From: Tom Rini <trini@kernel.crashing.org>
To: Oliver Neukum <oliver@neukum.name>
Cc: Roland Dreier <roland@topspin.com>,
"David S. Miller" <davem@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: PCI DMA to small buffers on cache-incoherent arch
Date: Mon, 10 Jun 2002 10:29:09 -0700 [thread overview]
Message-ID: <20020610172909.GE14252@opus.bloom.county> (raw)
In-Reply-To: <52d6v19r9n.fsf@topspin.com> <523cvv9laj.fsf@topspin.com> <20020610170309.GC14252@opus.bloom.county> <200206101922.26985.oliver@neukum.name>
On Mon, Jun 10, 2002 at 07:22:26PM +0200, Oliver Neukum wrote:
>
> > > So is the consensus now that in general drivers should make sure any
> > > buffers passed to pci_map/unmap are aligned to SMP_CACHE_BYTES (and a
> > > multiple of SMP_CACHE_BYTES in size)? In other words if a driver uses
> > > an unaligned buffer it should be fixed unless we can prove (and
> > > document in a comment :) that it won't cause problems on an arch
> > > without cache coherency and with a writeback cache.
> >
> > And how about we don't call it SMP_CACHE_BYTES too? The processors
> > where this matters certainly aren't doing SMP...
>
> Definitely we should call it something different so we can limit it to
> architectures that need it.
No. We should just make it come out to a nop for arches that don't need
it. Otherwise we'll end up with ugly things like:
#ifdef CONFIG_NOT_CACHE_COHERENT
...
#else
...
#endif
All over things like USB...
--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/
next prev parent reply other threads:[~2002-06-10 17:30 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-06-08 20:38 PCI DMA to small buffers on cache-incoherent arch Roland Dreier
2002-06-08 13:58 ` Anton Blanchard
2002-06-09 0:52 ` Roland Dreier
2002-06-08 23:03 ` David S. Miller
2002-06-09 0:40 ` Roland Dreier
2002-06-09 0:53 ` David S. Miller
2002-06-09 1:26 ` Roland Dreier
2002-06-09 5:29 ` David S. Miller
2002-06-09 6:16 ` Roland Dreier
2002-06-10 16:03 ` Roland Dreier
2002-06-11 14:04 ` David Woodhouse
2002-06-09 6:45 ` Oliver Neukum
2002-06-10 4:24 ` David S. Miller
2002-06-10 10:00 ` Oliver Neukum
2002-06-10 10:24 ` David S. Miller
2002-06-09 9:51 ` Paul Mackerras
2002-06-09 10:54 ` Benjamin Herrenschmidt
2002-06-10 4:27 ` David S. Miller
2002-06-10 15:59 ` Roland Dreier
2002-06-10 17:03 ` Tom Rini
2002-06-10 17:22 ` Oliver Neukum
2002-06-10 17:29 ` Tom Rini [this message]
2002-06-10 17:39 ` Oliver Neukum
2002-06-10 19:03 ` Roland Dreier
2002-06-10 19:14 ` Tom Rini
2002-06-10 19:21 ` Roland Dreier
2002-06-10 19:26 ` Tom Rini
2002-06-10 17:57 ` Russell King
2002-06-10 17:28 ` Roland Dreier
2002-06-10 18:07 ` William Jhun
2002-06-10 18:29 ` William Jhun
2002-06-10 18:33 ` Mark Zealey
2002-06-10 18:44 ` Oliver Neukum
2002-06-11 3:10 ` David S. Miller
2002-06-11 4:04 ` Roland Dreier
2002-06-11 4:16 ` Brad Hards
2002-06-11 4:24 ` Roland Dreier
2002-06-11 4:24 ` David S. Miller
2002-06-11 4:21 ` David S. Miller
2002-06-11 4:39 ` Roland Dreier
2002-06-11 4:38 ` David S. Miller
2002-06-11 6:23 ` Oliver Neukum
2002-06-11 6:38 ` David S. Miller
2002-06-11 7:38 ` Oliver Neukum
2002-06-11 7:36 ` David S. Miller
2002-06-11 7:43 ` David S. Miller
2002-06-11 8:07 ` Oliver Neukum
2002-06-11 8:15 ` David S. Miller
2002-06-11 12:06 ` Oliver Neukum
2002-06-11 12:04 ` David S. Miller
2002-06-11 14:23 ` Oliver Neukum
2002-06-14 4:14 ` David S. Miller
2002-06-11 18:26 ` Roland Dreier
2002-06-11 17:29 ` Benjamin Herrenschmidt
2002-06-12 12:02 ` Oliver Neukum
2002-06-11 20:06 ` Benjamin Herrenschmidt
2002-06-12 12:02 ` David S. Miller
2002-06-11 23:00 ` Thunder from the hill
2002-06-11 23:56 ` Roland Dreier
2002-06-12 0:09 ` Thunder from the hill
2002-06-11 15:57 ` William Jhun
2002-06-12 9:06 ` Pavel Machek
2002-06-12 20:16 ` David S. Miller
2002-06-12 11:47 ` David S. Miller
2002-06-12 12:08 ` Oliver Neukum
2002-06-14 4:41 ` David S. Miller
2002-06-12 16:09 ` William Jhun
2002-06-09 1:30 ` Albert D. Cahalan
2002-06-09 5:29 ` David S. Miller
2002-06-09 6:33 ` Albert D. Cahalan
2002-06-09 6:50 ` Oliver Neukum
2002-06-09 6:57 ` Albert D. Cahalan
2002-06-09 7:15 ` Oliver Neukum
2002-06-09 8:48 ` Russell King
2002-06-09 15:42 ` Albert D. Cahalan
2002-06-09 23:26 ` Oliver Neukum
-- strict thread matches above, loose matches on Subject: below --
2002-06-11 5:31 David Brownell
2002-06-11 5:44 ` David S. Miller
2002-06-11 15:12 ` David Brownell
2002-06-11 15:44 ` Oliver Neukum
2002-06-12 3:25 ` David S. Miller
2002-06-11 17:33 ` Benjamin Herrenschmidt
2002-06-12 9:42 ` David S. Miller
2002-06-12 14:14 ` David Brownell
2002-06-12 15:00 ` Benjamin Herrenschmidt
2002-06-12 18:44 ` Roland Dreier
2002-06-12 19:13 ` David Brownell
2002-06-12 19:58 ` Oliver Neukum
2002-06-12 22:51 ` David S. Miller
2002-06-12 23:17 ` Oliver Neukum
2002-06-13 4:57 ` David Brownell
2002-06-12 22:46 ` David S. Miller
2002-06-13 5:13 ` David Brownell
2002-06-13 9:38 ` David S. Miller
2002-06-12 22:50 ` David S. Miller
2002-06-12 6:25 ` David Brownell
2002-06-12 6:24 ` David S. Miller
2002-06-12 7:06 ` David Brownell
2002-06-12 9:22 ` David S. Miller
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