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#if !defined(__ASSEMBLY__)
32/*
33 * Missing __asm__ support
34 *
35 * __BIT128() would not work in the __asm__ code, as it shifts an
36 * 'unsigned __int128' data type as direct representation of
37 * 128 bit constants is not supported in the gcc compiler, as
38 * they get silently truncated.
39 *
40 * TODO: Please revisit this implementation when gcc compiler
41 * starts representing 128 bit constants directly like long
42 * and unsigned long etc. Subsequently drop the comment for
43 * GENMASK_U128() which would then start supporting __asm__ code.
44 */
45#define _BIT128(x)	((unsigned __int128)(1) << (x))
46#endif
47
48#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
49#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
50
51#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
52
53#endif /* _LINUX_CONST_H */