[PATCH v3 11/13] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN

[Herbert Xu]

On Mon, Nov 07, 2022 at 09:05:04AM +0000, Catalin Marinas wrote:
>
> Well, it does ensure that the __alignof__ and sizeof structures like
> crypto_alg and aead_request is still 128 after this change. A kmalloc()
> of a size multiple of 128 returns a 128-byte aligned object. So the aim
> is just to keep the current binary layout/alignment to 128 on arm64. In
> theory, no functional change.

Changing CRYPTO_MINALIGN to 128 does not cause structures that are
smaller than 128 bytes to magically become larger than 128 bytes.
All it does is declare to the compiler that it may assume that
these pointers are 128-byte aligned (which is obviously untrue
if kmalloc does not guarantee that).

So I don't see how this changes anything in practice.  Buffers
that required bouncing prior to your change will still require
bouncing.

If you're set on doing it this way then I can proceed with the
original patch-set to change the drivers.  I've just been putting
it off because it seems that you guys weren't quite decided on
which way to go.

Cheers,
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt