Instead of having both sha256_blocks_arch() and sha256_blocks_simd(),
instead have just sha256_blocks_arch() which uses the most efficient
implementation that is available in the calling context.
This is simpler, as it reduces the API surface. It's also safer, since
sha256_blocks_arch() just works in all contexts, including contexts
where the FPU/SIMD/vector registers cannot be used. This doesn't mean
that SHA-256 computations *should* be done in such contexts, but rather
we should just do the right thing instead of corrupting a random task's
registers. Eliminating this footgun and simplifying the code is well
worth the very small performance cost of doing the check.
Note: in the case of arm and arm64, what used to be sha256_blocks_arch()
is renamed back to its original name of sha256_block_data_order().
sha256_blocks_arch() is now used for the higher-level dispatch function.
This renaming also required an update to lib/crypto/arm64/sha512.h,
since sha2-armv8.pl is shared by both SHA-256 and SHA-512.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250630160645.3198-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Instead of exposing the arm64-optimized SHA-512 code via arm64-specific
crypto_shash algorithms, instead just implement the sha512_blocks()
library function. This is much simpler, it makes the SHA-512 (and
SHA-384) library functions be arm64-optimized, and it fixes the
longstanding issue where the arm64-optimized SHA-512 code was disabled
by default. SHA-512 still remains available through crypto_shash, but
individual architectures no longer need to handle it.
To match sha512_blocks(), change the type of the nblocks parameter of
the assembly functions from int or 'unsigned int' to size_t. Update the
ARMv8 CE assembly function accordingly. The scalar assembly function
actually already treated it as size_t.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250630160320.2888-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
