xref: /linux-6.15/include/linux/kernel.h (revision dfed0449)
11da177e4SLinus Torvalds #ifndef _LINUX_KERNEL_H
21da177e4SLinus Torvalds #define _LINUX_KERNEL_H
31da177e4SLinus Torvalds 
41da177e4SLinus Torvalds /*
51da177e4SLinus Torvalds  * 'kernel.h' contains some often-used function prototypes etc
61da177e4SLinus Torvalds  */
71da177e4SLinus Torvalds 
81da177e4SLinus Torvalds #ifdef __KERNEL__
91da177e4SLinus Torvalds 
101da177e4SLinus Torvalds #include <stdarg.h>
111da177e4SLinus Torvalds #include <linux/linkage.h>
121da177e4SLinus Torvalds #include <linux/stddef.h>
131da177e4SLinus Torvalds #include <linux/types.h>
141da177e4SLinus Torvalds #include <linux/compiler.h>
151da177e4SLinus Torvalds #include <linux/bitops.h>
161da177e4SLinus Torvalds #include <asm/byteorder.h>
171da177e4SLinus Torvalds #include <asm/bug.h>
181da177e4SLinus Torvalds 
191da177e4SLinus Torvalds extern const char linux_banner[];
201da177e4SLinus Torvalds 
211da177e4SLinus Torvalds #define INT_MAX		((int)(~0U>>1))
221da177e4SLinus Torvalds #define INT_MIN		(-INT_MAX - 1)
231da177e4SLinus Torvalds #define UINT_MAX	(~0U)
241da177e4SLinus Torvalds #define LONG_MAX	((long)(~0UL>>1))
251da177e4SLinus Torvalds #define LONG_MIN	(-LONG_MAX - 1)
261da177e4SLinus Torvalds #define ULONG_MAX	(~0UL)
271da177e4SLinus Torvalds 
281da177e4SLinus Torvalds #define STACK_MAGIC	0xdeadbeef
291da177e4SLinus Torvalds 
301da177e4SLinus Torvalds #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
311da177e4SLinus Torvalds #define ALIGN(x,a) (((x)+(a)-1)&~((a)-1))
321da177e4SLinus Torvalds 
331da177e4SLinus Torvalds #define	KERN_EMERG	"<0>"	/* system is unusable			*/
341da177e4SLinus Torvalds #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
351da177e4SLinus Torvalds #define	KERN_CRIT	"<2>"	/* critical conditions			*/
361da177e4SLinus Torvalds #define	KERN_ERR	"<3>"	/* error conditions			*/
371da177e4SLinus Torvalds #define	KERN_WARNING	"<4>"	/* warning conditions			*/
381da177e4SLinus Torvalds #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
391da177e4SLinus Torvalds #define	KERN_INFO	"<6>"	/* informational			*/
401da177e4SLinus Torvalds #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
411da177e4SLinus Torvalds 
421da177e4SLinus Torvalds extern int console_printk[];
431da177e4SLinus Torvalds 
441da177e4SLinus Torvalds #define console_loglevel (console_printk[0])
451da177e4SLinus Torvalds #define default_message_loglevel (console_printk[1])
461da177e4SLinus Torvalds #define minimum_console_loglevel (console_printk[2])
471da177e4SLinus Torvalds #define default_console_loglevel (console_printk[3])
481da177e4SLinus Torvalds 
491da177e4SLinus Torvalds struct completion;
501da177e4SLinus Torvalds 
511da177e4SLinus Torvalds /**
521da177e4SLinus Torvalds  * might_sleep - annotation for functions that can sleep
531da177e4SLinus Torvalds  *
541da177e4SLinus Torvalds  * this macro will print a stack trace if it is executed in an atomic
551da177e4SLinus Torvalds  * context (spinlock, irq-handler, ...).
561da177e4SLinus Torvalds  *
571da177e4SLinus Torvalds  * This is a useful debugging help to be able to catch problems early and not
581da177e4SLinus Torvalds  * be biten later when the calling function happens to sleep when it is not
591da177e4SLinus Torvalds  * supposed to.
