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