Re: [PATCH for 4.9 11/59] MIPS: fix mem=X@Y commandline processing

[Mathieu Malaterre]

On Thu, Sep 14, 2017 at 5:51 PM, Levin, Alexander (Sasha Levin)
<alexander.levin@xxxxxxxxxxx> wrote:
> From: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
>
> [ Upstream commit 73fbc1eba7ffa3bf0ad12486232a8a1edb4e4411 ]
>
> When a memory offset is specified through the commandline, add the
> memory in range PHYS_OFFSET:Y as reserved memory area.
> Otherwise the bootmem allocator is initialised with low page equal to
> min_low_pfn = PHYS_OFFSET, and in free_all_bootmem will process pages
> starting from min_low_pfn instead of PFN(Y).
>
> Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxx
> Patchwork: https://patchwork.linux-mips.org/patch/14613/
> Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
> ---
>  arch/mips/kernel/setup.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index f66e5ce505b2..38697f25d168 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -589,6 +589,10 @@ static int __init early_parse_mem(char *p)
>                 start = memparse(p + 1, &p);
>
>         add_memory_region(start, size, BOOT_MEM_RAM);
> +
> +       if (start && start > PHYS_OFFSET)
> +               add_memory_region(PHYS_OFFSET, start - PHYS_OFFSET,
> +                               BOOT_MEM_RESERVED);
>         return 0;
>  }
>  early_param("mem", early_parse_mem);

Does not work on MIPS Creator CI20. See:

https://www.spinics.net/lists/stable/msg187229.html