efa: Fix CQ poll after QP destroy

After a QP has been destroyed there might still be pending CQEs. As an
optimization for some cases, poll functions ignore CQs that are not in
use by any QP, preventing completions from being read after destruction
of the last QP that uses this CQ. Remove this optimization.

Reviewed-by: Firas Jahjah <[email protected]>
Signed-off-by: Michael Margolin <[email protected]>

Author: mrgolin

providers/efa/verbs.c

@@ -769,9 +769,6 @@ static inline int efa_poll_sub_cqs(struct efa_cq *cq, struct ibv_wc *wc,
 		sub_cq = &cq->sub_cq_arr[cq->next_poll_idx++];
 		cq->next_poll_idx %= num_sub_cqs;
 
-		if (!sub_cq->ref_cnt)
-			continue;
-
 		err = efa_poll_sub_cq(cq, sub_cq, &qp, wc, extended);
 		if (err != ENOENT) {
 			cq->cc++;
@@ -896,7 +893,6 @@ static void efa_sub_cq_initialize(struct efa_sub_cq *sub_cq, uint8_t *buf,
 	sub_cq->buf = buf;
 	sub_cq->qmask = sub_cq_size - 1;
 	sub_cq->cqe_size = cqe_size;
-	sub_cq->ref_cnt = 0;
 }
 
 static struct ibv_cq_ex *create_cq(struct ibv_context *ibvctx,
@@ -1084,16 +1080,6 @@ int efa_destroy_cq(struct ibv_cq *ibvcq)
 	return 0;
 }
 
-static void efa_cq_inc_ref_cnt(struct efa_cq *cq, uint8_t sub_cq_idx)
-{
-	cq->sub_cq_arr[sub_cq_idx].ref_cnt++;
-}
-
-static void efa_cq_dec_ref_cnt(struct efa_cq *cq, uint8_t sub_cq_idx)
-{
-	cq->sub_cq_arr[sub_cq_idx].ref_cnt--;
-}
-
 static void efa_wq_terminate(struct efa_wq *wq, int pgsz)
 {
 	void *db_aligned;
@@ -1476,8 +1462,6 @@ static struct ibv_qp *create_qp(struct ibv_context *ibvctx,
 	struct efa_dev *dev = to_efa_dev(ibvctx->device);
 	struct efa_create_qp_resp resp = {};
 	struct efa_create_qp req = {};
-	struct efa_cq *send_cq;
-	struct efa_cq *recv_cq;
 	struct ibv_qp *ibvqp;
 	struct efa_qp *qp;
 	int err;
@@ -1535,16 +1519,6 @@ static struct ibv_qp *create_qp(struct ibv_context *ibvctx,
 	ctx->qp_table[ibvqp->qp_num & ctx->qp_table_sz_m1] = qp;
 	pthread_spin_unlock(&ctx->qp_table_lock);
 
-	send_cq = to_efa_cq(attr->send_cq);
-	pthread_spin_lock(&send_cq->lock);
-	efa_cq_inc_ref_cnt(send_cq, resp.send_sub_cq_idx);
-	pthread_spin_unlock(&send_cq->lock);
-
-	recv_cq = to_efa_cq(attr->recv_cq);
-	pthread_spin_lock(&recv_cq->lock);
-	efa_cq_inc_ref_cnt(recv_cq, resp.recv_sub_cq_idx);
-	pthread_spin_unlock(&recv_cq->lock);
-
 	if (attr->comp_mask & IBV_QP_INIT_ATTR_SEND_OPS_FLAGS) {
 		efa_qp_fill_wr_pfns(&qp->verbs_qp.qp_ex, attr);
 		qp->verbs_qp.comp_mask |= VERBS_QP_EX;
@@ -1725,9 +1699,6 @@ int efa_destroy_qp(struct ibv_qp *ibvqp)
 	pthread_spin_lock(&ctx->qp_table_lock);
 	efa_lock_cqs(ibvqp);
 
-	efa_cq_dec_ref_cnt(to_efa_cq(ibvqp->send_cq), qp->sq.wq.sub_cq_idx);
-	efa_cq_dec_ref_cnt(to_efa_cq(ibvqp->recv_cq), qp->rq.wq.sub_cq_idx);
-
 	ctx->qp_table[ibvqp->qp_num & ctx->qp_table_sz_m1] = NULL;
 
 	efa_unlock_cqs(ibvqp);