The initial Zinc patchset, after some mailing list discussion, contained
code to ensure that kernel_fpu_enable would not be kept on for more than
a 4k chunk, since it disables preemption. The choice of 4k isn't totally
scientific, but it's not a bad guess either, and it's what's used in
both the x86 poly1305, blake2s, and nhpoly1305 code already (in the form
of PAGE_SIZE, which this commit corrects to be explicitly 4k for the
former two).
Ard did some back of the envelope calculations and found that
at 5 cycles/byte (overestimate) on a 1ghz processor (pretty slow), 4k
means we have a maximum preemption disabling of 20us, which Sebastian
confirmed was probably a good limit.
Unfortunately the chunking appears to have been left out of the final
patchset that added the glue code. So, this commit adds it back in.
Fixes: 281c7a234197 ("crypto: x86/chacha - expose SIMD ChaCha routine as library function") Fixes: 7338559102c7 ("crypto: arm64/chacha - expose arm64 ChaCha routine as library function") Fixes: 0e4d048643ea ("crypto: arm/chacha - expose ARM ChaCha routine as library function") Fixes: 9a8ee5d159ff ("crypto: x86/poly1305 - wire up faster implementations for kernel") Fixes: 80f996392bcc ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: bb24f38a4cc8 ("crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation") Fixes: eca513abaffd ("crypto: blake2s - x86_64 SIMD implementation") Cc: Eric Biggers <ebiggers@google.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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