[PATCH v17 03/10] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()

[Baoquan He]

On 12/10/21 at 02:55pm, Zhen Lei wrote:
> From: Chen Zhou <chenzhou10 at huawei.com>
> 
> To make the functions reserve_crashkernel() as generic,
> replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX.
> 
> Signed-off-by: Chen Zhou <chenzhou10 at huawei.com>
> Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>

If you made change to this patch, please remove the old Acked-by. If you
didn't contribute change, Signed-off-by should be taken off.

Compared this with the version I acked, only see
memblock_free() -> memblock_phys_free() update which should be done
from the rebase.

So ack this one again, and please also consider adding Co-developed-by.

> Tested-by: John Donnelly <John.p.donnelly at oracle.com>
> Tested-by: Dave Kleikamp <dave.kleikamp at oracle.com>
> Acked-by: Baoquan He <bhe at redhat.com>
> ---
>  arch/x86/kernel/setup.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 6424ee4f23da2cf..bb2a0973b98059e 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -489,8 +489,9 @@ static void __init reserve_crashkernel(void)
>  	if (!crash_base) {
>  		/*
>  		 * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
> -		 * crashkernel=x,high reserves memory over 4G, also allocates
> -		 * 256M extra low memory for DMA buffers and swiotlb.
> +		 * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX,
> +		 * also allocates 256M extra low memory for DMA buffers
> +		 * and swiotlb.
>  		 * But the extra memory is not required for all machines.
>  		 * So try low memory first and fall back to high memory
>  		 * unless "crashkernel=size[KMG],high" is specified.
> @@ -518,7 +519,7 @@ static void __init reserve_crashkernel(void)
>  		}
>  	}
>  
> -	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
> +	if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) {
>  		memblock_phys_free(crash_base, crash_size);
>  		return;
>  	}
> -- 
> 2.25.1
>