root/net/sched/sch_mqprio.c

DEFINITIONS

1. mqprio_destroy
2. mqprio_parse_opt
3. parse_attr
4. mqprio_init
5. mqprio_attach
6. mqprio_queue_get
7. mqprio_graft
8. dump_rates
9. mqprio_dump
10. mqprio_leaf
11. mqprio_find
12. mqprio_dump_class
13. mqprio_dump_class_stats
14. mqprio_walk
15. mqprio_select_queue
16. mqprio_module_init
17. mqprio_module_exit

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * net/sched/sch_mqprio.c
   4  *
   5  * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
   6  */
   7 
   8 #include <linux/types.h>
   9 #include <linux/slab.h>
  10 #include <linux/kernel.h>
  11 #include <linux/string.h>
  12 #include <linux/errno.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/module.h>
  15 #include <net/netlink.h>
  16 #include <net/pkt_sched.h>
  17 #include <net/sch_generic.h>
  18 #include <net/pkt_cls.h>
  19 
  20 struct mqprio_sched {
  21         struct Qdisc            **qdiscs;
  22         u16 mode;
  23         u16 shaper;
  24         int hw_offload;
  25         u32 flags;
  26         u64 min_rate[TC_QOPT_MAX_QUEUE];
  27         u64 max_rate[TC_QOPT_MAX_QUEUE];
  28 };
  29 
  30 static void mqprio_destroy(struct Qdisc *sch)
  31 {
  32         struct net_device *dev = qdisc_dev(sch);
  33         struct mqprio_sched *priv = qdisc_priv(sch);
  34         unsigned int ntx;
  35 
  36         if (priv->qdiscs) {
  37                 for (ntx = 0;
  38                      ntx < dev->num_tx_queues && priv->qdiscs[ntx];
  39                      ntx++)
  40                         qdisc_put(priv->qdiscs[ntx]);
  41                 kfree(priv->qdiscs);
  42         }
  43 
  44         if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc) {
  45                 struct tc_mqprio_qopt_offload mqprio = { { 0 } };
  46 
  47                 switch (priv->mode) {
  48                 case TC_MQPRIO_MODE_DCB:
  49                 case TC_MQPRIO_MODE_CHANNEL:
  50                         dev->netdev_ops->ndo_setup_tc(dev,
  51                                                       TC_SETUP_QDISC_MQPRIO,
  52                                                       &mqprio);
  53                         break;
  54                 default:
  55                         return;
  56                 }
  57         } else {
  58                 netdev_set_num_tc(dev, 0);
  59         }
  60 }
  61 
  62 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
  63 {
  64         int i, j;
  65 
  66         /* Verify num_tc is not out of max range */
  67         if (qopt->num_tc > TC_MAX_QUEUE)
  68                 return -EINVAL;
  69 
  70         /* Verify priority mapping uses valid tcs */
  71         for (i = 0; i < TC_BITMASK + 1; i++) {
  72                 if (qopt->prio_tc_map[i] >= qopt->num_tc)
  73                         return -EINVAL;
  74         }
  75 
  76         /* Limit qopt->hw to maximum supported offload value.  Drivers have
  77          * the option of overriding this later if they don't support the a
  78          * given offload type.
  79          */
  80         if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
  81                 qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
  82 
  83         /* If hardware offload is requested we will leave it to the device
  84          * to either populate the queue counts itself or to validate the
  85          * provided queue counts.  If ndo_setup_tc is not present then
  86          * hardware doesn't support offload and we should return an error.
  87          */
  88         if (qopt->hw)
  89                 return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
  90 
  91         for (i = 0; i < qopt->num_tc; i++) {
  92                 unsigned int last = qopt->offset[i] + qopt->count[i];
  93 
  94                 /* Verify the queue count is in tx range being equal to the
  95                  * real_num_tx_queues indicates the last queue is in use.
