mpc85xx: increase available RAM on Extreme Networks WS-AP3825i

The system-mamory size was page-aligned prior to this commit, only
enabling to use 192MB of system memory of the 256 available.

This was due to the system-memory being manually shrinked to reserve the
upper 1MB for the second-core bootpage in the loader as well as the OS.

Fix this properly in the loader and in Linux using reserved-memory
definitions. This enables the device to use 250MB of system memory.

Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/mpc85xx/files/arch/powerpc/boot/dts/ws-ap3825i.dts

@@ -9,6 +9,9 @@
 	model = "Extreme Networks WS-AP3825i";
 	compatible = "extreme-networks,ws-ap3825i";
 
+	#address-cells = <2>;
+	#size-cells = <2>;
+
 	aliases {
 		ethernet0 = &enet0;
 		ethernet1 = &enet2;
@@ -301,8 +304,19 @@
 	};
 
 	memory {
-		/* Reserve upper MB for second-core-bootpage */
+		reg = <0x0 0x0 0x0 0x10000000>;
-		reg = <0x0 0x0 0x0 0xff00000>;
+	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		cpu1-bootpage@e000000 {
+			/* Reserve upper 1 MB for second-core-bootpage */
+			reg = <0x0 0xff00000 0x0 0x100000>;
+			no-map;
+		};
 	};
 
 	soc@ffe00000 {

target/linux/mpc85xx/patches-5.15/150-arch-powerpc-simpleboot-prevent-overwrite-of-CPU1-sp.patch

@@ -0,0 +1,41 @@
+From 5f856ccc34df25060d36a5a81b7b45b574d86e35 Mon Sep 17 00:00:00 2001
+From: David Bauer <mail@david-bauer.net>
+Date: Sun, 3 Dec 2023 20:09:24 +0100
+Subject: [PATCH] arch: powerpc: simpleboot: prevent overwrite of CPU1
+ spin-table
+
+Don't overwrite the spin-table of additional CPU cores with loader-heap.
+
+U-Boot places the spin-table for CPU1 on P1020 SoCs in the top 1MB of
+system-memory. Instead of parsing reserved-memory (which would be
+considerable more work), reduce the available system-memory for the
+loader by 1MB.
+
+This prevents the loader from overwriting the spin-table of
+additional CPU cores on these platforms.
+
+Linux itself needs to be made aware by this using reserved-memory
+definitions.
+
+This patch is required for using CPU1 on the Extreme Networks
+WS-AP3825i.
+
+Signed-off-by: David Bauer <mail@david-bauer.net>
+---
+ arch/powerpc/boot/simpleboot.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/arch/powerpc/boot/simpleboot.c
++++ b/arch/powerpc/boot/simpleboot.c
+@@ -65,6 +65,11 @@ void platform_init(unsigned long r3, uns
+ 	if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
+ 		memsize64 = 0xffffffff;
+ 
++	/* Reserve upper 1 MB of memory for CPU1 spin-table */
++	if (memsize64 > 0x100000) {
++		memsize64 = memsize64 - 0x100000;
++	}
++
+ 	/* finally, setup the timebase */
+ 	node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
+ 					     "cpu", sizeof("cpu"));