Re: [PATCH] mm/cma: report base address of single range correctly

[Geert Uytterhoeven]

On Mon, 7 Apr 2025 at 18:54, Frank van der Linden <fvdl@xxxxxxxxxx> wrote:
> The cma_declare_contiguous_nid code was refactored by
> commit c009da4258f9 ("mm, cma: support multiple contiguous
> ranges, if requested"), so that it could use an internal
> function to attempt a single range area first, and then
> try a multi-range one.
>
> However, that meant that the actual base address used for
> the !fixed case (base == 0) wasn't available one level up
> to be printed in the informational message, and it would
> always end up printing a base address of 0 in the boot
> message.
>
> Make the internal function take a phys_addr_t pointer to
> the base address, so that the value is available to the
> caller.
>
> Fixes: c009da4258f9 ("mm, cma: support multiple contiguous ranges, if requested")
> Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-mm/CAMuHMdVWviQ7O9yBFE3f=ev0eVb1CnsQvR6SKtEROBbM6z7g3w@xxxxxxxxxxxxxx/
> Signed-off-by: Frank van der Linden <fvdl@xxxxxxxxxx>

Thanks, this fixes the issue!
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -724,8 +724,10 @@ static int __init __cma_declare_contiguous_nid(phys_addr_t base,
>         ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
>         if (ret)
>                 memblock_phys_free(base, size);
> -
> -       (*res_cma)->nid = nid;
> +       else {
> +               (*res_cma)->nid = nid;
> +               *basep = base;
> +       }

Please add curly braces to the other branch, too.

Or perhaps restructure as:

    if (ret) {
            memblock_phys_free(base, size);
            return ret;
    }

    (*res_cma)->nid = nid;
    *basep = base;

    return 0;

>
>         return ret;
>  }

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds