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