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From:   Detlev Casanova <detlev.casanova@collabora.com>
To:     linux-kernel@vger.kernel.org
Cc:     Geert Uytterhoeven <geert+renesas@glider.be>,
        Magnus Damm <magnus.damm@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-renesas-soc@vger.kernel.org (open list:ARM/RENESAS ARCHITECTURE),
        devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED
        DEVICE TREE BINDINGS),
        Detlev Casanova <detlev.casanova@collabora.com>
Subject: [PATCH] arm64: dts: renesas: r8a77951: Add reserved memory region
Date:   Mon, 14 Nov 2022 14:48:46 -0500
Message-Id: <20221114194846.108814-1-detlev.casanova@collabora.com>
MIME-Version: 1.0
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The 0x3000000 bytes memory region starting at 0x54000000 is
reserved for the lossy_decompression hardware that will try to
decompress any data written in the region.

Mark the region as no-map to prevent linux from using it as RAM.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 arch/arm64/boot/dts/renesas/r8a77951.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/r8a77951.dtsi b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
index 07c8763c1e77..171833d91313 100644
--- a/arch/arm64/boot/dts/renesas/r8a77951.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
@@ -290,6 +290,18 @@ CPU_SLEEP_1: cpu-sleep-1 {
 		};
 	};
 
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		/* device specific region for Lossy Decompression */
+		lossy_decompress: memory-region@54000000 {
+			no-map;
+			reg = <0x00000000 0x54000000 0x0 0x03000000>;
+		};
+	};
+
 	extal_clk: extal {
 		compatible = "fixed-clock";
 		#clock-cells = <0>;
-- 
2.38.1