net/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/ethtool_netlink.h>
   9 #include <linux/types.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/errno.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/module.h>
  16 #include <net/netlink.h>
  17 #include <net/pkt_sched.h>
  18 #include <net/sch_generic.h>
  19 #include <net/pkt_cls.h>
  20
  21 #include "sch_mqprio_lib.h"
  22
  23 struct mqprio_sched {
  24         struct Qdisc            **qdiscs;
  25         u16 mode;
  26         u16 shaper;
  27         int hw_offload;
  28         u32 flags;
  29         u64 min_rate[TC_QOPT_MAX_QUEUE];
  30         u64 max_rate[TC_QOPT_MAX_QUEUE];
  31         u32 fp[TC_QOPT_MAX_QUEUE];
  32 };
  33
  34 static int mqprio_enable_offload(struct Qdisc *sch,
  35                                  const struct tc_mqprio_qopt *qopt,
  36                                  struct netlink_ext_ack *extack)
  37 {
  38         struct mqprio_sched *priv = qdisc_priv(sch);
  39         struct net_device *dev = qdisc_dev(sch);
  40         struct tc_mqprio_qopt_offload mqprio = {
  41                 .qopt = *qopt,
  42                 .extack = extack,
  43         };
  44         int err, i;
  45
  46         switch (priv->mode) {
  47         case TC_MQPRIO_MODE_DCB:
  48                 if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
  49                         return -EINVAL;
  50                 break;
  51         case TC_MQPRIO_MODE_CHANNEL:
  52                 mqprio.flags = priv->flags;
  53                 if (priv->flags & TC_MQPRIO_F_MODE)
  54                         mqprio.mode = priv->mode;
  55                 if (priv->flags & TC_MQPRIO_F_SHAPER)
  56                         mqprio.shaper = priv->shaper;
  57                 if (priv->flags & TC_MQPRIO_F_MIN_RATE)
  58                         for (i = 0; i < mqprio.qopt.num_tc; i++)
  59                                 mqprio.min_rate[i] = priv->min_rate[i];
  60                 if (priv->flags & TC_MQPRIO_F_MAX_RATE)
  61                         for (i = 0; i < mqprio.qopt.num_tc; i++)
  62                                 mqprio.max_rate[i] = priv->max_rate[i];
  63                 break;
  64         default:
  65                 return -EINVAL;
  66         }
  67
  68         mqprio_fp_to_offload(priv->fp, &mqprio);
  69
  70         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_MQPRIO,
  71                                             &mqprio);
  72         if (err)
  73                 return err;
  74
  75         priv->hw_offload = mqprio.qopt.hw;
  76
  77         return 0;
  78 }
  79
  80 static void mqprio_disable_offload(struct Qdisc *sch)
  81 {
  82         struct tc_mqprio_qopt_offload mqprio = { { 0 } };
  83         struct mqprio_sched *priv = qdisc_priv(sch);
  84         struct net_device *dev = qdisc_dev(sch);
  85
  86         switch (priv->mode) {
  87         case TC_MQPRIO_MODE_DCB:
  88         case TC_MQPRIO_MODE_CHANNEL:
  89                 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_MQPRIO,
  90                                               &mqprio);
  91                 break;
  92         }
  93 }
  94
  95 static void mqprio_destroy(struct Qdisc *sch)
  96 {
  97         struct net_device *dev = qdisc_dev(sch);
  98         struct mqprio_sched *priv = qdisc_priv(sch);
  99         unsigned int ntx;
 100
 101         if (priv->qdiscs) {
 102                 for (ntx = 0;
 103                      ntx < dev->num_tx_queues && priv->qdiscs[ntx];
 104                      ntx++)
 105                         qdisc_put(priv->qdiscs[ntx]);
 106                 kfree(priv->qdiscs);
 107         }
 108
 109         if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc)
 110                 mqprio_disable_offload(sch);
 111         else
 112                 netdev_set_num_tc(dev, 0);
 113 }
 114
 115 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt,
 116                             const struct tc_mqprio_caps *caps,
 117                             struct netlink_ext_ack *extack)
 118 {
 119         int err;
 120
 121         /* Limit qopt->hw to maximum supported offload value.  Drivers have
 122          * the option of overriding this later if they don't support the a
 123          * given offload type.
