This interface allows removal of IOMMU from a bus if needed.
For example, when the IOMMU driver fails to initialize, it should
unassociate itself from the bus (i.e. removing IOMMU groups and
unregister bus notifier block).
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
drivers/iommu/iommu.c | 22 ++++++++++++++++++++++
include/linux/device.h | 1 +
include/linux/iommu.h | 1 +
3 files changed, 24 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d2aa2320..56691ab 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1165,6 +1165,7 @@ static int iommu_bus_init(struct bus_type *bus, const
struct iommu_ops *ops)
if (err)
goto out_err;
+ bus->iommu_nb = nb;
return 0;
@@ -1179,6 +1180,27 @@ static int iommu_bus_init(struct bus_type *bus, const
struct iommu_ops *ops)
return err;
}
+void bus_unset_iommu(struct bus_type *bus, const struct iommu_ops *ops)
+{
+ struct iommu_callback_data cb = {
+ .ops = ops,
+ };
+
+ if (!bus->iommu_ops)
+ return;
+
+ bus_for_each_dev(bus, NULL, &cb, remove_iommu_group);
+
+ if (bus->iommu_nb) {
+ bus_unregister_notifier(bus, bus->iommu_nb);
+ kfree(bus->iommu_nb);
+ bus->iommu_nb = NULL;
+ }
+
+ bus->iommu_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(bus_unset_iommu);
+
/**
* bus_set_iommu - set iommu-callbacks for the bus
* @bus: bus.
diff --git a/include/linux/device.h b/include/linux/device.h
index 4779569..cac7baf 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -133,6 +133,7 @@ struct bus_type {
const struct dev_pm_ops *pm;
const struct iommu_ops *iommu_ops;
+ struct notifier_block *iommu_nb;
struct subsys_private *p;
struct lock_class_key lock_key;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee..65f998e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -287,6 +287,7 @@ static inline struct iommu_device
*dev_to_iommu_device(struct device *dev)
#define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER 6 /* Post Driver unbind */
extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops);
+extern void bus_unset_iommu(struct bus_type *bus, const struct iommu_ops *ops);
extern bool iommu_present(struct bus_type *bus);
extern bool iommu_capable(struct bus_type *bus, enum iommu_cap cap);
extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
--
2.7.4
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