On Mon, Sep 05, 2022 at 07:08:29PM +0200, Thierry Reding wrote: > From: Thierry Reding <treding@xxxxxxxxxx> > > This adds the "iommu-addresses" property to reserved-memory nodes, which > allow describing the interaction of memory regions with IOMMUs. Two use- > cases are supported: > > 1. Static mappings can be described by pairing the "iommu-addresses" > property with a "reg" property. This is mostly useful for adopting > firmware-allocated buffers via identity mappings. One common use- > case where this is required is if early firmware or bootloaders > have set up a bootsplash framebuffer that a display controller is > actively scanning out from during the operating system boot > process. > > 2. If an "iommu-addresses" property exists without a "reg" property, > the reserved-memory node describes an IOVA reservation. Such memory > regions are excluded from the IOVA space available to operating > system drivers and can be used for regions that must not be used to > map arbitrary buffers. > > Each mapping or reservation is tied to a specific device via a phandle > to the device's device tree node. This allows a reserved-memory region > to be reused across multiple devices. > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> > --- > Changes in v8: > - include validation warning fixes that had crept into an unrelated patch > > Changes in v7: > - keep reserved-memory.txt to avoid broken references > > Changes in v6: > - add device phandle to iommu-addresses property in examples > - remove now unused dt-bindings/reserved-memory.h header > > .../reserved-memory/reserved-memory.yaml | 70 +++++++++++++++++++ > 1 file changed, 70 insertions(+) Thanks for being persistent with this. It looks good to me. Reviewed-by: Rob Herring <robh@xxxxxxxxxx> I really don't like new common bindings with only 1 user, so I hope the Asahi folks chime in here. Or really anyone else look at it. Rob