 124          */
 125         if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
 126                 qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
 127
 128         /* If hardware offload is requested, we will leave 3 options to the
 129          * device driver:
 130          * - populate the queue counts itself (and ignore what was requested)
 131          * - validate the provided queue counts by itself (and apply them)
 132          * - request queue count validation here (and apply them)
 133          */
 134         err = mqprio_validate_qopt(dev, qopt,
 135                                    !qopt->hw || caps->validate_queue_counts,
 136                                    false, extack);
 137         if (err)
 138                 return err;
 139
 140         /* If ndo_setup_tc is not present then hardware doesn't support offload
 141          * and we should return an error.
 142          */
 143         if (qopt->hw && !dev->netdev_ops->ndo_setup_tc) {
 144                 NL_SET_ERR_MSG(extack,
 145                                "Device does not support hardware offload");
 146                 return -EINVAL;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static const struct
 153 nla_policy mqprio_tc_entry_policy[TCA_MQPRIO_TC_ENTRY_MAX + 1] = {
 154         [TCA_MQPRIO_TC_ENTRY_INDEX]     = NLA_POLICY_MAX(NLA_U32,
 155                                                          TC_QOPT_MAX_QUEUE),
 156         [TCA_MQPRIO_TC_ENTRY_FP]        = NLA_POLICY_RANGE(NLA_U32,
 157                                                            TC_FP_EXPRESS,
 158                                                            TC_FP_PREEMPTIBLE),
 159 };
 160
 161 static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {
 162         [TCA_MQPRIO_MODE]       = { .len = sizeof(u16) },
 163         [TCA_MQPRIO_SHAPER]     = { .len = sizeof(u16) },
 164         [TCA_MQPRIO_MIN_RATE64] = { .type = NLA_NESTED },
 165         [TCA_MQPRIO_MAX_RATE64] = { .type = NLA_NESTED },
 166         [TCA_MQPRIO_TC_ENTRY]   = { .type = NLA_NESTED },
 167 };
 168
 169 static int mqprio_parse_tc_entry(u32 fp[TC_QOPT_MAX_QUEUE],
 170                                  struct nlattr *opt,
 171                                  unsigned long *seen_tcs,
 172                                  struct netlink_ext_ack *extack)
 173 {
 174         struct nlattr *tb[TCA_MQPRIO_TC_ENTRY_MAX + 1];
 175         int err, tc;
 176
 177         err = nla_parse_nested(tb, TCA_MQPRIO_TC_ENTRY_MAX, opt,
 178                                mqprio_tc_entry_policy, extack);
 179         if (err < 0)
 180                 return err;
 181
 182         if (NL_REQ_ATTR_CHECK(extack, opt, tb, TCA_MQPRIO_TC_ENTRY_INDEX)) {
 183                 NL_SET_ERR_MSG(extack, "TC entry index missing");
 184                 return -EINVAL;
 185         }
 186
 187         tc = nla_get_u32(tb[TCA_MQPRIO_TC_ENTRY_INDEX]);
 188         if (*seen_tcs & BIT(tc)) {
 189                 NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_TC_ENTRY_INDEX],
 190                                     "Duplicate tc entry");
 191                 return -EINVAL;
 192         }
 193
 194         *seen_tcs |= BIT(tc);
 195
 196         if (tb[TCA_MQPRIO_TC_ENTRY_FP])
 197                 fp[tc] = nla_get_u32(tb[TCA_MQPRIO_TC_ENTRY_FP]);
 198
 199         return 0;
 200 }
 201
 202 static int mqprio_parse_tc_entries(struct Qdisc *sch, struct nlattr *nlattr_opt,
 203                                    int nlattr_opt_len,
 204                                    struct netlink_ext_ack *extack)
 205 {
 206         struct mqprio_sched *priv = qdisc_priv(sch);
 207         struct net_device *dev = qdisc_dev(sch);
 208         bool have_preemption = false;
 209         unsigned long seen_tcs = 0;
 210         u32 fp[TC_QOPT_MAX_QUEUE];
 211         struct nlattr *n;
 212         int tc, rem;
 213         int err = 0;
 214
 215         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
 216                 fp[tc] = priv->fp[tc];
 217
 218         nla_for_each_attr(n, nlattr_opt, nlattr_opt_len, rem) {
 219                 if (nla_type(n) != TCA_MQPRIO_TC_ENTRY)
 220                         continue;
 221
 222                 err = mqprio_parse_tc_entry(fp, n, &seen_tcs, extack);
 223                 if (err)
 224                         goto out;
 225         }
 226
 227         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
 228                 priv->fp[tc] = fp[tc];
