From: Timur Tabi <timur@freescale.com>
To: Scott Wood <scottwood@freescale.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/5] [POWERPC] QE: add support for QE USB clocks routing
Date: Thu, 17 Apr 2008 15:17:38 -0500 [thread overview]
Message-ID: <4807B062.3080004@freescale.com> (raw)
In-Reply-To: <4807AF9F.4060603@freescale.com>
Scott Wood wrote:
> That's implementation dependent, and support for accesses to uncached
> memory is being phased out of book E according to the E500 manual.
What's wrong with uncached memory?
>> The reservation is held within the processor, so it should work on I/O.
>
> Even if the core supports lwarx/stwcx to uncached memory, the I/O bus
> must support atomic read-modify-write transactions for this to work.
Why? I thought the way that lwarx/stwcx work is that since the processor
detects the reservation collision, and the processor is one doing the writes,
that it would know when the reservation collided. Why does the I/O bus need to
know anything?
> Why do you think you need lwarx/stwcx to I/O?
I figured that if I could use lwarx/stwcx to make clrsetbits atomic, there would
be no need to spinlocks protecting an individual register.
--
Timur Tabi
Linux kernel developer at Freescale
next prev parent reply other threads:[~2008-04-17 20:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-17 19:26 [PATCH 0/5] Few more patches for Kumar's powerpc.git Anton Vorontsov
2008-04-17 19:28 ` [PATCH 1/5] [POWERPC] sysdev: implement FSL GTM support Anton Vorontsov
2008-04-17 22:47 ` Anton Vorontsov
2008-04-18 4:19 ` Kumar Gala
2008-04-18 9:54 ` Anton Vorontsov
2008-04-17 19:28 ` [PATCH 2/5] [POWERPC] QE: add support for QE USB clocks routing Anton Vorontsov
2008-04-17 19:56 ` Timur Tabi
2008-04-17 19:59 ` Scott Wood
2008-04-17 20:04 ` Timur Tabi
2008-04-17 20:14 ` Scott Wood
2008-04-17 20:17 ` Timur Tabi [this message]
2008-04-17 20:26 ` Scott Wood
2008-04-17 20:47 ` Dale Farnsworth
2008-04-17 20:49 ` Timur Tabi
2008-04-17 20:54 ` Dale Farnsworth
2008-04-17 21:48 ` Anton Vorontsov
2008-04-17 22:00 ` Timur Tabi
2008-04-17 19:28 ` [PATCH 3/5] [POWERPC] QE: split par_io_config_pin() Anton Vorontsov
2008-04-17 21:53 ` Kumar Gala
2008-04-17 22:35 ` Anton Vorontsov
2008-04-17 19:29 ` [PATCH 4/5] [POWERPC] QE: implement support for the GPIO LIB API Anton Vorontsov
2008-04-17 22:35 ` Kumar Gala
2008-04-17 22:41 ` Anton Vorontsov
2008-04-18 2:21 ` Kumar Gala
2008-04-17 19:29 ` [PATCH 5/5] [POWERPC] 83xx: new board support: MPC8360E-RDK Anton Vorontsov
-- strict thread matches above, loose matches on Subject: below --
2008-04-18 19:06 [PATCH 0/5 v2] Few more patches for Kumar's powerpc.git Anton Vorontsov
2008-04-18 19:09 ` [PATCH 2/5] [POWERPC] QE: add support for QE USB clocks routing Anton Vorontsov
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=4807B062.3080004@freescale.com \
--to=timur@freescale.com \
--cc=linuxppc-dev@ozlabs.org \
--cc=scottwood@freescale.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.