xref: /linux-6.15/include/linux/kernel.h (revision 4fafd5b0)
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>
16 #include <linux/log2.h>
17 #include <linux/typecheck.h>
18 #include <linux/ratelimit.h>
19 #include <linux/dynamic_printk.h>
20 #include <asm/byteorder.h>
21 #include <asm/bug.h>
22 
23 extern const char linux_banner[];
24 extern const char linux_proc_banner[];
25 
26 #define USHORT_MAX	((u16)(~0U))
27 #define SHORT_MAX	((s16)(USHORT_MAX>>1))
28 #define SHORT_MIN	(-SHORT_MAX - 1)
29 #define INT_MAX		((int)(~0U>>1))
30 #define INT_MIN		(-INT_MAX - 1)
31 #define UINT_MAX	(~0U)
32 #define LONG_MAX	((long)(~0UL>>1))
33 #define LONG_MIN	(-LONG_MAX - 1)
34 #define ULONG_MAX	(~0UL)
35 #define LLONG_MAX	((long long)(~0ULL>>1))
36 #define LLONG_MIN	(-LLONG_MAX - 1)
37 #define ULLONG_MAX	(~0ULL)
38 
39 #define STACK_MAGIC	0xdeadbeef
40 
41 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
42 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
43 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
44 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
45 
46 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
47 
48 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
49 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
50 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
51 #define DIV_ROUND_CLOSEST(x, divisor)(			\
52 {							\
53 	typeof(divisor) __divisor = divisor;		\
54 	(((x) + ((__divisor) / 2)) / (__divisor));	\
55 }							\
56 )
57 
58 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
59 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
60 
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 
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 
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 
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 
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 
107 extern 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 
114 struct completion;
115 struct pt_regs;
116 struct user;
117 
118 #ifdef CONFIG_PREEMPT_VOLUNTARY
119 extern int _cond_resched(void);
120 # define might_resched() _cond_resched()
121 #else
122 # define might_resched() do { } while (0)
123 #endif
124 
125 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
126   void __might_sleep(char *file, int line);
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
134  * be bitten later when the calling function happens to sleep when it is not
135  * supposed to.
136  */
137 # define might_sleep() \
138 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
139 #else
140 # define might_sleep() do { might_resched(); } while (0)
141 #endif
142 
143 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
144 
145 #define abs(x) ({				\
146 		int __x = (x);			\
147 		(__x < 0) ? -__x : __x;		\
148 	})
149 
150 #ifdef CONFIG_PROVE_LOCKING
151 void might_fault(void);
152 #else
153 static inline void might_fault(void)
154 {
155 	might_sleep();
156 }
157 #endif
158 
159 extern struct atomic_notifier_head panic_notifier_list;
160 extern long (*panic_blink)(long time);
161 NORET_TYPE void panic(const char * fmt, ...)
162 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
163 extern void oops_enter(void);
164 extern void oops_exit(void);
165 extern int oops_may_print(void);
166 NORET_TYPE void do_exit(long error_code)
167 	ATTRIB_NORET;
168 NORET_TYPE void complete_and_exit(struct completion *, long)
169 	ATTRIB_NORET;
170 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
171 extern long simple_strtol(const char *,char **,unsigned int);
172 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
173 extern long long simple_strtoll(const char *,char **,unsigned int);
174 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
175 extern int strict_strtol(const char *, unsigned int, long *);
176 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
177 extern int strict_strtoll(const char *, unsigned int, long long *);
178 extern int sprintf(char * buf, const char * fmt, ...)
179 	__attribute__ ((format (printf, 2, 3)));
180 extern int vsprintf(char *buf, const char *, va_list)
181 	__attribute__ ((format (printf, 2, 0)));
182 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
183 	__attribute__ ((format (printf, 3, 4)));
184 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
185 	__attribute__ ((format (printf, 3, 0)));
186 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
187 	__attribute__ ((format (printf, 3, 4)));
188 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
189 	__attribute__ ((format (printf, 3, 0)));
190 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
191 	__attribute__ ((format (printf, 2, 3)));
192 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
193 
194 extern int sscanf(const char *, const char *, ...)
