mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
5cde7656d0
Allow the kernel builder to choose a crc32* algorithm for the kernel. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Cc: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/*
|
|
* There are multiple 16-bit CRC polynomials in common use, but this is
|
|
* *the* standard CRC-32 polynomial, first popularized by Ethernet.
|
|
* x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0
|
|
*/
|
|
#define CRCPOLY_LE 0xedb88320
|
|
#define CRCPOLY_BE 0x04c11db7
|
|
|
|
/*
|
|
* This is the CRC32c polynomial, as outlined by Castagnoli.
|
|
* x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+
|
|
* x^8+x^6+x^0
|
|
*/
|
|
#define CRC32C_POLY_LE 0x82F63B78
|
|
|
|
/* Try to choose an implementation variant via Kconfig */
|
|
#ifdef CONFIG_CRC32_SLICEBY8
|
|
# define CRC_LE_BITS 64
|
|
# define CRC_BE_BITS 64
|
|
#endif
|
|
#ifdef CONFIG_CRC32_SLICEBY4
|
|
# define CRC_LE_BITS 32
|
|
# define CRC_BE_BITS 32
|
|
#endif
|
|
#ifdef CONFIG_CRC32_SARWATE
|
|
# define CRC_LE_BITS 8
|
|
# define CRC_BE_BITS 8
|
|
#endif
|
|
#ifdef CONFIG_CRC32_BIT
|
|
# define CRC_LE_BITS 1
|
|
# define CRC_BE_BITS 1
|
|
#endif
|
|
|
|
/*
|
|
* How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64.
|
|
* For less performance-sensitive, use 4 or 8 to save table size.
|
|
* For larger systems choose same as CPU architecture as default.
|
|
* This works well on X86_64, SPARC64 systems. This may require some
|
|
* elaboration after experiments with other architectures.
|
|
*/
|
|
#ifndef CRC_LE_BITS
|
|
# ifdef CONFIG_64BIT
|
|
# define CRC_LE_BITS 64
|
|
# else
|
|
# define CRC_LE_BITS 32
|
|
# endif
|
|
#endif
|
|
#ifndef CRC_BE_BITS
|
|
# ifdef CONFIG_64BIT
|
|
# define CRC_BE_BITS 64
|
|
# else
|
|
# define CRC_BE_BITS 32
|
|
# endif
|
|
#endif
|
|
|
|
/*
|
|
* Little-endian CRC computation. Used with serial bit streams sent
|
|
* lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
|
|
*/
|
|
#if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
|
|
CRC_LE_BITS & CRC_LE_BITS-1
|
|
# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}"
|
|
#endif
|
|
|
|
/*
|
|
* Big-endian CRC computation. Used with serial bit streams sent
|
|
* msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
|
|
*/
|
|
#if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
|
|
CRC_BE_BITS & CRC_BE_BITS-1
|
|
# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}"
|
|
#endif
|