When entering the "len & sizeof(u32)" branch, len must be less than 8. So after one operation, len must be less than 4. At this time, "len -= sizeof(u32)" is not necessary for 64-bit CPUs. After that, replace `while' loops with equivalent `for' to make the code structure a little bit better by the way. Suggested-by: Maciej W. Rozycki <macro@xxxxxxxxxxx> Link: https://lore.kernel.org/all/alpine.DEB.2.21.2406281713040.43454@xxxxxxxxxxxxxxxxx/ Suggested-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/all/ZtqZpzMH_qMQqzyc@xxxxxxxxxxxxxxxxxxx/ Signed-off-by: Guan Wentao <guanwentao@xxxxxxxxxxxxx> Signed-off-by: WangYuli <wangyuli@xxxxxxxxxxxxx> --- arch/mips/crypto/crc32-mips.c | 70 ++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 33 deletions(-) diff --git a/arch/mips/crypto/crc32-mips.c b/arch/mips/crypto/crc32-mips.c index ec6d58008f8e..2a59b85f88aa 100644 --- a/arch/mips/crypto/crc32-mips.c +++ b/arch/mips/crypto/crc32-mips.c @@ -77,24 +77,26 @@ static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len) { u32 crc = crc_; -#ifdef CONFIG_64BIT - while (len >= sizeof(u64)) { - u64 value = get_unaligned_le64(p); - - CRC32(crc, value, d); - p += sizeof(u64); - len -= sizeof(u64); - } - - if (len & sizeof(u32)) { -#else /* !CONFIG_64BIT */ - while (len >= sizeof(u32)) { -#endif - u32 value = get_unaligned_le32(p); - - CRC32(crc, value, w); - p += sizeof(u32); - len -= sizeof(u32); + if (IS_ENABLED(CONFIG_64BIT)) { + for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) { + u64 value = get_unaligned_le64(p); + + CRC32(crc, value, d); + } + + if (len & sizeof(u32)) { + u32 value = get_unaligned_le32(p); + + CRC32(crc, value, w); + p += sizeof(u32); + } + } else { + for (; len >= sizeof(u32); len -= sizeof(u32)) { + u32 value = get_unaligned_le32(p); + + CRC32(crc, value, w); + p += sizeof(u32); + } } if (len & sizeof(u16)) { @@ -117,24 +119,26 @@ static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len) { u32 crc = crc_; -#ifdef CONFIG_64BIT - while (len >= sizeof(u64)) { - u64 value = get_unaligned_le64(p); + if (IS_ENABLED(CONFIG_64BIT)) { + for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) { + u64 value = get_unaligned_le64(p); - CRC32C(crc, value, d); - p += sizeof(u64); - len -= sizeof(u64); - } + CRC32(crc, value, d); + } - if (len & sizeof(u32)) { -#else /* !CONFIG_64BIT */ - while (len >= sizeof(u32)) { -#endif - u32 value = get_unaligned_le32(p); + if (len & sizeof(u32)) { + u32 value = get_unaligned_le32(p); + + CRC32(crc, value, w); + p += sizeof(u32); + } + } else { + for (; len >= sizeof(u32); len -= sizeof(u32)) { + u32 value = get_unaligned_le32(p); - CRC32C(crc, value, w); - p += sizeof(u32); - len -= sizeof(u32); + CRC32(crc, value, w); + p += sizeof(u32); + } } if (len & sizeof(u16)) { -- 2.43.4