1 files changed, 420 insertions, 0 deletions

diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
new file mode 100644
index 000000000..1c6dbcfa8
--- /dev/null
+++ b/net/sched/sch_multiq.c
@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2008, Intel Corporation.
+ *
+ * Author: Alexander Duyck <alexander.h.duyck@intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+struct multiq_sched_data {
+	u16 bands;
+	u16 max_bands;
+	u16 curband;
+	struct tcf_proto __rcu *filter_list;
+	struct tcf_block *block;
+	struct Qdisc **queues;
+};
+
+
+static struct Qdisc *
+multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	u32 band;
+	struct tcf_result res;
+	struct tcf_proto *fl = rcu_dereference_bh(q->filter_list);
+	int err;
+
+	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+	err = tcf_classify(skb, fl, &res, false);
+#ifdef CONFIG_NET_CLS_ACT
+	switch (err) {
+	case TC_ACT_STOLEN:
+	case TC_ACT_QUEUED:
+	case TC_ACT_TRAP:
+		*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+		fallthrough;
+	case TC_ACT_SHOT:
+		return NULL;
+	}
+#endif
+	band = skb_get_queue_mapping(skb);
+
+	if (band >= q->bands)
+		return q->queues[0];
+
+	return q->queues[band];
+}
+
+static int
+multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+	       struct sk_buff **to_free)
+{
+	struct Qdisc *qdisc;
+	int ret;
+
+	qdisc = multiq_classify(skb, sch, &ret);
+#ifdef CONFIG_NET_CLS_ACT
+	if (qdisc == NULL) {
+
+		if (ret & __NET_XMIT_BYPASS)
+			qdisc_qstats_drop(sch);
+		__qdisc_drop(skb, to_free);
+		return ret;
+	}
+#endif
+
+	ret = qdisc_enqueue(skb, qdisc, to_free);
+	if (ret == NET_XMIT_SUCCESS) {
+		sch->q.qlen++;
+		return NET_XMIT_SUCCESS;
+	}
+	if (net_xmit_drop_count(ret))
+		qdisc_qstats_drop(sch);
+	return ret;
+}
+
+static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	struct Qdisc *qdisc;
+	struct sk_buff *skb;
+	int band;
+
+	for (band = 0; band < q->bands; band++) {
+		/* cycle through bands to ensure fairness */
+		q->curband++;
+		if (q->curband >= q->bands)
+			q->curband = 0;
+
+		/* Check that target subqueue is available before
+		 * pulling an skb to avoid head-of-line blocking.
+		 */
+		if (!netif_xmit_stopped(
+		    netdev_get_tx_queue(qdisc_dev(sch), q->curband))) {
+			qdisc = q->queues[q->curband];
+			skb = qdisc->dequeue(qdisc);
+			if (skb) {
+				qdisc_bstats_update(sch, skb);
+				sch->q.qlen--;
+				return skb;
+			}
+		}
+	}
+	return NULL;
+
+}
+
+static struct sk_buff *multiq_peek(struct Qdisc *sch)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	unsigned int curband = q->curband;
+	struct Qdisc *qdisc;
+	struct sk_buff *skb;
+	int band;
+
+	for (band = 0; band < q->bands; band++) {
+		/* cycle through bands to ensure fairness */
+		curband++;
+		if (curband >= q->bands)
+			curband = 0;
+
+		/* Check that target subqueue is available before
+		 * pulling an skb to avoid head-of-line blocking.
+		 */
+		if (!netif_xmit_stopped(
+		    netdev_get_tx_queue(qdisc_dev(sch), curband))) {
+			qdisc = q->queues[curband];
+			skb = qdisc->ops->peek(qdisc);
+			if (skb)
+				return skb;
+		}
+	}
+	return NULL;
+
+}
+
+static void
+multiq_reset(struct Qdisc *sch)
+{
+	u16 band;
+	struct multiq_sched_data *q = qdisc_priv(sch);
+
+	for (band = 0; band < q->bands; band++)
+		qdisc_reset(q->queues[band]);
+	q->curband = 0;
+}
+
+static void
+multiq_destroy(struct Qdisc *sch)
+{
+	int band;
+	struct multiq_sched_data *q = qdisc_priv(sch);
+
+	tcf_block_put(q->block);
+	for (band = 0; band < q->bands; band++)
+		qdisc_put(q->queues[band]);
+
+	kfree(q->queues);
+}
+
+static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
+		       struct netlink_ext_ack *extack)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	struct tc_multiq_qopt *qopt;
+	struct Qdisc **removed;
+	int i, n_removed = 0;
+
+	if (!netif_is_multiqueue(qdisc_dev(sch)))
+		return -EOPNOTSUPP;
+	if (nla_len(opt) < sizeof(*qopt))
+		return -EINVAL;
+
+	qopt = nla_data(opt);
+
+	qopt->bands = qdisc_dev(sch)->real_num_tx_queues;
+
+	removed = kmalloc(sizeof(*removed) * (q->max_bands - q->bands),
+			  GFP_KERNEL);
+	if (!removed)
+		return -ENOMEM;
+
+	sch_tree_lock(sch);
+	q->bands = qopt->bands;
+	for (i = q->bands; i < q->max_bands; i++) {
+		if (q->queues[i] != &noop_qdisc) {
+			struct Qdisc *child = q->queues[i];
+
+			q->queues[i] = &noop_qdisc;
+			qdisc_purge_queue(child);
+			removed[n_removed++] = child;
+		}
+	}
+
