[PATCH 5/5] lib/crc: arm: Enable arm64's NEON intrinsics implementation of crc64

[Ard Biesheuvel]

On Tue, 31 Mar 2026, at 08:47, Christoph Hellwig wrote:
>>  	depends on CRC64 && CRC_OPTIMIZATIONS
>> +	default y if ARM && KERNEL_MODE_NEON && !(CPU_BIG_ENDIAN && CC_IS_CLANG)
>
> It would be useful to throw in a comment here why it is disabled for
> big-endian on clang.
>

Ack.

>> +#define crc64_be_arch crc64_be_generic
>> +
>> +static inline u64 crc64_nvme_arch(u64 crc, const u8 *p, size_t len)
>> +{
>> +	if (len >= 128 && static_branch_likely(&have_pmull) &&
>> +	    likely(may_use_simd())) {
>> +		do {
>> +			size_t chunk = min_t(size_t, len & ~15, SZ_4K);
>> +
>> +			scoped_ksimd()
>> +				crc = crc64_nvme_arm64_c(crc, p, chunk);
>> +
>> +			p += chunk;
>> +			len -= chunk;
>> +		} while (len >= 128);
>> +	}
>
> From reading the earlier patches, I'll assume arm SIMD code is
> non-preemptable and thus you want the chunking here?  Maybe add
> a little comment explaining that?

Indeed.