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3b69eee7a6
Volume boot record is also implemented, it supports reading BTRFS tree structures with upto 64k node size. This support required to change all path in Free Loader to lowercase for better performance. CORE-13769
53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
/*
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* Copied from Linux kernel crypto/crc32c.c
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* Copyright (c) 2004 Cisco Systems, Inc.
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* Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#pragma once
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/*
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* This is the CRC-32C table
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* Generated with:
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* width = 32 bits
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* poly = 0x1EDC6F41
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* reflect input bytes = true
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* reflect output bytes = true
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*/
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static u32 crc32c_table[256];
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/*
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* Steps through buffer one byte at at time, calculates reflected
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* crc using table.
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*/
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static inline u32 crc32c_le(u32 crc, const char *data, size_t length)
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{
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while (length--)
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crc = crc32c_table[(u8)(crc ^ *data++)] ^ (crc >> 8);
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return crc;
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}
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static inline void btrfs_init_crc32c(void)
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{
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int i, j;
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u32 v;
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const u32 poly = 0x82F63B78; /* Bit-reflected CRC32C polynomial */
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for (i = 0; i < 256; i++) {
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v = i;
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for (j = 0; j < 8; j++) {
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v = (v >> 1) ^ ((v & 1) ? poly : 0);
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}
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crc32c_table[i] = v;
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}
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}
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