// SPDX-License-Identifier: GPL-2.0-only /* * net/sched/sch_mq.c Classful multiqueue dummy scheduler * * Copyright (c) 2009 Patrick McHardy <kaber@trash.net> */ #include <linux/types.h> #include <linux/slab.h> #include <linux/kernel.h> #include <linux/export.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <net/netlink.h> #include <net/pkt_cls.h> #include <net/pkt_sched.h> #include <net/sch_generic.h> struct mq_sched { struct Qdisc **qdiscs; }; static int mq_offload(struct Qdisc *sch, enum tc_mq_command cmd) { struct net_device *dev = qdisc_dev(sch); struct tc_mq_qopt_offload opt = { .command = cmd, .handle = sch->handle, }; if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) return -EOPNOTSUPP; return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_MQ, &opt); } static int mq_offload_stats(struct Qdisc *sch) { struct tc_mq_qopt_offload opt = { .command = TC_MQ_STATS, .handle = sch->handle, .stats = { .bstats = &sch->bstats, .qstats = &sch->qstats, }, }; return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_MQ, &opt); } static void mq_destroy(struct Qdisc *sch) { struct net_device *dev = qdisc_dev(sch); struct mq_sched *priv = qdisc_priv(sch); unsigned int ntx; mq_offload(sch, TC_MQ_DESTROY); if (!priv->qdiscs) return; for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++) qdisc_put(priv->qdiscs[ntx]); kfree(priv->qdiscs); } static int mq_init(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct net_device *dev = qdisc_dev(sch); struct mq_sched *priv = qdisc_priv(sch); struct netdev_queue *dev_queue; struct Qdisc *qdisc; unsigned int ntx; if (sch->parent != TC_H_ROOT) return -EOPNOTSUPP; if (!netif_is_multiqueue(dev)) return -EOPNOTSUPP; /* pre-allocate qdiscs, attachment can't fail */ priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), GFP_KERNEL); if (!priv->qdiscs) return -ENOMEM; for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { dev_queue = netdev_get_tx_queue(dev, ntx); qdisc = qdisc_create_dflt(dev_queue, get_default_qdisc_ops(dev, ntx), TC_H_MAKE(TC_H_MAJ(sch->handle), TC_H_MIN(ntx + 1)), extack); if (!qdisc) return -ENOMEM; priv->qdiscs[ntx] = qdisc; qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; } sch->flags |= TCQ_F_MQROOT; mq_offload(sch, TC_MQ_CREATE); return 0; } static void mq_attach(struct Qdisc *sch) { struct net_device *dev = qdisc_dev(sch); struct mq_sched *priv = qdisc_priv(sch); struct Qdisc *qdisc, *old; unsigned int ntx; for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { qdisc = priv->qdiscs[ntx]; old = dev_graft_qdisc(qdisc->dev_queue, qdisc); if (old) qdisc_put(old); #ifdef CONFIG_NET_SCHED if (ntx < dev->real_num_tx_queues) qdisc_hash_add(qdisc, false); #endif } kfree(priv->qdiscs); priv->qdiscs = NULL; } static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) { struct net_device *dev = qdisc_dev(sch); struct Qdisc *qdisc; unsigned int ntx; sch->q.qlen = 0; gnet_stats_basic_sync_init(&sch->bstats); memset(&sch->qstats, 0, sizeof(sch->qstats)); /* MQ supports lockless qdiscs. However, statistics accounting needs * to account for all, none, or a mix of locked and unlocked child * qdiscs. Percpu stats are added to counters in-band and locking * qdisc totals are added at end. */ for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); spin_lock_bh(qdisc_lock(qdisc)); gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, &qdisc->bstats, false); gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats, &qdisc->qstats); sch->q.qlen += qdisc_qlen(qdisc); spin_unlock_bh(qdisc_lock(qdisc)); } return mq_offload_stats(sch); } static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) { struct net_device *dev = qdisc_dev(sch); unsigned long ntx = cl - 1; if (ntx >= dev->num_tx_queues) return NULL; return netdev_get_tx_queue(dev, ntx); } static struct netdev_queue *mq_select_queue(struct Qdisc *sch, struct tcmsg *tcm) { return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent)); } static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, struct Qdisc **old, struct netlink_ext_ack *extack) { struct netdev_queue *dev_queue = mq_queue_get(sch, cl); struct tc_mq_qopt_offload graft_offload; struct net_device *dev = qdisc_dev(sch); if (dev->flags & IFF_UP) dev_deactivate(dev); *old = dev_graft_qdisc(dev_queue, new); if (new) new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; if (dev->flags & IFF_UP) dev_activate(dev); graft_offload.handle = sch->handle; graft_offload.graft_params.queue = cl - 1; graft_offload.graft_params.child_handle = new ? new->handle : 0; graft_offload.command = TC_MQ_GRAFT; qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old, TC_SETUP_QDISC_MQ, &graft_offload, extack); return 0; } static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) { struct netdev_queue *dev_queue = mq_queue_get(sch, cl); return rtnl_dereference(dev_queue->qdisc_sleeping); } static unsigned long mq_find(struct Qdisc *sch, u32 classid) { unsigned int ntx = TC_H_MIN(classid); if (!mq_queue_get(sch, ntx)) return 0; return ntx; } static int mq_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, struct tcmsg *tcm) { struct netdev_queue *dev_queue = mq_queue_get(sch, cl); tcm->tcm_parent = TC_H_ROOT; tcm->tcm_handle |= TC_H_MIN(cl); tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle; return 0; } static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, struct gnet_dump *d) { struct netdev_queue *dev_queue = mq_queue_get(sch, cl); sch = rtnl_dereference(dev_queue->qdisc_sleeping); if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 || qdisc_qstats_copy(d, sch) < 0) return -1; return 0; } static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) { struct net_device *dev = qdisc_dev(sch); unsigned int ntx; if (arg->stop) return; arg->count = arg->skip; for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { if (!tc_qdisc_stats_dump(sch, ntx + 1, arg)) break; } } static const struct Qdisc_class_ops mq_class_ops = { .select_queue = mq_select_queue, .graft = mq_graft, .leaf = mq_leaf, .find = mq_find, .walk = mq_walk, .dump = mq_dump_class, .dump_stats = mq_dump_class_stats, }; struct Qdisc_ops mq_qdisc_ops __read_mostly = { .cl_ops = &mq_class_ops, .id = "mq", .priv_size = sizeof(struct mq_sched), .init = mq_init, .destroy = mq_destroy, .attach = mq_attach, .change_real_num_tx = mq_change_real_num_tx, .dump = mq_dump, .owner = THIS_MODULE, };