1 /* 2 * net/sched/sch_mqprio.c 3 * 4 * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 */ 10 11 #include <linux/types.h> 12 #include <linux/slab.h> 13 #include <linux/kernel.h> 14 #include <linux/string.h> 15 #include <linux/errno.h> 16 #include <linux/skbuff.h> 17 #include <linux/module.h> 18 #include <net/netlink.h> 19 #include <net/pkt_sched.h> 20 #include <net/sch_generic.h> 21 22 struct mqprio_sched { 23 struct Qdisc **qdiscs; 24 int hw_offload; 25 }; 26 27 static void mqprio_destroy(struct Qdisc *sch) 28 { 29 struct net_device *dev = qdisc_dev(sch); 30 struct mqprio_sched *priv = qdisc_priv(sch); 31 unsigned int ntx; 32 33 if (priv->qdiscs) { 34 for (ntx = 0; 35 ntx < dev->num_tx_queues && priv->qdiscs[ntx]; 36 ntx++) 37 qdisc_destroy(priv->qdiscs[ntx]); 38 kfree(priv->qdiscs); 39 } 40 41 if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc) { 42 struct tc_mqprio_qopt offload = { 0 }; 43 struct tc_to_netdev tc = { .type = TC_SETUP_MQPRIO, 44 { .mqprio = &offload } }; 45 46 dev->netdev_ops->ndo_setup_tc(dev, sch->handle, 0, &tc); 47 } else { 48 netdev_set_num_tc(dev, 0); 49 } 50 } 51 52 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt) 53 { 54 int i, j; 55 56 /* Verify num_tc is not out of max range */ 57 if (qopt->num_tc > TC_MAX_QUEUE) 58 return -EINVAL; 59 60 /* Verify priority mapping uses valid tcs */ 61 for (i = 0; i < TC_BITMASK + 1; i++) { 62 if (qopt->prio_tc_map[i] >= qopt->num_tc) 63 return -EINVAL; 64 } 65 66 /* Limit qopt->hw to maximum supported offload value. Drivers have 67 * the option of overriding this later if they don't support the a 68 * given offload type. 69 */ 70 if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX) 71 qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX; 72 73 /* If hardware offload is requested we will leave it to the device 74 * to either populate the queue counts itself or to validate the 75 * provided queue counts. If ndo_setup_tc is not present then 76 * hardware doesn't support offload and we should return an error. 77 */ 78 if (qopt->hw) 79 return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL; 80 81 for (i = 0; i < qopt->num_tc; i++) { 82 unsigned int last = qopt->offset[i] + qopt->count[i]; 83 84 /* Verify the queue count is in tx range being equal to the 85 * real_num_tx_queues indicates the last queue is in use. 86 */ 87 if (qopt->offset[i] >= dev->real_num_tx_queues || 88 !qopt->count[i] || 89 last > dev->real_num_tx_queues) 90 return -EINVAL; 91 92 /* Verify that the offset and counts do not overlap */ 93 for (j = i + 1; j < qopt->num_tc; j++) { 94 if (last > qopt->offset[j]) 95 return -EINVAL; 96 } 97 } 98 99 return 0; 100 } 101 102 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt) 103 { 104 struct net_device *dev = qdisc_dev(sch); 105 struct mqprio_sched *priv = qdisc_priv(sch); 106 struct netdev_queue *dev_queue; 107 struct Qdisc *qdisc; 108 int i, err = -EOPNOTSUPP; 109 struct tc_mqprio_qopt *qopt = NULL; 110 111 BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE); 112 BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK); 113 114 if (sch->parent != TC_H_ROOT) 115 return -EOPNOTSUPP; 116 117 if (!netif_is_multiqueue(dev)) 118 return -EOPNOTSUPP; 119 120 if (!opt || nla_len(opt) < sizeof(*qopt)) 121 return -EINVAL; 122 123 qopt = nla_data(opt); 124 if (mqprio_parse_opt(dev, qopt)) 125 return -EINVAL; 126 127 /* pre-allocate qdisc, attachment can't fail */ 128 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 129 GFP_KERNEL); 130 if (!priv->qdiscs) 131 return -ENOMEM; 132 133 for (i = 0; i < dev->num_tx_queues; i++) { 134 dev_queue = netdev_get_tx_queue(dev, i); 135 qdisc = qdisc_create_dflt(dev_queue, 136 get_default_qdisc_ops(dev, i), 137 TC_H_MAKE(TC_H_MAJ(sch->handle), 138 TC_H_MIN(i + 1))); 139 if (!qdisc) 140 return -ENOMEM; 141 142 priv->qdiscs[i] = qdisc; 143 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 144 } 145 146 /* If the mqprio options indicate that hardware should own 147 * the queue mapping then run ndo_setup_tc