On Tue, Mar 16, 2021 at 10:59:02PM -0700, Ilya Lipnitskiy wrote:

From: Chuanhong Guo <redacted>

mt7621 has the following memory map:
0x0-0x1c000000: lower 448m memory
0x1c000000-0x2000000: peripheral registers
0x20000000-0x2400000: higher 64m memory

detect_memory_region in arch/mips/kernel/setup.c only adds the first
memory region and isn't suitable for 512m memory detection because
it may accidentally read the memory area for peripheral registers.

This commit adds memory detection capability for mt7621:
  1. Add the highmem area when 512m is detected.
  2. Guard memcmp from accessing peripheral registers:
     This only happens when a user decided to change kernel load address
     to 256m or higher address. Since this is a quite unusual case, we
     just skip 512m testing and return 256m as memory size.

[...]

I get

WARNING: modpost: vmlinux.o(.text+0x132c): Section mismatch in reference from the function prom_soc_init() to the function .init.text:mt7621_memory_detect()
The function prom_soc_init() references
the function __init mt7621_memory_detect().
This is often because prom_soc_init lacks a __init 
annotation or the annotation of mt7621_memory_detect is wrong.

Can you please fix this ?

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]