Re: [Devel] [RESEND PATCH v9 3/3] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126

[Robert Richter]

On 27.06.17 20:28:14, Geetha Akula wrote:
> On Tue, Jun 27, 2017 at 7:36 PM, Will Deacon <will.deacon@xxxxxxx> wrote:
> > On Tue, Jun 27, 2017 at 03:56:10PM +0200, Robert Richter wrote:
> >> On 23.06.17 19:04:36, Geetha sowjanya wrote:
> >> > From: Geetha Sowjanya <geethasowjanya.akula@xxxxxxxxxx>
> >> >
> >> > Cavium ThunderX2 SMMU doesn't support MSI and also doesn't have unique irq
> >> > lines for gerror, eventq and cmdq-sync.
> >> >
> >> > New named irq "combined" is set as a errata workaround, which allows to
> >> > share the irq line by register single irq handler for all the interrupts.
> >> >
> >> > Signed-off-by: Geetha sowjanya <gakula@xxxxxxxxxxxxxxxxxx>
> >> > ---
> >> >  Documentation/arm64/silicon-errata.txt             |    1 +
> >> >  .../devicetree/bindings/iommu/arm,smmu-v3.txt      |    6 +
> >> >  drivers/acpi/arm64/iort.c                          |   57 ++++++++---
> >> >  drivers/iommu/arm-smmu-v3.c                        |  100 ++++++++++++++-----
> >> >  4 files changed, 121 insertions(+), 43 deletions(-)
> >>
> >> > +static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
> >> > +{
> >> > +   int ret, irq;
> >> > +   u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN;
> >> > +
> >> > +   /* Disable IRQs first */
> >> > +   ret = arm_smmu_write_reg_sync(smmu, 0, ARM_SMMU_IRQ_CTRL,
> >> > +                                 ARM_SMMU_IRQ_CTRLACK);
> >> > +   if (ret) {
> >> > +           dev_err(smmu->dev, "failed to disable irqs\n");
> >> > +           return ret;
> >> > +   }
> >> > +
> >> > +   irq = smmu->combined_irq;
> >> > +   if (irq) {
> >> > +           /*
> >> > +            * Cavium ThunderX2 implementation doesn't not support unique
> >> > +            * irq lines. Use single irq line for all the SMMUv3 interrupts.
> >> > +            */
> >> > +           ret = devm_request_threaded_irq(smmu->dev, irq,
> >> > +                                   arm_smmu_combined_irq_handler,
> >> > +                                   arm_smmu_combined_irq_thread,
> >> > +                                   IRQF_ONESHOT,
> >>
> >> Without the IRQF_SHARED flag set I see the following on a dual node
> >> system now:
> Node1 SMMU interrupts are programmed wrong in the firmware.
> Node 0 and Node1 SMMU do not share interrupts.
> I have verified the patch on dual node with correct interrupt numbers
> programmed in firmware.

Ah, ok, will update to latest fw.

Thanks,

-Robert