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_type(n, TCA_MQPRIO_TC_ENTRY, nlattr_opt,
 219                                nlattr_opt_len, rem) {
 220                 err = mqprio_parse_tc_entry(fp, n, &seen_tcs, extack);
 221                 if (err)
 222                         goto out;
 223         }
 224
 225         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
 226                 priv->fp[tc] = fp[tc];
 227                 if (fp[tc] == TC_FP_PREEMPTIBLE)
 228                         have_preemption = true;
 229         }
 230
 231         if (have_preemption && !ethtool_dev_mm_supported(dev)) {
 232                 NL_SET_ERR_MSG(extack, "Device does not support preemption");
 233                 return -EOPNOTSUPP;
 234         }
 235 out:
 236         return err;
 237 }
 238
 239 /* Parse the other netlink attributes that represent the payload of
 240  * TCA_OPTIONS, which are appended right after struct tc_mqprio_qopt.
 241  */
 242 static int mqprio_parse_nlattr(struct Qdisc *sch, struct tc_mqprio_qopt *qopt,
 243                                struct nlattr *opt,
 244                                struct netlink_ext_ack *extack)
 245 {
 246         struct nlattr *nlattr_opt = nla_data(opt) + NLA_ALIGN(sizeof(*qopt));
 247         int nlattr_opt_len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 248         struct mqprio_sched *priv = qdisc_priv(sch);
 249         struct nlattr *tb[TCA_MQPRIO_MAX + 1] = {};
 250         struct nlattr *attr;
 251         int i, rem, err;
 252
 253         if (nlattr_opt_len >= nla_attr_size(0)) {
 254                 err = nla_parse_deprecated(tb, TCA_MQPRIO_MAX, nlattr_opt,
 255                                            nlattr_opt_len, mqprio_policy,
 256                                            NULL);
 257                 if (err < 0)
 258                         return err;
 259         }
 260
 261         if (!qopt->hw) {
 262                 NL_SET_ERR_MSG(extack,
 263                                "mqprio TCA_OPTIONS can only contain netlink attributes in hardware mode");
 264                 return -EINVAL;
 265         }
 266
 267         if (tb[TCA_MQPRIO_MODE]) {
 268                 priv->flags |= TC_MQPRIO_F_MODE;
 269                 priv->mode = nla_get_u16(tb[TCA_MQPRIO_MODE]);
 270         }
 271
 272         if (tb[TCA_MQPRIO_SHAPER]) {
 273                 priv->flags |= TC_MQPRIO_F_SHAPER;
 274                 priv->shaper = nla_get_u16(tb[TCA_MQPRIO_SHAPER]);
 275         }
 276
 277         if (tb[TCA_MQPRIO_MIN_RATE64]) {
 278                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 279                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MIN_RATE64],
 280                                             "min_rate accepted only when shaper is in bw_rlimit mode");
 281                         return -EINVAL;
 282                 }
 283                 i = 0;
 284                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
 285                                     rem) {
 286                         if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64) {
 287                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 288                                                     "Attribute type expected to be TCA_MQPRIO_MIN_RATE64");
 289                                 return -EINVAL;
 290                         }
 291
 292                         if (nla_len(attr) != sizeof(u64)) {
 293                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 294                                                     "Attribute TCA_MQPRIO_MIN_RATE64 expected to have 8 bytes length");
 295                                 return -EINVAL;
 296                         }
 297
 298                         if (i >= qopt->num_tc)
 299                                 break;
 300                         priv->min_rate[i] = nla_get_u64(attr);
 301                         i++;
 302                 }
 303                 priv->flags |= TC_MQPRIO_F_MIN_RATE;
 304         }
 305
 306         if (tb[TCA_MQPRIO_MAX_RATE64]) {
 307                 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
 308                         NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MAX_RATE64],
 309                                             "max_rate accepted only when shaper is in bw_rlimit mode");
 310                         return -EINVAL;
 311                 }
 312                 i = 0;
 313                 nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
 314                                     rem) {
 315                         if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64) {
 316                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 317                                                     "Attribute type expected to be TCA_MQPRIO_MAX_RATE64");
