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/ethtool.h>
  10 #include <linux/types.h>
  11 #include <linux/slab.h>
  12 #include <linux/kernel.h>
  13 #include <linux/string.h>
  14 #include <linux/list.h>
  15 #include <linux/errno.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/math64.h>
  18 #include <linux/module.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/rcupdate.h>
  21 #include <net/netlink.h>
  22 #include <net/pkt_sched.h>
  23 #include <net/pkt_cls.h>
  24 #include <net/sch_generic.h>
  25 #include <net/sock.h>
  26 #include <net/tcp.h>
  27
  28 static LIST_HEAD(taprio_list);
  29 static DEFINE_SPINLOCK(taprio_list_lock);
  30
  31 #define TAPRIO_ALL_GATES_OPEN -1
  32
  33 #define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST)
  34 #define FULL_OFFLOAD_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
  35 #define TAPRIO_FLAGS_INVALID U32_MAX
  36
  37 struct sched_entry {
  38         struct list_head list;
  39
  40         /* The instant that this entry "closes" and the next one
  41          * should open, the qdisc will make some effort so that no
  42          * packet leaves after this time.
  43          */
  44         ktime_t close_time;
  45         ktime_t next_txtime;
  46         atomic_t budget;
  47         int index;
  48         u32 gate_mask;
  49         u32 interval;
  50         u8 command;
  51 };
  52
  53 struct sched_gate_list {
  54         struct rcu_head rcu;
  55         struct list_head entries;
  56         size_t num_entries;
  57         ktime_t cycle_close_time;
  58         s64 cycle_time;
  59         s64 cycle_time_extension;
  60         s64 base_time;
  61 };
  62
  63 struct taprio_sched {
  64         struct Qdisc **qdiscs;
  65         struct Qdisc *root;
  66         u32 flags;
  67         enum tk_offsets tk_offset;
  68         int clockid;
  69         atomic64_t picos_per_byte; /* Using picoseconds because for 10Gbps+
  70                                     * speeds it's sub-nanoseconds per byte
  71                                     */
  72
  73         /* Protects the update side of the RCU protected current_entry */
  74         spinlock_t current_entry_lock;
  75         struct sched_entry __rcu *current_entry;
  76         struct sched_gate_list __rcu *oper_sched;
  77         struct sched_gate_list __rcu *admin_sched;
  78         struct hrtimer advance_timer;
  79         struct list_head taprio_list;
  80         struct sk_buff *(*dequeue)(struct Qdisc *sch);
  81         struct sk_buff *(*peek)(struct Qdisc *sch);
  82         u32 txtime_delay;
  83 };
  84
  85 struct __tc_taprio_qopt_offload {
  86         refcount_t users;
  87         struct tc_taprio_qopt_offload offload;
  88 };
  89
  90 static ktime_t sched_base_time(const struct sched_gate_list *sched)
  91 {
  92         if (!sched)
  93                 return KTIME_MAX;
  94
  95         return ns_to_ktime(sched->base_time);
  96 }
  97
  98 static ktime_t taprio_get_time(struct taprio_sched *q)
  99 {
 100         ktime_t mono = ktime_get();
 101
 102         switch (q->tk_offset) {
 103         case TK_OFFS_MAX:
 104                 return mono;
 105         default:
 106                 return ktime_mono_to_any(mono, q->tk_offset);
 107         }
 108
 109         return KTIME_MAX;
 110 }
 111
 112 static void taprio_free_sched_cb(struct rcu_head *head)
 113 {
 114         struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
 115         struct sched_entry *entry, *n;
 116
 117         list_for_each_entry_safe(entry, n, &sched->entries, list) {
 118                 list_del(&entry->list);
 119                 kfree(entry);
 120         }
 121
 122         kfree(sched);
 123 }
 124
 125 static void switch_schedules(struct taprio_sched *q,
 126                              struct sched_gate_list **admin,
 127                              struct sched_gate_list **oper)
 128 {
 129         rcu_assign_pointer(q->oper_sched, *admin);
 130         rcu_assign_pointer(q->admin_sched, NULL);
 131
 132         if (*oper)
 133                 call_rcu(&(*oper)->rcu, taprio_free_sched_cb);
 134
 135         *oper = *admin;
 136         *admin = NULL;
 137 }
 138
 139 /* Get how much time has been already elapsed in the current cycle. */
 140 static s32 get_cycle_time_elapsed(struct sched_gate_list *sched, ktime_t time)
 141 {
 142         ktime_t time_since_sched_start;
 143         s32 time_elapsed;
 144
 145         time_since_sched_start = ktime_sub(time, sched->base_time);
 146         div_s64_rem(time_since_sched_start, sched->cycle_time, &time_elapsed);
 147
 148         return time_elapsed;
 149 }
 150
 151 static ktime_t get_interval_end_time(struct sched_gate_list *sched,
 152                                      struct sched_gate_list *admin,
 153                                      struct sched_entry *entry,
 154                                      ktime_t intv_start)
 155 {
 156         s32 cycle_elapsed = get_cycle_time_elapsed(sched, intv_start);
 157         ktime_t intv_end, cycle_ext_end, cycle_end;
 158
 159         cycle_end = ktime_add_ns(intv_start, sched->cycle_time - cycle_elapsed);
 160         intv_end = ktime_add_ns(intv_start, entry->interval);
 161         cycle_ext_end = ktime_add(cycle_end, sched->cycle_time_extension);
 162
 163         if (ktime_before(intv_end, cycle_end))
 164                 return intv_end;
 165         else if (admin && admin != sched &&
 166                  ktime_after(admin->base_time, cycle_end) &&
 167                  ktime_before(admin->base_time, cycle_ext_end))
 168                 return admin->base_time;
 169         else
 170                 return cycle_end;
 171 }
 172
 173 static int length_to_duration(struct taprio_sched *q, int len)
 174 {
 175         return div_u64(len * atomic64_read(&q->picos_per_byte), 1000);
 176 }
 177
 178 /* Returns the entry corresponding to next available interval. If
 179  * validate_interval is set, it only validates whether the timestamp occurs
 180  * when the gate corresponding to the skb's traffic class is open.
 181  */
 182 static struct sched_entry *find_entry_to_transmit(struct sk_buff *skb,
 183                                                   struct Qdisc *sch,
 184                                                   struct sched_gate_list *sched,
 185                                                   struct sched_gate_list *admin,
 186                                                   ktime_t time,
 187                                                   ktime_t *interval_start,
 188                                                   ktime_t *interval_end,
 189                                                   bool validate_interval)
 190 {
 191         ktime_t curr_intv_start, curr_intv_end, cycle_end, packet_transmit_time;
 192         ktime_t earliest_txtime = KTIME_MAX, txtime, cycle, transmit_end_time;
 193         struct sched_entry *entry = NULL, *entry_found = NULL;
 194         struct taprio_sched *q = qdisc_priv(sch);
 195         struct net_device *dev = qdisc_dev(sch);
 196         bool entry_available = false;
 197         s32 cycle_elapsed;
 198         int tc, n;
 199
 200         tc = netdev_get_prio_tc_map(dev, skb->priority);
 201         packet_transmit_time = length_to_duration(q, qdisc_pkt_len(skb));
 202
 203         *interval_start = 0;
 204         *interval_end = 0;
 205
 206         if (!sched)
 207                 return NULL;
 208
 209         cycle = sched->cycle_time;
 210         cycle_elapsed = get_cycle_time_elapsed(sched, time);
 211         curr_intv_end = ktime_sub_ns(time, cycle_elapsed);
 212         cycle_end = ktime_add_ns(curr_intv_end, cycle);
 213
 214         list_for_each_entry(entry, &sched->entries, list) {
 215                 curr_intv_start = curr_intv_end;
 216                 curr_intv_end = get_interval_end_time(sched, admin, entry,
 217                                                       curr_intv_start);
 218
 219                 if (ktime_after(curr_intv_start, cycle_end))
 220                         break;
 221
 222                 if (!(entry->gate_mask & BIT(tc)) ||
 223                     packet_transmit_time > entry->interval)
 224                         continue;
 225
 226                 txtime = entry->next_txtime;
 227
 228                 if (ktime_before(txtime, time) || validate_interval) {
 229                         transmit_end_time = ktime_add_ns(time, packet_transmit_time);
 230                         if ((ktime_before(curr_intv_start, time) &&
 231                              ktime_before(transmit_end_time, curr_intv_end)) ||
 232                             (ktime_after(curr_intv_start, time) && !validate_interval)) {
 233                                 entry_found = entry;
 234                                 *interval_start = curr_intv_start;
 235                                 *interval_end = curr_intv_end;
 236                                 break;
 237                         } else if (!entry_available && !validate_interval) {
 238                                 /* Here, we are just trying to find out the
 239                                  * first available interval in the next cycle.
