From: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
To: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: benh@kernel.crashing.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org, dwalker@codeaurora.org,
arnd@arndb.de, akpm@linux-foundation.org, mingo@elte.hu,
joerg.roedel@amd.com, maciej.sosnowski@intel.com,
dan.j.williams@intel.com, beckyb@kernel.crashing.org,
yanghy@cn.fujitsu.com, linux-arch@vger.kernel.org,
adharmap@quicinc.com
Subject: Re: [RFC PATCH] dma: Add barrierless dma mapping/unmapping api
Date: Tue, 26 Jan 2010 12:11:34 -0800 [thread overview]
Message-ID: <4B5F4C76.4050100@codeaurora.org> (raw)
In-Reply-To: <20100126134207T.fujita.tomonori@lab.ntt.co.jp>
FUJITA Tomonori wrote:
> On Tue, 26 Jan 2010 15:30:10 +1100
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
>
>> On Mon, 2010-01-25 at 18:35 -0800, adharmap@codeaurora.org wrote:
>>> From: Abhijeet Dharmapurikar <adharmap@quicinc.com>
>>>
>
>> There are people nowadays putting AXI bridges and the whole ARM
>> paraphernalia of IP cores behind them on PowerPC cores for example and I
>> can see that happening with x86 as well.
>>
>> In your case, I believe your are fixing the wrong problem anyways. The
>> right approach would be instead to put all your buffer into an sglist
>> and use dma_map/unmap_sg().
>
> Agreed again. That's exactly what I suggested before:
>
> http://marc.info/?l=linux-kernel&m=126294076917753&w=2
I somehow missed your post, my apologies. Agreed that dma_map/unmap_sg
would be the correct api to use here, however they still call the
dmac_.*_range to map buffers. I could change those calls to do a barrier
only after mapping the last buffer. This would be much more cleaner
than introducing a .*_nobarrier API.
Thanks for all the replies.
next prev parent reply other threads:[~2010-01-26 20:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-26 2:35 [RFC PATCH] dma: Add barrierless dma mapping/unmapping api adharmap
2010-01-26 4:30 ` Benjamin Herrenschmidt
2010-01-26 4:43 ` FUJITA Tomonori
2010-01-26 20:11 ` Abhijeet Dharmapurikar [this message]
2010-01-27 5:19 ` FUJITA Tomonori
2010-01-27 6:49 ` Benjamin Herrenschmidt
2010-01-26 16:48 ` Randy Dunlap
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=4B5F4C76.4050100@codeaurora.org \
--to=adharmap@codeaurora.org \
--cc=adharmap@quicinc.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=beckyb@kernel.crashing.org \
--cc=benh@kernel.crashing.org \
--cc=dan.j.williams@intel.com \
--cc=dwalker@codeaurora.org \
--cc=fujita.tomonori@lab.ntt.co.jp \
--cc=joerg.roedel@amd.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maciej.sosnowski@intel.com \
--cc=mingo@elte.hu \
--cc=yanghy@cn.fujitsu.com \
/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).