mediatek: dts: increase mt7986 ATF reserved memory to 256 kiB

The latest Mediatek open-source Trusted Firmware-A project has
reserved 256 KiB for BL2 and BL31.

Link: https://lore.kernel.org/all/OSBPR01MB16701BDF64C43EF07390C830BC29A@OSBPR01MB1670.jpnprd01.prod.outlook.com/
Signed-off-by: Shiji Yang <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19741
Signed-off-by: Hauke Mehrtens <[email protected]>

diff --git a/target/linux/mediatek/patches-6.12/199-arm64-dts-mediatek-mt7986-increase-ATF-reserved-memo.patch b/target/linux/mediatek/patches-6.12/199-arm64-dts-mediatek-mt7986-increase-ATF-reserved-memo.patch
new file mode 100644 (file)
index 0000000..8cef5ba
--- /dev/null
+++ b/target/linux/mediatek/patches-6.12/199-arm64-dts-mediatek-mt7986-increase-ATF-reserved-memo.patch
@@ -0,0 +1,29 @@
+From 236317dd4e55512933dcdaec3d0b4a0824f5e5bd Mon Sep 17 00:00:00 2001
+From: Shiji Yang <[email protected]>
+Date: Sun, 10 Aug 2025 18:11:01 +0800
+Subject: [PATCH] arm64: dts: mediatek: mt7986: increase ATF reserved memory to
+ 256 kiB
+
+The latest Mediatek open-source Trusted Firmware-A project has
+reserved 256 KiB for BL2 and BL31. It is better to increase the
+reserved memory region in the Linux kernel to protect the data.
+
+Signed-off-by: Shiji Yang <[email protected]>
+---
+ arch/arm64/boot/dts/mediatek/mt7986a.dtsi | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/arm64/boot/dts/mediatek/mt7986a.dtsi
++++ b/arch/arm64/boot/dts/mediatek/mt7986a.dtsi
+@@ -76,9 +76,9 @@
+                       record-size = <0x1000>;
+               };
+ 
+-              /* 192 KiB reserved for ARM Trusted Firmware (BL31) */
++              /* 256 KiB reserved for ARM Trusted Firmware (BL31 + BL32) */
+               secmon_reserved: secmon@43000000 {
+-                      reg = <0 0x43000000 0 0x30000>;
++                      reg = <0 0x43000000 0 0x40000>;
+                       no-map;
+               };
+