 229                 if (fp[tc] == TC_FP_PREEMPTIBLE)
 230                         have_preemption = true;
 231         }
 232
 233         if (have_preemption && !ethtool_dev_mm_supported(dev)) {
 234                 NL_SET_ERR_MSG(extack, "Device does not support preemption");
 235                 return -EOPNOTSUPP;
 236         }
 237 out:
 238         return err;
 239 }
 240
 241 /* Parse the other netlink attributes that represent the payload of
 242  * TCA_OPTIONS, which are appended right after struct tc_mqprio_qopt.
 243  */
 244 static int mqprio_parse_nlattr(struct Qdisc *sch, struct tc_mqprio_qopt *qopt,
 245                                struct nlattr *opt,
 246                                struct netlink_ext_ack *extack)
 247 {
 248         struct nlattr *nlattr_opt = nla_data(opt) + NLA_ALIGN(sizeof(*qopt));
 249         int nlattr_opt_len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 250         struct mqprio_sched *priv = qdisc_priv(sch);
 251         struct nlattr *tb[TCA_MQPRIO_MAX + 1] = {};
 252         struct nlattr *attr;
 253         int i, rem, err;
 254
 255         if (nlattr_opt_len >= nla_attr_size(0)) {
 256                 err = nla_parse_deprecated(tb, TCA_MQPRIO_MAX, nlattr_opt,
 257                                            nlattr_opt_len, mqprio_policy,
 258                                            NULL);
 259                 if (err < 0)
 260                         return err;
 261         }
 262
 263         if (!qopt->hw) {
 264                 NL_SET_ERR_MSG(extack,
 265                                "mqprio TCA_OPTIONS can only contain netlink attributes in hardware mode");
 266                 return -EINVAL;
 267         }
 268
 269         if (tb[TCA_MQPRIO_MODE]) {
 270                 priv->flags |= TC_MQPRIO_F_MODE;
 271                 priv->mode = nla_get_u16(tb[TCA_MQPRIO_MODE]);
 272         }
 273
 274         if (tb[TCA_MQPRIO_SHAPER]) {
 275                 priv->flags |= TC_MQPRIO_F_SHAPER;
 276                 priv->shaper = nla_get_u16(tb[TCA_MQPRIO_SHAPER]);
 277         }
 278
 279         if (tb[TCA_MQPRIO_MIN_RATE64]) {
 280                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 281                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MIN_RATE64],
 282                                             "min_rate accepted only when shaper is in bw_rlimit mode");
 283                         return -EINVAL;
 284                 }
 285                 i = 0;
 286                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
 287                                     rem) {
 288                         if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64) {
 289                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 290                                                     "Attribute type expected to be TCA_MQPRIO_MIN_RATE64");
 291                                 return -EINVAL;
 292                         }
 293                         if (i >= qopt->num_tc)
 294                                 break;
 295                         priv->min_rate[i] = nla_get_u64(attr);
 296                         i++;
 297                 }
 298                 priv->flags |= TC_MQPRIO_F_MIN_RATE;
 299         }
 300
 301         if (tb[TCA_MQPRIO_MAX_RATE64]) {
 302                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 303                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MAX_RATE64],
 304                                             "max_rate accepted only when shaper is in bw_rlimit mode");
 305                         return -EINVAL;
 306                 }
 307                 i = 0;
 308                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
 309                                     rem) {
 310                         if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64) {
 311                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 312                                                     "Attribute type expected to be TCA_MQPRIO_MAX_RATE64");
 313                                 return -EINVAL;
 314                         }
 315                         if (i >= qopt->num_tc)
 316                                 break;
 317                         priv->max_rate[i] = nla_get_u64(attr);
 318                         i++;
 319                 }
 320                 priv->flags |= TC_MQPRIO_F_MAX_RATE;
 321         }
 322
 323         if (tb[TCA_MQPRIO_TC_ENTRY]) {