 240                                  */
 241                                 entry_available = true;
 242                                 entry_found = entry;
 243                                 *interval_start = ktime_add_ns(curr_intv_start, cycle);
 244                                 *interval_end = ktime_add_ns(curr_intv_end, cycle);
 245                         }
 246                 } else if (ktime_before(txtime, earliest_txtime) &&
 247                            !entry_available) {
 248                         earliest_txtime = txtime;
 249                         entry_found = entry;
 250                         n = div_s64(ktime_sub(txtime, curr_intv_start), cycle);
 251                         *interval_start = ktime_add(curr_intv_start, n * cycle);
 252                         *interval_end = ktime_add(curr_intv_end, n * cycle);
 253                 }
 254         }
 255
 256         return entry_found;
 257 }
 258
 259 static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
 260 {
 261         struct taprio_sched *q = qdisc_priv(sch);
 262         struct sched_gate_list *sched, *admin;
 263         ktime_t interval_start, interval_end;
 264         struct sched_entry *entry;
 265
 266         rcu_read_lock();
 267         sched = rcu_dereference(q->oper_sched);
 268         admin = rcu_dereference(q->admin_sched);
 269
 270         entry = find_entry_to_transmit(skb, sch, sched, admin, skb->tstamp,
 271                                        &interval_start, &interval_end, true);
 272         rcu_read_unlock();
 273
 274         return entry;
 275 }
 276
 277 static bool taprio_flags_valid(u32 flags)
 278 {
 279         /* Make sure no other flag bits are set. */
 280         if (flags & ~(TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST |
 281                       TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD))
 282                 return false;
 283         /* txtime-assist and full offload are mutually exclusive */
 284         if ((flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) &&
 285             (flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD))
 286                 return false;
 287         return true;
 288 }
 289
 290 /* This returns the tstamp value set by TCP in terms of the set clock. */
 291 static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
 292 {
 293         unsigned int offset = skb_network_offset(skb);
 294         const struct ipv6hdr *ipv6h;
 295         const struct iphdr *iph;
 296         struct ipv6hdr _ipv6h;
 297
 298         ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
 299         if (!ipv6h)
 300                 return 0;
 301
 302         if (ipv6h->version == 4) {
 303                 iph = (struct iphdr *)ipv6h;
 304                 offset += iph->ihl * 4;
 305
 306                 /* special-case 6in4 tunnelling, as that is a common way to get
 307                  * v6 connectivity in the home
 308                  */
 309                 if (iph->protocol == IPPROTO_IPV6) {
 310                         ipv6h = skb_header_pointer(skb, offset,
 311                                                    sizeof(_ipv6h), &_ipv6h);
 312
 313                         if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
 314                                 return 0;
 315                 } else if (iph->protocol != IPPROTO_TCP) {
 316                         return 0;
 317                 }
 318         } else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
 319                 return 0;
 320         }
 321
 322         return ktime_mono_to_any(skb->skb_mstamp_ns, q->tk_offset);
 323 }
 324
 325 /* There are a few scenarios where we will have to modify the txtime from
 326  * what is read from next_txtime in sched_entry. They are:
 327  * 1. If txtime is in the past,
 328  *    a. The gate for the traffic class is currently open and packet can be
 329  *       transmitted before it closes, schedule the packet right away.
 330  *    b. If the gate corresponding to the traffic class is going to open later
 331  *       in the cycle, set the txtime of packet to the interval start.
 332  * 2. If txtime is in the future, there are packets corresponding to the
 333  *    current traffic class waiting to be transmitted. So, the following
 334  *    possibilities exist:
 335  *    a. We can transmit the packet before the window containing the txtime
 336  *       closes.
 337  *    b. The window might close before the transmission can be completed
 338  *       successfully. So, schedule the packet in the next open window.
 339  */
 340 static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 341 {
 342         ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
 343         struct taprio_sched *q = qdisc_priv(sch);
 344         struct sched_gate_list *sched, *admin;
 345         ktime_t minimum_time, now, txtime;
 346         int len, packet_transmit_time;
 347         struct sched_entry *entry;
 348         bool sched_changed;
 349
 350         now = taprio_get_time(q);
 351         minimum_time = ktime_add_ns(now, q->txtime_delay);
 352
 353         tcp_tstamp = get_tcp_tstamp(q, skb);
 354         minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
 355
 356         rcu_read_lock();
 357         admin = rcu_dereference(q->admin_sched);
 358         sched = rcu_dereference(q->oper_sched);
 359         if (admin && ktime_after(minimum_time, admin->base_time))
 360                 switch_schedules(q, &admin, &sched);
 361
 362         /* Until the schedule starts, all the queues are open */
 363         if (!sched || ktime_before(minimum_time, sched->base_time)) {
 364                 txtime = minimum_time;
 365                 goto done;
 366         }
 367
 368         len = qdisc_pkt_len(skb);
 369         packet_transmit_time = length_to_duration(q, len);
 370
 371         do {
 372                 sched_changed = false;
 373
 374                 entry = find_entry_to_transmit(skb, sch, sched, admin,
 375                                                minimum_time,
 376                                                &interval_start, &interval_end,
 377                                                false);
 378                 if (!entry) {
 379                         txtime = 0;
 380                         goto done;
 381                 }
 382
 383                 txtime = entry->next_txtime;
 384                 txtime = max_t(ktime_t, txtime, minimum_time);
 385                 txtime = max_t(ktime_t, txtime, interval_start);
 386
 387                 if (admin && admin != sched &&
 388                     ktime_after(txtime, admin->base_time)) {
 389                         sched = admin;
 390                         sched_changed = true;
 391                         continue;
 392                 }
 393
 394                 transmit_end_time = ktime_add(txtime, packet_transmit_time);
 395                 minimum_time = transmit_end_time;
 396
 397                 /* Update the txtime of current entry to the next time it's
 398                  * interval starts.
 399                  */
 400                 if (ktime_after(transmit_end_time, interval_end))
 401                         entry->next_txtime = ktime_add(interval_start, sched->cycle_time);
 402         } while (sched_changed || ktime_after(transmit_end_time, interval_end));
 403
 404         entry->next_txtime = transmit_end_time;
 405
 406 done:
 407         rcu_read_unlock();
 408         return txtime;
 409 }
 410
 411 static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch,
 412                               struct Qdisc *child, struct sk_buff **to_free)
 413 {
 414         struct taprio_sched *q = qdisc_priv(sch);
 415
 416         if (skb->sk && sock_flag(skb->sk, SOCK_TXTIME)) {
 417                 if (!is_valid_interval(skb, sch))
 418                         return qdisc_drop(skb, sch, to_free);
 419         } else if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 420                 skb->tstamp = get_packet_txtime(skb, sch);
 421                 if (!skb->tstamp)
 422                         return qdisc_drop(skb, sch, to_free);
 423         }
 424
 425         qdisc_qstats_backlog_inc(sch, skb);
 426         sch->q.qlen++;
 427
 428         return qdisc_enqueue(skb, child, to_free);
 429 }
 430
 431 static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 432                           struct sk_buff **to_free)
 433 {
 434         struct taprio_sched *q = qdisc_priv(sch);
 435         struct Qdisc *child;
 436         int queue;
 437
 438         if (unlikely(FULL_OFFLOAD_IS_ENABLED(q->flags))) {
 439                 WARN_ONCE(1, "Trying to enqueue skb into the root of a taprio qdisc configured with full offload\n");
 440                 return qdisc_drop(skb, sch, to_free);
 441         }
 442
 443         queue = skb_get_queue_mapping(skb);
 444
 445         child = q->qdiscs[queue];
 446         if (unlikely(!child))
 447                 return qdisc_drop(skb, sch, to_free);
 448
 449         /* Large packets might not be transmitted when the transmission duration
 450          * exceeds any configured interval. Therefore, segment the skb into
 451          * smaller chunks. Skip it for the full offload case, as the driver
 452          * and/or the hardware is expected to handle this.
