1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * net/sched/sch_mq.c Classful multiqueue dummy scheduler 4 * 5 * Copyright (c) 2009 Patrick McHardy <kaber@trash.net> 6 */ 7 8 #include <linux/types.h> 9 #include <linux/slab.h> 10 #include <linux/kernel.h> 11 #include <linux/export.h> 12 #include <linux/string.h> 13 #include <linux/errno.h> 14 #include <linux/skbuff.h> 15 #include <net/netlink.h> 16 #include <net/pkt_cls.h> 17 #include <net/pkt_sched.h> 18 #include <net/sch_priv.h> 19 20 static int mq_offload(struct Qdisc *sch, enum tc_mq_command cmd) 21 { 22 struct net_device *dev = qdisc_dev(sch); 23 struct tc_mq_qopt_offload opt = { 24 .command = cmd, 25 .handle = sch->handle, 26 }; 27 28 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 29 return -EOPNOTSUPP; 30 31 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_MQ, &opt); 32 } 33 34 static int mq_offload_stats(struct Qdisc *sch) 35 { 36 struct tc_mq_qopt_offload opt = { 37 .command = TC_MQ_STATS, 38 .handle = sch->handle, 39 .stats = { 40 .bstats = &sch->bstats, 41 .qstats = &sch->qstats, 42 }, 43 }; 44 45 return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_MQ, &opt); 46 } 47 48 void mq_destroy_common(struct Qdisc *sch) 49 { 50 struct net_device *dev = qdisc_dev(sch); 51 struct mq_sched *priv = qdisc_priv(sch); 52 unsigned int ntx; 53 54 if (!priv->qdiscs) 55 return; 56 for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++) 57 qdisc_put(priv->qdiscs[ntx]); 58 kfree(priv->qdiscs); 59 } 60 EXPORT_SYMBOL_NS_GPL(mq_destroy_common, "NET_SCHED_INTERNAL"); 61 62 static void mq_destroy(struct Qdisc *sch) 63 { 64 mq_offload(sch, TC_MQ_DESTROY); 65 mq_destroy_common(sch); 66 } 67 68 int mq_init_common(struct Qdisc *sch, struct nlattr *opt, 69 struct netlink_ext_ack *extack, 70 const struct Qdisc_ops *qdisc_ops) 71 { 72 struct net_device *dev = qdisc_dev(sch); 73 struct mq_sched *priv = qdisc_priv(sch); 74 struct netdev_queue *dev_queue; 75 struct Qdisc *qdisc; 76 unsigned int ntx; 77 78 if (sch->parent != TC_H_ROOT) 79 return -EOPNOTSUPP; 80 81 if (!netif_is_multiqueue(dev)) 82 return -EOPNOTSUPP; 83 84 /* pre-allocate qdiscs, attachment can't fail */ 85 priv->qdiscs = kzalloc_objs(priv->qdiscs[0], dev->num_tx_queues); 86 if (!priv->qdiscs) 87 return -ENOMEM; 88 89 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 90 dev_queue = netdev_get_tx_queue(dev, ntx); 91 qdisc = qdisc_create_dflt(dev_queue, 92 qdisc_ops ?: get_default_qdisc_ops(dev, ntx), 93 TC_H_MAKE(TC_H_MAJ(sch->handle), 94 TC_H_MIN(ntx + 1)), 95 extack); 96 if (!qdisc) 97 return -ENOMEM; 98 priv->qdiscs[ntx] = qdisc; 99 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 100 } 101 102 sch->flags |= TCQ_F_MQROOT; 103 return 0; 104 } 105 EXPORT_SYMBOL_NS_GPL(mq_init_common, "NET_SCHED_INTERNAL"); 106 107 static int mq_init(struct Qdisc *sch, struct nlattr *opt, 108 struct netlink_ext_ack *extack) 109 { 110 int ret; 111 112 ret = mq_init_common(sch, opt, extack, NULL); 113 if (ret) 114 return ret; 115 116 mq_offload(sch, TC_MQ_CREATE); 117 return 0; 118 } 119 120 void mq_attach(struct Qdisc *sch) 121 { 122 struct net_device *dev = qdisc_dev(sch); 123 struct mq_sched *priv = qdisc_priv(sch); 124 struct Qdisc *qdisc, *old; 125 unsigned int ntx; 126 127 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 128 qdisc = priv->qdiscs[ntx]; 129 old = dev_graft_qdisc(qdisc->dev_queue, qdisc); 130 if (old) 131 qdisc_put(old); 132 #ifdef CONFIG_NET_SCHED 133 if (ntx < dev->real_num_tx_queues) 134 qdisc_hash_add(qdisc, false); 135 #endif 136 137 } 138 kfree(priv->qdiscs); 139 priv->qdiscs = NULL; 140 } 141 EXPORT_SYMBOL_NS_GPL(mq_attach, "NET_SCHED_INTERNAL"); 142 143 void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb) 144 { 145 struct net_device *dev = qdisc_dev(sch); 146 struct Qdisc *qdisc; 147 unsigned int ntx; 148 149 sch->q.qlen = 0; 150 gnet_stats_basic_sync_init(&sch->bstats); 151 memset(&sch->qstats, 0, sizeof(sch->qstats)); 152 153 /* MQ supports lockless qdiscs. However, statistics accounting needs 154 * to account for all, none, or a mix of locked and unlocked child 155 * qdiscs. Percpu stats are added to counters in-band and locking 156 * qdisc totals are added at end. 157 */ 158 