Some z/Architecture processors can compute a SHA-3 digest in a single
instruction. arch/s390/crypto/ already uses this capability to optimize
the SHA-3 crypto_shash algorithms.
Use this capability to implement the sha3_224(), sha3_256(), sha3_384(),
and sha3_512() library functions too.
SHA3-256 benchmark results provided by Harald Freudenberger
(https://lore.kernel.org/r/4188d18bfcc8a64941c5ebd8de10ede2@linux.ibm.com/)
on a z/Architecture machine with "facility 86" (MSA level 12):
Length (bytes) Before (MB/s) After (MB/s)
============== ============= ============
16 212 225
64 820 915
256 1850 3350
1024 5400 8300
4096 11200 11300
Note: the original data from Harald was given in the form of a graph for
each length, showing the distribution of throughputs from 500 runs. I
guesstimated the peak of each one.
Harald also reported that the generic SHA-3 code was at most 259 MB/s
(https://lore.kernel.org/r/c39f6b6c110def0095e5da5becc12085@linux.ibm.com/).
So as expected, the earlier commit that optimized sha3_absorb_blocks()
and sha3_keccakf() is the more important one; it optimized the Keccak
permutation which is the most performance-critical part of SHA-3.
Still, this additional commit does notably improve performance further
on some lengths.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20251026055032.1413733-13-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
862445d3b9