From: Christoph Hellwig <hch@infradead.org>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
joro@8bytes.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/dma: Zero pages manually in a length of scatterlist
Date: Mon, 5 Nov 2018 06:58:47 -0800 [thread overview]
Message-ID: <20181105145847.GA31337@infradead.org> (raw)
In-Reply-To: <20181102233613.GA26856@Asurada-Nvidia.nvidia.com>
On Fri, Nov 02, 2018 at 04:36:13PM -0700, Nicolin Chen wrote:
> > What if the pages came from highmem? I know that doesn't happen on arm64
> > today, but the point of this code *is* to be generic, and other users will
> > arrive eventually.
>
> Hmm, so it probably should use sg_miter_start/stop() too? Looking
> at the flush routine doing in PAGE_SIZE for each iteration, would
> be possible to map and memset contiguous pages together? Actually
> the flush routine might be also optimized if we can map contiguous
> pages.
FYI, I have patches I plan to submit soon that gets rid of the
struct scatterlist use in this code to simplify it:
http://git.infradead.org/users/hch/misc.git/commitdiff/84e837fc3248b513f73adde49e04e7c58f605113
next prev parent reply other threads:[~2018-11-05 14:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-01 21:35 [PATCH] iommu/dma: Zero pages manually in a length of scatterlist Nicolin Chen
2018-11-02 16:54 ` Robin Murphy
2018-11-02 23:36 ` Nicolin Chen
2018-11-05 14:58 ` Christoph Hellwig [this message]
2018-11-06 14:39 ` Robin Murphy
2018-11-09 7:45 ` Christoph Hellwig
2018-11-06 18:27 ` Robin Murphy
2018-11-07 0:11 ` Nicolin Chen
2018-11-04 15:50 ` Christoph Hellwig
2018-11-06 23:46 ` Nicolin Chen
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