[PATCH 13/22] arm64: dts: qcom: kodiak: Reserve low IOVA range for Venus

[Vikash Garodia]

Venus VPU reserves IOVA addresses below 0x25800000 (600MB), primarily for
secure non-pixel buffers. DMA into that range, from any other stream id
would triggers unhandled SMMU page faults that cause spontaneous device
reboots. This is readily reproduced with one or more browser tabs
driving multiple concurrent video decode streams.

Add a reserved-memory IOVA reservation node covering [0, 0x25800000]
and reference it from the venus node so the IOMMU layer keeps DMA
allocations above that boundary.

Fixes: 37613aee2179 ("arm64: dts: qcom: sc7280: Add venus DT node")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/qcom/kodiak.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/kodiak.dtsi b/arch/arm64/boot/dts/qcom/kodiak.dtsi
index f2da3706d5c887e36a55dc5e2f63dc21e940191c..8894149a3d4e238dcb996e25379892949f7302e8 100644
--- a/arch/arm64/boot/dts/qcom/kodiak.dtsi
+++ b/arch/arm64/boot/dts/qcom/kodiak.dtsi
@@ -198,6 +198,17 @@ adsp_rpc_remote_heap_mem: adsp-rpc-remote-heap {
 			alignment = <0x0 0x400000>;
 			size = <0x0 0x800000>;
 		};
+
+		/*
+		 * The Venus VPU reserves IOVA below 0x25800000 (600MB),
+		 * primarily for non-pixel buffers using different Stream IDs.
+		 * DMA into that range triggers unhandled SMMU faults and
+		 * spontaneous reboots, so reserve it to keep IOMMU
+		 * allocations above this boundary.
+		 */
+		venus_iova: venus-iova {
+			iommu-addresses = <&venus 0x0 0x0 0x0 0x25800000>;
+		};
 	};
 
 	cpus {
@@ -5026,7 +5037,7 @@ venus: video-codec@aa00000 {
 			interconnect-names = "cpu-cfg", "video-mem";
 
 			iommus = <&apps_smmu 0x2180 0x20>;
-			memory-region = <&video_mem>;
+			memory-region = <&video_mem>, <&venus_iova>;
 
 			status = "disabled";
 

-- 
2.34.1