Re: [PATCH 0/5] crypto: caam - avoid allocating memory at crypto request runtime

[Herbert Xu]

On Thu, Dec 03, 2020 at 09:34:08AM +0100, Ard Biesheuvel wrote:
>
> > CRYPTO_ALG_ALLOCATES_MEMORY flag is limited only to
> > dm-crypt use-cases, which seems to be 4 entries maximum.
> > Therefore in reqsize we allocate memory for maximum 4 entries
> > for src and 4 for dst, aligned.
> > If the driver needs more than the 4 entries maximum, the memory
> > is dynamically allocated, at runtime.
> 
> I'm confused. So the driver does allocate memory in some cases, right?
> So why is it justified to remove CRYPTO_ALG_ALLOCATES_MEMORY?

Because it's only required by dm-crypt, we should modify the
semantics for ALLOCATES_MEMORY such that it only includes those
that require allocations even when the SG list is of 4 entries
or less.

We should update the documentation.

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