[PATCH] arm64: dts: st: add firmware reserved memory to Engicam MicroGEA-STM32MP257

[PATCH] arm64: dts: st: add firmware reserved memory to Engicam MicroGEA-STM32MP257

[Dario Binacchi]

The first 64 MiB of the DDR are used by the secure firmware (TF-M,
Cortex-M33 firmware, BL31 and OP-TEE) and are protected by the RISAF
firewall. Without a reserved-memory node Linux allocates pages there,
and the first access triggers an IAC exception and an OP-TEE panic:

  E/TC:0   stm32_iac_itr:197 IAC exception ID: 137
  Faulty address (IADDR0): 0x80000060
  E/TC:0   Panic at core/drivers/firewall/stm32_iac.c:212 <stm32_iac_itr>

Reserve the region, as done for the stm32mp257f-ev1 board.

Fixes: c5ce8d7bcc78 ("arm64: dts: st: support Engicam MicroGEA-STM32MP257 SoM")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 .../boot/dts/st/stm32mp257-engicam-microgea.dtsi     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea.dtsi b/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea.dtsi
index 5b4287e86def..6cd64587ecdc 100644
--- a/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea.dtsi
+++ b/arch/arm64/boot/dts/st/stm32mp257-engicam-microgea.dtsi
@@ -19,6 +19,18 @@ memory@80000000 {
 		device_type = "memory";
 		reg = <0x0 0x80000000 0x0 0x80000000>;
 	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		fw@80000000 {
+			compatible = "shared-dma-pool";
+			reg = <0x0 0x80000000 0x0 0x4000000>;
+			no-map;
+		};
+	};
 };
 
 &scmi_regu {
---
base-commit: 65ba8f34ec886ec72b2c07ddc8cf3d815c32869d
branch: stm32mp257-engicam-microgea-fw-reserved-memory

-- 
2.43.0