xref: /linux-6.15/tools/include/uapi/linux/const.h (revision aaa6ef8a)
1*aaa6ef8aSArnaldo Carvalho de Melo /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2*aaa6ef8aSArnaldo Carvalho de Melo /* const.h: Macros for dealing with constants.  */
3*aaa6ef8aSArnaldo Carvalho de Melo 
4*aaa6ef8aSArnaldo Carvalho de Melo #ifndef _UAPI_LINUX_CONST_H
5*aaa6ef8aSArnaldo Carvalho de Melo #define _UAPI_LINUX_CONST_H
6*aaa6ef8aSArnaldo Carvalho de Melo 
7*aaa6ef8aSArnaldo Carvalho de Melo /* Some constant macros are used in both assembler and
8*aaa6ef8aSArnaldo Carvalho de Melo  * C code.  Therefore we cannot annotate them always with
9*aaa6ef8aSArnaldo Carvalho de Melo  * 'UL' and other type specifiers unilaterally.  We
10*aaa6ef8aSArnaldo Carvalho de Melo  * use the following macros to deal with this.
11*aaa6ef8aSArnaldo Carvalho de Melo  *
12*aaa6ef8aSArnaldo Carvalho de Melo  * Similarly, _AT() will cast an expression with a type in C, but
13*aaa6ef8aSArnaldo Carvalho de Melo  * leave it unchanged in asm.
14*aaa6ef8aSArnaldo Carvalho de Melo  */
15*aaa6ef8aSArnaldo Carvalho de Melo 
16*aaa6ef8aSArnaldo Carvalho de Melo #ifdef __ASSEMBLY__
17*aaa6ef8aSArnaldo Carvalho de Melo #define _AC(X,Y)	X
18*aaa6ef8aSArnaldo Carvalho de Melo #define _AT(T,X)	X
19*aaa6ef8aSArnaldo Carvalho de Melo #else
20*aaa6ef8aSArnaldo Carvalho de Melo #define __AC(X,Y)	(X##Y)
21*aaa6ef8aSArnaldo Carvalho de Melo #define _AC(X,Y)	__AC(X,Y)
22*aaa6ef8aSArnaldo Carvalho de Melo #define _AT(T,X)	((T)(X))
23*aaa6ef8aSArnaldo Carvalho de Melo #endif
24*aaa6ef8aSArnaldo Carvalho de Melo 
25*aaa6ef8aSArnaldo Carvalho de Melo #define _UL(x)		(_AC(x, UL))
26*aaa6ef8aSArnaldo Carvalho de Melo #define _ULL(x)		(_AC(x, ULL))
27*aaa6ef8aSArnaldo Carvalho de Melo 
28*aaa6ef8aSArnaldo Carvalho de Melo #define _BITUL(x)	(_UL(1) << (x))
29*aaa6ef8aSArnaldo Carvalho de Melo #define _BITULL(x)	(_ULL(1) << (x))
30*aaa6ef8aSArnaldo Carvalho de Melo 
31*aaa6ef8aSArnaldo Carvalho de Melo #endif /* _UAPI_LINUX_CONST_H */
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