Re: [PATCH edk2-platforms] Silicon/SynQuacer: enable coherent DMA for NETSEC and eMMC

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 28 November 2017 at 14:19, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Tue, Nov 28, 2017 at 01:53:49PM +0000, Ard Biesheuvel wrote:
>> On 28 November 2017 at 13:49, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>> > On Tue, Nov 28, 2017 at 01:37:20PM +0000, Ard Biesheuvel wrote:
>> >> On 28 November 2017 at 13:28, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>> >> > As it turns out, it is surprisingly easy to configure both the NETSEC
>> >> > and eMMC devices as cache coherent for DMA, given that they are both
>> >> > behind the same SMMU which is already configured in passthrough mode.
>> >
>> > Configures in passthrough mode by edk2 or earlier firmware?
>>
>> No, it is the CM3 firmware that configures the various SMMUs on this platform.
>
> Right, could you add that to the above statement please?
> "... already configured in passthrough mode by the CM3 firmware."?
>

OK

>> >> > So update the static SMMU configuration to make memory accesses performed
>> >> > by these devices inner shareable, inner/outer writeback cacheable, which
>> >> > makes them cache coherent with the CPUs.
>> >> >
>> >> > Contributed-under: TianoCore Contribution Agreement 1.1
>> >> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> >> > ---
>> >> >  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc                              |  2 +-
>> >> >  Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi                                     |  2 ++
>> >> >  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Emmc.c                                    |  2 +-
>> >> >  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.c                             | 23 ++++++++++++++++++++
>> >> >  Silicon/Socionext/SynQuacer/Include/Platform/MemoryMap.h                                  |  4 ++++
>> >> >  Silicon/Socionext/SynQuacer/Library/SynQuacerMemoryInitPeiLib/SynQuacerMemoryInitPeiLib.c |  3 +++
>> >> >  6 files changed, 34 insertions(+), 2 deletions(-)
>> >> >
>> >> > diff --git a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
>> >> > index 7245240012bc..dd4a7f9baf69 100644
>> >> > --- a/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
>> >> > +++ b/Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc
>> >> > @@ -597,7 +597,7 @@ [Components.common]
>> >> >    NetworkPkg/HttpBootDxe/HttpBootDxe.inf
>> >> >    Silicon/Socionext/SynQuacer/Drivers/Net/NetsecDxe/NetsecDxe.inf {
>> >> >      <LibraryClasses>
>> >> > -      DmaLib|EmbeddedPkg/Library/NonCoherentDmaLib/NonCoherentDmaLib.inf
>> >> > +      DmaLib|EmbeddedPkg/Library/CoherentDmaLib/CoherentDmaLib.inf
>> >> >    }
>> >> >
>> >> >    #
>> >>
>> >> Note: this hunk ^^^ needs to be applied to DeveloperBox.dsc as well.
>> >
>> > Do I wait for a v2 including that?
>> >
>>
>> Would you like me to?
>
> No, I was just wondering.
> Does the .dtsi change not cause issues for DeveloperBox without it?
>

Yes, it does, hence the need to apply this hunk to DeveloperBox.dsc as well.

>> I added this for Daniel and/or Masami, in case they were intending to
>> test this patch. I'd like to get confirmation from them or others that
>> this works as expected before merging this, so there is no rush.
>
> Right, thanks.
>
> /
>     Leif