forked from mirrors/linux
242cdad873
This fixes a regression introduced byfaa16bc404("lib: Use existing define with polynomial"). The cleanup added a dependency on include/linux, which broke the PowerPC boot wrapper/decompresser when KERNEL_XZ is enabled: BOOTCC arch/powerpc/boot/decompress.o In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:233, from arch/powerpc/boot/decompress.c:42: arch/powerpc/boot/../../../lib/xz/xz_crc32.c:18:10: fatal error: linux/crc32poly.h: No such file or directory #include <linux/crc32poly.h> ^~~~~~~~~~~~~~~~~~~ The powerpc decompresser is a hairy corner of the kernel. Even while building a 64-bit kernel it needs to build a 32-bit binary and therefore avoid including files from include/linux. This allows users of the xz library to avoid including headers from 'include/linux/' while still achieving the cleanup of the magic number. Fixes:faa16bc404("lib: Use existing define with polynomial") Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: kbuild test robot <lkp@intel.com> Suggested-by: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Joel Stanley <joel@jms.id.au> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
59 lines
1.2 KiB
C
59 lines
1.2 KiB
C
/*
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* CRC32 using the polynomial from IEEE-802.3
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*
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* Authors: Lasse Collin <lasse.collin@tukaani.org>
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* Igor Pavlov <http://7-zip.org/>
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*
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* This file has been put into the public domain.
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* You can do whatever you want with this file.
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*/
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/*
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* This is not the fastest implementation, but it is pretty compact.
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* The fastest versions of xz_crc32() on modern CPUs without hardware
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* accelerated CRC instruction are 3-5 times as fast as this version,
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* but they are bigger and use more memory for the lookup table.
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*/
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#include "xz_private.h"
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/*
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* STATIC_RW_DATA is used in the pre-boot environment on some architectures.
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* See <linux/decompress/mm.h> for details.
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*/
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#ifndef STATIC_RW_DATA
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# define STATIC_RW_DATA static
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#endif
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STATIC_RW_DATA uint32_t xz_crc32_table[256];
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XZ_EXTERN void xz_crc32_init(void)
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{
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const uint32_t poly = CRC32_POLY_LE;
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uint32_t i;
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uint32_t j;
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uint32_t r;
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for (i = 0; i < 256; ++i) {
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r = i;
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for (j = 0; j < 8; ++j)
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r = (r >> 1) ^ (poly & ~((r & 1) - 1));
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xz_crc32_table[i] = r;
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}
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return;
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}
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XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
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{
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crc = ~crc;
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while (size != 0) {
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crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
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--size;
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}
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return ~crc;
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}
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