[PATCH 09/22] arm64: dts: qcom: sm8550: 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: 41661853ae8e ("arm64: dts: qcom: sm8550: add iris DT node")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/qcom/qcs8550.dtsi | 11 +++++++++++
 arch/arm64/boot/dts/qcom/sm8550.dtsi  | 13 ++++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/qcs8550.dtsi b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
index f0acdd0b1e9384e684a90f7f49cf63633cd70d53..4306ce69b83da9ef5d80309d5617d723947dc796 100644
--- a/arch/arm64/boot/dts/qcom/qcs8550.dtsi
+++ b/arch/arm64/boot/dts/qcom/qcs8550.dtsi
@@ -158,5 +158,16 @@ mpss_dsm_mem: mpss-dsm-region@d4d00000 {
 			reg = <0x0 0xd4d00000 0x0 0x3300000>;
 			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>;
+		};
 	};
 };
diff --git a/arch/arm64/boot/dts/qcom/sm8550.dtsi b/arch/arm64/boot/dts/qcom/sm8550.dtsi
index 0e701e709235c6e0a5efd7f8447dfa6ef6f6e21f..1eb725a584b26bc11dbc34eeeebf91d3131a916f 100644
--- a/arch/arm64/boot/dts/qcom/sm8550.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8550.dtsi
@@ -1088,6 +1088,17 @@ hyp_ext_reserved_mem: hyp-ext-reserved-region@ff700000 {
 			reg = <0 0xff700000 0 0x100000>;
 			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 {
@@ -3686,7 +3697,7 @@ &config_noc SLAVE_VENUS_CFG QCOM_ICC_TAG_ACTIVE_ONLY>,
 			interconnect-names = "cpu-cfg",
 					     "video-mem";
 
-			memory-region = <&video_mem>;
+			memory-region = <&video_mem>, <&iris_iova>;
 
 			resets = <&gcc GCC_VIDEO_AXI0_CLK_ARES>;
 			reset-names = "bus";

-- 
2.34.1