diff options
Diffstat (limited to 'Documentation/devicetree/bindings/interrupt-controller/fsl,mpic-msi.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/interrupt-controller/fsl,mpic-msi.yaml | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/interrupt-controller/fsl,mpic-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/fsl,mpic-msi.yaml new file mode 100644 index 000000000000..78d784973661 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/fsl,mpic-msi.yaml @@ -0,0 +1,161 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/interrupt-controller/fsl,mpic-msi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Freescale MSI interrupt controller + +description: | + The Freescale hypervisor and msi-address-64 + ------------------------------------------- + + Normally, PCI devices have access to all of CCSR via an ATMU mapping. The + Freescale MSI driver calculates the address of MSIIR (in the MSI register + block) and sets that address as the MSI message address. + + In a virtualized environment, the hypervisor may need to create an IOMMU + mapping for MSIIR. The Freescale ePAPR hypervisor has this requirement + because of hardware limitations of the Peripheral Access Management Unit + (PAMU), which is currently the only IOMMU that the hypervisor supports. + The ATMU is programmed with the guest physical address, and the PAMU + intercepts transactions and reroutes them to the true physical address. + + In the PAMU, each PCI controller is given only one primary window. The + PAMU restricts DMA operations so that they can only occur within a window. + Because PCI devices must be able to DMA to memory, the primary window must + be used to cover all of the guest's memory space. + + PAMU primary windows can be divided into 256 subwindows, and each + subwindow can have its own address mapping ("guest physical" to "true + physical"). However, each subwindow has to have the same alignment, which + means they cannot be located at just any address. Because of these + restrictions, it is usually impossible to create a 4KB subwindow that + covers MSIIR where it's normally located. + + Therefore, the hypervisor has to create a subwindow inside the same + primary window used for memory, but mapped to the MSIR block (where MSIIR + lives). The first subwindow after the end of guest memory is used for + this. The address specified in the msi-address-64 property is the PCI + address of MSIIR. The hypervisor configures the PAMU to map that address to + the true physical address of MSIIR. + +maintainers: + - J. Neuschäfer <j.ne@posteo.net> + +properties: + compatible: + oneOf: + - enum: + - fsl,mpic-msi + - fsl,mpic-msi-v4.3 + - fsl,ipic-msi + - fsl,vmpic-msi + - fsl,vmpic-msi-v4.3 + - items: + - enum: + - fsl,mpc8572-msi + - fsl,mpc8610-msi + - fsl,mpc8641-msi + - const: fsl,mpic-msi + + reg: + minItems: 1 + items: + - description: Address and length of the shared message interrupt + register set + - description: Address of aliased MSIIR or MSIIR1 register for platforms + that have such an alias. If using MSIIR1, the second region must be + added because different MSI group has different MSIIR1 offset. + + interrupts: + minItems: 1 + maxItems: 16 + description: + Each one of the interrupts here is one entry per 32 MSIs, and routed to + the host interrupt controller. The interrupts should be set as edge + sensitive. If msi-available-ranges is present, only the interrupts that + correspond to available ranges shall be present. + + msi-available-ranges: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + items: + items: + - description: First MSI interrupt in this range + - description: Number of MSI interrupts in this range + description: + Define which MSI interrupt can be used in the 256 MSI interrupts. + If not specified, all the MSI interrupts can be used. + Each available range must begin and end on a multiple of 32 (i.e. no + splitting an individual MSI register or the associated PIC interrupt). + + msi-address-64: + $ref: /schemas/types.yaml#/definitions/uint64 + description: + 64-bit PCI address of the MSIIR register. The MSIIR register is used for + MSI messaging. The address of MSIIR in PCI address space is the MSI + message address. + + This property may be used in virtualized environments where the hypervisor + has created an alternate mapping for the MSIR block. See the top-level + description for an explanation. + +required: + - compatible + - reg + - interrupts + +allOf: + - if: + properties: + compatible: + contains: + enum: + - fsl,mpic-msi-v4.3 + - fsl,vmpic-msi-v4.3 + then: + properties: + interrupts: + minItems: 16 + description: + Version 4.3 implies that there are 16 shared interrupts, and they + are configured through MSIIR1. + + # MPIC v4.3 does not support this property because the 32 interrupts of + # an individual register are not continuous when using MSIIR1. + msi-available-ranges: false + + reg: + minItems: 2 + + else: + properties: + interrupts: + maxItems: 8 + description: + In versions before 4.3, only 8 shared interrupts are available, and + they are configured through MSIIR. + +unevaluatedProperties: false + +examples: + - | + msi@41600 { + compatible = "fsl,mpc8610-msi", "fsl,mpic-msi"; + reg = <0x41600 0x80>; + msi-available-ranges = <0 0x100>; + interrupts = <0xe0 0>, <0xe1 0>, <0xe2 0>, <0xe3 0>, + <0xe4 0>, <0xe5 0>, <0xe6 0>, <0xe7 0>; + }; + + - | + msi@41600 { + compatible = "fsl,mpic-msi-v4.3"; + reg = <0x41600 0x200>, <0x44148 4>; + interrupts = <0xe0 0 0 0>, <0xe1 0 0 0>, <0xe2 0 0 0>, <0xe3 0 0 0>, + <0xe4 0 0 0>, <0xe5 0 0 0>, <0xe6 0 0 0>, <0xe7 0 0 0>, + <0x100 0 0 0>, <0x101 0 0 0>, <0x102 0 0 0>, <0x103 0 0 0>, + <0x104 0 0 0>, <0x105 0 0 0>, <0x106 0 0 0>, <0x107 0 0 0>; + }; + +... |