1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/* const.h: Macros for dealing with constants. */
3
4#ifndef _LINUX_CONST_H
5#define _LINUX_CONST_H
6
7/* Some constant macros are used in both assembler and
8 * C code. Therefore we cannot annotate them always with
9 * 'UL' and other type specifiers unilaterally. We
10 * use the following macros to deal with this.
11 *
12 * Similarly, _AT() will cast an expression with a type in C, but
13 * leave it unchanged in asm.
14 */
15
16#ifdef __ASSEMBLY__
17#define _AC(X,Y) X
18#define _AT(T,X) X
19#else
20#define __AC(X,Y) (X##Y)
21#define _AC(X,Y) __AC(X,Y)
22#define _AT(T,X) ((T)(X))
23#endif
24
25#define _UL(x) (_AC(x, UL))
26#define _ULL(x) (_AC(x, ULL))
27
28#define _BITUL(x) (_UL(1) << (x))
29#define _BITULL(x) (_ULL(1) << (x))
30
31#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
32#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
33
34#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
35
36#endif /* _LINUX_CONST_H */
37

source code of include/linux/const.h