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35636068ce
Update the PCI Endpoint (EP) device tree binding documentation to include PCIe Gen5 and Gen6 support for the `max-link-speed` property. Similar to the Host Controller binding, the original EP binding limited this value to 1~4 (Gen1~Gen4). With current SoCs requiring Gen5/Gen6 support (e.g., Synopsys/Cadence IP), this change aligns the EP binding with the kernel's PCIe 6.0 capabilities. Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org> Acked-by: Rob Herring (Arm) <robh@kernel.org> Link: https://patch.msgid.link/20250529021026.475861-3-18255117159@163.com
128 lines
4.3 KiB
YAML
128 lines
4.3 KiB
YAML
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/pci/pci-ep.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: PCI Endpoint Controller
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description: |
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Common properties for PCI Endpoint Controller Nodes.
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maintainers:
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- Kishon Vijay Abraham I <kishon@kernel.org>
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- Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
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properties:
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$nodename:
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pattern: "^pcie-ep@"
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iommu-map:
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$ref: /schemas/types.yaml#/definitions/uint32-matrix
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items:
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items:
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- description: Device ID (see msi-map) base
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maximum: 0x7ffff
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- description: phandle to IOMMU
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- description: IOMMU specifier base (currently always 1 cell)
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- description: Number of Device IDs
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maximum: 0x80000
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iommu-map-mask:
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description:
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A mask to be applied to each Device ID prior to being mapped to an
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IOMMU specifier per the iommu-map property.
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$ref: /schemas/types.yaml#/definitions/uint32
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maximum: 0x7ffff
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max-functions:
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description: Maximum number of functions that can be configured
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$ref: /schemas/types.yaml#/definitions/uint8
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minimum: 1
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default: 1
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maximum: 255
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max-virtual-functions:
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description: Array representing the number of virtual functions corresponding to each physical
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function
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$ref: /schemas/types.yaml#/definitions/uint8-array
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minItems: 1
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maxItems: 255
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max-link-speed:
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$ref: /schemas/types.yaml#/definitions/uint32
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enum: [ 1, 2, 3, 4, 5, 6 ]
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msi-map:
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description: |
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Maps a Device ID to an MSI and associated MSI specifier data.
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A PCI Endpoint (EP) can use MSI as a doorbell function. This is achieved by
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mapping the MSI controller's address into PCI BAR<n>. The PCI Root Complex
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can write to this BAR<n>, triggering the EP to generate IRQ. This notifies
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the EP-side driver of an event, eliminating the need for the driver to
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continuously poll for status changes.
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However, the EP cannot rely on Requester ID (RID) because the RID is
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determined by the PCI topology of the host system. Since the EP may be
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connected to different PCI hosts, the RID can vary between systems and is
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therefore not a reliable identifier.
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Each EP can support up to 8 physical functions and up to 65,536 virtual
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functions. To uniquely identify each child device, a device ID is defined
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as
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- Bits [2:0] for the function number (func)
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- Bits [18:3] for the virtual function index (vfunc)
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The resulting device ID is computed as:
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(func & 0x7) | (vfunc << 3)
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The property is an arbitrary number of tuples of
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(device-id-base, msi, msi-base,length).
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Any Device ID id in the interval [id-base, id-base + length) is
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associated with the listed MSI, with the MSI specifier
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(id - id-base + msi-base).
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$ref: /schemas/types.yaml#/definitions/uint32-matrix
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items:
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items:
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- description: The Device ID base matched by the entry
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maximum: 0x7ffff
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- description: phandle to msi-controller node
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- description: (optional) The msi-specifier produced for the first
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Device ID matched by the entry. Currently, msi-specifier is 0 or
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1 cells.
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- description: The length of consecutive Device IDs following the
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Device ID base
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maximum: 0x80000
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msi-map-mask:
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description: A mask to be applied to each Device ID prior to being
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mapped to an msi-specifier per the msi-map property.
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$ref: /schemas/types.yaml#/definitions/uint32
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maximum: 0x7ffff
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num-lanes:
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description: maximum number of lanes
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$ref: /schemas/types.yaml#/definitions/uint32
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minimum: 1
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default: 1
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maximum: 16
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linux,pci-domain:
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description:
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If present this property assigns a fixed PCI domain number to a PCI
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Endpoint Controller, otherwise an unstable (across boots) unique number
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will be assigned. It is required to either not set this property at all
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or set it for all PCI endpoint controllers in the system, otherwise
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potentially conflicting domain numbers may be assigned to endpoint
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controllers. The domain number for each endpoint controller in the system
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must be unique.
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$ref: /schemas/types.yaml#/definitions/uint32
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required:
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- compatible
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additionalProperties: true
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