Merge pull request #1495 from selvintxavier/bug_fixes

bnxt_re/lib: driver fixes in resize_cq path

Author: rleon

providers/bnxt_re/db.c

@@ -169,12 +169,33 @@ void bnxt_re_ring_srq_arm(struct bnxt_re_srq *srq)
 	bnxt_re_ring_db(srq->udpi, &hdr);
 }
 
+/*
+ * During CQ resize, it is expected that the epoch needs to be maintained when
+ * switching from the old CQ to the new resized CQ.
+ *
+ * On the first CQ DB excecuted on the new CQ, we need to check if the index we
+ * are writing is less than the last index written for the old CQ. If that is
+ * the case, we need to flip the epoch so the ASIC does not get confused and
+ * think the CQ DB is out of order and therefore drop the DB (note the logic
+ * in the ASIC that checks CQ DB ordering is not aware of the CQ resize).
+ */
+static void bnxt_re_cq_resize_check(struct bnxt_re_queue *cqq)
+{
+	if (unlikely(cqq->cq_resized)) {
+		if (cqq->head < cqq->old_head)
+			cqq->flags ^= 1UL << BNXT_RE_FLAG_EPOCH_HEAD_SHIFT;
+
+		cqq->cq_resized = false;
+	}
+}
+
 void bnxt_re_ring_cq_db(struct bnxt_re_cq *cq)
 {
 	struct bnxt_re_db_hdr hdr;
 	uint32_t epoch;
 
 	bnxt_re_do_pacing(cq->cntx, &cq->rand);
+	bnxt_re_cq_resize_check(cq->cqq);
 	epoch = (cq->cqq->flags & BNXT_RE_FLAG_EPOCH_HEAD_MASK) << BNXT_RE_DB_EPOCH_HEAD_SHIFT;
 	bnxt_re_init_db_hdr(&hdr, cq->cqq->head | epoch, cq->cqid, 0, BNXT_RE_QUE_TYPE_CQ);
 	bnxt_re_ring_db(cq->udpi, &hdr);
@@ -195,6 +216,7 @@ void bnxt_re_ring_cq_arm_db(struct bnxt_re_cq *cq, uint8_t aflag)
 	}
 
 	bnxt_re_do_pacing(cq->cntx, &cq->rand);
+	bnxt_re_cq_resize_check(cq->cqq);
 	epoch = (cq->cqq->flags & BNXT_RE_FLAG_EPOCH_HEAD_MASK) <<  BNXT_RE_DB_EPOCH_HEAD_SHIFT;
 	bnxt_re_init_db_hdr(&hdr, cq->cqq->head | epoch, cq->cqid, toggle, aflag);
 	bnxt_re_ring_db(cq->udpi, &hdr);

providers/bnxt_re/memory.h

@@ -87,6 +87,14 @@ struct bnxt_re_queue {
 	pthread_spinlock_t qlock;
 	uint32_t msn;
 	uint32_t msn_tbl_sz;
+	/*
+	 * This flag is set when CQ is resized. It will be cleared after the
+	 * first CQE is received on the newly resized CQ
+	 */
+	bool cq_resized;
+
+	/* this tracks the 'head' index on the old CQ before resizing */
+	uint32_t old_head;
 };
 
 

providers/bnxt_re/verbs.c

@@ -420,14 +420,17 @@ static void bnxt_re_resize_cq_complete(struct bnxt_re_cq *cq)
 	cq->resize_mem = NULL;
 	cq->cqq->va = cq->mem->va_head;
 
+	/* mark the CQ resize flag and save the old head index */
+	cq->cqq->cq_resized = true;
+	cq->cqq->old_head = cq->cqq->head;
+
 	cq->cqq->depth = cq->mem->pad;
 	cq->cqq->stride = cntx->rdev->cqe_size;
 	cq->cqq->head = 0;
 	cq->cqq->tail = 0;
 	cq->phase = BNXT_RE_QUEUE_START_PHASE;
 	/* Reset epoch portion of the flags */
-	cq->cqq->flags &= ~(BNXT_RE_FLAG_EPOCH_TAIL_MASK |
-			    BNXT_RE_FLAG_EPOCH_HEAD_MASK);
+	cq->cqq->flags &= ~(BNXT_RE_FLAG_EPOCH_TAIL_MASK);
 	bnxt_re_ring_cq_arm_db(cq, BNXT_RE_QUE_TYPE_CQ_CUT_ACK);
 }
 
@@ -438,6 +441,8 @@ int bnxt_re_resize_cq(struct ibv_cq *ibvcq, int ncqe)
 	struct bnxt_re_cq *cq = to_bnxt_re_cq(ibvcq);
 	struct ib_uverbs_resize_cq_resp resp = {};
 	struct ubnxt_re_resize_cq cmd = {};
+	uint16_t msec_wait = 100;
+	uint16_t exit_cnt = 20;
 	int rc = 0;
 
 	if (ncqe > dev->max_cq_depth)
@@ -488,6 +493,13 @@ int bnxt_re_resize_cq(struct ibv_cq *ibvcq, int ncqe)
 			list_add_tail(&cq->prev_cq_head, &compl->list);
 			compl = NULL;
 			memset(&tmp_wc, 0, sizeof(tmp_wc));
+		} else {
+			exit_cnt--;
+			if (unlikely(!exit_cnt)) {
+				rc = -EIO;
+				break;
+			}
+			bnxt_re_sub_sec_busy_wait(msec_wait * 1000000);
 		}
 	}
 done:
@@ -544,6 +556,7 @@ static uint8_t bnxt_re_poll_err_scqe(struct bnxt_re_qp *qp,
 	status = (le32toh(hdr->flg_st_typ_ph) >> BNXT_RE_BCQE_STATUS_SHIFT) &
 		  BNXT_RE_BCQE_STATUS_MASK;
 	ibvwc->status = bnxt_re_to_ibv_wc_status(status, true);
+	ibvwc->vendor_err = status;
 	ibvwc->wc_flags = 0;
 	ibvwc->wr_id = swrid->wrid;
 	ibvwc->qp_num = qp->qpid;
@@ -663,6 +676,7 @@ static int bnxt_re_poll_err_rcqe(struct bnxt_re_qp *qp, struct ibv_wc *ibvwc,
 		return 0;
 
 	ibvwc->status = bnxt_re_to_ibv_wc_status(status, false);
+	ibvwc->vendor_err = status;
 	ibvwc->qp_num = qp->qpid;
 	ibvwc->opcode = IBV_WC_RECV;
 	ibvwc->byte_len = 0;