path: root/include/linux/kernel.h

#ifndef _LINUX_KERNEL_H
#define _LINUX_KERNEL_H

#include <linux/compiler.h>
#include <linux/bug.h>
#include <linux/barebox-wrapper.h>

#define USHRT_MAX	((u16)(~0U))
#define SHRT_MAX	((s16)(USHRT_MAX>>1))
#define SHRT_MIN	((s16)(-SHRT_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 SIZE_MAX	(~(size_t)0)

#define U8_MAX		((u8)~0U)
#define S8_MAX		((s8)(U8_MAX>>1))
#define S8_MIN		((s8)(-S8_MAX - 1))
#define U16_MAX		((u16)~0U)
#define S16_MAX		((s16)(U16_MAX>>1))
#define S16_MIN		((s16)(-S16_MAX - 1))
#define U32_MAX		((u32)~0U)
#define S32_MAX		((s32)(U32_MAX>>1))
#define S32_MIN		((s32)(-S32_MAX - 1))
#define U64_MAX		((u64)~0ULL)
#define S64_MAX		((s64)(U64_MAX>>1))
#define S64_MIN		((s64)(-S64_MAX - 1))

#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))

/*
 * This looks more complex than it should be. But we need to
 * get the type for the ~ right in round_down (it needs to be
 * as wide as the result!), and we want to evaluate the macro
 * arguments just once each.
 *
 * NOTE these functions only round to power-of-2 arguments. Use
 * roundup/rounddown for non power-of-2-arguments.
 */
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))

#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

#define DIV_ROUND_CLOSEST(x, divisor)(			\
{							\
	typeof(divisor) __divisor = divisor;		\
	(((x) + ((__divisor) / 2)) / (__divisor));	\
}							\
)

/**
 * 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))

/**
 * lower_32_bits - return bits 0-31 of a number
 * @n: the number we're accessing
 */
#define lower_32_bits(n) ((u32)(n))

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

#define abs64(x) ({                             \
		s64 __x = (x);                  \
		(__x < 0) ? -__x : __x;         \
	})

void __noreturn panic(const char *fmt, ...);

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);

/*
 * 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; })

#define min3(x, y, z) ({			\
	typeof(x) _min1 = (x);			\
	typeof(y) _min2 = (y);			\
	typeof(z) _min3 = (z);			\
	(void) (&_min1 == &_min2);		\
	(void) (&_min1 == &_min3);		\
	_min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) :	\
		(_min2 < _min3 ? _min2 : _min3); })

#define max3(x, y, z) ({			\
	typeof(x) _max1 = (x);			\
	typeof(y) _max2 = (y);			\
	typeof(z) _max3 = (z);			\
	(void) (&_max1 == &_max2);		\
	(void) (&_max1 == &_max3);		\
	_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) :	\
		(_max2 > _max3 ? _max2 : _max3); })

/**
 * 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; })


/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
#define roundup(x, y) (					\
{							\
	const typeof(y) __y = y;			\
	(((x) + (__y - 1)) / __y) * __y;		\
}							\
)
#define rounddown(x, y) (				\
{							\
	typeof(x) __x = (x);				\
	__x - (__x % (y));				\
}							\
)

/*
 * Multiplies an integer by a fraction, while avoiding unnecessary
 * overflow or loss of precision.
 */
#define mult_frac(x, numer, denom)(			\
{							\
	typeof(x) quot = (x) / (denom);			\
	typeof(x) rem  = (x) % (denom);			\
	(quot * (numer)) + ((rem * (numer)) / (denom));	\
}							\
)

extern const char hex_asc[];
#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]

static inline char *hex_byte_pack(char *buf, u8 byte)
{
	*buf++ = hex_asc_hi(byte);
	*buf++ = hex_asc_lo(byte);
	return buf;
}

extern const char hex_asc_upper[];
#define hex_asc_upper_lo(x)	hex_asc_upper[((x) & 0x0f)]
#define hex_asc_upper_hi(x)	hex_asc_upper[((x) & 0xf0) >> 4]

static inline char *hex_byte_pack_upper(char *buf, u8 byte)
{
	*buf++ = hex_asc_upper_hi(byte);
	*buf++ = hex_asc_upper_lo(byte);
	return buf;
}

extern int hex_to_bin(char ch);
extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
extern char *bin2hex(char *dst, const void *src, size_t count);

/**
 * 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) );})

/*
 * swap - swap value of @a and @b
 */
#define swap(a, b) \
	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)

#endif /* _LINUX_KERNEL_H */