sched/sch_mqprio.c

   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_parse_nlattr(struct Qdisc *sch, struct tc_mqprio_qopt *qopt,
 134                                struct nlattr *opt,
 135                                struct netlink_ext_ack *extack)
 136 {
 137         struct mqprio_sched *priv = qdisc_priv(sch);
 138         struct nlattr *tb[TCA_MQPRIO_MAX + 1];
 139         struct nlattr *attr;
 140         int i, rem, err;
 141
 142         err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
 143                          sizeof(*qopt));
 144         if (err < 0)
 145                 return err;
 146
 147         if (!qopt->hw) {
 148                 NL_SET_ERR_MSG(extack,
 149                                "mqprio TCA_OPTIONS can only contain netlink attributes in hardware mode");
 150                 return -EINVAL;
 151         }
 152
 153         if (tb[TCA_MQPRIO_MODE]) {
 154                 priv->flags |= TC_MQPRIO_F_MODE;
 155                 priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
 156         }
 157
 158         if (tb[TCA_MQPRIO_SHAPER]) {
 159                 priv->flags |= TC_MQPRIO_F_SHAPER;
 160                 priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
 161         }
 162
 163         if (tb[TCA_MQPRIO_MIN_RATE64]) {
 164                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 165                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MIN_RATE64],
 166                                             "min_rate accepted only when shaper is in bw_rlimit mode");
 167                         return -EINVAL;
 168                 }
 169                 i = 0;
 170                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
 171                                     rem) {
 172                         if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64) {
 173                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 174                                                     "Attribute type expected to be TCA_MQPRIO_MIN_RATE64");
 175                                 return -EINVAL;
 176                         }
 177
 178                         if (nla_len(attr) != sizeof(u64)) {
 179                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 180                                                     "Attribute TCA_MQPRIO_MIN_RATE64 expected to have 8 bytes length");
 181                                 return -EINVAL;
 182                         }
 183
 184                         if (i >= qopt->num_tc)
 185                                 break;
 186                         priv->min_rate[i] = *(u64 *)nla_data(attr);
 187                         i++;
 188                 }
 189                 priv->flags |= TC_MQPRIO_F_MIN_RATE;
 190         }
 191
 192         if (tb[TCA_MQPRIO_MAX_RATE64]) {
 193                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 194                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MAX_RATE64],
 195                                             "max_rate accepted only when shaper is in bw_rlimit mode");
 196                         return -EINVAL;
 197                 }
 198                 i = 0;
 199                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
 200                                     rem) {
 201                         if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64) {
 202                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 203                                                     "Attribute type expected to be TCA_MQPRIO_MAX_RATE64");
 204                                 return -EINVAL;
 205                         }
 206
 207                         if (nla_len(attr) != sizeof(u64)) {
 208                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 209                                                     "Attribute TCA_MQPRIO_MAX_RATE64 expected to have 8 bytes length");
 210                                 return -EINVAL;
 211                         }
 212
 213                         if (i >= qopt->num_tc)
 214                                 break;
 215                         priv->max_rate[i] = *(u64 *)nla_data(attr);
 216                         i++;
 217                 }
 218                 priv->flags |= TC_MQPRIO_F_MAX_RATE;
 219         }
 220
 221         return 0;
 222 }
 223
 224 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 225                        struct netlink_ext_ack *extack)
 226 {
 227         struct net_device *dev = qdisc_dev(sch);
 228         struct mqprio_sched *priv = qdisc_priv(sch);
 229         struct netdev_queue *dev_queue;
 230         struct Qdisc *qdisc;
 231         int i, err = -EOPNOTSUPP;
 232         struct tc_mqprio_qopt *qopt = NULL;
 233         int len;
 234
 235         BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
 236         BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
 237
 238         if (sch->parent != TC_H_ROOT)
 239                 return -EOPNOTSUPP;
 240
 241         if (!netif_is_multiqueue(dev))
 242                 return -EOPNOTSUPP;
 243
 244         /* make certain can allocate enough classids to handle queues */
 245         if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
 246                 return -ENOMEM;
 247
 248         if (!opt || nla_len(opt) < sizeof(*qopt))
 249                 return -EINVAL;
 250
 251         qopt = nla_data(opt);
 252         if (mqprio_parse_opt(dev, qopt))
 253                 return -EINVAL;
 254
 255         len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 256         if (len > 0) {
 257                 err = mqprio_parse_nlattr(sch, qopt, opt, extack);
 258                 if (err)
 259                         return err;
 260         }
 261
 262         /* pre-allocate qdisc, attachment can't fail */
 263         priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
 264                                GFP_KERNEL);
 265         if (!priv->qdiscs)
 266                 return -ENOMEM;