 318                                 return -EINVAL;
 319                         }
 320
 321                         if (nla_len(attr) != sizeof(u64)) {
 322                                 NL_SET_ERR_MSG_ATTR(extack, attr,
 323                                                     "Attribute TCA_MQPRIO_MAX_RATE64 expected to have 8 bytes length");
 324                                 return -EINVAL;
 325                         }
 326
 327                         if (i >= qopt->num_tc)
 328                                 break;
 329                         priv->max_rate[i] = nla_get_u64(attr);
 330                         i++;
 331                 }
 332                 priv->flags |= TC_MQPRIO_F_MAX_RATE;
 333         }
 334
 335         if (tb[TCA_MQPRIO_TC_ENTRY]) {
 336                 err = mqprio_parse_tc_entries(sch, nlattr_opt, nlattr_opt_len,
 337                                               extack);
 338                 if (err)
 339                         return err;
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 346                        struct netlink_ext_ack *extack)
 347 {
 348         struct net_device *dev = qdisc_dev(sch);
 349         struct mqprio_sched *priv = qdisc_priv(sch);
 350         struct netdev_queue *dev_queue;
 351         struct Qdisc *qdisc;
 352         int i, err = -EOPNOTSUPP;
 353         struct tc_mqprio_qopt *qopt = NULL;
 354         struct tc_mqprio_caps caps;
 355         int len, tc;
 356
 357         BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
 358         BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
 359
 360         if (sch->parent != TC_H_ROOT)
 361                 return -EOPNOTSUPP;
 362
 363         if (!netif_is_multiqueue(dev))
 364                 return -EOPNOTSUPP;
 365
 366         /* make certain can allocate enough classids to handle queues */
 367         if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
 368                 return -ENOMEM;
 369
 370         if (!opt || nla_len(opt) < sizeof(*qopt))
 371                 return -EINVAL;
 372
 373         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
 374                 priv->fp[tc] = TC_FP_EXPRESS;
 375
 376         qdisc_offload_query_caps(dev, TC_SETUP_QDISC_MQPRIO,
 377                                  &caps, sizeof(caps));
 378
 379         qopt = nla_data(opt);
 380         if (mqprio_parse_opt(dev, qopt, &caps, extack))
 381                 return -EINVAL;
 382
 383         len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
 384         if (len > 0) {
 385                 err = mqprio_parse_nlattr(sch, qopt, opt, extack);
 386                 if (err)
 387                         return err;
 388         }
 389
 390         /* pre-allocate qdisc, attachment can't fail */
 391         priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
 392                                GFP_KERNEL);
 393         if (!priv->qdiscs)
 394                 return -ENOMEM;
 395
 396         for (i = 0; i < dev->num_tx_queues; i++) {
 397                 dev_queue = netdev_get_tx_queue(dev, i);
 398                 qdisc = qdisc_create_dflt(dev_queue,
 399                                           get_default_qdisc_ops(dev, i),
 400                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
 401                                                     TC_H_MIN(i + 1)), extack);
 402                 if (!qdisc)
 403                         return -ENOMEM;
 404
 405                 priv->qdiscs[i] = qdisc;
 406                 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 407         }
 408
 409         /* If the mqprio options indicate that hardware should own
 410          * the queue mapping then run ndo_setup_tc otherwise use the
 411          * supplied and verified mapping
 412          */
 413         if (qopt->hw) {
 414                 err = mqprio_enable_offload(sch, qopt, extack);
 415                 if (err)
 416                         return err;
 417         } else {
 418                 netdev_set_num_tc(dev, qopt->num_tc);
 419                 for (i = 0; i < qopt->num_tc; i++)
 420                         netdev_set_tc_queue(dev, i,
 421                                             qopt->count[i], qopt->offset[i]);
 422         }
 423
 424         /* Always use supplied priority mappings */
 425         for (i = 0; i < TC_BITMASK + 1; i++)
 426                 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
 427
 428         sch->flags |= TCQ_F_MQROOT;
 429         return 0;
 430 }
 431
 432 static void mqprio_attach(struct Qdisc *sch)
 433 {
 434         struct net_device *dev = qdisc_dev(sch);
 435         struct mqprio_sched *priv = qdisc_priv(sch);
 436         struct Qdisc *qdisc, *old;
 437         unsigned int ntx;
 438
 439         /* Attach underlying qdisc */