  96                  */
  97                 if (qopt->offset[i] >= dev->real_num_tx_queues ||
  98                     !qopt->count[i] ||
  99                     last > dev->real_num_tx_queues)
 100                         return -EINVAL;
 101 
 102                 /* Verify that the offset and counts do not overlap */
 103                 for (j = i + 1; j < qopt->num_tc; j++) {
 104                         if (last > qopt->offset[j])
 105                                 return -EINVAL;
 106                 }
 107         }
 108 
 109         return 0;
 110 }
 111 
 112 static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {
 113         [TCA_MQPRIO_MODE]       = { .len = sizeof(u16) },
 114         [TCA_MQPRIO_SHAPER]     = { .len = sizeof(u16) },
 115         [TCA_MQPRIO_MIN_RATE64] = { .type = NLA_NESTED },
 116         [TCA_MQPRIO_MAX_RATE64] = { .type = NLA_NESTED },
 117 };
 118 
 119 static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
 120                       const struct nla_policy *policy, int len)
 121 {
 122         int nested_len = nla_len(nla) - NLA_ALIGN(len);
 123 
 124         if (nested_len >= nla_attr_size(0))
 125                 return nla_parse_deprecated(tb, maxtype,
 126                                             nla_data(nla) + NLA_ALIGN(len),
 127                                             nested_len, policy, NULL);
 128 
 129         memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
 130         return 0;
 131 }
 132 
 133 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 134                        struct netlink_ext_ack *extack)
 135 {
 136         struct net_device *dev = qdisc_dev(sch);
 137         struct mqprio_sched *priv = qdisc_priv(sch);
 138         struct netdev_queue *dev_queue;
 139         struct Qdisc *qdisc;
 140         int i, err = -EOPNOTSUPP;
 141         struct tc_mqprio_qopt *qopt = NULL;
 142         struct nlattr *tb[TCA_MQPRIO_MAX + 1];
 143         struct nlattr *attr;
 144         int rem;
 145         int len;
 146 
 147         BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
 148         BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
 149 
 150         if (sch->parent != TC_H_ROOT)
 151                 return -EOPNOTSUPP;
 152 
 153         if (!netif_is_multiqueue(dev))
 154                 return -EOPNOTSUPP;
 155 
 156         /* make certain can allocate enough classids to handle queues */
 157         if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
 158                 return -ENOMEM;
 159 
 160         if (!opt || nla_len(opt) < sizeof(*qopt))
 161                 return -EINVAL;
 162 
 163         qopt = nla_data(opt);
 164         if (mqprio_parse_opt(dev, qopt))
 165                 return -EINVAL;
 166 
 167         len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 168         if (len > 0) {
 169                 err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
 170                                  sizeof(*qopt));
 171                 if (err < 0)
 172                         return err;
 173 
 174                 if (!qopt->hw)
 175                         return -EINVAL;
 176 
 177                 if (tb[TCA_MQPRIO_MODE]) {
 178                         priv->flags |= TC_MQPRIO_F_MODE;
 179                         priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
 180                 }
 181 
 182                 if (tb[TCA_MQPRIO_SHAPER]) {
 183                         priv->flags |= TC_MQPRIO_F_SHAPER;
 184                         priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
 185                 }
 186 
 187                 if (tb[TCA_MQPRIO_MIN_RATE64]) {
 188                         if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
 189                                 return -EINVAL;
 190                         i = 0;
 191                         nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
 192                                             rem) {
 193                                 if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64)
 194                                         return -EINVAL;
 195                                 if (i >= qopt->num_tc)
 196                                         break;
 197                                 priv->min_rate[i] = *(u64 *)nla_data(attr);
