[PATCH 07/22] arm64: dts: qcom: sc8280xp: Reserve low IOVA range for Iris

[Vikash Garodia]

Iris 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 Iris node so the IOMMU layer keeps DMA
allocations above that boundary.

Fixes: 3a52eef16b97 ("arm64: dts: qcom: sc8280xp: Add Iris core")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
index fbcfd3883bbb4e465a71e60a2e295f9a4b3c668f..1c624683d003361773b5cd1e95424990e8130b9f 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
@@ -669,6 +669,17 @@ reserved-region@aeb00000 {
 			reg = <0 0xaeb00000 0 0x16600000>;
 			no-map;
 		};
+
+		/*
+		 * The Iris 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.
+		 */
+		iris_iova: iris-iova {
+			iommu-addresses = <&iris 0x0 0x0 0x0 0x25800000>;
+		};
 	};
 
 	smp2p-adsp {
@@ -4266,7 +4277,7 @@ &config_noc SLAVE_VENUS_CFG QCOM_ICC_TAG_ACTIVE_ONLY>,
 
 			operating-points-v2 = <&iris_opp_table>;
 			iommus = <&apps_smmu 0x2a00 0x400>;
-			memory-region = <&pil_video_mem>;
+			memory-region = <&pil_video_mem>, <&iris_iova>;
 
 			status = "disabled";
 

-- 
2.34.1