Re: [PATCH v20 1/5] arm64: Use insert_resource() to simplify code

[Baoquan He <bhe@redhat.com>]

On 01/24/22 at 04:47pm, Zhen Lei wrote:
> insert_resource() traverses the subtree layer by layer from the root node
> until a proper location is found. Compared with request_resource(), the
> parent node does not need to be determined in advance.
> 
> In addition, move the insertion of node 'crashk_res' into function
> reserve_crashkernel() to make the associated code close together.

This is nice cleanup.

Acked-by: Baoquan He <bhe@redhat.com>

> 
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
>  arch/arm64/kernel/setup.c | 17 +++--------------
>  arch/arm64/mm/init.c      |  1 +
>  2 files changed, 4 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index f70573928f1bff0..a81efcc359e4e78 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -225,6 +225,8 @@ static void __init request_standard_resources(void)
>  	kernel_code.end     = __pa_symbol(__init_begin - 1);
>  	kernel_data.start   = __pa_symbol(_sdata);
>  	kernel_data.end     = __pa_symbol(_end - 1);
> +	insert_resource(&iomem_resource, &kernel_code);
> +	insert_resource(&iomem_resource, &kernel_data);
>  
>  	num_standard_resources = memblock.memory.cnt;
>  	res_size = num_standard_resources * sizeof(*standard_resources);
> @@ -246,20 +248,7 @@ static void __init request_standard_resources(void)
>  			res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
>  		}
>  
> -		request_resource(&iomem_resource, res);
> -
> -		if (kernel_code.start >= res->start &&
> -		    kernel_code.end <= res->end)
> -			request_resource(res, &kernel_code);
> -		if (kernel_data.start >= res->start &&
> -		    kernel_data.end <= res->end)
> -			request_resource(res, &kernel_data);
> -#ifdef CONFIG_KEXEC_CORE
> -		/* Userspace will find "Crash kernel" region in /proc/iomem. */
> -		if (crashk_res.end && crashk_res.start >= res->start &&
> -		    crashk_res.end <= res->end)
> -			request_resource(res, &crashk_res);
> -#endif
> +		insert_resource(&iomem_resource, res);
>  	}
>  }
>  
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index db63cc885771a52..90f276d46b93bc6 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -109,6 +109,7 @@ static void __init reserve_crashkernel(void)
>  	kmemleak_ignore_phys(crash_base);
>  	crashk_res.start = crash_base;
>  	crashk_res.end = crash_base + crash_size - 1;
> +	insert_resource(&iomem_resource, &crashk_res);
>  }
>  #else
>  static void __init reserve_crashkernel(void)
> -- 
> 2.25.1
>