Re: [PATCH v2 09/10] crypto: caam - add crypto_engine support for RSA algorithms

[Corentin Labbe]

On Tue, Jan 14, 2020 at 10:40:53AM +0000, Iuliana Prodan wrote:
> On 1/14/2020 2:14 AM, Herbert Xu wrote:
> > On Mon, Jan 13, 2020 at 09:48:11AM +0000, Iuliana Prodan wrote:
> >>
> >> Regarding the transfer request to crypto-engine: if sending all requests
> >> to crypto-engine, multibuffer tests, for non-backlogging requests fail
> >> after only 10 requests, since crypto-engine queue has 10 entries.
> > 
> > That isn't right.  The crypto engine should never refuse to accept
> > a request 
> Crypto-engine accepts all request that have the backlog flag, the 
> non-backlog are accepted till the configured limit (of 10).
> 
> > unless the hardware queue is really full.  
> Crypto-engine doesn't check the status of hardware queue.
> The non-backlog requests are dropped after 10 entries.
> 
> > Perhaps the
> > crypto engine code needs to be fixed?
> To me, crypto-engine seems to be made for backlogged request, that's why 
> I'm sending the non-backlog directly to CAAM. The implicit serialization 
> of request in crypto-engine is the bottleneck.
> 
> But, as I said before, I want to update crypto-engine to set queue 
> length when initialize crypto-engine, and remove serialization of 
> requests in crypto-engine by adding knowledge about the underlying hw 
> accelerator (number of request that can be processed in parallel).
> I'll send a RFC with my proposal for crypto-engine enhancements.
> 
> But, until then, I would like to have a backlogging solution in CAAM driver.
> 

Hello

I have already something for queue length and processing in parallel.
I will send it soon.

Regards