[PATCH 4.8 53/67] IB/rxe: Clear queue buffer when modifying QP to reset

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yonatan Cohen <yonatanc@xxxxxxxxxxxx>

commit aa75b07b478a774b1432e2df1be5cd8ae834de0f upstream.

RXE resets the send-q only once in rxe_qp_init_req() when
QP is created, but when the QP is reused after QP reset, the send-q
holds previous garbage data.

This garbage data wrongly fails CQEs that otherwise
should have completed successfully.

Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: Yonatan Cohen <yonatanc@xxxxxxxxxxxx>
Reviewed-by: Moni Shoua <monis@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/sw/rxe/rxe_qp.c    |    1 +
 drivers/infiniband/sw/rxe/rxe_queue.c |    9 +++++++++
 drivers/infiniband/sw/rxe/rxe_queue.h |    2 ++
 3 files changed, 12 insertions(+)

--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -522,6 +522,7 @@ static void rxe_qp_reset(struct rxe_qp *
 	if (qp->sq.queue) {
 		__rxe_do_task(&qp->comp.task);
 		__rxe_do_task(&qp->req.task);
+		rxe_queue_reset(qp->sq.queue);
 	}
 
 	/* cleanup attributes */
--- a/drivers/infiniband/sw/rxe/rxe_queue.c
+++ b/drivers/infiniband/sw/rxe/rxe_queue.c
@@ -84,6 +84,15 @@ err1:
 	return -EINVAL;
 }
 
+inline void rxe_queue_reset(struct rxe_queue *q)
+{
+	/* queue is comprised from header and the memory
+	 * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
+	 * reset only the queue itself and not the management header
+	 */
+	memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
+}
+
 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
 				 int *num_elem,
 				 unsigned int elem_size)
--- a/drivers/infiniband/sw/rxe/rxe_queue.h
+++ b/drivers/infiniband/sw/rxe/rxe_queue.h
@@ -84,6 +84,8 @@ int do_mmap_info(struct rxe_dev *rxe,
 		 size_t buf_size,
 		 struct rxe_mmap_info **ip_p);
 
+void rxe_queue_reset(struct rxe_queue *q);
+
 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
 				 int *num_elem,
 				 unsigned int elem_size);