 453          */
 454         if (skb_is_gso(skb) && !FULL_OFFLOAD_IS_ENABLED(q->flags)) {
 455                 unsigned int slen = 0, numsegs = 0, len = qdisc_pkt_len(skb);
 456                 netdev_features_t features = netif_skb_features(skb);
 457                 struct sk_buff *segs, *nskb;
 458                 int ret;
 459
 460                 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
 461                 if (IS_ERR_OR_NULL(segs))
 462                         return qdisc_drop(skb, sch, to_free);
 463
 464                 skb_list_walk_safe(segs, segs, nskb) {
 465                         skb_mark_not_on_list(segs);
 466                         qdisc_skb_cb(segs)->pkt_len = segs->len;
 467                         slen += segs->len;
 468
 469                         ret = taprio_enqueue_one(segs, sch, child, to_free);
 470                         if (ret != NET_XMIT_SUCCESS) {
 471                                 if (net_xmit_drop_count(ret))
 472                                         qdisc_qstats_drop(sch);
 473                         } else {
 474                                 numsegs++;
 475                         }
 476                 }
 477
 478                 if (numsegs > 1)
 479                         qdisc_tree_reduce_backlog(sch, 1 - numsegs, len - slen);
 480                 consume_skb(skb);
 481
 482                 return numsegs > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 483         }
 484
 485         return taprio_enqueue_one(skb, sch, child, to_free);
 486 }
 487
 488 static struct sk_buff *taprio_peek_soft(struct Qdisc *sch)
 489 {
 490         struct taprio_sched *q = qdisc_priv(sch);
 491         struct net_device *dev = qdisc_dev(sch);
 492         struct sched_entry *entry;
 493         struct sk_buff *skb;
 494         u32 gate_mask;
 495         int i;
 496
 497         rcu_read_lock();
 498         entry = rcu_dereference(q->current_entry);
 499         gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 500         rcu_read_unlock();
 501
 502         if (!gate_mask)
 503                 return NULL;
 504
 505         for (i = 0; i < dev->num_tx_queues; i++) {
 506                 struct Qdisc *child = q->qdiscs[i];
 507                 int prio;
 508                 u8 tc;
 509
 510                 if (unlikely(!child))
 511                         continue;
 512
 513                 skb = child->ops->peek(child);
 514                 if (!skb)
 515                         continue;
 516
 517                 if (TXTIME_ASSIST_IS_ENABLED(q->flags))
 518                         return skb;
 519
 520                 prio = skb->priority;
 521                 tc = netdev_get_prio_tc_map(dev, prio);
 522
 523                 if (!(gate_mask & BIT(tc)))
 524                         continue;
 525
 526                 return skb;
 527         }
 528
 529         return NULL;
 530 }
 531
 532 static struct sk_buff *taprio_peek_offload(struct Qdisc *sch)
 533 {
 534         WARN_ONCE(1, "Trying to peek into the root of a taprio qdisc configured with full offload\n");
 535
 536         return NULL;
 537 }
 538
 539 static struct sk_buff *taprio_peek(struct Qdisc *sch)
 540 {
 541         struct taprio_sched *q = qdisc_priv(sch);
 542
 543         return q->peek(sch);
 544 }
 545
 546 static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry)
 547 {
 548         atomic_set(&entry->budget,
 549                    div64_u64((u64)entry->interval * 1000,
 550                              atomic64_read(&q->picos_per_byte)));
 551 }
 552
 553 static struct sk_buff *taprio_dequeue_soft(struct Qdisc *sch)
 554 {
 555         struct taprio_sched *q = qdisc_priv(sch);
 556         struct net_device *dev = qdisc_dev(sch);
 557         struct sk_buff *skb = NULL;
 558         struct sched_entry *entry;
 559         u32 gate_mask;
 560         int i;
 561
 562         rcu_read_lock();
 563         entry = rcu_dereference(q->current_entry);
 564         /* if there's no entry, it means that the schedule didn't
 565          * start yet, so force all gates to be open, this is in
 566          * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5
 567          * "AdminGateStates"
 568          */
 569         gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 570
 571         if (!gate_mask)
 572                 goto done;
 573
 574         for (i = 0; i < dev->num_tx_queues; i++) {
 575                 struct Qdisc *child = q->qdiscs[i];
 576                 ktime_t guard;
 577                 int prio;
 578                 int len;
 579                 u8 tc;
 580
 581                 if (unlikely(!child))
 582                         continue;
 583
 584                 if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 585                         skb = child->ops->dequeue(child);
 586                         if (!skb)
 587                                 continue;
 588                         goto skb_found;
 589                 }
 590
 591                 skb = child->ops->peek(child);
 592                 if (!skb)
 593                         continue;
 594
 595                 prio = skb->priority;
 596                 tc = netdev_get_prio_tc_map(dev, prio);
 597
 598                 if (!(gate_mask & BIT(tc))) {
 599                         skb = NULL;
 600                         continue;
 601                 }
 602
 603                 len = qdisc_pkt_len(skb);
 604                 guard = ktime_add_ns(taprio_get_time(q),
 605                                      length_to_duration(q, len));
 606
 607                 /* In the case that there's no gate entry, there's no
 608                  * guard band ...
 609                  */
 610                 if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 611                     ktime_after(guard, entry->close_time)) {
 612                         skb = NULL;
 613                         continue;
 614                 }
 615
 616                 /* ... and no budget. */
 617                 if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 618                     atomic_sub_return(len, &entry->budget) < 0) {
 619                         skb = NULL;
 620                         continue;
 621                 }
 622
 623                 skb = child->ops->dequeue(child);
 624                 if (unlikely(!skb))
 625                         goto done;
 626
 627 skb_found:
 628                 qdisc_bstats_update(sch, skb);
 629                 qdisc_qstats_backlog_dec(sch, skb);
 630                 sch->q.qlen--;
 631
 632                 goto done;
 633         }
 634
 635 done:
 636         rcu_read_unlock();
 637
 638         return skb;
 639 }
 640
 641 static struct sk_buff *taprio_dequeue_offload(struct Qdisc *sch)
 642 {
 643         WARN_ONCE(1, "Trying to dequeue from the root of a taprio qdisc configured with full offload\n");
 644
 645         return NULL;
 646 }
 647
 648 static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 649 {
 650         struct taprio_sched *q = qdisc_priv(sch);
 651
 652         return q->dequeue(sch);
 653 }
 654
 655 static bool should_restart_cycle(const struct sched_gate_list *oper,
 656                                  const struct sched_entry *entry)
 657 {
 658         if (list_is_last(&entry->list, &oper->entries))
 659                 return true;
 660
 661         if (ktime_compare(entry->close_time, oper->cycle_close_time) == 0)
 662                 return true;
 663
 664         return false;
 665 }
 666
 667 static bool should_change_schedules(const struct sched_gate_list *admin,
 668                                     const struct sched_gate_list *oper,
 669                                     ktime_t close_time)
 670 {
 671         ktime_t next_base_time, extension_time;
 672
 673         if (!admin)
 674                 return false;
 675
 676         next_base_time = sched_base_time(admin);
 677
 678         /* This is the simple case, the close_time would fall after
 679          * the next schedule base_time.
 680          */
 681         if (ktime_compare(next_base_time, close_time) <= 0)
 682                 return true;
 683
 684         /* This is the cycle_time_extension case, if the close_time
 685          * plus the amount that can be extended would fall after the
 686          * next schedule base_time, we can extend the current schedule
 687          * for that amount.
 688          */
 689         extension_time = ktime_add_ns(close_time, oper->cycle_time_extension);
 690
 691         /* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about
 692          * how precisely the extension should be made. So after
 693          * conformance testing, this logic may change.
 694          */
 695         if (ktime_compare(next_base_time, extension_time) <= 0)
 696                 return true;
 697
 698         return false;
 699 }
 700
 701 static enum hrtimer_restart advance_sched(struct hrtimer *timer)
 702 {
 703         struct taprio_sched *q = container_of(timer, struct taprio_sched,
 704                                               advance_timer);
 705         struct sched_gate_list *oper, *admin;
 706         struct sched_entry *entry, *next;
 707         struct Qdisc *sch = q->root;
 708         ktime_t close_time;
 709
 710         spin_lock(&q->current_entry_lock);
 711         entry = rcu_dereference_protected(q->current_entry,
 712                                           lockdep_is_held(&q->current_entry_lock));
 713         oper = rcu_dereference_protected(q->oper_sched,
 714                                          lockdep_is_held(&q->current_entry_lock));
 715         admin = rcu_dereference_protected(q->admin_sched,
 716                                           lockdep_is_held(&q->current_entry_lock));
 717
 718         if (!oper)
 719                 switch_schedules(q, &admin, &oper);
 720
 721         /* This can happen in two cases: 1. this is the very first run
 722          * of this function (i.e. we weren't running any schedule
 723          * previously); 2. The previous schedule just ended. The first
 724          * entry of all schedules are pre-calculated during the
 725          * schedule initialization.
 726          */
 727         if (unlikely(!entry || entry->close_time == oper->base_time)) {
 728                 next = list_first_entry(&oper->entries, struct sched_entry,
 729                                         list);
 730                 close_time = next->close_time;
 731                 goto first_run;
 732         }
 733
 734         if (should_restart_cycle(oper, entry)) {
 735                 next = list_first_entry(&oper->entries, struct sched_entry,
 736                                         list);
 737                 oper->cycle_close_time = ktime_add_ns(oper->cycle_close_time,
 738                                                       oper->cycle_time);
 739         } else {
 740                 next = list_next_entry(entry, list);
 741         }
 742
 743         close_time = ktime_add_ns(entry->close_time, next->interval);
 744         close_time = min_t(ktime_t, close_time, oper->cycle_close_time);
 745
 746         if (should_change_schedules(admin, oper, close_time)) {
 747                 /* Set things so the next time this runs, the new
 748                  * schedule runs.
