net/sched/sch_taprio.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* net/sched/sch_taprio.c        Time Aware Priority Scheduler
   4  *
   5  * Authors:     Vinicius Costa Gomes <vinicius.gomes@intel.com>
   6  *
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/list.h>
  14 #include <linux/errno.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/math64.h>
  17 #include <linux/module.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/rcupdate.h>
  20 #include <net/netlink.h>
  21 #include <net/pkt_sched.h>
  22 #include <net/pkt_cls.h>
  23 #include <net/sch_generic.h>
  24 #include <net/sock.h>
  25 #include <net/tcp.h>
  26
  27 static LIST_HEAD(taprio_list);
  28 static DEFINE_SPINLOCK(taprio_list_lock);
  29
  30 #define TAPRIO_ALL_GATES_OPEN -1
  31
  32 #define FLAGS_VALID(flags) (!((flags) & ~TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST))
  33 #define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST)
  34
  35 struct sched_entry {
  36         struct list_head list;
  37
  38         /* The instant that this entry "closes" and the next one
  39          * should open, the qdisc will make some effort so that no
  40          * packet leaves after this time.
  41          */
  42         ktime_t close_time;
  43         ktime_t next_txtime;
  44         atomic_t budget;
  45         int index;
  46         u32 gate_mask;
  47         u32 interval;
  48         u8 command;
  49 };
  50
  51 struct sched_gate_list {
  52         struct rcu_head rcu;
  53         struct list_head entries;
  54         size_t num_entries;
  55         ktime_t cycle_close_time;
  56         s64 cycle_time;
  57         s64 cycle_time_extension;
  58         s64 base_time;
  59 };
  60
  61 struct taprio_sched {
  62         struct Qdisc **qdiscs;
  63         struct Qdisc *root;
  64         u32 flags;
  65         enum tk_offsets tk_offset;
  66         int clockid;
  67         atomic64_t picos_per_byte; /* Using picoseconds because for 10Gbps+
  68                                     * speeds it's sub-nanoseconds per byte
  69                                     */
  70
  71         /* Protects the update side of the RCU protected current_entry */
  72         spinlock_t current_entry_lock;
  73         struct sched_entry __rcu *current_entry;
  74         struct sched_gate_list __rcu *oper_sched;
  75         struct sched_gate_list __rcu *admin_sched;
  76         struct hrtimer advance_timer;
  77         struct list_head taprio_list;
  78         u32 txtime_delay;
  79 };
  80
  81 static ktime_t sched_base_time(const struct sched_gate_list *sched)
  82 {
  83         if (!sched)
  84                 return KTIME_MAX;
  85
  86         return ns_to_ktime(sched->base_time);
  87 }
  88
  89 static ktime_t taprio_get_time(struct taprio_sched *q)
  90 {
  91         ktime_t mono = ktime_get();
  92
  93         switch (q->tk_offset) {
  94         case TK_OFFS_MAX:
  95                 return mono;
  96         default:
  97                 return ktime_mono_to_any(mono, q->tk_offset);
  98         }
  99
 100         return KTIME_MAX;
 101 }
 102
 103 static void taprio_free_sched_cb(struct rcu_head *head)
 104 {
 105         struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
 106         struct sched_entry *entry, *n;
 107
 108         if (!sched)
 109                 return;
 110
 111         list_for_each_entry_safe(entry, n, &sched->entries, list) {
 112                 list_del(&entry->list);
 113                 kfree(entry);
 114         }
 115
 116         kfree(sched);
 117 }
 118
 119 static void switch_schedules(struct taprio_sched *q,
 120                              struct sched_gate_list **admin,
 121                              struct sched_gate_list **oper)
 122 {
 123         rcu_assign_pointer(q->oper_sched, *admin);
 124         rcu_assign_pointer(q->admin_sched, NULL);
 125
 126         if (*oper)
 127                 call_rcu(&(*oper)->rcu, taprio_free_sched_cb);
 128
 129         *oper = *admin;
 130         *admin = NULL;
 131 }
 132
 133 /* Get how much time has been already elapsed in the current cycle. */
 134 static s32 get_cycle_time_elapsed(struct sched_gate_list *sched, ktime_t time)
 135 {
 136         ktime_t time_since_sched_start;
 137         s32 time_elapsed;
 138
 139         time_since_sched_start = ktime_sub(time, sched->base_time);
 140         div_s64_rem(time_since_sched_start, sched->cycle_time, &time_elapsed);
 141
 142         return time_elapsed;
 143 }
 144
 145 static ktime_t get_interval_end_time(struct sched_gate_list *sched,
 146                                      struct sched_gate_list *admin,
 147                                      struct sched_entry *entry,
 148                                      ktime_t intv_start)
 149 {
 150         s32 cycle_elapsed = get_cycle_time_elapsed(sched, intv_start);
 151         ktime_t intv_end, cycle_ext_end, cycle_end;
 152
 153         cycle_end = ktime_add_ns(intv_start, sched->cycle_time - cycle_elapsed);
 154         intv_end = ktime_add_ns(intv_start, entry->interval);
 155         cycle_ext_end = ktime_add(cycle_end, sched->cycle_time_extension);
 156
 157         if (ktime_before(intv_end, cycle_end))
 158                 return intv_end;
 159         else if (admin && admin != sched &&
 160                  ktime_after(admin->base_time, cycle_end) &&
 161                  ktime_before(admin->base_time, cycle_ext_end))
 162                 return admin->base_time;
 163         else
 164                 return cycle_end;
 165 }
 166
 167 static int length_to_duration(struct taprio_sched *q, int len)
 168 {
 169         return div_u64(len * atomic64_read(&q->picos_per_byte), 1000);
 170 }
 171
 172 /* Returns the entry corresponding to next available interval. If
 173  * validate_interval is set, it only validates whether the timestamp occurs
 174  * when the gate corresponding to the skb's traffic class is open.
