From: Tim Wright <timw@splhi.com>
To: Matti Aarnio <matti.aarnio@zmailer.org>
Cc: Venkatesh Ramamurthy <Venkateshr@ami.com>,
"'Pavel Machek'" <pavel@suse.cz>,
adefacc@tin.it, linux-kernel@vger.kernel.org
Subject: Re: Confirmation request about new 2.4.x. kernel limits
Date: Tue, 9 Jan 2001 08:27:49 -0800 [thread overview]
Message-ID: <20010109082749.A2971@scutter.internal.splhi.com> (raw)
In-Reply-To: <1355693A51C0D211B55A00105ACCFE64E95137@ATL_MS1> <20010109142156.L25659@mea-ext.zmailer.org>
In-Reply-To: <20010109142156.L25659@mea-ext.zmailer.org>; from matti.aarnio@zmailer.org on Tue, Jan 09, 2001 at 02:21:56PM +0200
On Tue, Jan 09, 2001 at 02:21:56PM +0200, Matti Aarnio wrote:
[...]
>
> For IO on usual systems you have 32 bit address space PCI busmasters,
> so those can access only the lowest 4GB of address space, and to have
> a block of data in upper area, it needs to be "bounced", that is, CPU
> must copy it. Linux 2.4.0 system doesn't support 64-bit PCI addresses
> at 32-bit systems (not at 64-bit Alpha either, I recall.)
> On the other hand, Alpha systems and SPARC systems have IOMMU hardware,
> and we do support that (to some extent), but 32-bit intel world doesn't
> have similar things.
>
Hi Matti,
you are correct in saying that ia32 systems don't have IOMMU hardware, but
it's unfortunate that we don't support 64-bit PCI bus master cards, since
they're inexpensive and fairly common now. For instance, the Qlogic ISP SCSI
cards can do 64-bit addressing, as can many others. Has anybody taken a look
at enabling this ?
Tim
--
Tim Wright - timw@splhi.com or timw@aracnet.com or twright@us.ibm.com
IBM Linux Technology Center, Beaverton, Oregon
"Nobody ever said I was charming, they said "Rimmer, you're a git!"" RD VI
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
next prev parent reply other threads:[~2001-01-09 16:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-01-09 4:11 Confirmation request about new 2.4.x. kernel limits Venkatesh Ramamurthy
2001-01-09 12:21 ` Matti Aarnio
2001-01-09 16:27 ` Tim Wright [this message]
2001-01-09 16:44 ` Andi Kleen
2001-01-09 16:50 ` Tim Wright
2001-01-10 13:16 ` Kurt Garloff
2001-01-09 14:05 ` Stephen C. Tweedie
-- strict thread matches above, loose matches on Subject: below --
2001-01-09 18:00 Venkatesh Ramamurthy
2001-01-09 17:35 Venkatesh Ramamurthy
2001-01-09 17:47 ` Andi Kleen
2001-01-09 15:15 Venkatesh Ramamurthy
2001-01-09 15:51 ` Andi Kleen
2001-01-04 11:50 A.D.F.
2001-01-04 11:23 ` Tigran Aivazian
2001-01-04 11:50 ` Anton Blanchard
2001-01-05 22:46 ` Pavel Machek
2001-01-09 14:03 ` Stephen C. Tweedie
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=20010109082749.A2971@scutter.internal.splhi.com \
--to=timw@splhi.com \
--cc=Venkateshr@ami.com \
--cc=adefacc@tin.it \
--cc=linux-kernel@vger.kernel.org \
--cc=matti.aarnio@zmailer.org \
--cc=pavel@suse.cz \
/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.