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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 28 Feb 2019 12:53:30 +0100
Message-ID: <CAMuHMdU5gn6ftAHNwHNPDoUy_JvcZLcXbkk1hvUmYxtfJRfTTQ@mail.gmail.com>
Subject: Re: [PATCH v3 09/34] m68k: mm: Add p?d_large() definitions
To:     Mike Rapoport <rppt@linux.ibm.com>
Cc:     Steven Price <steven.price@arm.com>, Linux MM <linux-mm@kvack.org>,
        Andy Lutomirski <luto@kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>,
        James Morse <james.morse@arm.com>,
        =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= <jglisse@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will.deacon@arm.com>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Mark Rutland <Mark.Rutland@arm.com>,
        "Liang, Kan" <kan.liang@linux.intel.com>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>
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Hi Mike,

On Thu, Feb 28, 2019 at 12:37 PM Mike Rapoport <rppt@linux.ibm.com> wrote:
> On Wed, Feb 27, 2019 at 08:27:40PM +0100, Geert Uytterhoeven wrote:
> > On Wed, Feb 27, 2019 at 6:07 PM Steven Price <steven.price@arm.com> wrote:
> > > walk_page_range() is going to be allowed to walk page tables other than
> > > those of user space. For this it needs to know when it has reached a
> > > 'leaf' entry in the page tables. This information is provided by the
> > > p?d_large() functions/macros.
> > >
> > > For m68k, we don't support large pages, so add stubs returning 0
> > >
> > > CC: Geert Uytterhoeven <geert@linux-m68k.org>
> > > CC: linux-m68k@lists.linux-m68k.org
> > > Signed-off-by: Steven Price <steven.price@arm.com>
> >
> > Thanks for your patch!
> >
> > >  arch/m68k/include/asm/mcf_pgtable.h      | 2 ++
> > >  arch/m68k/include/asm/motorola_pgtable.h | 2 ++
> > >  arch/m68k/include/asm/pgtable_no.h       | 1 +
> > >  arch/m68k/include/asm/sun3_pgtable.h     | 2 ++
> > >  4 files changed, 7 insertions(+)
> >
> > If the definitions are the same, why not add them to
> > arch/m68k/include/asm/pgtable.h instead?
>
> Maybe I'm missing something, but why the stubs have to be defined in
> arch/*/include/asm/pgtable.h rather than in include/asm-generic/pgtable.h?

That would even make more sense, given most architectures don't
support huge pages.

Gr{oetje,eeting}s,

                        Geert

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