[PATCH v6 20/25] iommu/sun50i: Add an IOMMU_IDENTITIY_DOMAIN

[Baolu Lu]

On 2023/8/3 8:08, Jason Gunthorpe wrote:
> Prior to commit 1b932ceddd19 ("iommu: Remove detach_dev callbacks") the
> sun50i_iommu_detach_device() function was being called by
> ops->detach_dev().
> 
> This is an IDENTITY domain so convert sun50i_iommu_detach_device() into
> sun50i_iommu_identity_attach() and a full IDENTITY domain and thus hook it
> back up the same was as the old ops->detach_dev().
> 
> Signed-off-by: Jason Gunthorpe<jgg at nvidia.com>
> ---
>   drivers/iommu/sun50i-iommu.c | 26 +++++++++++++++++++-------
>   1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
> index 74c5cb93e90027..0bf08b120cf105 100644
> --- a/drivers/iommu/sun50i-iommu.c
> +++ b/drivers/iommu/sun50i-iommu.c
> @@ -757,21 +757,32 @@ static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
>   	iommu->domain = NULL;
>   }
>   
> -static void sun50i_iommu_detach_device(struct iommu_domain *domain,
> -				       struct device *dev)
> +static int sun50i_iommu_identity_attach(struct iommu_domain *identity_domain,
> +					struct device *dev)
>   {
> -	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
>   	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
> +	struct sun50i_iommu_domain *sun50i_domain;
>   
>   	dev_dbg(dev, "Detaching from IOMMU domain\n");
>   
> -	if (iommu->domain != domain)
> -		return;
> +	if (iommu->domain == identity_domain)
> +		return 0;
>   
> +	sun50i_domain = to_sun50i_domain(iommu->domain);
>   	if (refcount_dec_and_test(&sun50i_domain->refcnt))
>   		sun50i_iommu_detach_domain(iommu, sun50i_domain);
> +	return 0;
>   }

Does iommu->domain need to be set to identity_domain before returning?

Best regards,
baolu