5478051d74
quantum: util: add bit and bitmask helpers These helpers are handy and can prevent off-by-one errors when working with registers and general low level bit manipulation tasks. The macros themself are inspired by the bits.h macros from the linux kernel source code. Signed-off-by: Stefan Kerkmann <karlk90@pm.me> Co-authored-by: Pascal Getreuer <50221757+getreuer@users.noreply.github.com>
34 lines
1.1 KiB
C
34 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#pragma once
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#include <stdint.h>
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/* Remove these once we transitioned to C23 across all platfroms */
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#define UINT32_WIDTH 32
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#define UINT64_WIDTH 64
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/**
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* @brief Mask for the little endian nth bit (0-31) in a 32-bit integer.
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*/
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#define BIT32(n) (UINT32_C(1) << (n))
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/**
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* @brief Mask for the little endian nth bit (0-63) in a 64-bit integer.
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*/
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#define BIT64(n) (UINT64_C(1) << (n))
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/**
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* @brief Create a contiguous 32-bit wide bitmask starting at bit position @l
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* and ending at position @h. The range is inclusive, meaning GENMASK32(20, 10)
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* gives us the 32-bit mask 0x001ffc00.
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*/
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#define GENMASK32(h, l) (((~UINT32_C(0)) - (UINT32_C(1) << (l)) + 1) & (~UINT32_C(0) >> (UINT32_WIDTH - 1 - (h))))
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/**
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* @brief Create a contiguous 64-bit wide bitmask starting at bit position @l
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* and ending at position @h. The range is inclusive, meaning GENMASK64(39, 21)
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* gives us the 64-bit mask 0x000000ffffe00000.
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*/
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#define GENMASK64(h, l) (((~UINT64_C(0)) - (UINT64_C(1) << (l)) + 1) & (~UINT64_C(0) >> (UINT64_WIDTH - 1 - (h))))
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