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kernel/include/linux/crc32.h
Eric Biggers 68ea3c2ae0 lib/crc32: remove "_le" from crc32c base and arch functions
Following the standardization on crc32c() as the lib entry point for the
Castagnoli CRC32 instead of the previous mix of crc32c(), crc32c_le(),
and __crc32c_le(), make the same change to the underlying base and arch
functions that implement it.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250208024911.14936-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-02-08 20:06:30 -08:00

115 lines
4 KiB
C

/*
* crc32.h
* See linux/lib/crc32.c for license and changes
*/
#ifndef _LINUX_CRC32_H
#define _LINUX_CRC32_H
#include <linux/types.h>
#include <linux/bitrev.h>
u32 crc32_le_arch(u32 crc, const u8 *p, size_t len);
u32 crc32_le_base(u32 crc, const u8 *p, size_t len);
u32 crc32_be_arch(u32 crc, const u8 *p, size_t len);
u32 crc32_be_base(u32 crc, const u8 *p, size_t len);
u32 crc32c_arch(u32 crc, const u8 *p, size_t len);
u32 crc32c_base(u32 crc, const u8 *p, size_t len);
static inline u32 crc32_le(u32 crc, const void *p, size_t len)
{
if (IS_ENABLED(CONFIG_CRC32_ARCH))
return crc32_le_arch(crc, p, len);
return crc32_le_base(crc, p, len);
}
static inline u32 crc32_be(u32 crc, const void *p, size_t len)
{
if (IS_ENABLED(CONFIG_CRC32_ARCH))
return crc32_be_arch(crc, p, len);
return crc32_be_base(crc, p, len);
}
static inline u32 crc32c(u32 crc, const void *p, size_t len)
{
if (IS_ENABLED(CONFIG_CRC32_ARCH))
return crc32c_arch(crc, p, len);
return crc32c_base(crc, p, len);
}
/*
* crc32_optimizations() returns flags that indicate which CRC32 library
* functions are using architecture-specific optimizations. Unlike
* IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32
* variants and also whether any needed CPU features are available at runtime.
*/
#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */
#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */
#define CRC32C_OPTIMIZATION BIT(2) /* crc32c() is optimized */
#if IS_ENABLED(CONFIG_CRC32_ARCH)
u32 crc32_optimizations(void);
#else
static inline u32 crc32_optimizations(void) { return 0; }
#endif
/**
* crc32_le_combine - Combine two crc32 check values into one. For two
* sequences of bytes, seq1 and seq2 with lengths len1
* and len2, crc32_le() check values were calculated
* for each, crc1 and crc2.
*
* @crc1: crc32 of the first block
* @crc2: crc32 of the second block
* @len2: length of the second block
*
* Return: The crc32_le() check value of seq1 and seq2 concatenated,
* requiring only crc1, crc2, and len2. Note: If seq_full denotes
* the concatenated memory area of seq1 with seq2, and crc_full
* the crc32_le() value of seq_full, then crc_full ==
* crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
* with the same initializer as crc1, and crc2 seed was 0. See
* also crc32_combine_test().
*/
u32 crc32_le_shift(u32 crc, size_t len);
static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
{
return crc32_le_shift(crc1, len2) ^ crc2;
}
u32 crc32c_shift(u32 crc, size_t len);
/**
* crc32c_combine - Combine two crc32c check values into one. For two sequences
* of bytes, seq1 and seq2 with lengths len1 and len2, crc32c()
* check values were calculated for each, crc1 and crc2.
*
* @crc1: crc32c of the first block
* @crc2: crc32c of the second block
* @len2: length of the second block
*
* Return: The crc32c() check value of seq1 and seq2 concatenated, requiring
* only crc1, crc2, and len2. Note: If seq_full denotes the concatenated
* memory area of seq1 with seq2, and crc_full the crc32c() value of
* seq_full, then crc_full == crc32c_combine(crc1, crc2, len2) when
* crc_full was seeded with the same initializer as crc1, and crc2 seed
* was 0. See also crc_combine_test().
*/
static inline u32 crc32c_combine(u32 crc1, u32 crc2, size_t len2)
{
return crc32c_shift(crc1, len2) ^ crc2;
}
#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
/*
* Helpers for hash table generation of ethernet nics:
*
* Ethernet sends the least significant bit of a byte first, thus crc32_le
* is used. The output of crc32_le is bit reversed [most significant bit
* is in bit nr 0], thus it must be reversed before use. Except for
* nics that bit swap the result internally...
*/
#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
#define ether_crc_le(length, data) crc32_le(~0, data, length)
#endif /* _LINUX_CRC32_H */