195 	__attribute__ ((format (scanf, 2, 3)));
196 extern int vsscanf(const char *, const char *, va_list)
197 	__attribute__ ((format (scanf, 2, 0)));
198 
199 extern int get_option(char **str, int *pint);
200 extern char *get_options(const char *str, int nints, int *ints);
201 extern unsigned long long memparse(const char *ptr, char **retptr);
202 
203 extern int core_kernel_text(unsigned long addr);
204 extern int __kernel_text_address(unsigned long addr);
205 extern int kernel_text_address(unsigned long addr);
206 extern int func_ptr_is_kernel_text(void *ptr);
207 
208 struct pid;
209 extern struct pid *session_of_pgrp(struct pid *pgrp);
210 
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 
235 #ifdef CONFIG_PRINTK
236 asmlinkage int vprintk(const char *fmt, va_list args)
237 	__attribute__ ((format (printf, 1, 0)));
238 asmlinkage int printk(const char * fmt, ...)
239 	__attribute__ ((format (printf, 1, 2))) __cold;
240 
241 extern struct ratelimit_state printk_ratelimit_state;
242 extern int printk_ratelimit(void);
243 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
244 				   unsigned int interval_msec);
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 
258 #else
259 static inline int vprintk(const char *s, va_list args)
260 	__attribute__ ((format (printf, 1, 0)));
261 static inline int vprintk(const char *s, va_list args) { return 0; }
262 static inline int printk(const char *s, ...)
263 	__attribute__ ((format (printf, 1, 2)));
264 static inline int __cold printk(const char *s, ...) { return 0; }
265 static inline int printk_ratelimit(void) { return 0; }
266 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
267 					  unsigned int interval_msec)	\
268 		{ return false; }
269 
270 /* No effect, but we still get type checking even in the !PRINTK case: */
271 #define printk_once(x...) printk(x)
272 
273 #endif
274 
275 extern int printk_needs_cpu(int cpu);
276 extern void printk_tick(void);
277 
278 extern void asmlinkage __attribute__((format(printf, 1, 2)))
279 	early_printk(const char *fmt, ...);
280 
281 unsigned long int_sqrt(unsigned long);
282 
283 static inline void console_silent(void)
284 {
285 	console_loglevel = 0;
286 }
287 
288 static inline void console_verbose(void)
289 {
290 	if (console_loglevel)
291 		console_loglevel = 15;
292 }
293 
294 extern void bust_spinlocks(int yes);
295 extern void wake_up_klogd(void);
296 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
297 extern int panic_timeout;
298 extern int panic_on_oops;
299 extern int panic_on_unrecovered_nmi;
300 extern const char *print_tainted(void);
301 extern void add_taint(unsigned flag);
302 extern int test_taint(unsigned flag);
303 extern unsigned long get_taint(void);
304 extern int root_mountflags;
305 
306 /* Values used for system_state */
307 extern enum system_states {
308 	SYSTEM_BOOTING,
309 	SYSTEM_RUNNING,
310 	SYSTEM_HALT,
311 	SYSTEM_POWER_OFF,
312 	SYSTEM_RESTART,
313 	SYSTEM_SUSPEND_DISK,
314 } system_state;
315 
316 #define TAINT_PROPRIETARY_MODULE	0
317 #define TAINT_FORCED_MODULE		1
318 #define TAINT_UNSAFE_SMP		2
319 #define TAINT_FORCED_RMMOD		3
320 #define TAINT_MACHINE_CHECK		4
321 #define TAINT_BAD_PAGE			5
322 #define TAINT_USER			6
323 #define TAINT_DIE			7
324 #define TAINT_OVERRIDDEN_ACPI_TABLE	8
325 #define TAINT_WARN			9
326 #define TAINT_CRAP			10
327 
328 extern void dump_stack(void) __cold;
329 
330 enum {
331 	DUMP_PREFIX_NONE,
332 	DUMP_PREFIX_ADDRESS,
333 	DUMP_PREFIX_OFFSET
334 };
335 extern void hex_dump_to_buffer(const void *buf, size_t len,
336 				int rowsize, int groupsize,
337 				char *linebuf, size_t linebuflen, bool ascii);
338 extern void print_hex_dump(const char *level, const char *prefix_str,
339 				int prefix_type, int rowsize, int groupsize,
340 				const void *buf, size_t len, bool ascii);
341 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
342 			const void *buf, size_t len);
343 
344 extern const char hex_asc[];
345 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
346 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
