Re: [Ocf-linux-users] talitos driver should be preemtive

[Kim P. <kim...@fr...>]

On Thu, 27 May 2010 02:10:12 +0200
" ALEXANDRU IONUT GRAMA" <ai....@al...> wrote:

> Con fecha 26/5/2010, "Kim Phillips" <kim...@fr...>
> escribió:

> >It should be straightforward to convert talitos to support SEC 1.x h/w;
> >it has a different ring buffer mechanism (which, if I knew more about,
> >I'd be able to tell you whether it allowed simultaneous ciphers and
> >hashes)...
> 
> Thank you Kim, I dind't know I shouldn't load the cryptosoft module. In
> this guide(
> http://www.docunext.com/wiki/My_Notes_on_Patching_2.6.22_with_OCF#The_Results
> ),the author uses cryptosoft, and I thought that I should load it. I've
> found a guide of SEC1.x at this website:
> http://cache.freescale.com/files/32bit/doc/user_guide/SEC1SWUG.pdf?fpsp=1&WT_TYPE=Users%20Guides&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation

that's a guide for a different, standalone driver.

> This one give me the the values that I should send to the
> crypto-processor for doing the proper operation, but I don't know the
> meaning of the symbols included in the talitos source code. I want to
> adapt talitos for being fully compatible with SEC 1.x arch, and if my
> changes of the code are apropiate for the project, contribute with them
> to the OCF-project to provide integration with SEC1.x branch. So, David
> and Kim, when you have some time, could you please give me some
> explanation about the meaning of the simbols and functions that you use
> on talitos? It will be very apreciated!!!

even though it was written based on a SEC v2 manual, most of the
references in the talitos driver should coincide with nomenclature used
in the MPC8272 PowerQUICC II Family Reference Manual, Rev. 2, Chapter
38: Security Engine (SEC).

Keep in mind that since mainline linux added support for asynchronous
crypto, a new talitos driver has since been merged:

http://git.kernel.org/?p=linux/kernel/git/herbert/cryptodev-2.6.git;a=blob;f=drivers/crypto/talitos.c;h=637c105f53d262f904230c77b5bc5a5a5234fda7;hb=master

OCF can also utilize this driver through its cryptosoft interface
module, so depending on your license preference (OCF is Dual BSD/GPL,
kernel.org is GPL), it might be worth checking out.

> >> Con fecha 25/5/2010, "David McCullough" <dav...@mc...>
> >> escribió:
> >> 
> >> >
> >> >Jivin Kim Phillips lays it down ...
> >> >> On Wed, 26 May 2010 07:55:51 +1000
> >> >> David McCullough <dav...@Mc...> wrote:
> >> >>
> >> >> >
> >> >> > Jivin Kim Phillips lays it down ...

> >> >> not a kernel pre-emption issue per se; I just wanted to mention it
> >> >> makes it harder to overcome serializing the overhead of sending the
> >> >> request to h/w and back.  Also, newer talitos h/w can perform ciphers
> >> >> and hashes simultaneously (I'm not sure if the 8272 can do that though).
> >> >
> >> >But the 8272 still has a queue for crypto requests right ?  Which means you
> >> >can have several outstanding requests to the HW at any point ?

turns out the sec1.0 in the 8272 has four dma channels, so yes, it can
do a cipher and a hash at the same time.

Cheers,

Kim