On 05/03/18 14:29, Nipun Gupta wrote:
The existing IOMMU bindings cannot be used to specify the relationship
between fsl-mc devices and IOMMUs. This patch adds a binding for
mapping fsl-mc devices to IOMMUs, using a new iommu-parent property.
Given that allowing "msi-parent" for #msi-cells > 1 is merely a
backward-compatibility bodge full of hard-coded assumptions, why would
we want to knowingly introduce a similarly unpleasant equivalent for
IOMMUs? What's wrong with "iommu-map"?
Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx>
---
.../devicetree/bindings/misc/fsl,qoriq-mc.txt | 31 ++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
index 6611a7c..011c7d6 100644
--- a/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
+++ b/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
@@ -9,6 +9,24 @@ blocks that can be used to create functional hardware objects/devices
such as network interfaces, crypto accelerator instances, L2 switches,
etc.
+For an overview of the DPAA2 architecture and fsl-mc bus see:
+drivers/staging/fsl-mc/README.txt
+
+As described in the above overview, all DPAA2 objects in a DPRC share the
+same hardware "isolation context" and a 10-bit value called an ICID
+(isolation context id) is expressed by the hardware to identify
+the requester.
IOW, precisely the case for which "{msi,iommu}-map" exist. Yes, I know
they're currently documented under bindings/pci, but they're not really
intended to be absolutely PCI-specific.
Robin.
+The generic 'iommus' property is cannot be used to describe the relationship
+between fsl-mc and IOMMUs, so an iommu-parent property is used to define
+the same.
+
+For generic IOMMU bindings, see
+Documentation/devicetree/bindings/iommu/iommu.txt.
+
+For arm-smmu binding, see:
+Documentation/devicetree/bindings/iommu/arm,smmu.txt.
+
Required properties:
- compatible
@@ -88,14 +106,27 @@ Sub-nodes:
Value type: <phandle>
Definition: Specifies the phandle to the PHY device node associated
with the this dpmac.
+Optional properties:
+
+- iommu-parent: Maps the devices on fsl-mc bus to an IOMMU.
+ The property specifies the IOMMU behind which the devices on
+ fsl-mc bus are residing.
Example:
+ smmu: iommu@5000000 {
+ compatible = "arm,mmu-500";
+ #iommu-cells = <1>;
+ stream-match-mask = <0x7C00>;
+ ...
+ };
+
fsl_mc: fsl-mc@80c000000 {
compatible = "fsl,qoriq-mc";
reg = <0x00000008 0x0c000000 0 0x40>, /* MC portal base */
<0x00000000 0x08340000 0 0x40000>; /* MC control reg */
msi-parent = <&its>;
+ iommu-parent = <&smmu>;
#address-cells = <3>;
#size-cells = <1>;
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