 198                                 i++;
 199                         }
 200                         priv->flags |= TC_MQPRIO_F_MIN_RATE;
 201                 }
 202 
 203                 if (tb[TCA_MQPRIO_MAX_RATE64]) {
 204                         if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
 205                                 return -EINVAL;
 206                         i = 0;
 207                         nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
 208                                             rem) {
 209                                 if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64)
 210                                         return -EINVAL;
 211                                 if (i >= qopt->num_tc)
 212                                         break;
 213                                 priv->max_rate[i] = *(u64 *)nla_data(attr);
 214                                 i++;
 215                         }
 216                         priv->flags |= TC_MQPRIO_F_MAX_RATE;
 217                 }
 218         }
 219 
 220         /* pre-allocate qdisc, attachment can't fail */
 221         priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
 222                                GFP_KERNEL);
 223         if (!priv->qdiscs)
 224                 return -ENOMEM;
 225 
 226         for (i = 0; i < dev->num_tx_queues; i++) {
 227                 dev_queue = netdev_get_tx_queue(dev, i);
 228                 qdisc = qdisc_create_dflt(dev_queue,
 229                                           get_default_qdisc_ops(dev, i),
 230                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
 231                                                     TC_H_MIN(i + 1)), extack);
 232                 if (!qdisc)
 233                         return -ENOMEM;
 234 
 235                 priv->qdiscs[i] = qdisc;
 236                 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 237         }
 238 
 239         /* If the mqprio options indicate that hardware should own
 240          * the queue mapping then run ndo_setup_tc otherwise use the
 241          * supplied and verified mapping
 242          */
 243         if (qopt->hw) {
 244                 struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
 245 
 246                 switch (priv->mode) {
 247                 case TC_MQPRIO_MODE_DCB:
 248                         if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
 249                                 return -EINVAL;
 250                         break;
 251                 case TC_MQPRIO_MODE_CHANNEL:
 252                         mqprio.flags = priv->flags;
 253                         if (priv->flags & TC_MQPRIO_F_MODE)
 254                                 mqprio.mode = priv->mode;
 255                         if (priv->flags & TC_MQPRIO_F_SHAPER)
 256                                 mqprio.shaper = priv->shaper;
 257                         if (priv->flags & TC_MQPRIO_F_MIN_RATE)
 258                                 for (i = 0; i < mqprio.qopt.num_tc; i++)
 259                                         mqprio.min_rate[i] = priv->min_rate[i];
 260                         if (priv->flags & TC_MQPRIO_F_MAX_RATE)
 261                                 for (i = 0; i < mqprio.qopt.num_tc; i++)
 262                                         mqprio.max_rate[i] = priv->max_rate[i];
 263                         break;
 264                 default:
 265                         return -EINVAL;
 266                 }
 267                 err = dev->netdev_ops->ndo_setup_tc(dev,
 268                                                     TC_SETUP_QDISC_MQPRIO,
 269                                                     &mqprio);
 270                 if (err)
 271                         return err;
 272 
 273                 priv->hw_offload = mqprio.qopt.hw;
 274         } else {
 275                 netdev_set_num_tc(dev, qopt->num_tc);
 276                 for (i = 0; i < qopt->num_tc; i++)
 277                         netdev_set_tc_queue(dev, i,
 278                                             qopt->count[i], qopt->offset[i]);
 279         }
 280 
 281         /* Always use supplied priority mappings */
 282         for (i = 0; i < TC_BITMASK + 1; i++)
 283                 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
 284 
 285         sch->flags |= TCQ_F_MQROOT;