 440         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 441                 qdisc = priv->qdiscs[ntx];
 442                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
 443                 if (old)
 444                         qdisc_put(old);
 445                 if (ntx < dev->real_num_tx_queues)
 446                         qdisc_hash_add(qdisc, false);
 447         }
 448         kfree(priv->qdiscs);
 449         priv->qdiscs = NULL;
 450 }
 451
 452 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
 453                                              unsigned long cl)
 454 {
 455         struct net_device *dev = qdisc_dev(sch);
 456         unsigned long ntx = cl - 1;
 457
 458         if (ntx >= dev->num_tx_queues)
 459                 return NULL;
 460         return netdev_get_tx_queue(dev, ntx);
 461 }
 462
 463 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
 464                         struct Qdisc **old, struct netlink_ext_ack *extack)
 465 {
 466         struct net_device *dev = qdisc_dev(sch);
 467         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 468
 469         if (!dev_queue)
 470                 return -EINVAL;
 471
 472         if (dev->flags & IFF_UP)
 473                 dev_deactivate(dev);
 474
 475         *old = dev_graft_qdisc(dev_queue, new);
 476
 477         if (new)
 478                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
 479
 480         if (dev->flags & IFF_UP)
 481                 dev_activate(dev);
 482
 483         return 0;
 484 }
 485
 486 static int dump_rates(struct mqprio_sched *priv,
 487                       struct tc_mqprio_qopt *opt, struct sk_buff *skb)
 488 {
 489         struct nlattr *nest;
 490         int i;
 491
 492         if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
 493                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MIN_RATE64);
 494                 if (!nest)
 495                         goto nla_put_failure;
 496
 497                 for (i = 0; i < opt->num_tc; i++) {
 498                         if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
 499                                     sizeof(priv->min_rate[i]),
 500                                     &priv->min_rate[i]))
 501                                 goto nla_put_failure;
 502                 }
 503                 nla_nest_end(skb, nest);
 504         }
 505
 506         if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
 507                 nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MAX_RATE64);
 508                 if (!nest)
 509                         goto nla_put_failure;
 510
 511                 for (i = 0; i < opt->num_tc; i++) {
 512                         if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
 513                                     sizeof(priv->max_rate[i]),
 514                                     &priv->max_rate[i]))
 515                                 goto nla_put_failure;
 516                 }
 517                 nla_nest_end(skb, nest);
 518         }
 519         return 0;
 520
 521 nla_put_failure:
 522         nla_nest_cancel(skb, nest);
 523         return -1;
 524 }
 525
 526 static int mqprio_dump_tc_entries(struct mqprio_sched *priv,
 527                                   struct sk_buff *skb)
 528 {
 529         struct nlattr *n;
 530         int tc;
 531
 532         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
 533                 n = nla_nest_start(skb, TCA_MQPRIO_TC_ENTRY);
 534                 if (!n)
 535                         return -EMSGSIZE;
 536
 537                 if (nla_put_u32(skb, TCA_MQPRIO_TC_ENTRY_INDEX, tc))
 538                         goto nla_put_failure;
 539
 540                 if (nla_put_u32(skb, TCA_MQPRIO_TC_ENTRY_FP, priv->fp[tc]))
 541                         goto nla_put_failure;
 542
 543                 nla_nest_end(skb, n);
 544         }
 545
 546         return 0;
 547
 548 nla_put_failure:
 549         nla_nest_cancel(skb, n);
 550         return -EMSGSIZE;
 551 }
 552
 553 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
 554 {
 555         struct net_device *dev = qdisc_dev(sch);
 556         struct mqprio_sched *priv = qdisc_priv(sch);
 557         struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
 558         struct tc_mqprio_qopt opt = { 0 };
 559         struct Qdisc *qdisc;
 560         unsigned int ntx;
 561
 562         sch->q.qlen = 0;
 563         gnet_stats_basic_sync_init(&sch->bstats);
 564         memset(&sch->qstats, 0, sizeof(sch->qstats));
 565
 566         /* MQ supports lockless qdiscs. However, statistics accounting needs
 567          * to account for all, none, or a mix of locked and unlocked child
 568          * qdiscs. Percpu stats are added to counters in-band and locking
 569          * qdisc totals are added at end.