347 
348 static inline char *pack_hex_byte(char *buf, u8 byte)
349 {
350 	*buf++ = hex_asc_hi(byte);
351 	*buf++ = hex_asc_lo(byte);
352 	return buf;
353 }
354 
355 #ifndef pr_fmt
356 #define pr_fmt(fmt) fmt
357 #endif
358 
359 #define pr_emerg(fmt, ...) \
360         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
361 #define pr_alert(fmt, ...) \
362         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
363 #define pr_crit(fmt, ...) \
364         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
365 #define pr_err(fmt, ...) \
366         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
367 #define pr_warning(fmt, ...) \
368         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
369 #define pr_notice(fmt, ...) \
370         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
371 #define pr_info(fmt, ...) \
372         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
373 
374 /* If you are writing a driver, please use dev_dbg instead */
375 #if defined(DEBUG)
376 #define pr_debug(fmt, ...) \
377 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
378 #elif defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
379 #define pr_debug(fmt, ...) do { \
380 	dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
381 	} while (0)
382 #else
383 #define pr_debug(fmt, ...) \
384 	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
385 #endif
386 
387 /*
388  * General tracing related utility functions - trace_printk(),
389  * tracing_on/tracing_off and tracing_start()/tracing_stop
390  *
391  * Use tracing_on/tracing_off when you want to quickly turn on or off
392  * tracing. It simply enables or disables the recording of the trace events.
393  * This also corresponds to the user space debugfs/tracing/tracing_on
394  * file, which gives a means for the kernel and userspace to interact.
395  * Place a tracing_off() in the kernel where you want tracing to end.
396  * From user space, examine the trace, and then echo 1 > tracing_on
397  * to continue tracing.
398  *
399  * tracing_stop/tracing_start has slightly more overhead. It is used
400  * by things like suspend to ram where disabling the recording of the
401  * trace is not enough, but tracing must actually stop because things
402  * like calling smp_processor_id() may crash the system.
403  *
404  * Most likely, you want to use tracing_on/tracing_off.
405  */
406 #ifdef CONFIG_RING_BUFFER
407 void tracing_on(void);
408 void tracing_off(void);
409 /* trace_off_permanent stops recording with no way to bring it back */
410 void tracing_off_permanent(void);
411 int tracing_is_on(void);
412 #else
413 static inline void tracing_on(void) { }
414 static inline void tracing_off(void) { }
415 static inline void tracing_off_permanent(void) { }
416 static inline int tracing_is_on(void) { return 0; }
417 #endif
418 #ifdef CONFIG_TRACING
419 extern void tracing_start(void);
420 extern void tracing_stop(void);
421 extern void ftrace_off_permanent(void);
422 
423 extern void
424 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
425 
426 static inline void __attribute__ ((format (printf, 1, 2)))
427 ____trace_printk_check_format(const char *fmt, ...)
428 {
429 }
430 #define __trace_printk_check_format(fmt, args...)			\
431 do {									\
432 	if (0)								\
433 		____trace_printk_check_format(fmt, ##args);		\
434 } while (0)
435 
436 /**
437  * trace_printk - printf formatting in the ftrace buffer
438  * @fmt: the printf format for printing
439  *
440  * Note: __trace_printk is an internal function for trace_printk and
441  *       the @ip is passed in via the trace_printk macro.
442  *
443  * This function allows a kernel developer to debug fast path sections
444  * that printk is not appropriate for. By scattering in various
445  * printk like tracing in the code, a developer can quickly see
446  * where problems are occurring.
447  *
448  * This is intended as a debugging tool for the developer only.
449  * Please refrain from leaving trace_printks scattered around in
450  * your code.
