[for-next 3/3] RDMA/ionic: key recv completions by producer index

[Abhijit Gangurde <abhijit.gangurde@amd.com>]

The recv completion's wqe_idx is the RQ producer index. Store the
wr_id at that slot and write the same index into the posted WQE. A
posted flag on the slot rejects a completion for a recv that is not
outstanding.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
---
 .../infiniband/hw/ionic/ionic_controlpath.c   | 19 ++++-----------
 drivers/infiniband/hw/ionic/ionic_datapath.c  | 24 +++++++++----------
 drivers/infiniband/hw/ionic/ionic_ibdev.h     |  6 +----
 3 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/drivers/infiniband/hw/ionic/ionic_controlpath.c b/drivers/infiniband/hw/ionic/ionic_controlpath.c
index 1738635bacf4..8a0a1575a339 100644
--- a/drivers/infiniband/hw/ionic/ionic_controlpath.c
+++ b/drivers/infiniband/hw/ionic/ionic_controlpath.c
@@ -2195,8 +2195,8 @@ static int ionic_rq_init(struct ionic_ibdev *dev, struct ionic_ctx *ctx,
 			 struct ionic_tbl_buf *buf, int max_wr, int max_sge,
 			 int rq_spec, struct ib_udata *udata)
 {
-	int rc = 0, i;
 	u32 wqe_size;
+	int rc = 0;
 
 	rc = -EINVAL;
 
@@ -2258,16 +2258,11 @@ static int ionic_rq_init(struct ionic_ibdev *dev, struct ionic_ctx *ctx,
 
 		ionic_queue_dbell_init(&rq->q, rq->qid);
 
-		rq->meta = kmalloc_objs(*rq->meta, (u32)rq->q.mask + 1);
+		rq->meta = kzalloc_objs(*rq->meta, (u32)rq->q.mask + 1);
 		if (!rq->meta) {
 			rc = -ENOMEM;
 			goto err_rq_meta;
 		}
-
-		for (i = 0; i < rq->q.mask; ++i)
-			rq->meta[i].next = &rq->meta[i + 1];
-		rq->meta[i].next = IONIC_META_LAST;
-		rq->meta_head = &rq->meta[0];
 	}
 
 	ionic_rq_init_cmb(dev, rq, udata);
@@ -2638,7 +2633,6 @@ static void ionic_reset_qp(struct ionic_ibdev *dev, struct ionic_qp *qp)
 {
 	unsigned long irqflags;
 	struct ionic_cq *cq;
-	int i;
 
 	local_irq_save(irqflags);
 
@@ -2673,12 +2667,9 @@ static void ionic_reset_qp(struct ionic_ibdev *dev, struct ionic_qp *qp)
 		qp->rq.flush = false;
 		qp->rq.q.prod = 0;
 		qp->rq.q.cons = 0;
-		if (qp->rq.meta) {
-			for (i = 0; i < qp->rq.q.mask; ++i)
-				qp->rq.meta[i].next = &qp->rq.meta[i + 1];
-			qp->rq.meta[i].next = IONIC_META_LAST;
-		}
-		qp->rq.meta_head = &qp->rq.meta[0];
+		if (qp->rq.meta)
+			memset(qp->rq.meta, 0,
+			       (qp->rq.q.mask + 1) * sizeof(*qp->rq.meta));
 		spin_unlock(&qp->rq.lock);
 	}
 
diff --git a/drivers/infiniband/hw/ionic/ionic_datapath.c b/drivers/infiniband/hw/ionic/ionic_datapath.c
index 422e53e21054..f1354dae089c 100644
--- a/drivers/infiniband/hw/ionic/ionic_datapath.c
+++ b/drivers/infiniband/hw/ionic/ionic_datapath.c
@@ -53,7 +53,7 @@ static int ionic_flush_recv(struct ionic_qp *qp, struct ib_wc *wc)
 
