On 13/12/2022 15:07, 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.
>
> Reported-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> Fixes: 6c5a9dc2481b ("remoteproc: qcom: Make secure world call for mem ownership switch")
> Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
> ---
Thank you for your patch. There is something to discuss/improve.
>
> return ret < 0 ? ret : 0;
> @@ -1882,6 +1899,26 @@ static int q6v5_alloc_memory_region(struct q6v5 *qproc)
> qproc->mpss_phys = qproc->mpss_reloc = r.start;
> qproc->mpss_size = resource_size(&r);
>
> + if (!child) {
> + node = of_parse_phandle(qproc->dev->of_node, "memory-region", 2);
> + } else {
> + child = of_get_child_by_name(qproc->dev->of_node, "metadata");
Bindings do not allow to have child "metadata", do they?
> + node = of_parse_phandle(child, "memory-region", 0);
> + of_node_put(child);
> + }
> +
> + if (!node)
> + return 0;
> +
> + ret = of_address_to_resource(node, 0, &r);
> + of_node_put(node);
> + if (ret) {
> + dev_err(qproc->dev, "unable to resolve metadata region\n");
> + return ret;
> + }
> +
> + qproc->mdata_phys = r.start;
> +
> return 0;
> }
>
Best regards,
Krzysztof
