[PATCH 14/22] arm64: dts: qcom: msm8916: 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: 16bd6c8205ac ("arm64: dts: qcom: msm8916: Add Venus video codec support")
Cc: [email protected]
Signed-off-by: Vikash Garodia <[email protected]>
---
 arch/arm64/boot/dts/qcom/msm8916.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index e39743e22043894955fddc17f04ed859fede5aa9..b9f63d9f2c775da210e8552c530f4ce47341c53c 100644
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -114,6 +114,17 @@ mba_mem: mba {
 			no-map;
 			status = "disabled";
 		};
+
+		/*
+		 * 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>;
+		};
 	};
 
 	clocks {
@@ -1834,7 +1845,7 @@ venus: video-codec@1d00000 {
 				 <&gcc GCC_VENUS0_AXI_CLK>;
 			clock-names = "core", "iface", "bus";
 			iommus = <&apps_iommu 5>;
-			memory-region = <&venus_mem>;
+			memory-region = <&venus_mem>, <&venus_iova>;
 			status = "disabled";
 		};
 

-- 
2.34.1