* No effect, but we still get type checking even in the !PRINTK case: */
301 #define printk_once(x...) printk(x)
303 static inline void log_buf_kexec_setup(void)
308 extern int printk_needs_cpu(int cpu);
309 extern void printk_tick(void);
311 extern void asmlinkage __attribute__((format(printf, 1, 2)))
312 early_printk(const char *fmt, ...);
314 unsigned long int_sqrt(unsigned long);
316 static inline void console_silent(void)
318 console_loglevel = 0;
321 static inline void console_verbose(void)
323 if (console_loglevel)
324 console_loglevel = 15;
327 extern void bust_spinlocks(int yes);
328 extern void wake_up_klogd(void);
329 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
330 extern int panic_timeout;
331 extern int panic_on_oops;
332 extern int panic_on_unrecovered_nmi;
333 extern int panic_on_io_nmi;
334 extern const char *print_tainted(void);
335 extern void add_taint(unsigned flag);
336 extern int test_taint(unsigned flag);
337 extern unsigned long get_taint(void);
338 extern int root_mountflags;
340 /* Values used for system_state */
341 extern enum system_states {
350 #define TAINT_PROPRIETARY_MODULE 0
351 #define TAINT_FORCED_MODULE 1
352 #define TAINT_UNSAFE_SMP 2
353 #define TAINT_FORCED_RMMOD 3
354 #define TAINT_MACHINE_CHECK 4
355 #define TAINT_BAD_PAGE 5
358 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
360 #define TAINT_CRAP 10
361 #define TAINT_FIRMWARE_WORKAROUND 11
363 extern void dump_stack(void) __cold;
370 extern void hex_dump_to_buffer(const void *buf, size_t len,
371 int rowsize, int groupsize,
372 char *linebuf, size_t linebuflen, bool ascii);
373 extern void print_hex_dump(const char *level, const char *prefix_str,
374 int prefix_type, int rowsize, int groupsize,
375 const void *buf, size_t len, bool ascii);
376 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
377 const void *buf, size_t len);
379 extern const char hex_asc[];
380 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
381 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
383 static inline char *pack_hex_byte(char *buf, u8 byte)
385 *buf++ = hex_asc_hi(byte);
386 *buf++ = hex_asc_lo(byte);
390 extern int hex_to_bin(char ch);
393 #define pr_fmt(fmt) fmt
396 #define pr_emerg(fmt, ...) \
397 printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
398 #define pr_alert(fmt, ...) \
399 printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
400 #define pr_crit(fmt, ...) \
401 printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
402 #define pr_err(fmt, ...) \
403 printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
404 #define pr_warning(fmt, ...) \
405 printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
406 #define pr_warn pr_warning
407 #define pr_notice(fmt, ...) \
408 printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
409 #define pr_info(fmt, ...) \
410 printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
411 #define pr_cont(fmt, ...) \
412 printk(KERN_CONT fmt, ##__VA_ARGS__)
414 /* pr_devel() should produce zero code unless DEBUG is defined */
416 #define pr_devel(fmt, ...) \
417 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
419 #define pr_devel(fmt, ...) \
420 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
423 /* If you are writing a driver, please use dev_dbg instead */
425 #define pr_debug(fmt, ...) \
426 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
427 #elif defined(CONFIG_DYNAMIC_DEBUG)
428 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
429 #define pr_debug(fmt, ...) \
430 dynamic_pr_debug(fmt, ##__VA_ARGS__)
432 #define pr_debug(fmt, ...) \
433 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
437 * ratelimited messages with local ratelimit_state,
438 * no local ratelimit_state used in the !PRINTK case
441 #define printk_ratelimited(fmt, ...) ({ \
442 static DEFINE_RATELIMIT_STATE(_rs, \
443 DEFAULT_RATELIMIT_INTERVAL, \
444 DEFAULT_RATELIMIT_BURST); \
446 if (__ratelimit(&_rs)) \
447 printk(fmt, ##__VA_ARGS__); \
450 /* No effect, but we still get type checking even in the !PRINTK case: */
451 #define printk_ratelimited printk
454 #define pr_emerg_ratelimited(fmt, ...) \
455 printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
456 #define pr_alert_ratelimited(fmt, ...) \
457 printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
458 #define pr_crit_ratelimited(fmt, ...) \
459 printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
460 #define pr_err_ratelimited(fmt, ...) \
461 printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
462 #define pr_warning_ratelimited(fmt, ...) \
463 printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
464 #define pr_warn_ratelimited pr_warning_ratelimited
465 #define pr_notice_ratelimited(fmt, ...) \
466 printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
467 #define pr_info_ratelimited(fmt, ...) \
468 printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
469 /* no pr_cont_ratelimited, don't do that... */
470 /* If you are writing a driver, please use dev_dbg instead */
472 #define pr_debug_ratelimited(fmt, ...) \
473 printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
475 #define pr_debug_ratelimited(fmt, ...) \
476 ({ if (0) printk_ratelimited(KERN_DEBUG pr_fmt(fmt), \
477 ##__VA_ARGS__); 0; })
481 * General tracing related utility functions - trace_printk(),
482 * tracing_on/tracing_off and tracing_start()/tracing_stop
484 * Use tracing_on/tracing_off when you want to quickly turn on or off
485 * tracing. It simply enables or disables the recording of the trace events.
