From: paulius.zaleckas@gmail.com (Paulius Zaleckas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: Gemini: Add support for PCI BUS
Date: Mon, 29 Nov 2010 21:57:23 +0200 [thread overview]
Message-ID: <4CF405A3.9030205@gmail.com> (raw)
In-Reply-To: <20101129193246.GB20761@n2100.arm.linux.org.uk>
On 11/29/2010 09:32 PM, Russell King - ARM Linux wrote:
> On Mon, Nov 29, 2010 at 06:05:07PM +0200, Paulius Zaleckas wrote:
>> No he really should NOT use readl/writel. The ONLY difference
>> between readl/writel and __raw_readl/__raw_writel is endianess
>> conversion. __raw_*l is not doing it. Which to use depend only
>> on HW.
>
> Wrong. readl/writel have barriers too to guarantee ordering between
> device accesses and memory accesses. (device accesses are already
> ordered with respect to themselves.) __raw variants do not
> guarantee the relative ordering between memory accesses and device
> accesses.
#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#define __iormb() rmb()
#define __iowmb() wmb()
#else
#define __iormb() do { } while (0)
#define __iowmb() do { } while (0)
#endif
CONFIG_ARM_DMA_MEM_BUFFERABLE is NOT defined in this case.
I don't see any other barriers.
readl does endianess conversion. What to do if you don't need it?
Do it one more time?
next prev parent reply other threads:[~2010-11-29 19:57 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-27 12:24 [PATCH] ARM: Gemini: Add support for PCI BUS Hans Ulli Kroll
2010-11-28 19:56 ` Arnd Bergmann
2010-11-29 12:17 ` Hans Ulli Kroll
2010-11-29 15:02 ` Arnd Bergmann
2010-11-29 16:05 ` Paulius Zaleckas
2010-11-29 16:45 ` Arnd Bergmann
2010-11-29 18:52 ` Paulius Zaleckas
2010-11-29 20:02 ` Arnd Bergmann
2010-11-29 20:19 ` Paulius Zaleckas
2010-11-30 8:15 ` Hans Ulli Kroll
2010-11-30 9:34 ` Paulius Zaleckas
2010-12-01 11:52 ` Hans Ulli Kroll
2010-12-01 13:08 ` Paulius Zaleckas
2010-12-01 15:02 ` Hans Ulli Kroll
2010-12-06 10:51 ` Sergei Shtylyov
2010-12-06 12:18 ` Arnd Bergmann
2010-11-29 19:32 ` Russell King - ARM Linux
2010-11-29 19:57 ` Paulius Zaleckas [this message]
-- strict thread matches above, loose matches on Subject: below --
2010-11-20 14:27 [PATCH] ARM: Gemini: Add support for PCI Bus Hans Ulli Kroll
2010-11-20 19:30 ` Paulius Zaleckas
2010-11-26 11:18 ` Russell King - ARM Linux
2010-11-26 11:57 ` Michał Mirosław
2010-11-27 12:16 ` Hans Ulli Kroll
2010-11-27 13:01 ` Michał Mirosław
2010-11-27 15:39 ` Arnd Bergmann
2010-11-29 8:12 ` Hans Ulli Kroll
2010-11-29 14:22 ` Russell King - ARM Linux
2010-11-29 14:50 ` Hans Ulli Kroll
2010-11-29 15:57 ` Arnd Bergmann
2010-11-30 15:38 ` Hans Ulli Kroll
2010-11-30 16:05 ` Russell King - ARM Linux
2010-11-30 16:19 ` Arnd Bergmann
2010-12-01 15:05 ` Hans Ulli Kroll
2010-11-29 15:50 ` 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=4CF405A3.9030205@gmail.com \
--to=paulius.zaleckas@gmail.com \
--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).