 175  */
 176 static struct sched_entry *find_entry_to_transmit(struct sk_buff *skb,
 177                                                   struct Qdisc *sch,
 178                                                   struct sched_gate_list *sched,
 179                                                   struct sched_gate_list *admin,
 180                                                   ktime_t time,
 181                                                   ktime_t *interval_start,
 182                                                   ktime_t *interval_end,
 183                                                   bool validate_interval)
 184 {
 185         ktime_t curr_intv_start, curr_intv_end, cycle_end, packet_transmit_time;
 186         ktime_t earliest_txtime = KTIME_MAX, txtime, cycle, transmit_end_time;
 187         struct sched_entry *entry = NULL, *entry_found = NULL;
 188         struct taprio_sched *q = qdisc_priv(sch);
 189         struct net_device *dev = qdisc_dev(sch);
 190         bool entry_available = false;
 191         s32 cycle_elapsed;
 192         int tc, n;
 193
 194         tc = netdev_get_prio_tc_map(dev, skb->priority);
 195         packet_transmit_time = length_to_duration(q, qdisc_pkt_len(skb));
 196
 197         *interval_start = 0;
 198         *interval_end = 0;
 199
 200         if (!sched)
 201                 return NULL;
 202
 203         cycle = sched->cycle_time;
 204         cycle_elapsed = get_cycle_time_elapsed(sched, time);
 205         curr_intv_end = ktime_sub_ns(time, cycle_elapsed);
 206         cycle_end = ktime_add_ns(curr_intv_end, cycle);
 207
 208         list_for_each_entry(entry, &sched->entries, list) {
 209                 curr_intv_start = curr_intv_end;
 210                 curr_intv_end = get_interval_end_time(sched, admin, entry,
 211                                                       curr_intv_start);
 212
 213                 if (ktime_after(curr_intv_start, cycle_end))
 214                         break;
 215
 216                 if (!(entry->gate_mask & BIT(tc)) ||
 217                     packet_transmit_time > entry->interval)
 218                         continue;
 219
 220                 txtime = entry->next_txtime;
 221
 222                 if (ktime_before(txtime, time) || validate_interval) {
 223                         transmit_end_time = ktime_add_ns(time, packet_transmit_time);
 224                         if ((ktime_before(curr_intv_start, time) &&
 225                              ktime_before(transmit_end_time, curr_intv_end)) ||
 226                             (ktime_after(curr_intv_start, time) && !validate_interval)) {
 227                                 entry_found = entry;
 228                                 *interval_start = curr_intv_start;
 229                                 *interval_end = curr_intv_end;
 230                                 break;
 231                         } else if (!entry_available && !validate_interval) {
 232                                 /* Here, we are just trying to find out the
 233                                  * first available interval in the next cycle.
 234                                  */
 235                                 entry_available = 1;
 236                                 entry_found = entry;
 237                                 *interval_start = ktime_add_ns(curr_intv_start, cycle);
 238                                 *interval_end = ktime_add_ns(curr_intv_end, cycle);
 239                         }
 240                 } else if (ktime_before(txtime, earliest_txtime) &&
 241                            !entry_available) {
 242                         earliest_txtime = txtime;
 243                         entry_found = entry;
 244                         n = div_s64(ktime_sub(txtime, curr_intv_start), cycle);
 245                         *interval_start = ktime_add(curr_intv_start, n * cycle);
 246                         *interval_end = ktime_add(curr_intv_end, n * cycle);
 247                 }
 248         }
 249
 250         return entry_found;
 251 }
 252
 253 static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
 254 {
 255         struct taprio_sched *q = qdisc_priv(sch);
 256         struct sched_gate_list *sched, *admin;
 257         ktime_t interval_start, interval_end;
 258         struct sched_entry *entry;
 259
 260         rcu_read_lock();
 261         sched = rcu_dereference(q->oper_sched);
 262         admin = rcu_dereference(q->admin_sched);
 263
 264         entry = find_entry_to_transmit(skb, sch, sched, admin, skb->tstamp,
 265                                        &interval_start, &interval_end, true);
 266         rcu_read_unlock();
 267
 268         return entry;
 269 }
 270
 271 /* This returns the tstamp value set by TCP in terms of the set clock. */
 272 static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
 273 {
 274         unsigned int offset = skb_network_offset(skb);
 275         const struct ipv6hdr *ipv6h;
 276         const struct iphdr *iph;
 277         struct ipv6hdr _ipv6h;
 278
 279         ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
 280         if (!ipv6h)
 281                 return 0;
 282
 283         if (ipv6h->version == 4) {
 284                 iph = (struct iphdr *)ipv6h;
 285                 offset += iph->ihl * 4;
 286
 287                 /* special-case 6in4 tunnelling, as that is a common way to get
 288                  * v6 connectivity in the home
 289                  */
 290                 if (iph->protocol == IPPROTO_IPV6) {
 291                         ipv6h = skb_header_pointer(skb, offset,
 292                                                    sizeof(_ipv6h), &_ipv6h);
 293
 294                         if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
 295                                 return 0;
 296                 } else if (iph->protocol != IPPROTO_TCP) {
 297                         return 0;
 298                 }
 299         } else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
 300                 return 0;
 301         }
 302
 303         return ktime_mono_to_any(skb->skb_mstamp_ns, q->tk_offset);
 304 }
 305
 306 /* There are a few scenarios where we will have to modify the txtime from
 307  * what is read from next_txtime in sched_entry. They are:
 308  * 1. If txtime is in the past,
 309  *    a. The gate for the traffic class is currently open and packet can be
 310  *       transmitted before it closes, schedule the packet right away.
 311  *    b. If the gate corresponding to the traffic class is going to open later
 312  *       in the cycle, set the txtime of packet to the interval start.
 313  * 2. If txtime is in the future, there are packets corresponding to the
 314  *    current traffic class waiting to be transmitted. So, the following
 315  *    possibilities exist:
 316  *    a. We can transmit the packet before the window containing the txtime
 317  *       closes.
 318  *    b. The window might close before the transmission can be completed
 319  *       successfully. So, schedule the packet in the next open window.
 320  */
 321 static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 322 {
 323         ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
 324         struct taprio_sched *q = qdisc_priv(sch);
 325         struct sched_gate_list *sched, *admin;
 326         ktime_t minimum_time, now, txtime;
 327         int len, packet_transmit_time;
 328         struct sched_entry *entry;
 329         bool sched_changed;
 330
 331         now = taprio_get_time(q);
 332         minimum_time = ktime_add_ns(now, q->txtime_delay);
 333
 334         tcp_tstamp = get_tcp_tstamp(q, skb);
 335         minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
 336
 337         rcu_read_lock();
 338         admin = rcu_dereference(q->admin_sched);
 339         sched = rcu_dereference(q->oper_sched);
 340         if (admin && ktime_after(minimum_time, admin->base_time))
 341                 switch_schedules(q, &admin, &sched);
 342
 343         /* Until the schedule starts, all the queues are open */
 344         if (!sched || ktime_before(minimum_time, sched->base_time)) {
 345                 txtime = minimum_time;
 346                 goto done;
 347         }
 348
 349         len = qdisc_pkt_len(skb);
 350         packet_transmit_time = length_to_duration(q, len);
 351
 352         do {
 353                 sched_changed = 0;
 354
 355                 entry = find_entry_to_transmit(skb, sch, sched, admin,
 356                                                minimum_time,
 357                                                &interval_start, &interval_end,
 358                                                false);
 359                 if (!entry) {
 360                         txtime = 0;
 361                         goto done;
 362                 }
 363
 364                 txtime = entry->next_txtime;
 365                 txtime = max_t(ktime_t, txtime, minimum_time);
 366                 txtime = max_t(ktime_t, txtime, interval_start);
 367
 368                 if (admin && admin != sched &&
 369                     ktime_after(txtime, admin->base_time)) {
 370                         sched = admin;
 371                         sched_changed = 1;
 372                         continue;
 373                 }
 374
 375                 transmit_end_time = ktime_add(txtime, packet_transmit_time);
 376                 minimum_time = transmit_end_time;
 377
 378                 /* Update the txtime of current entry to the next time it's
 379                  * interval starts.
