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 = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 86 GFP_KERNEL); 87 if (!priv->qdiscs) 88 return -ENOMEM; 89 90 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 91 dev_queue = netdev_get_tx_queue(dev, ntx); 92 qdisc = qdisc_create_dflt(dev_queue, 93 qdisc_ops ?: get_default_qdisc_ops(dev, ntx), 94 TC_H_MAKE(TC_H_MAJ(sch->handle), 95 TC_H_MIN(ntx + 1)), 96 extack); 97 if (!qdisc) 98 return -ENOMEM; 99 priv->qdiscs[ntx] = qdisc; 100 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 101 } 102 103 sch->flags |= TCQ_F_MQROOT; 104 return 0; 105 } 106 EXPORT_SYMBOL_NS_GPL(mq_init_common, "NET_SCHED_INTERNAL"); 107 108 static int mq_init(struct Qdisc *sch, struct nlattr *opt, 109 struct netlink_ext_ack *extack) 110 { 111 int ret; 112 113 ret = mq_init_common(sch, opt, extack, NULL); 114 if (ret) 115 return ret; 116 117 mq_offload(sch, TC_MQ_CREATE); 118 return 0; 119 } 120 121 void mq_attach(struct Qdisc *sch) 122 { 123 struct net_device *dev = qdisc_dev(sch); 124 struct mq_sched *priv = qdisc_priv(sch); 125 struct Qdisc *qdisc, *old; 126 unsigned int ntx; 127 128 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 129 qdisc = priv->qdiscs[ntx]; 130 old = dev_graft_qdisc(qdisc->dev_queue, qdisc); 131 if (old) 132 qdisc_put(old); 133 #ifdef CONFIG_NET_SCHED 134 if (ntx < dev->real_num_tx_queues) 135 qdisc_hash_add(qdisc, false); 136 #endif 137 138 } 139 kfree(priv->qdiscs); 140 priv->qdiscs = NULL; 141 } 142 EXPORT_SYMBOL_NS_GPL(mq_attach, "NET_SCHED_INTERNAL"); 143 144 void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb) 145 { 146 struct net_device *dev = qdisc_dev(sch); 147 struct Qdisc *qdisc; 148 unsigned int ntx; 149 150 sch->q.qlen = 0; 151 gnet_stats_basic_sync_init(&sch->bstats); 152 memset(&sch->qstats, 0, sizeof(sch->qstats)); 153 154 /* MQ supports lockless qdiscs. However, statistics accounting needs 155 * to account for all, none, or a mix of locked and unlocked child 156 * qdiscs. Percpu stats are added to counters in-band and locking 157 * qdisc totals are added at end. 158 */ 159 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 160 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); 161 spin_lock_bh(qdisc_lock(qdisc)); 162 163 gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, 164 &qdisc->bstats, false); 165 gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats, 166 &qdisc->qstats); 167 sch->q.qlen += qdisc_qlen(qdisc); 168 169 spin_unlock_bh(qdisc_lock(qdisc)); 170 } 171 } 172 EXPORT_SYMBOL_NS_GPL(mq_dump_common, "NET_SCHED_INTERNAL"); 173 174 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) 175 { 176 mq_dump_common(sch, skb); 177 return mq_offload_stats(sch); 178 } 179 180 static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 181 { 182 struct net_device *dev = qdisc_dev(sch); 183 unsigned long ntx = cl - 1; 184 185 if (ntx >= dev->num_tx_queues) 186 return NULL; 187 return netdev_get_tx_queue(dev, ntx); 188 } 189 190 struct netdev_queue *mq_select_queue(struct Qdisc *sch, 191 struct tcmsg *tcm) 192 { 193 return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent)); 194 } 195 EXPORT_SYMBOL_NS_GPL(mq_select_queue, "NET_SCHED_INTERNAL"); 196 197 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 198 struct Qdisc **old, struct netlink_ext_ack *extack) 199 { 200 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 201 struct tc_mq_qopt_offload graft_offload; 202 struct net_device *dev = qdisc_dev(sch); 203 204 if (dev->flags & IFF_UP) 205 dev_deactivate(dev); 206 207 *old = dev_graft_qdisc(dev_queue, new); 208 if (new) 209 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 210 if (dev->flags & IFF_UP) 211 dev_activate(dev); 212 213 graft_offload.handle = sch->handle; 214 graft_offload.graft_params.queue = cl - 1; 215 graft_offload.graft_params.child_handle = new ? new->handle : 0; 216 graft_offload.command = TC_MQ_GRAFT; 217 218 qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, *old, 219 TC_SETUP_QDISC_MQ, &graft_offload, extack); 220 return 0; 221 } 222 223 struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) 224 { 225 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 226 227 return rtnl_dereference(dev_queue->qdisc_sleeping); 228 } 229 EXPORT_SYMBOL_NS_GPL(mq_leaf, "NET_SCHED_INTERNAL"); 230 231 unsigned long mq_find(struct Qdisc *sch, u32 classid) 232 { 233 unsigned int ntx = TC_H_MIN(classid); 234 235 if (!mq_queue_get(sch, ntx)) 236 return 0; 237 return ntx; 238 } 239 EXPORT_SYMBOL_NS_GPL(mq_find, "NET_SCHED_INTERNAL"); 240 241 int mq_dump_class(struct Qdisc *sch, unsigned long cl, 242 struct sk_buff *skb, struct tcmsg *tcm) 243 { 244 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 245 246 tcm->tcm_parent = TC_H_ROOT; 247 tcm->tcm_handle |= TC_H_MIN(cl); 248 tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle; 249 return 0; 250 } 251 EXPORT_SYMBOL_NS_GPL(mq_dump_class, "NET_SCHED_INTERNAL"); 252 253 int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 254 struct gnet_dump *d) 255 { 256 struct netdev_queue *dev_queue = mq_queue_get(sch, cl); 257 258 sch = rtnl_dereference(dev_queue->qdisc_sleeping); 259 if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 || 260 qdisc_qstats_copy(d, sch) < 0) 261 return -1; 262 return 0; 263 } 264 EXPORT_SYMBOL_NS_GPL(mq_dump_class_stats, "NET_SCHED_INTERNAL"); 265 266 void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 267 { 268 struct net_device *dev = qdisc_dev(sch); 269 unsigned int ntx; 270 271 if (arg->stop) 272 return; 273 274 arg->count = arg->skip; 275 for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) { 276 if (!tc_qdisc_stats_dump(sch, ntx + 1, arg)) 277 break; 278 } 279 } 280 EXPORT_SYMBOL_NS_GPL(mq_walk, "NET_SCHED_INTERNAL"); 281 282 static const struct Qdisc_class_ops mq_class_ops = { 283 .select_queue = mq_select_queue, 284 .graft = mq_graft, 285 .leaf = mq_leaf, 286 .find = mq_find, 287 .walk = mq_walk, 288 .dump = mq_dump_class, 289 .dump_stats = mq_dump_class_stats, 290 }; 291 292 struct Qdisc_ops mq_qdisc_ops __read_mostly = { 293 .cl_ops = &mq_class_ops, 294 .id = "mq", 295 .priv_size = sizeof(struct mq_sched), 296 .init = mq_init, 297 .destroy = mq_destroy, 298 .attach = mq_attach, 299 .change_real_num_tx = mq_change_real_num_tx, 300 .dump = mq_dump, 301 .owner = THIS_MODULE, 302 }; 303