[PATCH for-next] RDMA/rxe: Simplify cq->notify code

[PATCH for-next] RDMA/rxe: Simplify cq->notify code

[Bob Pearson]

The flags parameter to the request notify verb is a bitmask. But,
rxe driver treats cq->notify as an int. If someone ever set both
the IB_CQ_SOLICITED and the IB_CQ_NEXT_COMP bits rxe_cq_post
could fail to generate a completion event. This patch treats
the notify flags as a bit mask consistently and can handle the
above case correctly.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_cq.c    | 5 ++---
 drivers/infiniband/sw/rxe/rxe_verbs.c | 5 +----
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_cq.c b/drivers/infiniband/sw/rxe/rxe_cq.c
index 6ca2a05b6a2a..d5486cbb3f10 100644
--- a/drivers/infiniband/sw/rxe/rxe_cq.c
+++ b/drivers/infiniband/sw/rxe/rxe_cq.c
@@ -113,10 +113,9 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited)
 
 	queue_advance_producer(cq->queue, QUEUE_TYPE_TO_CLIENT);
 
-	if ((cq->notify == IB_CQ_NEXT_COMP) ||
-	    (cq->notify == IB_CQ_SOLICITED && solicited)) {
+	if ((cq->notify & IB_CQ_NEXT_COMP) ||
+	    (cq->notify & IB_CQ_SOLICITED && solicited)) {
 		cq->notify = 0;
-
 		cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
 	}
 
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index f6396333bcef..c7c673637dea 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -1181,14 +1181,11 @@ static int rxe_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
 	unsigned long irq_flags;
 
 	spin_lock_irqsave(&cq->cq_lock, irq_flags);
-	if (cq->notify != IB_CQ_NEXT_COMP)
-		cq->notify = flags & IB_CQ_SOLICITED_MASK;
-
+	cq->notify |= flags & IB_CQ_SOLICITED_MASK;
 	empty = queue_empty(cq->queue, QUEUE_TYPE_TO_ULP);
 
 	if ((flags & IB_CQ_REPORT_MISSED_EVENTS) && !empty)
 		ret = 1;
-
 	spin_unlock_irqrestore(&cq->cq_lock, irq_flags);
 
 	return ret;
-- 
2.39.2

Re: [PATCH for-next] RDMA/rxe: Simplify cq->notify code

[Jason Gunthorpe]

On Mon, Jun 12, 2023 at 11:22:45AM -0500, Bob Pearson wrote:
> The flags parameter to the request notify verb is a bitmask. But,
> rxe driver treats cq->notify as an int. If someone ever set both
> the IB_CQ_SOLICITED and the IB_CQ_NEXT_COMP bits rxe_cq_post
> could fail to generate a completion event. This patch treats
> the notify flags as a bit mask consistently and can handle the
> above case correctly.
> 
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
> ---
>  drivers/infiniband/sw/rxe/rxe_cq.c    | 5 ++---
>  drivers/infiniband/sw/rxe/rxe_verbs.c | 5 +----
>  2 files changed, 3 insertions(+), 7 deletions(-)

Applied to for-next, thanks

Jason