55 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef __LINUX_BITS_H3#define __LINUX_BITS_H4 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 815 16/*17 * Create a contiguous bitmask starting at bit position @l and ending at18 * position @h. For example19 * 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#else27/*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) 032#endif33 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 support42 *43 * __GENMASK_U128() depends on _BIT128() which would not work44 * in the asm code, as it shifts an 'unsigned __init128' data45 * type instead of direct representation of 128 bit constants46 * such as long and unsigned long. The fundamental problem is47 * that a 128 bit constant will get silently truncated by the48 * gcc compiler.49 */50#define GENMASK_U128(h, l) \51 (GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))52#endif53 54#endif /* __LINUX_BITS_H */55