blob: c9abbf3e4f68238faaa287dc9fb2222af0e4c236 [file] [log] [blame]
* ARM SMMUv3 Architecture Implementation
The SMMUv3 architecture is a significant departure from previous
revisions, replacing the MMIO register interface with in-memory command
and event queues and adding support for the ATS and PRI components of
the PCIe specification.
** SMMUv3 required properties:
- compatible : Should include:
* "arm,smmu-v3" for any SMMUv3 compliant
implementation. This entry should be last in the
compatible list.
- reg : Base address and size of the SMMU.
- interrupts : Non-secure interrupt list describing the wired
interrupt sources corresponding to entries in
interrupt-names. If no wired interrupts are
present then this property may be omitted.
- interrupt-names : When the interrupts property is present, should
include the following:
* "eventq" - Event Queue not empty
* "priq" - PRI Queue not empty
* "cmdq-sync" - CMD_SYNC complete
* "gerror" - Global Error activated
* "combined" - The combined interrupt is optional,
and should only be provided if the
hardware supports just a single,
combined interrupt line.
If provided, then the combined interrupt
will be used in preference to any others.
- #iommu-cells : See the generic IOMMU binding described in
for details. For SMMUv3, must be 1, with each cell
describing a single stream ID. All possible stream
IDs which a device may emit must be described.
** SMMUv3 optional properties:
- dma-coherent : Present if DMA operations made by the SMMU (page
table walks, stream table accesses etc) are cache
coherent with the CPU.
NOTE: this only applies to the SMMU itself, not
masters connected upstream of the SMMU.
- msi-parent : See the generic MSI binding described in
for a description of the msi-parent property.
- hisilicon,broken-prefetch-cmd
: Avoid sending CMD_PREFETCH_* commands to the SMMU.
- cavium,cn9900-broken-page1-regspace
: Replaces all page 1 offsets used for EVTQ_PROD/CONS,
PRIQ_PROD/CONS register access with page 0 offsets.
Set for Cavium ThunderX2 silicon that doesn't support
SMMU page1 register space.
** Example
smmu@2b400000 {
compatible = "arm,smmu-v3";
reg = <0x0 0x2b400000 0x0 0x20000>;
interrupts = <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>,
interrupt-names = "eventq", "priq", "cmdq-sync", "gerror";
#iommu-cells = <1>;
msi-parent = <&its 0xff0000>;