From: Paul Burton <paul.burton@mips.com>
To: Christoph Hellwig <hch@lst.de>
Cc: David Daney <ddaney@caviumnetworks.com>,
Huacai Chen <chenhc@lemote.com>,
linux-mips@linux-mips.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] MIPS: remove mips_swiotlb_ops
Date: Sat, 28 Jul 2018 12:06:18 -0700 [thread overview]
Message-ID: <20180728190618.sq5xbuc2hnthmkhl@pburton-laptop> (raw)
In-Reply-To: <20180727172606.21253-1-hch@lst.de>
Hi Christoph,
On Fri, Jul 27, 2018 at 07:26:06PM +0200, Christoph Hellwig wrote:
> mips_swiotlb_ops differs from the generic swiotlb_dma_ops only in that
> it contains a mb() barrier after each operations that maps or syncs
> dma memory to the device.
>
> The dma operations are defined to not be memory barriers, but instead
> the write* operations to kick the DMA off are supposed to contain them.
>
> For mips this handled by war_io_reorder_wmb(), which evaluates to the
> stronger wmb() instead of the pure compiler barrier barrier() for
> just those platforms that use swiotlb, so I think we are covered
> properly.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> arch/mips/include/asm/dma-mapping.h | 3 +-
> arch/mips/mm/Makefile | 1 -
> arch/mips/mm/dma-swiotlb.c | 61 -----------------------------
> 3 files changed, 1 insertion(+), 64 deletions(-)
> delete mode 100644 arch/mips/mm/dma-swiotlb.c
Thanks - this looks reasonable, but needed a small tweak to gain the
definition of swiotlb_dma_ops from linux/swiotlb.h (as riscv & unicore32
do) in order to avoid build failures.
Hooray for even more deleted code :)
Applied to mips-next for 4.19.
Paul
prev parent reply other threads:[~2018-07-28 19:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-27 17:26 [PATCH] MIPS: remove mips_swiotlb_ops Christoph Hellwig
2018-07-28 19:06 ` Paul Burton [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180728190618.sq5xbuc2hnthmkhl@pburton-laptop \
--to=paul.burton@mips.com \
--cc=chenhc@lemote.com \
--cc=ddaney@caviumnetworks.com \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).