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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 27 Jun 2022 10:26:37 +0200
Message-ID: <CAMuHMdVewn0OYA9oJfStk0-+vCKAUou+4Mvd5H2kmrSks1p5jg@mail.gmail.com>
Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS
To:     Michael Schmitz <schmitzmic@gmail.com>
Cc:     Arnd Bergmann <arnd@kernel.org>, scsi <linux-scsi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Jakub Kicinski <kuba@kernel.org>,
        Christoph Hellwig <hch@infradead.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Linux IOMMU <iommu@lists.linux-foundation.org>,
        Khalid Aziz <khalid@gonehiking.org>,
        "Maciej W . Rozycki" <macro@orcam.me.uk>,
        Matt Wang <wwentao@vmware.com>,
        Miquel van Smoorenburg <mikevs@xs4all.net>,
        Mark Salyzyn <salyzyn@android.com>,
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        alpha <linux-alpha@vger.kernel.org>,
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        Denis Efremov <efremov@linux.com>,
        Michael Ellerman <mpe@ellerman.id.au>
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Hi Michael,

On Sat, Jun 18, 2022 at 3:06 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> Am 18.06.2022 um 00:57 schrieb Arnd Bergmann:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > All architecture-independent users of virt_to_bus() and bus_to_virt()
> > have been fixed to use the dma mapping interfaces or have been
> > removed now.  This means the definitions on most architectures, and the
> > CONFIG_VIRT_TO_BUS symbol are now obsolete and can be removed.
> >
> > The only exceptions to this are a few network and scsi drivers for m68k
> > Amiga and VME machines and ppc32 Macintosh. These drivers work correctly
> > with the old interfaces and are probably not worth changing.
>
> The Amiga SCSI drivers are all old WD33C93 ones, and replacing
> virt_to_bus by virt_to_phys in the dma_setup() function there would
> cause no functional change at all.

FTR, the sgiwd93 driver use dma_map_single().

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