Re: [PATCH] arm: skip nomap memblocks while finding the lowmem/highmem boundary

[Chester Lin]

On Thu, Aug 22, 2019 at 11:45:34AM +0800, Chester Lin wrote:
> adjust_lowmem_bounds() checks every memblocks in order to find the boundary
> between lowmem and highmem. However some memblocks could be marked as NOMAP
> so they are not used by kernel, which should be skipped while calculating
> the boundary.
> 
> Signed-off-by: Chester Lin <clin@xxxxxxxx>
> ---
>  arch/arm/mm/mmu.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index 426d9085396b..b86dba44d828 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -1181,6 +1181,9 @@ void __init adjust_lowmem_bounds(void)
>  		phys_addr_t block_start = reg->base;
>  		phys_addr_t block_end = reg->base + reg->size;
>  
> +		if (memblock_is_nomap(reg))
> +			continue;
> +
>  		if (reg->base < vmalloc_limit) {
>  			if (block_end > lowmem_limit)
>  				/*
> -- 
> 2.22.0
>

Hi Russell, Mike and Ard,

Per the discussion in the thread "[PATH] efi/arm: fix allocation failure ...",
(https://lkml.org/lkml/2019/8/21/163), I presume that the change to disregard
NOMAP memblocks in adjust_lowmem_bounds() should be separated as a single patch.

Please let me know if any suggestion, thank you.