[PATCH v3 09/10] iommu: Use dev_iommu_ops() helper

[Lu Baolu]

This converts all the feasible instances of dev->bus->iommu_ops to
dev_iommu_ops() in order to make the operation of obtaining iommu_ops
from a device consistent. The dev_iommu_ops() warns on NULL ops, so
we don't need to keep the confusing ops check.

Suggested-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/iommu.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 245e3d2fb74b..27276421d253 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -323,13 +323,14 @@ int iommu_probe_device(struct device *dev)
 
 void iommu_release_device(struct device *dev)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops;
 
 	if (!dev->iommu)
 		return;
 
 	iommu_device_unlink(dev->iommu->iommu_dev, dev);
 
+	ops = dev_iommu_ops(dev);
 	ops->release_device(dev);
 
 	iommu_group_remove_device(dev);
@@ -1522,7 +1523,7 @@ EXPORT_SYMBOL_GPL(fsl_mc_device_group);
 
 static int iommu_get_def_domain_type(struct device *dev)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
 	if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted)
 		return IOMMU_DOMAIN_DMA;
@@ -1581,7 +1582,7 @@ static int iommu_alloc_default_domain(struct iommu_group *group,
  */
 static struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 	struct iommu_group *group;
 	int ret;
 
@@ -1589,9 +1590,6 @@ static struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 	if (group)
 		return group;
 
-	if (!ops)
-		return ERR_PTR(-EINVAL);
-
 	group = ops->device_group(dev);
 	if (WARN_ON_ONCE(group == NULL))
 		return ERR_PTR(-EINVAL);
@@ -2578,17 +2576,17 @@ EXPORT_SYMBOL_GPL(iommu_set_pgtable_quirks);
 
 void iommu_get_resv_regions(struct device *dev, struct list_head *list)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
-	if (ops && ops->get_resv_regions)
+	if (ops->get_resv_regions)
 		ops->get_resv_regions(dev, list);
 }
 
 void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 {
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
-	if (ops && ops->put_resv_regions)
+	if (ops->put_resv_regions)
 		ops->put_resv_regions(dev, list);
 }
 
@@ -2793,9 +2791,9 @@ iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
 {
 	struct iommu_group *group;
 	struct iommu_sva *handle = ERR_PTR(-EINVAL);
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
-	if (!ops || !ops->sva_bind)
+	if (!ops->sva_bind)
 		return ERR_PTR(-ENODEV);
 
 	group = iommu_group_get(dev);
@@ -2836,9 +2834,9 @@ void iommu_sva_unbind_device(struct iommu_sva *handle)
 {
 	struct iommu_group *group;
 	struct device *dev = handle->dev;
-	const struct iommu_ops *ops = dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 
-	if (!ops || !ops->sva_unbind)
+	if (!ops->sva_unbind)
 		return;
 
 	group = iommu_group_get(dev);
@@ -2855,9 +2853,9 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
 
 u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 {
-	const struct iommu_ops *ops = handle->dev->bus->iommu_ops;
+	const struct iommu_ops *ops = dev_iommu_ops(handle->dev);
 
-	if (!ops || !ops->sva_get_pasid)
+	if (!ops->sva_get_pasid)
 		return IOMMU_PASID_INVALID;
 
 	return ops->sva_get_pasid(handle);
-- 
2.25.1