 749                  */
 750                 close_time = sched_base_time(admin);
 751                 switch_schedules(q, &admin, &oper);
 752         }
 753
 754         next->close_time = close_time;
 755         taprio_set_budget(q, next);
 756
 757 first_run:
 758         rcu_assign_pointer(q->current_entry, next);
 759         spin_unlock(&q->current_entry_lock);
 760
 761         hrtimer_set_expires(&q->advance_timer, close_time);
 762
 763         rcu_read_lock();
 764         __netif_schedule(sch);
 765         rcu_read_unlock();
 766
 767         return HRTIMER_RESTART;
 768 }
 769
 770 static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = {
 771         [TCA_TAPRIO_SCHED_ENTRY_INDEX]     = { .type = NLA_U32 },
 772         [TCA_TAPRIO_SCHED_ENTRY_CMD]       = { .type = NLA_U8 },
 773         [TCA_TAPRIO_SCHED_ENTRY_GATE_MASK] = { .type = NLA_U32 },
 774         [TCA_TAPRIO_SCHED_ENTRY_INTERVAL]  = { .type = NLA_U32 },
 775 };
 776
 777 static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = {
 778         [TCA_TAPRIO_ATTR_PRIOMAP]              = {
 779                 .len = sizeof(struct tc_mqprio_qopt)
 780         },
 781         [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST]           = { .type = NLA_NESTED },
 782         [TCA_TAPRIO_ATTR_SCHED_BASE_TIME]            = { .type = NLA_S64 },
 783         [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]         = { .type = NLA_NESTED },
 784         [TCA_TAPRIO_ATTR_SCHED_CLOCKID]              = { .type = NLA_S32 },
 785         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]           = { .type = NLA_S64 },
 786         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
 787         [TCA_TAPRIO_ATTR_FLAGS]                      = { .type = NLA_U32 },
 788         [TCA_TAPRIO_ATTR_TXTIME_DELAY]               = { .type = NLA_U32 },
 789 };
 790
 791 static int fill_sched_entry(struct taprio_sched *q, struct nlattr **tb,
 792                             struct sched_entry *entry,
 793                             struct netlink_ext_ack *extack)
 794 {
 795         int min_duration = length_to_duration(q, ETH_ZLEN);
 796         u32 interval = 0;
 797
 798         if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
 799                 entry->command = nla_get_u8(
 800                         tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
 801
 802         if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
 803                 entry->gate_mask = nla_get_u32(
 804                         tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
 805
 806         if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
 807                 interval = nla_get_u32(
 808                         tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
 809
 810         /* The interval should allow at least the minimum ethernet
 811          * frame to go out.
 812          */
 813         if (interval < min_duration) {
 814                 NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
 815                 return -EINVAL;
 816         }
 817
 818         entry->interval = interval;
 819
 820         return 0;
 821 }
 822
 823 static int parse_sched_entry(struct taprio_sched *q, struct nlattr *n,
 824                              struct sched_entry *entry, int index,
 825                              struct netlink_ext_ack *extack)
 826 {
 827         struct nlattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { };
 828         int err;
 829
 830         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, n,
 831                                           entry_policy, NULL);
 832         if (err < 0) {
 833                 NL_SET_ERR_MSG(extack, "Could not parse nested entry");
 834                 return -EINVAL;
 835         }
 836
 837         entry->index = index;
 838
 839         return fill_sched_entry(q, tb, entry, extack);
 840 }
 841
 842 static int parse_sched_list(struct taprio_sched *q, struct nlattr *list,
 843                             struct sched_gate_list *sched,
 844                             struct netlink_ext_ack *extack)
 845 {
 846         struct nlattr *n;
 847         int err, rem;
 848         int i = 0;
 849
 850         if (!list)
 851                 return -EINVAL;
 852
 853         nla_for_each_nested(n, list, rem) {
 854                 struct sched_entry *entry;
 855
 856                 if (nla_type(n) != TCA_TAPRIO_SCHED_ENTRY) {
 857                         NL_SET_ERR_MSG(extack, "Attribute is not of type 'entry'");
 858                         continue;
 859                 }
 860
 861                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 862                 if (!entry) {
 863                         NL_SET_ERR_MSG(extack, "Not enough memory for entry");
 864                         return -ENOMEM;
 865                 }
 866
 867                 err = parse_sched_entry(q, n, entry, i, extack);
 868                 if (err < 0) {
 869                         kfree(entry);
 870                         return err;
 871                 }
 872
 873                 list_add_tail(&entry->list, &sched->entries);
 874                 i++;
 875         }
 876
 877         sched->num_entries = i;
 878
 879         return i;
 880 }
 881
 882 static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
 883                                  struct sched_gate_list *new,
 884                                  struct netlink_ext_ack *extack)
 885 {
 886         int err = 0;
 887
 888         if (tb[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]) {
 889                 NL_SET_ERR_MSG(extack, "Adding a single entry is not supported");
 890                 return -ENOTSUPP;
 891         }
 892
 893         if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
 894                 new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
 895
 896         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
 897                 new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
 898
 899         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
 900                 new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
 901
 902         if (tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST])
 903                 err = parse_sched_list(q, tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST],
 904                                        new, extack);
 905         if (err < 0)
 906                 return err;
 907
 908         if (!new->cycle_time) {
 909                 struct sched_entry *entry;
 910                 ktime_t cycle = 0;
 911
 912                 list_for_each_entry(entry, &new->entries, list)
 913                         cycle = ktime_add_ns(cycle, entry->interval);
 914
 915                 if (!cycle) {
 916                         NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0");
 917                         return -EINVAL;
 918                 }
 919
 920                 new->cycle_time = cycle;
 921         }
 922
 923         return 0;
 924 }
 925
 926 static int taprio_parse_mqprio_opt(struct net_device *dev,
 927                                    struct tc_mqprio_qopt *qopt,
 928                                    struct netlink_ext_ack *extack,
 929                                    u32 taprio_flags)
 930 {
 931         int i, j;
 932
 933         if (!qopt && !dev->num_tc) {
 934                 NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
 935                 return -EINVAL;
 936         }
 937
 938         /* If num_tc is already set, it means that the user already
 939          * configured the mqprio part
 940          */
 941         if (dev->num_tc)
 942                 return 0;
 943
 944         /* Verify num_tc is not out of max range */
 945         if (qopt->num_tc > TC_MAX_QUEUE) {
 946                 NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
 947                 return -EINVAL;
 948         }
 949
 950         /* taprio imposes that traffic classes map 1:n to tx queues */
 951         if (qopt->num_tc > dev->num_tx_queues) {
 952                 NL_SET_ERR_MSG(extack, "Number of traffic classes is greater than number of HW queues");
 953                 return -EINVAL;
 954         }
 955
 956         /* Verify priority mapping uses valid tcs */
 957         for (i = 0; i <= TC_BITMASK; i++) {
 958                 if (qopt->prio_tc_map[i] >= qopt->num_tc) {
 959                         NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping");
 960                         return -EINVAL;
 961                 }
 962         }
 963
 964         for (i = 0; i < qopt->num_tc; i++) {
 965                 unsigned int last = qopt->offset[i] + qopt->count[i];
 966
 967                 /* Verify the queue count is in tx range being equal to the
 968                  * real_num_tx_queues indicates the last queue is in use.
 969                  */
 970                 if (qopt->offset[i] >= dev->num_tx_queues ||
 971                     !qopt->count[i] ||
 972                     last > dev->real_num_tx_queues) {
 973                         NL_SET_ERR_MSG(extack, "Invalid queue in traffic class to queue mapping");
 974                         return -EINVAL;
 975                 }
 976
 977                 if (TXTIME_ASSIST_IS_ENABLED(taprio_flags))
 978                         continue;
 979
 980                 /* Verify that the offset and counts do not overlap */
 981                 for (j = i + 1; j < qopt->num_tc; j++) {
 982                         if (last > qopt->offset[j]) {
 983                                 NL_SET_ERR_MSG(extack, "Detected overlap in the traffic class to queue mapping");
 984                                 return -EINVAL;
 985                         }
 986                 }
 987         }
 988
 989         return 0;
 990 }
 991
 992 static int taprio_get_start_time(struct Qdisc *sch,
 993                                  struct sched_gate_list *sched,
 994                                  ktime_t *start)
 995 {
 996         struct taprio_sched *q = qdisc_priv(sch);
 997         ktime_t now, base, cycle;
 998         s64 n;
 999
1000         base = sched_base_time(sched);
1001         now = taprio_get_time(q);
1002
1003         if (ktime_after(base, now)) {
1004                 *start = base;
1005                 return 0;
1006         }
1007
1008         cycle = sched->cycle_time;
1009
1010         /* The qdisc is expected to have at least one sched_entry.  Moreover,
1011          * any entry must have 'interval' > 0. Thus if the cycle time is zero,
1012          * something went really wrong. In that case, we should warn about this
1013          * inconsistent state and return error.
