xref: /linux-6.15/include/linux/kernel.h (revision ff10fca5)
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 /*
5  * 'kernel.h' contains some often-used function prototypes etc
6  */
7 #define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
8 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
9 
10 #ifdef __KERNEL__
11 
12 #include <stdarg.h>
13 #include <linux/linkage.h>
14 #include <linux/stddef.h>
15 #include <linux/types.h>
16 #include <linux/compiler.h>
17 #include <linux/bitops.h>
18 #include <linux/log2.h>
19 #include <linux/typecheck.h>
20 #include <linux/dynamic_debug.h>
21 #include <asm/byteorder.h>
22 #include <asm/bug.h>
23 
24 extern const char linux_banner[];
25 extern const char linux_proc_banner[];
26 
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)
39 
40 #define STACK_MAGIC	0xdeadbeef
41 
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)
46 
47 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
48 
49 /*
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.
54  */
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))
58 
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) (					\
62 {							\
63 	typeof(y) __y = y;				\
64 	(((x) + (__y - 1)) / __y) * __y;		\
65 }							\
66 )
67 #define rounddown(x, y) (				\
68 {							\
69 	typeof(x) __x = (x);				\
70 	__x - (__x % (y));				\
71 }							\
72 )
73 #define DIV_ROUND_CLOSEST(x, divisor)(			\
74 {							\
75 	typeof(divisor) __divisor = divisor;		\
76 	(((x) + ((__divisor) / 2)) / (__divisor));	\
77 }							\
78 )
79 
80 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
81 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
82 
83 #ifdef CONFIG_LBDAF
84 # include <asm/div64.h>
85 # define sector_div(a, b) do_div(a, b)
86 #else
87 # define sector_div(n, b)( \
88 { \
89 	int _res; \
90 	_res = (n) % (b); \
91 	(n) /= (b); \
92 	_res; \
93 } \
94 )
95 #endif
96 
97 /**
98  * upper_32_bits - return bits 32-63 of a number
99  * @n: the number we're accessing
100  *
101  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
102  * the "right shift count >= width of type" warning when that quantity is
103  * 32-bits.
104  */
105 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
106 
107 /**
108  * lower_32_bits - return bits 0-31 of a number
109  * @n: the number we're accessing
110  */
111 #define lower_32_bits(n) ((u32)(n))
112 
113 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
114 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
115 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
116 #define	KERN_ERR	"<3>"	/* error conditions			*/
117 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
118 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
119 #define	KERN_INFO	"<6>"	/* informational			*/
120 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
121 
122 /* Use the default kernel loglevel */
123 #define KERN_DEFAULT	"<d>"
124 /*
125  * Annotation for a "continued" line of log printout (only done after a
126  * line that had no enclosing \n). Only to be used by core/arch code
127  * during early bootup (a continued line is not SMP-safe otherwise).
128  */
129 #define	KERN_CONT	"<c>"
130 
131 extern int console_printk[];
132 
133 #define console_loglevel (console_printk[0])
134 #define default_message_loglevel (console_printk[1])
135 #define minimum_console_loglevel (console_printk[2])
136 #define default_console_loglevel (console_printk[3])
137 
138 struct completion;
139 struct pt_regs;
140 struct user;
141 
142 #ifdef CONFIG_PREEMPT_VOLUNTARY
143 extern int _cond_resched(void);
144 # define might_resched() _cond_resched()
145 #else
146 # define might_resched() do { } while (0)
147 #endif
148 
149 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
150   void __might_sleep(const char *file, int line, int preempt_offset);
151 /**
152  * might_sleep - annotation for functions that can sleep
153  *
154  * this macro will print a stack trace if it is executed in an atomic
155  * context (spinlock, irq-handler, ...).
156  *
157  * This is a useful debugging help to be able to catch problems early and not
158  * be bitten later when the calling function happens to sleep when it is not
159  * supposed to.
