bits.h (1084B)
1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #pragma once 4 5 #include <stdint.h> 6 7 /* Remove these once we transitioned to C23 across all platforms */ 8 #define UINT32_WIDTH 32 9 #define UINT64_WIDTH 64 10 11 /** 12 * @brief Mask for the little endian nth bit (0-31) in a 32-bit integer. 13 */ 14 #define BIT32(n) (UINT32_C(1) << (n)) 15 16 /** 17 * @brief Mask for the little endian nth bit (0-63) in a 64-bit integer. 18 */ 19 #define BIT64(n) (UINT64_C(1) << (n)) 20 21 /** 22 * @brief Create a contiguous 32-bit wide bitmask starting at bit position @l 23 * and ending at position @h. The range is inclusive, meaning GENMASK32(20, 10) 24 * gives us the 32-bit mask 0x001ffc00. 25 */ 26 #define GENMASK32(h, l) (((~UINT32_C(0)) - (UINT32_C(1) << (l)) + 1) & (~UINT32_C(0) >> (UINT32_WIDTH - 1 - (h)))) 27 28 /** 29 * @brief Create a contiguous 64-bit wide bitmask starting at bit position @l 30 * and ending at position @h. The range is inclusive, meaning GENMASK64(39, 21) 31 * gives us the 64-bit mask 0x000000ffffe00000. 32 */ 33 #define GENMASK64(h, l) (((~UINT64_C(0)) - (UINT64_C(1) << (l)) + 1) & (~UINT64_C(0) >> (UINT64_WIDTH - 1 - (h))))