+	sch_tree_unlock(sch);
+
+	for (i = 0; i < n_removed; i++)
+		qdisc_put(removed[i]);
+	kfree(removed);
+
+	for (i = 0; i < q->bands; i++) {
+		if (q->queues[i] == &noop_qdisc) {
+			struct Qdisc *child, *old;
+			child = qdisc_create_dflt(sch->dev_queue,
+						  &pfifo_qdisc_ops,
+						  TC_H_MAKE(sch->handle,
+							    i + 1), extack);
+			if (child) {
+				sch_tree_lock(sch);
+				old = q->queues[i];
+				q->queues[i] = child;
+				if (child != &noop_qdisc)
+					qdisc_hash_add(child, true);
+
+				if (old != &noop_qdisc)
+					qdisc_purge_queue(old);
+				sch_tree_unlock(sch);
+				qdisc_put(old);
+			}
+		}
+	}
+	return 0;
+}
+
+static int multiq_init(struct Qdisc *sch, struct nlattr *opt,
+		       struct netlink_ext_ack *extack)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	int i, err;
+
+	q->queues = NULL;
+
+	if (!opt)
+		return -EINVAL;
+
+	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+	if (err)
+		return err;
+
+	q->max_bands = qdisc_dev(sch)->num_tx_queues;
+
+	q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL);
+	if (!q->queues)
+		return -ENOBUFS;
+	for (i = 0; i < q->max_bands; i++)
+		q->queues[i] = &noop_qdisc;
+
+	return multiq_tune(sch, opt, extack);
+}
+
+static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tc_multiq_qopt opt;
+
+	opt.bands = q->bands;
+	opt.max_bands = q->max_bands;
+
+	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+			struct Qdisc **old, struct netlink_ext_ack *extack)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	unsigned long band = arg - 1;
+
+	if (new == NULL)
+		new = &noop_qdisc;
+
+	*old = qdisc_replace(sch, new, &q->queues[band]);
+	return 0;
+}
+
+static struct Qdisc *
+multiq_leaf(struct Qdisc *sch, unsigned long arg)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	unsigned long band = arg - 1;
+
+	return q->queues[band];
+}
+
+static unsigned long multiq_find(struct Qdisc *sch, u32 classid)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	unsigned long band = TC_H_MIN(classid);
+
+	if (band - 1 >= q->bands)
+		return 0;
+	return band;
+}
+
+static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
+				 u32 classid)
+{
+	return multiq_find(sch, classid);
+}
+
+
+static void multiq_unbind(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
+			     struct sk_buff *skb, struct tcmsg *tcm)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+
+	tcm->tcm_handle |= TC_H_MIN(cl);
+	tcm->tcm_info = q->queues[cl - 1]->handle;
+	return 0;
+}
+
+static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+				 struct gnet_dump *d)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	struct Qdisc *cl_q;
+
+	cl_q = q->queues[cl - 1];
+	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
+				  d, cl_q->cpu_bstats, &cl_q->bstats) < 0 ||
+	    qdisc_qstats_copy(d, cl_q) < 0)
+		return -1;
+
+	return 0;
+}
+
+static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+	int band;
+
+	if (arg->stop)
+		return;
+
+	for (band = 0; band < q->bands; band++) {
+		if (arg->count < arg->skip) {
+			arg->count++;
+			continue;
+		}
+		if (arg->fn(sch, band + 1, arg) < 0) {
+			arg->stop = 1;
+			break;
+		}
+		arg->count++;
+	}
+}
+
+static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl,
+					  struct netlink_ext_ack *extack)
+{
+	struct multiq_sched_data *q = qdisc_priv(sch);
+
+	if (cl)
+		return NULL;
+	return q->block;
+}
+
+static const struct Qdisc_class_ops multiq_class_ops = {
+	.graft		=	multiq_graft,
+	.leaf		=	multiq_leaf,
+	.find		=	multiq_find,
+	.walk		=	multiq_walk,
+	.tcf_block	=	multiq_tcf_block,
+	.bind_tcf	=	multiq_bind,
+	.unbind_tcf	=	multiq_unbind,
+	.dump		=	multiq_dump_class,
+	.dump_stats	=	multiq_dump_class_stats,
+};
+
+static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
+	.next		=	NULL,
+	.cl_ops		=	&multiq_class_ops,
+	.id		=	"multiq",
+	.priv_size	=	sizeof(struct multiq_sched_data),
+	.enqueue	=	multiq_enqueue,
+	.dequeue	=	multiq_dequeue,
+	.peek		=	multiq_peek,
+	.init		=	multiq_init,
+	.reset		=	multiq_reset,
+	.destroy	=	multiq_destroy,
+	.change		=	multiq_tune,
+	.dump		=	multiq_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init multiq_module_init(void)
+{
+	return register_qdisc(&multiq_qdisc_ops);
+}
+
+static void __exit multiq_module_exit(void)
+{
+	unregister_qdisc(&multiq_qdisc_ops);
+}
+
+module_init(multiq_module_init)
+module_exit(multiq_module_exit)
+
+MODULE_LICENSE("GPL");