 324                 err = mqprio_parse_tc_entries(sch, nlattr_opt, nlattr_opt_len,
 325                                               extack);
 326                 if (err)
 327                         return err;
 328         }
 329
 330         return 0;
 331 }
 332
 333 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 334                        struct netlink_ext_ack *extack)
 335 {
 336         struct net_device *dev = qdisc_dev(sch);
 337         struct mqprio_sched *priv = qdisc_priv(sch);
 338         struct netdev_queue *dev_queue;
 339         struct Qdisc *qdisc;
 340         int i, err = -EOPNOTSUPP;
 341         struct tc_mqprio_qopt *qopt = NULL;
 342         struct tc_mqprio_caps caps;
 343         int len, tc;
 344
 345         BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
 346         BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
 347
 348         if (sch->parent != TC_H_ROOT)
 349                 return -EOPNOTSUPP;
 350
 351         if (!netif_is_multiqueue(dev))
 352                 return -EOPNOTSUPP;
 353
 354         /* make certain can allocate enough classids to handle queues */
 355         if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
 356                 return -ENOMEM;
 357
 358         if (!opt || nla_len(opt) < sizeof(*qopt))
 359                 return -EINVAL;
 360
 361         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
 362                 priv->fp[tc] = TC_FP_EXPRESS;
 363
 364         qdisc_offload_query_caps(dev, TC_SETUP_QDISC_MQPRIO,
 365                                  &caps, sizeof(caps));
 366
 367         qopt = nla_data(opt);
 368         if (mqprio_parse_opt(dev, qopt, &caps, extack))
 369                 return -EINVAL;
 370
 371         len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 372         if (len > 0) {
 373                 err = mqprio_parse_nlattr(sch, qopt, opt, extack);
 374                 if (err)
 375                         return err;
 376         }
 377
 378         /* pre-allocate qdisc, attachment can't fail */
 379         priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
 380                                GFP_KERNEL);
 381         if (!priv->qdiscs)
 382                 return -ENOMEM;
 383
 384         for (i = 0; i < dev->num_tx_queues; i++) {
 385                 dev_queue = netdev_get_tx_queue(dev, i);
 386                 qdisc = qdisc_create_dflt(dev_queue,
 387                                           get_default_qdisc_ops(dev, i),
 388                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
 389                                                     TC_H_MIN(i + 1)), extack);
 390                 if (!qdisc)
 391                         return -ENOMEM;
 392
 393                 priv->qdiscs[i] = qdisc;
 394                 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 395         }
 396
 397         /* If the mqprio options indicate that hardware should own
 398          * the queue mapping then run ndo_setup_tc otherwise use the
 399          * supplied and verified mapping
 400          */
 401         if (qopt->hw) {
 402                 err = mqprio_enable_offload(sch, qopt, extack);
 403                 if (err)
 404                         return err;
 405         } else {
 406                 netdev_set_num_tc(dev, qopt->num_tc);
 407                 for (i = 0; i < qopt->num_tc; i++)
 408                         netdev_set_tc_queue(dev, i,
 409                                             qopt->count[i], qopt->offset[i]);
 410         }
 411
 412         /* Always use supplied priority mappings */
 413         for (i = 0; i < TC_BITMASK + 1; i++)
 414                 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
 415
 416         sch->flags |= TCQ_F_MQROOT;
 417         return 0;
 418 }
 419
 420 static void mqprio_attach(struct Qdisc *sch)
 421 {
 422         struct net_device *dev = qdisc_dev(sch);
 423         struct mqprio_sched *priv = qdisc_priv(sch);
 424         struct Qdisc *qdisc, *old;
 425         unsigned int ntx;
 426
 427         /* Attach underlying qdisc */
 428         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 429                 qdisc = priv->qdiscs[ntx];
 430                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
 431                 if (old)
 432                         qdisc_put(old);
 433                 if (ntx < dev->real_num_tx_queues)
 434                         qdisc_hash_add(qdisc, false);
