[PATCH 16/20] iommu/sun50i: Add an IOMMU_IDENTITIY_DOMAIN

[Robin Murphy]

On 2023-05-01 19:03, Jason Gunthorpe wrote:
> This brings back the ops->detach_dev() code that commit
> 1b932ceddd19 ("iommu: Remove detach_dev callbacks") deleted and turns it
> into an IDENTITY domain.
> 
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>   drivers/iommu/sun50i-iommu.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
> index 74c5cb93e90027..15fd62d360778f 100644
> --- a/drivers/iommu/sun50i-iommu.c
> +++ b/drivers/iommu/sun50i-iommu.c
> @@ -772,6 +772,26 @@ static void sun50i_iommu_detach_device(struct iommu_domain *domain,
>   		sun50i_iommu_detach_domain(iommu, sun50i_domain);
>   }
>   
> +static int sun50i_iommu_identity_attach(struct iommu_domain *identity_domain,
> +					struct device *dev)
> +{
> +	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
> +
> +	if (iommu->domain == identity_domain || !iommu->domain)

I don't think that first condition could ever be true.

Thanks,
Robin.

> +		return 0;
> +	sun50i_iommu_detach_device(iommu->domain, dev);
> +	return 0;
> +}
> +
> +static struct iommu_domain_ops sun50i_iommu_identity_ops = {
> +	.attach_dev = sun50i_iommu_identity_attach,
> +};
> +
> +static struct iommu_domain sun50i_iommu_identity_domain = {
> +	.type = IOMMU_DOMAIN_IDENTITY,
> +	.ops = &sun50i_iommu_identity_ops,
> +};
> +
>   static int sun50i_iommu_attach_device(struct iommu_domain *domain,
>   				      struct device *dev)
>   {
> @@ -827,6 +847,7 @@ static int sun50i_iommu_of_xlate(struct device *dev,
>   }
>   
>   static const struct iommu_ops sun50i_iommu_ops = {
> +	.identity_domain = &sun50i_iommu_identity_domain,
>   	.pgsize_bitmap	= SZ_4K,
>   	.device_group	= sun50i_iommu_device_group,
>   	.domain_alloc	= sun50i_iommu_domain_alloc,