[PATCH 5/5] arm: dts: Convert mvebu device tree files to 64 bits

Lior Amsalem alior at marvell.com
Fri Mar 22 08:58:28 EST 2013


> From: Jason Gunthorpe [mailto:jgunthorpe at obsidianresearch.com]
> Sent: Thursday, March 21, 2013 11:46 PM
>
> On Thu, Mar 21, 2013 at 11:35:21PM +0200, Lior Amsalem wrote:
> 
> > >  *) It would require Linux to change the internal registers address
> > >     (for now the kernel relies on the bootloader). The problem is that
> > >     we can't do it early enough to preserve the earlyprintk
> > >     functionality. Maybe you have suggestions on how to achieve that?
> >
> > Please note that all registers and IOs are still 32bit, the 40bit
> > extension is on the CPU to DRAM path (windows) only.
> 
> Ah, I did wonder, since Ezequiel's MBUS driver was the same as on prior
> families. I guess it is also the case that all on board DMA and DMA from PCI-E
> devices are restricted to the low 32 bits as well?

Correct, that's why we sets DMABOUNCE config.

> 
> I think lots of Linux workloads will really struggle under those conditions..
> 
> Jason

Regards,
Lior Amsalem




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