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+* Freescale MSI interrupt controller
+Required properties:
+- compatible : compatible list, contains 2 entries,
+ first is "fsl,CHIP-msi", where CHIP is the processor(mpc8610, mpc8572,
+ etc.) and the second is "fsl,mpic-msi" or "fsl,ipic-msi" depending on
+ the parent type.
+- reg : It may contain one or two regions. The first region should contain
+ the address and the length of the shared message interrupt register set.
+ The second region should contain the address of aliased MSIIR register for
+ platforms that have such an alias.
+- msi-available-ranges: use <start count> style section to define which
+ msi interrupt can be used in the 256 msi interrupts. This property is
+ optional, without this, all the 256 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).
+- interrupts : 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.
+- interrupt-parent: the phandle for the interrupt controller
+ that services interrupts for this device. for 83xx cpu, the interrupts
+ are routed to IPIC, and for 85xx/86xx cpu the interrupts are routed
+ to MPIC.
+Optional properties:
+- msi-address-64: 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 below for an
+ explanation.
+ 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>;
+ interrupt-parent = <&mpic>;
+ };
+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.