diff mbox series

[net-next,11/13] nfp: abm: reset RED's child based on limit

Message ID 20181112225819.29823-12-jakub.kicinski@netronome.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series nfp: abm: track all Qdiscs | expand

Commit Message

Jakub Kicinski Nov. 12, 2018, 10:58 p.m. UTC 
RED qdisc will replace its child Qdisc with a new FIFO queue if
it is reconfigured and the limit parameter is not 0.

This means that when it's created with limit of 0 it will have no FIFO,
and all packets will be dropped.  If it's changed and limit is specified
it will loose its existing child (implicit graft).  Make sure we mark
RED Qdisc child as NFP_QDISC_UNTRACKED if its not the expected FIFO.

nfp_abm_qdisc_replace() will return 1 if Qdisc already existed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
---
 .../net/ethernet/netronome/nfp/abm/qdisc.c    | 27 +++++++++++++++----
 1 file changed, 22 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
index 151d2dafbc76..1b3c0b5b52bf 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c
@@ -196,7 +196,7 @@  nfp_abm_qdisc_replace(struct net_device *netdev, struct nfp_abm_link *alink,
 	if (*qdisc) {
 		if (WARN_ON((*qdisc)->type != type))
 			return -EINVAL;
-		return 0;
+		return 1;
 	}
 
 	*qdisc = nfp_abm_qdisc_alloc(netdev, alink, type, parent_handle, handle,
@@ -357,11 +357,24 @@  nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
 	i = nfp_abm_red_find(alink, opt);
 	existing = i >= 0;
 
-	if (ret) {
+	if (ret < 0) {
 		err = ret;
 		goto err_destroy;
 	}
 
+	/* If limit != 0 child gets reset */
+	if (opt->set.limit) {
+		if (nfp_abm_qdisc_child_valid(qdisc, 0))
+			qdisc->children[0]->use_cnt--;
+		qdisc->children[0] = NULL;
+	} else {
+		/* Qdisc was just allocated without a limit will use noop_qdisc,
+		 * i.e. a block hole.
+		 */
+		if (!ret)
+			qdisc->children[0] = NFP_QDISC_UNTRACKED;
+	}
+
 	if (!nfp_abm_red_check_params(alink, opt)) {
 		err = -EINVAL;
 		goto err_destroy;
@@ -533,10 +546,14 @@  nfp_abm_mq_create(struct net_device *netdev, struct nfp_abm_link *alink,
 		  struct tc_mq_qopt_offload *opt)
 {
 	struct nfp_qdisc *qdisc;
+	int ret;
 
-	return nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
-				     TC_H_ROOT, opt->handle,
-				     alink->total_queues, &qdisc);
+	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
+				    TC_H_ROOT, opt->handle, alink->total_queues,
+				    &qdisc);
+	if (ret < 0)
+		return ret;
+	return 0;
 }
 
 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,