 267
 268         for (i = 0; i < dev->num_tx_queues; i++) {
 269                 dev_queue = netdev_get_tx_queue(dev, i);
 270                 qdisc = qdisc_create_dflt(dev_queue,
 271                                           get_default_qdisc_ops(dev, i),
 272                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
 273                                                     TC_H_MIN(i + 1)), extack);
 274                 if (!qdisc)
 275                         return -ENOMEM;
 276
 277                 priv->qdiscs[i] = qdisc;
 278                 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 279         }
 280
 281         /* If the mqprio options indicate that hardware should own
 282          * the queue mapping then run ndo_setup_tc otherwise use the
 283          * supplied and verified mapping
 284          */
 285         if (qopt->hw) {
 286                 struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
 287
 288                 switch (priv->mode) {
 289                 case TC_MQPRIO_MODE_DCB:
 290                         if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
 291                                 return -EINVAL;
 292                         break;
 293                 case TC_MQPRIO_MODE_CHANNEL:
 294                         mqprio.flags = priv->flags;
 295                         if (priv->flags & TC_MQPRIO_F_MODE)
 296                                 mqprio.mode = priv->mode;
 297                         if (priv->flags & TC_MQPRIO_F_SHAPER)
 298                                 mqprio.shaper = priv->shaper;
 299                         if (priv->flags & TC_MQPRIO_F_MIN_RATE)
 300                                 for (i = 0; i < mqprio.qopt.num_tc; i++)
 301                                         mqprio.min_rate[i] = priv->min_rate[i];
 302                         if (priv->flags & TC_MQPRIO_F_MAX_RATE)
 303                                 for (i = 0; i < mqprio.qopt.num_tc; i++)
 304                                         mqprio.max_rate[i] = priv->max_rate[i];
 305                         break;
 306                 default:
 307                         return -EINVAL;
 308                 }
 309                 err = dev->netdev_ops->ndo_setup_tc(dev,
 310                                                     TC_SETUP_QDISC_MQPRIO,
 311                                                     &mqprio);
 312                 if (err)
 313                         return err;
 314
 315                 priv->hw_offload = mqprio.qopt.hw;
 316         } else {
 317                 netdev_set_num_tc(dev, qopt->num_tc);
 318                 for (i = 0; i < qopt->num_tc; i++)
 319                         netdev_set_tc_queue(dev, i,
 320                                             qopt->count[i], qopt->offset[i]);
 321         }
 322
 323         /* Always use supplied priority mappings */
 324         for (i = 0; i < TC_BITMASK + 1; i++)
 325                 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
 326
 327         sch->flags |= TCQ_F_MQROOT;
 328         return 0;
 329 }
 330
 331 static void mqprio_attach(struct Qdisc *sch)
 332 {
 333         struct net_device *dev = qdisc_dev(sch);
 334         struct mqprio_sched *priv = qdisc_priv(sch);
 335         struct Qdisc *qdisc, *old;
 336         unsigned int ntx;
 337
 338         /* Attach underlying qdisc */
 339         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 340                 qdisc = priv->qdiscs[ntx];
 341                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
 342                 if (old)
 343                         qdisc_put(old);
 344                 if (ntx < dev->real_num_tx_queues)
 345                         qdisc_hash_add(qdisc, false);
 346         }
 347         kfree(priv->qdiscs);
 348         priv->qdiscs = NULL;
 349 }
 350
 351 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
 352                                              unsigned long cl)
 353 {
 354         struct net_device *dev = qdisc_dev(sch);
 355         unsigned long ntx = cl - 1;
 356
 357         if (ntx >= dev->num_tx_queues)
 358                 return NULL;
 359         return netdev_get_tx_queue(dev, ntx);
 360 }
 361
 362 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 363                         struct Qdisc **old, struct netlink_ext_ack *extack)
 364 {
 365         struct net_device *dev = qdisc_dev(sch);
 366         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 367
 368         if (!dev_queue)
 369                 return -EINVAL;
 370
 371         if (dev->flags & IFF_UP)
 372                 dev_deactivate(dev);
 373
 374         *old = dev_graft_qdisc(dev_queue, new);
 375
 376         if (new)
 377                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 378
 379         if (dev->flags & IFF_UP)
 380                 dev_activate(dev);
 381
 382         return 0;
 383 }
 384
 385 static int dump_rates(struct mqprio_sched *priv,
 386                       struct tc_mqprio_qopt *opt, struct sk_buff *skb)
 387 {
 388         struct nlattr *nest;
 389         int i;
 390
 391         if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
 392                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MIN_RATE64);
 393                 if (!nest)
 394                         goto nla_put_failure;
 395
 396                 for (i = 0; i < opt->num_tc; i++) {
 397                         if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
 398                                     sizeof(priv->min_rate[i]),
 399                                     &priv->min_rate[i]))
 400                                 goto nla_put_failure;
 401                 }
 402                 nla_nest_end(skb, nest);
 403         }
 404
 405         if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
 406                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MAX_RATE64);
 407                 if (!nest)
 408                         goto nla_put_failure;
 409
 410                 for (i = 0; i < opt->num_tc; i++) {