 380                  */
 381                 if (ktime_after(transmit_end_time, interval_end))
 382                         entry->next_txtime = ktime_add(interval_start, sched->cycle_time);
 383         } while (sched_changed || ktime_after(transmit_end_time, interval_end));
 384
 385         entry->next_txtime = transmit_end_time;
 386
 387 done:
 388         rcu_read_unlock();
 389         return txtime;
 390 }
 391
 392 static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 393                           struct sk_buff **to_free)
 394 {
 395         struct taprio_sched *q = qdisc_priv(sch);
 396         struct Qdisc *child;
 397         int queue;
 398
 399         queue = skb_get_queue_mapping(skb);
 400
 401         child = q->qdiscs[queue];
 402         if (unlikely(!child))
 403                 return qdisc_drop(skb, sch, to_free);
 404
 405         if (skb->sk && sock_flag(skb->sk, SOCK_TXTIME)) {
 406                 if (!is_valid_interval(skb, sch))
 407                         return qdisc_drop(skb, sch, to_free);
 408         } else if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 409                 skb->tstamp = get_packet_txtime(skb, sch);
 410                 if (!skb->tstamp)
 411                         return qdisc_drop(skb, sch, to_free);
 412         }
 413
 414         qdisc_qstats_backlog_inc(sch, skb);
 415         sch->q.qlen++;
 416
 417         return qdisc_enqueue(skb, child, to_free);
 418 }
 419
 420 static struct sk_buff *taprio_peek(struct Qdisc *sch)
 421 {
 422         struct taprio_sched *q = qdisc_priv(sch);
 423         struct net_device *dev = qdisc_dev(sch);
 424         struct sched_entry *entry;
 425         struct sk_buff *skb;
 426         u32 gate_mask;
 427         int i;
 428
 429         rcu_read_lock();
 430         entry = rcu_dereference(q->current_entry);
 431         gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 432         rcu_read_unlock();
 433
 434         if (!gate_mask)
 435                 return NULL;
 436
 437         for (i = 0; i < dev->num_tx_queues; i++) {
 438                 struct Qdisc *child = q->qdiscs[i];
 439                 int prio;
 440                 u8 tc;
 441
 442                 if (unlikely(!child))
 443                         continue;
 444
 445                 skb = child->ops->peek(child);
 446                 if (!skb)
 447                         continue;
 448
 449                 if (TXTIME_ASSIST_IS_ENABLED(q->flags))
 450                         return skb;
 451
 452                 prio = skb->priority;
 453                 tc = netdev_get_prio_tc_map(dev, prio);
 454
 455                 if (!(gate_mask & BIT(tc)))
 456                         continue;
 457
 458                 return skb;
 459         }
 460
 461         return NULL;
 462 }
 463
 464 static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry)
 465 {
 466         atomic_set(&entry->budget,
 467                    div64_u64((u64)entry->interval * 1000,
 468                              atomic64_read(&q->picos_per_byte)));
 469 }
 470
 471 static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 472 {
 473         struct taprio_sched *q = qdisc_priv(sch);
 474         struct net_device *dev = qdisc_dev(sch);
 475         struct sk_buff *skb = NULL;
 476         struct sched_entry *entry;
 477         u32 gate_mask;
 478         int i;
 479
 480         rcu_read_lock();
 481         entry = rcu_dereference(q->current_entry);
 482         /* if there's no entry, it means that the schedule didn't
 483          * start yet, so force all gates to be open, this is in
 484          * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5
 485          * "AdminGateSates"
 486          */
 487         gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 488
 489         if (!gate_mask)
 490                 goto done;
 491
 492         for (i = 0; i < dev->num_tx_queues; i++) {
 493                 struct Qdisc *child = q->qdiscs[i];
 494                 ktime_t guard;
 495                 int prio;
 496                 int len;
 497                 u8 tc;
 498
 499                 if (unlikely(!child))
 500                         continue;
 501
 502                 if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 503                         skb = child->ops->dequeue(child);
 504                         if (!skb)
 505                                 continue;
 506                         goto skb_found;
 507                 }
 508
 509                 skb = child->ops->peek(child);
 510                 if (!skb)
 511                         continue;
 512
 513                 prio = skb->priority;
 514                 tc = netdev_get_prio_tc_map(dev, prio);
 515
 516                 if (!(gate_mask & BIT(tc)))
 517                         continue;
 518
 519                 len = qdisc_pkt_len(skb);
 520                 guard = ktime_add_ns(taprio_get_time(q),
 521                                      length_to_duration(q, len));
 522
 523                 /* In the case that there's no gate entry, there's no
 524                  * guard band ...
 525                  */
 526                 if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 527                     ktime_after(guard, entry->close_time))
 528                         continue;
 529
 530                 /* ... and no budget. */
 531                 if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 532                     atomic_sub_return(len, &entry->budget) < 0)
 533                         continue;
 534
 535                 skb = child->ops->dequeue(child);
 536                 if (unlikely(!skb))
 537                         goto done;
 538
 539 skb_found:
 540                 qdisc_bstats_update(sch, skb);
 541                 qdisc_qstats_backlog_dec(sch, skb);
 542                 sch->q.qlen--;
 543
 544                 goto done;
 545         }
 546
 547 done:
 548         rcu_read_unlock();
 549
 550         return skb;
 551 }
 552
 553 static bool should_restart_cycle(const struct sched_gate_list *oper,
 554                                  const struct sched_entry *entry)
 555 {
 556         if (list_is_last(&entry->list, &oper->entries))
 557                 return true;
 558
 559         if (ktime_compare(entry->close_time, oper->cycle_close_time) == 0)
 560                 return true;
 561
 562         return false;
 563 }
 564
 565 static bool should_change_schedules(const struct sched_gate_list *admin,
 566                                     const struct sched_gate_list *oper,
 567                                     ktime_t close_time)
 568 {
 569         ktime_t next_base_time, extension_time;
 570
 571         if (!admin)
 572                 return false;
 573
 574         next_base_time = sched_base_time(admin);
 575
 576         /* This is the simple case, the close_time would fall after
 577          * the next schedule base_time.
 578          */
 579         if (ktime_compare(next_base_time, close_time) <= 0)
 580                 return true;
 581
 582         /* This is the cycle_time_extension case, if the close_time
 583          * plus the amount that can be extended would fall after the
 584          * next schedule base_time, we can extend the current schedule
 585          * for that amount.
