From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bart Hartgers <bart@etpmod.phys.tue.nl>
Cc: "Rafał Bilski" <rafalbilski@interia.pl>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] (Longhaul 1/5) PCI: Protect bus master DMA from Longhaul by rw semaphores
Date: Thu, 29 Jun 2006 16:55:51 +0100 [thread overview]
Message-ID: <1151596551.23785.38.camel@localhost.localdomain> (raw)
In-Reply-To: <44A3EEDC.30006@etpmod.phys.tue.nl>
Ar Iau, 2006-06-29 am 17:16 +0200, ysgrifennodd Bart Hartgers:
> Rafał Bilski wrote:
> > CPU is VIA C3 in EBGA "Nehemiah" core 6.9.8.
> > I'm using flush_cache_all(). Is there anything more powerfull?
> > I'm using MSR_VIA_FCR.
> > I can disable L2 cache (or at least I think so) - this doesn't help.
> > I can't disable L1 cache - processor stops when I'm trying to set
> > I-cache or D-cache disable bit.
If you can flush any cached writes to RAM before you do the changeover
and after you disabled interrupts then it ought to be sufficient to
invalidate the cache just before re-enabling everything.
The reason I make that claim is that you know nobody will be DMAing over
the pages of memory you use for the speed change itself. Might need a
little care with the stack that is all.
Alan
next prev parent reply other threads:[~2006-06-29 15:39 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-28 18:25 [PATCH] (Longhaul 1/5) PCI: Protect bus master DMA from Longhaul by rw semaphores Rafał Bilski
2006-06-29 11:37 ` Alan Cox
2006-06-29 12:03 ` Bart Hartgers
2006-06-29 12:50 ` Rafał Bilski
2006-06-29 14:12 ` Rafał Bilski
2006-06-29 15:01 ` Bart Hartgers
2006-06-29 15:40 ` Rafał Bilski
2006-06-30 10:46 ` Bart Hartgers
2006-06-29 15:16 ` Bart Hartgers
2006-06-29 15:55 ` Alan Cox [this message]
2006-06-29 18:54 ` Rafał Bilski
2006-06-29 15:52 ` Alan Cox
[not found] <fa.lpmuYQxc6OV7Bh11JMM/FzqVWyY@ifi.uio.no>
2006-06-29 23:17 ` Robert Hancock
2006-07-01 18:02 ` Rafał Bilski
-- strict thread matches above, loose matches on Subject: below --
2006-06-28 13:56 Rafał Bilski
2006-06-28 17:34 ` Greg KH
2006-06-28 18:03 ` Alan Cox
2006-06-28 18:00 ` Jeremy Fitzhardinge
2006-06-28 18:10 ` Dave Jones
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