 411                         if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
 412                                     sizeof(priv->max_rate[i]),
 413                                     &priv->max_rate[i]))
 414                                 goto nla_put_failure;
 415                 }
 416                 nla_nest_end(skb, nest);
 417         }
 418         return 0;
 419
 420 nla_put_failure:
 421         nla_nest_cancel(skb, nest);
 422         return -1;
 423 }
 424
 425 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 426 {
 427         struct net_device *dev = qdisc_dev(sch);
 428         struct mqprio_sched *priv = qdisc_priv(sch);
 429         struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
 430         struct tc_mqprio_qopt opt = { 0 };
 431         struct Qdisc *qdisc;
 432         unsigned int ntx, tc;
 433
 434         sch->q.qlen = 0;
 435         gnet_stats_basic_sync_init(&sch->bstats);
 436         memset(&sch->qstats, 0, sizeof(sch->qstats));
 437
 438         /* MQ supports lockless qdiscs. However, statistics accounting needs
 439          * to account for all, none, or a mix of locked and unlocked child
 440          * qdiscs. Percpu stats are added to counters in-band and locking
 441          * qdisc totals are added at end.
 442          */
 443         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 444                 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping);
 445                 spin_lock_bh(qdisc_lock(qdisc));
 446
 447                 gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats,
 448                                      &qdisc->bstats, false);
 449                 gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
 450                                      &qdisc->qstats);
 451                 sch->q.qlen += qdisc_qlen(qdisc);
 452
 453                 spin_unlock_bh(qdisc_lock(qdisc));
 454         }
 455
 456         opt.num_tc = netdev_get_num_tc(dev);
 457         memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
 458         opt.hw = priv->hw_offload;
 459
 460         for (tc = 0; tc < netdev_get_num_tc(dev); tc++) {
 461                 opt.count[tc] = dev->tc_to_txq[tc].count;
 462                 opt.offset[tc] = dev->tc_to_txq[tc].offset;
 463         }
 464
 465         if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 466                 goto nla_put_failure;
 467
 468         if ((priv->flags & TC_MQPRIO_F_MODE) &&
 469             nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
 470                 goto nla_put_failure;
 471
 472         if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
 473             nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
 474                 goto nla_put_failure;
 475
 476         if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
 477              priv->flags & TC_MQPRIO_F_MAX_RATE) &&
 478             (dump_rates(priv, &opt, skb) != 0))
 479                 goto nla_put_failure;
 480
 481         return nla_nest_end(skb, nla);
 482 nla_put_failure:
 483         nlmsg_trim(skb, nla);
 484         return -1;
 485 }
 486
 487 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
 488 {
 489         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 490
 491         if (!dev_queue)
 492                 return NULL;
 493
 494         return rtnl_dereference(dev_queue->qdisc_sleeping);
 495 }
 496
 497 static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
 498 {
 499         struct net_device *dev = qdisc_dev(sch);
 500         unsigned int ntx = TC_H_MIN(classid);
 501
 502         /* There are essentially two regions here that have valid classid
 503          * values. The first region will have a classid value of 1 through
 504          * num_tx_queues. All of these are backed by actual Qdiscs.
 505          */
 506         if (ntx < TC_H_MIN_PRIORITY)
 507                 return (ntx <= dev->num_tx_queues) ? ntx : 0;
 508
 509         /* The second region represents the hardware traffic classes. These
 510          * are represented by classid values of TC_H_MIN_PRIORITY through
 511          * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
 512          */
 513         return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
 514 }
 515
 516 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
 517                          struct sk_buff *skb, struct tcmsg *tcm)
 518 {
 519         if (cl < TC_H_MIN_PRIORITY) {
 520                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 521                 struct net_device *dev = qdisc_dev(sch);
 522                 int tc = netdev_txq_to_tc(dev, cl - 1);
 523
 524                 tcm->tcm_parent = (tc < 0) ? 0 :
 525                         TC_H_MAKE(TC_H_MAJ(sch->handle),
 526                                   TC_H_MIN(tc + TC_H_MIN_PRIORITY));
 527                 tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle;
 528         } else {
 529                 tcm->tcm_parent = TC_H_ROOT;
 530                 tcm->tcm_info = 0;
 531         }
 532         tcm->tcm_handle |= TC_H_MIN(cl);
 533         return 0;
 534 }
 535
 536 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 537                                    struct gnet_dump *d)
 538         __releases(d->lock)
 539         __acquires(d->lock)
 540 {
 541         if (cl >= TC_H_MIN_PRIORITY) {
 542                 int i;
 543                 __u32 qlen;
 544                 struct gnet_stats_queue qstats = {0};
 545                 struct gnet_stats_basic_sync bstats;
 546                 struct net_device *dev = qdisc_dev(sch);
 547                 struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
 548
 549                 gnet_stats_basic_sync_init(&bstats);
 550                 /* Drop lock here it will be reclaimed before touching
 551                  * statistics this is required because the d->lock we
 552                  * hold here is the look on dev_queue->qdisc_sleeping
 553                  * also acquired below.
