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

Baolu Lu
2023-08-14T06:45:57Z

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@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