Re: [PATCH] of: unmap memory regions in /memreserve node

From: Rob Herring
Date: Tue Nov 30 2021 - 17:44:03 EST


+linuxppc-dev

On Wed, Nov 24, 2021 at 09:33:47PM +0800, Calvin Zhang wrote:
> Reserved memory regions in /memreserve node aren't and shouldn't
> be referenced elsewhere. So mark them no-map to skip direct mapping
> for them.

I suspect this has a high chance of breaking some platform. There's no
rule a region can't be accessed.

>
> Signed-off-by: Calvin Zhang <calvinzhang.cool@xxxxxxxxx>
> ---
> drivers/of/fdt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index bdca35284ceb..9e88cc8445f6 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -638,7 +638,7 @@ void __init early_init_fdt_scan_reserved_mem(void)
> fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
> if (!size)
> break;
> - early_init_dt_reserve_memory_arch(base, size, false);
> + early_init_dt_reserve_memory_arch(base, size, true);
> }
>
> fdt_scan_reserved_mem();
> --
> 2.30.2
>
>