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