otherwise use the 148 * supplied and verified mapping 149 */ 150 if (qopt->hw) { 151 struct tc_mqprio_qopt offload = *qopt; 152 struct tc_to_netdev tc = { .type = TC_SETUP_MQPRIO, 153 { .mqprio = &offload } }; 154 155 err = dev->netdev_ops->ndo_setup_tc(dev, sch->handle, 0, &tc); 156 if (err) 157 return err; 158 159 priv->hw_offload = offload.hw; 160 } else { 161 netdev_set_num_tc(dev, qopt->num_tc); 162 for (i = 0; i < qopt->num_tc; i++) 163 netdev_set_tc_queue(dev, i, 164 qopt->count[i], qopt->offset[i]); 165 } 166 167 /* Always use supplied priority mappings */ 168 for (i = 0; i < TC_BITMASK + 1; i++) 169 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]); 170 171 sch->flags |= TCQ_F_MQROOT; 172 return 0; 173 } 174 175 static void mqprio_attach(struct Qdisc *sch) 176 { 177 struct net_device *dev = qdisc_dev(sch); 178 struct mqprio_sched *priv = qdisc_priv(sch); 179 struct Qdisc *qdisc, *old; 180 unsigned int ntx; 181 182 /* Attach underlying qdisc */ 183 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 184 qdisc = priv->qdiscs[ntx]; 185 old = dev_graft_qdisc(qdisc->dev_queue, qdisc); 186 if (old) 187 qdisc_destroy(old); 188 if (ntx < dev->real_num_tx_queues) 189 qdisc_hash_add(qdisc, false); 190 } 191 kfree(priv->qdiscs); 192 priv->qdiscs = NULL; 193 } 194 195 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch, 196 unsigned long cl) 197 { 198 struct net_device *dev = qdisc_dev(sch); 199 unsigned long ntx = cl - 1 - netdev_get_num_tc(dev); 200 201 if (ntx >= dev->num_tx_queues) 202 return NULL; 203 return netdev_get_tx_queue(dev, ntx); 204 } 205 206 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 207 struct Qdisc **old) 208 { 209 struct net_device *dev = qdisc_dev(sch); 210 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 211 212 if (!dev_queue) 213 return -EINVAL; 214 215 if (dev->flags & IFF_UP) 216 dev_deactivate(dev); 217 218 *old = dev_graft_qdisc(dev_queue, new); 219 220 if (new) 221 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; 222 223 if (dev->flags & IFF_UP) 224 dev_activate(dev); 225 226 return 0; 227 } 228 229 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) 230 { 231 struct net_device *dev = qdisc_dev(sch); 232 struct mqprio_sched *priv = qdisc_priv(sch); 233 unsigned char *b = skb_tail_pointer(skb); 234 struct tc_mqprio_qopt opt = { 0 }; 235 struct Qdisc *qdisc; 236 unsigned int i; 237 238 sch->q.qlen = 0; 239 memset(&sch->bstats, 0, sizeof(sch->bstats)); 240 memset(&sch->qstats, 0, sizeof(sch->qstats)); 241 242 for (i = 0; i < dev->num_tx_queues; i++) { 243 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 244 spin_lock_bh(qdisc_lock(qdisc)); 245 sch->q.qlen += qdisc->q.qlen; 246 sch->bstats.bytes += qdisc->bstats.bytes; 247 sch->bstats.packets += qdisc->bstats.packets; 248 sch->qstats.backlog += qdisc->qstats.backlog; 249 sch->qstats.drops += qdisc->qstats.drops; 250 sch->qstats.requeues += qdisc->qstats.requeues; 251 sch->qstats.overlimits += qdisc->qstats.overlimits; 252 spin_unlock_bh(qdisc_lock(qdisc)); 253 } 254 255 opt.num_tc = netdev_get_num_tc(dev); 256 memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map)); 257 opt.hw = priv->hw_offload; 258 259 for (i = 0; i < netdev_get_num_tc(dev); i++) { 260 opt.count[i] = dev->tc_to_txq[i].count; 261 opt.offset[i] = dev->tc_to_txq[i].offset; 262 } 263 264 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 265 goto nla_put_failure; 266 267 return skb->len; 268 nla_put_failure: 269 nlmsg_trim(skb, b); 270 return -1; 271 } 272 273 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl) 274 { 275 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 276 277 if (!dev_queue) 278 return NULL; 279 280 return dev_queue->qdisc_sleeping; 281 } 282 283 static unsigned long mqprio_get(struct Qdisc *sch, u32 classid) 284 { 285 struct net_device *dev = qdisc_dev(sch); 286 unsigned int ntx = TC_H_MIN(classid); 287 288 if (ntx > dev->num_tx_queues + netdev_get_num_tc(dev)) 289 return 0; 290 return ntx; 291 } 292 293 static void mqprio_put(struct