Hi Vikram,
On 07/12/2022 07:18, Vikram Garhwal wrote:
>
>
> Remove master device from the IOMMU.
Adding some description on the purpose would be beneficial.
>
> Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
> ---
> xen/drivers/passthrough/device_tree.c | 38 +++++++++++++++++++++++++++
> xen/include/xen/iommu.h | 2 ++
> 2 files changed, 40 insertions(+)
>
> diff --git a/xen/drivers/passthrough/device_tree.c
> b/xen/drivers/passthrough/device_tree.c
> index 457df333a0..a8ba0b0d17 100644
> --- a/xen/drivers/passthrough/device_tree.c
> +++ b/xen/drivers/passthrough/device_tree.c
> @@ -126,6 +126,44 @@ int iommu_release_dt_devices(struct domain *d)
> return 0;
> }
>
> +int iommu_remove_dt_device(struct dt_device_node *np)
> +{
> + const struct iommu_ops *ops = iommu_get_ops();
> + struct device *dev = dt_to_dev(np);
> + int rc;
> +
Aren't we missing a check if iommu is enabled?
> + if ( !ops )
> + return -EOPNOTSUPP;
-EINVAL to match the return values returned by other functions?
> +
> + spin_lock(&dtdevs_lock);
> +
> + if ( iommu_dt_device_is_assigned_locked(np) ) {
Incorrect coding style. The closing brace should be placed on the next line.
> + rc = -EBUSY;
> + goto fail;
> + }
> +
> + /*
> + * The driver which supports generic IOMMU DT bindings must have
> + * these callback implemented.
> + */
> + if ( !ops->remove_device ) {
Incorrect coding style. The closing brace should be placed on the next line.
> + rc = -EOPNOTSUPP;
-EINVAL to match the return values returned by other functions?
> + goto fail;
> + }
> +
> + /*
> + * Remove master device from the IOMMU if latter is present and
> available.
> + */
No need for a multi-line comment style.
> + rc = ops->remove_device(0, dev);
> +
> + if ( rc == 0 )
!rc is preffered.
> + iommu_fwspec_free(dev);
> +
> +fail:
> + spin_unlock(&dtdevs_lock);
> + return rc;
> +}
> +
> int iommu_add_dt_device(struct dt_device_node *np)
> {
> const struct iommu_ops *ops = iommu_get_ops();
> diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
> index 4f22fc1bed..1b36c0419d 100644
> --- a/xen/include/xen/iommu.h
> +++ b/xen/include/xen/iommu.h
> @@ -225,6 +225,8 @@ int iommu_release_dt_devices(struct domain *d);
> */
> int iommu_add_dt_device(struct dt_device_node *np);
>
> +int iommu_remove_dt_device(struct dt_device_node *np);
These prototypes look to be placed in order. So your function should be
placed before add function.
> +
> int iommu_do_dt_domctl(struct xen_domctl *, struct domain *,
> XEN_GUEST_HANDLE_PARAM(xen_domctl_t));
>
> --
> 2.17.1
>
>
~Michal
