From: Adam Ford <aford173@gmail.com>
To: Horia Geanta <horia.geanta@nxp.com>
Cc: "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Shawn Guo <shawnguo@kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
dl-linux-imx <linux-imx@nxp.com>,
Aymen Sghaier <aymen.sghaier@nxp.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] arm64: dts: imx8mm: Add Crypto CAAM support
Date: Mon, 9 Dec 2019 10:47:14 -0600 [thread overview]
Message-ID: <CAHCN7x+roEAmteNLT9KkLxPvL6AFFHMUW=J_cLcSdE50kODZQQ@mail.gmail.com> (raw)
In-Reply-To: <VI1PR0402MB348586BEDA9BE13CEB10C75698580@VI1PR0402MB3485.eurprd04.prod.outlook.com>
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
next prev parent reply other threads:[~2019-12-09 16:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-30 22:51 [PATCH 1/2] crypto: caam: Change the i.MX8MQ check support all i.MX8M variants Adam Ford
2019-11-30 22:51 ` [PATCH 2/2] arm64: dts: imx8mm: Add Crypto CAAM support Adam Ford
2019-12-09 16:23 ` Horia Geanta
2019-12-09 16:47 ` Adam Ford [this message]
2019-12-11 14:36 ` Schrempf Frieder
2019-12-04 11:38 ` [PATCH 1/2] crypto: caam: Change the i.MX8MQ check support all i.MX8M variants Schrempf Frieder
2019-12-06 19:55 ` Adam Ford
2019-12-10 7:56 ` Horia Geanta
2019-12-11 14:23 ` Schrempf Frieder
2019-12-11 14:27 ` Adam Ford
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