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 <linux/bitops.h>
#include <linux/log2.h>
#include <asm/byteorder.h>
#include <asm/bug.h>

extern const char linux_banner[];
extern const char linux_proc_banner[];

#define USHORT_MAX	((u16)(~0U))
#define SHORT_MAX	((s16)(USHORT_MAX>>1))
#define SHORT_MIN	(-SHORT_MAX - 1)
#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 LLONG_MAX	((long long)(~0ULL>>1))
#define LLONG_MIN	(-LLONG_MAX - 1)
#define ULLONG_MAX	(~0ULL)

#define STACK_MAGIC	0xdeadbeef

#define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
#define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
#define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)

#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))

#ifdef CONFIG_LBD
# include <asm/div64.h>
# define sector_div(a, b) do_div(a, b)
#else
# define sector_div(n, b)( \
{ \
	int _res; \
	_res = (n) % (b); \
	(n) /= (b); \
	_res; \
} \
)
#endif

/**
 * upper_32_bits - return bits 32-63 of a number
 * @n: the number we're accessing
 *
 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
 * the "right shift count >= width of type" warning when that quantity is
 * 32-bits.
 */
#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))

#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			*/

/*
 * Annotation for a "continued" line of log printout (only done after a
 * line that had no enclosing \n). Only to be used by core/arch code
 * during early bootup (a continued line is not SMP-safe otherwise).
 */
#define	KERN_CONT	""

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])

struct completion;
struct pt_regs;
struct user;

/**
 * might_sleep - annotation for functions that can sleep
 *
 * this macro will print a stack trace if it is executed in an atomic
 * context (spinlock, irq-handler, ...).
 *
 * This is a useful debugging help to be able to catch problems early and not
 * be bitten later when the calling function happens to sleep when it is not
 * supposed to.
 */
#ifdef CONFIG_PREEMPT_VOLUNTARY
extern int _cond_resched(void);
# define might_resched() _cond_resched()
#else
# define might_resched() do { } while (0)
#endif

#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
  void __might_sleep(char *file, int line);
# define might_sleep() \
	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
#else
# define might_sleep() do { might_resched(); } while (0)
#endif

#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)

#define abs(x) ({				\
		int __x = (x);			\
		(__x < 0) ? -__x : __x;		\
	})

extern struct atomic_notifier_head panic_notifier_list;
extern long (*panic_blink)(long time);
NORET_TYPE void panic(const char * fmt, ...)
	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
extern void oops_enter(void);
extern void oops_exit(void);
extern int oops_may_print(void);
NORET_TYPE void do_exit(long error_code)
	ATTRIB_NORET;
NORET_TYPE void complete_and_exit(struct completion *, long)
	ATTRIB_NORET;
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 strict_strtoul(const char *, unsigned int, unsigned long *);
extern int strict_strtol(const char *, unsigned int, long *);
extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
extern int strict_strtoll(const char *, unsigned int, long long *);
extern int sprintf(char * buf, const char * fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
extern int vsprintf(char *buf, const char *, va_list)
	__attribute__ ((format (printf, 2, 0)));
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)
	__attribute__ ((format (printf, 3, 0)));
extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
	__attribute__ ((format (printf, 3, 4)));
extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
	__attribute__ ((format (printf, 3, 0)));
extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
	__attribute__ ((format (printf, 2, 3)));
extern char *kvasprintf(gfp_t gfp, 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)
	__attribute__ ((format (scanf, 2, 0)));

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

extern int core_kernel_text(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);

#ifdef CONFIG_PRINTK
asmlinkage int vprintk(const char *fmt, va_list args)
	__attribute__ ((format (printf, 1, 0)));
asmlinkage int printk(const char * fmt, ...)
	__attribute__ ((format (printf, 1, 2))) __cold;
extern int log_buf_get_len(void);
extern int log_buf_read(int idx);
extern int log_buf_copy(char *dest, int idx, int len);

extern int printk_ratelimit_jiffies;
extern int printk_ratelimit_burst;
extern int printk_ratelimit(void);
extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
				   unsigned int interval_msec);
#else
static inline int vprintk(const char *s, va_list args)
	__attribute__ ((format (printf, 1, 0)));
static inline int vprintk(const char *s, va_list args) { return 0; }
static inline int printk(const char *s, ...)
	__attribute__ ((format (printf, 1, 2)));
static inline int __cold printk(const char *s, ...) { return 0; }
static inline int log_buf_get_len(void) { return 0; }
static inline int log_buf_read(int idx) { return 0; }
static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
static inline int printk_ratelimit(void) { return 0; }
static inline int __printk_ratelimit(int ratelimit_jiffies, \
				     int ratelimit_burst) { return 0; }
static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
					  unsigned int interval_msec)	\
		{ return false; }
#endif

extern void __attribute__((format(printf, 1, 2)))
	early_printk(const char *fmt, ...);

unsigned long int_sqrt(unsigned long);

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 void wake_up_klogd(void);
extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
extern int panic_timeout;
extern int panic_on_oops;
extern int panic_on_unrecovered_nmi;
extern int tainted;
extern const char *print_tainted(void);
extern void add_taint(unsigned);
extern int root_mountflags;

/* Values used for system_state */
extern enum system_states {
	SYSTEM_BOOTING,
	SYSTEM_RUNNING,
	SYSTEM_HALT,
	SYSTEM_POWER_OFF,
	SYSTEM_RESTART,
	SYSTEM_SUSPEND_DISK,
} system_state;