1014          */
1015         if (WARN_ON(!cycle))
1016                 return -EFAULT;
1017
1018         /* Schedule the start time for the beginning of the next
1019          * cycle.
1020          */
1021         n = div64_s64(ktime_sub_ns(now, base), cycle);
1022         *start = ktime_add_ns(base, (n + 1) * cycle);
1023         return 0;
1024 }
1025
1026 static void setup_first_close_time(struct taprio_sched *q,
1027                                    struct sched_gate_list *sched, ktime_t base)
1028 {
1029         struct sched_entry *first;
1030         ktime_t cycle;
1031
1032         first = list_first_entry(&sched->entries,
1033                                  struct sched_entry, list);
1034
1035         cycle = sched->cycle_time;
1036
1037         /* FIXME: find a better place to do this */
1038         sched->cycle_close_time = ktime_add_ns(base, cycle);
1039
1040         first->close_time = ktime_add_ns(base, first->interval);
1041         taprio_set_budget(q, first);
1042         rcu_assign_pointer(q->current_entry, NULL);
1043 }
1044
1045 static void taprio_start_sched(struct Qdisc *sch,
1046                                ktime_t start, struct sched_gate_list *new)
1047 {
1048         struct taprio_sched *q = qdisc_priv(sch);
1049         ktime_t expires;
1050
1051         if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1052                 return;
1053
1054         expires = hrtimer_get_expires(&q->advance_timer);
1055         if (expires == 0)
1056                 expires = KTIME_MAX;
1057
1058         /* If the new schedule starts before the next expiration, we
1059          * reprogram it to the earliest one, so we change the admin
1060          * schedule to the operational one at the right time.
1061          */
1062         start = min_t(ktime_t, start, expires);
1063
1064         hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS);
1065 }
1066
1067 static void taprio_set_picos_per_byte(struct net_device *dev,
1068                                       struct taprio_sched *q)
1069 {
1070         struct ethtool_link_ksettings ecmd;
1071         int speed = SPEED_10;
1072         int picos_per_byte;
1073         int err;
1074
1075         err = __ethtool_get_link_ksettings(dev, &ecmd);
1076         if (err < 0)
1077                 goto skip;
1078
1079         if (ecmd.base.speed && ecmd.base.speed != SPEED_UNKNOWN)
1080                 speed = ecmd.base.speed;
1081
1082 skip:
1083         picos_per_byte = (USEC_PER_SEC * 8) / speed;
1084
1085         atomic64_set(&q->picos_per_byte, picos_per_byte);
1086         netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
1087                    dev->name, (long long)atomic64_read(&q->picos_per_byte),
1088                    ecmd.base.speed);
1089 }
1090
1091 static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
1092                                void *ptr)
1093 {
1094         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1095         struct net_device *qdev;
1096         struct taprio_sched *q;
1097         bool found = false;
1098
1099         ASSERT_RTNL();
1100
1101         if (event != NETDEV_UP && event != NETDEV_CHANGE)
1102                 return NOTIFY_DONE;
1103
1104         spin_lock(&taprio_list_lock);
1105         list_for_each_entry(q, &taprio_list, taprio_list) {
1106                 qdev = qdisc_dev(q->root);
1107                 if (qdev == dev) {
1108                         found = true;
1109                         break;
1110                 }
1111         }
1112         spin_unlock(&taprio_list_lock);
1113
1114         if (found)
1115                 taprio_set_picos_per_byte(dev, q);
1116
1117         return NOTIFY_DONE;
1118 }
1119
1120 static void setup_txtime(struct taprio_sched *q,
1121                          struct sched_gate_list *sched, ktime_t base)
1122 {
1123         struct sched_entry *entry;
1124         u32 interval = 0;
1125
1126         list_for_each_entry(entry, &sched->entries, list) {
1127                 entry->next_txtime = ktime_add_ns(base, interval);
1128                 interval += entry->interval;
1129         }
1130 }
1131
1132 static struct tc_taprio_qopt_offload *taprio_offload_alloc(int num_entries)
1133 {
1134         struct __tc_taprio_qopt_offload *__offload;
1135
1136         __offload = kzalloc(struct_size(__offload, offload.entries, num_entries),
1137                             GFP_KERNEL);
1138         if (!__offload)
1139                 return NULL;
1140
1141         refcount_set(&__offload->users, 1);
1142
1143         return &__offload->offload;
1144 }
1145
1146 struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
1147                                                   *offload)
1148 {
1149         struct __tc_taprio_qopt_offload *__offload;
1150
1151         __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1152                                  offload);
1153
1154         refcount_inc(&__offload->users);
1155
1156         return offload;
1157 }
1158 EXPORT_SYMBOL_GPL(taprio_offload_get);
1159
1160 void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
1161 {
1162         struct __tc_taprio_qopt_offload *__offload;
1163
1164         __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1165                                  offload);
1166
1167         if (!refcount_dec_and_test(&__offload->users))
1168                 return;
1169
1170         kfree(__offload);
1171 }
1172 EXPORT_SYMBOL_GPL(taprio_offload_free);
1173
1174 /* The function will only serve to keep the pointers to the "oper" and "admin"
1175  * schedules valid in relation to their base times, so when calling dump() the
1176  * users looks at the right schedules.
1177  * When using full offload, the admin configuration is promoted to oper at the
1178  * base_time in the PHC time domain.  But because the system time is not
1179  * necessarily in sync with that, we can't just trigger a hrtimer to call
1180  * switch_schedules at the right hardware time.
1181  * At the moment we call this by hand right away from taprio, but in the future
1182  * it will be useful to create a mechanism for drivers to notify taprio of the
1183  * offload state (PENDING, ACTIVE, INACTIVE) so it can be visible in dump().
1184  * This is left as TODO.
1185  */
1186 static void taprio_offload_config_changed(struct taprio_sched *q)
1187 {
1188         struct sched_gate_list *oper, *admin;
1189
1190         spin_lock(&q->current_entry_lock);
1191
1192         oper = rcu_dereference_protected(q->oper_sched,
1193                                          lockdep_is_held(&q->current_entry_lock));
1194         admin = rcu_dereference_protected(q->admin_sched,
1195                                           lockdep_is_held(&q->current_entry_lock));
1196
1197         switch_schedules(q, &admin, &oper);
1198
1199         spin_unlock(&q->current_entry_lock);
1200 }
1201
1202 static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask)
1203 {
1204         u32 i, queue_mask = 0;
1205
1206         for (i = 0; i < dev->num_tc; i++) {
1207                 u32 offset, count;
1208
1209                 if (!(tc_mask & BIT(i)))
1210                         continue;
1211
1212                 offset = dev->tc_to_txq[i].offset;
1213                 count = dev->tc_to_txq[i].count;
1214
1215                 queue_mask |= GENMASK(offset + count - 1, offset);
1216         }
1217
1218         return queue_mask;
1219 }
1220
1221 static void taprio_sched_to_offload(struct net_device *dev,
1222                                     struct sched_gate_list *sched,
1223                                     struct tc_taprio_qopt_offload *offload)
1224 {
1225         struct sched_entry *entry;
1226         int i = 0;
1227
1228         offload->base_time = sched->base_time;
1229         offload->cycle_time = sched->cycle_time;
1230         offload->cycle_time_extension = sched->cycle_time_extension;
1231
1232         list_for_each_entry(entry, &sched->entries, list) {
1233                 struct tc_taprio_sched_entry *e = &offload->entries[i];
1234
1235                 e->command = entry->command;
1236                 e->interval = entry->interval;
1237                 e->gate_mask = tc_map_to_queue_mask(dev, entry->gate_mask);
1238
1239                 i++;
1240         }
1241
1242         offload->num_entries = i;
1243 }
1244
1245 static int taprio_enable_offload(struct net_device *dev,
1246                                  struct taprio_sched *q,
1247                                  struct sched_gate_list *sched,
1248                                  struct netlink_ext_ack *extack)
1249 {
1250         const struct net_device_ops *ops = dev->netdev_ops;
1251         struct tc_taprio_qopt_offload *offload;
1252         int err = 0;
1253
1254         if (!ops->ndo_setup_tc) {
1255                 NL_SET_ERR_MSG(extack,
1256                                "Device does not support taprio offload");
1257                 return -EOPNOTSUPP;
1258         }
1259
1260         offload = taprio_offload_alloc(sched->num_entries);
1261         if (!offload) {
1262                 NL_SET_ERR_MSG(extack,
1263                                "Not enough memory for enabling offload mode");
1264                 return -ENOMEM;
1265         }
1266         offload->enable = 1;
1267         taprio_sched_to_offload(dev, sched, offload);
1268
1269         err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1270         if (err < 0) {
1271                 NL_SET_ERR_MSG(extack,
1272                                "Device failed to setup taprio offload");
1273                 goto done;
1274         }
1275
1276 done:
1277         taprio_offload_free(offload);
1278
1279         return err;
1280 }
1281
1282 static int taprio_disable_offload(struct net_device *dev,
1283                                   struct taprio_sched *q,
1284                                   struct netlink_ext_ack *extack)
1285 {
1286         const struct net_device_ops *ops = dev->netdev_ops;
1287         struct tc_taprio_qopt_offload *offload;
1288         int err;
1289
1290         if (!FULL_OFFLOAD_IS_ENABLED(q->flags))
1291                 return 0;
1292
1293         if (!ops->ndo_setup_tc)
1294                 return -EOPNOTSUPP;
1295
1296         offload = taprio_offload_alloc(0);
1297         if (!offload) {
1298                 NL_SET_ERR_MSG(extack,
1299                                "Not enough memory to disable offload mode");
1300                 return -ENOMEM;
1301         }
1302         offload->enable = 0;
1303
1304         err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1305         if (err < 0) {
1306                 NL_SET_ERR_MSG(extack,
1307                                "Device failed to disable offload");
1308                 goto out;
1309         }
1310
1311 out:
1312         taprio_offload_free(offload);
1313
1314         return err;
1315 }
1316
1317 /* If full offload is enabled, the only possible clockid is the net device's
1318  * PHC. For that reason, specifying a clockid through netlink is incorrect.
