Re: [PATCH 09/12] dmaengine: idxd: Remove unnecessary IOMMU_DEV_FEAT_IOPF

[Dave Jiang]

On 2/13/25 11:11 PM, Lu Baolu wrote:
> The IOMMU_DEV_FEAT_IOPF implementation in the iommu driver is just a no-op.
> It will also be removed from the iommu driver in the subsequent patch.
> Remove it to avoid dead code.
> 
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>  drivers/dma/idxd/init.c | 37 ++++++-------------------------------
>  1 file changed, 6 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> index 1e5038cca22c..d44944195807 100644
> --- a/drivers/dma/idxd/init.c
> +++ b/drivers/dma/idxd/init.c
> @@ -626,21 +626,6 @@ static void idxd_disable_system_pasid(struct idxd_device *idxd)
>  	idxd->pasid = IOMMU_PASID_INVALID;
>  }
>  
> -static int idxd_enable_sva(struct pci_dev *pdev)
> -{
> -	int ret;
> -
> -	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
> -	if (ret)
> -		return ret;
> -	return 0;
> -}
> -
> -static void idxd_disable_sva(struct pci_dev *pdev)
> -{
> -	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
> -}
> -
>  static int idxd_probe(struct idxd_device *idxd)
>  {
>  	struct pci_dev *pdev = idxd->pdev;
> @@ -655,17 +640,13 @@ static int idxd_probe(struct idxd_device *idxd)
>  	dev_dbg(dev, "IDXD reset complete\n");
>  
>  	if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
> -		if (idxd_enable_sva(pdev)) {
> -			dev_warn(dev, "Unable to turn on user SVA feature.\n");
> -		} else {
> -			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
> +		set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
>  
> -			rc = idxd_enable_system_pasid(idxd);
> -			if (rc)
> -				dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
> -			else
> -				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
> -		}
> +		rc = idxd_enable_system_pasid(idxd);
> +		if (rc)
> +			dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
> +		else
> +			set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
>  	} else if (!sva) {
>  		dev_warn(dev, "User forced SVA off via module param.\n");
>  	}
> @@ -703,8 +684,6 @@ static int idxd_probe(struct idxd_device *idxd)
>   err:
>  	if (device_pasid_enabled(idxd))
>  		idxd_disable_system_pasid(idxd);
> -	if (device_user_pasid_enabled(idxd))
> -		idxd_disable_sva(pdev);
>  	return rc;
>  }
>  
> @@ -715,8 +694,6 @@ static void idxd_cleanup(struct idxd_device *idxd)
>  	idxd_cleanup_internals(idxd);
>  	if (device_pasid_enabled(idxd))
>  		idxd_disable_system_pasid(idxd);
> -	if (device_user_pasid_enabled(idxd))
> -		idxd_disable_sva(idxd->pdev);
>  }
>  
>  /*
> @@ -1248,8 +1225,6 @@ static void idxd_remove(struct pci_dev *pdev)
>  	free_irq(irq_entry->vector, irq_entry);
>  	pci_free_irq_vectors(pdev);
>  	pci_iounmap(pdev, idxd->reg_base);
> -	if (device_user_pasid_enabled(idxd))
> -		idxd_disable_sva(pdev);
>  	pci_disable_device(pdev);
>  	destroy_workqueue(idxd->wq);
>  	perfmon_pmu_remove(idxd);