Re: crypto API and IBM z990 hardware support

[James Morris <jmorris@intercode.com.au>]

On Thu, 3 Jul 2003, Arnd Bergmann wrote:

> For built-in drivers, link order decides which implementation is 
> preferred. Consequently, hardware crypto drivers need to come before
> software implementations and must not register themselves if the 
> hardware is not found at initcall time.
> 
> For the module case, the aes-z990.o module could declare
> 'MODULE_ALIAS(aes-hw);', the simple patch below makes sure
> that any aes-hw module is preferred to the software aes
> module. If there is more than one hardware implementation
> available for an architecture, either the autoloader can be
> extended further, or modprobe has to be configured
> appropriately.

While this looks like it will work fine for the z990, it is a special case 
which does not address other requirements for hardware support (some 
initial requirements are listed at 
http://www.intercode.com.au/jamesm/crypto/hardware_notes.txt).

I'm not enthusiastic about adding infrastructure which is really just a
hack for some quaint hardware, and probably does not work towards
addressing more common hardware requirements.


- James
-- 
James Morris
<jmorris@intercode.com.au>