1319  * For txtime-assist, it is implicitly assumed that the device's PHC is kept
1320  * in sync with the specified clockid via a user space daemon such as phc2sys.
1321  * For both software taprio and txtime-assist, the clockid is used for the
1322  * hrtimer that advances the schedule and hence mandatory.
1323  */
1324 static int taprio_parse_clockid(struct Qdisc *sch, struct nlattr **tb,
1325                                 struct netlink_ext_ack *extack)
1326 {
1327         struct taprio_sched *q = qdisc_priv(sch);
1328         struct net_device *dev = qdisc_dev(sch);
1329         int err = -EINVAL;
1330
1331         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1332                 const struct ethtool_ops *ops = dev->ethtool_ops;
1333                 struct ethtool_ts_info info = {
1334                         .cmd = ETHTOOL_GET_TS_INFO,
1335                         .phc_index = -1,
1336                 };
1337
1338                 if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1339                         NL_SET_ERR_MSG(extack,
1340                                        "The 'clockid' cannot be specified for full offload");
1341                         goto out;
1342                 }
1343
1344                 if (ops && ops->get_ts_info)
1345                         err = ops->get_ts_info(dev, &info);
1346
1347                 if (err || info.phc_index < 0) {
1348                         NL_SET_ERR_MSG(extack,
1349                                        "Device does not have a PTP clock");
1350                         err = -ENOTSUPP;
1351                         goto out;
1352                 }
1353         } else if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1354                 int clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
1355
1356                 /* We only support static clockids and we don't allow
1357                  * for it to be modified after the first init.
1358                  */
1359                 if (clockid < 0 ||
1360                     (q->clockid != -1 && q->clockid != clockid)) {
1361                         NL_SET_ERR_MSG(extack,
1362                                        "Changing the 'clockid' of a running schedule is not supported");
1363                         err = -ENOTSUPP;
1364                         goto out;
1365                 }
1366
1367                 switch (clockid) {
1368                 case CLOCK_REALTIME:
1369                         q->tk_offset = TK_OFFS_REAL;
1370                         break;
1371                 case CLOCK_MONOTONIC:
1372                         q->tk_offset = TK_OFFS_MAX;
1373                         break;
1374                 case CLOCK_BOOTTIME:
1375                         q->tk_offset = TK_OFFS_BOOT;
1376                         break;
1377                 case CLOCK_TAI:
1378                         q->tk_offset = TK_OFFS_TAI;
1379                         break;
1380                 default:
1381                         NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
1382                         err = -EINVAL;
1383                         goto out;
1384                 }
1385
1386                 q->clockid = clockid;
1387         } else {
1388                 NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
1389                 goto out;
1390         }
1391
1392         /* Everything went ok, return success. */
1393         err = 0;
1394
1395 out:
1396         return err;
1397 }
1398
1399 static int taprio_mqprio_cmp(const struct net_device *dev,
1400                              const struct tc_mqprio_qopt *mqprio)
1401 {
1402         int i;
1403
1404         if (!mqprio || mqprio->num_tc != dev->num_tc)
1405                 return -1;
1406
1407         for (i = 0; i < mqprio->num_tc; i++)
1408                 if (dev->tc_to_txq[i].count != mqprio->count[i] ||
1409                     dev->tc_to_txq[i].offset != mqprio->offset[i])
1410                         return -1;
1411
1412         for (i = 0; i <= TC_BITMASK; i++)
1413                 if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
1414                         return -1;
1415
1416         return 0;
1417 }
1418
1419 /* The semantics of the 'flags' argument in relation to 'change()'
1420  * requests, are interpreted following two rules (which are applied in
1421  * this order): (1) an omitted 'flags' argument is interpreted as
1422  * zero; (2) the 'flags' of a "running" taprio instance cannot be
1423  * changed.
1424  */
1425 static int taprio_new_flags(const struct nlattr *attr, u32 old,
1426                             struct netlink_ext_ack *extack)
1427 {
1428         u32 new = 0;
1429
1430         if (attr)
1431                 new = nla_get_u32(attr);
1432
1433         if (old != TAPRIO_FLAGS_INVALID && old != new) {
1434                 NL_SET_ERR_MSG_MOD(extack, "Changing 'flags' of a running schedule is not supported");
1435                 return -EOPNOTSUPP;
1436         }
1437
1438         if (!taprio_flags_valid(new)) {
1439                 NL_SET_ERR_MSG_MOD(extack, "Specified 'flags' are not valid");
1440                 return -EINVAL;
1441         }
1442
1443         return new;
1444 }
1445
1446 static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
1447                          struct netlink_ext_ack *extack)
1448 {
1449         struct nlattr *tb[TCA_TAPRIO_ATTR_MAX + 1] = { };
1450         struct sched_gate_list *oper, *admin, *new_admin;
1451         struct taprio_sched *q = qdisc_priv(sch);
1452         struct net_device *dev = qdisc_dev(sch);
1453         struct tc_mqprio_qopt *mqprio = NULL;
1454         unsigned long flags;
1455         ktime_t start;
1456         int i, err;
1457
1458         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_ATTR_MAX, opt,
1459                                           taprio_policy, extack);
1460         if (err < 0)
1461                 return err;
1462
1463         if (tb[TCA_TAPRIO_ATTR_PRIOMAP])
1464                 mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]);
1465
1466         err = taprio_new_flags(tb[TCA_TAPRIO_ATTR_FLAGS],
1467                                q->flags, extack);
1468         if (err < 0)
1469                 return err;
1470
1471         q->flags = err;
1472
1473         err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags);
1474         if (err < 0)
1475                 return err;
1476
1477         new_admin = kzalloc(sizeof(*new_admin), GFP_KERNEL);
1478         if (!new_admin) {
1479                 NL_SET_ERR_MSG(extack, "Not enough memory for a new schedule");
1480                 return -ENOMEM;
1481         }
1482         INIT_LIST_HEAD(&new_admin->entries);
1483
1484         rcu_read_lock();
1485         oper = rcu_dereference(q->oper_sched);
1486         admin = rcu_dereference(q->admin_sched);
1487         rcu_read_unlock();
1488
1489         /* no changes - no new mqprio settings */
1490         if (!taprio_mqprio_cmp(dev, mqprio))
1491                 mqprio = NULL;
1492
1493         if (mqprio && (oper || admin)) {
1494                 NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
1495                 err = -ENOTSUPP;
1496                 goto free_sched;
1497         }
1498
1499         err = parse_taprio_schedule(q, tb, new_admin, extack);
1500         if (err < 0)
1501                 goto free_sched;
1502
1503         if (new_admin->num_entries == 0) {
1504                 NL_SET_ERR_MSG(extack, "There should be at least one entry in the schedule");
1505                 err = -EINVAL;
1506                 goto free_sched;
1507         }
1508
1509         err = taprio_parse_clockid(sch, tb, extack);
1510         if (err < 0)
1511                 goto free_sched;
1512
1513         taprio_set_picos_per_byte(dev, q);
1514
1515         if (mqprio) {
1516                 err = netdev_set_num_tc(dev, mqprio->num_tc);
1517                 if (err)
1518                         goto free_sched;
1519                 for (i = 0; i < mqprio->num_tc; i++)
1520                         netdev_set_tc_queue(dev, i,
1521                                             mqprio->count[i],
1522                                             mqprio->offset[i]);
1523
1524                 /* Always use supplied priority mappings */
1525                 for (i = 0; i <= TC_BITMASK; i++)
1526                         netdev_set_prio_tc_map(dev, i,
1527                                                mqprio->prio_tc_map[i]);
1528         }
1529
1530         if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1531                 err = taprio_enable_offload(dev, q, new_admin, extack);
1532         else
1533                 err = taprio_disable_offload(dev, q, extack);
1534         if (err)
1535                 goto free_sched;
1536
1537         /* Protects against enqueue()/dequeue() */
1538         spin_lock_bh(qdisc_lock(sch));
1539
1540         if (tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]) {
1541                 if (!TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1542                         NL_SET_ERR_MSG_MOD(extack, "txtime-delay can only be set when txtime-assist mode is enabled");
1543                         err = -EINVAL;
1544                         goto unlock;
1545                 }
1546
1547                 q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
1548         }
1549
1550         if (!TXTIME_ASSIST_IS_ENABLED(q->flags) &&
1551             !FULL_OFFLOAD_IS_ENABLED(q->flags) &&
1552             !hrtimer_active(&q->advance_timer)) {
1553                 hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
1554                 q->advance_timer.function = advance_sched;
1555         }
1556
1557         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1558                 q->dequeue = taprio_dequeue_offload;
1559                 q->peek = taprio_peek_offload;
1560         } else {
1561                 /* Be sure to always keep the function pointers
1562                  * in a consistent state.