 570          */
 571         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
 572                 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping);
 573                 spin_lock_bh(qdisc_lock(qdisc));
 574
 575                 gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats,
 576                                      &qdisc->bstats, false);
 577                 gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats,
 578                                      &qdisc->qstats);
 579                 sch->q.qlen += qdisc_qlen(qdisc);
 580
 581                 spin_unlock_bh(qdisc_lock(qdisc));
 582         }
 583
 584         mqprio_qopt_reconstruct(dev, &opt);
 585         opt.hw = priv->hw_offload;
 586
 587         if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 588                 goto nla_put_failure;
 589
 590         if ((priv->flags & TC_MQPRIO_F_MODE) &&
 591             nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
 592                 goto nla_put_failure;
 593
 594         if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
 595             nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
 596                 goto nla_put_failure;
 597
 598         if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
 599              priv->flags & TC_MQPRIO_F_MAX_RATE) &&
 600             (dump_rates(priv, &opt, skb) != 0))
 601                 goto nla_put_failure;
 602
 603         if (mqprio_dump_tc_entries(priv, skb))
 604                 goto nla_put_failure;
 605
 606         return nla_nest_end(skb, nla);
 607 nla_put_failure:
 608         nlmsg_trim(skb, nla);
 609         return -1;
 610 }
 611
 612 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
 613 {
 614         struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 615
 616         if (!dev_queue)
 617                 return NULL;
 618
 619         return rtnl_dereference(dev_queue->qdisc_sleeping);
 620 }
 621
 622 static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
 623 {
 624         struct net_device *dev = qdisc_dev(sch);
 625         unsigned int ntx = TC_H_MIN(classid);
 626
 627         /* There are essentially two regions here that have valid classid
 628          * values. The first region will have a classid value of 1 through
 629          * num_tx_queues. All of these are backed by actual Qdiscs.
 630          */
 631         if (ntx < TC_H_MIN_PRIORITY)
 632                 return (ntx <= dev->num_tx_queues) ? ntx : 0;
 633
 634         /* The second region represents the hardware traffic classes. These
 635          * are represented by classid values of TC_H_MIN_PRIORITY through
 636          * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
 637          */
 638         return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
 639 }
 640
 641 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
 642                          struct sk_buff *skb, struct tcmsg *tcm)
 643 {
 644         if (cl < TC_H_MIN_PRIORITY) {
 645                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 646                 struct net_device *dev = qdisc_dev(sch);
 647                 int tc = netdev_txq_to_tc(dev, cl - 1);
 648
 649                 tcm->tcm_parent = (tc < 0) ? 0 :
 650                         TC_H_MAKE(TC_H_MAJ(sch->handle),
 651                                   TC_H_MIN(tc + TC_H_MIN_PRIORITY));
 652                 tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle;
 653         } else {
 654                 tcm->tcm_parent = TC_H_ROOT;
 655                 tcm->tcm_info = 0;
 656         }
 657         tcm->tcm_handle |= TC_H_MIN(cl);
 658         return 0;
 659 }
 660
 661 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 662                                    struct gnet_dump *d)
 663         __releases(d->lock)
 664         __acquires(d->lock)
 665 {
 666         if (cl >= TC_H_MIN_PRIORITY) {
 667                 int i;
 668                 __u32 qlen;
 669                 struct gnet_stats_queue qstats = {0};
 670                 struct gnet_stats_basic_sync bstats;
 671                 struct net_device *dev = qdisc_dev(sch);
 672                 struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
 673
 674                 gnet_stats_basic_sync_init(&bstats);
 675                 /* Drop lock here it will be reclaimed before touching
 676                  * statistics this is required because the d->lock we
 677                  * hold here is the look on dev_queue->qdisc_sleeping
 678                  * also acquired below.
