On Fri, Jul 2, 2021 at 8:05 AM Dmitry Osipenko <digetx@xxxxxxxxx> wrote:
>
> 23.04.2021 19:32, Thierry Reding пишет:
> > +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list)
> > +{
> > + struct of_phandle_iterator it;
> > + int err;
> > +
> > + of_for_each_phandle(&it, err, dev->of_node, "memory-region", "#memory-region-cells", 0) {
> > + struct iommu_resv_region *region;
> > + struct of_phandle_args args;
> > + struct resource res;
> > +
> > + args.args_count = of_phandle_iterator_args(&it, args.args, MAX_PHANDLE_ARGS);
> > +
> > + err = of_address_to_resource(it.node, 0, &res);
> > + if (err < 0) {
> > + dev_err(dev, "failed to parse memory region %pOF: %d\n",
> > + it.node, err);
> > + continue;
> > + }
> > +
> > + if (args.args_count > 0) {
> > + /*
> > + * Active memory regions are expected to be accessed by hardware during
> > + * boot and must therefore have an identity mapping created prior to the
> > + * driver taking control of the hardware. This ensures that non-quiescent
> > + * hardware doesn't cause IOMMU faults during boot.
> > + */
> > + if (args.args[0] & MEMORY_REGION_IDENTITY_MAPPING) {
> > + region = iommu_alloc_resv_region(res.start, resource_size(&res),
> > + IOMMU_READ | IOMMU_WRITE,
> > + IOMMU_RESV_DIRECT_RELAXABLE);
> > + if (!region)
> > + continue;
> > +
> > + list_add_tail(®ion->list, list);
> > + }
> > + }
> > + }
> > +}
> > +EXPORT_SYMBOL(of_iommu_get_resv_regions);
>
> Any reason why this is not EXPORT_SYMBOL_GPL? I'm curious what is the
> logic behind the OF symbols in general since it looks like half of them
> are GPL.
Generally, new ones are _GPL. Old ones probably predate _GPL.
This one is up to the IOMMU maintainers.
Rob
