Subject: Re: Machine-independent bus DMA interface proposal
To: None <tech-kern@NetBSD.ORG>
From: Jason Thorpe <>
List: tech-kern
Date: 09/24/1996 17:52:56
On Tue, 24 Sep 1996 17:04:46 -0700 
 Jonathan Stone <> wrote:

 > To repeat an earlier plea: can we rename  the "bus_dma_load()"
 > and "bus_dma_unload()" operators to be "bus_dma_bind()" and
 > "bus_dma_unbind()", respectively?

Oh, I must have missed this request....

Anyhow, let me first explain the name...

bus_dmamap_create() creates a DMA map... as the name implies...

bus_dmamap_load() does the necessary machine-dependent magic, and
loads the map with the mapping.  I suppose one could call this
"binding a mapping" ... unload unloads the mapping from the map.

I guess I'm not really objecting to changing the names, tho...

 > Last, and most importantly, I thought the purpose of this interface
 > was to provide a bus-independent, machine-independent way to write
 > *bus* mapping registers, not *board*-level mapping registers.  That's
 > a fine distinction which seems to *NOT* be being made, and I think it
 > absolutely needs to be, or we're tlaking past each other.

It has never been my intention to have this interface write
board-level registers.

 > Anyone who thinks it's possible or reasonable to write
 > driver-level "machine-indepedent" code to handle bus-level mapping
 > registers has, IMHO, no place , participating in this discussion.

Jason R. Thorpe                             
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