From 585d763af09cc21daf48ecc873604ccdb70f6014 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Mon, 16 Oct 2017 18:01:26 -0700 Subject: net/sched: Introduce Credit Based Shaper (CBS) qdisc This queueing discipline implements the shaper algorithm defined by the 802.1Q-2014 Section 8.6.8.2 and detailed in Annex L. It's primary usage is to apply some bandwidth reservation to user defined traffic classes, which are mapped to different queues via the mqprio qdisc. Only a simple software implementation is added for now. Signed-off-by: Vinicius Costa Gomes Signed-off-by: Jesus Sanchez-Palencia Tested-by: Henrik Austad Signed-off-by: Jeff Kirsher --- include/uapi/linux/pkt_sched.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index e7cc3d3c7421..0e88cc262ca0 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -904,4 +904,23 @@ struct tc_pie_xstats { __u32 maxq; /* maximum queue size */ __u32 ecn_mark; /* packets marked with ecn*/ }; + +/* CBS */ +struct tc_cbs_qopt { + __u8 offload; + __u8 _pad[3]; + __s32 hicredit; + __s32 locredit; + __s32 idleslope; + __s32 sendslope; +}; + +enum { + TCA_CBS_UNSPEC, + TCA_CBS_PARMS, + __TCA_CBS_MAX, +}; + +#define TCA_CBS_MAX (__TCA_CBS_MAX - 1) + #endif -- cgit v1.3-14-g43fede From 3d0bd028ffb4a4915cb64cfa0d2cee1578cc0321 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Mon, 16 Oct 2017 18:01:27 -0700 Subject: net/sched: Add support for HW offloading for CBS This adds support for offloading the CBS algorithm to the controller, if supported. Drivers wanting to support CBS offload must implement the .ndo_setup_tc callback and handle the TC_SETUP_CBS (introduced here) type. Signed-off-by: Vinicius Costa Gomes Tested-by: Henrik Austad Signed-off-by: Jeff Kirsher --- include/linux/netdevice.h | 1 + include/net/pkt_sched.h | 9 ++++ net/sched/sch_cbs.c | 104 ++++++++++++++++++++++++++++++++++++++++------ 3 files changed, 102 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6c7960c8338a..5e02f79b2110 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -776,6 +776,7 @@ enum tc_setup_type { TC_SETUP_CLSMATCHALL, TC_SETUP_CLSBPF, TC_SETUP_BLOCK, + TC_SETUP_CBS, }; /* These structures hold the attributes of xdp state that are being passed diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index b8ecafce4ba1..02f2db26e30c 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -140,4 +140,13 @@ static inline struct net *qdisc_net(struct Qdisc *q) return dev_net(q->dev_queue->dev); } +struct tc_cbs_qopt_offload { + u8 enable; + s32 queue; + s32 hicredit; + s32 locredit; + s32 idleslope; + s32 sendslope; +}; + #endif diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index 0e85133c5653..bdb533b7fb8c 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -68,6 +68,8 @@ #define BYTES_PER_KBIT (1000LL / 8) struct cbs_sched_data { + bool offload; + int queue; s64 port_rate; /* in bytes/s */ s64 last; /* timestamp in ns */ s64 credits; /* in bytes */ @@ -80,6 +82,11 @@ struct cbs_sched_data { struct sk_buff *(*dequeue)(struct Qdisc *sch); }; +static int cbs_enqueue_offload(struct sk_buff *skb, struct Qdisc *sch) +{ + return qdisc_enqueue_tail(skb, sch); +} + static int cbs_enqueue_soft(struct sk_buff *skb, struct Qdisc *sch) { struct cbs_sched_data *q = qdisc_priv(sch); @@ -169,6 +176,11 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) return skb; } +static struct sk_buff *cbs_dequeue_offload(struct Qdisc *sch) +{ + return qdisc_dequeue_head(sch); +} + static struct sk_buff *cbs_dequeue(struct Qdisc *sch) { struct cbs_sched_data *q = qdisc_priv(sch); @@ -180,14 +192,66 @@ static const struct nla_policy cbs_policy[TCA_CBS_MAX + 1] = { [TCA_CBS_PARMS] = { .len = sizeof(struct