Date:   Mon, 24 May 2021 14:51:51 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        herbert@gondor.apana.org.au, will@kernel.org,
        kernel-team@android.com
Subject: Re: [PATCH v5 4/5] crypto: arm64/aes-ccm - remove non-SIMD fallback
 path
Message-ID: <YKwf9wmioRxrKOGO@gmail.com>
References: <20210521102053.66609-1-ardb@kernel.org>
 <20210521102053.66609-5-ardb@kernel.org>
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On Fri, May 21, 2021 at 12:20:52PM +0200, Ard Biesheuvel wrote:
> AES/CCM on arm64 is implemented as a synchronous AEAD, and so it is
> guaranteed by the API that it is only invoked in task or softirq
> context. Since softirqs are now only handled when the SIMD is not
> being used in the task context that was interrupted to service the
> softirq, we no longer need a fallback path. Let's remove it.
> 
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
>  arch/arm64/crypto/aes-ce-ccm-core.S |   1 +
>  arch/arm64/crypto/aes-ce-ccm-glue.c | 181 ++++++--------------
>  2 files changed, 53 insertions(+), 129 deletions(-)

This doesn't just remove the no-SIMD fallback, but it also does some
refactoring.  Notably, it starts to process all the authenticated data in one
kernel_neon_begin() / kernel_neon_end() pair rather than many.  Can you explain
why that is okay now when previously it wasn't, and also split this into two
separate commits?

- Eric