[PATCH v6 3/3] iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801

[Shameerali Kolothum Thodi]

Hi Will,

> -----Original Message-----
> From: Will Deacon [mailto:will.deacon at arm.com]
> Sent: Thursday, August 10, 2017 6:27 PM
> To: Shameerali Kolothum Thodi
> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; robin.murphy at arm.com; hanjun.guo at linaro.org;
> Gabriele Paoloni; John Garry; iommu at lists.linux-foundation.org; linux-arm-
> kernel at lists.infradead.org; linux-acpi at vger.kernel.org; devel at acpica.org;
> Linuxarm; Wangzhou (B); Guohanjun (Hanjun Guo)
> Subject: Re: [PATCH v6 3/3] iommu/arm-smmu-v3:Enable ACPI based
> HiSilicon erratum 161010801
> 
> On Wed, Aug 09, 2017 at 11:07:15AM +0100, Shameer Kolothum wrote:
> > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > platforms Hip06/Hip07 to support the SMMU mappings for MSI
> transactions.
> >
> > On these platforms GICv3 ITS translator is presented with the deviceID
> > by extending the MSI payload data to 64 bits to include the deviceID.
> > Hence, the PCIe controller on this platforms has to differentiate the
> > MSI payload against other DMA payload and has to modify the MSI
> payload.
> > This basically makes it difficult for this platforms to have a SMMU
> > translation for MSI.
> >
> > This patch implements a ACPI table based quirk to reserve the hw msi
> > regions in the smmu-v3 driver which means these address regions will
> > not be translated and will be excluded from iova allocations.
> >
> > Signed-off-by: Shameer Kolothum
> <shameerali.kolothum.thodi at huawei.com>
> > ---
> >  drivers/iommu/arm-smmu-v3.c | 27 ++++++++++++++++++++++-----
> >  1 file changed, 22 insertions(+), 5 deletions(-)
> 
> Please can you also add a devicetree binding with corresponding
> documentation to enable this workaround on non-ACPI based systems too?
> It should be straightforward if you update the arm_smmu_options table.

As I mentioned before, devicetree was a lower priority and we would definitely
submit patch to support that. Even if we update the arm_smmu_options table
with DT binding, the generic function to retrieve the MSI address regions only
works on ACPI/IORT case now.

Moreover I am on holidays starting tomorrow, and really appreciate if this series
can go through now.

Please let me know.

Thanks,
Shameer