Re: [PATCH v5 2/9] iommu/arm: Add iommu_dt_xlate()

[Julien Grall <julien@xxxxxxx>]

Hi Stewart,

On 04/10/2023 15:55, Stewart Hildebrand wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
>
> Move code for processing DT IOMMU specifier to a separate helper.
> This helper will be re-used for adding PCI devices by the subsequent
> patches as we will need exact the same actions for processing
> DT PCI-IOMMU specifier.
>
> While at it introduce NO_IOMMU to avoid magic "1".
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx>
> ---
> v4->v5:
> * rebase on top of "dynamic node programming using overlay dtbo" series
> * move #define NO_IOMMU 1 to header
> * s/these/this/ inside comment
>
> v3->v4:
> * make dt_phandle_args *iommu_spec const
> * move !ops->add_device check to helper
>
> v2->v3:
> * no change
>
> v1->v2:
> * no change
>
> downstream->v1:
> * trivial rebase
> * s/dt_iommu_xlate/iommu_dt_xlate/
>
> (cherry picked from commit c26bab0415ca303df86aba1d06ef8edc713734d3 from
>   the downstream branch poc/pci-passthrough from
>   https://gitlab.com/xen-project/people/bmarquis/xen-arm-poc.git)
> ---
>   xen/drivers/passthrough/device_tree.c | 48 +++++++++++++++++----------
>   xen/include/xen/iommu.h               |  2 ++
>   2 files changed, 32 insertions(+), 18 deletions(-)
>
> diff --git a/xen/drivers/passthrough/device_tree.c 
> b/xen/drivers/passthrough/device_tree.c
> index 075fb25a3706..159ace9856c9 100644
> --- a/xen/drivers/passthrough/device_tree.c
> +++ b/xen/drivers/passthrough/device_tree.c
> @@ -137,6 +137,30 @@ int iommu_release_dt_devices(struct domain *d)
>       return 0;
>   }
>   
> +static int iommu_dt_xlate(struct device *dev,
> +                          const struct dt_phandle_args *iommu_spec)
> +{
> +    const struct iommu_ops *ops = iommu_get_ops();
NIT: Rather than calling iommu_get_ops(), how about passing the ops as a 
parameter of iommu_dt_xlate()?
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall