lkml.org 
[lkml]   [2019]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 2/2] arm64: dts: imx8mm: Add Crypto CAAM support
On Mon, Dec 9, 2019 at 10:23 AM Horia Geanta <horia.geanta@nxp.com> wrote:
>
> On 12/1/2019 12:52 AM, Adam Ford wrote:
> > The i.MX8M Mini supports the same crypto engine as what is in
> > the i.MX8MQ, but it is not currently present in the device tree,
> > because it may be resricted by security features.
> >
> What exactly are you referring to?

I don't know this hardware very well, but on a different platform, we
needed to make the crypto engines as disabled if they were being
accessed through secure operations which made it unavailable to Linux
without using some special barriers. I didn't have the special
hardware on the other platform that required it that way, so I can't
really explain it well. I know on those special cases, because some
people were accessing these registers through other means, the devices
had to be marked as 'disabled' so to avoid breaking something. Since
I wasn't sure if this was left out of the i.MX8M Mini on purpose, I
let this disabled just in case this hardware platform was also
affected in a similar and people wanting to use it could mark it as
'okay'

adam

>
> > This patch places in into the device tree and marks it as disabled,
> > but anyone not restricting the CAAM with secure mode functions
> > can mark it as enabled.
> >
> Even if - due to export control regulations - CAAM is "trimmed down",
> it loses only the encryption capabilities (hashing etc. still working).
>
> Again, please clarify what you mean by "secure mode functions",
> "security features" etc.
>
> Horia

\
 
 \ /
  Last update: 2019-12-09 17:47    [W:0.041 / U:11.756 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site