include/linux/kernel.h

#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H

/*
 * 'kernel.h' contains some often-used function prototypes etc
 */

#ifdef __KERNEL__

#include <stdarg.h>
#include <linux/linkage.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/byteorder.h>

/* Optimization barrier */
/* The "volatile" is due to gcc bugs */
#define barrier() __asm__ __volatile__("": : :"memory")

#define INT_MAX		((int)(~0U>>1))
#define INT_MIN		(-INT_MAX - 1)
#define UINT_MAX	(~0U)
#define LONG_MAX	((long)(~0UL>>1))
#define LONG_MIN	(-LONG_MAX - 1)
#define ULONG_MAX	(~0UL)

#define STACK_MAGIC	0xdeadbeef

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

#define	KERN_EMERG	"<0>"	/* system is unusable			*/
#define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
#define	KERN_CRIT	"<2>"	/* critical conditions			*/
#define	KERN_ERR	"<3>"	/* error conditions			*/
#define	KERN_WARNING	"<4>"	/* warning conditions			*/
#define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
#define	KERN_INFO	"<6>"	/* informational			*/
#define	KERN_DEBUG	"<7>"	/* debug-level messages			*/

extern int console_printk[];

#define console_loglevel (console_printk[0])
#define default_message_loglevel (console_printk[1])
#define minimum_console_loglevel (console_printk[2])
#define default_console_loglevel (console_printk[3])

# define NORET_TYPE    /**/
# define ATTRIB_NORET  __attribute__((noreturn))
# define NORET_AND     noreturn,

#if defined(__i386__) || defined(UM_FASTCALL)
#define FASTCALL(x)	x __attribute__((regparm(3)))
#else
#define FASTCALL(x)	x
#endif

struct completion;

extern struct notifier_block *panic_notifier_list;
NORET_TYPE void panic(const char * fmt, ...)
	__attribute__ ((NORET_AND format (printf, 1, 2)));
asmlinkage NORET_TYPE void do_exit(long error_code)
	ATTRIB_NORET;
NORET_TYPE void complete_and_exit(struct completion *, long)
	ATTRIB_NORET;
extern int abs(int);
extern unsigned long simple_strtoul(const char *,char **,unsigned int);
extern long simple_strtol(const char *,char **,unsigned int);
extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
extern long long simple_strtoll(const char *,char **,unsigned int);
extern int sprintf(char * buf, const char * fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
extern int vsprintf(char *buf, const char *, va_list);
extern int snprintf(char * buf, size_t size, const char * fmt, ...)
	__attribute__ ((format (printf, 3, 4)));
extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);

extern int sscanf(const char *, const char *, ...)
	__attribute__ ((format (scanf,2,3)));
extern int vsscanf(const char *, const char *, va_list);

extern int get_option(char **str, int *pint);
extern char *get_options(char *str, int nints, int *ints);
extern unsigned long long memparse(char *ptr, char **retptr);
extern void dev_probe_lock(void);
extern void dev_probe_unlock(void);

extern int session_of_pgrp(int pgrp);

asmlinkage int printk(const char * fmt, ...)
	__attribute__ ((format (printf, 1, 2)));

static inline void console_silent(void)
{
	console_loglevel = 0;
}

static inline void console_verbose(void)
{
	if (console_loglevel)
		console_loglevel = 15;
}

extern void bust_spinlocks(int yes);
extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */

extern int tainted;
extern const char *print_tainted(void);

extern void dump_stack(void);

#if DEBUG
#define pr_debug(fmt,arg...) \
	printk(KERN_DEBUG fmt,##arg)
#else
#define pr_debug(fmt,arg...) \
	do { } while (0)
#endif

#define pr_info(fmt,arg...) \
	printk(KERN_INFO fmt,##arg)

/*
 *      Display an IP address in readable format.
 */

#define NIPQUAD(addr) \
	((unsigned char *)&addr)[0], \
	((unsigned char *)&addr)[1], \
	((unsigned char *)&addr)[2], \
	((unsigned char *)&addr)[3]

#if defined(__LITTLE_ENDIAN)
#define HIPQUAD(addr) \
	((unsigned char *)&addr)[3], \
	((unsigned char *)&addr)[2], \
	((unsigned char *)&addr)[1], \
	((unsigned char *)&addr)[0]
#elif defined(__BIG_ENDIAN)
#define HIPQUAD	NIPQUAD
#else
#error "Please fix asm/byteorder.h"
#endif /* __LITTLE_ENDIAN */

/*
 * min()/max() macros that also do
 * strict type-checking.. See the
 * "unnecessary" pointer comparison.
 */
#define min(x,y) ({ \
	const typeof(x) _x = (x);	\
	const typeof(y) _y = (y);	\
	(void) (&_x == &_y);		\
	_x < _y ? _x : _y; })

#define max(x,y) ({ \
	const typeof(x) _x = (x);	\
	const typeof(y) _y = (y);	\
	(void) (&_x == &_y);		\
	_x > _y ? _x : _y; })

/*
 * ..and if you can't take the strict
 * types, you can specify one yourself.
 *
 * Or not use min/max at all, of course.
 */
#define min_t(type,x,y) \
	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
#define max_t(type,x,y) \
	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })

extern void __out_of_line_bug(int line) ATTRIB_NORET;
#define out_of_line_bug() __out_of_line_bug(__LINE__)

#endif /* __KERNEL__ */

#define SI_LOAD_SHIFT	16
struct sysinfo {
	long uptime;			/* Seconds since boot */
	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
	unsigned long totalram;		/* Total usable main memory size */
	unsigned long freeram;		/* Available memory size */
	unsigned long sharedram;	/* Amount of shared memory */
	unsigned long bufferram;	/* Memory used by buffers */
	unsigned long totalswap;	/* Total swap space size */
	unsigned long freeswap;		/* swap space still available */
	unsigned short procs;		/* Number of current processes */
	unsigned short pad;		/* explicit padding for m68k */
	unsigned long totalhigh;	/* Total high memory size */
	unsigned long freehigh;		/* Available high memory size */
	unsigned int mem_unit;		/* Memory unit size in bytes */
	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
};

#define BUG_ON(condition) do { if (unlikely((condition)!=0)) BUG(); } while(0)

#endif /* _LINUX_KERNEL_H */