From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] OMAP: iommu flush page table entries from L1 and L2 cache
Date: Thu, 28 Apr 2011 14:40:55 +0100 [thread overview]
Message-ID: <20110428134055.GA19709@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <BANLkTin8gugnVoai6VHC7qMgK4eKRXRtHg@mail.gmail.com>
On Fri, Apr 15, 2011 at 06:26:40AM -0500, Gupta, Ramesh wrote:
> Russell,
>
> On Thu, Apr 14, 2011 at 5:30 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Thu, Apr 14, 2011 at 04:52:48PM -0500, Fernando Guzman Lugo wrote:
> >> From: Ramesh Gupta <grgupta@ti.com>
> >>
> >> This patch is to flush the iommu page table entries from L1 and L2
> >> caches using dma_map_single. This also simplifies the implementation
> >> by removing the functions ?flush_iopgd_range/flush_iopte_range.
> >
> > No. ?This usage is just wrong. ?If you're going to use the DMA API then
> > unmap it, otherwise the DMA API debugging will go awol.
> >
>
> Thank you for the comments, this particular memory is always a write
> from the A9 for MMU programming and
> only read from the slave processor, that is the reason for not calling
> the unmap. I can re-look into the changes to call
> unmap in a proper way as this impacts the DMA API.
> Are there any other ways to perform only flush the memory from L1/L2 caches?
We _could_ invent a new API to deal with this, which is probably going
to be far better in the longer term for page table based iommus. That's
going to need some thought - eg, do we need to pass a struct device
argument for the iommu cache flushing so we know whether we need to flush
or not (eg, if we have cache coherent iommus)...
next prev parent reply other threads:[~2011-04-28 13:40 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-14 21:52 [PATCH] OMAP: iommu flush page table entries from L1 and L2 cache Fernando Guzman Lugo
2011-04-14 22:30 ` Russell King - ARM Linux
2011-04-15 2:24 ` KyongHo Cho
2011-04-15 8:12 ` Russell King - ARM Linux
2011-04-15 11:26 ` Gupta, Ramesh
2011-04-28 13:40 ` Russell King - ARM Linux [this message]
2011-04-28 16:48 ` Gupta, Ramesh
2011-08-11 19:28 ` Gupta, Ramesh
2011-08-11 22:29 ` Russell King - ARM Linux
2011-08-12 16:05 ` Gupta, Ramesh
2011-10-16 18:32 ` C.A, Subramaniam
2012-05-29 15:53 ` Gupta, Ramesh
2011-04-18 7:29 ` Arnd Bergmann
2011-04-18 11:05 ` Tony Lindgren
2011-04-18 11:42 ` Hiroshi DOYU
2011-04-18 13:25 ` Arnd Bergmann
2011-04-18 11:58 ` Arnd Bergmann
2011-04-18 12:55 ` Kyungmin Park
2011-04-18 14:13 ` Arnd Bergmann
2011-04-19 9:11 ` Kyungmin Park
2011-04-19 12:01 ` Arnd Bergmann
2011-04-19 12:35 ` Kyungmin Park
2011-04-19 13:02 ` Russell King - ARM Linux
2011-04-19 13:11 ` Arnd Bergmann
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=20110428134055.GA19709@n2100.arm.linux.org.uk \
--to=linux@arm.linux.org.uk \
--cc=linux-arm-kernel@lists.infradead.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).