From: James Bottomley <James.Bottomley@SteelEye.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>,
matthew@wil.cx, SCSI Mailing List <linux-scsi@vger.kernel.org>,
Linux Kernel list <linux-kernel@vger.kernel.org>
Subject: Re: iomapping a big endian area
Date: Mon, 04 Apr 2005 08:59:03 -0500 [thread overview]
Message-ID: <1112623143.5813.5.camel@mulgrave> (raw)
In-Reply-To: <1112601039.26086.49.camel@gaston>
On Mon, 2005-04-04 at 17:50 +1000, Benjamin Herrenschmidt wrote:
> I disagree. The driver will never "know" ...
? the driver has to know. Look at the 53c700 to see exactly how awful
it is. This beast has byte and word registers. When used BE, all the
byte registers alter their position (to both inb and readb).
> I don't think it's sane. You know that your device is BE or LE and use
> the appropriate interface. "native" doesn't make sense to me in this
> context.
Well ... it's like this. Native means "pass through without swapping"
and has an easy implementation on both BE and LE platforms. Logically
io{read,write}{16,32}be would have to do byte swaps on LE platforms.
Being lazy, I'm opposed to doing the work if there's no actual use for
it, so can you provide an example of a BE bus (or device) used on a LE
platform that would actually benefit from this abstraction?
James
next prev parent reply other threads:[~2005-04-04 14:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-04-02 20:52 [PATCH] finally fix 53c700 to use the generic iomem infrastructure James Bottomley
2005-04-03 1:37 ` iomapping a big endian area Matthew Wilcox
2005-04-03 2:38 ` David S. Miller
2005-04-03 3:10 ` Matthew Wilcox
2005-04-03 3:40 ` James Bottomley
2005-04-03 4:08 ` David S. Miller
2005-04-03 4:27 ` James Bottomley
2005-04-04 7:50 ` Benjamin Herrenschmidt
2005-04-04 13:59 ` James Bottomley [this message]
2005-04-04 14:16 ` Christoph Hellwig
2005-04-04 14:25 ` James Bottomley
2005-04-07 23:57 ` Jesse Barnes
2005-04-04 14:22 ` Randy.Dunlap
2005-04-04 23:41 ` Benjamin Herrenschmidt
2005-04-04 23:43 ` Benjamin Herrenschmidt
2005-04-04 7:49 ` Benjamin Herrenschmidt
2005-04-05 7:42 ` Russell King
2005-04-05 14:05 ` James Bottomley
2005-04-05 18:55 ` Russell King
2005-04-05 20:02 ` Maciej W. Rozycki
2005-04-04 21:17 ` James Bottomley
2005-04-05 7:21 ` Christoph Hellwig
2005-04-05 14:05 ` James Bottomley
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