#define TAINT_PROPRIETARY_MODULE	(1<<0)
#define TAINT_FORCED_MODULE		(1<<1)
#define TAINT_UNSAFE_SMP		(1<<2)
#define TAINT_FORCED_RMMOD		(1<<3)
#define TAINT_MACHINE_CHECK		(1<<4)
#define TAINT_BAD_PAGE			(1<<5)
#define TAINT_USER			(1<<6)
#define TAINT_DIE			(1<<7)
#define TAINT_OVERRIDDEN_ACPI_TABLE	(1<<8)
#define TAINT_WARN			(1<<9)

extern void dump_stack(void) __cold;

enum {
	DUMP_PREFIX_NONE,
	DUMP_PREFIX_ADDRESS,
	DUMP_PREFIX_OFFSET
};
extern void hex_dump_to_buffer(const void *buf, size_t len,
				int rowsize, int groupsize,
				char *linebuf, size_t linebuflen, bool ascii);
extern void print_hex_dump(const char *level, const char *prefix_str,
				int prefix_type, int rowsize, int groupsize,
				const void *buf, size_t len, bool ascii);
extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
			const void *buf, size_t len);
#define hex_asc(x)	"0123456789abcdef"[x]

#define pr_emerg(fmt, arg...) \
	printk(KERN_EMERG fmt, ##arg)
#define pr_alert(fmt, arg...) \
	printk(KERN_ALERT fmt, ##arg)
#define pr_crit(fmt, arg...) \
	printk(KERN_CRIT fmt, ##arg)
#define pr_err(fmt, arg...) \
	printk(KERN_ERR fmt, ##arg)
#define pr_warning(fmt, arg...) \
	printk(KERN_WARNING fmt, ##arg)
#define pr_notice(fmt, arg...) \
	printk(KERN_NOTICE fmt, ##arg)
#define pr_info(fmt, arg...) \
	printk(KERN_INFO fmt, ##arg)

#ifdef DEBUG
/* If you are writing a driver, please use dev_dbg instead */
#define pr_debug(fmt, arg...) \
	printk(KERN_DEBUG fmt, ##arg)
#else
#define pr_debug(fmt, arg...) \
	({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
#endif

/*
 *      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]
#define NIPQUAD_FMT "%u.%u.%u.%u"

#define NIP6(addr) \
	ntohs((addr).s6_addr16[0]), \
	ntohs((addr).s6_addr16[1]), \
	ntohs((addr).s6_addr16[2]), \
	ntohs((addr).s6_addr16[3]), \
	ntohs((addr).s6_addr16[4]), \
	ntohs((addr).s6_addr16[5]), \
	ntohs((addr).s6_addr16[6]), \
	ntohs((addr).s6_addr16[7])
#define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
#define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"

#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()/clamp() macros that also do
 * strict type-checking.. See the
 * "unnecessary" pointer comparison.
 */
#define min(x, y) ({				\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })

#define max(x, y) ({				\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })

/**
 * clamp - return a value clamped to a given range with strict typechecking
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does strict typechecking of min/max to make sure they are of the
 * same type as val.  See the unnecessary pointer comparisons.
 */
#define clamp(val, min, max) ({			\
	typeof(val) __val = (val);		\
	typeof(min) __min = (min);		\
	typeof(max) __max = (max);		\
	(void) (&__val == &__min);		\
	(void) (&__val == &__max);		\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })

/*
 * ..and if you can't take the strict
 * types, you can specify one yourself.
 *
 * Or not use min/max/clamp at all, of course.
 */
#define min_t(type, x, y) ({			\
	type __min1 = (x);			\
	type __min2 = (y);			\
	__min1 < __min2 ? __min1: __min2; })

#define max_t(type, x, y) ({			\
	type __max1 = (x);			\
	type __max2 = (y);			\
	__max1 > __max2 ? __max1: __max2; })

/**
 * clamp_t - return a value clamped to a given range using a given type
 * @type: the type of variable to use
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of type
 * 'type' to make all the comparisons.
 */
#define clamp_t(type, val, min, max) ({		\
	type __val = (val);			\
	type __min = (min);			\
	type __max = (max);			\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })

/**
 * clamp_val - return a value clamped to a given range using val's type
 * @val: current value
 * @min: minimum allowable value
 * @max: maximum allowable value
 *
 * This macro does no typechecking and uses temporary variables of whatever
 * type the input argument 'val' is.  This is useful when val is an unsigned
 * type and min and max are literals that will otherwise be assigned a signed
 * integer type.
 */
#define clamp_val(val, min, max) ({		\
	typeof(val) __val = (val);		\
	typeof(val) __min = (min);		\
	typeof(val) __max = (max);		\
	__val = __val < __min ? __min: __val;	\
	__val > __max ? __max: __val; })

/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:	the pointer to the member.
 * @type:	the type of the container struct this is embedded in.
 * @member:	the name of the member within the struct.
 *
 */
#define container_of(ptr, type, member) ({			\
	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
	(type *)( (char *)__mptr - offsetof(type,member) );})

/*
 * Check at compile time that something is of a particular type.
 * Always evaluates to 1 so you may use it easily in comparisons.
 */
#define typecheck(type,x) \
({	type __dummy; \
	typeof(x) __dummy2; \
	(void)(&__dummy == &__dummy2); \
	1; \
})

/*
 * Check at compile time that 'function' is a certain type, or is a pointer
 * to that type (needs to use typedef for the function type.)
 */
#define typecheck_fn(type,function) \
({	typeof(type) __tmp = function; \
	(void)__tmp; \
})

struct sysinfo;
extern int do_sysinfo(struct sysinfo *info);

#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.. */
};

/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))

/* Force a compilation error if condition is true, but also produce a
   result (of value 0 and type size_t), so the expression can be used
   e.g. in a structure initializer (or where-ever else comma expressions
   aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)

/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)

/* This helps us to avoid #ifdef CONFIG_NUMA */
#ifdef CONFIG_NUMA
#define NUMA_BUILD 1
#else
#define NUMA_BUILD 0
#endif

#endif