Re: [PATCH v18 04/15] dt-bindings: PCI: pci-ep: Add support for iommu-map and msi-map

Rob Herring (Arm)
2025-04-15T23:27:56Z

On Mon, 14 Apr 2025 14:30:58 -0400, Frank Li wrote:
> Document the use of (msi|iommu)-map for PCI Endpoint (EP) controllers,
> which can use MSI as a doorbell mechanism. Each EP controller can support
> up to 8 physical functions and 65,536 virtual functions.
>
> Define how to construct device IDs using function bits [2:0] and virtual
> function index bits [31:3], enabling (msi|iommu)-map to associate each
> child device with a specific (msi|iommu)-specifier.
>
> The EP cannot rely on PCI Requester ID (RID) because the RID is determined
> by the PCI topology of the host system. Since the EP may be connected to
> different PCI hosts, the RID can vary between systems and is therefore not
> a reliable identifier.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> Change from v17 to v18
> - mask max value should 0x7ffff
> - order according to property name
>
> Change from v16 to v17
> - new patch
> ---
> Documentation/devicetree/bindings/pci/pci-ep.yaml | 68 +++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>