Re: [PATCH v3 11/20] iommu/fsl_pamu: Add set_platform_dma callback

From: Jason Gunthorpe
Date: Mon Nov 28 2022 - 09:14:37 EST


On Mon, Nov 28, 2022 at 02:46:39PM +0800, Lu Baolu wrote:
> This IOMMU driver doesn't support default domain. Add the implementation
> of set_platform_dma callback so that the IOMMU core could return the
> DMA control.
>
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---
> drivers/iommu/fsl_pamu_domain.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
> index 4408ac3c49b6..b8c716e7c424 100644
> --- a/drivers/iommu/fsl_pamu_domain.c
> +++ b/drivers/iommu/fsl_pamu_domain.c
> @@ -314,6 +314,14 @@ static void fsl_pamu_detach_device(struct iommu_domain *domain,
> pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
> }
>
> +static void fsl_pamu_set_platform_dma(struct device *dev)
> +{
> + struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
> +
> + if (domain)
> + fsl_pamu_detach_device(domain, dev);
> +}

This is a bit ugly, it would be better to make the previous patch call
set_platform_dma if it is set instead of detach_dev and then these
patches should just rename the driver's fsl_pamu_detach_device to
fsl_pamu_set_platform_dma

Then the last patch just deletes the op and the core code

Jason