 679                  */
 680                 if (d->lock)
 681                         spin_unlock_bh(d->lock);
 682
 683                 for (i = tc.offset; i < tc.offset + tc.count; i++) {
 684                         struct netdev_queue *q = netdev_get_tx_queue(dev, i);
 685                         struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
 686
 687                         spin_lock_bh(qdisc_lock(qdisc));
 688
 689                         gnet_stats_add_basic(&bstats, qdisc->cpu_bstats,
 690                                              &qdisc->bstats, false);
 691                         gnet_stats_add_queue(&qstats, qdisc->cpu_qstats,
 692                                              &qdisc->qstats);
 693                         sch->q.qlen += qdisc_qlen(qdisc);
 694
 695                         spin_unlock_bh(qdisc_lock(qdisc));
 696                 }
 697                 qlen = qdisc_qlen(sch) + qstats.qlen;
 698
 699                 /* Reclaim root sleeping lock before completing stats */
 700                 if (d->lock)
 701                         spin_lock_bh(d->lock);
 702                 if (gnet_stats_copy_basic(d, NULL, &bstats, false) < 0 ||
 703                     gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
 704                         return -1;
 705         } else {
 706                 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
 707
 708                 sch = rtnl_dereference(dev_queue->qdisc_sleeping);
 709                 if (gnet_stats_copy_basic(d, sch->cpu_bstats,
 710                                           &sch->bstats, true) < 0 ||
 711                     qdisc_qstats_copy(d, sch) < 0)
 712                         return -1;
 713         }
 714         return 0;
 715 }
 716
 717 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 718 {
 719         struct net_device *dev = qdisc_dev(sch);
 720         unsigned long ntx;
 721
 722         if (arg->stop)
 723                 return;
 724
 725         /* Walk hierarchy with a virtual class per tc */
 726         arg->count = arg->skip;
 727         for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
 728                 if (!tc_qdisc_stats_dump(sch, ntx + TC_H_MIN_PRIORITY, arg))
 729                         return;
 730         }
 731
 732         /* Pad the values and skip over unused traffic classes */
 733         if (ntx < TC_MAX_QUEUE) {
 734                 arg->count = TC_MAX_QUEUE;
 735                 ntx = TC_MAX_QUEUE;
 736         }
 737
 738         /* Reset offset, sort out remaining per-queue qdiscs */
 739         for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
 740                 if (arg->fn(sch, ntx + 1, arg) < 0) {
 741                         arg->stop = 1;
 742                         return;
 743                 }
 744                 arg->count++;
 745         }
 746 }
 747
 748 static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
 749                                                 struct tcmsg *tcm)
 750 {
 751         return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 752 }
 753
 754 static const struct Qdisc_class_ops mqprio_class_ops = {
 755         .graft          = mqprio_graft,
 756         .leaf           = mqprio_leaf,
 757         .find           = mqprio_find,
 758         .walk           = mqprio_walk,
 759         .dump           = mqprio_dump_class,
 760         .dump_stats     = mqprio_dump_class_stats,
 761         .select_queue   = mqprio_select_queue,
 762 };
 763
 764 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
 765         .cl_ops         = &mqprio_class_ops,
 766         .id             = "mqprio",
 767         .priv_size      = sizeof(struct mqprio_sched),
 768         .init           = mqprio_init,
 769         .destroy        = mqprio_destroy,
 770         .attach         = mqprio_attach,
 771         .change_real_num_tx = mq_change_real_num_tx,
 772         .dump           = mqprio_dump,
 773         .owner          = THIS_MODULE,
 774 };
 775 MODULE_ALIAS_NET_SCH("mqprio");
 776
 777 static int __init mqprio_module_init(void)
 778 {
 779         return register_qdisc(&mqprio_qdisc_ops);
 780 }
 781
 782 static void __exit mqprio_module_exit(void)
 783 {
 784         unregister_qdisc(&mqprio_qdisc_ops);
 785 }
 786
 787 module_init(mqprio_module_init);
 788 module_exit(mqprio_module_exit);
 789
 790 MODULE_LICENSE("GPL");
 791 MODULE_DESCRIPTION("Classful multiqueue prio qdisc");