Hi Geetha,
On Tue, May 30, 2017 at 05:33:41PM +0530, 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.
>
> This patch addresses the issue by checking if any interrupt sources are
> using same irq number, then they are registered as shared irqs.
>
> Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@xxxxxxxxxx>
> ---
> Documentation/arm64/silicon-errata.txt | 1 +
> drivers/iommu/arm-smmu-v3.c | 29 +++++++++++++++++++++++++----
> 2 files changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
> index 4693a32..42422f6 100644
> --- a/Documentation/arm64/silicon-errata.txt
> +++ b/Documentation/arm64/silicon-errata.txt
> @@ -63,6 +63,7 @@ stable kernels.
> | Cavium | ThunderX Core | #27456 | CAVIUM_ERRATUM_27456 |
> | Cavium | ThunderX SMMUv2 | #27704 | N/A |
> | Cavium | ThunderX2 SMMUv3| #74 | N/A |
> +| Cavium | ThunderX2 SMMUv3| #126 | N/A |
> | | | | |
> | Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 |
> | | | | |
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 4e80205..d2db01f 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2232,6 +2232,25 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
> devm_add_action(dev, arm_smmu_free_msis, dev);
> }
>
> +static int get_irq_flags(struct arm_smmu_device *smmu, int irq)
> +{
> + int match_count = 0;
> +
> + if (irq == smmu->evtq.q.irq)
> + match_count++;
> + if (irq == smmu->cmdq.q.irq)
> + match_count++;
> + if (irq == smmu->gerr_irq)
> + match_count++;
> + if (irq == smmu->priq.q.irq)
> + match_count++;
> +
> + if (match_count > 1)
> + return IRQF_SHARED | IRQF_ONESHOT;
> +
> + return IRQF_ONESHOT;
> +}
I really think this is the wrong way of solving the problem: using
IRQF_SHARED has implications elsewhere in the driver (for example, we must
then pass a unique dev_id otherwise freeing the IRQs won't work properly)
and I don't want to have to worry about these constraints just because of
this broken platform.
Please do what I suggested instead: register a single threaded interrupt
handler that acts as a multiplexer and manually calls the other routines.
Will
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
