nfp: abm: report statistics from RED offload

Report basic and extended RED statistics back to TC.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 92 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/abm/main.c b/drivers/net/ethernet/netronome/nfp/abm/main.c
index 22251d88c958..d0c21899a8b7 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/main.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/main.c
@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 #include <net/pkt_cls.h>
 #include <net/pkt_sched.h>
+#include <net/red.h>
 
 #include "../nfpcore/nfp.h"
 #include "../nfpcore/nfp_cpp.h"
@@ -57,6 +58,23 @@ static u32 nfp_abm_portid(enum nfp_repr_type rtype, unsigned int id)
 	       FIELD_PREP(NFP_ABM_PORTID_ID, id);
 }
 
+static int nfp_abm_reset_stats(struct nfp_abm_link *alink)
+{
+	int err;
+
+	err = nfp_abm_ctrl_read_stats(alink, &alink->qdiscs[0].stats);
+	if (err)
+		return err;
+	alink->qdiscs[0].stats.backlog_pkts = 0;
+	alink->qdiscs[0].stats.backlog_bytes = 0;
+
+	err = nfp_abm_ctrl_read_xstats(alink, &alink->qdiscs[0].xstats);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 static void
 nfp_abm_red_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
 		    u32 handle)
@@ -88,16 +106,86 @@ nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
 	if (err)
 		goto err_destroy;
 
+	/* Reset stats only on new qdisc */
+	if (alink->qdiscs[0].handle != opt->handle) {
+		err = nfp_abm_reset_stats(alink);
+		if (err)
+			goto err_destroy;
+	}
+
 	alink->qdiscs[0].handle = opt->handle;
 	port->tc_offload_cnt = 1;
 
 	return 0;
 err_destroy:
+	/* If the qdisc keeps on living, but we can't offload undo changes */
+	if (alink->qdiscs[0].handle == opt->handle) {
+		opt->set.qstats->qlen -= alink->qdiscs[0].stats.backlog_pkts;
+		opt->set.qstats->backlog -=
+			alink->qdiscs[0].stats.backlog_bytes;
+	}
 	if (alink->qdiscs[0].handle != TC_H_UNSPEC)
 		nfp_abm_red_destroy(netdev, alink, alink->qdiscs[0].handle);
 	return err;
 }
 
+static void
+nfp_abm_update_stats(struct nfp_alink_stats *new, struct nfp_alink_stats *old,
+		     struct tc_qopt_offload_stats *stats)
+{
+	_bstats_update(stats->bstats, new->tx_bytes - old->tx_bytes,
+		       new->tx_pkts - old->tx_pkts);
+	stats->qstats->qlen += new->backlog_pkts - old->backlog_pkts;
+	stats->qstats->backlog += new->backlog_bytes - old->backlog_bytes;
+	stats->qstats->overlimits += new->overlimits - old->overlimits;
+	stats->qstats->drops += new->drops - old->drops;
+}
+
+static int
+nfp_abm_red_stats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
+{
+	struct nfp_alink_stats *prev_stats;
+	struct nfp_alink_stats stats;
+	int err;
+
+	if (alink->qdiscs[0].handle != opt->handle)
+		return -EOPNOTSUPP;
+	prev_stats = &alink->qdiscs[0].stats;
+
+	err = nfp_abm_ctrl_read_stats(alink, &stats);
+	if (err)
+		return err;
+
+	nfp_abm_update_stats(&stats, prev_stats, &opt->stats);
+
+	*prev_stats = stats;
+
+	return 0;
+}
+
+static int
+nfp_abm_red_xstats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
+{
+	struct nfp_alink_xstats *prev_xstats;
+	struct nfp_alink_xstats xstats;
+	int err;
+
+	if (alink->qdiscs[0].handle != opt->handle)
+		return -EOPNOTSUPP;
+	prev_xstats = &alink->qdiscs[0].xstats;
+
+	err = nfp_abm_ctrl_read_xstats(alink, &xstats);
+	if (err)
+		return err;
+
+	opt->xstats->forced_mark += xstats.ecn_marked - prev_xstats->ecn_marked;
+	opt->xstats->pdrop += xstats.pdrop - prev_xstats->pdrop;
+
+	*prev_xstats = xstats;
+
+	return 0;
+}
+
 static int
 nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
 		     struct tc_red_qopt_offload *opt)
@@ -111,6 +199,10 @@ nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
 	case TC_RED_DESTROY:
 		nfp_abm_red_destroy(netdev, alink, opt->handle);
 		return 0;
+	case TC_RED_STATS:
+		return nfp_abm_red_stats(alink, opt);
+	case TC_RED_XSTATS:
+		return nfp_abm_red_xstats(alink, opt);
 	default:
 		return -EOPNOTSUPP;
 	}