Re: [PATCH] of: property: Add device link support for "iommu-map"

[Saravana Kannan]

On Wed, Nov 20, 2019 at 11:00 AM Will Deacon <will@xxxxxxxxxx> wrote:
>
> Commit 8e12257dead7 ("of: property: Add device link support for iommus,
> mboxes and io-channels") added device link support for IOMMU linkages
> described using the "iommus" property. For PCI devices, this property
> is not present and instead the "iommu-map" property is used on the host
> bridge node to map the endpoint RequesterIDs to their corresponding
> IOMMU instance.
>
> Add support for "iommu-map" to the device link supplier bindings so that
> probing of PCI devices can be deferred until after the IOMMU is
> available.
>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> ---
>
> Applies against driver-core/driver-core-next.
> Tested on AMD Seattle (arm64).
>
>  drivers/of/property.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 0fa04692e3cc..37e0d408430d 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1190,10 +1190,20 @@ DEFINE_SIMPLE_PROP(mboxes, "mboxes", "#mbox-cells")
>  DEFINE_SIMPLE_PROP(io_channels, "io-channel", "#io-channel-cells")
>  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
>
> +static struct device_node *parse_iommu_maps(struct device_node *np,
> +                                           const char *prop_name, int index)
> +{
> +       if (strcmp(prop_name, "iommu-map"))
> +               return NULL;
> +
> +       return of_parse_phandle(np, prop_name, (index * 4) + 1);
> +}
> +
>  static const struct supplier_bindings of_supplier_bindings[] = {
>         { .parse_prop = parse_clocks, },
>         { .parse_prop = parse_interconnects, },
>         { .parse_prop = parse_iommus, },
> +       { .parse_prop = parse_iommu_maps, },
>         { .parse_prop = parse_mboxes, },
>         { .parse_prop = parse_io_channels, },
>         { .parse_prop = parse_regulators, },

Heh... a lot smaller than I thought this would be.

Acked-by: Saravana Kannan <saravanak@xxxxxxxxxx>

-Saravana