 586          */
 587         extension_time = ktime_add_ns(close_time, oper->cycle_time_extension);
 588
 589         /* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about
 590          * how precisely the extension should be made. So after
 591          * conformance testing, this logic may change.
 592          */
 593         if (ktime_compare(next_base_time, extension_time) <= 0)
 594                 return true;
 595
 596         return false;
 597 }
 598
 599 static enum hrtimer_restart advance_sched(struct hrtimer *timer)
 600 {
 601         struct taprio_sched *q = container_of(timer, struct taprio_sched,
 602                                               advance_timer);
 603         struct sched_gate_list *oper, *admin;
 604         struct sched_entry *entry, *next;
 605         struct Qdisc *sch = q->root;
 606         ktime_t close_time;
 607
 608         spin_lock(&q->current_entry_lock);
 609         entry = rcu_dereference_protected(q->current_entry,
 610                                           lockdep_is_held(&q->current_entry_lock));
 611         oper = rcu_dereference_protected(q->oper_sched,
 612                                          lockdep_is_held(&q->current_entry_lock));
 613         admin = rcu_dereference_protected(q->admin_sched,
 614                                           lockdep_is_held(&q->current_entry_lock));
 615
 616         if (!oper)
 617                 switch_schedules(q, &admin, &oper);
 618
 619         /* This can happen in two cases: 1. this is the very first run
 620          * of this function (i.e. we weren't running any schedule
 621          * previously); 2. The previous schedule just ended. The first
 622          * entry of all schedules are pre-calculated during the
 623          * schedule initialization.
 624          */
 625         if (unlikely(!entry || entry->close_time == oper->base_time)) {
 626                 next = list_first_entry(&oper->entries, struct sched_entry,
 627                                         list);
 628                 close_time = next->close_time;
 629                 goto first_run;
 630         }
 631
 632         if (should_restart_cycle(oper, entry)) {
 633                 next = list_first_entry(&oper->entries, struct sched_entry,
 634                                         list);
 635                 oper->cycle_close_time = ktime_add_ns(oper->cycle_close_time,
 636                                                       oper->cycle_time);
 637         } else {
 638                 next = list_next_entry(entry, list);
 639         }
 640
 641         close_time = ktime_add_ns(entry->close_time, next->interval);
 642         close_time = min_t(ktime_t, close_time, oper->cycle_close_time);
 643
 644         if (should_change_schedules(admin, oper, close_time)) {
 645                 /* Set things so the next time this runs, the new
 646                  * schedule runs.
 647                  */
 648                 close_time = sched_base_time(admin);
 649                 switch_schedules(q, &admin, &oper);
 650         }
 651
 652         next->close_time = close_time;
 653         taprio_set_budget(q, next);
 654
 655 first_run:
 656         rcu_assign_pointer(q->current_entry, next);
 657         spin_unlock(&q->current_entry_lock);
 658
 659         hrtimer_set_expires(&q->advance_timer, close_time);
 660
 661         rcu_read_lock();
 662         __netif_schedule(sch);
 663         rcu_read_unlock();
 664
 665         return HRTIMER_RESTART;
 666 }
 667
 668 static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = {
 669         [TCA_TAPRIO_SCHED_ENTRY_INDEX]     = { .type = NLA_U32 },
 670         [TCA_TAPRIO_SCHED_ENTRY_CMD]       = { .type = NLA_U8 },
 671         [TCA_TAPRIO_SCHED_ENTRY_GATE_MASK] = { .type = NLA_U32 },
 672         [TCA_TAPRIO_SCHED_ENTRY_INTERVAL]  = { .type = NLA_U32 },
 673 };
 674
 675 static const struct nla_policy entry_list_policy[TCA_TAPRIO_SCHED_MAX + 1] = {
 676         [TCA_TAPRIO_SCHED_ENTRY] = { .type = NLA_NESTED },
 677 };
 678
 679 static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = {
 680         [TCA_TAPRIO_ATTR_PRIOMAP]              = {
 681                 .len = sizeof(struct tc_mqprio_qopt)
 682         },
 683         [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST]           = { .type = NLA_NESTED },
 684         [TCA_TAPRIO_ATTR_SCHED_BASE_TIME]            = { .type = NLA_S64 },
 685         [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]         = { .type = NLA_NESTED },
 686         [TCA_TAPRIO_ATTR_SCHED_CLOCKID]              = { .type = NLA_S32 },
 687         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]           = { .type = NLA_S64 },
 688         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
 689 };
 690
 691 static int fill_sched_entry(struct nlattr **tb, struct sched_entry *entry,
 692                             struct netlink_ext_ack *extack)
 693 {
 694         u32 interval = 0;
 695
 696         if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
 697                 entry->command = nla_get_u8(
 698                         tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
 699
 700         if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
 701                 entry->gate_mask = nla_get_u32(
 702                         tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
 703
 704         if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
 705                 interval = nla_get_u32(
 706                         tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
 707
 708         if (interval == 0) {
 709                 NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
 710                 return -EINVAL;
 711         }
 712
 713         entry->interval = interval;
 714
 715         return 0;
 716 }
 717
 718 static int parse_sched_entry(struct nlattr *n, struct sched_entry *entry,
 719                              int index, struct netlink_ext_ack *extack)
 720 {
 721         struct nlattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { };
 722         int err;
 723
 724         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, n,
 725                                           entry_policy, NULL);
 726         if (err < 0) {
 727                 NL_SET_ERR_MSG(extack, "Could not parse nested entry");
 728                 return -EINVAL;
 729         }
 730
 731         entry->index = index;
 732
 733         return fill_sched_entry(tb, entry, extack);
 734 }
 735
 736 static int parse_sched_list(struct nlattr *list,
 737                             struct sched_gate_list *sched,
 738                             struct netlink_ext_ack *extack)
 739 {
 740         struct nlattr *n;
 741         int err, rem;
 742         int i = 0;
 743
 744         if (!list)
 745                 return -EINVAL;
 746
 747         nla_for_each_nested(n, list, rem) {
 748                 struct sched_entry *entry;
 749
 750                 if (nla_type(n) != TCA_TAPRIO_SCHED_ENTRY) {
 751                         NL_SET_ERR_MSG(extack, "Attribute is not of type 'entry'");
 752                         continue;
 753                 }
 754
 755                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 756                 if (!entry) {
 757                         NL_SET_ERR_MSG(extack, "Not enough memory for entry");
