[PATCH v2] arm64: Allow for different DMA and CPU bus offsets

Catalin Marinas catalin.marinas at arm.com
Wed May 18 08:19:58 PDT 2016

On Wed, May 18, 2016 at 04:34:12PM +0200, Alexander Graf wrote:
> On 05/18/2016 04:26 PM, Catalin Marinas wrote:
> >On Wed, May 18, 2016 at 03:49:17PM +0200, Alexander Graf wrote:
> >>On 05/18/2016 03:27 PM, Catalin Marinas wrote:
> >>>On Wed, May 18, 2016 at 02:53:30PM +0200, Alexander Graf wrote:
> >>>>On arm64, all SoCs we supported so far either have an IOMMU or have bus
> >>>>addresses equal to CPU addresses.
> >>>>
> >>>>However, with the Raspberry Pi 3 coming up, this is no longer true. To
> >>>>allow DMA to work with an AArch64 kernel on those devices, let's allow
> >>>>devices to have DMA offsets again.
> >>>>
> >>>>Signed-off-by: Alexander Graf <agraf at suse.de>
> >>>We were aware about this issue but we've been waiting for an actual use
> >>>case. I'll queue this for 4.8 (given that RPi3 is not supported by the
> >>>arm64 kernel, I don't see the rush to merge it earlier).
> >>Sure, works for me. That way Eric can try to push the other few bits
> >>necessary to run an arm64 kernel on the RPi3 towards 4.8 as well :).
> >As long as the firmware is PSCI capable ;)
> So spin tables won't work for you?

They only work for booting, not cpuidle or hotplug.

> IIRC we don't own EL3 on there.

Then how do you switch to AArch64?


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