601da177e4SLinus Torvalds  */
61f8cbd99bSIngo Molnar #ifdef CONFIG_PREEMPT_VOLUNTARY
62f8cbd99bSIngo Molnar extern int cond_resched(void);
63f8cbd99bSIngo Molnar # define might_resched() cond_resched()
641da177e4SLinus Torvalds #else
65f8cbd99bSIngo Molnar # define might_resched() do { } while (0)
661da177e4SLinus Torvalds #endif
671da177e4SLinus Torvalds 
68f8cbd99bSIngo Molnar #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
69f8cbd99bSIngo Molnar   void __might_sleep(char *file, int line);
70f8cbd99bSIngo Molnar # define might_sleep() \
71f8cbd99bSIngo Molnar 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
72f8cbd99bSIngo Molnar #else
73f8cbd99bSIngo Molnar # define might_sleep() do { might_resched(); } while (0)
74f8cbd99bSIngo Molnar #endif
75f8cbd99bSIngo Molnar 
76f8cbd99bSIngo Molnar #define might_sleep_if(cond) do { if (unlikely(cond)) might_sleep(); } while (0)
77f8cbd99bSIngo Molnar 
781da177e4SLinus Torvalds #define abs(x) ({				\
791da177e4SLinus Torvalds 		int __x = (x);			\
801da177e4SLinus Torvalds 		(__x < 0) ? -__x : __x;		\
811da177e4SLinus Torvalds 	})
821da177e4SLinus Torvalds 
831da177e4SLinus Torvalds #define labs(x) ({				\
841da177e4SLinus Torvalds 		long __x = (x);			\
851da177e4SLinus Torvalds 		(__x < 0) ? -__x : __x;		\
861da177e4SLinus Torvalds 	})
871da177e4SLinus Torvalds 
881da177e4SLinus Torvalds extern struct notifier_block *panic_notifier_list;
891da177e4SLinus Torvalds extern long (*panic_blink)(long time);
901da177e4SLinus Torvalds NORET_TYPE void panic(const char * fmt, ...)
911da177e4SLinus Torvalds 	__attribute__ ((NORET_AND format (printf, 1, 2)));
921da177e4SLinus Torvalds fastcall NORET_TYPE void do_exit(long error_code)
931da177e4SLinus Torvalds 	ATTRIB_NORET;
941da177e4SLinus Torvalds NORET_TYPE void complete_and_exit(struct completion *, long)
951da177e4SLinus Torvalds 	ATTRIB_NORET;
961da177e4SLinus Torvalds extern unsigned long simple_strtoul(const char *,char **,unsigned int);
971da177e4SLinus Torvalds extern long simple_strtol(const char *,char **,unsigned int);
981da177e4SLinus Torvalds extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
991da177e4SLinus Torvalds extern long long simple_strtoll(const char *,char **,unsigned int);
1001da177e4SLinus Torvalds extern int sprintf(char * buf, const char * fmt, ...)
1011da177e4SLinus Torvalds 	__attribute__ ((format (printf, 2, 3)));
1021da177e4SLinus Torvalds extern int vsprintf(char *buf, const char *, va_list)
1031da177e4SLinus Torvalds 	__attribute__ ((format (printf, 2, 0)));
1041da177e4SLinus Torvalds extern int snprintf(char * buf, size_t size, const char * fmt, ...)
1051da177e4SLinus Torvalds 	__attribute__ ((format (printf, 3, 4)));
1061da177e4SLinus Torvalds extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1071da177e4SLinus Torvalds 	__attribute__ ((format (printf, 3, 0)));
1081da177e4SLinus Torvalds extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
1091da177e4SLinus Torvalds 	__attribute__ ((format (printf, 3, 4)));
1101da177e4SLinus Torvalds extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1111da177e4SLinus Torvalds 	__attribute__ ((format (printf, 3, 0)));
1121da177e4SLinus Torvalds 
1131da177e4SLinus Torvalds extern int sscanf(const char *, const char *, ...)
1141da177e4SLinus Torvalds 	__attribute__ ((format (scanf, 2, 3)));
1151da177e4SLinus Torvalds extern int vsscanf(const char *, const char *, va_list)
1161da177e4SLinus Torvalds 	__attribute__ ((format (scanf, 2, 0)));
1171da177e4SLinus Torvalds 
1181da177e4SLinus Torvalds extern int get_option(char **str, int *pint);
1191da177e4SLinus Torvalds extern char *get_options(const char *str, int nints, int *ints);
1201da177e4SLinus Torvalds extern unsigned long long memparse(char *ptr, char **retptr);
1211da177e4SLinus Torvalds 
1221da177e4SLinus Torvalds extern int __kernel_text_address(unsigned long addr);
1231da177e4SLinus Torvalds extern int kernel_text_address(unsigned long addr);
1241da177e4SLinus Torvalds extern int session_of_pgrp(int pgrp);
1251da177e4SLinus Torvalds 
126d59745ceSMatt Mackall #ifdef CONFIG_PRINTK
1271da177e4SLinus Torvalds asmlinkage int vprintk(const char *fmt, va_list args)
1281da177e4SLinus Torvalds 	__attribute__ ((format (printf, 1, 0)));
1291da177e4SLinus Torvalds asmlinkage int printk(const char * fmt, ...)