160  */
161 # define might_sleep() \
162 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
163 #else
164   static inline void __might_sleep(const char *file, int line,
165 				   int preempt_offset) { }
166 # define might_sleep() do { might_resched(); } while (0)
167 #endif
168 
169 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
170 
171 #define abs(x) ({				\
172 		long __x = (x);			\
173 		(__x < 0) ? -__x : __x;		\
174 	})
175 
176 #ifdef CONFIG_PROVE_LOCKING
177 void might_fault(void);
178 #else
179 static inline void might_fault(void)
180 {
181 	might_sleep();
182 }
183 #endif
184 
185 struct va_format {
186 	const char *fmt;
187 	va_list *va;
188 };
189 
190 extern struct atomic_notifier_head panic_notifier_list;
191 extern long (*panic_blink)(int state);
192 NORET_TYPE void panic(const char * fmt, ...)
193 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
194 extern void oops_enter(void);
195 extern void oops_exit(void);
196 void print_oops_end_marker(void);
197 extern int oops_may_print(void);
198 NORET_TYPE void do_exit(long error_code)
199 	ATTRIB_NORET;
200 NORET_TYPE void complete_and_exit(struct completion *, long)
201 	ATTRIB_NORET;
202 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
203 extern long simple_strtol(const char *,char **,unsigned int);
204 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
205 extern long long simple_strtoll(const char *,char **,unsigned int);
206 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
207 extern int strict_strtol(const char *, unsigned int, long *);
208 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
209 extern int strict_strtoll(const char *, unsigned int, long long *);
210 extern int sprintf(char * buf, const char * fmt, ...)
211 	__attribute__ ((format (printf, 2, 3)));
212 extern int vsprintf(char *buf, const char *, va_list)
213 	__attribute__ ((format (printf, 2, 0)));
214 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
215 	__attribute__ ((format (printf, 3, 4)));
216 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
217 	__attribute__ ((format (printf, 3, 0)));
218 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
219 	__attribute__ ((format (printf, 3, 4)));
220 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
221 	__attribute__ ((format (printf, 3, 0)));
222 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
223 	__attribute__ ((format (printf, 2, 3)));
224 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
225 
226 extern int sscanf(const char *, const char *, ...)
227 	__attribute__ ((format (scanf, 2, 3)));
228 extern int vsscanf(const char *, const char *, va_list)
229 	__attribute__ ((format (scanf, 2, 0)));
230 
231 extern int get_option(char **str, int *pint);
232 extern char *get_options(const char *str, int nints, int *ints);
233 extern unsigned long long memparse(const char *ptr, char **retptr);
234 
235 extern int core_kernel_text(unsigned long addr);
236 extern int __kernel_text_address(unsigned long addr);
237 extern int kernel_text_address(unsigned long addr);
238 extern int func_ptr_is_kernel_text(void *ptr);
239 
240 struct pid;
241 extern struct pid *session_of_pgrp(struct pid *pgrp);
242 
243 /*
244  * FW_BUG
245  * Add this to a message where you are sure the firmware is buggy or behaves
246  * really stupid or out of spec. Be aware that the responsible BIOS developer
247  * should be able to fix this issue or at least get a concrete idea of the
248  * problem by reading your message without the need of looking at the kernel
249  * code.
250  *
251  * Use it for definite and high priority BIOS bugs.
252  *
253  * FW_WARN
254  * Use it for not that clear (e.g. could the kernel messed up things already?)
255  * and medium priority BIOS bugs.
256  *
257  * FW_INFO
258  * Use this one if you want to tell the user or vendor about something
259  * suspicious, but generally harmless related to the firmware.
260  *
261  * Use it for information or very low priority BIOS bugs.
262  */
263 #define FW_BUG		"[Firmware Bug]: "
264 #define FW_WARN		"[Firmware Warn]: "
265 #define FW_INFO		"[Firmware Info]: "
266 
267 /*
268  * HW_ERR
269  * Add this to a message for hardware errors, so that user can report
270  * it to hardware vendor instead of LKML or software vendor.
271  */
272 #define HW_ERR		"[Hardware Error]: "
273 
274 #ifdef CONFIG_PRINTK
275 asmlinkage int vprintk(const char *fmt, va_list args)
276 	__attribute__ ((format (printf, 1, 0)));
277 asmlinkage int printk(const char * fmt, ...)
278 	__attribute__ ((format (printf, 1, 2))) __cold;
279 
280 extern int __printk_ratelimit(const char *func);
281 #define printk_ratelimit() __printk_ratelimit(__func__)
282 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
283 				   unsigned int interval_msec);
284 
285 extern int printk_delay_msec;
286 
287 /*
288  * Print a one-time message (analogous to WARN_ONCE() et al):
289  */
290 #define printk_once(x...) ({			\
291 	static bool __print_once;		\
292 						\
293 	if (!__print_once) {			\
294 		__print_once = true;		\
295 		printk(x);			\
296 	}					\
297 })
298 
299 void log_buf_kexec_setup(void);
300 #else
301 static inline int vprintk(const char *s, va_list args)
302 	__attribute__ ((format (printf, 1, 0)));
303 static inline int vprintk(const char *s, va_list args) { return 0; }
304 static inline int printk(const char *s, ...)
