From 990e35ecba1cb8ebee4ad4a028735e24f4615417 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Mon, 23 Jul 2018 17:08:00 -0700 Subject: cbs: Add support for the graft function This will allow to install a child qdisc under cbs. The main use case is to install ETF (Earliest TxTime First) qdisc under cbs, so there's another level of control for time-sensitive traffic. Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller --- net/sched/sch_cbs.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 125 insertions(+), 9 deletions(-) (limited to 'net/sched/sch_cbs.c') diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index cdd96b9a27bc..e26a24017faa 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -78,18 +78,42 @@ struct cbs_sched_data { s64 sendslope; /* in bytes/s */ s64 idleslope; /* in bytes/s */ struct qdisc_watchdog watchdog; - int (*enqueue)(struct sk_buff *skb, struct Qdisc *sch); + int (*enqueue)(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free); struct sk_buff *(*dequeue)(struct Qdisc *sch); + struct Qdisc *qdisc; }; -static int cbs_enqueue_offload(struct sk_buff *skb, struct Qdisc *sch) +static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch, + struct Qdisc *child, + struct sk_buff **to_free) { - return qdisc_enqueue_tail(skb, sch); + int err; + + err = child->ops->enqueue(skb, child, to_free); + if (err != NET_XMIT_SUCCESS) + return err; + + qdisc_qstats_backlog_inc(sch, skb); + sch->q.qlen++; + + return NET_XMIT_SUCCESS; } -static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch) +static int cbs_enqueue_offload(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free) { struct cbs_sched_data *q = qdisc_priv(sch); + struct Qdisc *qdisc = q->qdisc; + + return cbs_child_enqueue(skb, sch, qdisc, to_free); +} + +static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free) +{ + struct cbs_sched_data *q = qdisc_priv(sch); + struct Qdisc *qdisc = q->qdisc; if (sch->q.qlen == 0 && q->credits > 0) { /* We need to stop accumulating credits when there's @@ -99,7 +123,7 @@ static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch) q->last = ktime_get_ns(); } - return qdisc_enqueue_tail(skb, sch); + return cbs_child_enqueue(skb, sch, qdisc, to_free); } static int cbs_enqueue(struct sk_buff *skb, struct Qdisc *sch, @@ -107,7 +131,7 @@ static int cbs_enqueue(struct sk_buff *skb, struct Qdisc *sch, { struct cbs_sched_data *q = qdisc_priv(sch); - return q->enqueue(skb, sch); + return q->enqueue(skb, sch, to_free); } /* timediff is in ns, slope is in bytes/s */ @@ -132,9 +156,25 @@ static s64 credits_from_len(unsigned int len, s64 slope, s64 port_rate) return div64_s64(len * slope, port_rate); } +static struct sk_buff *cbs_child_dequeue(struct Qdisc *sch, struct Qdisc *child) +{ + struct sk_buff *skb; + + skb = child->ops->dequeue(child); + if (!skb) + return NULL; + + qdisc_qstats_backlog_dec(sch, skb); + qdisc_bstats_update(sch, skb); + sch->q.qlen--; + + return skb; +} + static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) { struct cbs_sched_data *q = qdisc_priv(sch); + struct Qdisc *qdisc = q->qdisc; s64 now = ktime_get_ns(); struct sk_buff *skb; s64 credits; @@ -157,8 +197,7 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) return NULL; } } - - skb = qdisc_dequeue_head(sch); + skb = cbs_child_dequeue(sch, qdisc); if (!skb) return NULL; @@ -178,7 +217,10 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) static struct sk_buff *cbs_dequeue_offload(struct Qdisc *sch) { - return qdisc_dequeue_head(sch); + struct cbs_sched_data *q = qdisc_priv(sch); + struct Qdisc *qdisc = q->qdisc; + + return cbs_child_dequeue(sch, qdisc); } static struct sk_buff *cbs_dequeue(struct Qdisc *sch) @@ -310,6 +352,13 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt, return -EINVAL; } + q->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + sch->handle, extack); + if (!q->qdisc) + return -ENOMEM; + + qdisc_hash_add(q->qdisc, false); + q->queue = sch->dev_queue - netdev_get_tx_queue(dev, 0); q->enqueue = cbs_enqueue_soft; @@ -328,6 +377,9 @@ static void cbs_destroy(struct Qdisc *sch) qdisc_watchdog_cancel(&q->watchdog); cbs_disable_offload(dev, q); + + if (q->qdisc) + qdisc_destroy(q->qdisc); } static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb) @@ -356,8 +408,72 @@ nla_put_failure: return -1; } +static int cbs_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm) +{ + struct cbs_sched_data *q = qdisc_priv(sch); + + if (cl != 1 || !q->qdisc) /* only one class */ + return -ENOENT; + + tcm->tcm_handle |= TC_H_MIN(1); + tcm->tcm_info = q->qdisc->handle; + + return 0; +} + +static int cbs_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, + struct Qdisc **old, struct netlink_ext_ack *extack) +{ + struct cbs_sched_data *q = qdisc_priv(sch); + + if (!new) { + new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + sch->handle, NULL); + if (!new) + new = &noop_qdisc; + } + + *old = qdisc_replace(sch, new, &q->qdisc); + return 0; +} + +static struct Qdisc *cbs_leaf(struct Qdisc *sch, unsigned long arg) +{ + struct cbs_sched_data *q = qdisc_priv(sch); + + return q->qdisc; +} + +static unsigned long cbs_find(struct Qdisc *sch, u32 classid) +{ + return 1; +} + +static void cbs_walk(struct Qdisc *sch, struct qdisc_walker *walker) +{ + if (!walker->stop) { + if (walker->count >= walker->skip) { + if (walker->fn(sch, 1, walker) < 0) { + walker->stop = 1; + return; + } + } + walker->count++; + } +} + +static const struct Qdisc_class_ops cbs_class_ops = { + .graft = cbs_graft, + .leaf = cbs_leaf, + .find = cbs_find, + .walk = cbs_walk, + .dump = cbs_dump_class, +}; + static struct Qdisc_ops cbs_qdisc_ops __read_mostly = { .id = "cbs", + .cl_ops = &cbs_class_ops, .priv_size = sizeof(struct cbs_sched_data), .enqueue = cbs_enqueue, .dequeue = cbs_dequeue, -- cgit v1.2.3-59-g8ed1b