1301da177e4SLinus Torvalds 	__attribute__ ((format (printf, 1, 2)));
131d59745ceSMatt Mackall #else
132d59745ceSMatt Mackall static inline int vprintk(const char *s, va_list args)
133d59745ceSMatt Mackall 	__attribute__ ((format (printf, 1, 0)));
134d59745ceSMatt Mackall static inline int vprintk(const char *s, va_list args) { return 0; }
135d59745ceSMatt Mackall static inline int printk(const char *s, ...)
136d59745ceSMatt Mackall 	__attribute__ ((format (printf, 1, 2)));
137d59745ceSMatt Mackall static inline int printk(const char *s, ...) { return 0; }
138d59745ceSMatt Mackall #endif
1391da177e4SLinus Torvalds 
1401da177e4SLinus Torvalds unsigned long int_sqrt(unsigned long);
1411da177e4SLinus Torvalds 
1421da177e4SLinus Torvalds static inline int __attribute_pure__ long_log2(unsigned long x)
1431da177e4SLinus Torvalds {
1441da177e4SLinus Torvalds 	int r = 0;
1451da177e4SLinus Torvalds 	for (x >>= 1; x > 0; x >>= 1)
1461da177e4SLinus Torvalds 		r++;
1471da177e4SLinus Torvalds 	return r;
1481da177e4SLinus Torvalds }
1491da177e4SLinus Torvalds 
1501da177e4SLinus Torvalds static inline unsigned long __attribute_const__ roundup_pow_of_two(unsigned long x)
1511da177e4SLinus Torvalds {
1521da177e4SLinus Torvalds 	return (1UL << fls(x - 1));
1531da177e4SLinus Torvalds }
1541da177e4SLinus Torvalds 
1551da177e4SLinus Torvalds extern int printk_ratelimit(void);
1561da177e4SLinus Torvalds extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
1571da177e4SLinus Torvalds 
1581da177e4SLinus Torvalds static inline void console_silent(void)
1591da177e4SLinus Torvalds {
1601da177e4SLinus Torvalds 	console_loglevel = 0;
1611da177e4SLinus Torvalds }
1621da177e4SLinus Torvalds 
1631da177e4SLinus Torvalds static inline void console_verbose(void)
1641da177e4SLinus Torvalds {
1651da177e4SLinus Torvalds 	if (console_loglevel)
1661da177e4SLinus Torvalds 		console_loglevel = 15;
1671da177e4SLinus Torvalds }
1681da177e4SLinus Torvalds 
1691da177e4SLinus Torvalds extern void bust_spinlocks(int yes);
1701da177e4SLinus Torvalds extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
171*dfed0449SAdrian Bunk extern __deprecated_for_modules int panic_timeout;
1721da177e4SLinus Torvalds extern int panic_on_oops;
1731da177e4SLinus Torvalds extern int tainted;
1741da177e4SLinus Torvalds extern const char *print_tainted(void);
1751da177e4SLinus Torvalds extern void add_taint(unsigned);
1761da177e4SLinus Torvalds 
1771da177e4SLinus Torvalds /* Values used for system_state */
1781da177e4SLinus Torvalds extern enum system_states {
1791da177e4SLinus Torvalds 	SYSTEM_BOOTING,
1801da177e4SLinus Torvalds 	SYSTEM_RUNNING,
1811da177e4SLinus Torvalds 	SYSTEM_HALT,
1821da177e4SLinus Torvalds 	SYSTEM_POWER_OFF,
1831da177e4SLinus Torvalds 	SYSTEM_RESTART,
1841da177e4SLinus Torvalds } system_state;
1851da177e4SLinus Torvalds 
1861da177e4SLinus Torvalds #define TAINT_PROPRIETARY_MODULE	(1<<0)
1871da177e4SLinus Torvalds #define TAINT_FORCED_MODULE		(1<<1)
1881da177e4SLinus Torvalds #define TAINT_UNSAFE_SMP		(1<<2)
1891da177e4SLinus Torvalds #define TAINT_FORCED_RMMOD		(1<<3)
1901da177e4SLinus Torvalds #define TAINT_MACHINE_CHECK		(1<<4)
1911da177e4SLinus Torvalds #define TAINT_BAD_PAGE			(1<<5)
1921da177e4SLinus Torvalds 
1931da177e4SLinus Torvalds extern void dump_stack(void);
1941da177e4SLinus Torvalds 
1951da177e4SLinus Torvalds #ifdef DEBUG
1961da177e4SLinus Torvalds #define pr_debug(fmt,arg...) \
1971da177e4SLinus Torvalds 	printk(KERN_DEBUG fmt,##arg)
1981da177e4SLinus Torvalds #else
1991da177e4SLinus Torvalds #define pr_debug(fmt,arg...) \
2001da177e4SLinus Torvalds 	do { } while (0)
2011da177e4SLinus Torvalds #endif
2021da177e4SLinus Torvalds 
2031da177e4SLinus Torvalds #define pr_info(fmt,arg...) \
2041da177e4SLinus Torvalds 	printk(KERN_INFO fmt,##arg)
2051da177e4SLinus Torvalds 
2061da177e4SLinus Torvalds /*
2071da177e4SLinus Torvalds  *      Display an IP address in readable format.
