Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC updates from Eric Biggers:

- Several improvements related to crc_kunit, to align with the standar

Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC updates from Eric Biggers:

- Several improvements related to crc_kunit, to align with the standard
KUnit conventions and make it easier for developers and CI systems to
run this test suite

- Add an arm64-optimized implementation of CRC64-NVME

- Remove unused code for big endian arm64

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
lib/crc: arm64: Simplify intrinsics implementation
lib/crc: arm64: Use existing macros for kernel-mode FPU cflags
lib/crc: arm64: Drop unnecessary chunking logic from crc64
lib/crc: arm64: Assume a little-endian kernel
lib/crc: arm64: add NEON accelerated CRC64-NVMe implementation
lib/crc: arm64: Drop check for CONFIG_KERNEL_MODE_NEON
crypto: crc32c - Remove another outdated comment
crypto: crc32c - Remove more outdated usage information
kunit: configs: Enable all CRC tests in all_tests.config
lib/crc: tests: Add a .kunitconfig file
lib/crc: tests: Add CRC_ENABLE_ALL_FOR_KUNIT
lib/crc: tests: Make crc_kunit test only the enabled CRC variants

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lib/crc: arm64: Drop unnecessary chunking logic from crc64

On arm64, kernel mode NEON executes with preemption enabled, so there is
no need to chunk the input by hand.

Signed-off-by: Ard Biesheuvel

lib/crc: arm64: Drop unnecessary chunking logic from crc64

On arm64, kernel mode NEON executes with preemption enabled, so there is
no need to chunk the input by hand.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260330144630.33026-8-ardb@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

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lib/crc: arm64: add NEON accelerated CRC64-NVMe implementation

Implement an optimized CRC64 (NVMe) algorithm for ARM64 using NEON
Polynomial Multiply Long (PMULL) instructions. The generic shift-and

lib/crc: arm64: add NEON accelerated CRC64-NVMe implementation

Implement an optimized CRC64 (NVMe) algorithm for ARM64 using NEON
Polynomial Multiply Long (PMULL) instructions. The generic shift-and-XOR
software implementation is slow, which creates a bottleneck in NVMe and
other storage subsystems.

The acceleration is implemented using C intrinsics (<arm_neon.h>) rather
than raw assembly for better readability and maintainability.

Key highlights of this implementation:
- Uses 4KB chunking inside scoped_ksimd() to avoid preemption latency
spikes on large buffers.
- Pre-calculates and loads fold constants via vld1q_u64() to minimize
register spilling.
- Benchmarks show the break-even point against the generic implementation
is around 128 bytes. The PMULL path is enabled only for len >= 128.

Performance results (kunit crc_benchmark on Cortex-A72):
- Generic (len=4096): ~268 MB/s
- PMULL (len=4096): ~1556 MB/s (nearly 6x improvement)

Signed-off-by: Demian Shulhan <demyansh@gmail.com>
Link: https://lore.kernel.org/r/20260329074338.1053550-1-demyansh@gmail.com
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

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