451  */
452 
453 #define trace_printk(fmt, args...)					\
454 do {									\
455 	__trace_printk_check_format(fmt, ##args);			\
456 	if (__builtin_constant_p(fmt)) {				\
457 		static const char *trace_printk_fmt			\
458 		  __attribute__((section("__trace_printk_fmt"))) =	\
459 			__builtin_constant_p(fmt) ? fmt : NULL;		\
460 									\
461 		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
462 	} else								\
463 		__trace_printk(_THIS_IP_, fmt, ##args);		\
464 } while (0)
465 
466 extern int
467 __trace_bprintk(unsigned long ip, const char *fmt, ...)
468 	__attribute__ ((format (printf, 2, 3)));
469 
470 extern int
471 __trace_printk(unsigned long ip, const char *fmt, ...)
472 	__attribute__ ((format (printf, 2, 3)));
473 
474 /*
475  * The double __builtin_constant_p is because gcc will give us an error
476  * if we try to allocate the static variable to fmt if it is not a
477  * constant. Even with the outer if statement.
478  */
479 #define ftrace_vprintk(fmt, vargs)					\
480 do {									\
481 	if (__builtin_constant_p(fmt)) {				\
482 		static const char *trace_printk_fmt			\
483 		  __attribute__((section("__trace_printk_fmt"))) =	\
484 			__builtin_constant_p(fmt) ? fmt : NULL;		\
485 									\
486 		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
487 	} else								\
488 		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
489 } while (0)
490 
491 extern int
492 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
493 
494 extern int
495 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
496 
497 extern void ftrace_dump(void);
498 #else
499 static inline void
500 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
501 static inline int
502 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
503 
504 static inline void tracing_start(void) { }
505 static inline void tracing_stop(void) { }
506 static inline void ftrace_off_permanent(void) { }
507 static inline int
508 trace_printk(const char *fmt, ...)
509 {
510 	return 0;
511 }
512 static inline int
513 ftrace_vprintk(const char *fmt, va_list ap)
514 {
515 	return 0;
516 }
517 static inline void ftrace_dump(void) { }
518 #endif /* CONFIG_TRACING */
519 
520 /*
521  *      Display an IP address in readable format.
522  */
523 
524 #define NIPQUAD(addr) \
525 	((unsigned char *)&addr)[0], \
526 	((unsigned char *)&addr)[1], \
527 	((unsigned char *)&addr)[2], \
528 	((unsigned char *)&addr)[3]
529 #define NIPQUAD_FMT "%u.%u.%u.%u"
530 
531 #if defined(__LITTLE_ENDIAN)
532 #define HIPQUAD(addr) \
533 	((unsigned char *)&addr)[3], \
534 	((unsigned char *)&addr)[2], \
535 	((unsigned char *)&addr)[1], \
536 	((unsigned char *)&addr)[0]
537 #elif defined(__BIG_ENDIAN)
538 #define HIPQUAD	NIPQUAD
539 #else
540 #error "Please fix asm/byteorder.h"
541 #endif /* __LITTLE_ENDIAN */
542 
543 /*
544  * min()/max()/clamp() macros that also do
545  * strict type-checking.. See the
546  * "unnecessary" pointer comparison.
547  */
548 #define min(x, y) ({				\
549 	typeof(x) _min1 = (x);			\
550 	typeof(y) _min2 = (y);			\
551 	(void) (&_min1 == &_min2);		\
552 	_min1 < _min2 ? _min1 : _min2; })
553 
554 #define max(x, y) ({				\
555 	typeof(x) _max1 = (x);			\
556 	typeof(y) _max2 = (y);			\
557 	(void) (&_max1 == &_max2);		\
558 	_max1 > _max2 ? _max1 : _max2; })
559 
560 /**
561  * clamp - return a value clamped to a given range with strict typechecking
562  * @val: current value
563  * @min: minimum allowable value
564  * @max: maximum allowable value
565  *
566  * This macro does strict typechecking of min/max to make sure they are of the
567  * same type as val.  See the unnecessary pointer comparisons.
568  */
569 #define clamp(val, min, max) ({			\
570 	typeof(val) __val = (val);		\
571 	typeof(min) __min = (min);		\
572 	typeof(max) __max = (max);		\
573 	(void) (&__val == &__min);		\
574 	(void) (&__val == &__max);		\
575 	__val = __val < __min ? __min: __val;	\
576 	__val > __max ? __max: __val; })
577 
578 /*
579  * ..and if you can't take the strict
580  * types, you can specify one yourself.