 286         return 0;
 287 }
 288 
 289 static void mqprio_attach(struct Qdisc *sch)
 290 {
 291         struct net_device *dev = qdisc_dev(sch);
 292         struct mqprio_sched *priv = qdisc_priv(sch);
 293         struct Qdisc *qdisc, *old;
 294         unsigned int ntx;
 295 
 296         /* Attach underlying qdisc */
 297         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 298                 qdisc = priv->qdiscs[ntx];
 299                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
 300                 if (old)
 301                         qdisc_put(old);
 302                 if (ntx < dev->real_num_tx_queues)
 303                         qdisc_hash_add(qdisc, false);
 304         }
 305         kfree(priv->qdiscs);
 306         priv->qdiscs = NULL;
 307 }
 308 
 309 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
 310                                              unsigned long cl)
 311 {
 312         struct net_device *dev = qdisc_dev(sch);
 313         unsigned long ntx = cl - 1;
 314 
 315         if (ntx >= dev->num_tx_queues)
 316                 return NULL;
 317         return netdev_get_tx_queue(dev, ntx);
 318 }
 319 
 320 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 321                         struct Qdisc **old, struct netlink_ext_ack *extack)
 322 {
 323         struct net_device *dev = qdisc_dev(sch);
 324         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 325 
 326         if (!dev_queue)
 327                 return -EINVAL;
 328 
 329         if (dev->flags & IFF_UP)
 330                 dev_deactivate(dev);
 331 
 332         *old = dev_graft_qdisc(dev_queue, new);
 333 
 334         if (new)
 335                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 336 
 337         if (dev->flags & IFF_UP)
 338                 dev_activate(dev);
 339 
 340         return 0;
 341 }
 342 
 343 static int dump_rates(struct mqprio_sched *priv,
 344                       struct tc_mqprio_qopt *opt, struct sk_buff *skb)
 345 {
 346         struct nlattr *nest;
 347         int i;
 348 
 349         if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
 350                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MIN_RATE64);
 351                 if (!nest)
 352                         goto nla_put_failure;
 353 
 354                 for (i = 0; i < opt->num_tc; i++) {
 355                         if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
 356                                     sizeof(priv->min_rate[i]),
 357                                     &priv->min_rate[i]))
 358                                 goto nla_put_failure;
 359                 }
 360                 nla_nest_end(skb, nest);
 361         }
 362 
 363         if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
 364                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MAX_RATE64);
 365                 if (!nest)
 366                         goto nla_put_failure;
 367 
 368                 for (i = 0; i < opt->num_tc; i++) {
 369                         if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
 370                                     sizeof(priv->max_rate[i]),
 371                                     &priv->max_rate[i]))
 372                                 goto nla_put_failure;
 373                 }
 374                 nla_nest_end(skb, nest);
 375         }
 376         return 0;
 377 
 378 nla_put_failure:
 379         nla_nest_cancel(skb, nest);
 380         return -1;
 381 }
 382 
 383 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 384 {
 385         struct net_device *dev = qdisc_dev(sch);
 386         struct mqprio_sched *priv = qdisc_priv(sch);
 387         struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
 388         struct tc_mqprio_qopt opt = { 0 };
 389         struct Qdisc *qdisc;
 390         unsigned int ntx, tc;
 391 
 392         sch->q.qlen = 0;
 393         memset(&sch->bstats, 0, sizeof(sch->bstats));
 394         memset(&sch->qstats, 0, sizeof(sch->qstats));
 395 
 396         /* MQ supports lockless qdiscs. However, statistics accounting needs
 397          * to account for all, none, or a mix of locked and unlocked child
 398          * qdiscs. Percpu stats are added to counters in-band and locking
 399          * qdisc totals are added at end.
