[Intel-wired-lan] [next-queue PATCH v6 4/5] net/sched: Add support for HW offloading for CBS
Vinicius Costa Gomes
vinicius.gomes at intel.com
Thu Oct 12 00:54:48 UTC 2017
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 <vinicius.gomes at intel.com>
---
include/linux/netdevice.h | 1 +
include/net/pkt_sched.h | 9 ++++
net/sched/sch_cbs.c | 104 ++++++++++++++++++++++++++++++++++++++++------
3 files changed, 102 insertions(+), 12 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 31bb3010c69b..1f6c44ef5b21 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -775,6 +775,7 @@ enum tc_setup_type {
TC_SETUP_CLSFLOWER,
TC_SETUP_CLSMATCHALL,
TC_SETUP_CLSBPF,
+ 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 259bc191ba59..7c597b050b36 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -146,4 +146,13 @@ static inline bool is_classid_clsact_egress(u32 classid)
TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_EGRESS);
}
+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 29de3e2bc33f..610a72529b72 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -68,6 +68,8 @@
#define BYTES_PER_KBIT (1000 / 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);
@@ -178,6 +185,11 @@ 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);
@@ -189,14 +201,66 @@ 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);
@@ -208,23 +272,30 @@ 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;
q->sendslope = qopt->sendslope;
+ q->offload = qopt->offload;
return 0;
}
@@ -232,10 +303,16 @@ 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);
@@ -244,8 +321,11 @@ 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)
@@ -262,7 +342,7 @@ static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb)
opt.locredit = q->locredit;
opt.sendslope = q->sendslope;
opt.idleslope = q->idleslope;
- opt.offload = 0;
+ opt.offload = q->offload;
if (nla_put(skb, TCA_CBS_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
--
2.14.2
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