[PATCH v4 8/8] ARM: dts: sun9i: Add secure SRAM node used for SMP hotplug

Chen-Yu Tsai wens at csie.org
Wed Jan 17 00:46:54 PST 2018


The A80 stores some magic flags in a portion of the secure SRAM. The
BROM jumps directly to the software entry point set by the SMP code
if the flags are set. This is required for CPU0 hotplugging.

Signed-off-by: Chen-Yu Tsai <wens at csie.org>
Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
 arch/arm/boot/dts/sun9i-a80.dtsi | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/boot/dts/sun9i-a80.dtsi b/arch/arm/boot/dts/sun9i-a80.dtsi
index bf4d40e8359f..b1c86b76ac3c 100644
--- a/arch/arm/boot/dts/sun9i-a80.dtsi
+++ b/arch/arm/boot/dts/sun9i-a80.dtsi
@@ -250,6 +250,25 @@
 		 */
 		ranges = <0 0 0 0x20000000>;
 
+		sram_b: sram at 20000 {
+			/* 256 KiB secure SRAM at 0x20000 */
+			compatible = "mmio-sram";
+			reg = <0x00020000 0x40000>;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0x00020000 0x40000>;
+
+			smp-sram at 1000 {
+				/*
+				 * This is checked by BROM to determine if
+				 * cpu0 should jump to SMP entry vector
+				 */
+				compatible = "allwinner,sun9i-a80-smp-sram";
+				reg = <0x1000 0x8>;
+			};
+		};
+
 		ehci0: usb at a00000 {
 			compatible = "allwinner,sun9i-a80-ehci", "generic-ehci";
 			reg = <0x00a00000 0x100>;
-- 
2.15.1




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