[PATCH 19/22] arm64: dts: qcom: sdm845: 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: 36a80df44b6f ("arm64: dts: sdm845: Add video nodes")
Cc: [email protected]
Signed-off-by: Vikash Garodia <[email protected]>
---
 arch/arm64/boot/dts/qcom/sdm845.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
index b1f6782a3ad9faf16e083d63cb8a6ea1507d4131..442834f394e6412386917b93f12f22069c4633f1 100644
--- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
@@ -898,6 +898,17 @@ fastrpc_mem: fastrpc {
 			size = <0x0 0x1000000>;
 			reusable;
 		};
+
+		/*
+		 * 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>;
+		};
 	};
 
 	adsp_pas: remoteproc-adsp {
@@ -4346,7 +4357,7 @@ venus: video-codec@aa00000 {
 				      "vcodec1_core", "vcodec1_bus";
 			iommus = <&apps_smmu 0x10a0 0x8>,
 				 <&apps_smmu 0x10b0 0x0>;
-			memory-region = <&venus_mem>;
+			memory-region = <&venus_mem>, <&venus_iova>;
 			interconnects = <&mmss_noc MASTER_VIDEO_P0 0 &mem_noc SLAVE_EBI1 0>,
 					<&gladiator_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_VENUS_CFG 0>;
 			interconnect-names = "video-mem", "cpu-cfg";

-- 
2.34.1