[PATCH v3 07/14] iommu/ioasid: Add an iterator API for ioasid_set

[Jacob Pan <jacob.pan.linux@gmail.com>]

Users of an ioasid_set may not keep track of all the IOASIDs allocated
under the set. When collective actions are needed for each IOASIDs, it
is useful to iterate over all the IOASIDs within the set. For example,
when the ioasid_set is freed, the user might perform the same cleanup
operation on each IOASID.

This patch adds an API to iterate all the IOASIDs within the set.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/iommu/ioasid.c | 17 +++++++++++++++++
 include/linux/ioasid.h |  9 +++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index cf8c7d34e2de..9628e78b2ab4 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c
@@ -701,6 +701,23 @@ int ioasid_adjust_set(struct ioasid_set *set, int quota)
 EXPORT_SYMBOL_GPL(ioasid_adjust_set);
 
 /**
+ * ioasid_set_for_each_ioasid - Iterate over all the IOASIDs within the set
+ *
+ * Caller must hold a reference of the set and handles its own locking.
+ */
+void ioasid_set_for_each_ioasid(struct ioasid_set *set,
+				void (*fn)(ioasid_t id, void *data),
+				void *data)
+{
+	struct ioasid_data *entry;
+	unsigned long index;
+
+	xa_for_each(&set->xa, index, entry)
+		fn(index, data);
+}
+EXPORT_SYMBOL_GPL(ioasid_set_for_each_ioasid);
+
+/**
  * ioasid_find - Find IOASID data
  * @set: the IOASID set
  * @ioasid: the IOASID to find
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index 0a5e82148eb9..aab58bc26714 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -75,6 +75,9 @@ int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
 void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator);
 int ioasid_attach_data(ioasid_t ioasid, void *data);
 void ioasid_detach_data(ioasid_t ioasid);
+void ioasid_set_for_each_ioasid(struct ioasid_set *sdata,
+				void (*fn)(ioasid_t id, void *data),
+				void *data);
 #else /* !CONFIG_IOASID */
 static inline void ioasid_install_capacity(ioasid_t total)
 {
@@ -131,5 +134,11 @@ static inline int ioasid_attach_data(ioasid_t ioasid, void *data)
 static inline void ioasid_detach_data(ioasid_t ioasid)
 {
 }
+
+static inline void ioasid_set_for_each_ioasid(struct ioasid_set *sdata,
+					      void (*fn)(ioasid_t id, void *data),
+					      void *data)
+{
+}
 #endif /* CONFIG_IOASID */
 #endif /* __LINUX_IOASID_H */
-- 
2.7.4