[PATCH 15/22] arm64: dts: qcom: msm8996: Reserve low IOVA range for Venus

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: 902d97a44211 ("arm64: dts: qcom: msm8996: Revamp reserved memory")
Cc: [email protected]
Signed-off-by: Vikash Garodia <[email protected]>
---
 arch/arm64/boot/dts/qcom/msm8996.dtsi | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
index 818e5660df91d9bae0c3077f476b50a28f2baee4..e8a01b4d0c462f51ff4b40af7ea1665f2e231699 100644
--- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
@@ -592,6 +592,18 @@ mdata_mem: mpss-metadata {
 			size = <0x0 0x4000>;
 			no-map;
 		};
+
+		/*
+		 * 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 0x25800000>;
+		};
+
 	};
 
 	smem {
@@ -2427,7 +2439,7 @@ venus: video-codec@c00000 {
 				 <&venus_smmu 0x2c>,
 				 <&venus_smmu 0x2d>,
 				 <&venus_smmu 0x31>;
-			memory-region = <&venus_mem>;
+			memory-region = <&venus_mem>, <&venus_iova>;
 			status = "disabled";
 
 			video-decoder {

-- 
2.34.1