 554                  */
 555                 if (d->lock)
 556                         spin_unlock_bh(d->lock);
 557
 558                 for (i = tc.offset; i < tc.offset + tc.count; i++) {
 559                         struct netdev_queue *q = netdev_get_tx_queue(dev, i);
 560                         struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
 561
 562                         spin_lock_bh(qdisc_lock(qdisc));
 563
 564                         gnet_stats_add_basic(&bstats, qdisc->cpu_bstats,
 565                                              &qdisc->bstats, false);
 566                         gnet_stats_add_queue(&qstats, qdisc->cpu_qstats,
 567                                              &qdisc->qstats);
 568                         sch->q.qlen += qdisc_qlen(qdisc);
 569
 570                         spin_unlock_bh(qdisc_lock(qdisc));
 571                 }
 572                 qlen = qdisc_qlen(sch) + qstats.qlen;
 573
 574                 /* Reclaim root sleeping lock before completing stats */
 575                 if (d->lock)
 576                         spin_lock_bh(d->lock);
 577                 if (gnet_stats_copy_basic(d, NULL, &bstats, false) < 0 ||
 578                     gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
 579                         return -1;
 580         } else {
 581                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 582
 583                 sch = rtnl_dereference(dev_queue->qdisc_sleeping);
 584                 if (gnet_stats_copy_basic(d, sch->cpu_bstats,
 585                                           &sch->bstats, true) < 0 ||
 586                     qdisc_qstats_copy(d, sch) < 0)
 587                         return -1;
 588         }
 589         return 0;
 590 }
 591
 592 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 593 {
 594         struct net_device *dev = qdisc_dev(sch);
 595         unsigned long ntx;
 596
 597         if (arg->stop)
 598                 return;
 599
 600         /* Walk hierarchy with a virtual class per tc */
 601         arg->count = arg->skip;
 602         for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
 603                 if (!tc_qdisc_stats_dump(sch, ntx + TC_H_MIN_PRIORITY, arg))
 604                         return;
 605         }
 606
 607         /* Pad the values and skip over unused traffic classes */
 608         if (ntx < TC_MAX_QUEUE) {
 609                 arg->count = TC_MAX_QUEUE;
 610                 ntx = TC_MAX_QUEUE;
 611         }
 612
 613         /* Reset offset, sort out remaining per-queue qdiscs */
 614         for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
 615                 if (arg->fn(sch, ntx + 1, arg) < 0) {
 616                         arg->stop = 1;
 617                         return;
 618                 }
 619                 arg->count++;
 620         }
 621 }
 622
 623 static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
 624                                                 struct tcmsg *tcm)
 625 {
 626         return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 627 }
 628
 629 static const struct Qdisc_class_ops mqprio_class_ops = {
 630         .graft          = mqprio_graft,
 631         .leaf           = mqprio_leaf,
 632         .find           = mqprio_find,
 633         .walk           = mqprio_walk,
 634         .dump           = mqprio_dump_class,
 635         .dump_stats     = mqprio_dump_class_stats,
 636         .select_queue   = mqprio_select_queue,
 637 };
 638
 639 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
 640         .cl_ops         = &mqprio_class_ops,
 641         .id             = "mqprio",
 642         .priv_size      = sizeof(struct mqprio_sched),
 643         .init           = mqprio_init,
 644         .destroy        = mqprio_destroy,
 645         .attach         = mqprio_attach,
 646         .change_real_num_tx = mq_change_real_num_tx,
 647         .dump           = mqprio_dump,
 648         .owner          = THIS_MODULE,
 649 };
 650
 651 static int __init mqprio_module_init(void)
 652 {
 653         return register_qdisc(&mqprio_qdisc_ops);
 654 }
 655
 656 static void __exit mqprio_module_exit(void)
 657 {
 658         unregister_qdisc(&mqprio_qdisc_ops);
 659 }
 660
 661 module_init(mqprio_module_init);
 662 module_exit(mqprio_module_exit);
 663
 664 MODULE_LICENSE("GPL");