[PATCH 20/22] arm64: dts: qcom: sm6115: 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: e0511284f0c1 ("arm64: dts: qcom: sm6115: add venus device")
Cc: [email protected]
Signed-off-by: Vikash Garodia <[email protected]>
---
 arch/arm64/boot/dts/qcom/sm6115.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sm6115.dtsi b/arch/arm64/boot/dts/qcom/sm6115.dtsi
index 3520802d1fed57fa722371424cb11a33b277de1a..93f4eb8d18a7161fdee2ab67cdc0b4e8f327e9ee 100644
--- a/arch/arm64/boot/dts/qcom/sm6115.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm6115.dtsi
@@ -532,6 +532,17 @@ rmtfs_mem: memory@89b01000 {
 			qcom,client-id = <1>;
 			qcom,vmid = <QCOM_SCM_VMID_MSS_MSA QCOM_SCM_VMID_NAV>;
 		};
+
+		/*
+		 * 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>;
+		};
 	};
 
 	smp2p-adsp {
@@ -1880,7 +1891,7 @@ venus: video-codec@5a00000 {
 				      "vcodec0_core",
 				      "vcodec0_bus";
 
-			memory-region = <&pil_video_mem>;
+			memory-region = <&pil_video_mem>, <&venus_iova>;
 			iommus = <&apps_smmu 0x860 0x0>,
 				 <&apps_smmu 0x880 0x0>;
 

-- 
2.34.1