 400          */
 401         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 402                 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
 403                 spin_lock_bh(qdisc_lock(qdisc));
 404 
 405                 if (qdisc_is_percpu_stats(qdisc)) {
 406                         __u32 qlen = qdisc_qlen_sum(qdisc);
 407 
 408                         __gnet_stats_copy_basic(NULL, &sch->bstats,
 409                                                 qdisc->cpu_bstats,
 410                                                 &qdisc->bstats);
 411                         __gnet_stats_copy_queue(&sch->qstats,
 412                                                 qdisc->cpu_qstats,
 413                                                 &qdisc->qstats, qlen);
 414                         sch->q.qlen             += qlen;
 415                 } else {
 416                         sch->q.qlen             += qdisc->q.qlen;
 417                         sch->bstats.bytes       += qdisc->bstats.bytes;
 418                         sch->bstats.packets     += qdisc->bstats.packets;
 419                         sch->qstats.backlog     += qdisc->qstats.backlog;
 420                         sch->qstats.drops       += qdisc->qstats.drops;
 421                         sch->qstats.requeues    += qdisc->qstats.requeues;
 422                         sch->qstats.overlimits  += qdisc->qstats.overlimits;
 423                 }
 424 
 425                 spin_unlock_bh(qdisc_lock(qdisc));
 426         }
 427 
 428         opt.num_tc = netdev_get_num_tc(dev);
 429         memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
 430         opt.hw = priv->hw_offload;
 431 
 432         for (tc = 0; tc < netdev_get_num_tc(dev); tc++) {
 433                 opt.count[tc] = dev->tc_to_txq[tc].count;
 434                 opt.offset[tc] = dev->tc_to_txq[tc].offset;
 435         }
 436 
 437         if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 438                 goto nla_put_failure;
 439 
 440         if ((priv->flags & TC_MQPRIO_F_MODE) &&
 441             nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
 442                 goto nla_put_failure;
 443 
 444         if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
 445             nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
 446                 goto nla_put_failure;
 447 
 448         if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
 449              priv->flags & TC_MQPRIO_F_MAX_RATE) &&
 450             (dump_rates(priv, &opt, skb) != 0))
 451                 goto nla_put_failure;
 452 
 453         return nla_nest_end(skb, nla);
 454 nla_put_failure:
 455         nlmsg_trim(skb, nla);
 456         return -1;
 457 }
 458 
 459 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
 460 {
 461         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 462 
 463         if (!dev_queue)
 464                 return NULL;
 465 
 466         return dev_queue->qdisc_sleeping;
 467 }
 468 
 469 static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
 470 {
 471         struct net_device *dev = qdisc_dev(sch);
 472         unsigned int ntx = TC_H_MIN(classid);
 473 
 474         /* There are essentially two regions here that have valid classid
 475          * values. The first region will have a classid value of 1 through
 476          * num_tx_queues. All of these are backed by actual Qdiscs.
 477          */
 478         if (ntx < TC_H_MIN_PRIORITY)
 479                 return (ntx <= dev->num_tx_queues) ? ntx : 0;
 480 
 481         /* The second region represents the hardware traffic classes. These
 482          * are represented by classid values of TC_H_MIN_PRIORITY through
 483          * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
 484          */
 485         return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
 486 }
 487 
 488 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
 489                          struct sk_buff *skb, struct tcmsg *tcm)
 490 {
 491         if (cl < TC_H_MIN_PRIORITY) {
 492                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 493                 struct net_device *dev = qdisc_dev(sch);
 494                 int tc = netdev_txq_to_tc(dev, cl - 1);
 495 
 496                 tcm->tcm_parent = (tc < 0) ? 0 :
 497                         TC_H_MAKE(TC_H_MAJ(sch->handle),
 498                                   TC_H_MIN(tc + TC_H_MIN_PRIORITY));
 499                 tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
 500         } else {
 501                 tcm->tcm_parent = TC_H_ROOT;
 502                 tcm->tcm_info = 0;
 503         }
 504         tcm->tcm_handle |= TC_H_MIN(cl);
 505         return 0;
 506 }
 507 
 508 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 509                                    struct gnet_dump *d)
 510         __releases(d->lock)
 511         __acquires(d->lock)
 512 {
 513         if (cl >= TC_H_MIN_PRIORITY) {
 514                 int i;
 515                 __u32 qlen = 0;
 516                 struct gnet_stats_queue qstats = {0};
 517                 struct gnet_stats_basic_packed bstats = {0};
 518                 struct net_device *dev = qdisc_dev(sch);
 519                 struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
 520 
 521                 /* Drop lock here it will be reclaimed before touching
 522                  * statistics this is required because the d->lock we
 523                  * hold here is the look on dev_queue->qdisc_sleeping
 524                  * also acquired below.
