RDMA/rxe: Add memory barriers to kernel queues

Earlier patches added memory barriers to protect user space to kernel
space communications. The user space queues were previously shown to have
occasional memory synchonization errors which were removed by adding
smp_load_acquire, smp_store_release barriers.  This patch extends that to
the case where queues are used between kernel space threads.

This patch also extends the queue types to include kernel ULP queues which
access the other end of the queues in kernel verbs calls like poll_cq and
post_send/recv.

Link: https://lore.kernel.org/r/20210914164206.19768-2-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 10 insertions, 43 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 586ef102986e..571cbbeed5d6 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -215,11 +215,7 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	int num_sge = ibwr->num_sge;
 	int full;
 
-	if (rq->is_user)
-		full = queue_full(rq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		full = queue_full(rq->queue, QUEUE_TYPE_KERNEL);
-
+	full = queue_full(rq->queue, QUEUE_TYPE_TO_DRIVER);
 	if (unlikely(full)) {
 		err = -ENOMEM;
 		goto err1;
@@ -234,11 +230,7 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	for (i = 0; i < num_sge; i++)
 		length += ibwr->sg_list[i].length;
 
-	if (rq->is_user)
-		recv_wqe = producer_addr(rq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		recv_wqe = producer_addr(rq->queue, QUEUE_TYPE_KERNEL);
-
+	recv_wqe = queue_producer_addr(rq->queue, QUEUE_TYPE_TO_DRIVER);
 	recv_wqe->wr_id = ibwr->wr_id;
 	recv_wqe->num_sge = num_sge;
 
@@ -251,10 +243,7 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	recv_wqe->dma.cur_sge		= 0;
 	recv_wqe->dma.sge_offset	= 0;
 
-	if (rq->is_user)
-		advance_producer(rq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		advance_producer(rq->queue, QUEUE_TYPE_KERNEL);
+	queue_advance_producer(rq->queue, QUEUE_TYPE_TO_DRIVER);
 
 	return 0;
 
@@ -630,27 +619,17 @@ static int post_one_send(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
 
 	spin_lock_irqsave(&qp->sq.sq_lock, flags);
 
-	if (qp->is_user)
-		full = queue_full(sq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		full = queue_full(sq->queue, QUEUE_TYPE_KERNEL);
+	full = queue_full(sq->queue, QUEUE_TYPE_TO_DRIVER);
 
 	if (unlikely(full)) {
 		spin_unlock_irqrestore(&qp->sq.sq_lock, flags);
 		return -ENOMEM;
 	}
 
-	if (qp->is_user)
-		send_wqe = producer_addr(sq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		send_wqe = producer_addr(sq->queue, QUEUE_TYPE_KERNEL);
-
+	send_wqe = queue_producer_addr(sq->queue, QUEUE_TYPE_TO_DRIVER);
 	init_send_wqe(qp, ibwr, mask, length, send_wqe);
 
-	if (qp->is_user)
-		advance_producer(sq->queue, QUEUE_TYPE_FROM_USER);
-	else
-		advance_producer(sq->queue, QUEUE_TYPE_KERNEL);
+	queue_advance_producer(sq->queue, QUEUE_TYPE_TO_DRIVER);
 
 	spin_unlock_irqrestore(&qp->sq.sq_lock, flags);
 
@@ -842,18 +821,12 @@ static int rxe_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
 
 	spin_lock_irqsave(&cq->cq_lock, flags);
 	for (i = 0; i < num_entries; i++) {
-		if (cq->is_user)
-			cqe = queue_head(cq->queue, QUEUE_TYPE_TO_USER);
-		else
-			cqe = queue_head(cq->queue, QUEUE_TYPE_KERNEL);
+		cqe = queue_head(cq->queue, QUEUE_TYPE_FROM_DRIVER);
 		if (!cqe)
 			break;
 
 		memcpy(wc++, &cqe->ibwc, sizeof(*wc));
-		if (cq->is_user)
-			advance_consumer(cq->queue, QUEUE_TYPE_TO_USER);
-		else
-			advance_consumer(cq->queue, QUEUE_TYPE_KERNEL);
+		queue_advance_consumer(cq->queue, QUEUE_TYPE_FROM_DRIVER);
 	}
 	spin_unlock_irqrestore(&cq->cq_lock, flags);
 
@@ -865,10 +838,7 @@ static int rxe_peek_cq(struct ib_cq *ibcq, int wc_cnt)
 	struct rxe_cq *cq = to_rcq(ibcq);
 	int count;
 
-	if (cq->is_user)
-		count = queue_count(cq->queue, QUEUE_TYPE_TO_USER);
-	else
-		count = queue_count(cq->queue, QUEUE_TYPE_KERNEL);
+	count = queue_count(cq->queue, QUEUE_TYPE_FROM_DRIVER);
 
 	return (count > wc_cnt) ? wc_cnt : count;
 }
@@ -884,10 +854,7 @@ static int rxe_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
 	if (cq->notify != IB_CQ_NEXT_COMP)
 		cq->notify = flags & IB_CQ_SOLICITED_MASK;
 
-	if (cq->is_user)
-		empty = queue_empty(cq->queue, QUEUE_TYPE_TO_USER);
-	else
-		empty = queue_empty(cq->queue, QUEUE_TYPE_KERNEL);
+	empty = queue_empty(cq->queue, QUEUE_TYPE_FROM_DRIVER);
 
 	if ((flags & IB_CQ_REPORT_MISSED_EVENTS) && !empty)
 		ret = 1;