diff mbox series

[v4,2/2] arm64: dts: qcom: sdm845: Extend ranges and describe DMA space

Message ID 20190117042940.25487-3-bjorn.andersson@linaro.org
State Accepted
Commit 9feb667d8674f7f85f5ab6c8d88788a0fbef8d7d
Headers show
Series None | expand

Commit Message

Bjorn Andersson Jan. 17, 2019, 4:29 a.m. UTC 
For devices attached to an IOMMU, translation between IOVA and physical
addresses is no longer 1:1 and dma-ranges should be specified to
describe the available IOVA address space.

On SDM845 the busses are implemented with 36 address bits, so dma-ranges
must be defined to reduce the size of the IOVA address space from the 48
bits supported by the SMMU. Without this DMA allocations may end up with
IOVAs outside the valid range, that gets truncated by the bus between
the device and its translation unit.

Also extend ranges to describe the available address space.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

---

Changes since v3:
- Split this out from patch 1.
- Rewrote commit message from scratch

 arch/arm64/boot/dts/qcom/sdm845.dtsi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
2.18.0
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
index 9867d42dc836..143c5af32e7b 100644
--- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
@@ -353,7 +353,8 @@ 
 	soc: soc {
 		#address-cells = <2>;
 		#size-cells = <2>;
-		ranges = <0 0 0 0 0 0xffffffff>;
+		ranges = <0 0 0 0 0x10 0>;
+		dma-ranges = <0 0 0 0 0x10 0>;
 		compatible = "simple-bus";
 
 		gcc: clock-controller@100000 {