[PATCH] crypto: arm64/gcm-ce - unroll factors to 4-way interleave of aes and ghash

[Will Deacon]

On Tue, Sep 28, 2021 at 11:04:03PM +0200, Ard Biesheuvel wrote:
> On Tue, 28 Sept 2021 at 08:27, Eric Biggers <ebiggers at kernel.org> wrote:
> >
> > On Thu, Sep 23, 2021 at 06:30:25AM +0000, XiaokangQian wrote:
> > > To improve performance on cores with deep piplines such as A72,N1,
> > > implement gcm(aes) using a 4-way interleave of aes and ghash (totally
> > > 8 blocks in parallel), which can make full utilize of pipelines rather
> > > than the 4-way interleave we used currently. It can gain about 20% for
> > > big data sizes such that 8k.
> > >
> > > This is a complete new version of the GCM part of the combined GCM/GHASH
> > > driver, it will co-exist with the old driver, only serve for big data
> > > sizes. Instead of interleaving four invocations of AES where each chunk
> > > of 64 bytes is encrypted first and then ghashed, the new version uses a
> > > more coarse grained approach where a chunk of 64 bytes is encrypted and
> > > at the same time, one chunk of 64 bytes is ghashed (or ghashed and
> > > decrypted in the converse case).
> > >
> > > The table below compares the performance of the old driver and the new
> > > one on various micro-architectures and running in various modes with
> > > various data sizes.
> > >
> > >             |     AES-128       |     AES-192       |     AES-256       |
> > >      #bytes | 1024 | 1420 |  8k | 1024 | 1420 |  8k | 1024 | 1420 |  8k |
> > >      -------+------+------+-----+------+------+-----+------+------+-----+
> > >         A72 | 5.5% |  12% | 25% | 2.2% |  9.5%|  23%| -1%  |  6.7%| 19% |
> > >         A57 |-0.5% |  9.3%| 32% | -3%  |  6.3%|  26%| -6%  |  3.3%| 21% |
> > >         N1  | 0.4% |  7.6%|24.5%| -2%  |  5%  |  22%| -4%  |  2.7%| 20% |
> > >
> > > Signed-off-by: XiaokangQian <xiaokang.qian at arm.com>
> >
> > Does this pass the self-tests, including the fuzz tests which are enabled by
> > CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y?
> >
> 
> Please test both little-endian and big-endian. (Note that you don't
> need a big-endian user space for this - the self tests are executed
> before the rootfs is mounted)
> 
> Also, you will have to rebase this onto the latest cryptodev tree,
> which carries some changes I made recently to this driver.

XiaokangQian -- did you post an updated version of this? It would end up
going via Herbert, but I was keeping half an eye on it and it all seems
to have gone quiet.

Thanks,

Will