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| -rw-r--r-- | include/linux/const.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/const.h b/include/linux/const.h new file mode 100644 index 0000000000..379c889232 --- /dev/null +++ b/include/linux/const.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _LINUX_CONST_H +#define _LINUX_CONST_H + +/* const.h: Macros for dealing with constants. */ + +/* Some constant macros are used in both assembler and + * C code. Therefore we cannot annotate them always with + * 'UL' and other type specifiers unilaterally. We + * use the following macros to deal with this. + * + * Similarly, _AT() will cast an expression with a type in C, but + * leave it unchanged in asm. + */ + +#ifdef __ASSEMBLY__ +#define _AC(X,Y) X +#define _AT(T,X) X +#else +#define __AC(X,Y) (X##Y) +#define _AC(X,Y) __AC(X,Y) +#define _AT(T,X) ((T)(X)) +#endif + +#define _UL(x) (_AC(x, UL)) +#define _ULL(x) (_AC(x, ULL)) + +#define _BITUL(x) (_UL(1) << (x)) +#define _BITULL(x) (_ULL(1) << (x)) + +#define UL(x) (_UL(x)) +#define ULL(x) (_ULL(x)) + +#endif /* _LINUX_CONST_H */ |