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Date: Mon, 09 Sep 2002 11:42:07 -0700
From: Andrew Morton <akpm@digeo.com>
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To: Jesse Barnes <jbarnes@sgi.com>
CC: "Richard B. Johnson" <root@chaos.analogic.com>,
       Imran Badr <imran.badr@cavium.com>,
       "'David S. Miller'" <davem@redhat.com>, phillips@arcor.de,
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Subject: Re: Calculating kernel logical address ..
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Jesse Barnes wrote:
> 
> On Mon, Sep 09, 2002 at 02:00:35PM -0400, Richard B. Johnson wrote:
> > Well I just read Documentation/DMA-mapping.txt as advised by David
> > and it seems as though it will no longer be possible to do what
> > many programmers have been wanting to do, to wit:
> >
> > (1) In user-code, allocate a buffer.
> > (2) Lock that buffer into memory.
> > (3) Call some driver that DMAs data to/from that buffer.
> 
> It looks drivers/media/video/video-buf.c uses alloc_kiovec() and
> map_user_kiobuf() to do it.

For video-buf.c and for Imran's application, that's just a wrapper
which is used to get at get_user_pages().

It would be best to not use the kiobuf code please - its future is
up in the air.  Just use get_user_pages() directly for now.
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