IB/ehca: Use WQE offset instead of WQE addr for pending work reqs

This is a patch for ehca to fix a bug in prepare_sqe_to_rts(), which
used WQE address to iterate pending work requests.  This might cause
an access violation since the queue pages can not be assumed to follow
each other consecutively.  Thus, this patch introduces a few queue
functions to determine WQE offset based on its address and uses WQE
offset to iterate the pending work requests.

Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ehca/ipz_pt_fn.h b/drivers/infiniband/hw/ehca/ipz_pt_fn.h
index 2f13509d525..dc3bda2634b 100644
--- a/drivers/infiniband/hw/ehca/ipz_pt_fn.h
+++ b/drivers/infiniband/hw/ehca/ipz_pt_fn.h
@@ -150,6 +150,21 @@ static inline void *ipz_qeit_reset(struct ipz_queue *queue)
 	return ipz_qeit_get(queue);
 }
 
+/*
+ * return the q_offset corresponding to an absolute address
+ */
+int ipz_queue_abs_to_offset(struct ipz_queue *queue, u64 addr, u64 *q_offset);
+
+/*
+ * return the next queue offset. don't modify the queue.
+ */
+static inline u64 ipz_queue_advance_offset(struct ipz_queue *queue, u64 offset)
+{
+	offset += queue->qe_size;
+	if (offset >= queue->queue_length) offset = 0;
+	return offset;
+}
+
 /* struct generic page table */
 struct ipz_pt {
 	u64 entries[EHCA_PT_ENTRIES];