 	/* wqe_idx must indicate a request that is outstanding */
 	meta = &qp->rq.meta[wqe_idx];
-	if (unlikely(meta->next != IONIC_META_POSTED)) {
+	if (unlikely(!meta->posted)) {
 		ibdev_warn(qp->ibqp.device,
 			   "flush qp %u recv index %llu not posted\n",
 			   qp->qpid, (unsigned long long)wqe_idx);
@@ -68,8 +68,7 @@ static int ionic_flush_recv(struct ionic_qp *qp, struct ib_wc *wc)
 	wc->wr_id = meta->wrid;
 	wc->qp = &qp->ibqp;
 
-	meta->next = qp->rq.meta_head;
-	qp->rq.meta_head = meta;
+	meta->posted = false;
 
 	return 1;
 }
@@ -172,14 +171,13 @@ static int ionic_poll_recv(struct ionic_ibdev *dev, struct ionic_cq *cq,
 
 	/* wqe_idx must indicate a request that is outstanding */
 	meta = &qp->rq.meta[wqe_idx];
-	if (unlikely(meta->next != IONIC_META_POSTED)) {
+	if (unlikely(!meta->posted)) {
 		ibdev_warn(&dev->ibdev,
 			   "qp %u recv index %u not posted\n", qp->qpid, wqe_idx);
 		return -EIO;
 	}
 
-	meta->next = qp->rq.meta_head;
-	qp->rq.meta_head = meta;
+	meta->posted = false;
 
 	memset(wc, 0, sizeof(*wc));
 
@@ -1199,9 +1197,12 @@ static int ionic_prep_recv(struct ionic_qp *qp,
 	if (wqe->base.flags & cpu_to_be16(IONIC_V1_FLAG_FENCE))
 		return -EAGAIN;
 
-	meta = qp->rq.meta_head;
-	if (unlikely(meta == IONIC_META_LAST) ||
-	    unlikely(meta == IONIC_META_POSTED))
+	/*
+	 * The completion carries this producer index, so the wr_id
+	 * lives in the meta slot at the same index.
+	 */
+	meta = &qp->rq.meta[qp->rq.q.prod];
+	if (unlikely(meta->posted))
 		return -EIO;
 
 	ionic_prep_rq_wqe(qp, wqe);
@@ -1216,7 +1217,7 @@ static int ionic_prep_recv(struct ionic_qp *qp,
 
 	meta->wrid = wr->wr_id;
 
-	wqe->base.wqe_idx = cpu_to_le64(meta - qp->rq.meta);
+	wqe->base.wqe_idx = cpu_to_le64(qp->rq.q.prod);
 	wqe->base.num_sge_key = wr->num_sge;
 
 	/* total length for recv goes in base imm_data_key */
@@ -1224,8 +1225,7 @@ static int ionic_prep_recv(struct ionic_qp *qp,
 
 	ionic_queue_produce(&qp->rq.q);
 
-	qp->rq.meta_head = meta->next;
-	meta->next = IONIC_META_POSTED;
+	meta->posted = true;
 
 	return 0;
 }
diff --git a/drivers/infiniband/hw/ionic/ionic_ibdev.h b/drivers/infiniband/hw/ionic/ionic_ibdev.h
index cf4b85355f26..127b79cdfc45 100644
--- a/drivers/infiniband/hw/ionic/ionic_ibdev.h
+++ b/drivers/infiniband/hw/ionic/ionic_ibdev.h
@@ -40,9 +40,6 @@
 #define IONIC_MAX_SRQ_LIMIT	0xffff
 #define IONIC_MAX_SRQ_DEPTH	0xffff
 
-#define IONIC_META_LAST		((void *)1ul)
-#define IONIC_META_POSTED	((void *)2ul)
-
 #define IONIC_CQ_GRACE 100
 
 #define IONIC_ROCE_UDP_SPORT	28272
@@ -242,8 +239,8 @@ struct ionic_sq_meta {
 };
 
 struct ionic_rq_meta {
-	struct ionic_rq_meta	*next;
 	u64			wrid;
+	bool			posted;
 };
 
 struct ionic_rq {
@@ -257,7 +254,6 @@ struct ionic_rq {
 	struct rdma_user_mmap_entry	*mmap_cmb;
 
 	struct ionic_rq_meta		*meta;
-	struct ionic_rq_meta		*meta_head;
 	struct ib_umem			*umem;
 
 	int				spec;
-- 
2.43.0