Another thing- maybe I'm confused- but I still don't see why you want to
require the creating of a map each time you want to load an mbuf
chain. Wouldn't it be better and more efficient to let the driver decide when
and where the map is created and just use the common code for loads/unloads?
On Mon, 20 Aug 2001, Matthew Jacob wrote:
>
> Yay!
>
> The current suggestion is fine except that each platform might have a more
> efficient, or even required, actual h/w mechanism for mapping mbufs.
>
> I'd also be a little concerned with the way you're overloading stuff into mbuf
> itself- but I'm a little shakier on this.
>
> Finally- why not make this an inline?
>
> -matt
>
>
> On Mon, 20 Aug 2001, Bill Paul wrote:
>
> > Okay, I decided today to write a bus_dmamap_load_mbuf() routine to
> > make it a little easier to convert the PCI NIC drivers to use the
> > busdma API. It's not the same as the NetBSD code. There are four
> > new functions:
> >
> > bus_dmamap_load_mbuf()
> > bus_dmamap_unload_mbuf()
> > bus_dmamap_sync_mbuf()
> > bus_dmamap_destroy_mbuf()
> >
> > This is more or less in keeping with the existing API, except the new
> > routines work exclusively on mbuf lists. The thing I need to figure
> > out now is where to put the code. The current suggestion from jhb is
> > to create the following two new files:
> >
> > sys/kern/kern_busdma.c
> > sys/sys/busdma.h
> >
> > The functions are machine-independent, so they shouldn't be in
> > sys/<arch>/<arch>/busdma_machdep.c. I mean, they could go there, but
> > that would just result in code duplication. If somebody has a better
> > suggestion, now's the time to speak up. Please let's avoid creating
> > another bikeshed over this.
> >
> > Current code snapshot resides at:
> >
> > http://www.freebsd.org/~wpaul/busdma
> >
> > There's also a modified version if the Adaptec "starfire" driver there
> > which uses the new routines. I'm running this version of the driver on
> > a test box in the lab right now.
> >
> > -Bill
> >
> > --
> > =============================================================================
> > -Bill Paul (510) 749-2329 | Senior Engineer, Master of Unix-Fu
> > [EMAIL PROTECTED] | Wind River Systems
> > =============================================================================
> > "I like zees guys. Zey are fonny guys. Just keel one of zem." -- The 3 Amigos
> > =============================================================================
> >
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> >
>
>
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