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b5ae12e0ee
Make the CRC32 library export a function crc32_optimizations() which returns flags that indicate which CRC32 functions are actually executing optimized code at runtime. This will be used to determine whether the crc32[c]-$arch shash algorithms should be registered in the crypto API. btrfs could also start using these flags instead of the hack that it currently uses where it parses the crypto_shash_driver_name. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20241202010844.144356-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
119 lines
4.2 KiB
C
119 lines
4.2 KiB
C
/*
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* crc32.h
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* See linux/lib/crc32.c for license and changes
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*/
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#ifndef _LINUX_CRC32_H
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#define _LINUX_CRC32_H
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#include <linux/types.h>
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#include <linux/bitrev.h>
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u32 __pure crc32_le_arch(u32 crc, const u8 *p, size_t len);
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u32 __pure crc32_le_base(u32 crc, const u8 *p, size_t len);
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u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len);
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u32 __pure crc32_be_base(u32 crc, const u8 *p, size_t len);
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u32 __pure crc32c_le_arch(u32 crc, const u8 *p, size_t len);
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u32 __pure crc32c_le_base(u32 crc, const u8 *p, size_t len);
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static inline u32 __pure crc32_le(u32 crc, const u8 *p, size_t len)
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{
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if (IS_ENABLED(CONFIG_CRC32_ARCH))
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return crc32_le_arch(crc, p, len);
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return crc32_le_base(crc, p, len);
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}
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static inline u32 __pure crc32_be(u32 crc, const u8 *p, size_t len)
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{
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if (IS_ENABLED(CONFIG_CRC32_ARCH))
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return crc32_be_arch(crc, p, len);
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return crc32_be_base(crc, p, len);
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}
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/* TODO: leading underscores should be dropped once callers have been updated */
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static inline u32 __pure __crc32c_le(u32 crc, const u8 *p, size_t len)
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{
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if (IS_ENABLED(CONFIG_CRC32_ARCH))
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return crc32c_le_arch(crc, p, len);
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return crc32c_le_base(crc, p, len);
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}
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/*
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* crc32_optimizations() returns flags that indicate which CRC32 library
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* functions are using architecture-specific optimizations. Unlike
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* IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32
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* variants and also whether any needed CPU features are available at runtime.
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*/
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#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */
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#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */
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#define CRC32C_OPTIMIZATION BIT(2) /* __crc32c_le() is optimized */
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#if IS_ENABLED(CONFIG_CRC32_ARCH)
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u32 crc32_optimizations(void);
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#else
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static inline u32 crc32_optimizations(void) { return 0; }
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#endif
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/**
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* crc32_le_combine - Combine two crc32 check values into one. For two
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* sequences of bytes, seq1 and seq2 with lengths len1
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* and len2, crc32_le() check values were calculated
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* for each, crc1 and crc2.
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*
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* @crc1: crc32 of the first block
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* @crc2: crc32 of the second block
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* @len2: length of the second block
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*
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* Return: The crc32_le() check value of seq1 and seq2 concatenated,
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* requiring only crc1, crc2, and len2. Note: If seq_full denotes
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* the concatenated memory area of seq1 with seq2, and crc_full
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* the crc32_le() value of seq_full, then crc_full ==
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* crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
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* with the same initializer as crc1, and crc2 seed was 0. See
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* also crc32_combine_test().
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*/
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u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len);
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static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
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{
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return crc32_le_shift(crc1, len2) ^ crc2;
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}
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/**
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* __crc32c_le_combine - Combine two crc32c check values into one. For two
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* sequences of bytes, seq1 and seq2 with lengths len1
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* and len2, __crc32c_le() check values were calculated
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* for each, crc1 and crc2.
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*
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* @crc1: crc32c of the first block
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* @crc2: crc32c of the second block
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* @len2: length of the second block
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*
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* Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
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* requiring only crc1, crc2, and len2. Note: If seq_full denotes
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* the concatenated memory area of seq1 with seq2, and crc_full
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* the __crc32c_le() value of seq_full, then crc_full ==
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* __crc32c_le_combine(crc1, crc2, len2) when crc_full was
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* seeded with the same initializer as crc1, and crc2 seed
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* was 0. See also crc32c_combine_test().
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*/
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u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len);
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static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2)
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{
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return __crc32c_le_shift(crc1, len2) ^ crc2;
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}
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#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
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/*
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* Helpers for hash table generation of ethernet nics:
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*
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* Ethernet sends the least significant bit of a byte first, thus crc32_le
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* is used. The output of crc32_le is bit reversed [most significant bit
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* is in bit nr 0], thus it must be reversed before use. Except for
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* nics that bit swap the result internally...
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*/
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#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
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#define ether_crc_le(length, data) crc32_le(~0, data, length)
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#endif /* _LINUX_CRC32_H */
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