 435         }
 436         kfree(priv->qdiscs);
 437         priv->qdiscs = NULL;
 438 }
 439
 440 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
 441                                              unsigned long cl)
 442 {
 443         struct net_device *dev = qdisc_dev(sch);
 444         unsigned long ntx = cl - 1;
 445
 446         if (ntx >= dev->num_tx_queues)
 447                 return NULL;
 448         return netdev_get_tx_queue(dev, ntx);
 449 }
 450
 451 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 452                         struct Qdisc **old, struct netlink_ext_ack *extack)
 453 {
 454         struct net_device *dev = qdisc_dev(sch);
 455         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 456
 457         if (!dev_queue)
 458                 return -EINVAL;
 459
 460         if (dev->flags & IFF_UP)
 461                 dev_deactivate(dev);
 462
 463         *old = dev_graft_qdisc(dev_queue, new);
 464
 465         if (new)
 466                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 467
 468         if (dev->flags & IFF_UP)
 469                 dev_activate(dev);
 470
 471         return 0;
 472 }
 473
 474 static int dump_rates(struct mqprio_sched *priv,
 475                       struct tc_mqprio_qopt *opt, struct sk_buff *skb)
 476 {
 477         struct nlattr *nest;
 478         int i;
 479
 480         if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
 481                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MIN_RATE64);
 482                 if (!nest)
 483                         goto nla_put_failure;
 484
 485                 for (i = 0; i < opt->num_tc; i++) {
 486                         if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
 487                                     sizeof(priv->min_rate[i]),
 488                                     &priv->min_rate[i]))
 489                                 goto nla_put_failure;
 490                 }
 491                 nla_nest_end(skb, nest);
 492         }
 493
 494         if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
 495                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MAX_RATE64);
 496                 if (!nest)
 497                         goto nla_put_failure;
 498
 499                 for (i = 0; i < opt->num_tc; i++) {
 500                         if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
 501                                     sizeof(priv->max_rate[i]),
 502                                     &priv->max_rate[i]))
 503                                 goto nla_put_failure;
 504                 }
 505                 nla_nest_end(skb, nest);
 506         }
 507         return 0;
 508
 509 nla_put_failure:
 510         nla_nest_cancel(skb, nest);
 511         return -1;
 512 }
 513
 514 static int mqprio_dump_tc_entries(struct mqprio_sched *priv,
 515                                   struct sk_buff *skb)
 516 {
 517         struct nlattr *n;
 518         int tc;
 519
 520         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
 521                 n = nla_nest_start(skb, TCA_MQPRIO_TC_ENTRY);
 522                 if (!n)
 523                         return -EMSGSIZE;
 524
 525                 if (nla_put_u32(skb, TCA_MQPRIO_TC_ENTRY_INDEX, tc))
 526                         goto nla_put_failure;
 527
 528                 if (nla_put_u32(skb, TCA_MQPRIO_TC_ENTRY_FP, priv->fp[tc]))
 529                         goto nla_put_failure;
 530
 531                 nla_nest_end(skb, n);
 532         }
 533
 534         return 0;
 535
 536 nla_put_failure:
 537         nla_nest_cancel(skb, n);
 538         return -EMSGSIZE;
 539 }
 540
 541 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 542 {
 543         struct net_device *dev = qdisc_dev(sch);
 544         struct mqprio_sched *priv = qdisc_priv(sch);
 545         struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
 546         struct tc_mqprio_qopt opt = { 0 };
 547         struct Qdisc *qdisc;
 548         unsigned int ntx;
 549
 550         sch->q.qlen = 0;
 551         gnet_stats_basic_sync_init(&sch->bstats);
 552         memset(&sch->qstats, 0, sizeof(sch->qstats));
 553
 554         /* MQ supports lockless qdiscs. However, statistics accounting needs
 555          * to account for all, none, or a mix of locked and unlocked child
 556          * qdiscs. Percpu stats are added to counters in-band and locking
 557          * qdisc totals are added at end.
