From: Frank Rowand <frank_rowand@mvista•com>
To: Dan Malek <dan@mvista•com>
Cc: Geert Uytterhoeven <geert@linux-m68k•org>,
paulus@linuxcare•com.au,
Linux/PPC Development <linuxppc-dev@lists•linuxppc.org>
Subject: Re: __ioremap_at() in 2.4.0-test9-pre2
Date: Fri, 22 Sep 2000 13:06:01 -0700 [thread overview]
Message-ID: <39CBBBA9.38DB93DF@mvista.com> (raw)
In-Reply-To: 39CBA90A.58092A25@mvista.com
Dan Malek wrote:
>
> Geert Uytterhoeven wrote:
>
> > But you suggested the use of the MMU to map all I/O spaces from all bridges
> > into one merged and consecutive universal I/O space.
>
> Well, Paul is suggesting that, I don't really care and I think it
> is a detail that doesn't matter. I prefer the approach:
>
> addr_to_use = tell_me_where()
> inb(addr_to_use)
>
> but I guess I am wrong on this :-). Everyone seems to like hacking
> addresses either in the PCI resources structures or within the macros
> rather than doing it as a one time operation in some well contained
> platform specific function. I already know I can't use a simple
I've been staying out of this discussion because I didn't want to just add
noise. But what the heck... I think that the flexibility of the
tell_me_where() approach is very appealing. It allows for arbitrary future
designs of hardware topologies, including complex fabrics. (OK, so I don't
know of any planned fabric designs for PowerPC, just other architectures.)
I do know that the IBM 405 processors have split PCI I/O space into two
non-contigous blocks in the physical address map. My current implementation
only allows access to the first block. Adding the second block is going
to be a bit "painful" (extra code complexity, etc) for me.
> mapping/arithmetic solution on a platform I have, so I am going to
> pay a high penalty for people using in/out on PCI I/O space. Fortunately,
> I can use drivers for devices that have PCI memory, although I will
> have to modify them, and most of the drivers will be new and unique.
-Frank
--
Frank Rowand <frank_rowand@mvista•com>
MontaVista Software, Inc
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2000-09-22 20:06 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-09-17 18:59 __ioremap_at() in 2.4.0-test9-pre2 Geert Uytterhoeven
2000-09-19 3:59 ` Paul Mackerras
2000-09-19 5:56 ` Michel Lanners
2000-09-19 14:28 ` Dan Malek
2000-09-19 18:31 ` Roman Zippel
2000-09-19 20:09 ` Dan Malek
2000-09-19 23:42 ` Roman Zippel
2000-09-20 0:10 ` Dan Malek
2000-09-20 17:18 ` Roman Zippel
2000-09-20 18:11 ` Dan Malek
2000-09-20 20:22 ` Roman Zippel
2000-09-20 20:41 ` David Edelsohn
2000-09-21 2:16 ` Dan Malek
2000-09-21 2:26 ` David Edelsohn
2000-09-21 2:40 ` Dan Malek
2000-09-21 3:53 ` David Edelsohn
2000-09-19 22:06 ` Matt Porter
2000-09-19 22:58 ` Paul Mackerras
2000-09-20 6:12 ` Matt Porter
2000-09-20 12:15 ` Geert Uytterhoeven
2000-09-20 23:08 ` Paul Mackerras
2000-09-21 20:12 ` Matt Porter
2000-09-20 8:34 ` Roman Zippel
2000-09-20 22:54 ` Paul Mackerras
2000-09-20 15:56 ` Dan Malek
2000-09-20 23:22 ` Paul Mackerras
2000-09-21 2:13 ` Dan Malek
2000-09-21 2:35 ` Paul Mackerras
2000-09-21 3:57 ` Dan Malek
2000-09-21 5:06 ` Paul Mackerras
2000-09-21 6:51 ` Dan Malek
2000-09-21 14:03 ` Geert Uytterhoeven
2000-09-21 22:40 ` Benjamin Herrenschmidt
2000-09-22 3:53 ` Dan Malek
2000-09-22 11:58 ` Geert Uytterhoeven
2000-09-22 18:46 ` Dan Malek
2000-09-22 20:06 ` Frank Rowand [this message]
2000-09-23 21:38 ` Matt Porter
2000-09-21 20:22 ` Matt Porter
2000-09-22 3:49 ` Paul Mackerras
2000-09-22 4:16 ` Dan Malek
2000-09-23 12:34 ` Geert Uytterhoeven
2000-09-27 10:37 ` Benjamin Herrenschmidt
2000-09-28 9:59 ` Geert Uytterhoeven
2000-09-28 19:19 ` Benjamin Herrenschmidt
2000-09-28 23:33 ` Benjamin Herrenschmidt
2000-09-29 5:08 ` Dan Malek
2000-09-29 11:37 ` Geert Uytterhoeven
2000-09-29 17:12 ` Kostas Gewrgiou
2000-09-29 17:18 ` Benjamin Herrenschmidt
2000-09-29 21:35 ` Michel Lanners
2000-09-30 0:11 ` Matt Porter
2000-09-29 0:22 ` Paul Mackerras
2000-09-29 0:40 ` Benjamin Herrenschmidt
2000-09-29 1:17 ` Paul Mackerras
2000-09-29 4:22 ` Dan Malek
2000-09-29 4:29 ` Dan Malek
2000-09-29 4:36 ` Paul Mackerras
2000-09-29 5:40 ` Dan Malek
2000-09-29 19:07 ` Frank Rowand
2000-09-30 1:39 ` Paul Mackerras
2000-09-30 22:50 ` Frank Rowand
2000-10-01 1:09 ` Dan Malek
2000-10-01 8:16 ` Paul Mackerras
2000-10-01 21:30 ` Dan Malek
2000-10-01 22:50 ` Paul Mackerras
2000-10-02 9:04 ` Dan Malek
2000-09-28 23:24 ` Frank Rowand
2000-09-21 13:44 ` Geert Uytterhoeven
2000-09-21 22:41 ` Benjamin Herrenschmidt
2000-09-22 21:59 ` Michel Lanners
2000-09-20 12:08 ` Geert Uytterhoeven
2000-09-20 16:31 ` Matt Porter
-- strict thread matches above, loose matches on Subject: below --
2000-09-21 7:30 Iain Sandoe
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