Subject: Re: [PATCH 06/15] powerpc: fadamp: simplify fadump_reserve_crash_area()

From: Michael Ellerman <[email-masked]>
Date: Thu, 30 Jul 2020 22:15:13 +1000

Mike Rapoport <[email-masked]> writes:
> From: Mike Rapoport <[email-masked]>
>
> fadump_reserve_crash_area() reserves memory from a specified base address
> till the end of the RAM.
>
> Replace iteration through the memblock.memory with a single call to
> memblock_reserve() with appropriate  that will take care of proper memory
                                     ^
                                     parameters?
> reservation.
>
> Signed-off-by: Mike Rapoport <[email-masked]>
> ---
>  arch/powerpc/kernel/fadump.c | 20 +-------------------
>  1 file changed, 1 insertion(+), 19 deletions(-)

I think this looks OK to me, but I don't have a setup to test it easily.
I've added Hari to Cc who might be able to.

But I'll give you an ack in the hope that it works :)

Acked-by: Michael Ellerman <[email-masked]>

> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index 78ab9a6ee6ac..2446a61e3c25 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -1658,25 +1658,7 @@ int __init fadump_reserve_mem(void)
>  /* Preserve everything above the base address */
>  static void __init fadump_reserve_crash_area(u64 base)
>  {
> -	struct memblock_region *reg;
> -	u64 mstart, msize;
> -
> -	for_each_memblock(memory, reg) {
> -		mstart = reg->base;
> -		msize  = reg->size;
> -
> -		if ((mstart + msize) < base)
> -			continue;
> -
> -		if (mstart < base) {
> -			msize -= (base - mstart);
> -			mstart = base;
> -		}
> -
> -		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
> -			(msize >> 20), mstart);
> -		memblock_reserve(mstart, msize);
> -	}
> +	memblock_reserve(base, memblock_end_of_DRAM() - base);
>  }
>  
>  unsigned long __init arch_reserved_kernel_pages(void)
> -- 
> 2.26.2