openwrt/target/linux/mpc85xx/patches-5.15/150-arch-powerpc-simpleboot-prevent-overwrite-of-CPU1-sp.patch
David Bauer de37b56cdb 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>
(cherry picked from commit 57d7382cb1)
2023-12-04 01:10:32 +01:00

42 lines
1.4 KiB
Diff

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"));