[PATCH] RM64: dts: ls208xa: Add iommu-map property for pci

-----Original Message-----
From: Marc Zyngier [mailto:marc.zyngier at arm.com]
Sent: Thursday, August 31, 2017 3:02 PM
To: Bharat Bhushan <redacted>; robh+dt at kernel.org;
ark.rutland at arm.com; will.deacon at arm.com; oss at buserror.net; Gang Liu
[off-list ref]; devicetree at vger.kernel.org; linux-arm-
kernel at lists.infradead.org; linux-kernel at vger.kernel.org;
catalin.marinas at arm.com
Subject: Re: [PATCH] RM64: dts: ls208xa: Add iommu-map property for pci

On 31/08/17 10:23, Bharat Bhushan wrote:

quoted

This patch adds iommu-map property for PCIe, which enables SMMU for
these devices on LS208xA devices.

Signed-off-by: Bharat Bhushan <redacted>
---
 arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi

b/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi
index 94cdd30..67cf605 100644

--- a/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls208xa.dtsi

@@ -606,6 +606,7 @@
 			num-lanes = <4>;
 			bus-range = <0x0 0xff>;
 			msi-parent = <&its>;
+			iommu-map = <0 &smmu 0 1>;	/* This is fixed-up by

u-boot */

What does this do when your version of u-boot doesn't fill this in for you?

Good question, frankly I have not thought of this case before.
But if we pass length = 0 in above property then no fixup happen with happen with older u-boot. In this case of_iommu_configure() will return NULL iommu-ops and it switch to swio-tlb. Will that work?

Thanks
-Bharat

Thanks,

	M.
--
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