diff options
Diffstat (limited to 'Documentation/devicetree/bindings/pci/pci-ep.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/pci/pci-ep.yaml | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pci/pci-ep.yaml b/Documentation/devicetree/bindings/pci/pci-ep.yaml index f75000e3093d..214caa4ec3d5 100644 --- a/Documentation/devicetree/bindings/pci/pci-ep.yaml +++ b/Documentation/devicetree/bindings/pci/pci-ep.yaml @@ -17,6 +17,24 @@ properties: $nodename: pattern: "^pcie-ep@" + iommu-map: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + items: + items: + - description: Device ID (see msi-map) base + maximum: 0x7ffff + - description: phandle to IOMMU + - description: IOMMU specifier base (currently always 1 cell) + - description: Number of Device IDs + maximum: 0x80000 + + iommu-map-mask: + description: + A mask to be applied to each Device ID prior to being mapped to an + IOMMU specifier per the iommu-map property. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 0x7ffff + max-functions: description: Maximum number of functions that can be configured $ref: /schemas/types.yaml#/definitions/uint8 @@ -35,6 +53,56 @@ properties: $ref: /schemas/types.yaml#/definitions/uint32 enum: [ 1, 2, 3, 4 ] + msi-map: + description: | + Maps a Device ID to an MSI and associated MSI specifier data. + + A PCI Endpoint (EP) can use MSI as a doorbell function. This is achieved by + mapping the MSI controller's address into PCI BAR<n>. The PCI Root Complex + can write to this BAR<n>, triggering the EP to generate IRQ. This notifies + the EP-side driver of an event, eliminating the need for the driver to + continuously poll for status changes. + + However, the EP cannot rely on 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. + + Each EP can support up to 8 physical functions and up to 65,536 virtual + functions. To uniquely identify each child device, a device ID is defined + as + - Bits [2:0] for the function number (func) + - Bits [18:3] for the virtual function index (vfunc) + + The resulting device ID is computed as: + + (func & 0x7) | (vfunc << 3) + + The property is an arbitrary number of tuples of + (device-id-base, msi, msi-base,length). + + Any Device ID id in the interval [id-base, id-base + length) is + associated with the listed MSI, with the MSI specifier + (id - id-base + msi-base). + $ref: /schemas/types.yaml#/definitions/uint32-matrix + items: + items: + - description: The Device ID base matched by the entry + maximum: 0x7ffff + - description: phandle to msi-controller node + - description: (optional) The msi-specifier produced for the first + Device ID matched by the entry. Currently, msi-specifier is 0 or + 1 cells. + - description: The length of consecutive Device IDs following the + Device ID base + maximum: 0x80000 + + msi-map-mask: + description: A mask to be applied to each Device ID prior to being + mapped to an msi-specifier per the msi-map property. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 0x7ffff + num-lanes: description: maximum number of lanes $ref: /schemas/types.yaml#/definitions/uint32 |