can I split 1 job to both of caam job rings.

[davidmichaeli]

hello, Im working with imx6 caam which has 2 job rings. looking at /proc/interrupts I note that only one job ring is activated at each time. is there a way to use both of the job rings at once for a given cipher? my goal is encrypt more bytes per second , thanks

[raulcardenas-b4]

Hi David,

Your are correct, CAAM does have 2 jobrings. They might be actually running on parallel, depends on the operations, CAAM state, keys being use, etc. However, the kernel does not know anything about the CAAM state, what you are looking at its the CAAM interface to the kernel. CAAM only has one master bus, so it is highly possible that you can see only one ring at a time because it is the one being outputed at that moment. The way to use both rings is by using to different Job descriptors.

Unfourtountalty, your idea to use both rings for a single crypographic operation is not allowed because the job rings do not cooperate. A solution for your idea could be by configuring CAAM to only process one job at time, and setting up the cipher in that job. This would improve the performance, because CAAM wont be doing any context switching and the way to access memory would be sequential.

I hope this helps,

Raul

[Yuri]

  I think, the single Descriptor Controller (DECO) in i.MX6 CAAM does not allow
to implement Your idea.

Have a great day,
Yuri

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------