305 	__attribute__ ((format (printf, 1, 2)));
306 static inline int __cold printk(const char *s, ...) { return 0; }
307 static inline int printk_ratelimit(void) { return 0; }
308 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
309 					  unsigned int interval_msec)	\
310 		{ return false; }
311 
312 /* No effect, but we still get type checking even in the !PRINTK case: */
313 #define printk_once(x...) printk(x)
314 
315 static inline void log_buf_kexec_setup(void)
316 {
317 }
318 #endif
319 
320 /*
321  * Dummy printk for disabled debugging statements to use whilst maintaining
322  * gcc's format and side-effect checking.
323  */
324 static inline __attribute__ ((format (printf, 1, 2)))
325 int no_printk(const char *s, ...) { return 0; }
326 
327 extern int printk_needs_cpu(int cpu);
328 extern void printk_tick(void);
329 
330 extern void asmlinkage __attribute__((format(printf, 1, 2)))
331 	early_printk(const char *fmt, ...);
332 
333 unsigned long int_sqrt(unsigned long);
334 
335 static inline void console_silent(void)
336 {
337 	console_loglevel = 0;
338 }
339 
340 static inline void console_verbose(void)
341 {
342 	if (console_loglevel)
343 		console_loglevel = 15;
344 }
345 
346 extern void bust_spinlocks(int yes);
347 extern void wake_up_klogd(void);
348 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
349 extern int panic_timeout;
350 extern int panic_on_oops;
351 extern int panic_on_unrecovered_nmi;
352 extern int panic_on_io_nmi;
353 extern const char *print_tainted(void);
354 extern void add_taint(unsigned flag);
355 extern int test_taint(unsigned flag);
356 extern unsigned long get_taint(void);
357 extern int root_mountflags;
358 
359 /* Values used for system_state */
360 extern enum system_states {
361 	SYSTEM_BOOTING,
362 	SYSTEM_RUNNING,
363 	SYSTEM_HALT,
364 	SYSTEM_POWER_OFF,
365 	SYSTEM_RESTART,
366 	SYSTEM_SUSPEND_DISK,
367 } system_state;
368 
369 #define TAINT_PROPRIETARY_MODULE	0
370 #define TAINT_FORCED_MODULE		1
371 #define TAINT_UNSAFE_SMP		2
372 #define TAINT_FORCED_RMMOD		3
373 #define TAINT_MACHINE_CHECK		4
374 #define TAINT_BAD_PAGE			5
375 #define TAINT_USER			6
376 #define TAINT_DIE			7
377 #define TAINT_OVERRIDDEN_ACPI_TABLE	8
378 #define TAINT_WARN			9
379 #define TAINT_CRAP			10
380 #define TAINT_FIRMWARE_WORKAROUND	11
381 
382 extern void dump_stack(void) __cold;
383 
384 enum {
385 	DUMP_PREFIX_NONE,
386 	DUMP_PREFIX_ADDRESS,
387 	DUMP_PREFIX_OFFSET
388 };
389 extern void hex_dump_to_buffer(const void *buf, size_t len,
390 				int rowsize, int groupsize,
391 				char *linebuf, size_t linebuflen, bool ascii);
392 extern void print_hex_dump(const char *level, const char *prefix_str,
393 				int prefix_type, int rowsize, int groupsize,
394 				const void *buf, size_t len, bool ascii);
395 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
396 			const void *buf, size_t len);
397 
398 extern const char hex_asc[];
399 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
400 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
401 
402 static inline char *pack_hex_byte(char *buf, u8 byte)
403 {
404 	*buf++ = hex_asc_hi(byte);
405 	*buf++ = hex_asc_lo(byte);
406 	return buf;
407 }
408 
409 extern int hex_to_bin(char ch);
410 
411 #ifndef pr_fmt
412 #define pr_fmt(fmt) fmt
413 #endif
414 
415 #define pr_emerg(fmt, ...) \
416         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
417 #define pr_alert(fmt, ...) \
418         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
419 #define pr_crit(fmt, ...) \
420         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
421 #define pr_err(fmt, ...) \
422         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
423 #define pr_warning(fmt, ...) \
424         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
425 #define pr_warn pr_warning
426 #define pr_notice(fmt, ...) \
427         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
428 #define pr_info(fmt, ...) \
429         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
430 #define pr_cont(fmt, ...) \
431 	printk(KERN_CONT fmt, ##__VA_ARGS__)
432 
433 /* pr_devel() should produce zero code unless DEBUG is defined */
434 #ifdef DEBUG
435 #define pr_devel(fmt, ...) \
436 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
