Subject: Re: ahc and Semantics of the "COMPLETE" return code
To: None <>
From: Jason Thorpe <>
List: tech-kern
Date: 06/23/1997 22:45:33
On Tue, 24 Jun 1997 00:41:13 -0500 (EST) 
 "John S. Dyson" <> wrote:

 > > >Pluto made a few changes to physio to allow a user process to specify a
 > > >physical address to a chunck of device memory and the I/O we do can
 > > >also be quite large, but it's always to a contiguous piece of memory, so
 > > >the S/G list length doesn't affect us.
 > > >
 > > 
 > > Ah- that's nice- it'd be nice if a {read,write}{v} would just do the
 > > right thing, though.

I suppose I should mention this, considering that I went to all the
trouble to spec it out... :-)

My bus_dma(9) framework already has all the hooks in place for doing
DMA directly to/from userspace.  There's even a call that loads a
dmamap with a uio structure (although the meat of those functions
isn't implemented yet).

Jason R. Thorpe                             
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939