Qdisc *sch, unsigned long cl) 294 { 295 } 296 297 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl, 298 struct sk_buff *skb, struct tcmsg *tcm) 299 { 300 struct net_device *dev = qdisc_dev(sch); 301 302 if (cl <= netdev_get_num_tc(dev)) { 303 tcm->tcm_parent = TC_H_ROOT; 304 tcm->tcm_info = 0; 305 } else { 306 int i; 307 struct netdev_queue *dev_queue; 308 309 dev_queue = mqprio_queue_get(sch, cl); 310 tcm->tcm_parent = 0; 311 for (i = 0; i < netdev_get_num_tc(dev); i++) { 312 struct netdev_tc_txq tc = dev->tc_to_txq[i]; 313 int q_idx = cl - netdev_get_num_tc(dev); 314 315 if (q_idx > tc.offset && 316 q_idx <= tc.offset + tc.count) { 317 tcm->tcm_parent = 318 TC_H_MAKE(TC_H_MAJ(sch->handle), 319 TC_H_MIN(i + 1)); 320 break; 321 } 322 } 323 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 324 } 325 tcm->tcm_handle |= TC_H_MIN(cl); 326 return 0; 327 } 328 329 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 330 struct gnet_dump *d) 331 __releases(d->lock) 332 __acquires(d->lock) 333 { 334 struct net_device *dev = qdisc_dev(sch); 335 336 if (cl <= netdev_get_num_tc(dev)) { 337 int i; 338 __u32 qlen = 0; 339 struct Qdisc *qdisc; 340 struct gnet_stats_queue qstats = {0}; 341 struct gnet_stats_basic_packed bstats = {0}; 342 struct netdev_tc_txq tc = dev->tc_to_txq[cl - 1]; 343 344 /* Drop lock here it will be reclaimed before touching 345 * statistics this is required because the d->lock we 346 * hold here is the look on dev_queue->qdisc_sleeping 347 * also acquired below. 348 */ 349 if (d->lock) 350 spin_unlock_bh(d->lock); 351 352 for (i = tc.offset; i < tc.offset + tc.count; i++) { 353 struct netdev_queue *q = netdev_get_tx_queue(dev, i); 354 355 qdisc = rtnl_dereference(q->qdisc); 356 spin_lock_bh(qdisc_lock(qdisc)); 357 qlen += qdisc->q.qlen; 358 bstats.bytes += qdisc->bstats.bytes; 359 bstats.packets += qdisc->bstats.packets; 360 qstats.backlog += qdisc->qstats.backlog; 361 qstats.drops += qdisc->qstats.drops; 362 qstats.requeues += qdisc->qstats.requeues; 363 qstats.overlimits += qdisc->qstats.overlimits; 364 spin_unlock_bh(qdisc_lock(qdisc)); 365 } 366 /* Reclaim root sleeping lock before completing stats */ 367 if (d->lock) 368 spin_lock_bh(d->lock); 369 if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 || 370 gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0) 371 return -1; 372 } else { 373 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 374 375 sch = dev_queue->qdisc_sleeping; 376 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), 377 d, NULL, &sch->bstats) < 0 || 378 gnet_stats_copy_queue(d, NULL, 379 &sch->qstats, sch->q.qlen) < 0) 380 return -1; 381 } 382 return 0; 383 } 384 385 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 386 { 387 struct net_device *dev = qdisc_dev(sch); 388 unsigned long ntx; 389 390 if (arg->stop) 391 return; 392 393 /* Walk hierarchy with a virtual class per tc */ 394 arg->count = arg->skip; 395 for (ntx = arg->skip; 396 ntx < dev->num_tx_queues + netdev_get_num_tc(dev); 397 ntx++) { 398 if (arg->fn(sch, ntx + 1, arg) < 0) { 399 arg->stop = 1; 400 break; 401 } 402 arg->count++; 403 } 404 } 405 406 static const struct Qdisc_class_ops mqprio_class_ops = { 407 .graft = mqprio_graft, 408 .leaf = mqprio_leaf, 409 .get = mqprio_get, 410 .put = mqprio_put, 411 .walk = mqprio_walk, 412 .dump = mqprio_dump_class, 413 .dump_stats = mqprio_dump_class_stats, 414 }; 415 416 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = { 417 .cl_ops = &mqprio_class_ops, 418 .id = "mqprio", 419 .priv_size = sizeof(struct mqprio_sched), 420 .init = mqprio_init, 421 .destroy = mqprio_destroy, 422 .attach = mqprio_attach, 423 .dump = mqprio_dump, 424 .owner = THIS_MODULE, 425 }; 426 427 static int __init mqprio_module_init(void) 428 { 429 return register_qdisc(&mqprio_qdisc_ops); 430 } 431 432 static void __exit mqprio_module_exit(void) 433 { 434 unregister_qdisc(&mqprio_qdisc_ops); 435 } 436 437 module_init(mqprio_module_init); 438 module_exit(mqprio_module_exit); 439 440 MODULE_LICENSE("GPL"); 441