matos/core/kernel.h

#pragma once

#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d)-1) / (d))
#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a)-1)
#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))

/* @a is a power of 2 value */
#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a)-1), (a))
#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_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)


#ifdef __CHECKER__
#define BUILD_BUG_ON_ZERO(e) (0)
#else /* __CHECKER__ */
/*
 * Force a compilation error if condition is true, but also produce a
 * result (of value 0 and type int), 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) ((int)(sizeof(struct { int:(-!!(e)); })))
#endif /* __CHECKER__ */
/* Are two types/vars the same type (ignoring qualifiers)? */
#ifndef __same_type
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#endif
/* &a[0] degrades to a pointer: a different type from an array */
#define __must_be_array(a)	BUILD_BUG_ON_ZERO(__same_type((a), &(a)[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.
 */
#define __round_mask(x, y) ((__typeof__(x))((y)-1))
/**
 * round_up - round up to next specified power of 2
 * @x: the value to round
 * @y: multiple to round up to (must be a power of 2)
 *
 * Rounds @x up to next multiple of @y (which must be a power of 2).
 * To perform arbitrary rounding up, use roundup() below.
 */
#define round_up(x, y) ((((x)-1) | __round_mask(x, y)) + 1)
/**
 * round_down - round down to next specified power of 2
 * @x: the value to round
 * @y: multiple to round down to (must be a power of 2)
 *
 * Rounds @x down to next multiple of @y (which must be a power of 2).
 * To perform arbitrary rounding down, use rounddown() below.
 */
#define round_down(x, y) ((x) & ~__round_mask(x, y))

#define typeof_member(T, m) typeof(((T *)0)->m)

#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
/**
 * roundup - round up to the next specified multiple
 * @x: the value to up
 * @y: multiple to round up to
 *
 * Rounds @x up to next multiple of @y. If @y will always be a power
 * of 2, consider using the faster round_up().
 */
#define roundup(x, y)                                                                         \
    ({                                                                                        \
        typeof(y) __y = y;                                                                    \
        (((x) + (__y - 1)) / __y) * __y;                                                      \
    })
/**
 * rounddown - round down to next specified multiple
 * @x: the value to round
 * @y: multiple to round down to
 *
 * Rounds @x down to next multiple of @y. If @y will always be a power
 * of 2, consider using the faster round_down().
 */
#define rounddown(x, y)                                                                       \
    ({                                                                                        \
        typeof(x) __x = (x);                                                                  \
        __x - (__x % (y));                                                                    \
    })

#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MAX(a, b) (((a) > (b)) ? (a) : (b))