Re: [PATCH] openrisc: Reserve memblock for initrd

[Mike Rapoport]

On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> Recently OpenRISC added support for external initrd images, but I found
> some instability when using larger buildroot initrd images. It turned
> out that I forgot to reserve the memblock space for the initrd image.
> 
> This patch fixes the instability issue by reserving memblock space.
> 
> Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
> ---
>  arch/openrisc/kernel/setup.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> index b18e775f8be3..2c8aa53cc7ba 100644
> --- a/arch/openrisc/kernel/setup.c
> +++ b/arch/openrisc/kernel/setup.c
> @@ -80,6 +80,15 @@ static void __init setup_memory(void)
>  	 */
>  	memblock_reserve(__pa(_stext), _end - _stext);
>  
> +#ifdef CONFIG_BLK_DEV_INITRD
> +	/* Then reserve the initrd, if any */
> +	if (initrd_start && (initrd_end > initrd_start)) {
> +		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> +			ALIGN(initrd_end, PAGE_SIZE) -
> +			ALIGN_DOWN(initrd_start, PAGE_SIZE));
> +	}

The core mm takes care of reserving the entrire pages for the memory
reserved with memblock, so it is not necessary to do it here.

> +#endif /* CONFIG_BLK_DEV_INITRD */
> +
>  	early_init_fdt_reserve_self();
>  	early_init_fdt_scan_reserved_mem();
>  
> -- 
> 2.26.2
> 

-- 
Sincerely yours,
Mike.