Re: [patch 33/37] iommu/arm-smmu-v3: Use msi_get_virq()

Will Deacon
2021-11-29T11:48:22Z

Hi Thomas,

On Sat, Nov 27, 2021 at 02:20:59AM +0100, Thomas Gleixner wrote:
> Let the core code fiddle with the MSI descriptor retrieval.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 19 +++----------------
> 1 file changed, 3 insertions(+), 16 deletions(-)
>
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -3154,7 +3154,6 @@ static void arm_smmu_write_msi_msg(struc
>
> static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
> {
> - struct msi_desc *desc;
> int ret, nvec = ARM_SMMU_MAX_MSIS;
> struct device *dev = smmu->dev;
>
> @@ -3182,21 +3181,9 @@ static void arm_smmu_setup_msis(struct a
> return;
> }
>
> - for_each_msi_entry(desc, dev) {
> - switch (desc->msi_index) {
> - case EVTQ_MSI_INDEX:
> - smmu->evtq.q.irq = desc->irq;
> - break;
> - case GERROR_MSI_INDEX:
> - smmu->gerr_irq = desc->irq;
> - break;
> - case PRIQ_MSI_INDEX:
> - smmu->priq.q.irq = desc->irq;
> - break;
> - default: /* Unknown */
> - continue;
> - }
> - }
> + smmu->evtq.q.irq = msi_get_virq(dev, EVTQ_MSI_INDEX);
> + smmu->gerr_irq = msi_get_virq(dev, GERROR_MSI_INDEX);
> + smmu->priq.q.irq = msi_get_virq(dev, PRIQ_MSI_INDEX);

Prviously, if retrieval of the MSI failed then we'd fall back to wired
interrupts. Now, I think we'll clobber the interrupt with 0 instead. Can
we make the assignments to smmu->*irq here conditional on the MSI being
valid, please?

Cheers,

Will