IB/ehca: Refactor "maybe missed event" code

Refactor the ehca changes from commit ed23a727 ("IB: Return "maybe
missed event" hint from ib_req_notify_cq()") so the queue arithmetic
is done in slightly fewer lines. Also, move the spinlock flags into
the block they're used in.

Signed-off-by: Joachim Fenkes <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/hw/ehca/ehca_reqs.c

···
 int ehca_req_notify_cq(struct ib_cq *cq, enum ib_cq_notify_flags notify_flags)
 {
 	struct ehca_cq *my_cq = container_of(cq, struct ehca_cq, ib_cq);
-	unsigned long spl_flags;
 	int ret = 0;
 
 	switch (notify_flags & IB_CQ_SOLICITED_MASK) {
···
 	}
 
 	if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
+		unsigned long spl_flags;
 		spin_lock_irqsave(&my_cq->spinlock, spl_flags);
 		ret = ipz_qeit_is_valid(&my_cq->ipz_queue);
 		spin_unlock_irqrestore(&my_cq->spinlock, spl_flags);

drivers/infiniband/hw/ehca/ipz_pt_fn.h

···
  * step in struct ipz_queue, will wrap in ringbuffer
  * returns address (kv) of Queue Entry BEFORE increment
  * warning don't use in parallel with ipz_qpageit_get_inc()
- * warning unpredictable results may occur if steps>act_nr_of_queue_entries
  */
 static inline void *ipz_qeit_get_inc(struct ipz_queue *queue)
 {
···
 }
 
 /*
+ * return a bool indicating whether current Queue Entry is valid
+ */
+static inline int ipz_qeit_is_valid(struct ipz_queue *queue)
+{
+	struct ehca_cqe *cqe = ipz_qeit_get(queue);
+	return ((cqe->cqe_flags >> 7) == (queue->toggle_state & 1));
+}
+
+/*
  * return current Queue Entry, increment Queue Entry iterator by one
  * step in struct ipz_queue, will wrap in ringbuffer
  * returns address (kv) of Queue Entry BEFORE increment
  * returns 0 and does not increment, if wrong valid state
  * warning don't use in parallel with ipz_qpageit_get_inc()
- * warning unpredictable results may occur if steps>act_nr_of_queue_entries
  */
 static inline void *ipz_qeit_get_inc_valid(struct ipz_queue *queue)
 {
-	struct ehca_cqe *cqe = ipz_qeit_get(queue);
-	u32 cqe_flags = cqe->cqe_flags;
-
-	if ((cqe_flags >> 7) != (queue->toggle_state & 1))
-		return NULL;
-
-	ipz_qeit_get_inc(queue);
-	return cqe;
-}
-
-static inline int ipz_qeit_is_valid(struct ipz_queue *queue)
-{
-	struct ehca_cqe *cqe = ipz_qeit_get(queue);
-	u32 cqe_flags = cqe->cqe_flags;
-
-	return cqe_flags >> 7 == (queue->toggle_state & 1);
+	return ipz_qeit_is_valid(queue) ? ipz_qeit_get_inc(queue) : NULL;
 }
 
 /*