1563                  */
1564                 q->dequeue = taprio_dequeue_soft;
1565                 q->peek = taprio_peek_soft;
1566         }
1567
1568         err = taprio_get_start_time(sch, new_admin, &start);
1569         if (err < 0) {
1570                 NL_SET_ERR_MSG(extack, "Internal error: failed get start time");
1571                 goto unlock;
1572         }
1573
1574         setup_txtime(q, new_admin, start);
1575
1576         if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1577                 if (!oper) {
1578                         rcu_assign_pointer(q->oper_sched, new_admin);
1579                         err = 0;
1580                         new_admin = NULL;
1581                         goto unlock;
1582                 }
1583
1584                 rcu_assign_pointer(q->admin_sched, new_admin);
1585                 if (admin)
1586                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1587         } else {
1588                 setup_first_close_time(q, new_admin, start);
1589
1590                 /* Protects against advance_sched() */
1591                 spin_lock_irqsave(&q->current_entry_lock, flags);
1592
1593                 taprio_start_sched(sch, start, new_admin);
1594
1595                 rcu_assign_pointer(q->admin_sched, new_admin);
1596                 if (admin)
1597                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1598
1599                 spin_unlock_irqrestore(&q->current_entry_lock, flags);
1600
1601                 if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1602                         taprio_offload_config_changed(q);
1603         }
1604
1605         new_admin = NULL;
1606         err = 0;
1607
1608 unlock:
1609         spin_unlock_bh(qdisc_lock(sch));
1610
1611 free_sched:
1612         if (new_admin)
1613                 call_rcu(&new_admin->rcu, taprio_free_sched_cb);
1614
1615         return err;
1616 }
1617
1618 static void taprio_reset(struct Qdisc *sch)
1619 {
1620         struct taprio_sched *q = qdisc_priv(sch);
1621         struct net_device *dev = qdisc_dev(sch);
1622         int i;
1623
1624         hrtimer_cancel(&q->advance_timer);
1625         if (q->qdiscs) {
1626                 for (i = 0; i < dev->num_tx_queues; i++)
1627                         if (q->qdiscs[i])
1628                                 qdisc_reset(q->qdiscs[i]);
1629         }
1630         sch->qstats.backlog = 0;
1631         sch->q.qlen = 0;
1632 }
1633
1634 static void taprio_destroy(struct Qdisc *sch)
1635 {
1636         struct taprio_sched *q = qdisc_priv(sch);
1637         struct net_device *dev = qdisc_dev(sch);
1638         unsigned int i;
1639
1640         spin_lock(&taprio_list_lock);
1641         list_del(&q->taprio_list);
1642         spin_unlock(&taprio_list_lock);
1643
1644         /* Note that taprio_reset() might not be called if an error
1645          * happens in qdisc_create(), after taprio_init() has been called.
1646          */
1647         hrtimer_cancel(&q->advance_timer);
1648
1649         taprio_disable_offload(dev, q, NULL);
1650
1651         if (q->qdiscs) {
1652                 for (i = 0; i < dev->num_tx_queues; i++)
1653                         qdisc_put(q->qdiscs[i]);
1654
1655                 kfree(q->qdiscs);
1656         }
1657         q->qdiscs = NULL;
1658
1659         netdev_reset_tc(dev);
1660
1661         if (q->oper_sched)
1662                 call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);
1663
1664         if (q->admin_sched)
1665                 call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb);
1666 }
1667
1668 static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
1669                        struct netlink_ext_ack *extack)
1670 {
1671         struct taprio_sched *q = qdisc_priv(sch);
1672         struct net_device *dev = qdisc_dev(sch);
1673         int i;
1674
1675         spin_lock_init(&q->current_entry_lock);
1676
1677         hrtimer_init(&q->advance_timer, CLOCK_TAI, HRTIMER_MODE_ABS);
1678         q->advance_timer.function = advance_sched;
1679
1680         q->dequeue = taprio_dequeue_soft;
1681         q->peek = taprio_peek_soft;
1682
1683         q->root = sch;
1684
1685         /* We only support static clockids. Use an invalid value as default
1686          * and get the valid one on taprio_change().
1687          */
1688         q->clockid = -1;
1689         q->flags = TAPRIO_FLAGS_INVALID;
1690
1691         spin_lock(&taprio_list_lock);
1692         list_add(&q->taprio_list, &taprio_list);
1693         spin_unlock(&taprio_list_lock);
1694
1695         if (sch->parent != TC_H_ROOT)
1696                 return -EOPNOTSUPP;
1697
1698         if (!netif_is_multiqueue(dev))
1699                 return -EOPNOTSUPP;
1700
1701         /* pre-allocate qdisc, attachment can't fail */
1702         q->qdiscs = kcalloc(dev->num_tx_queues,
1703                             sizeof(q->qdiscs[0]),
1704                             GFP_KERNEL);
1705
1706         if (!q->qdiscs)
1707                 return -ENOMEM;
1708
1709         if (!opt)
1710                 return -EINVAL;
1711
1712         for (i = 0; i < dev->num_tx_queues; i++) {
1713                 struct netdev_queue *dev_queue;
1714                 struct Qdisc *qdisc;
1715
1716                 dev_queue = netdev_get_tx_queue(dev, i);
1717                 qdisc = qdisc_create_dflt(dev_queue,
1718                                           &pfifo_qdisc_ops,
1719                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
1720                                                     TC_H_MIN(i + 1)),
1721                                           extack);
1722                 if (!qdisc)
1723                         return -ENOMEM;
1724
1725                 if (i < dev->real_num_tx_queues)
1726                         qdisc_hash_add(qdisc, false);
1727
1728                 q->qdiscs[i] = qdisc;
1729         }
1730
1731         return taprio_change(sch, opt, extack);
1732 }
1733
1734 static void taprio_attach(struct Qdisc *sch)
1735 {
1736         struct taprio_sched *q = qdisc_priv(sch);
1737         struct net_device *dev = qdisc_dev(sch);
1738         unsigned int ntx;
1739
1740         /* Attach underlying qdisc */
1741         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
1742                 struct Qdisc *qdisc = q->qdiscs[ntx];
1743                 struct Qdisc *old;
1744
1745                 if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1746                         qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1747                         old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
1748                 } else {
1749                         old = dev_graft_qdisc(qdisc->dev_queue, sch);
1750                         qdisc_refcount_inc(sch);
1751                 }
1752                 if (old)
1753                         qdisc_put(old);
1754         }
1755
1756         /* access to the child qdiscs is not needed in offload mode */
1757         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1758                 kfree(q->qdiscs);
1759                 q->qdiscs = NULL;
1760         }
1761 }
1762
1763 static struct netdev_queue *taprio_queue_get(struct Qdisc *sch,
1764                                              unsigned long cl)
1765 {
1766         struct net_device *dev = qdisc_dev(sch);
1767         unsigned long ntx = cl - 1;
1768
1769         if (ntx >= dev->num_tx_queues)
1770                 return NULL;
1771
1772         return netdev_get_tx_queue(dev, ntx);
1773 }
1774
1775 static int taprio_graft(struct Qdisc *sch, unsigned long cl,
1776                         struct Qdisc *new, struct Qdisc **old,
1777                         struct netlink_ext_ack *extack)
1778 {
1779         struct taprio_sched *q = qdisc_priv(sch);
1780         struct net_device *dev = qdisc_dev(sch);
1781         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1782
1783         if (!dev_queue)
1784                 return -EINVAL;
1785
1786         if (dev->flags & IFF_UP)
1787                 dev_deactivate(dev);
1788
1789         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1790                 *old = dev_graft_qdisc(dev_queue, new);
1791         } else {
1792                 *old = q->qdiscs[cl - 1];
1793                 q->qdiscs[cl - 1] = new;
1794         }
1795
1796         if (new)
1797                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1798
1799         if (dev->flags & IFF_UP)
1800                 dev_activate(dev);
1801
1802         return 0;
1803 }
1804
1805 static int dump_entry(struct sk_buff *msg,
