1 files changed, 62 insertions, 35 deletions

diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 1384060f175d..200b292be63e 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -58,6 +58,8 @@
 #include "vt.h"
 #include "trace.h"
 
+#define RVT_RWQ_COUNT_THRESHOLD 16
+
 static void rvt_rc_timeout(struct timer_list *t);
 
 /*
@@ -835,7 +837,8 @@ int rvt_alloc_rq(struct rvt_rq *rq, u32 size, int node,
 		rq->kwq->curr_wq = rq->kwq->wq;
 	}
 
-	spin_lock_init(&rq->lock);
+	spin_lock_init(&rq->kwq->p_lock);
+	spin_lock_init(&rq->kwq->c_lock);
 	return 0;
 bail:
 	rvt_free_rq(rq);
@@ -892,6 +895,8 @@ static void rvt_init_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
 	qp->s_tail_ack_queue = 0;
 	qp->s_acked_ack_queue = 0;
 	qp->s_num_rd_atomic = 0;
+	if (qp->r_rq.kwq)
+		qp->r_rq.kwq->count = qp->r_rq.size;
 	qp->r_sge.num_sge = 0;
 	atomic_set(&qp->s_reserved_used, 0);
 }
@@ -1097,7 +1102,6 @@ struct ib_qp *rvt_create_qp(struct ib_pd *ibpd,
 		spin_lock_init(&qp->r_lock);
 		spin_lock_init(&qp->s_hlock);
 		spin_lock_init(&qp->s_lock);
-		spin_lock_init(&qp->r_rq.lock);
 		atomic_set(&qp->refcount, 0);
 		atomic_set(&qp->local_ops_pending, 0);
 		init_waitqueue_head(&qp->wait);
@@ -1305,7 +1309,7 @@ int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err)
 		struct rvt_rwq *wq = NULL;
 		struct rvt_krwq *kwq = NULL;
 
-		spin_lock(&qp->r_rq.lock);
+		spin_lock(&qp->r_rq.kwq->c_lock);
 		/* qp->ip used to validate if there is a  user buffer mmaped */
 		if (qp->ip) {
 			wq = qp->r_rq.wq;
@@ -1331,7 +1335,7 @@ int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err)
 			RDMA_WRITE_UAPI_ATOMIC(wq->tail, tail);
 		else
 			kwq->tail = tail;
-		spin_unlock(&qp->r_rq.lock);
+		spin_unlock(&qp->r_rq.kwq->c_lock);
 	} else if (qp->ibqp.event_handler) {
 		ret = 1;
 	}
@@ -1780,12 +1784,12 @@ int rvt_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
 			return -EINVAL;
 		}
 
-		spin_lock_irqsave(&qp->r_rq.lock, flags);
+		spin_lock_irqsave(&qp->r_rq.kwq->p_lock, flags);
 		next = wq->head + 1;
 		if (next >= qp->r_rq.size)
 			next = 0;
 		if (next == READ_ONCE(wq->tail)) {
-			spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+			spin_unlock_irqrestore(&qp->r_rq.kwq->p_lock, flags);
 			*bad_wr = wr;
 			return -ENOMEM;
 		}
@@ -1810,7 +1814,7 @@ int rvt_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
 			 */
 			smp_store_release(&wq->head, next);
 		}
-		spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+		spin_unlock_irqrestore(&qp->r_rq.kwq->p_lock, flags);
 	}
 	return 0;
 }
@@ -2191,13 +2195,13 @@ int rvt_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
 			return -EINVAL;
 		}
 
-		spin_lock_irqsave(&srq->rq.lock, flags);
+		spin_lock_irqsave(&srq->rq.kwq->p_lock, flags);
 		wq = srq->rq.kwq;
 		next = wq->head + 1;
 		if (next >= srq->rq.size)
 			next = 0;
 		if (next == READ_ONCE(wq->tail)) {
-			spin_unlock_irqrestore(&srq->rq.lock, flags);
+			spin_unlock_irqrestore(&srq->rq.kwq->p_lock, flags);
 			*bad_wr = wr;
 			return -ENOMEM;
 		}
@@ -2209,7 +2213,7 @@ int rvt_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
 			wqe->sg_list[i] = wr->sg_list[i];
 		/* Make sure queue entry is written before the head index. */
 		smp_store_release(&wq->head, next);
-		spin_unlock_irqrestore(&srq->rq.lock, flags);
+		spin_unlock_irqrestore(&srq->rq.kwq->p_lock, flags);
 	}
 	return 0;
 }
@@ -2266,6 +2270,31 @@ bad_lkey:
 }
 
