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/ethtool_netlink.h>
  11 #include <linux/types.h>
  12 #include <linux/slab.h>
  13 #include <linux/kernel.h>
  14 #include <linux/string.h>
  15 #include <linux/list.h>
  16 #include <linux/errno.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/math64.h>
  19 #include <linux/module.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/rcupdate.h>
  22 #include <linux/time.h>
  23 #include <net/gso.h>
  24 #include <net/netlink.h>
  25 #include <net/pkt_sched.h>
  26 #include <net/pkt_cls.h>
  27 #include <net/sch_generic.h>
  28 #include <net/sock.h>
  29 #include <net/tcp.h>
  30
  31 #define TAPRIO_STAT_NOT_SET     (~0ULL)
  32
  33 #include "sch_mqprio_lib.h"
  34
  35 static LIST_HEAD(taprio_list);
  36 static struct static_key_false taprio_have_broken_mqprio;
  37 static struct static_key_false taprio_have_working_mqprio;
  38
  39 #define TAPRIO_ALL_GATES_OPEN -1
  40
  41 #define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST)
  42 #define FULL_OFFLOAD_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
  43 #define TAPRIO_SUPPORTED_FLAGS \
  44         (TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST | TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
  45 #define TAPRIO_FLAGS_INVALID U32_MAX
  46
  47 struct sched_entry {
  48         /* Durations between this GCL entry and the GCL entry where the
  49          * respective traffic class gate closes
  50          */
  51         u64 gate_duration[TC_MAX_QUEUE];
  52         atomic_t budget[TC_MAX_QUEUE];
  53         /* The qdisc makes some effort so that no packet leaves
  54          * after this time
  55          */
  56         ktime_t gate_close_time[TC_MAX_QUEUE];
  57         struct list_head list;
  58         /* Used to calculate when to advance the schedule */
  59         ktime_t end_time;
  60         ktime_t next_txtime;
  61         int index;
  62         u32 gate_mask;
  63         u32 interval;
  64         u8 command;
  65 };
  66
  67 struct sched_gate_list {
  68         /* Longest non-zero contiguous gate durations per traffic class,
  69          * or 0 if a traffic class gate never opens during the schedule.
  70          */
  71         u64 max_open_gate_duration[TC_MAX_QUEUE];
  72         u32 max_frm_len[TC_MAX_QUEUE]; /* for the fast path */
  73         u32 max_sdu[TC_MAX_QUEUE]; /* for dump */
  74         struct rcu_head rcu;
  75         struct list_head entries;
  76         size_t num_entries;
  77         ktime_t cycle_end_time;
  78         s64 cycle_time;
  79         s64 cycle_time_extension;
  80         s64 base_time;
  81 };
  82
  83 struct taprio_sched {
  84         struct Qdisc **qdiscs;
  85         struct Qdisc *root;
  86         u32 flags;
  87         enum tk_offsets tk_offset;
  88         int clockid;
  89         bool offloaded;
  90         bool detected_mqprio;
  91         bool broken_mqprio;
  92         atomic64_t picos_per_byte; /* Using picoseconds because for 10Gbps+
  93                                     * speeds it's sub-nanoseconds per byte
  94                                     */
  95
  96         /* Protects the update side of the RCU protected current_entry */
  97         spinlock_t current_entry_lock;
  98         struct sched_entry __rcu *current_entry;
  99         struct sched_gate_list __rcu *oper_sched;
 100         struct sched_gate_list __rcu *admin_sched;
 101         struct hrtimer advance_timer;
 102         struct list_head taprio_list;
 103         int cur_txq[TC_MAX_QUEUE];
 104         u32 max_sdu[TC_MAX_QUEUE]; /* save info from the user */
 105         u32 fp[TC_QOPT_MAX_QUEUE]; /* only for dump and offloading */
 106         u32 txtime_delay;
 107 };
 108
 109 struct __tc_taprio_qopt_offload {
 110         refcount_t users;
 111         struct tc_taprio_qopt_offload offload;
 112 };
 113
 114 static void taprio_calculate_gate_durations(struct taprio_sched *q,
 115                                             struct sched_gate_list *sched)
 116 {
 117         struct net_device *dev = qdisc_dev(q->root);
 118         int num_tc = netdev_get_num_tc(dev);
 119         struct sched_entry *entry, *cur;
 120         int tc;
 121
 122         list_for_each_entry(entry, &sched->entries, list) {
 123                 u32 gates_still_open = entry->gate_mask;
 124
 125                 /* For each traffic class, calculate each open gate duration,
 126                  * starting at this schedule entry and ending at the schedule
 127                  * entry containing a gate close event for that TC.
