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