mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Jeff Garzik <jgarzik@mandrakesoft.com>
Cc: <linuxppc-dev@lists.linuxppc.org>, <linux-kernel@vger.kernel.org>
Subject: Re: The IO problem on multiple PCI busses
Date: Sat, 3 Mar 2001 18:28:08 +0100	[thread overview]
Message-ID: <19350126105952.7554@smtp.wanadoo.fr> (raw)
In-Reply-To: <3AA0CF0D.CB9D544C@mandrakesoft.com>
In-Reply-To: <3AA0CF0D.CB9D544C@mandrakesoft.com>

>I/O is not supposed to be fast, that's what MMIO is for. :)  Just do
>
>void outb (u8 val, u16 addr)
>{
>	void *addr = ioremap (ISA_IO_BASE + addr);
>	if (addr) {
>		writeb (val, addr);
>		iounmap (addr);
>	}
>}
>
>You can map and unmap for each call :)  Ugly and slow, but hey, it's
>I/O...

Well, that would really suck ;) And I don't think it would be necessary
as we can probably limit each IO bus to 64k without much problem, and
have them permanently ioremap'ed.

Ben.

  reply	other threads:[~2001-03-03 17:29 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-03-01 15:33 Benjamin Herrenschmidt
2001-03-01 15:41 ` Benjamin Herrenschmidt
2001-03-01 18:30 ` Alan Cox
2001-03-01 19:09 ` David S. Miller
2001-03-01 19:33   ` Dan Malek
2001-03-01 19:41   ` David S. Miller
2001-03-01 19:59     ` Dan Malek
2001-03-01 20:09     ` Benjamin Herrenschmidt
2001-03-01 20:22     ` David S. Miller
2001-03-01 20:27     ` David S. Miller
2001-03-02 11:25       ` Benjamin Herrenschmidt
2001-03-03  1:08       ` David S. Miller
2001-03-01 19:49   ` Benjamin Herrenschmidt
2001-03-01 20:21   ` David S. Miller
2001-03-01 22:26     ` Alan Cox
2001-03-02 11:20     ` Benjamin Herrenschmidt
2001-03-03  1:06     ` David S. Miller
2001-03-03  2:25       ` Benjamin Herrenschmidt
2001-03-03 11:01         ` Jeff Garzik
2001-03-03 17:28           ` Benjamin Herrenschmidt [this message]
2001-03-05 16:20         ` David Woodhouse
2001-03-06 23:01       ` Oliver Xymoron
2001-03-07  2:07       ` Tony Mantler
2001-03-05 23:21   ` Chris Wedgwood
2001-03-02  1:22 Grant Grundler
2001-03-02  2:19 ` David S. Miller
2001-03-02 17:46   ` Grant Grundler

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=19350126105952.7554@smtp.wanadoo.fr \
    --to=benh@kernel.crashing.org \
    --cc=jgarzik@mandrakesoft.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.linuxppc.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®