 /**
+ * get_count - count numbers of request work queue entries
+ * in circular buffer
+ * @rq: data structure for request queue entry
+ * @tail: tail indices of the circular buffer
+ * @head: head indices of the circular buffer
+ *
+ * Return - total number of entries in the circular buffer
+ */
+static u32 get_count(struct rvt_rq *rq, u32 tail, u32 head)
+{
+	u32 count;
+
+	count = head;
+
+	if (count >= rq->size)
+		count = 0;
+	if (count < tail)
+		count += rq->size - tail;
+	else
+		count -= tail;
+
+	return count;
+}
+
+/**
  * get_rvt_head - get head indices of the circular buffer
  * @rq: data structure for request queue entry
  * @ip: the QP
@@ -2298,7 +2327,7 @@ int rvt_get_rwqe(struct rvt_qp *qp, bool wr_id_only)
 {
 	unsigned long flags;
 	struct rvt_rq *rq;
-	struct rvt_krwq *kwq;
+	struct rvt_krwq *kwq = NULL;
 	struct rvt_rwq *wq;
 	struct rvt_srq *srq;
 	struct rvt_rwqe *wqe;
@@ -2320,16 +2349,16 @@ int rvt_get_rwqe(struct rvt_qp *qp, bool wr_id_only)
 		ip = qp->ip;
 	}
 
-	spin_lock_irqsave(&rq->lock, flags);
+	spin_lock_irqsave(&rq->kwq->c_lock, flags);
 	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
 		ret = 0;
 		goto unlock;
 	}
+	kwq = rq->kwq;
 	if (ip) {
 		wq = rq->wq;
 		tail = RDMA_READ_UAPI_ATOMIC(wq->tail);
 	} else {
-		kwq = rq->kwq;
 		tail = kwq->tail;
 	}
 
@@ -2337,8 +2366,11 @@ int rvt_get_rwqe(struct rvt_qp *qp, bool wr_id_only)
 	if (tail >= rq->size)
 		tail = 0;
 
-	head = get_rvt_head(rq, ip);
-	if (unlikely(tail == head)) {
+	if (kwq->count < RVT_RWQ_COUNT_THRESHOLD) {
+		head = get_rvt_head(rq, ip);
+		kwq->count = get_count(rq, tail, head);
+	}
+	if (unlikely(kwq->count == 0)) {
 		ret = 0;
 		goto unlock;
 	}
@@ -2362,36 +2394,31 @@ int rvt_get_rwqe(struct rvt_qp *qp, bool wr_id_only)
 	}
 	qp->r_wr_id = wqe->wr_id;
 
+	kwq->count--;
 	ret = 1;
 	set_bit(RVT_R_WRID_VALID, &qp->r_aflags);
 	if (handler) {
-		u32 n;
-
 		/*
 		 * Validate head pointer value and compute
 		 * the number of remaining WQEs.
 		 */
-		n = get_rvt_head(rq, ip);
-		if (n >= rq->size)
-			n = 0;
-		if (n < tail)
-			n += rq->size - tail;
-		else
-			n -= tail;
-		if (n < srq->limit) {
-			struct ib_event ev;
-
-			srq->limit = 0;
-			spin_unlock_irqrestore(&rq->lock, flags);
-			ev.device = qp->ibqp.device;
-			ev.element.srq = qp->ibqp.srq;
-			ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
-			handler(&ev, srq->ibsrq.srq_context);
-			goto bail;
+		if (kwq->count < srq->limit) {
+			kwq->count = get_count(rq, tail, get_rvt_head(rq, ip));
+			if (kwq->count < srq->limit) {
+				struct ib_event ev;
+
+				srq->limit = 0;
+				spin_unlock_irqrestore(&rq->kwq->c_lock, flags);
+				ev.device = qp->ibqp.device;
+				ev.element.srq = qp->ibqp.srq;
+				ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
+				handler(&ev, srq->ibsrq.srq_context);
+				goto bail;
+			}
 		}
 	}
 unlock:
-	spin_unlock_irqrestore(&rq->lock, flags);
+	spin_unlock_irqrestore(&rq->kwq->c_lock, flags);
 bail:
 	return ret;
 }