486 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
487 * file, which gives a means for the kernel and userspace to interact.
488 * Place a tracing_off() in the kernel where you want tracing to end.
489 * From user space, examine the trace, and then echo 1 > tracing_on
490 * to continue tracing.
492 * tracing_stop/tracing_start has slightly more overhead. It is used
493 * by things like suspend to ram where disabling the recording of the
494 * trace is not enough, but tracing must actually stop because things
495 * like calling smp_processor_id() may crash the system.
497 * Most likely, you want to use tracing_on/tracing_off.
499 #ifdef CONFIG_RING_BUFFER
500 void tracing_on(void);
501 void tracing_off(void);
502 /* trace_off_permanent stops recording with no way to bring it back */
503 void tracing_off_permanent(void);
504 int tracing_is_on(void);
506 static inline void tracing_on(void) { }
507 static inline void tracing_off(void) { }
508 static inline void tracing_off_permanent(void) { }
509 static inline int tracing_is_on(void) { return 0; }
512 enum ftrace_dump_mode {
518 #ifdef CONFIG_TRACING
519 extern void tracing_start(void);
520 extern void tracing_stop(void);
521 extern void ftrace_off_permanent(void);
523 static inline void __attribute__ ((format (printf, 1, 2)))
524 ____trace_printk_check_format(const char *fmt, ...)
527 #define __trace_printk_check_format(fmt, args...) \
530 ____trace_printk_check_format(fmt, ##args); \
534 * trace_printk - printf formatting in the ftrace buffer
535 * @fmt: the printf format for printing
537 * Note: __trace_printk is an internal function for trace_printk and
538 * the @ip is passed in via the trace_printk macro.
540 * This function allows a kernel developer to debug fast path sections
541 * that printk is not appropriate for. By scattering in various
542 * printk like tracing in the code, a developer can quickly see
543 * where problems are occurring.
545 * This is intended as a debugging tool for the developer only.
546 * Please refrain from leaving trace_printks scattered around in
550 #define trace_printk(fmt, args...) \
552 __trace_printk_check_format(fmt, ##args); \
553 if (__builtin_constant_p(fmt)) { \
554 static const char *trace_printk_fmt \
555 __attribute__((section("__trace_printk_fmt"))) = \
556 __builtin_constant_p(fmt) ? fmt : NULL; \
558 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
560 __trace_printk(_THIS_IP_, fmt, ##args); \
564 __trace_bprintk(unsigned long ip, const char *fmt, ...)
565 __attribute__ ((format (printf, 2, 3)));
568 __trace_printk(unsigned long ip, const char *fmt, ...)
569 __attribute__ ((format (printf, 2, 3)));
571 extern void trace_dump_stack(void);
574 * The double __builtin_constant_p is because gcc will give us an error
575 * if we try to allocate the static variable to fmt if it is not a
576 * constant. Even with the outer if statement.
578 #define ftrace_vprintk(fmt, vargs) \
580 if (__builtin_constant_p(fmt)) { \
581 static const char *trace_printk_fmt \
582 __attribute__((section("__trace_printk_fmt"))) = \
583 __builtin_constant_p(fmt) ? fmt : NULL; \
585 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
587 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
591 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
594 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
596 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
599 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
601 static inline void tracing_start(void) { }
602 static inline void tracing_stop(void) { }
603 static inline void ftrace_off_permanent(void) { }
604 static inline void trace_dump_stack(void) { }
606 trace_printk(const char *fmt, ...)
611 ftrace_vprintk(const char *fmt, va_list ap)
615 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
616 #endif /* CONFIG_TRACING */
619 * Display an IP address in readable format.
622 #define NIPQUAD(addr) \
623 ((unsigned char *)&addr)[0], \
624 ((unsigned char *)&addr)[1], \
625 ((unsigned char *)&addr)[2], \
626 ((unsigned char *)&addr)[3]
627 #define NIPQUAD_FMT "%u.%u.%u.%u"
630 * min()/max()/clamp() macros that also do
631 * strict type-checking.. See the
632 * "unnecessary" pointer comparison.