581  *
582  * Or not use min/max/clamp at all, of course.
583  */
584 #define min_t(type, x, y) ({			\
585 	type __min1 = (x);			\
586 	type __min2 = (y);			\
587 	__min1 < __min2 ? __min1: __min2; })
588 
589 #define max_t(type, x, y) ({			\
590 	type __max1 = (x);			\
591 	type __max2 = (y);			\
592 	__max1 > __max2 ? __max1: __max2; })
593 
594 /**
595  * clamp_t - return a value clamped to a given range using a given type
596  * @type: the type of variable to use
597  * @val: current value
598  * @min: minimum allowable value
599  * @max: maximum allowable value
600  *
601  * This macro does no typechecking and uses temporary variables of type
602  * 'type' to make all the comparisons.
603  */
604 #define clamp_t(type, val, min, max) ({		\
605 	type __val = (val);			\
606 	type __min = (min);			\
607 	type __max = (max);			\
608 	__val = __val < __min ? __min: __val;	\
609 	__val > __max ? __max: __val; })
610 
611 /**
612  * clamp_val - return a value clamped to a given range using val's type
613  * @val: current value
614  * @min: minimum allowable value
615  * @max: maximum allowable value
616  *
617  * This macro does no typechecking and uses temporary variables of whatever
618  * type the input argument 'val' is.  This is useful when val is an unsigned
619  * type and min and max are literals that will otherwise be assigned a signed
620  * integer type.
621  */
622 #define clamp_val(val, min, max) ({		\
623 	typeof(val) __val = (val);		\
624 	typeof(val) __min = (min);		\
625 	typeof(val) __max = (max);		\
626 	__val = __val < __min ? __min: __val;	\
627 	__val > __max ? __max: __val; })
628 
629 
630 /*
631  * swap - swap value of @a and @b
632  */
633 #define swap(a, b) \
634 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
635 
636 /**
637  * container_of - cast a member of a structure out to the containing structure
638  * @ptr:	the pointer to the member.
639  * @type:	the type of the container struct this is embedded in.
640  * @member:	the name of the member within the struct.
641  *
642  */
643 #define container_of(ptr, type, member) ({			\
644 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
645 	(type *)( (char *)__mptr - offsetof(type,member) );})
646 
647 struct sysinfo;
648 extern int do_sysinfo(struct sysinfo *info);
649 
650 #endif /* __KERNEL__ */
651 
652 #define SI_LOAD_SHIFT	16
653 struct sysinfo {
654 	long uptime;			/* Seconds since boot */
655 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
656 	unsigned long totalram;		/* Total usable main memory size */
657 	unsigned long freeram;		/* Available memory size */
658 	unsigned long sharedram;	/* Amount of shared memory */
659 	unsigned long bufferram;	/* Memory used by buffers */
660 	unsigned long totalswap;	/* Total swap space size */
661 	unsigned long freeswap;		/* swap space still available */
662 	unsigned short procs;		/* Number of current processes */
663 	unsigned short pad;		/* explicit padding for m68k */
664 	unsigned long totalhigh;	/* Total high memory size */
665 	unsigned long freehigh;		/* Available high memory size */
666 	unsigned int mem_unit;		/* Memory unit size in bytes */
667 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
668 };
669 
670 /* Force a compilation error if condition is true */
671 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
672 
673 /* Force a compilation error if condition is true, but also produce a
674    result (of value 0 and type size_t), so the expression can be used
675    e.g. in a structure initializer (or where-ever else comma expressions
676    aren't permitted). */
677 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
678 
679 /* Trap pasters of __FUNCTION__ at compile-time */
680 #define __FUNCTION__ (__func__)
681 
682 /* This helps us to avoid #ifdef CONFIG_NUMA */
683 #ifdef CONFIG_NUMA
684 #define NUMA_BUILD 1
685 #else
686 #define NUMA_BUILD 0
687 #endif
688 
689 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
690 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
691 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
692 #endif
693 
694 #endif
695