From: Ian Campbell <Ian.Campbell@eu.citrix.com>
To: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mingo@elte.hu" <mingo@elte.hu>,
"jeremy@goop.org" <jeremy@goop.org>,
"tony.luck@intel.com" <tony.luck@intel.com>,
"linux-ia64@vger.kernel.org" <linux-ia64@vger.kernel.org>
Subject: Re: [PATCH 01/11] ia64: introduce arch-specific dma-mapping
Date: Tue, 02 Jun 2009 09:18:19 +0000 [thread overview]
Message-ID: <1243934299.8488.31.camel@zakaz.uk.xensource.com> (raw)
In-Reply-To: <20090602130830A.fujita.tomonori@lab.ntt.co.jp>
On Tue, 2009-06-02 at 00:08 -0400, FUJITA Tomonori wrote:
> dma_map_range is a really confusing name. We have dma_map_single and
> dma_map_sg, they are the DMA mapping API.
> dma_map_range sounds like the DMA mapping API but it isn't.
Yes, it's not such a good name. I wonder what would be better?
Perhaps dma_range_mapped? The return value indicates whether the range
is mapped or not so this makes some sense. It also makes it clearer that
this function is not intended to actually perform the mapping if it does
not exist.
> As I said,
> Xen dom0 needs to implement something like xen_map_sg, xen_map_single,
> etc, which uses some of swiotlb functions internally. Then we don't
> need functions like the above.
xen_map_sg would be literally identical to swiotlb_map_sg in every way
apart from the additional phys<->dma address translations. Similarly for
the other swiotlb interfaces. The phys<->dma address translation is also
required for the PowerPC architecture so duplicating all that code just
for Xen doesn't really solve the problem.
Ian.
next prev parent reply other threads:[~2009-06-02 9:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-01 15:32 [PATCH 00/11] swiotlb: Introduce architecture-specific APIs to replace __weak functions (v2) Ian Campbell
2009-06-01 15:32 ` [PATCH 01/11] ia64: introduce arch-specific dma-mapping interfaces Ian Campbell
2009-06-02 4:08 ` [PATCH 01/11] ia64: introduce arch-specific dma-mapping FUJITA Tomonori
2009-06-02 9:18 ` Ian Campbell [this message]
2009-06-01 15:32 ` [PATCH 06/11] swiotlb: use dma_to_phys and phys_to_dma Ian Campbell
2009-06-01 15:32 ` [PATCH 07/11] swiotlb: use dma_map_range Ian Campbell
2009-07-10 5:55 ` [PATCH 00/11] swiotlb: Introduce architecture-specific APIs to Benjamin Herrenschmidt
2009-07-10 14:02 ` Ian Campbell
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=1243934299.8488.31.camel@zakaz.uk.xensource.com \
--to=ian.campbell@eu.citrix.com \
--cc=fujita.tomonori@lab.ntt.co.jp \
--cc=jeremy@goop.org \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tony.luck@intel.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