437 #else
438 #define pr_devel(fmt, ...) \
439 	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
440 #endif
441 
442 /* If you are writing a driver, please use dev_dbg instead */
443 #if defined(DEBUG)
444 #define pr_debug(fmt, ...) \
445 	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
446 #elif defined(CONFIG_DYNAMIC_DEBUG)
447 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
448 #define pr_debug(fmt, ...) \
449 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
450 #else
451 #define pr_debug(fmt, ...) \
452 	({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
453 #endif
454 
455 /*
456  * ratelimited messages with local ratelimit_state,
457  * no local ratelimit_state used in the !PRINTK case
458  */
459 #ifdef CONFIG_PRINTK
460 #define printk_ratelimited(fmt, ...)  ({				\
461 	static DEFINE_RATELIMIT_STATE(_rs,				\
462 				      DEFAULT_RATELIMIT_INTERVAL,	\
463 				      DEFAULT_RATELIMIT_BURST);		\
464 									\
465 	if (__ratelimit(&_rs))						\
466 		printk(fmt, ##__VA_ARGS__);				\
467 })
468 #else
469 /* No effect, but we still get type checking even in the !PRINTK case: */
470 #define printk_ratelimited printk
471 #endif
472 
473 #define pr_emerg_ratelimited(fmt, ...) \
474 	printk_ratelimited(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
475 #define pr_alert_ratelimited(fmt, ...) \
476 	printk_ratelimited(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
477 #define pr_crit_ratelimited(fmt, ...) \
478 	printk_ratelimited(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
479 #define pr_err_ratelimited(fmt, ...) \
480 	printk_ratelimited(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
481 #define pr_warning_ratelimited(fmt, ...) \
482 	printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
483 #define pr_warn_ratelimited pr_warning_ratelimited
484 #define pr_notice_ratelimited(fmt, ...) \
485 	printk_ratelimited(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
486 #define pr_info_ratelimited(fmt, ...) \
487 	printk_ratelimited(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
488 /* no pr_cont_ratelimited, don't do that... */
489 /* If you are writing a driver, please use dev_dbg instead */
490 #if defined(DEBUG)
491 #define pr_debug_ratelimited(fmt, ...) \
492 	printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
493 #else
494 #define pr_debug_ratelimited(fmt, ...) \
495 	({ if (0) printk_ratelimited(KERN_DEBUG pr_fmt(fmt), \
496 				     ##__VA_ARGS__); 0; })
497 #endif
498 
499 /*
500  * General tracing related utility functions - trace_printk(),
501  * tracing_on/tracing_off and tracing_start()/tracing_stop
502  *
503  * Use tracing_on/tracing_off when you want to quickly turn on or off
504  * tracing. It simply enables or disables the recording of the trace events.
505  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
506  * file, which gives a means for the kernel and userspace to interact.
507  * Place a tracing_off() in the kernel where you want tracing to end.
508  * From user space, examine the trace, and then echo 1 > tracing_on
509  * to continue tracing.
510  *
511  * tracing_stop/tracing_start has slightly more overhead. It is used
512  * by things like suspend to ram where disabling the recording of the
513  * trace is not enough, but tracing must actually stop because things
514  * like calling smp_processor_id() may crash the system.
515  *
516  * Most likely, you want to use tracing_on/tracing_off.
517  */
518 #ifdef CONFIG_RING_BUFFER
519 void tracing_on(void);
520 void tracing_off(void);
521 /* trace_off_permanent stops recording with no way to bring it back */
522 void tracing_off_permanent(void);
523 int tracing_is_on(void);
524 #else
525 static inline void tracing_on(void) { }
526 static inline void tracing_off(void) { }
527 static inline void tracing_off_permanent(void) { }
528 static inline int tracing_is_on(void) { return 0; }
529 #endif
530 
531 enum ftrace_dump_mode {
532 	DUMP_NONE,
533 	DUMP_ALL,
534 	DUMP_ORIG,
535 };
536 
537 #ifdef CONFIG_TRACING
538 extern void tracing_start(void);
539 extern void tracing_stop(void);
540 extern void ftrace_off_permanent(void);
541 
542 static inline void __attribute__ ((format (printf, 1, 2)))
543 ____trace_printk_check_format(const char *fmt, ...)
