current-users: Re: diff betw. bus_space_{read,write} and bus_space_{read,write}

Subject: Re: diff betw. bus_space_{read,write} and bus_space_{read,write}_stream?
To: bouyer@antioche.lip6.fr, Ken Nakata <kenn@synap.ne.jp>
From: Matthias Drochner <drochner@zelux6.zel.kfa-juelich.de>
List: current-users
Date: 08/21/1998 12:03:16

Excerpts from netbsd: 21-Aug-98 Re: diff betw. bus_space_{r.. Ken
Nakata@synap.ne.jp (509*)

> Does this mean the stream ones have to _cancell_ the effect of
> a byte-swapping bridge between host and I/O buses?

Yes - it's quite a hardship...
I'm using PCI-VME bridges for quite a while and this is a point
where I'm stuck. From the implementation point of view it would
be probably the best solution to have a separete mapping (ie separate
tag and/or handle) for stream access. Some bridges allow to configure
swapping per mapping window, so one could avoid the software
swapping.

best regards
Matthias