 525                  */
 526                 if (d->lock)
 527                         spin_unlock_bh(d->lock);
 528 
 529                 for (i = tc.offset; i < tc.offset + tc.count; i++) {
 530                         struct netdev_queue *q = netdev_get_tx_queue(dev, i);
 531                         struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
 532                         struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
 533                         struct gnet_stats_queue __percpu *cpu_qstats = NULL;
 534 
 535                         spin_lock_bh(qdisc_lock(qdisc));
 536                         if (qdisc_is_percpu_stats(qdisc)) {
 537                                 cpu_bstats = qdisc->cpu_bstats;
 538                                 cpu_qstats = qdisc->cpu_qstats;
 539                         }
 540 
 541                         qlen = qdisc_qlen_sum(qdisc);
 542                         __gnet_stats_copy_basic(NULL, &sch->bstats,
 543                                                 cpu_bstats, &qdisc->bstats);
 544                         __gnet_stats_copy_queue(&sch->qstats,
 545                                                 cpu_qstats,
 546                                                 &qdisc->qstats,
 547                                                 qlen);
 548                         spin_unlock_bh(qdisc_lock(qdisc));
 549                 }
 550 
 551                 /* Reclaim root sleeping lock before completing stats */
 552                 if (d->lock)
 553                         spin_lock_bh(d->lock);
 554                 if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 ||
 555                     gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
 556                         return -1;
 557         } else {
 558                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 559 
 560                 sch = dev_queue->qdisc_sleeping;
 561                 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
 562                                           sch->cpu_bstats, &sch->bstats) < 0 ||
 563                     qdisc_qstats_copy(d, sch) < 0)
 564                         return -1;
 565         }
 566         return 0;
 567 }
 568 
 569 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 570 {
 571         struct net_device *dev = qdisc_dev(sch);
 572         unsigned long ntx;
 573 
 574         if (arg->stop)
 575                 return;
 576 
 577         /* Walk hierarchy with a virtual class per tc */
 578         arg->count = arg->skip;
 579         for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
 580                 if (arg->fn(sch, ntx + TC_H_MIN_PRIORITY, arg) < 0) {
 581                         arg->stop = 1;
 582                         return;
 583                 }
 584                 arg->count++;
 585         }
 586 
 587         /* Pad the values and skip over unused traffic classes */
 588         if (ntx < TC_MAX_QUEUE) {
 589                 arg->count = TC_MAX_QUEUE;
 590                 ntx = TC_MAX_QUEUE;
 591         }
 592 
 593         /* Reset offset, sort out remaining per-queue qdiscs */
 594         for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
 595                 if (arg->fn(sch, ntx + 1, arg) < 0) {
 596                         arg->stop = 1;
 597                         return;
 598                 }
 599                 arg->count++;
 600         }
 601 }
 602 
 603 static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
 604                                                 struct tcmsg *tcm)
 605 {
 606         return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 607 }
 608 
 609 static const struct Qdisc_class_ops mqprio_class_ops = {
 610         .graft          = mqprio_graft,
 611         .leaf           = mqprio_leaf,
 612         .find           = mqprio_find,
 613         .walk           = mqprio_walk,
 614         .dump           = mqprio_dump_class,
 615         .dump_stats     = mqprio_dump_class_stats,
 616         .select_queue   = mqprio_select_queue,
 617 };
 618 
 619 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
 620         .cl_ops         = &mqprio_class_ops,
 621         .id             = "mqprio",
 622         .priv_size      = sizeof(struct mqprio_sched),
 623         .init           = mqprio_init,
 624         .destroy        = mqprio_destroy,
 625         .attach         = mqprio_attach,
 626         .dump           = mqprio_dump,
 627         .owner          = THIS_MODULE,
 628 };
 629 
 630 static int __init mqprio_module_init(void)
 631 {
 632         return register_qdisc(&mqprio_qdisc_ops);
 633 }
 634 
 635 static void __exit mqprio_module_exit(void)
 636 {
 637         unregister_qdisc(&mqprio_qdisc_ops);
 638 }
 639 
 640 module_init(mqprio_module_init);
 641 module_exit(mqprio_module_exit);
 642 
 643 MODULE_LICENSE("GPL");