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// SPDX-License-Identifier: GPL-2.0-only
/*
* Aug 8, 2011 Bob Pearson with help from Joakim Tjernlund and George Spelvin
* cleaned up code to current version of sparse and added the slicing-by-8
* algorithm to the closely similar existing slicing-by-4 algorithm.
*
* Oct 15, 2000 Matt Domsch <Matt_Domsch@dell.com>
* Nicer crc32 functions/docs submitted by linux@horizon.com. Thanks!
* Code was from the public domain, copyright abandoned. Code was
* subsequently included in the kernel, thus was re-licensed under the
* GNU GPL v2.
*
* Oct 12, 2000 Matt Domsch <Matt_Domsch@dell.com>
* Same crc32 function was used in 5 other places in the kernel.
* I made one version, and deleted the others.
* There are various incantations of crc32(). Some use a seed of 0 or ~0.
* Some xor at the end with ~0. The generic crc32() function takes
* seed as an argument, and doesn't xor at the end. Then individual
* users can do whatever they need.
* drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
* fs/jffs2 uses seed 0, doesn't xor with ~0.
* fs/partitions/efi.c uses seed ~0, xor's with ~0.
*/
/* see: Documentation/staging/crc32.rst for a description of algorithms */
#include <linux/crc32.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/types.h>
#include "crc32table.h"
static inline u32 __maybe_unused
crc32_le_base(u32 crc, const u8 *p, size_t len)
{
while (len--)
crc = (crc >> 8) ^ crc32table_le[(crc & 255) ^ *p++];
return crc;
}
static inline u32 __maybe_unused
crc32_be_base(u32 crc, const u8 *p, size_t len)
{
while (len--)
crc = (crc << 8) ^ crc32table_be[(crc >> 24) ^ *p++];
return crc;
}
static inline u32 __maybe_unused
crc32c_base(u32 crc, const u8 *p, size_t len)
{
while (len--)
crc = (crc >> 8) ^ crc32ctable_le[(crc & 255) ^ *p++];
return crc;
}
#ifdef CONFIG_CRC32_ARCH
#include "crc32.h" /* $(SRCARCH)/crc32.h */
u32 crc32_optimizations(void)
{
return crc32_optimizations_arch();
}
EXPORT_SYMBOL(crc32_optimizations);
#else
#define crc32_le_arch crc32_le_base
#define crc32_be_arch crc32_be_base
#define crc32c_arch crc32c_base
#endif
u32 crc32_le(u32 crc, const void *p, size_t len)
{
return crc32_le_arch(crc, p, len);
}
EXPORT_SYMBOL(crc32_le);
u32 crc32_be(u32 crc, const void *p, size_t len)
{
return crc32_be_arch(crc, p, len);
}
EXPORT_SYMBOL(crc32_be);
u32 crc32c(u32 crc, const void *p, size_t len)
{
return crc32c_arch(crc, p, len);
}
EXPORT_SYMBOL(crc32c);
#ifdef crc32_mod_init_arch
static int __init crc32_mod_init(void)
{
crc32_mod_init_arch();
return 0;
}
subsys_initcall(crc32_mod_init);
static void __exit crc32_mod_exit(void)
{
}
module_exit(crc32_mod_exit);
#endif
MODULE_DESCRIPTION("CRC32 library functions");
MODULE_LICENSE("GPL");
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