[PATCH 3/3] Cell IOMMU static mapping support

Olof Johansson olof at lixom.net
Sat Jan 26 13:51:17 EST 2008

On Fri, Jan 25, 2008 at 09:45:07PM +1100, Michael Ellerman wrote:
> Citing "release early release often", I'm posting this now as a mega-patch
> to get people looking at it. I'll try to split it up and make it look a
> little prettier before submitting it.
> The intent of this patch is to setup (on certain machines) a "static" IOMMU
> mapping of all of memory, to reduce the overhead of the IOMMU. If anyone has
> a better name than "static" I'm all ears.
> So instead of having an IOMMU window that we use to temporarily map things
> in and out of DMA'able space, at boot we create a 1:1 mapping for all of
> memory. This obviously only works for devices that can do 64-bit DMA.

I don't get it. Why not disable the iommu instead?


More information about the Linuxppc-dev mailing list