IB/qib: Modify software pma counters to use percpu variables

The counters, unicast_xmit, unicast_rcv, multicast_xmit, multicast_rcv
are now maintained as percpu variables.

The mad code is modified to add a z_ latch so that the percpu counters
monotonically increase with appropriate adjustments in the reset,
read logic to maintain the z_ latch.

This patch also corrects the fact the unitcast_xmit wasn't handled
at all for UC and RC QPs.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 36 insertions, 8 deletions

diff --git a/drivers/infiniband/hw/qib/qib_mad.c b/drivers/infiniband/hw/qib/qib_mad.c
index ccb119143d20..edad991d60ed 100644
--- a/drivers/infiniband/hw/qib/qib_mad.c
+++ b/drivers/infiniband/hw/qib/qib_mad.c
@@ -1634,6 +1634,23 @@ static int pma_get_portcounters_cong(struct ib_pma_mad *pmp,
 	return reply((struct ib_smp *)pmp);
 }
 
+static void qib_snapshot_pmacounters(
+	struct qib_ibport *ibp,
+	struct qib_pma_counters *pmacounters)
+{
+	struct qib_pma_counters *p;
+	int cpu;
+
+	memset(pmacounters, 0, sizeof(*pmacounters));
+	for_each_possible_cpu(cpu) {
+		p = per_cpu_ptr(ibp->pmastats, cpu);
+		pmacounters->n_unicast_xmit += p->n_unicast_xmit;
+		pmacounters->n_unicast_rcv += p->n_unicast_rcv;
+		pmacounters->n_multicast_xmit += p->n_multicast_xmit;
+		pmacounters->n_multicast_rcv += p->n_multicast_rcv;
+	}
+}
+
 static int pma_get_portcounters_ext(struct ib_pma_mad *pmp,
 				    struct ib_device *ibdev, u8 port)
 {
@@ -1642,6 +1659,7 @@ static int pma_get_portcounters_ext(struct ib_pma_mad *pmp,
 	struct qib_ibport *ibp = to_iport(ibdev, port);
 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 	u64 swords, rwords, spkts, rpkts, xwait;
+	struct qib_pma_counters pma;
 	u8 port_select = p->port_select;
 
 	memset(pmp->data, 0, sizeof(pmp->data));
@@ -1664,10 +1682,17 @@ static int pma_get_portcounters_ext(struct ib_pma_mad *pmp,
 	p->port_rcv_data = cpu_to_be64(rwords);
 	p->port_xmit_packets = cpu_to_be64(spkts);
 	p->port_rcv_packets = cpu_to_be64(rpkts);
-	p->port_unicast_xmit_packets = cpu_to_be64(ibp->n_unicast_xmit);
-	p->port_unicast_rcv_packets = cpu_to_be64(ibp->n_unicast_rcv);
-	p->port_multicast_xmit_packets = cpu_to_be64(ibp->n_multicast_xmit);
-	p->port_multicast_rcv_packets = cpu_to_be64(ibp->n_multicast_rcv);
+
+	qib_snapshot_pmacounters(ibp, &pma);
+
+	p->port_unicast_xmit_packets = cpu_to_be64(pma.n_unicast_xmit
+		- ibp->z_unicast_xmit);
+	p->port_unicast_rcv_packets = cpu_to_be64(pma.n_unicast_rcv
+		- ibp->z_unicast_rcv);
+	p->port_multicast_xmit_packets = cpu_to_be64(pma.n_multicast_xmit
+		- ibp->z_multicast_xmit);
+	p->port_multicast_rcv_packets = cpu_to_be64(pma.n_multicast_rcv
+		- ibp->z_multicast_rcv);
 
 bail:
 	return reply((struct ib_smp *) pmp);
@@ -1795,6 +1820,7 @@ static int pma_set_portcounters_ext(struct ib_pma_mad *pmp,
 	struct qib_ibport *ibp = to_iport(ibdev, port);
 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 	u64 swords, rwords, spkts, rpkts, xwait;
+	struct qib_pma_counters pma;
 
 	qib_snapshot_counters(ppd, &swords, &rwords, &spkts, &rpkts, &xwait);
 
@@ -1810,17 +1836,19 @@ static int pma_set_portcounters_ext(struct ib_pma_mad *pmp,
 	if (p->counter_select & IB_PMA_SELX_PORT_RCV_PACKETS)
 		ibp->z_port_rcv_packets = rpkts;
 
+	qib_snapshot_pmacounters(ibp, &pma);
+
 	if (p->counter_select & IB_PMA_SELX_PORT_UNI_XMIT_PACKETS)
-		ibp->n_unicast_xmit = 0;
+		ibp->z_unicast_xmit = pma.n_unicast_xmit;
 
 	if (p->counter_select & IB_PMA_SELX_PORT_UNI_RCV_PACKETS)
-		ibp->n_unicast_rcv = 0;
+		ibp->z_unicast_rcv = pma.n_unicast_rcv;
 
 	if (p->counter_select & IB_PMA_SELX_PORT_MULTI_XMIT_PACKETS)
-		ibp->n_multicast_xmit = 0;
+		ibp->z_multicast_xmit = pma.n_multicast_xmit;
 
 	if (p->counter_select & IB_PMA_SELX_PORT_MULTI_RCV_PACKETS)
-		ibp->n_multicast_rcv = 0;
+		ibp->z_multicast_rcv = pma.n_multicast_rcv;
 
 	return pma_get_portcounters_ext(pmp, ibdev, port);
 }