 558          */
 559         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 560                 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
 561                 spin_lock_bh(qdisc_lock(qdisc));
 562
 563                 gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats,
 564                                      &qdisc->bstats, false);
 565                 gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
 566                                      &qdisc->qstats);
 567                 sch->q.qlen += qdisc_qlen(qdisc);
 568
 569                 spin_unlock_bh(qdisc_lock(qdisc));
 570         }
 571
 572         mqprio_qopt_reconstruct(dev, &opt);
 573         opt.hw = priv->hw_offload;
 574
 575         if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 576                 goto nla_put_failure;
 577
 578         if ((priv->flags & TC_MQPRIO_F_MODE) &&
 579             nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
 580                 goto nla_put_failure;
 581
 582         if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
 583             nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
 584                 goto nla_put_failure;
 585
 586         if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
 587              priv->flags & TC_MQPRIO_F_MAX_RATE) &&
 588             (dump_rates(priv, &opt, skb) != 0))
 589                 goto nla_put_failure;
 590
 591         if (mqprio_dump_tc_entries(priv, skb))
 592                 goto nla_put_failure;
 593
 594         return nla_nest_end(skb, nla);
 595 nla_put_failure:
 596         nlmsg_trim(skb, nla);
 597         return -1;
 598 }
 599
 600 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
 601 {
 602         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 603
 604         if (!dev_queue)
 605                 return NULL;
 606
 607         return dev_queue->qdisc_sleeping;
 608 }
 609
 610 static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
 611 {
 612         struct net_device *dev = qdisc_dev(sch);
 613         unsigned int ntx = TC_H_MIN(classid);
 614
 615         /* There are essentially two regions here that have valid classid
 616          * values. The first region will have a classid value of 1 through
 617          * num_tx_queues. All of these are backed by actual Qdiscs.
 618          */
 619         if (ntx < TC_H_MIN_PRIORITY)
 620                 return (ntx <= dev->num_tx_queues) ? ntx : 0;
 621
 622         /* The second region represents the hardware traffic classes. These
 623          * are represented by classid values of TC_H_MIN_PRIORITY through
 624          * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
 625          */
 626         return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
 627 }
 628
 629 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
 630                          struct sk_buff *skb, struct tcmsg *tcm)
 631 {
 632         if (cl < TC_H_MIN_PRIORITY) {
 633                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 634                 struct net_device *dev = qdisc_dev(sch);
 635                 int tc = netdev_txq_to_tc(dev, cl - 1);
 636
 637                 tcm->tcm_parent = (tc < 0) ? 0 :
 638                         TC_H_MAKE(TC_H_MAJ(sch->handle),
 639                                   TC_H_MIN(tc + TC_H_MIN_PRIORITY));
 640                 tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
 641         } else {
 642                 tcm->tcm_parent = TC_H_ROOT;
 643                 tcm->tcm_info = 0;
 644         }
 645         tcm->tcm_handle |= TC_H_MIN(cl);
 646         return 0;
 647 }
 648
 649 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 650                                    struct gnet_dump *d)
 651         __releases(d->lock)
 652         __acquires(d->lock)
 653 {
 654         if (cl >= TC_H_MIN_PRIORITY) {
 655                 int i;
 656                 __u32 qlen;
 657                 struct gnet_stats_queue qstats = {0};
 658                 struct gnet_stats_basic_sync bstats;
 659                 struct net_device *dev = qdisc_dev(sch);
 660                 struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
 661
 662                 gnet_stats_basic_sync_init(&bstats);
 663                 /* Drop lock here it will be reclaimed before touching
 664                  * statistics this is required because the d->lock we
 665                  * hold here is the look on dev_queue->qdisc_sleeping
 666                  * also acquired below.
