1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __LINUX_BITS_H 3 #define __LINUX_BITS_H 4 5 #include <linux/const.h> 6 #include <vdso/bits.h> 7 #include <uapi/linux/bits.h> 8 #include <asm/bitsperlong.h> 9 10 #define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG)) 11 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) 12 #define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG)) 13 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) 14 #define BITS_PER_BYTE 8 15 16 /* 17 * Create a contiguous bitmask starting at bit position @l and ending at 18 * position @h. For example 19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. 20 */ 21 #if !defined(__ASSEMBLY__) 22 #include <linux/build_bug.h> 23 #define GENMASK_INPUT_CHECK(h, l) \ 24 (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ 25 __is_constexpr((l) > (h)), (l) > (h), 0))) 26 #else 27 /* 28 * BUILD_BUG_ON_ZERO is not available in h files included from asm files, 29 * disable the input check if that is the case. 30 */ 31 #define GENMASK_INPUT_CHECK(h, l) 0 32 #endif 33 34 #define GENMASK(h, l) \ 35 (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) 36 #define GENMASK_ULL(h, l) \ 37 (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) 38 39 #if !defined(__ASSEMBLY__) 40 /* 41 * Missing asm support 42 * 43 * __GENMASK_U128() depends on _BIT128() which would not work 44 * in the asm code, as it shifts an 'unsigned __init128' data 45 * type instead of direct representation of 128 bit constants 46 * such as long and unsigned long. The fundamental problem is 47 * that a 128 bit constant will get silently truncated by the 48 * gcc compiler. 49 */ 50 #define GENMASK_U128(h, l) \ 51 (GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l)) 52 #endif 53 54 #endif /* __LINUX_BITS_H */ 55