 758                         return -ENOMEM;
 759                 }
 760
 761                 err = parse_sched_entry(n, entry, i, extack);
 762                 if (err < 0) {
 763                         kfree(entry);
 764                         return err;
 765                 }
 766
 767                 list_add_tail(&entry->list, &sched->entries);
 768                 i++;
 769         }
 770
 771         sched->num_entries = i;
 772
 773         return i;
 774 }
 775
 776 static int parse_taprio_schedule(struct nlattr **tb,
 777                                  struct sched_gate_list *new,
 778                                  struct netlink_ext_ack *extack)
 779 {
 780         int err = 0;
 781
 782         if (tb[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]) {
 783                 NL_SET_ERR_MSG(extack, "Adding a single entry is not supported");
 784                 return -ENOTSUPP;
 785         }
 786
 787         if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
 788                 new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
 789
 790         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
 791                 new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
 792
 793         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
 794                 new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
 795
 796         if (tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST])
 797                 err = parse_sched_list(
 798                         tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST], new, extack);
 799         if (err < 0)
 800                 return err;
 801
 802         if (!new->cycle_time) {
 803                 struct sched_entry *entry;
 804                 ktime_t cycle = 0;
 805
 806                 list_for_each_entry(entry, &new->entries, list)
 807                         cycle = ktime_add_ns(cycle, entry->interval);
 808                 new->cycle_time = cycle;
 809         }
 810
 811         return 0;
 812 }
 813
 814 static int taprio_parse_mqprio_opt(struct net_device *dev,
 815                                    struct tc_mqprio_qopt *qopt,
 816                                    struct netlink_ext_ack *extack,
 817                                    u32 taprio_flags)
 818 {
 819         int i, j;
 820
 821         if (!qopt && !dev->num_tc) {
 822                 NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
 823                 return -EINVAL;
 824         }
 825
 826         /* If num_tc is already set, it means that the user already
 827          * configured the mqprio part
 828          */
 829         if (dev->num_tc)
 830                 return 0;
 831
 832         /* Verify num_tc is not out of max range */
 833         if (qopt->num_tc > TC_MAX_QUEUE) {
 834                 NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
 835                 return -EINVAL;
 836         }
 837
 838         /* taprio imposes that traffic classes map 1:n to tx queues */
 839         if (qopt->num_tc > dev->num_tx_queues) {
 840                 NL_SET_ERR_MSG(extack, "Number of traffic classes is greater than number of HW queues");
 841                 return -EINVAL;
 842         }
 843
 844         /* Verify priority mapping uses valid tcs */
 845         for (i = 0; i < TC_BITMASK + 1; i++) {
 846                 if (qopt->prio_tc_map[i] >= qopt->num_tc) {
 847                         NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping");
 848                         return -EINVAL;
 849                 }
 850         }
 851
 852         for (i = 0; i < qopt->num_tc; i++) {
 853                 unsigned int last = qopt->offset[i] + qopt->count[i];
 854
 855                 /* Verify the queue count is in tx range being equal to the
 856                  * real_num_tx_queues indicates the last queue is in use.
 857                  */
 858                 if (qopt->offset[i] >= dev->num_tx_queues ||
 859                     !qopt->count[i] ||
 860                     last > dev->real_num_tx_queues) {
 861                         NL_SET_ERR_MSG(extack, "Invalid queue in traffic class to queue mapping");
 862                         return -EINVAL;
 863                 }
 864
 865                 if (TXTIME_ASSIST_IS_ENABLED(taprio_flags))
 866                         continue;
 867
 868                 /* Verify that the offset and counts do not overlap */
 869                 for (j = i + 1; j < qopt->num_tc; j++) {
 870                         if (last > qopt->offset[j]) {
 871                                 NL_SET_ERR_MSG(extack, "Detected overlap in the traffic class to queue mapping");
 872                                 return -EINVAL;
 873                         }
 874                 }
 875         }
 876
 877         return 0;
 878 }
 879
 880 static int taprio_get_start_time(struct Qdisc *sch,
 881                                  struct sched_gate_list *sched,
 882                                  ktime_t *start)
 883 {
 884         struct taprio_sched *q = qdisc_priv(sch);
 885         ktime_t now, base, cycle;
 886         s64 n;
 887
 888         base = sched_base_time(sched);
 889         now = taprio_get_time(q);
 890
 891         if (ktime_after(base, now)) {
 892                 *start = base;
 893                 return 0;
 894         }
 895
 896         cycle = sched->cycle_time;
 897
 898         /* The qdisc is expected to have at least one sched_entry.  Moreover,
 899          * any entry must have 'interval' > 0. Thus if the cycle time is zero,
 900          * something went really wrong. In that case, we should warn about this
 901          * inconsistent state and return error.
 902          */
 903         if (WARN_ON(!cycle))
 904                 return -EFAULT;
 905
 906         /* Schedule the start time for the beginning of the next
 907          * cycle.
 908          */
 909         n = div64_s64(ktime_sub_ns(now, base), cycle);
 910         *start = ktime_add_ns(base, (n + 1) * cycle);
 911         return 0;
 912 }
 913
 914 static void setup_first_close_time(struct taprio_sched *q,
 915                                    struct sched_gate_list *sched, ktime_t base)
 916 {
 917         struct sched_entry *first;
 918         ktime_t cycle;
 919
 920         first = list_first_entry(&sched->entries,
 921                                  struct sched_entry, list);
 922
 923         cycle = sched->cycle_time;
 924
 925         /* FIXME: find a better place to do this */
 926         sched->cycle_close_time = ktime_add_ns(base, cycle);
 927
 928         first->close_time = ktime_add_ns(base, first->interval);
 929         taprio_set_budget(q, first);
 930         rcu_assign_pointer(q->current_entry, NULL);
 931 }
 932
 933 static void taprio_start_sched(struct Qdisc *sch,
 934                                ktime_t start, struct sched_gate_list *new)
 935 {
 936         struct taprio_sched *q = qdisc_priv(sch);
 937         ktime_t expires;
 938
 939         expires = hrtimer_get_expires(&q->advance_timer);
 940         if (expires == 0)
 941                 expires = KTIME_MAX;
 942
 943         /* If the new schedule starts before the next expiration, we
 944          * reprogram it to the earliest one, so we change the admin
 945          * schedule to the operational one at the right time.