544 {
545 }
546 #define __trace_printk_check_format(fmt, args...)			\
547 do {									\
548 	if (0)								\
549 		____trace_printk_check_format(fmt, ##args);		\
550 } while (0)
551 
552 /**
553  * trace_printk - printf formatting in the ftrace buffer
554  * @fmt: the printf format for printing
555  *
556  * Note: __trace_printk is an internal function for trace_printk and
557  *       the @ip is passed in via the trace_printk macro.
558  *
559  * This function allows a kernel developer to debug fast path sections
560  * that printk is not appropriate for. By scattering in various
561  * printk like tracing in the code, a developer can quickly see
562  * where problems are occurring.
563  *
564  * This is intended as a debugging tool for the developer only.
565  * Please refrain from leaving trace_printks scattered around in
566  * your code.
567  */
568 
569 #define trace_printk(fmt, args...)					\
570 do {									\
571 	__trace_printk_check_format(fmt, ##args);			\
572 	if (__builtin_constant_p(fmt)) {				\
573 		static const char *trace_printk_fmt			\
574 		  __attribute__((section("__trace_printk_fmt"))) =	\
575 			__builtin_constant_p(fmt) ? fmt : NULL;		\
576 									\
577 		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
578 	} else								\
579 		__trace_printk(_THIS_IP_, fmt, ##args);		\
580 } while (0)
581 
582 extern int
583 __trace_bprintk(unsigned long ip, const char *fmt, ...)
584 	__attribute__ ((format (printf, 2, 3)));
585 
586 extern int
587 __trace_printk(unsigned long ip, const char *fmt, ...)
588 	__attribute__ ((format (printf, 2, 3)));
589 
590 extern void trace_dump_stack(void);
591 
592 /*
593  * The double __builtin_constant_p is because gcc will give us an error
594  * if we try to allocate the static variable to fmt if it is not a
595  * constant. Even with the outer if statement.
596  */
597 #define ftrace_vprintk(fmt, vargs)					\
598 do {									\
599 	if (__builtin_constant_p(fmt)) {				\
600 		static const char *trace_printk_fmt			\
601 		  __attribute__((section("__trace_printk_fmt"))) =	\
602 			__builtin_constant_p(fmt) ? fmt : NULL;		\
603 									\
604 		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
605 	} else								\
606 		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
607 } while (0)
608 
609 extern int
610 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
611 
612 extern int
613 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
614 
615 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
616 #else
617 static inline int
618 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
619 
620 static inline void tracing_start(void) { }
621 static inline void tracing_stop(void) { }
622 static inline void ftrace_off_permanent(void) { }
623 static inline void trace_dump_stack(void) { }
624 static inline int
625 trace_printk(const char *fmt, ...)
626 {
627 	return 0;
628 }
629 static inline int
630 ftrace_vprintk(const char *fmt, va_list ap)
631 {
632 	return 0;
633 }
634 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
635 #endif /* CONFIG_TRACING */
636 
637 /*
638  * min()/max()/clamp() macros that also do
639  * strict type-checking.. See the
640  * "unnecessary" pointer comparison.
641  */
642 #define min(x, y) ({				\
643 	typeof(x) _min1 = (x);			\
644 	typeof(y) _min2 = (y);			\
645 	(void) (&_min1 == &_min2);		\
646 	_min1 < _min2 ? _min1 : _min2; })
647 
648 #define max(x, y) ({				\
649 	typeof(x) _max1 = (x);			\
650 	typeof(y) _max2 = (y);			\
651 	(void) (&_max1 == &_max2);		\
652 	_max1 > _max2 ? _max1 : _max2; })
653 
654 /**
655  * clamp - return a value clamped to a given range with strict typechecking
656  * @val: current value
657  * @min: minimum allowable value
658  * @max: maximum allowable value
659  *
660  * This macro does strict typechecking of min/max to make sure they are of the
661  * same type as val.  See the unnecessary pointer comparisons.