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 159 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); 160 spin_lock_bh(qdisc_lock(qdisc)); 161 162 gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, 163 &qdisc->bstats, false); 164 gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats, 165 &qdisc->qstats); 166 sch->q.qlen += qdisc_qlen(qdisc); 167 168 spin_unlock_bh(qdisc_lock(qdisc)); 169 } 170 } 171 EXPORT_SYMBOL_NS_GPL(mq_dump_common, "NET_SCHED_INTERNAL"); 172 173 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) 174 { 175 mq_dump_common(sch, skb); 176 return mq_offload_stats(sch); 177 } 178 179 static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 180 { 181 struct net_device *dev = qdisc_dev(sch); 182 unsigned long ntx = cl - 1; 183 184 if (ntx >= dev->num_tx_queues) 185 return NULL; 186 return netdev_get_tx_queue(dev, ntx); 187 } 188 189 struct netdev_queue *mq_select_queue(struct Qdisc *sch, 190 struct tcmsg *tcm) 191 { 192 return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent)); 193 } 194 EXPORT_SYMBOL_NS_GPL(mq_select_queue, "NET_SCHED_INTERNAL"); 195 196 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 197 struct Qdisc **old, struct netlink_ext_ack *extack) 198 { 199 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 200 struct tc_mq_qopt_offload graft_offload; 201 struct net_device *dev = qdisc_dev(sch); 202 203 if (dev->flags & IFF_UP) 204 dev_deactivate(dev); 205 206 *old = dev_graft_qdisc(dev_queue, new); 207 if (new) 208 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 209 if (dev->flags & IFF_UP) 210 dev_activate(dev); 211 212 graft_offload.handle = sch->handle; 213 graft_offload.graft_params.queue = cl - 1; 214 graft_offload.graft_params.child_handle = new ? new->handle : 0; 215 graft_offload.command = TC_MQ_GRAFT; 216 217 qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old, 218 TC_SETUP_QDISC_MQ, &graft_offload, extack); 219 return 0; 220 } 221 222 struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) 223 { 224 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 225 226 return rtnl_dereference(dev_queue->qdisc_sleeping); 227 } 228 EXPORT_SYMBOL_NS_GPL(mq_leaf, "NET_SCHED_INTERNAL"); 229 230 unsigned long mq_find(struct Qdisc *sch, u32 classid) 231 { 232 unsigned int ntx = TC_H_MIN(classid); 233 234 if (!mq_queue_get(sch, ntx)) 235 return 0; 236 return ntx; 237 } 238 EXPORT_SYMBOL_NS_GPL(mq_find, "NET_SCHED_INTERNAL"); 239 240 int mq_dump_class(struct Qdisc *sch, unsigned long cl, 241 struct sk_buff *skb, struct tcmsg *tcm) 242 { 243 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 244 245 tcm->tcm_parent = TC_H_ROOT; 246 tcm->tcm_handle |= TC_H_MIN(cl); 247 tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle; 248 return 0; 249 } 250 EXPORT_SYMBOL_NS_GPL(mq_dump_class, "NET_SCHED_INTERNAL"); 251 252 int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 253 struct gnet_dump *d) 254 { 255 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 256 257 sch = rtnl_dereference(dev_queue->qdisc_sleeping); 258 if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 || 259 qdisc_qstats_copy(d, sch) < 0) 260 return -1; 261 return 0; 262 } 263 EXPORT_SYMBOL_NS_GPL(mq_dump_class_stats, "NET_SCHED_INTERNAL"); 264 265 void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 266 { 267 struct net_device *dev = qdisc_dev(sch); 268 unsigned int ntx; 269 270 if (arg->stop) 271 return; 272 273 arg->count = arg->skip; 274 for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { 275 if (!tc_qdisc_stats_dump(sch, ntx + 1, arg)) 276 break; 277 } 278 } 279 EXPORT_SYMBOL_NS_GPL(mq_walk, "NET_SCHED_INTERNAL"); 280 281 static const struct Qdisc_class_ops mq_class_ops = { 282 .select_queue = mq_select_queue, 283 .graft = mq_graft, 284 .leaf = mq_leaf, 285 .find = mq_find, 286 .walk = mq_walk, 287 .dump = mq_dump_class, 288 .dump_stats = mq_dump_class_stats, 289 }; 290 291 struct Qdisc_ops mq_qdisc_ops __read_mostly = { 292 .cl_ops = &mq_class_ops, 293 .id = "mq", 294 .priv_size = sizeof(struct mq_sched), 295 .init = mq_init, 296 .destroy = mq_destroy, 297 .attach = mq_attach, 298 .change_real_num_tx = mq_change_real_num_tx, 299 .dump = mq_dump, 300 .owner = THIS_MODULE, 301 }; 302