 946          */
 947         start = min_t(ktime_t, start, expires);
 948
 949         hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS);
 950 }
 951
 952 static void taprio_set_picos_per_byte(struct net_device *dev,
 953                                       struct taprio_sched *q)
 954 {
 955         struct ethtool_link_ksettings ecmd;
 956         int speed = SPEED_10;
 957         int picos_per_byte;
 958         int err;
 959
 960         err = __ethtool_get_link_ksettings(dev, &ecmd);
 961         if (err < 0)
 962                 goto skip;
 963
 964         if (ecmd.base.speed != SPEED_UNKNOWN)
 965                 speed = ecmd.base.speed;
 966
 967 skip:
 968         picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8,
 969                                    speed * 1000 * 1000);
 970
 971         atomic64_set(&q->picos_per_byte, picos_per_byte);
 972         netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
 973                    dev->name, (long long)atomic64_read(&q->picos_per_byte),
 974                    ecmd.base.speed);
 975 }
 976
 977 static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
 978                                void *ptr)
 979 {
 980         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 981         struct net_device *qdev;
 982         struct taprio_sched *q;
 983         bool found = false;
 984
 985         ASSERT_RTNL();
 986
 987         if (event != NETDEV_UP && event != NETDEV_CHANGE)
 988                 return NOTIFY_DONE;
 989
 990         spin_lock(&taprio_list_lock);
 991         list_for_each_entry(q, &taprio_list, taprio_list) {
 992                 qdev = qdisc_dev(q->root);
 993                 if (qdev == dev) {
 994                         found = true;
 995                         break;
 996                 }
 997         }
 998         spin_unlock(&taprio_list_lock);
 999
1000         if (found)
1001                 taprio_set_picos_per_byte(dev, q);
1002
1003         return NOTIFY_DONE;
1004 }
1005
1006 static void setup_txtime(struct taprio_sched *q,
1007                          struct sched_gate_list *sched, ktime_t base)
1008 {
1009         struct sched_entry *entry;
1010         u32 interval = 0;
1011
1012         list_for_each_entry(entry, &sched->entries, list) {
1013                 entry->next_txtime = ktime_add_ns(base, interval);
1014                 interval += entry->interval;
1015         }
1016 }
1017
1018 static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
1019                          struct netlink_ext_ack *extack)
1020 {
1021         struct nlattr *tb[TCA_TAPRIO_ATTR_MAX + 1] = { };
1022         struct sched_gate_list *oper, *admin, *new_admin;
1023         struct taprio_sched *q = qdisc_priv(sch);
1024         struct net_device *dev = qdisc_dev(sch);
1025         struct tc_mqprio_qopt *mqprio = NULL;
1026         u32 taprio_flags = 0;
1027         int i, err, clockid;
1028         unsigned long flags;
1029         ktime_t start;
1030
1031         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_ATTR_MAX, opt,
1032                                           taprio_policy, extack);
1033         if (err < 0)
1034                 return err;
1035
1036         if (tb[TCA_TAPRIO_ATTR_PRIOMAP])
1037                 mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]);
1038
1039         if (tb[TCA_TAPRIO_ATTR_FLAGS]) {
1040                 taprio_flags = nla_get_u32(tb[TCA_TAPRIO_ATTR_FLAGS]);
1041
1042                 if (q->flags != 0 && q->flags != taprio_flags) {
1043                         NL_SET_ERR_MSG_MOD(extack, "Changing 'flags' of a running schedule is not supported");
1044                         return -EOPNOTSUPP;
1045                 } else if (!FLAGS_VALID(taprio_flags)) {
1046                         NL_SET_ERR_MSG_MOD(extack, "Specified 'flags' are not valid");
1047                         return -EINVAL;
1048                 }
1049
1050                 q->flags = taprio_flags;
1051         }
1052
1053         err = taprio_parse_mqprio_opt(dev, mqprio, extack, taprio_flags);
1054         if (err < 0)
1055                 return err;
1056
1057         new_admin = kzalloc(sizeof(*new_admin), GFP_KERNEL);
1058         if (!new_admin) {
1059                 NL_SET_ERR_MSG(extack, "Not enough memory for a new schedule");
1060                 return -ENOMEM;
1061         }
1062         INIT_LIST_HEAD(&new_admin->entries);
1063
1064         rcu_read_lock();
1065         oper = rcu_dereference(q->oper_sched);
1066         admin = rcu_dereference(q->admin_sched);
1067         rcu_read_unlock();
1068
1069         if (mqprio && (oper || admin)) {
1070                 NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
1071                 err = -ENOTSUPP;
1072                 goto free_sched;
1073         }
1074
1075         err = parse_taprio_schedule(tb, new_admin, extack);
1076         if (err < 0)
1077                 goto free_sched;
1078
1079         if (new_admin->num_entries == 0) {
1080                 NL_SET_ERR_MSG(extack, "There should be at least one entry in the schedule");
1081                 err = -EINVAL;
1082                 goto free_sched;
1083         }
1084
1085         if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1086                 clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
1087
1088                 /* We only support static clockids and we don't allow
1089                  * for it to be modified after the first init.
1090                  */
1091                 if (clockid < 0 ||
1092                     (q->clockid != -1 && q->clockid != clockid)) {
1093                         NL_SET_ERR_MSG(extack, "Changing the 'clockid' of a running schedule is not supported");
1094                         err = -ENOTSUPP;
1095                         goto free_sched;
1096                 }
1097
1098                 q->clockid = clockid;
1099         }
1100
1101         if (q->clockid == -1 && !tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1102                 NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
1103                 err = -EINVAL;
1104                 goto free_sched;
1105         }
1106
1107         taprio_set_picos_per_byte(dev, q);
1108
1109         /* Protects against enqueue()/dequeue() */
1110         spin_lock_bh(qdisc_lock(sch));
1111
1112         if (tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]) {
1113                 if (!TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1114                         NL_SET_ERR_MSG_MOD(extack, "txtime-delay can only be set when txtime-assist mode is enabled");
1115                         err = -EINVAL;
1116                         goto unlock;
1117                 }
1118
1119                 q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
1120         }
1121
1122         if (!TXTIME_ASSIST_IS_ENABLED(taprio_flags) &&
1123             !hrtimer_active(&q->advance_timer)) {
1124                 hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
1125                 q->advance_timer.function = advance_sched;
1126         }
1127
1128         if (mqprio) {
1129                 netdev_set_num_tc(dev, mqprio->num_tc);
1130                 for (i = 0; i < mqprio->num_tc; i++)
1131                         netdev_set_tc_queue(dev, i,
1132                                             mqprio->count[i],
1133                                             mqprio->offset[i]);
1134
1135                 /* Always use supplied priority mappings */
1136                 for (i = 0; i < TC_BITMASK + 1; i++)
1137                         netdev_set_prio_tc_map(dev, i,
