[PATCH v24 5/9] arm64: kdump: add kdump support

[Pratyush Anand]

On 19/08/2016:10:26:52 AM, AKASHI Takahiro wrote:
> >From 740563e4a437f0d6ecf6e421c91433f9b8f19041 Mon Sep 17 00:00:00 2001
> From: AKASHI Takahiro <takahiro.akashi at linaro.org>
> Date: Fri, 19 Aug 2016 09:57:52 +0900
> Subject: [PATCH] arm64: mark reserved memblock regions explicitly
> 
> ---
>  arch/arm64/kernel/setup.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 38eda13..38589b5 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -205,10 +205,15 @@ static void __init request_standard_resources(void)
>  
>  	for_each_memblock(memory, region) {
>  		res = alloc_bootmem_low(sizeof(*res));
> -		res->name  = "System RAM";
> +		if (memblock_is_nomap(region)) {
> +			res->name  = "reserved";
> +			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +		} else {
> +			res->name  = "System RAM";
> +			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> +		}
>  		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
>  		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
> -		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
>  
>  		request_resource(&iomem_resource, res);


It will help kexec-tools to prevent copying  of any unnecessary data. I
think, then you also need to change phys_offset calculation in kexec-tools. That
should be start of either of first "reserved" or "System RAM" block.

~Pratyush