linux-kernel - Re: [PATCH -v2 09/10] m68k,mm: Fully initialize the page-table allocator

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Date:   Fri, 7 Feb 2020 11:58:42 +0100
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-m68k <linux-m68k@...ts.linux-m68k.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Will Deacon <will@...nel.org>,
        Michael Schmitz <schmitzmic@...il.com>,
        Greg Ungerer <gerg@...ux-m68k.org>
Subject: Re: [PATCH -v2 09/10] m68k,mm: Fully initialize the page-table allocator

Hoi Peter,

Thanks for your patch!

On Fri, Jan 31, 2020 at 1:56 PM Peter Zijlstra <peterz@...radead.org> wrote:
> Also iterate the PMD tables to populate the PTE table allocator. This
> also fully replaces the previous zero_pgtable hack.

As no code is being removed in this patch, does this mean this case was
broken since "[PATCH 06/10] m68k,mm: Improve kernel_page_table()"?

> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> ---
>  arch/m68k/mm/init.c |   13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> --- a/arch/m68k/mm/init.c
> +++ b/arch/m68k/mm/init.c
> @@ -120,7 +120,7 @@ void free_initmem(void)
>  static inline void init_pointer_tables(void)
>  {
>  #if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE)
> -       int i;
> +       int i, j;
>
>         /* insert pointer tables allocated so far into the tablelist */
>         init_pointer_table(kernel_pg_dir, TABLE_PGD);
> @@ -133,6 +133,17 @@ static inline void init_pointer_tables(v
>
>                 pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]);
>                 init_pointer_table(pmd_dir, TABLE_PMD);
> +
> +               for (j = 0; j < PTRS_PER_PMD; j++) {
> +                       pmd_t *pmd = &pmd_dir[j];
> +                       pte_t *pte_dir;
> +
> +                       if (!pmd_present(*pmd))
> +                               continue;
> +
> +                       pte_dir = (pte_t *)__pmd_page(*pmd);
> +                       init_pointer_table(pte_dir, TABLE_PTE);
> +               }
>         }
>  #endif
>  }

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

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