1b3c818a4SEric Farman /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2b3c818a4SEric Farman /* const.h: Macros for dealing with constants. */ 3b3c818a4SEric Farman 4b3c818a4SEric Farman #ifndef _LINUX_CONST_H 5b3c818a4SEric Farman #define _LINUX_CONST_H 6b3c818a4SEric Farman 7b3c818a4SEric Farman /* Some constant macros are used in both assembler and 8b3c818a4SEric Farman * C code. Therefore we cannot annotate them always with 9b3c818a4SEric Farman * 'UL' and other type specifiers unilaterally. We 10b3c818a4SEric Farman * use the following macros to deal with this. 11b3c818a4SEric Farman * 12b3c818a4SEric Farman * Similarly, _AT() will cast an expression with a type in C, but 13b3c818a4SEric Farman * leave it unchanged in asm. 14b3c818a4SEric Farman */ 15b3c818a4SEric Farman 16b3c818a4SEric Farman #ifdef __ASSEMBLY__ 17b3c818a4SEric Farman #define _AC(X,Y) X 18b3c818a4SEric Farman #define _AT(T,X) X 19b3c818a4SEric Farman #else 20b3c818a4SEric Farman #define __AC(X,Y) (X##Y) 21b3c818a4SEric Farman #define _AC(X,Y) __AC(X,Y) 22b3c818a4SEric Farman #define _AT(T,X) ((T)(X)) 23b3c818a4SEric Farman #endif 24b3c818a4SEric Farman 25b3c818a4SEric Farman #define _UL(x) (_AC(x, UL)) 26b3c818a4SEric Farman #define _ULL(x) (_AC(x, ULL)) 27b3c818a4SEric Farman 28b3c818a4SEric Farman #define _BITUL(x) (_UL(1) << (x)) 29b3c818a4SEric Farman #define _BITULL(x) (_ULL(1) << (x)) 30b3c818a4SEric Farman 310d2eeef7SBibo Mao #if !defined(__ASSEMBLY__) 320d2eeef7SBibo Mao /* 330d2eeef7SBibo Mao * Missing __asm__ support 340d2eeef7SBibo Mao * 350d2eeef7SBibo Mao * __BIT128() would not work in the __asm__ code, as it shifts an 36*1cab5a02SRorie Reyes * 'unsigned __int128' data type as direct representation of 370d2eeef7SBibo Mao * 128 bit constants is not supported in the gcc compiler, as 380d2eeef7SBibo Mao * they get silently truncated. 390d2eeef7SBibo Mao * 400d2eeef7SBibo Mao * TODO: Please revisit this implementation when gcc compiler 410d2eeef7SBibo Mao * starts representing 128 bit constants directly like long 420d2eeef7SBibo Mao * and unsigned long etc. Subsequently drop the comment for 430d2eeef7SBibo Mao * GENMASK_U128() which would then start supporting __asm__ code. 440d2eeef7SBibo Mao */ 450d2eeef7SBibo Mao #define _BIT128(x) ((unsigned __int128)(1) << (x)) 460d2eeef7SBibo Mao #endif 470d2eeef7SBibo Mao 48d0bf492fSCédric Le Goater #define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1) 49b3c818a4SEric Farman #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask)) 50b3c818a4SEric Farman 51b3c818a4SEric Farman #define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 52b3c818a4SEric Farman 53b3c818a4SEric Farman #endif /* _LINUX_CONST_H */ 54