Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230802184849.1019466-1-arnd@kernel.org> <20230802184849.1019466-4-arnd@kernel.org>
 <d737e5a40f7e2009222d98de7696cc78740869e3.camel@physik.fu-berlin.de>
In-Reply-To: <d737e5a40f7e2009222d98de7696cc78740869e3.camel@physik.fu-berlin.de>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Fri, 8 Sep 2023 12:20:02 +0200
Message-ID: <CAMuHMdVf6pBn2O61ynkdk9MDj0WiMt-12ffvpzfgL51Kz4_Jfg@mail.gmail.com>
Subject: Re: [PATCH 4/4] sh: machvec: remove custom ioport_{un,}map()
To:     John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc:     Arnd Bergmann <arnd@kernel.org>, linux-sh@vger.kernel.org,
        Rich Felker <dalias@libc.org>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8BIT
Precedence: bulk

Hi Adrian,

On Fri, Sep 8, 2023 at 12:11 PM John Paul Adrian Glaubitz
<glaubitz@physik.fu-berlin.de> wrote:
> On Wed, 2023-08-02 at 20:48 +0200, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > These functions were only used on the microdev
> > board that is now gone, so remove them to simplify
> > the ioport handling.
> >
> > This could be further simplified to use the generic
> > I/O port accessors now.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> >  void ioport_unmap(void __iomem *addr)
> >  {
> > -     if (sh_mv.mv_ioport_unmap)
> > -             sh_mv.mv_ioport_unmap(addr);
> >  }
> >  EXPORT_SYMBOL(ioport_unmap);
>
> Why aren't you removing the function ioport_unmap(void __iomem *addr) completely
> and just turn it into stub? Is it still referenced somewhere?

Because architectures are supposed to implement it (there is no
__weak default).

An alternative would be to provide a dummy static inline, like
e.g. m68k does:

arch/m68k/include/asm/kmap.h:#define ioport_unmap ioport_unmap
arch/m68k/include/asm/kmap.h:static inline void ioport_unmap(void __iomem *p)
arch/m68k/include/asm/kmap.h-{
arch/m68k/include/asm/kmap.h-}

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