From c0ed490da30e35a5951646ca08e984d7415fdd58 Mon Sep 17 00:00:00 2001
From: Marek Vasut <marek.vasut+renesas@mailbox.org>
Date: Sun, 2 Aug 2026 23:35:50 +0200
Subject: arm64: dts: renesas: ironhide: Describe inline ECC carveouts

The DBSC5 DRAM controller protects DRAM content using inline ECC.
The inline ECC utilizes areas of DRAM for its operation, which are
in the DRAM address range, but must not be accessed or modified.
Describe the inline ECC carveout areas used by the DBSC5 controller
on this hardware as reserved-memory, which must not be accessed.
Include DRAM areas which are unprotected by ECC as well, those are
parts of the DRAM which directly precede the ECC carveout.

In case of high DRAM utilization, unless the inline ECC carveouts
are properly reserved, Linux may use and corrupt the memory used
by the DBSC5 DRAM controller for inline ECC, which would lead to
the system becoming unstable.

Ported from Linux 7.2-rc5 commit
6fa6ee724d8d ("arm64: dts: renesas: ironhide: Describe inline ECC carveouts")

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
 arch/arm/dts/r8a78000-ironhide-u-boot.dtsi | 41 ++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/arm/dts/r8a78000-ironhide-u-boot.dtsi b/arch/arm/dts/r8a78000-ironhide-u-boot.dtsi
index 21b03df849a..2dc8ad7aa6b 100644
--- a/arch/arm/dts/r8a78000-ironhide-u-boot.dtsi
+++ b/arch/arm/dts/r8a78000-ironhide-u-boot.dtsi
@@ -68,6 +68,47 @@
 			reg = <0x0 0x8c400000 0x0 0x02000000>;
 			no-map;
 		};
+
+		/* DRAM controller inline ECC areas */
+		ecc@10cccc0000 {
+			reg = <0x10 0xcccc0000 0x0 0x33340000>;
+			no-map;
+		};
+
+		ecc@12cccc0000 {
+			reg = <0x12 0xcccc0000 0x0 0x33340000>;
+			no-map;
+		};
+
+		ecc@14cccc0000 {
+			reg = <0x14 0xcccc0000 0x0 0x33340000>;
+			no-map;
+		};
+
+		ecc@16cccc0000 {
+			reg = <0x16 0xcccc0000 0x0 0x33340000>;
+			no-map;
+		};
+
+		ecc@18cccc0000 {
+			reg = <0x18 0xcccc0000 0x0 0x33340000>;
+			no-map;
+		};
+
+		ecc@1a66660000 {
+			reg = <0x1a 0x66660000 0x0 0x999a0000>;
+			no-map;
+		};
+
+		ecc@1c66660000 {
+			reg = <0x1c 0x66660000 0x0 0x999a0000>;
+			no-map;
+		};
+
+		ecc@1e66660000 {
+			reg = <0x1e 0x66660000 0x0 0x999a0000>;
+			no-map;
+		};
 	};
 };
 
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