2020-10-30 05:07:38

by Lu Baolu

Subject: [PATCH v6 2/5] iommu: Use bus iommu ops for aux related callback

The aux-domain apis were designed for macro driver where the subdevices
are created and used inside a device driver. Use the device's bus iommu
ops instead of that in iommu domain for various callbacks.

Signed-off-by: Lu Baolu <[email protected]>
---
drivers/iommu/iommu.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6bbdd959f9f3..17f2686664db 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2913,10 +2913,11 @@ EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
*/
int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
{
+ const struct iommu_ops *ops = dev->bus->iommu_ops;
int ret = -ENODEV;

- if (domain->ops->aux_attach_dev)
- ret = domain->ops->aux_attach_dev(domain, dev);
+ if (ops && ops->aux_attach_dev)
+ ret = ops->aux_attach_dev(domain, dev);

if (!ret)
trace_attach_device_to_domain(dev);
@@ -2927,8 +2928,10 @@ EXPORT_SYMBOL_GPL(iommu_aux_attach_device);

void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
{
- if (domain->ops->aux_detach_dev) {
- domain->ops->aux_detach_dev(domain, dev);
+ const struct iommu_ops *ops = dev->bus->iommu_ops;
+
+ if (ops && ops->aux_detach_dev) {
+ ops->aux_detach_dev(domain, dev);
trace_detach_device_from_domain(dev);
}
}
@@ -2936,10 +2939,11 @@ EXPORT_SYMBOL_GPL(iommu_aux_detach_device);

int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
{
+ const struct iommu_ops *ops = dev->bus->iommu_ops;
int ret = -ENODEV;

- if (domain->ops->aux_get_pasid)
- ret = domain->ops->aux_get_pasid(domain, dev);
+ if (ops && ops->aux_get_pasid)
+ ret = ops->aux_get_pasid(domain, dev);

return ret;
}
--
2.25.1

2020-10-30 05:57:52

by Tian, Kevin

Subject: RE: [PATCH v6 2/5] iommu: Use bus iommu ops for aux related callback

> From: Lu Baolu <[email protected]>
> Sent: Friday, October 30, 2020 12:58 PM
>
> The aux-domain apis were designed for macro driver where the subdevices
> are created and used inside a device driver. Use the device's bus iommu
> ops instead of that in iommu domain for various callbacks.

IIRC there are only two users on these apis. One is VFIO, and the other
is on the ARM side (not checked in yet). Jean, can you help confirm
whether ARM-side usage still relies on aux apis even with this change?
If no, possibly they can be removed completely?

Thanks
Kevin

>
> Signed-off-by: Lu Baolu <[email protected]>
> ---
> drivers/iommu/iommu.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 6bbdd959f9f3..17f2686664db 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2913,10 +2913,11 @@
> EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
> */
> int iommu_aux_attach_device(struct iommu_domain *domain, struct device
> *dev)
> {
> + const struct iommu_ops *ops = dev->bus->iommu_ops;
> int ret = -ENODEV;
>
> - if (domain->ops->aux_attach_dev)
> - ret = domain->ops->aux_attach_dev(domain, dev);
> + if (ops && ops->aux_attach_dev)
> + ret = ops->aux_attach_dev(domain, dev);
>
> if (!ret)
> trace_attach_device_to_domain(dev);
> @@ -2927,8 +2928,10 @@
> EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
>
> void iommu_aux_detach_device(struct iommu_domain *domain, struct
> device *dev)
> {
> - if (domain->ops->aux_detach_dev) {
> - domain->ops->aux_detach_dev(domain, dev);
> + const struct iommu_ops *ops = dev->bus->iommu_ops;
> +
> + if (ops && ops->aux_detach_dev) {
> + ops->aux_detach_dev(domain, dev);
> trace_detach_device_from_domain(dev);
> }
> }
> @@ -2936,10 +2939,11 @@
> EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
>
> int iommu_aux_get_pasid(struct iommu_domain *domain, struct device
> *dev)
> {
> + const struct iommu_ops *ops = dev->bus->iommu_ops;
> int ret = -ENODEV;
>
> - if (domain->ops->aux_get_pasid)
> - ret = domain->ops->aux_get_pasid(domain, dev);
> + if (ops && ops->aux_get_pasid)
> + ret = ops->aux_get_pasid(domain, dev);
>
> return ret;
> }
> --
> 2.25.1

2020-10-30 10:52:26

by Jean-Philippe Brucker

Subject: Re: [PATCH v6 2/5] iommu: Use bus iommu ops for aux related callback

On Fri, Oct 30, 2020 at 05:55:53AM +0000, Tian, Kevin wrote:
> > From: Lu Baolu <[email protected]>
> > Sent: Friday, October 30, 2020 12:58 PM
> >
> > The aux-domain apis were designed for macro driver where the subdevices
> > are created and used inside a device driver. Use the device's bus iommu
> > ops instead of that in iommu domain for various callbacks.
>
> IIRC there are only two users on these apis. One is VFIO, and the other
> is on the ARM side (not checked in yet). Jean, can you help confirm
> whether ARM-side usage still relies on aux apis even with this change?

No, I have something out of tree but no plan to upstream it anymore, and
the SMMUv2 implementation is out as well:

https://lore.kernel.org/linux-iommu/[email protected]/

> If no, possibly they can be removed completely?

No objection from me. They can be added back later (I still belive adding
PASID to the DMA API would be nice to have once more HW implements it).

Thanks,
Jean