lib/crc32: remove unused support for CRC32C combination

crc32c_combine() and crc32c_shift() are no longer used (except by the
KUnit test that tests them), and their current implementation is very
slow.  Remove them.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20250519175012.36581-8-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Biggers 2025-05-19 10:50:09 -07:00 committed by Jakub Kicinski
parent 70c96c7cb9
commit b82f72292a
3 changed files with 0 additions and 35 deletions

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@ -76,29 +76,6 @@ static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
return crc32_le_shift(crc1, len2) ^ crc2; 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) #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
/* /*

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@ -119,12 +119,6 @@ u32 crc32_le_shift(u32 crc, size_t len)
} }
EXPORT_SYMBOL(crc32_le_shift); EXPORT_SYMBOL(crc32_le_shift);
u32 crc32c_shift(u32 crc, size_t len)
{
return crc32_generic_shift(crc, len, CRC32C_POLY_LE);
}
EXPORT_SYMBOL(crc32c_shift);
u32 crc32_be_base(u32 crc, const u8 *p, size_t len) u32 crc32_be_base(u32 crc, const u8 *p, size_t len)
{ {
while (len--) while (len--)

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@ -391,17 +391,11 @@ static u64 crc32c_wrapper(u64 crc, const u8 *p, size_t len)
return crc32c(crc, p, len); return crc32c(crc, p, len);
} }
static u64 crc32c_combine_wrapper(u64 crc1, u64 crc2, size_t len2)
{
return crc32c_combine(crc1, crc2, len2);
}
static const struct crc_variant crc_variant_crc32c = { static const struct crc_variant crc_variant_crc32c = {
.bits = 32, .bits = 32,
.le = true, .le = true,
.poly = 0x82f63b78, .poly = 0x82f63b78,
.func = crc32c_wrapper, .func = crc32c_wrapper,
.combine_func = crc32c_combine_wrapper,
}; };
static void crc32c_test(struct kunit *test) static void crc32c_test(struct kunit *test)