Viewing: lstddef.h
#ifndef _LSTDDEF_H
#define _LSTDDEF_H
#include <unistd.h>
#include <linux/types.h>
#include <sys/param.h>
#include <sys/syscall.h>
#include <sys/types.h>
#define __ALIGN_LSTDDEF_MASK(x, mask) (((x) + (mask)) & ~(mask))
#define __ALIGN_LSTDDEF(x, a) __ALIGN_LSTDDEF_MASK(x, (typeof(x))(a) - 1)
#define __LSTDDEF_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
#define ALIGN(x, a) __ALIGN_LSTDDEF((x), (a))
#define ALIGN_DOWN(x, a) __ALIGN_LSTDDEF((x) - ((a) - 1), (a))
#define __ALIGN_MASK(x, mask) __ALIGN_LSTDDEF_MASK((x), (mask))
#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
#ifndef __must_be_array
# define __must_be_array(arr) 0
#endif
#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.
*/
#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 __USER_DIV_ROUND_UP
#define DIV_ROUND_DOWN_ULL(ll, d) \
({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
#define DIV_ROUND_UP_ULL(ll, d) DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))
#if BITS_PER_LONG == 32
# define DIV_ROUND_UP_SECTOR_T(ll, d) DIV_ROUND_UP_ULL(ll, d)
#else
# define DIV_ROUND_UP_SECTOR_T(ll, d) DIV_ROUND_UP(ll, d)
#endif
#define rounddown(x, y) ({ \
typeof(x) __x = (x); \
__x - (__x % (y)); \
})
/*
* Divide positive or negative dividend by positive divisor and round
* to closest integer. Result is undefined for negative divisors and
* for negative dividends if the divisor variable type is unsigned.
*/
#define DIV_ROUND_CLOSEST(x, divisor) ({ \
typeof(x) __x = x; \
typeof(divisor) __d = divisor; \
(((typeof(x))-1) > 0 || \
((typeof(divisor))-1) > 0 || (__x) > 0) ? \
(((__x) + ((__d) / 2)) / (__d)) : \
(((__x) - ((__d) / 2)) / (__d)); \
})
/*
* Same as above but for u64 dividends. divisor must be a 32-bit
* number.
*/
#define DIV_ROUND_CLOSEST_ULL(x, divisor) ({ \
typeof(divisor) __d = divisor; \
unsigned long long _tmp = (x) + (__d) / 2; \
do_div(_tmp, __d); \
_tmp; \
})
/*
* 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)); \
})
/**
* 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))
/**
* abs - return absolute value of an argument
* @x: the value. If it is unsigned type, it is converted to signed type first
* (s64, long or int depending on its size).
*
* Return: an absolute value of x. If x is 64-bit, macro's return type is s64,
* otherwise it is signed long.
*/
#define abs(x) __builtin_choose_expr(sizeof(x) == sizeof(__s64), ({ \
__s64 __x = (x); \
(__x < 0) ? -__x : __x; \
}), ({ \
long ret; \
if (sizeof(x) == sizeof(long)) { \
long __x = (x); \
ret = (__x < 0) ? -__x : __x; \
} else { \
int __x = (x); \
ret = (__x < 0) ? -__x : __x; \
} \
ret; \
}))
/**
* reciprocal_scale - "scale" a value into range [0, ep_ro)
* @val: value
* @ep_ro: right open interval endpoint
*
* Perform a "reciprocal multiplication" in order to "scale" a value into
* range [0, ep_ro), where the upper interval endpoint is right-open.
* This is useful, e.g. for accessing a index of an array containing
* ep_ro elements, for example. Think of it as sort of modulus, only that
* the result isn't that of modulo. ;) Note that if initial input is a
* small value, then result will return 0.
*
* Return: a result based on val in interval [0, ep_ro).
*/
static inline __u32 reciprocal_scale(__u32 val, __u32 ep_ro)
{
return (__u32)(((__u64) val * ep_ro) >> 32);
}
/*
* 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); \
})
/**
* min_not_zero - return the minimum that is _not_ zero, unless both are zero
* @x: value1
* @y: value2
*/
#define min_not_zero(x, y) ({ \
typeof(x) __x = (x); \
typeof(y) __y = (y); \
__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); \
})
/**
* 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; \
})
/*
* swap - swap value of @a and @b
*/
#define swap(a, b) do { \
typeof(a) __tmp = (a); \
(a) = (b); \
(b) = __tmp; \
} while (0)
/**
* 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)); \
})
#ifndef HAVE_COPY_FILE_RANGE
#ifndef __NR_copy_file_range
#if defined(_ASM_X86_UNISTD_64_H)
#define __NR_copy_file_range 326
#elif defined(_ASM_X86_UNISTD_32_H)
#define __NR_copy_file_range 285
#else
#define __NR_copy_file_range 285
#endif
#endif
static inline loff_t copy_file_range(int fd_in, loff_t *off_in, int fd_out,
loff_t *off_out, size_t len,
unsigned int flags)
{
return syscall(__NR_copy_file_range, fd_in, off_in, fd_out,
off_out, len, flags);
}
#endif /* !HAVE_COPY_FILE_RANGE */
#endif /* !_LSTDDEF_H */
