Re: [PATCH] powerpc/prom: move the device tree to the right space

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 03/03/2021 à 06:00, Youlin Song a écrit :
> If the device tree has been allocated memory and it will
> be in the memblock reserved space.Obviously it is in a
> valid memory declaration and will be mapped by the kernel.

Could you please provide clearer explanation ? I don't understand what 
you are doing and why.

Especially, the Subject says you move the device tree, but I can't see 
any move in your patch, only some change in the 'if'.

Thanks
Christophe

> 
> Signed-off-by: Youlin Song <syl.loop@gmail.com>
> ---
>   arch/powerpc/kernel/prom.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 9a4797d1d40d..ef5f93e7d7f2 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -121,7 +121,7 @@ static void __init move_device_tree(void)
>   	size = fdt_totalsize(initial_boot_params);
>   
>   	if ((memory_limit && (start + size) > PHYSICAL_START + memory_limit) ||
> -	    !memblock_is_memory(start + size - 1) ||
> +	    (!memblock_is_memory(start + size - 1) && !memblock_is_reserved(start + size - 1)) ||
>   	    overlaps_crashkernel(start, size) || overlaps_initrd(start, size)) {
>   		p = memblock_alloc_raw(size, PAGE_SIZE);
>   		if (!p)