1138                                                mqprio->prio_tc_map[i]);
1139         }
1140
1141         switch (q->clockid) {
1142         case CLOCK_REALTIME:
1143                 q->tk_offset = TK_OFFS_REAL;
1144                 break;
1145         case CLOCK_MONOTONIC:
1146                 q->tk_offset = TK_OFFS_MAX;
1147                 break;
1148         case CLOCK_BOOTTIME:
1149                 q->tk_offset = TK_OFFS_BOOT;
1150                 break;
1151         case CLOCK_TAI:
1152                 q->tk_offset = TK_OFFS_TAI;
1153                 break;
1154         default:
1155                 NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
1156                 err = -EINVAL;
1157                 goto unlock;
1158         }
1159
1160         err = taprio_get_start_time(sch, new_admin, &start);
1161         if (err < 0) {
1162                 NL_SET_ERR_MSG(extack, "Internal error: failed get start time");
1163                 goto unlock;
1164         }
1165
1166         if (TXTIME_ASSIST_IS_ENABLED(taprio_flags)) {
1167                 setup_txtime(q, new_admin, start);
1168
1169                 if (!oper) {
1170                         rcu_assign_pointer(q->oper_sched, new_admin);
1171                         err = 0;
1172                         new_admin = NULL;
1173                         goto unlock;
1174                 }
1175
1176                 rcu_assign_pointer(q->admin_sched, new_admin);
1177                 if (admin)
1178                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1179         } else {
1180                 setup_first_close_time(q, new_admin, start);
1181
1182                 /* Protects against advance_sched() */
1183                 spin_lock_irqsave(&q->current_entry_lock, flags);
1184
1185                 taprio_start_sched(sch, start, new_admin);
1186
1187                 rcu_assign_pointer(q->admin_sched, new_admin);
1188                 if (admin)
1189                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1190
1191                 spin_unlock_irqrestore(&q->current_entry_lock, flags);
1192         }
1193
1194         new_admin = NULL;
1195         err = 0;
1196
1197 unlock:
1198         spin_unlock_bh(qdisc_lock(sch));
1199
1200 free_sched:
1201         if (new_admin)
1202                 call_rcu(&new_admin->rcu, taprio_free_sched_cb);
1203
1204         return err;
1205 }
1206
1207 static void taprio_destroy(struct Qdisc *sch)
1208 {
1209         struct taprio_sched *q = qdisc_priv(sch);
1210         struct net_device *dev = qdisc_dev(sch);
1211         unsigned int i;
1212
1213         spin_lock(&taprio_list_lock);
1214         list_del(&q->taprio_list);
1215         spin_unlock(&taprio_list_lock);
1216
1217         hrtimer_cancel(&q->advance_timer);
1218
1219         if (q->qdiscs) {
1220                 for (i = 0; i < dev->num_tx_queues && q->qdiscs[i]; i++)
1221                         qdisc_put(q->qdiscs[i]);
1222
1223                 kfree(q->qdiscs);
1224         }
1225         q->qdiscs = NULL;
1226
1227         netdev_set_num_tc(dev, 0);
1228
1229         if (q->oper_sched)
1230                 call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);
1231
1232         if (q->admin_sched)
1233                 call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb);
1234 }
1235
1236 static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
1237                        struct netlink_ext_ack *extack)
1238 {
1239         struct taprio_sched *q = qdisc_priv(sch);
1240         struct net_device *dev = qdisc_dev(sch);
1241         int i;
1242
1243         spin_lock_init(&q->current_entry_lock);
1244
1245         hrtimer_init(&q->advance_timer, CLOCK_TAI, HRTIMER_MODE_ABS);
1246         q->advance_timer.function = advance_sched;
1247
1248         q->root = sch;
1249
1250         /* We only support static clockids. Use an invalid value as default
1251          * and get the valid one on taprio_change().
1252          */
1253         q->clockid = -1;
1254
1255         spin_lock(&taprio_list_lock);
1256         list_add(&q->taprio_list, &taprio_list);
1257         spin_unlock(&taprio_list_lock);
1258
1259         if (sch->parent != TC_H_ROOT)
1260                 return -EOPNOTSUPP;
1261
1262         if (!netif_is_multiqueue(dev))
1263                 return -EOPNOTSUPP;
1264
1265         /* pre-allocate qdisc, attachment can't fail */
1266         q->qdiscs = kcalloc(dev->num_tx_queues,
1267                             sizeof(q->qdiscs[0]),
1268                             GFP_KERNEL);
1269
1270         if (!q->qdiscs)
1271                 return -ENOMEM;
1272
1273         if (!opt)
1274                 return -EINVAL;
1275
1276         for (i = 0; i < dev->num_tx_queues; i++) {
1277                 struct netdev_queue *dev_queue;
1278                 struct Qdisc *qdisc;
1279
1280                 dev_queue = netdev_get_tx_queue(dev, i);
1281                 qdisc = qdisc_create_dflt(dev_queue,
1282                                           &pfifo_qdisc_ops,
1283                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
1284                                                     TC_H_MIN(i + 1)),
1285                                           extack);
1286                 if (!qdisc)
1287                         return -ENOMEM;
1288
1289                 if (i < dev->real_num_tx_queues)
1290                         qdisc_hash_add(qdisc, false);
1291
1292                 q->qdiscs[i] = qdisc;
1293         }
1294
1295         return taprio_change(sch, opt, extack);
1296 }
1297
1298 static struct netdev_queue *taprio_queue_get(struct Qdisc *sch,
1299                                              unsigned long cl)
1300 {
1301         struct net_device *dev = qdisc_dev(sch);
1302         unsigned long ntx = cl - 1;
1303
1304         if (ntx >= dev->num_tx_queues)
1305                 return NULL;
1306
1307         return netdev_get_tx_queue(dev, ntx);
1308 }
1309
1310 static int taprio_graft(struct Qdisc *sch, unsigned long cl,
1311                         struct Qdisc *new, struct Qdisc **old,
1312                         struct netlink_ext_ack *extack)
1313 {
1314         struct taprio_sched *q = qdisc_priv(sch);
1315         struct net_device *dev = qdisc_dev(sch);
1316         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1317
1318         if (!dev_queue)
1319                 return -EINVAL;
1320
1321         if (dev->flags & IFF_UP)
1322                 dev_deactivate(dev);
1323
1324         *old = q->qdiscs[cl - 1];
1325         q->qdiscs[cl - 1] = new;
1326
1327         if (new)
1328                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1329
1330         if (dev->flags & IFF_UP)
1331                 dev_activate(dev);
1332
1333         return 0;
1334 }
1335
1336 static int dump_entry(struct sk_buff *msg,
1337                       const struct sched_entry *entry)
1338 {
1339         struct nlattr *item;
1340
1341         item = nla_nest_start_noflag(msg, TCA_TAPRIO_SCHED_ENTRY);
1342         if (!item)
1343                 return -ENOSPC;
1344
1345         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INDEX, entry->index))
1346                 goto nla_put_failure;
1347
1348         if (nla_put_u8(msg, TCA_TAPRIO_SCHED_ENTRY_CMD, entry->command))
1349                 goto nla_put_failure;
1350
1351         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_GATE_MASK,
1352                         entry->gate_mask))
1353                 goto nla_put_failure;
1354
1355         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INTERVAL,
1356                         entry->interval))
