Re: [PATCH] powerpc/prom: move the device tree if not in declared memory.

From: Michael Ellerman
Date: Tue Dec 18 2018 - 23:42:58 EST


Christophe Leroy <christophe.leroy@xxxxxx> writes:

> If the device tree doesn't reside in the memory which is declared
> inside it, it has to be moved as well as this memory will not be
> mapped by the kernel.

I worry this will break some obscure platform, but I'll merge it anyway
and we'll see :)

cheers

> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 87a68e2dc531..4181ec715f88 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -124,8 +124,8 @@ static void __init move_device_tree(void)
> size = fdt_totalsize(initial_boot_params);
>
> if ((memory_limit && (start + size) > PHYSICAL_START + memory_limit) ||
> - overlaps_crashkernel(start, size) ||
> - overlaps_initrd(start, size)) {
> + !memblock_is_memory(start + size - 1) ||
> + overlaps_crashkernel(start, size) || overlaps_initrd(start, size)) {
> p = __va(memblock_phys_alloc(size, PAGE_SIZE));
> memcpy(p, initial_boot_params, size);
> initial_boot_params = p;
> --
> 2.13.3