662  */
663 #define clamp(val, min, max) ({			\
664 	typeof(val) __val = (val);		\
665 	typeof(min) __min = (min);		\
666 	typeof(max) __max = (max);		\
667 	(void) (&__val == &__min);		\
668 	(void) (&__val == &__max);		\
669 	__val = __val < __min ? __min: __val;	\
670 	__val > __max ? __max: __val; })
671 
672 /*
673  * ..and if you can't take the strict
674  * types, you can specify one yourself.
675  *
676  * Or not use min/max/clamp at all, of course.
677  */
678 #define min_t(type, x, y) ({			\
679 	type __min1 = (x);			\
680 	type __min2 = (y);			\
681 	__min1 < __min2 ? __min1: __min2; })
682 
683 #define max_t(type, x, y) ({			\
684 	type __max1 = (x);			\
685 	type __max2 = (y);			\
686 	__max1 > __max2 ? __max1: __max2; })
687 
688 /**
689  * clamp_t - return a value clamped to a given range using a given type
690  * @type: the type of variable to use
691  * @val: current value
692  * @min: minimum allowable value
693  * @max: maximum allowable value
694  *
695  * This macro does no typechecking and uses temporary variables of type
696  * 'type' to make all the comparisons.
697  */
698 #define clamp_t(type, val, min, max) ({		\
699 	type __val = (val);			\
700 	type __min = (min);			\
701 	type __max = (max);			\
702 	__val = __val < __min ? __min: __val;	\
703 	__val > __max ? __max: __val; })
704 
705 /**
706  * clamp_val - return a value clamped to a given range using val's type
707  * @val: current value
708  * @min: minimum allowable value
709  * @max: maximum allowable value
710  *
711  * This macro does no typechecking and uses temporary variables of whatever
712  * type the input argument 'val' is.  This is useful when val is an unsigned
713  * type and min and max are literals that will otherwise be assigned a signed
714  * integer type.
715  */
716 #define clamp_val(val, min, max) ({		\
717 	typeof(val) __val = (val);		\
718 	typeof(val) __min = (min);		\
719 	typeof(val) __max = (max);		\
720 	__val = __val < __min ? __min: __val;	\
721 	__val > __max ? __max: __val; })
722 
723 
724 /*
725  * swap - swap value of @a and @b
726  */
727 #define swap(a, b) \
728 	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
729 
730 /**
731  * container_of - cast a member of a structure out to the containing structure
732  * @ptr:	the pointer to the member.
733  * @type:	the type of the container struct this is embedded in.
734  * @member:	the name of the member within the struct.
735  *
736  */
737 #define container_of(ptr, type, member) ({			\
738 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
739 	(type *)( (char *)__mptr - offsetof(type,member) );})
740 
741 struct sysinfo;
742 extern int do_sysinfo(struct sysinfo *info);
743 
744 #endif /* __KERNEL__ */
745 
746 #define SI_LOAD_SHIFT	16
747 struct sysinfo {
748 	long uptime;			/* Seconds since boot */
749 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
750 	unsigned long totalram;		/* Total usable main memory size */
751 	unsigned long freeram;		/* Available memory size */
752 	unsigned long sharedram;	/* Amount of shared memory */
753 	unsigned long bufferram;	/* Memory used by buffers */
754 	unsigned long totalswap;	/* Total swap space size */
755 	unsigned long freeswap;		/* swap space still available */
756 	unsigned short procs;		/* Number of current processes */
757 	unsigned short pad;		/* explicit padding for m68k */
758 	unsigned long totalhigh;	/* Total high memory size */
759 	unsigned long freehigh;		/* Available high memory size */
760 	unsigned int mem_unit;		/* Memory unit size in bytes */
761 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
762 };
763 
764 /* Force a compilation error if condition is true */
765 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
766 
767 /* Force a compilation error if condition is constant and true */
768 #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
769 
770 /* Force a compilation error if a constant expression is not a power of 2 */
771 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
772 	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
773 
774 /* Force a compilation error if condition is true, but also produce a
775    result (of value 0 and type size_t), so the expression can be used
776    e.g. in a structure initializer (or where-ever else comma expressions
777    aren't permitted). */
778 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
779 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
780 
781 /* Trap pasters of __FUNCTION__ at compile-time */
782 #define __FUNCTION__ (__func__)
783 
784 /* This helps us to avoid #ifdef CONFIG_NUMA */
785 #ifdef CONFIG_NUMA
786 #define NUMA_BUILD 1
787 #else
788 #define NUMA_BUILD 0
789 #endif
790 
791 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
792 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
793 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
794 #endif
795 
796 #endif
797