60 строки
1.6 KiB
C
60 строки
1.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Try to choose an implementation variant via Kconfig */
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#ifdef CONFIG_CRC32_SLICEBY8
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# define CRC_LE_BITS 64
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# define CRC_BE_BITS 64
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#endif
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#ifdef CONFIG_CRC32_SLICEBY4
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# define CRC_LE_BITS 32
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# define CRC_BE_BITS 32
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#endif
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#ifdef CONFIG_CRC32_SARWATE
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# define CRC_LE_BITS 8
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# define CRC_BE_BITS 8
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#endif
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#ifdef CONFIG_CRC32_BIT
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# define CRC_LE_BITS 1
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# define CRC_BE_BITS 1
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#endif
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/*
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* How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64.
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* For less performance-sensitive, use 4 or 8 to save table size.
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* For larger systems choose same as CPU architecture as default.
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* This works well on X86_64, SPARC64 systems. This may require some
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* elaboration after experiments with other architectures.
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*/
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#ifndef CRC_LE_BITS
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# ifdef CONFIG_64BIT
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# define CRC_LE_BITS 64
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# else
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# define CRC_LE_BITS 32
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# endif
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#endif
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#ifndef CRC_BE_BITS
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# ifdef CONFIG_64BIT
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# define CRC_BE_BITS 64
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# else
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# define CRC_BE_BITS 32
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# endif
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#endif
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/*
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* Little-endian CRC computation. Used with serial bit streams sent
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* lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
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*/
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#if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
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CRC_LE_BITS & CRC_LE_BITS-1
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# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}"
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#endif
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/*
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* Big-endian CRC computation. Used with serial bit streams sent
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* msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
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*/
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#if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
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CRC_BE_BITS & CRC_BE_BITS-1
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# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}"
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#endif
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