Re: [RFC] [Patch] calgary iommu: Use the first kernel's tce tables in kdump

[Muli Ben-Yehuda <muli@il.ibm.com>]

On Thu, Jul 17, 2008 at 04:14:14PM -0700, Andrew Morton wrote:
> On Tue, 15 Jul 2008 14:15:27 +0530
> Chandru <chandru@in.ibm.com> wrote:
> 
> > kdump kernel fails to boot with calgary iommu and aacraid driver on a x366 
> > box. The ongoing dma's of aacraid from the first kernel continue to exist 
> > until the driver is loaded in the kdump kernel. Calgary is initialized prior 
> > to aacraid and creation of new tce tables causes wrong dma's to occur. Here 
> > we try to get the tce tables of the first kernel in kdump kernel and use 
> > them. While in the kdump kernel we do not allocate new tce tables but instead 
> > read the base addres register contents of calgary iommu and use the tables 
> > that the registers point to. With these changes the kdump kernel and hence 
> > aacraid now boots normally.
> > 
> > Signed-off-by: Chandru Siddalingappa <chandru@in.ibm.com>
> > ---
> > 
> > patch taken on top of linux-2.6.26 stable. Comments from Muli Ben-Yehuda taken 
> > into consideration. Pls apply it as a stop-gap patch until we can come up 
> > with a more stable patch for this issue. Thanks,
> 
> Is this needed in 2.6.26?

No, it's 2.6.27 material.

Cheers,
Muli