Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device

From: Stephen Boyd
Date: Wed Jul 12 2017 - 18:55:16 EST


On 07/06, Vivek Gautam wrote:
> @@ -1231,12 +1237,18 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
> static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
> size_t size)
> {
> - struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
> + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> + struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
> + size_t ret;
>
> if (!ops)
> return 0;
>
> - return ops->unmap(ops, iova, size);
> + pm_runtime_get_sync(smmu_domain->smmu->dev);

Can these map/unmap ops be called from an atomic context? I seem
to recall that being a problem before.


> + ret = ops->unmap(ops, iova, size);
> + pm_runtime_put_sync(smmu_domain->smmu->dev);
> +
> + return ret;
> }
>
> static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,

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