2081da177e4SLinus Torvalds  */
2091da177e4SLinus Torvalds 
2101da177e4SLinus Torvalds #define NIPQUAD(addr) \
2111da177e4SLinus Torvalds 	((unsigned char *)&addr)[0], \
2121da177e4SLinus Torvalds 	((unsigned char *)&addr)[1], \
2131da177e4SLinus Torvalds 	((unsigned char *)&addr)[2], \
2141da177e4SLinus Torvalds 	((unsigned char *)&addr)[3]
2151da177e4SLinus Torvalds 
2161da177e4SLinus Torvalds #define NIP6(addr) \
2171da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[0]), \
2181da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[1]), \
2191da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[2]), \
2201da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[3]), \
2211da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[4]), \
2221da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[5]), \
2231da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[6]), \
2241da177e4SLinus Torvalds 	ntohs((addr).s6_addr16[7])
2251da177e4SLinus Torvalds 
2261da177e4SLinus Torvalds #if defined(__LITTLE_ENDIAN)
2271da177e4SLinus Torvalds #define HIPQUAD(addr) \
2281da177e4SLinus Torvalds 	((unsigned char *)&addr)[3], \
2291da177e4SLinus Torvalds 	((unsigned char *)&addr)[2], \
2301da177e4SLinus Torvalds 	((unsigned char *)&addr)[1], \
2311da177e4SLinus Torvalds 	((unsigned char *)&addr)[0]
2321da177e4SLinus Torvalds #elif defined(__BIG_ENDIAN)
2331da177e4SLinus Torvalds #define HIPQUAD	NIPQUAD
2341da177e4SLinus Torvalds #else
2351da177e4SLinus Torvalds #error "Please fix asm/byteorder.h"
2361da177e4SLinus Torvalds #endif /* __LITTLE_ENDIAN */
2371da177e4SLinus Torvalds 
2381da177e4SLinus Torvalds /*
2391da177e4SLinus Torvalds  * min()/max() macros that also do
2401da177e4SLinus Torvalds  * strict type-checking.. See the
2411da177e4SLinus Torvalds  * "unnecessary" pointer comparison.
2421da177e4SLinus Torvalds  */
2431da177e4SLinus Torvalds #define min(x,y) ({ \
2441da177e4SLinus Torvalds 	typeof(x) _x = (x);	\
2451da177e4SLinus Torvalds 	typeof(y) _y = (y);	\
2461da177e4SLinus Torvalds 	(void) (&_x == &_y);		\
2471da177e4SLinus Torvalds 	_x < _y ? _x : _y; })
2481da177e4SLinus Torvalds 
2491da177e4SLinus Torvalds #define max(x,y) ({ \
2501da177e4SLinus Torvalds 	typeof(x) _x = (x);	\
2511da177e4SLinus Torvalds 	typeof(y) _y = (y);	\
2521da177e4SLinus Torvalds 	(void) (&_x == &_y);		\
2531da177e4SLinus Torvalds 	_x > _y ? _x : _y; })
2541da177e4SLinus Torvalds 
2551da177e4SLinus Torvalds /*
2561da177e4SLinus Torvalds  * ..and if you can't take the strict
2571da177e4SLinus Torvalds  * types, you can specify one yourself.
