From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Wed, 18 May 2016 16:19:58 +0100 Subject: [PATCH v2] arm64: Allow for different DMA and CPU bus offsets In-Reply-To: <573C7D64.5040206@suse.de> References: <1463576010-115428-1-git-send-email-agraf@suse.de> <20160518132741.GE22378@e104818-lin.cambridge.arm.com> <573C72DD.6010400@suse.de> <20160518142620.GA22354@localhost.localdomain> <573C7D64.5040206@suse.de> Message-ID: <20160518151958.GH22378@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > >>>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? -- Catalin