IB/{rdmavt, hfi1, qib}: Add a counter for credit waits

This patch adds a counter for credit waits to assist field debugging.

Link: https://lore.kernel.org/r/20190911113047.126040.10857.stgit@awfm-01.aw.intel.com
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hfi1/chip.c

@@ -4101,6 +4101,7 @@ def_access_ibp_counter(rc_dupreq);
 def_access_ibp_counter(rdma_seq);
 def_access_ibp_counter(unaligned);
 def_access_ibp_counter(seq_naks);
+def_access_ibp_counter(rc_crwaits);
 
 static struct cntr_entry dev_cntrs[DEV_CNTR_LAST] = {
 [C_RCV_OVF] = RXE32_DEV_CNTR_ELEM(RcvOverflow, RCV_BUF_OVFL_CNT, CNTR_SYNTH),
@@ -5119,6 +5120,7 @@ static struct cntr_entry port_cntrs[PORT_CNTR_LAST] = {
 [C_SW_IBP_RDMA_SEQ] = SW_IBP_CNTR(RdmaSeq, rdma_seq),
 [C_SW_IBP_UNALIGNED] = SW_IBP_CNTR(Unaligned, unaligned),
 [C_SW_IBP_SEQ_NAK] = SW_IBP_CNTR(SeqNak, seq_naks),
+[C_SW_IBP_RC_CRWAITS] = SW_IBP_CNTR(RcCrWait, rc_crwaits),
 [C_SW_CPU_RC_ACKS] = CNTR_ELEM("RcAcks", 0, 0, CNTR_NORMAL,
 			       access_sw_cpu_rc_acks),
 [C_SW_CPU_RC_QACKS] = CNTR_ELEM("RcQacks", 0, 0, CNTR_NORMAL,

drivers/infiniband/hw/hfi1/chip.h

@@ -1245,6 +1245,7 @@ enum {
 	C_SW_IBP_RDMA_SEQ,
 	C_SW_IBP_UNALIGNED,
 	C_SW_IBP_SEQ_NAK,
+	C_SW_IBP_RC_CRWAITS,
 	C_SW_CPU_RC_ACKS,
 	C_SW_CPU_RC_QACKS,
 	C_SW_CPU_RC_DELAYED_COMP,

drivers/infiniband/hw/hfi1/rc.c

@@ -595,11 +595,8 @@ check_s_state:
 		case IB_WR_SEND_WITH_IMM:
 		case IB_WR_SEND_WITH_INV:
 			/* If no credit, return. */
-			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
-			    rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
-				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+			if (!rvt_rc_credit_avail(qp, wqe))
 				goto bail;
-			}
 			if (len > pmtu) {
 				qp->s_state = OP(SEND_FIRST);
 				len = pmtu;
@@ -632,11 +629,8 @@ check_s_state:
 			goto no_flow_control;
 		case IB_WR_RDMA_WRITE_WITH_IMM:
 			/* If no credit, return. */
-			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
-			    rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
-				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+			if (!rvt_rc_credit_avail(qp, wqe))
 				goto bail;
-			}
 no_flow_control:
 			put_ib_reth_vaddr(
 				wqe->rdma_wr.remote_addr,

drivers/infiniband/hw/qib/qib_rc.c

@@ -313,11 +313,8 @@ int qib_make_rc_req(struct rvt_qp *qp, unsigned long *flags)
 		case IB_WR_SEND:
 		case IB_WR_SEND_WITH_IMM:
 			/* If no credit, return. */
-			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
-			    rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
-				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+			if (!rvt_rc_credit_avail(qp, wqe))
 				goto bail;
-			}
 			if (len > pmtu) {
 				qp->s_state = OP(SEND_FIRST);
 				len = pmtu;
@@ -344,11 +341,8 @@ int qib_make_rc_req(struct rvt_qp *qp, unsigned long *flags)
 			goto no_flow_control;
 		case IB_WR_RDMA_WRITE_WITH_IMM:
 			/* If no credit, return. */
-			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
-			    rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
-				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+			if (!rvt_rc_credit_avail(qp, wqe))
 				goto bail;
-			}
 no_flow_control:
 			ohdr->u.rc.reth.vaddr =
 				cpu_to_be64(wqe->rdma_wr.remote_addr);

drivers/infiniband/hw/qib/qib_sysfs.c

@@ -436,6 +436,7 @@ QIB_DIAGC_ATTR(dmawait);
 QIB_DIAGC_ATTR(unaligned);
 QIB_DIAGC_ATTR(rc_dupreq);
 QIB_DIAGC_ATTR(rc_seqnak);
+QIB_DIAGC_ATTR(rc_crwaits);
 
 static struct attribute *diagc_default_attributes[] = {
 	&qib_diagc_attr_rc_resends.attr,
@@ -453,6 +454,7 @@ static struct attribute *diagc_default_attributes[] = {
 	&qib_diagc_attr_unaligned.attr,
 	&qib_diagc_attr_rc_dupreq.attr,
 	&qib_diagc_attr_rc_seqnak.attr,
+	&qib_diagc_attr_rc_crwaits.attr,
 	NULL
 };
 

include/rdma/rdma_vt.h

@@ -116,6 +116,7 @@ struct rvt_ibport {
 	u64 n_unaligned;
 	u64 n_rc_dupreq;
 	u64 n_rc_seqnak;
+	u64 n_rc_crwaits;
 	u16 pkey_violations;
 	u16 qkey_violations;
 	u16 mkey_violations;

include/rdma/rdmavt_qp.h

@@ -973,6 +973,41 @@ static inline void rvt_free_rq(struct rvt_rq *rq)
 	rq->wq = NULL;
 }
 
+/**
+ * rvt_to_iport - Get the ibport pointer
+ * @qp: the qp pointer
+ *
+ * This function returns the ibport pointer from the qp pointer.
+ */
+static inline struct rvt_ibport *rvt_to_iport(struct rvt_qp *qp)
+{
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	return rdi->ports[qp->port_num - 1];
+}
+
+/**
+ * rvt_rc_credit_avail - Check if there are enough RC credits for the request
+ * @qp: the qp
+ * @wqe: the request
+ *
+ * This function returns false when there are not enough credits for the given
+ * request and true otherwise.
+ */
+static inline bool rvt_rc_credit_avail(struct rvt_qp *qp, struct rvt_swqe *wqe)
+{
+	lockdep_assert_held(&qp->s_lock);
+	if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
+	    rvt_cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
+		struct rvt_ibport *rvp = rvt_to_iport(qp);
+
+		qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+		rvp->n_rc_crwaits++;
+		return false;
+	}
+	return true;
+}
+
 struct rvt_qp_iter *rvt_qp_iter_init(struct rvt_dev_info *rdi,
 				     u64 v,
 				     void (*cb)(struct rvt_qp *qp, u64 v));