Re: [PATCH V4 00/11] Fix XPU violation during modem metadata authentication

[Will Deacon]

Hi Sibi,

On Tue, Jan 17, 2023 at 02:28:29PM +0530, Sibi Sankar wrote:
> The memory region allocated using dma_alloc_attr with no kernel mapping
> attribute set would still be a part of the linear kernel map. Any access
> to this region by the application processor after assigning it to the
> remote Q6 will result in a XPU violation. Fix this by replacing the
> dynamically allocated memory region with a no-map carveout and unmap the
> modem metadata memory region before passing control to the remote Q6.
> The addition of the carveout and memunmap is required only on SoCs that
> mandate memory protection before transferring control to Q6, hence the
> driver falls back to dynamic memory allocation in the absence of the
> modem metadata carveout.

[...]

>   remoteproc: qcom_q6v5_mss: Use a carveout to authenticate modem
>     headers

With this change now merged, am I ok to downgrade the arm64
arch_dma_prep_coherent() back to a clean?

Thanks,

Will