2581da177e4SLinus Torvalds  *
2591da177e4SLinus Torvalds  * Or not use min/max at all, of course.
2601da177e4SLinus Torvalds  */
2611da177e4SLinus Torvalds #define min_t(type,x,y) \
2621da177e4SLinus Torvalds 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
2631da177e4SLinus Torvalds #define max_t(type,x,y) \
2641da177e4SLinus Torvalds 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
2651da177e4SLinus Torvalds 
2661da177e4SLinus Torvalds 
2671da177e4SLinus Torvalds /**
2681da177e4SLinus Torvalds  * container_of - cast a member of a structure out to the containing structure
2691da177e4SLinus Torvalds  * @ptr:	the pointer to the member.
2701da177e4SLinus Torvalds  * @type:	the type of the container struct this is embedded in.
2711da177e4SLinus Torvalds  * @member:	the name of the member within the struct.
2721da177e4SLinus Torvalds  *
2731da177e4SLinus Torvalds  */
2741da177e4SLinus Torvalds #define container_of(ptr, type, member) ({			\
2751da177e4SLinus Torvalds         const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
2761da177e4SLinus Torvalds         (type *)( (char *)__mptr - offsetof(type,member) );})
2771da177e4SLinus Torvalds 
2781da177e4SLinus Torvalds /*
2791da177e4SLinus Torvalds  * Check at compile time that something is of a particular type.
2801da177e4SLinus Torvalds  * Always evaluates to 1 so you may use it easily in comparisons.
2811da177e4SLinus Torvalds  */
2821da177e4SLinus Torvalds #define typecheck(type,x) \
2831da177e4SLinus Torvalds ({	type __dummy; \
2841da177e4SLinus Torvalds 	typeof(x) __dummy2; \
2851da177e4SLinus Torvalds 	(void)(&__dummy == &__dummy2); \
2861da177e4SLinus Torvalds 	1; \
2871da177e4SLinus Torvalds })
2881da177e4SLinus Torvalds 
2891da177e4SLinus Torvalds #endif /* __KERNEL__ */
2901da177e4SLinus Torvalds 
2911da177e4SLinus Torvalds #define SI_LOAD_SHIFT	16
2921da177e4SLinus Torvalds struct sysinfo {
2931da177e4SLinus Torvalds 	long uptime;			/* Seconds since boot */
2941da177e4SLinus Torvalds 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
2951da177e4SLinus Torvalds 	unsigned long totalram;		/* Total usable main memory size */
2961da177e4SLinus Torvalds 	unsigned long freeram;		/* Available memory size */
2971da177e4SLinus Torvalds 	unsigned long sharedram;	/* Amount of shared memory */
2981da177e4SLinus Torvalds 	unsigned long bufferram;	/* Memory used by buffers */
2991da177e4SLinus Torvalds 	unsigned long totalswap;	/* Total swap space size */
3001da177e4SLinus Torvalds 	unsigned long freeswap;		/* swap space still available */
3011da177e4SLinus Torvalds 	unsigned short procs;		/* Number of current processes */
3021da177e4SLinus Torvalds 	unsigned short pad;		/* explicit padding for m68k */
3031da177e4SLinus Torvalds 	unsigned long totalhigh;	/* Total high memory size */
3041da177e4SLinus Torvalds 	unsigned long freehigh;		/* Available high memory size */
3051da177e4SLinus Torvalds 	unsigned int mem_unit;		/* Memory unit size in bytes */
3061da177e4SLinus Torvalds 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
3071da177e4SLinus Torvalds };
3081da177e4SLinus Torvalds 
309c0398ee6SNikita Danilov /* Force a compilation error if condition is true */
310921717a2SAndi Kleen #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
3111da177e4SLinus Torvalds 
3121da177e4SLinus Torvalds #ifdef CONFIG_SYSCTL
3131da177e4SLinus Torvalds extern int randomize_va_space;
3141da177e4SLinus Torvalds #else
3151da177e4SLinus Torvalds #define randomize_va_space 1
3161da177e4SLinus Torvalds #endif
3171da177e4SLinus Torvalds 
3181da177e4SLinus Torvalds /* Trap pasters of __FUNCTION__ at compile-time */
3191da177e4SLinus Torvalds #if __GNUC__ > 2 || __GNUC_MINOR__ >= 95
3201da177e4SLinus Torvalds #define __FUNCTION__ (__func__)
3211da177e4SLinus Torvalds #endif
3221da177e4SLinus Torvalds 
3231da177e4SLinus Torvalds #endif
324