[PATCH 10/33] arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate

Rob Herring robh at kernel.org
Wed Aug 27 09:16:20 PDT 2025


On Wed, Aug 27, 2025 at 10:39 AM Rob Herring <robh at kernel.org> wrote:
>
> On Fri, Aug 22, 2025 at 10:32 AM James Morse <james.morse at arm.com> wrote:
> >
> > Probing MPAM is convoluted. MSCs that are integrated with a CPU may
> > only be accessible from those CPUs, and they may not be online.
> > Touching the hardware early is pointless as MPAM can't be used until
> > the system-wide common values for num_partid and num_pmg have been
> > discovered.

[...]

> > +static int mpam_dt_parse_resources(struct mpam_msc *msc, void *ignored)
> > +{
> > +       int err, num_ris = 0;
> > +       const u32 *ris_idx_p;
> > +       struct device_node *iter, *np;
> > +
> > +       np = msc->pdev->dev.of_node;
> > +       for_each_child_of_node(np, iter) {
>
> Use for_each_available_child_of_node_scoped()
>
> > +               ris_idx_p = of_get_property(iter, "reg", NULL);
>
> This is broken on big endian and new users of of_get_property() are
> discouraged. Use of_property_read_reg().

Err, this is broken on little endian as the DT is big endian.

So this was obviously not tested as I'm confident you didn't test on BE.

Rob



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