[RFC PATCH 06/10] iommu: Add iommu_set_bus API interface
From: Lu Baolu
Date: Sun Jul 22 2018 - 02:12:07 EST
This adds iommu_set_bus API by adding a new set_bus ops in the
iommu_ops structure. A vendor IOMMU driver could either specify
its callback or safely ignore it. This interface could be used
to set the iommu methods used for a particular non-pci bus. One
consumer of this interface could be vfio/mdev bus when the mdev
devices could be exclusively protected by the IOMMU units.
Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/iommu.c | 23 +++++++++++++++++++++++
include/linux/iommu.h | 12 ++++++++++++
2 files changed, 35 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 63b3756..b22b0a7 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1976,3 +1976,26 @@ int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
return 0;
}
EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
+
+int iommu_set_bus(struct bus_type *bus)
+{
+ struct iommu_device *iommu;
+ int ret = -ENODEV;
+
+ spin_lock(&iommu_device_lock);
+ /*
+ * Iterate over iommu list and try setting bus with
+ * each iommu until a successful setting.
+ */
+ list_for_each_entry(iommu, &iommu_device_list, list) {
+ if (iommu->ops->set_bus) {
+ ret = iommu->ops->set_bus(bus, iommu);
+ if (!ret)
+ break;
+ }
+ }
+ spin_unlock(&iommu_device_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_set_bus);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee..2679796 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -48,6 +48,7 @@ struct bus_type;
struct device;
struct iommu_domain;
struct notifier_block;
+struct iommu_device;
/* iommu fault flags */
#define IOMMU_FAULT_READ 0x0
@@ -187,6 +188,7 @@ struct iommu_resv_region {
* @domain_get_windows: Return the number of windows for a domain
* @of_xlate: add OF master IDs to iommu grouping
* @pgsize_bitmap: bitmap of all possible supported page sizes
+ * @set_bus: set iommu ops for a non-pci bus
*/
struct iommu_ops {
bool (*capable)(enum iommu_cap);
@@ -235,6 +237,9 @@ struct iommu_ops {
int (*of_xlate)(struct device *dev, struct of_phandle_args *args);
bool (*is_attach_deferred)(struct iommu_domain *domain, struct device *dev);
+ /* Set iommu ops for a bus */
+ int (*set_bus)(struct bus_type *bus, struct iommu_device *iommu);
+
unsigned long pgsize_bitmap;
};
@@ -412,6 +417,8 @@ void iommu_fwspec_free(struct device *dev);
int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids);
const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode);
+int iommu_set_bus(struct bus_type *bus);
+
#else /* CONFIG_IOMMU_API */
struct iommu_ops {};
@@ -696,6 +703,11 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
return NULL;
}
+static inline int iommu_set_bus(struct bus_type *bus)
+{
+ return -ENODEV;
+}
+
#endif /* CONFIG_IOMMU_API */
#endif /* __LINUX_IOMMU_H */
--
2.7.4