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From: geert@linux-m68k.org (Geert Uytterhoeven)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS
Date: Thu, 4 May 2017 16:08:29 +0200	[thread overview]
Message-ID: <CAMuHMdXGutH1w8_yV3oToCXoOt3phWE5-b_Sovd8aAP7jC8MPQ@mail.gmail.com> (raw)
In-Reply-To: <20170504140306.GB25108@e104818-lin.cambridge.arm.com>

Hi Catalin,

On Thu, May 4, 2017 at 4:03 PM, Catalin Marinas <catalin.marinas@arm.com> wrote:
> Going through the past threads on this, I wonder whether the attribute
> is actually used anywhere (in which case we may be better off reverting
> the original patch). If improved IOMMU performance is required, there

AFAIK, the users are somewhere in the pipeline.

> are likely better ways to achieve this like using a different page size
> at the IOMMU level.

If I'm not mistaken, it's intended to be used when one device cannot use
the IOMMU for whatever reason.

Gr{oetje,eeting}s,

                        Geert

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

  reply	other threads:[~2017-05-04 14:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20170425180040epcas4p3d96f58d43c973feefbb31e97b9fb2ace@epcas4p3.samsung.com>
2017-04-25 18:00 ` [PATCH] arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS Catalin Marinas
2017-05-04 11:29   ` Robin Murphy
2017-05-04 14:03     ` Catalin Marinas
2017-05-04 14:08       ` Geert Uytterhoeven [this message]
2017-05-04 17:58         ` Catalin Marinas
2017-05-05 10:01   ` Andrzej Hajda

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