Mem-2-Mem DMA - Generalized API

Clifford Wolf clifford at
Wed Jul 4 19:05:54 EST 2007


On Mon, Jun 25, 2007 at 08:01:10PM +0200, Clifford Wolf wrote:
> I've put a 'draft header file' of an api as I would have expected it
> online: [...]

Ok, so here comes the first implementation:
(I also have other projects, so it took a while.. ;-)

This is just for the MPC8349 DMA now, registers are still hardcoded in the
driver instead of beeing taken from the platform files and support for
scatter-gather is still missing and the Kconfig integration isn't checking
if we are building for the mpc8349 (or even ppc) yet. But I think the
direction of the API is pretty clear.

The patch also contains a hackish demo client (dma_demo_client.ko) which is
performing some dma transfers in the 256th MB of physical memory. So it
should only be used on a machine with 256MB of memory bootet with mem=255M
(but changing that should be trivial). The demo client shows well how the
API works and how much overhead the API adds.

Any feedback this time?

 - clifford

$c,++$x%14?" ":"\n";while($p=~s/^((.{$c})+)1/${1}0/){}}$_="lPSFZQ".

More information about the Linuxppc-embedded mailing list