1357                 goto nla_put_failure;
1358
1359         return nla_nest_end(msg, item);
1360
1361 nla_put_failure:
1362         nla_nest_cancel(msg, item);
1363         return -1;
1364 }
1365
1366 static int dump_schedule(struct sk_buff *msg,
1367                          const struct sched_gate_list *root)
1368 {
1369         struct nlattr *entry_list;
1370         struct sched_entry *entry;
1371
1372         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_BASE_TIME,
1373                         root->base_time, TCA_TAPRIO_PAD))
1374                 return -1;
1375
1376         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME,
1377                         root->cycle_time, TCA_TAPRIO_PAD))
1378                 return -1;
1379
1380         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION,
1381                         root->cycle_time_extension, TCA_TAPRIO_PAD))
1382                 return -1;
1383
1384         entry_list = nla_nest_start_noflag(msg,
1385                                            TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST);
1386         if (!entry_list)
1387                 goto error_nest;
1388
1389         list_for_each_entry(entry, &root->entries, list) {
1390                 if (dump_entry(msg, entry) < 0)
1391                         goto error_nest;
1392         }
1393
1394         nla_nest_end(msg, entry_list);
1395         return 0;
1396
1397 error_nest:
1398         nla_nest_cancel(msg, entry_list);
1399         return -1;
1400 }
1401
1402 static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
1403 {
1404         struct taprio_sched *q = qdisc_priv(sch);
1405         struct net_device *dev = qdisc_dev(sch);
1406         struct sched_gate_list *oper, *admin;
1407         struct tc_mqprio_qopt opt = { 0 };
1408         struct nlattr *nest, *sched_nest;
1409         unsigned int i;
1410
1411         rcu_read_lock();
1412         oper = rcu_dereference(q->oper_sched);
1413         admin = rcu_dereference(q->admin_sched);
1414
1415         opt.num_tc = netdev_get_num_tc(dev);
1416         memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
1417
1418         for (i = 0; i < netdev_get_num_tc(dev); i++) {
1419                 opt.count[i] = dev->tc_to_txq[i].count;
1420                 opt.offset[i] = dev->tc_to_txq[i].offset;
1421         }
1422
1423         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1424         if (!nest)
1425                 goto start_error;
1426
1427         if (nla_put(skb, TCA_TAPRIO_ATTR_PRIOMAP, sizeof(opt), &opt))
1428                 goto options_error;
1429
1430         if (nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
1431                 goto options_error;
1432
1433         if (q->flags && nla_put_u32(skb, TCA_TAPRIO_ATTR_FLAGS, q->flags))
1434                 goto options_error;
1435
1436         if (q->txtime_delay &&
1437             nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
1438                 goto options_error;
1439
1440         if (oper && dump_schedule(skb, oper))
1441                 goto options_error;
1442
1443         if (!admin)
1444                 goto done;
1445
1446         sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
1447         if (!sched_nest)
1448                 goto options_error;
1449
1450         if (dump_schedule(skb, admin))
1451                 goto admin_error;
1452
1453         nla_nest_end(skb, sched_nest);
1454
1455 done:
1456         rcu_read_unlock();
1457
1458         return nla_nest_end(skb, nest);
1459
1460 admin_error:
1461         nla_nest_cancel(skb, sched_nest);
1462
1463 options_error:
1464         nla_nest_cancel(skb, nest);
1465
1466 start_error:
1467         rcu_read_unlock();
1468         return -ENOSPC;
1469 }
1470
1471 static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
1472 {
1473         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1474
1475         if (!dev_queue)
1476                 return NULL;
1477
1478         return dev_queue->qdisc_sleeping;
1479 }
1480
1481 static unsigned long taprio_find(struct Qdisc *sch, u32 classid)
1482 {
1483         unsigned int ntx = TC_H_MIN(classid);
1484
1485         if (!taprio_queue_get(sch, ntx))
1486                 return 0;
1487         return ntx;
1488 }
1489
1490 static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
1491                              struct sk_buff *skb, struct tcmsg *tcm)
1492 {
1493         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1494
1495         tcm->tcm_parent = TC_H_ROOT;
1496         tcm->tcm_handle |= TC_H_MIN(cl);
1497         tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
1498
1499         return 0;
1500 }
1501
1502 static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
1503                                    struct gnet_dump *d)
1504         __releases(d->lock)
1505         __acquires(d->lock)
1506 {
1507         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1508
1509         sch = dev_queue->qdisc_sleeping;
1510         if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
1511             qdisc_qstats_copy(d, sch) < 0)
1512                 return -1;
1513         return 0;
1514 }
1515
1516 static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1517 {
1518         struct net_device *dev = qdisc_dev(sch);
1519         unsigned long ntx;
1520
1521         if (arg->stop)
1522                 return;
1523
1524         arg->count = arg->skip;
1525         for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
1526                 if (arg->fn(sch, ntx + 1, arg) < 0) {
1527                         arg->stop = 1;
1528                         break;
1529                 }
1530                 arg->count++;
1531         }
1532 }
1533
1534 static struct netdev_queue *taprio_select_queue(struct Qdisc *sch,
1535                                                 struct tcmsg *tcm)
1536 {
1537         return taprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
1538 }
1539
1540 static const struct Qdisc_class_ops taprio_class_ops = {
1541         .graft          = taprio_graft,
1542         .leaf           = taprio_leaf,
1543         .find           = taprio_find,
1544         .walk           = taprio_walk,
1545         .dump           = taprio_dump_class,
1546         .dump_stats     = taprio_dump_class_stats,
1547         .select_queue   = taprio_select_queue,
1548 };
1549
1550 static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
1551         .cl_ops         = &taprio_class_ops,
1552         .id             = "taprio",
1553         .priv_size      = sizeof(struct taprio_sched),
1554         .init           = taprio_init,
1555         .change         = taprio_change,
1556         .destroy        = taprio_destroy,
1557         .peek           = taprio_peek,
1558         .dequeue        = taprio_dequeue,
1559         .enqueue        = taprio_enqueue,
1560         .dump           = taprio_dump,
1561         .owner          = THIS_MODULE,
1562 };
1563
1564 static struct notifier_block taprio_device_notifier = {
1565         .notifier_call = taprio_dev_notifier,
1566 };
1567
1568 static int __init taprio_module_init(void)
1569 {
1570         int err = register_netdevice_notifier(&taprio_device_notifier);
1571
1572         if (err)
1573                 return err;
1574
1575         return register_qdisc(&taprio_qdisc_ops);
1576 }
1577
1578 static void __exit taprio_module_exit(void)
1579 {
1580         unregister_qdisc(&taprio_qdisc_ops);
1581         unregister_netdevice_notifier(&taprio_device_notifier);
1582 }
1583
1584 module_init(taprio_module_init);
1585 module_exit(taprio_module_exit);
1586 MODULE_LICENSE("GPL");