Advanced users • Re: IOMMUs on Raspberry Pi 5 (device tree, quantity, and potential PCIe passthrough)

Okay, so given the information I have, this is how the IOMMUs are going to look for each model.

Raspberry Pi 5 (C1 stepping):
IOMMU0 @ 0x5000: VPU (firmware)
IOMMU1 @ 0x5080: DMA + eMMC2 (prob initialized in eeprom)
IOMMU2 @ 0x5100: ISP + HEVC (in device tree)
IOMMU3 @ 0x5180: unused
IOMMU4 @ 0x5200: HVS (prob initialized in eeprom)
IOMMU5 @ 0x5280: PCIe2 (PCIe 2.0 x4) (in device tree)
IOMMU6 @ 0x5300: eMMC0 + sysctrl (whatever that is) (not in base device tree)
IOMMU7 @ 0x5380: unused
IOMMU8 @ 0x5400: PCIe0/PCIe1 (PCIe 3.0 x1) (in device tree?)
IOMMU9 @ 0x5480: unused

Raspberry Pi 5 (D0 stepping):
IOMMU0 @ 0x5000: VPU (firmware)
IOMMU1 @ 0x5080: DMA + eMMC2 (prob initialized in eeprom)
IOMMU2 @ 0x5100: ISP + HEVC + PCIe0/PCIe1 (PCIe 3.0 x1) (in device tree?) (combine: IOMMU8 + IOMMU2)
IOMMU3 @ 0x5300: eMMC0 + sysctrl (whatever that is) (not in base device tree) (rename: IOMMU6 -> IOMMU3)
IOMMU4 @ 0x5200: HVS (prob initialized in eeprom)
IOMMU5 @ 0x5280: PCIe2 (PCIe 2.0 x4) (in device tree)
IOMMU6 @ 0x5300: aliased to IOMMU3?

Does this look right? I'm just making sure before I do the device tree edits. There also appears to be a flag for the dma-region (I'm still trying to figure out what the flag bits mean for each region) that is cleared to group the PCIe interface in the iommu group.

Statistics: Posted by srgb565 — Wed Sep 03, 2025 5:47 pm

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