 667                  */
 668                 if (d->lock)
 669                         spin_unlock_bh(d->lock);
 670
 671                 for (i = tc.offset; i < tc.offset + tc.count; i++) {
 672                         struct netdev_queue *q = netdev_get_tx_queue(dev, i);
 673                         struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
 674
 675                         spin_lock_bh(qdisc_lock(qdisc));
 676
 677                         gnet_stats_add_basic(&bstats, qdisc->cpu_bstats,
 678                                              &qdisc->bstats, false);
 679                         gnet_stats_add_queue(&qstats, qdisc->cpu_qstats,
 680                                              &qdisc->qstats);
 681                         sch->q.qlen += qdisc_qlen(qdisc);
 682
 683                         spin_unlock_bh(qdisc_lock(qdisc));
 684                 }
 685                 qlen = qdisc_qlen(sch) + qstats.qlen;
 686
 687                 /* Reclaim root sleeping lock before completing stats */
 688                 if (d->lock)
 689                         spin_lock_bh(d->lock);
 690                 if (gnet_stats_copy_basic(d, NULL, &bstats, false) < 0 ||
 691                     gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
 692                         return -1;
 693         } else {
 694                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 695
 696                 sch = dev_queue->qdisc_sleeping;
 697                 if (gnet_stats_copy_basic(d, sch->cpu_bstats,
 698                                           &sch->bstats, true) < 0 ||
 699                     qdisc_qstats_copy(d, sch) < 0)
 700                         return -1;
 701         }
 702         return 0;
 703 }
 704
 705 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 706 {
 707         struct net_device *dev = qdisc_dev(sch);
 708         unsigned long ntx;
 709
 710         if (arg->stop)
 711                 return;
 712
 713         /* Walk hierarchy with a virtual class per tc */
 714         arg->count = arg->skip;
 715         for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
 716                 if (!tc_qdisc_stats_dump(sch, ntx + TC_H_MIN_PRIORITY, arg))
 717                         return;
 718         }
 719
 720         /* Pad the values and skip over unused traffic classes */
 721         if (ntx < TC_MAX_QUEUE) {
 722                 arg->count = TC_MAX_QUEUE;
 723                 ntx = TC_MAX_QUEUE;
 724         }
 725
 726         /* Reset offset, sort out remaining per-queue qdiscs */
 727         for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
 728                 if (arg->fn(sch, ntx + 1, arg) < 0) {
 729                         arg->stop = 1;
 730                         return;
 731                 }
 732                 arg->count++;
 733         }
 734 }
 735
 736 static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
 737                                                 struct tcmsg *tcm)
 738 {
 739         return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 740 }
 741
 742 static const struct Qdisc_class_ops mqprio_class_ops = {
 743         .graft          = mqprio_graft,
 744         .leaf           = mqprio_leaf,
 745         .find           = mqprio_find,
 746         .walk           = mqprio_walk,
 747         .dump           = mqprio_dump_class,
 748         .dump_stats     = mqprio_dump_class_stats,
 749         .select_queue   = mqprio_select_queue,
 750 };
 751
 752 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
 753         .cl_ops         = &mqprio_class_ops,
 754         .id             = "mqprio",
 755         .priv_size      = sizeof(struct mqprio_sched),
 756         .init           = mqprio_init,
 757         .destroy        = mqprio_destroy,
 758         .attach         = mqprio_attach,
 759         .change_real_num_tx = mq_change_real_num_tx,
 760         .dump           = mqprio_dump,
 761         .owner          = THIS_MODULE,
 762 };
 763
 764 static int __init mqprio_module_init(void)
 765 {
 766         return register_qdisc(&mqprio_qdisc_ops);
 767 }
 768
 769 static void __exit mqprio_module_exit(void)
 770 {
 771         unregister_qdisc(&mqprio_qdisc_ops);
 772 }
 773
 774 module_init(mqprio_module_init);
 775 module_exit(mqprio_module_exit);
 776
 777 MODULE_LICENSE("GPL");