tc_cbs_qopt) }, }; +static void cbs_disable_offload(struct net_device *dev, + struct cbs_sched_data *q) +{ + struct tc_cbs_qopt_offload cbs = { }; + const struct net_device_ops *ops; + int err; + + if (!q->offload) + return; + + q->enqueue = cbs_enqueue_soft; + q->dequeue = cbs_dequeue_soft; + + ops = dev->netdev_ops; + if (!ops->ndo_setup_tc) + return; + + cbs.queue = q->queue; + cbs.enable = 0; + + err = ops->ndo_setup_tc(dev, TC_SETUP_CBS, &cbs); + if (err < 0) + pr_warn("Couldn't disable CBS offload for queue %d\n", + cbs.queue); +} + +static int cbs_enable_offload(struct net_device *dev, struct cbs_sched_data *q, + const struct tc_cbs_qopt *opt) +{ + const struct net_device_ops *ops = dev->netdev_ops; + struct tc_cbs_qopt_offload cbs = { }; + int err; + + if (!ops->ndo_setup_tc) + return -EOPNOTSUPP; + + cbs.queue = q->queue; + + cbs.enable = 1; + cbs.hicredit = opt->hicredit; + cbs.locredit = opt->locredit; + cbs.idleslope = opt->idleslope; + cbs.sendslope = opt->sendslope; + + err = ops->ndo_setup_tc(dev, TC_SETUP_CBS, &cbs); + if (err < 0) + return err; + + q->enqueue = cbs_enqueue_offload; + q->dequeue = cbs_dequeue_offload; + + return 0; +} + static int cbs_change(struct Qdisc *sch, struct nlattr *opt) { struct cbs_sched_data *q = qdisc_priv(sch); struct net_device *dev = qdisc_dev(sch); struct nlattr *tb[TCA_CBS_MAX + 1]; - struct ethtool_link_ksettings ecmd; struct tc_cbs_qopt *qopt; - s64 link_speed; int err; err = nla_parse_nested(tb, TCA_CBS_MAX, opt, cbs_policy, NULL); @@ -199,23 +263,30 @@ static int cbs_change(struct Qdisc *sch, struct nlattr *opt) qopt = nla_data(tb[TCA_CBS_PARMS]); - if (qopt->offload) - return -EOPNOTSUPP; + if (!qopt->offload) { + struct ethtool_link_ksettings ecmd; + s64 link_speed; - if (!__ethtool_get_link_ksettings(dev, &ecmd)) - link_speed = ecmd.base.speed; - else - link_speed = SPEED_1000; + if (!__ethtool_get_link_ksettings(dev, &ecmd)) + link_speed = ecmd.base.speed; + else + link_speed = SPEED_1000; - q->port_rate = link_speed * 1000 * BYTES_PER_KBIT; + q->port_rate = link_speed * 1000 * BYTES_PER_KBIT; - q->enqueue = cbs_enqueue_soft; - q->dequeue = cbs_dequeue_soft; + cbs_disable_offload(dev, q); + } else { + err = cbs_enable_offload(dev, q, qopt); + if (err < 0) + return err; + } + /* Everything went OK, save the parameters used. */ q->hicredit = qopt->hicredit; q->locredit = qopt->locredit; q->idleslope = qopt->idleslope * BYTES_PER_KBIT; q->sendslope = qopt->sendslope * BYTES_PER_KBIT; + q->offload = qopt->offload; return 0; } @@ -223,10 +294,16 @@ static int cbs_change(struct Qdisc *sch, struct nlattr *opt) static int cbs_init(struct Qdisc *sch, struct nlattr *opt) { struct cbs_sched_data *q = qdisc_priv(sch); + struct net_device *dev = qdisc_dev(sch); if (!opt) return -EINVAL; + q->queue = sch->dev_queue - netdev_get_tx_queue(dev, 0); + + q->enqueue = cbs_enqueue_soft; + q->dequeue = cbs_dequeue_soft; + qdisc_watchdog_init(&q->watchdog, sch); return cbs_change(sch, opt); @@ -235,8 +312,11 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt) static void cbs_destroy(struct Qdisc *sch) { struct cbs_sched_data *q = qdisc_priv(sch); + struct net_device *dev = qdisc_dev(sch); qdisc_watchdog_cancel(&q->watchdog); + + cbs_disable_offload(dev, q); } static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb) @@ -253,7 +333,7 @@ static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb) opt.locredit = q->locredit; opt.sendslope = div64_s64(q->sendslope, BYTES_PER_KBIT); opt.idleslope = div64_s64(q->idleslope, BYTES_PER_KBIT); - opt.offload = 0; + opt.offload = q->offload; if (nla_put(skb, TCA_CBS_PARMS, sizeof(opt), &opt)) goto nla_put_failure; -- cgit v1.3-14-g43fede