IB/rdmavt: Add QP iterator API for QPs

There are currently 3 spots in the qib and hfi1 driver that have
knowledge of the internal QP hash list that should only be in
scope to rdmavt QP code.

Add an iterator API for processing all QPs to hide the
nature of the RCU hashlist.

The API consists of:
- rvt_qp_iter_init()
  * For iterating QPs one at a time for seq_file semantics
- rvt_qp_iter_next()
  * For iterating QPs one at a time for seq_file semantics
- rvt_qp_iter()
  * For iterating all QPs

The first two are used for things like seq_file prints.

The last is for code that just needs to iterate all QPs
in the system.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h
index 8fbafb0ce674..dfeb311c30a1 100644
--- a/include/rdma/rdmavt_qp.h
+++ b/include/rdma/rdmavt_qp.h
@@ -673,4 +673,33 @@ void rvt_del_timers_sync(struct rvt_qp *qp);
 void rvt_stop_rc_timers(struct rvt_qp *qp);
 void rvt_add_retry_timer(struct rvt_qp *qp);
 
+/**
+ * struct rvt_qp_iter - the iterator for QPs
+ * @qp - the current QP
+ *
+ * This structure defines the current iterator
+ * state for sequenced access to all QPs relative
+ * to an rvt_dev_info.
+ */
+struct rvt_qp_iter {
+	struct rvt_qp *qp;
+	/* private: backpointer */
+	struct rvt_dev_info *rdi;
+	/* private: callback routine */
+	void (*cb)(struct rvt_qp *qp, u64 v);
+	/* private: for arg to callback routine */
+	u64 v;
+	/* private: number of SMI,GSI QPs for device */
+	int specials;
+	/* private: current iterator index */
+	int n;
+};
+
+struct rvt_qp_iter *rvt_qp_iter_init(struct rvt_dev_info *rdi,
+				     u64 v,
+				     void (*cb)(struct rvt_qp *qp, u64 v));
+int rvt_qp_iter_next(struct rvt_qp_iter *iter);
+void rvt_qp_iter(struct rvt_dev_info *rdi,
+		 u64 v,
+		 void (*cb)(struct rvt_qp *qp, u64 v));
 #endif          /* DEF_RDMAVT_INCQP_H */