634 #define min(x, y) ({ \
635 typeof(x) _min1 = (x); \
636 typeof(y) _min2 = (y); \
637 (void) (&_min1 == &_min2); \
638 _min1 < _min2 ? _min1 : _min2; })
640 #define max(x, y) ({ \
641 typeof(x) _max1 = (x); \
642 typeof(y) _max2 = (y); \
643 (void) (&_max1 == &_max2); \
644 _max1 > _max2 ? _max1 : _max2; })
647 * clamp - return a value clamped to a given range with strict typechecking
648 * @val: current value
649 * @min: minimum allowable value
650 * @max: maximum allowable value
652 * This macro does strict typechecking of min/max to make sure they are of the
653 * same type as val. See the unnecessary pointer comparisons.
655 #define clamp(val, min, max) ({ \
656 typeof(val) __val = (val); \
657 typeof(min) __min = (min); \
658 typeof(max) __max = (max); \
659 (void) (&__val == &__min); \
660 (void) (&__val == &__max); \
661 __val = __val < __min ? __min: __val; \
662 __val > __max ? __max: __val; })
665 * ..and if you can't take the strict
666 * types, you can specify one yourself.
668 * Or not use min/max/clamp at all, of course.
670 #define min_t(type, x, y) ({ \
673 __min1 < __min2 ? __min1: __min2; })
675 #define max_t(type, x, y) ({ \
678 __max1 > __max2 ? __max1: __max2; })
681 * clamp_t - return a value clamped to a given range using a given type
682 * @type: the type of variable to use
683 * @val: current value
684 * @min: minimum allowable value
685 * @max: maximum allowable value
687 * This macro does no typechecking and uses temporary variables of type
688 * 'type' to make all the comparisons.
690 #define clamp_t(type, val, min, max) ({ \
691 type __val = (val); \
692 type __min = (min); \
693 type __max = (max); \
694 __val = __val < __min ? __min: __val; \
695 __val > __max ? __max: __val; })
698 * clamp_val - return a value clamped to a given range using val's type
699 * @val: current value
700 * @min: minimum allowable value
701 * @max: maximum allowable value
703 * This macro does no typechecking and uses temporary variables of whatever
704 * type the input argument 'val' is. This is useful when val is an unsigned
705 * type and min and max are literals that will otherwise be assigned a signed
708 #define clamp_val(val, min, max) ({ \
709 typeof(val) __val = (val); \
710 typeof(val) __min = (min); \
711 typeof(val) __max = (max); \
712 __val = __val < __min ? __min: __val; \
713 __val > __max ? __max: __val; })
717 * swap - swap value of @a and @b
720 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
723 * container_of - cast a member of a structure out to the containing structure
724 * @ptr: the pointer to the member.
725 * @type: the type of the container struct this is embedded in.
726 * @member: the name of the member within the struct.
729 #define container_of(ptr, type, member) ({ \
730 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
731 (type *)( (char *)__mptr - offsetof(type,member) );})
734 extern int do_sysinfo(struct sysinfo *info);
736 #endif /* __KERNEL__ */
738 #define SI_LOAD_SHIFT 16
740 long uptime; /* Seconds since boot */
741 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
742 unsigned long totalram; /* Total usable main memory size */
743 unsigned long freeram; /* Available memory size */
744 unsigned long sharedram; /* Amount of shared memory */
745 unsigned long bufferram; /* Memory used by buffers */
746 unsigned long totalswap; /* Total swap space size */
747 unsigned long freeswap; /* swap space still available */
748 unsigned short procs; /* Number of current processes */
749 unsigned short pad; /* explicit padding for m68k */
750 unsigned long totalhigh; /* Total high memory size */
751 unsigned long freehigh; /* Available high memory size */
752 unsigned int mem_unit; /* Memory unit size in bytes */
753 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
756 /* Force a compilation error if condition is true */
757 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
759 /* Force a compilation error if condition is constant and true */
760 #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
762 /* Force a compilation error if a constant expression is not a power of 2 */
763 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
764 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
766 /* Force a compilation error if condition is true, but also produce a
767 result (of value 0 and type size_t), so the expression can be used
768 e.g. in a structure initializer (or where-ever else comma expressions
769 aren't permitted). */
770 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
771 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
773 /* Trap pasters of __FUNCTION__ at compile-time */
774 #define __FUNCTION__ (__func__)
776 /* This helps us to avoid #ifdef CONFIG_NUMA */
783 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
784 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
785 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD