[PATCH v2] riscv: Cleanup setup_bootmem()

[Palmer Dabbelt]

On Mon, 08 Feb 2021 17:01:51 PST (-0800), wangkefeng.wang at huawei.com wrote:
> After the following patches,
>
>   commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
>   commit 1bd14a66ee52 ("RISC-V: Remove any memblock representing unusable memory area")
>   commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")
>
> some logic is useless, kill the mem_start/start/end and unneeded code.
>
> Reviewed-by: Atish Patra <atish.patra at wdc.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
> ---
> v2:
> - Update changelog and add RB.
>
>  arch/riscv/mm/init.c | 21 ++-------------------
>  1 file changed, 2 insertions(+), 19 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 0b86a1a12da2..241f22348403 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -108,34 +108,17 @@ void __init mem_init(void)
>
>  void __init setup_bootmem(void)
>  {
> -	phys_addr_t mem_start = 0;
> -	phys_addr_t start, dram_end, end = 0;
>  	phys_addr_t vmlinux_end = __pa_symbol(&_end);
>  	phys_addr_t vmlinux_start = __pa_symbol(&_start);
> +	phys_addr_t dram_end = memblock_end_of_DRAM();
>  	phys_addr_t max_mapped_addr = __pa(~(ulong)0);
> -	u64 i;
> -
> -	/* Find the memory region containing the kernel */
> -	for_each_mem_range(i, &start, &end) {
> -		phys_addr_t size = end - start;
> -		if (!mem_start)
> -			mem_start = start;
> -		if (start <= vmlinux_start && vmlinux_end <= end)
> -			BUG_ON(size == 0);
> -	}
>
> -	/*
> -	 * The maximal physical memory size is -PAGE_OFFSET.
> -	 * Make sure that any memory beyond mem_start + (-PAGE_OFFSET) is removed
> -	 * as it is unusable by kernel.
> -	 */
> +	/* The maximal physical memory size is -PAGE_OFFSET. */
>  	memblock_enforce_memory_limit(-PAGE_OFFSET);
>
>  	/* Reserve from the start of the kernel to the end of the kernel */
>  	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
>
> -	dram_end = memblock_end_of_DRAM();
> -
>  	/*
>  	 * memblock allocator is not aware of the fact that last 4K bytes of
>  	 * the addressable memory can not be mapped because of IS_ERR_VALUE

Thanks, this is on for-next.