[EXT] Re: [PATCH v5 01/11] dt-bindings: arm: fsl: add imx-se-fw binding doc

[Varun Sethi]

Please find comments inline.


Regards
Varun

> -----Original Message-----
> From: Pankaj Gupta <pankaj.gupta at nxp.com>
> Sent: Friday, August 25, 2023 12:56 PM
> To: Varun Sethi <V.Sethi at nxp.com>
> Subject: FW: [EXT] Re: [PATCH v5 01/11] dt-bindings: arm: fsl: add imx-se-fw
> binding doc
>
>
>
> -----Original Message-----
> From: Krzysztof Kozlowski <krzk at kernel.org>
> Sent: Friday, August 25, 2023 12:16 AM
> To: Rob Herring <robh at kernel.org>; Pankaj Gupta <pankaj.gupta at nxp.com>
> Cc: shawnguo at kernel.org; s.hauer at pengutronix.de;
> kernel at pengutronix.de; clin at suse.com; conor+dt at kernel.org;
> pierre.gondois at arm.com; Jacky Bai <ping.bai at nxp.com>; Clark Wang
> <xiaoning.wang at nxp.com>; Wei Fang <wei.fang at nxp.com>; Peng Fan
> <peng.fan at nxp.com>; Bough Chen <haibo.chen at nxp.com>;
> festevam at gmail.com; dl-linux-imx <linux-imx at nxp.com>;
> davem at davemloft.net; krzysztof.kozlowski+dt at linaro.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org; linux-
> kernel at vger.kernel.org; Gaurav Jain <gaurav.jain at nxp.com>;
> alexander.stein at ew.tq-group.com; Sahil Malhotra
> <sahil.malhotra at nxp.com>; Aisheng Dong <aisheng.dong at nxp.com>; Varun
> Sethi <V.Sethi at nxp.com>; Greg Kroah-Hartman
> <gregkh at linuxfoundation.org>
> Subject: [EXT] Re: [PATCH v5 01/11] dt-bindings: arm: fsl: add imx-se-fw
> binding doc
>
> Caution: This is an external email. Please take care when clicking links or
> opening attachments. When in doubt, report the message using the 'Report
> this email' button
>
>
> On 23/08/2023 14:43, Rob Herring wrote:
> >> +                                                          |
> >> +  +------------------------------------------------------ |
> >> +                     |             |           |          |
> >> +  userspace     /dev/ele_muXch0    |           |          |
> >> +                           /dev/ele_muXch1     |          |
> >> +                                         /dev/ele_muXchY  |
> >> +                                                          |
> >> +
> >> +  When a user sends a command to the firmware, it registers its
> >> + device_ctx  as waiter of a response from firmware.
> >> +
> >> +  A user can be registered as receiver of command from the ELE.
> >> +  Create char devices in /dev as channels of the form
> >> + /dev/ele_muXchY with X  the id of the driver and Y for each users.
> >> + It allows to send and receive  messages to the NXP EdgeLock Enclave
> >> + IP firmware on NXP SoC, where current  possible value, i.e., supported
> SoC(s) are imx8ulp, imx93.
> >
> > Looks like a bunch of Linux details which don't belong in the binding.
> >
> > Why do you need your own custom interface to userspace? No one else
> > has a similar feature in their platforms? Something like virtio or
> > rpmsg doesn't work?
>
> +Cc Greg,
>
> I doubt they care. This is some stub-driver to pass messages from user-space
> to the firmware. The interface is undocumented, without examples and no
> user-space user.
>
> Best regards,
> Krzysztof

[Varun] The goal of the driver is to pass messages between firmware and user 
space/kernel consumers.
At the same time driver also enables firmware to use the storage via Linux 
user space. We do have
middleware applications that utilize the driver. These applications leverage 
cryptographic operations and trust
provisioning capabilities offered by the firmware. We can provide references 
to the middleware applications in the next
version of the patch. We do plan to enable the kernel crypto API interface to 
leverage operations provided by the firmware.

The operations that are exposed by the firmware are performance-sensitive and 
session-based (thus serialized). So, the Virtio/rpmsg model
is not suited for our implementation. Also, the secure enclave IP, with which 
the driver facilitates the communication is an opaque block
that doesn't fit the rpmsg model.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 9707 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20230825/29af43ec/attachment.p7s>