1806                       const struct sched_entry *entry)
1807 {
1808         struct nlattr *item;
1809
1810         item = nla_nest_start_noflag(msg, TCA_TAPRIO_SCHED_ENTRY);
1811         if (!item)
1812                 return -ENOSPC;
1813
1814         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INDEX, entry->index))
1815                 goto nla_put_failure;
1816
1817         if (nla_put_u8(msg, TCA_TAPRIO_SCHED_ENTRY_CMD, entry->command))
1818                 goto nla_put_failure;
1819
1820         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_GATE_MASK,
1821                         entry->gate_mask))
1822                 goto nla_put_failure;
1823
1824         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INTERVAL,
1825                         entry->interval))
1826                 goto nla_put_failure;
1827
1828         return nla_nest_end(msg, item);
1829
1830 nla_put_failure:
1831         nla_nest_cancel(msg, item);
1832         return -1;
1833 }
1834
1835 static int dump_schedule(struct sk_buff *msg,
1836                          const struct sched_gate_list *root)
1837 {
1838         struct nlattr *entry_list;
1839         struct sched_entry *entry;
1840
1841         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_BASE_TIME,
1842                         root->base_time, TCA_TAPRIO_PAD))
1843                 return -1;
1844
1845         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME,
1846                         root->cycle_time, TCA_TAPRIO_PAD))
1847                 return -1;
1848
1849         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION,
1850                         root->cycle_time_extension, TCA_TAPRIO_PAD))
1851                 return -1;
1852
1853         entry_list = nla_nest_start_noflag(msg,
1854                                            TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST);
1855         if (!entry_list)
1856                 goto error_nest;
1857
1858         list_for_each_entry(entry, &root->entries, list) {
1859                 if (dump_entry(msg, entry) < 0)
1860                         goto error_nest;
1861         }
1862
1863         nla_nest_end(msg, entry_list);
1864         return 0;
1865
1866 error_nest:
1867         nla_nest_cancel(msg, entry_list);
1868         return -1;
1869 }
1870
1871 static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
1872 {
1873         struct taprio_sched *q = qdisc_priv(sch);
1874         struct net_device *dev = qdisc_dev(sch);
1875         struct sched_gate_list *oper, *admin;
1876         struct tc_mqprio_qopt opt = { 0 };
1877         struct nlattr *nest, *sched_nest;
1878         unsigned int i;
1879
1880         rcu_read_lock();
1881         oper = rcu_dereference(q->oper_sched);
1882         admin = rcu_dereference(q->admin_sched);
1883
1884         opt.num_tc = netdev_get_num_tc(dev);
1885         memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
1886
1887         for (i = 0; i < netdev_get_num_tc(dev); i++) {
1888                 opt.count[i] = dev->tc_to_txq[i].count;
1889                 opt.offset[i] = dev->tc_to_txq[i].offset;
1890         }
1891
1892         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1893         if (!nest)
1894                 goto start_error;
1895
1896         if (nla_put(skb, TCA_TAPRIO_ATTR_PRIOMAP, sizeof(opt), &opt))
1897                 goto options_error;
1898
1899         if (!FULL_OFFLOAD_IS_ENABLED(q->flags) &&
1900             nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
1901                 goto options_error;
1902
1903         if (q->flags && nla_put_u32(skb, TCA_TAPRIO_ATTR_FLAGS, q->flags))
1904                 goto options_error;
1905
1906         if (q->txtime_delay &&
1907             nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
1908                 goto options_error;
1909
1910         if (oper && dump_schedule(skb, oper))
1911                 goto options_error;
1912
1913         if (!admin)
1914                 goto done;
1915
1916         sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
1917         if (!sched_nest)
1918                 goto options_error;
1919
1920         if (dump_schedule(skb, admin))
1921                 goto admin_error;
1922
1923         nla_nest_end(skb, sched_nest);
1924
1925 done:
1926         rcu_read_unlock();
1927
1928         return nla_nest_end(skb, nest);
1929
1930 admin_error:
1931         nla_nest_cancel(skb, sched_nest);
1932
1933 options_error:
1934         nla_nest_cancel(skb, nest);
1935
1936 start_error:
1937         rcu_read_unlock();
1938         return -ENOSPC;
1939 }
1940
1941 static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
1942 {
1943         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1944
1945         if (!dev_queue)
1946                 return NULL;
1947
1948         return dev_queue->qdisc_sleeping;
1949 }
1950
1951 static unsigned long taprio_find(struct Qdisc *sch, u32 classid)
1952 {
1953         unsigned int ntx = TC_H_MIN(classid);
1954
1955         if (!taprio_queue_get(sch, ntx))
1956                 return 0;
1957         return ntx;
1958 }
1959
1960 static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
1961                              struct sk_buff *skb, struct tcmsg *tcm)
1962 {
1963         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1964
1965         tcm->tcm_parent = TC_H_ROOT;
1966         tcm->tcm_handle |= TC_H_MIN(cl);
1967         tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
1968
1969         return 0;
1970 }
1971
1972 static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
1973                                    struct gnet_dump *d)
1974         __releases(d->lock)
1975         __acquires(d->lock)
1976 {
1977         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1978
1979         sch = dev_queue->qdisc_sleeping;
1980         if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
1981             qdisc_qstats_copy(d, sch) < 0)
1982                 return -1;
1983         return 0;
1984 }
1985
1986 static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1987 {
1988         struct net_device *dev = qdisc_dev(sch);
1989         unsigned long ntx;
1990
1991         if (arg->stop)
1992                 return;
1993
1994         arg->count = arg->skip;
1995         for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
1996                 if (arg->fn(sch, ntx + 1, arg) < 0) {
1997                         arg->stop = 1;
1998                         break;
1999                 }
2000                 arg->count++;
2001         }
2002 }
2003
2004 static struct netdev_queue *taprio_select_queue(struct Qdisc *sch,
2005                                                 struct tcmsg *tcm)
2006 {
2007         return taprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
2008 }
2009
2010 static const struct Qdisc_class_ops taprio_class_ops = {
2011         .graft          = taprio_graft,
2012         .leaf           = taprio_leaf,
2013         .find           = taprio_find,
2014         .walk           = taprio_walk,
2015         .dump           = taprio_dump_class,
2016         .dump_stats     = taprio_dump_class_stats,
2017         .select_queue   = taprio_select_queue,
2018 };
2019
2020 static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
2021         .cl_ops         = &taprio_class_ops,
2022         .id             = "taprio",
2023         .priv_size      = sizeof(struct taprio_sched),
2024         .init           = taprio_init,
2025         .change         = taprio_change,
2026         .destroy        = taprio_destroy,
2027         .reset          = taprio_reset,
2028         .attach         = taprio_attach,
2029         .peek           = taprio_peek,
2030         .dequeue        = taprio_dequeue,
2031         .enqueue        = taprio_enqueue,
2032         .dump           = taprio_dump,
2033         .owner          = THIS_MODULE,
2034 };
2035
2036 static struct notifier_block taprio_device_notifier = {
2037         .notifier_call = taprio_dev_notifier,
2038 };
2039
2040 static int __init taprio_module_init(void)
2041 {
2042         int err = register_netdevice_notifier(&taprio_device_notifier);
2043
2044         if (err)
2045                 return err;
2046
2047         return register_qdisc(&taprio_qdisc_ops);
2048 }
2049
2050 static void __exit taprio_module_exit(void)
2051 {
2052         unregister_qdisc(&taprio_qdisc_ops);
2053         unregister_netdevice_notifier(&taprio_device_notifier);
2054 }
2055
2056 module_init(taprio_module_init);
2057 module_exit(taprio_module_exit);
2058 MODULE_LICENSE("GPL");