Re: [PATCH v51 5/7] firmware: imx: adds miscdev

From: Arnd Bergmann

Date: Wed Sep 16 2026 - 09:23:39 EST


On Mon, Sep 14, 2026, at 21:40, pankaj.gupta@xxxxxxxxxxx wrote:
> From: Pankaj Gupta <pankaj.gupta@xxxxxxx>
>
> Adds the driver for communication interface to secure-enclave, that
> enables exchanging messages with NXP secure enclave HW IP(s)
> like EdgeLock Enclave, from:
> - User-Space Applications via character driver.
>
> ABI documentation for the NXP secure-enclave driver.

I just saw this in linux-next, where it has caused a build failure
for a missing include of linux/slab.h. I hadn't see the series
before (even though it is a v51, which seems crazy), but I am
curious about it now.

> User-space library using this driver:
> - i.MX Secure Enclave library:
> -- URL: https://github.com/nxp-imx/imx-secure-enclave.git,
> - i.MX Secure Middle-Ware:
> -- URL: https://github.com/nxp-imx/imx-smw.git

I assume this will hit the soc tree eventually, so I want to
make sure the reviews have covered all the important aspects here,
and I don't see the answers in the cover letter:

- Who has reviewed the user interface from outside of NXP?
Since this is not a vendor-independent API, I think we have
to be extra careful and make sure this does not duplicate
anything that is already in the standard firmware interfaces.

- Why is there a low-level passthrough to the firmware from
userspace? This looks rather irregular, since it is the kernel's
job to abstract the platform and provide vendor-independent
interfaces. In particular the bit about shared memory and
the generic send/receiv ioctl look like they should not
be there, as those would allow side-channels from userspace.

Arnd