The device iommu probe/attach might have failed leaving dev->iommu to NULL and device drivers may still invoke these functions resulting in a crash in iommu vendor driver code. Hence make sure we check that.

Also added iommu_ops to the "struct dev_iommu" and set it if the dev is successfully associated with an iommu.

Fixes: a3a195929d40 ("iommu: Add APIs for multiple domains per device") Signed-off-by: Shameer Kolothum shameerali.kolothum.thodi@huawei.com --- v1 --> v2: -Added iommu_ops to struct dev_iommu based on the discussion with Robin. -Rebased against iommu-tree core branch. --- drivers/iommu/iommu.c | 19 +++++++------------ include/linux/iommu.h | 2 ++ 2 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index fd76e2f579fe..6023d0b7c542 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -217,6 +217,7 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list }

dev->iommu->iommu_dev = iommu_dev; + dev->iommu->ops = iommu_dev->ops;

group = iommu_group_get_for_dev(dev); if (IS_ERR(group)) { @@ -2865,10 +2866,8 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); */ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; - - if (ops && ops->dev_enable_feat) - return ops->dev_enable_feat(dev, feat); + if (dev->iommu && dev->iommu->ops->dev_enable_feat) + return dev->iommu->ops->dev_enable_feat(dev, feat);

return -ENODEV; } @@ -2881,10 +2880,8 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; - - if (ops && ops->dev_disable_feat) - return ops->dev_disable_feat(dev, feat); + if (dev->iommu && dev->iommu->ops->dev_disable_feat) + return dev->iommu->ops->dev_disable_feat(dev, feat);

return -EBUSY; } @@ -2892,10 +2889,8 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature);

bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; - - if (ops && ops->dev_feat_enabled) - return ops->dev_feat_enabled(dev, feat); + if (dev->iommu && dev->iommu->ops->dev_feat_enabled) + return dev->iommu->ops->dev_feat_enabled(dev, feat);

return false; } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 524ffc2ff64f..ff0c76bdfb67 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -354,6 +354,7 @@ struct iommu_fault_param { * @fault_param: IOMMU detected device fault reporting data * @fwspec: IOMMU fwspec data * @iommu_dev: IOMMU device this device is linked to + * @ops: iommu-ops for talking to the iommu_dev * @priv: IOMMU Driver private data * * TODO: migrate other per device data pointers under iommu_dev_data, e.g. @@ -364,6 +365,7 @@ struct dev_iommu { struct iommu_fault_param *fault_param; struct iommu_fwspec *fwspec; struct iommu_device *iommu_dev; + const struct iommu_ops *ops; void *priv; };