 128                  */
 129                 cur = entry;
 130
 131                 do {
 132                         if (!gates_still_open)
 133                                 break;
 134
 135                         for (tc = 0; tc < num_tc; tc++) {
 136                                 if (!(gates_still_open & BIT(tc)))
 137                                         continue;
 138
 139                                 if (cur->gate_mask & BIT(tc))
 140                                         entry->gate_duration[tc] += cur->interval;
 141                                 else
 142                                         gates_still_open &= ~BIT(tc);
 143                         }
 144
 145                         cur = list_next_entry_circular(cur, &sched->entries, list);
 146                 } while (cur != entry);
 147
 148                 /* Keep track of the maximum gate duration for each traffic
 149                  * class, taking care to not confuse a traffic class which is
 150                  * temporarily closed with one that is always closed.
 151                  */
 152                 for (tc = 0; tc < num_tc; tc++)
 153                         if (entry->gate_duration[tc] &&
 154                             sched->max_open_gate_duration[tc] < entry->gate_duration[tc])
 155                                 sched->max_open_gate_duration[tc] = entry->gate_duration[tc];
 156         }
 157 }
 158
 159 static bool taprio_entry_allows_tx(ktime_t skb_end_time,
 160                                    struct sched_entry *entry, int tc)
 161 {
 162         return ktime_before(skb_end_time, entry->gate_close_time[tc]);
 163 }
 164
 165 static ktime_t sched_base_time(const struct sched_gate_list *sched)
 166 {
 167         if (!sched)
 168                 return KTIME_MAX;
 169
 170         return ns_to_ktime(sched->base_time);
 171 }
 172
 173 static ktime_t taprio_mono_to_any(const struct taprio_sched *q, ktime_t mono)
 174 {
 175         /* This pairs with WRITE_ONCE() in taprio_parse_clockid() */
 176         enum tk_offsets tk_offset = READ_ONCE(q->tk_offset);
 177
 178         switch (tk_offset) {
 179         case TK_OFFS_MAX:
 180                 return mono;
 181         default:
 182                 return ktime_mono_to_any(mono, tk_offset);
 183         }
 184 }
 185
 186 static ktime_t taprio_get_time(const struct taprio_sched *q)
 187 {
 188         return taprio_mono_to_any(q, ktime_get());
 189 }
 190
 191 static void taprio_free_sched_cb(struct rcu_head *head)
 192 {
 193         struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
 194         struct sched_entry *entry, *n;
 195
 196         list_for_each_entry_safe(entry, n, &sched->entries, list) {
 197                 list_del(&entry->list);
 198                 kfree(entry);
 199         }
 200
 201         kfree(sched);
 202 }
 203
 204 static void switch_schedules(struct taprio_sched *q,
 205                              struct sched_gate_list **admin,
 206                              struct sched_gate_list **oper)
 207 {
 208         rcu_assign_pointer(q->oper_sched, *admin);
 209         rcu_assign_pointer(q->admin_sched, NULL);
 210
 211         if (*oper)
 212                 call_rcu(&(*oper)->rcu, taprio_free_sched_cb);
 213
 214         *oper = *admin;
 215         *admin = NULL;
 216 }
 217
 218 /* Get how much time has been already elapsed in the current cycle. */
 219 static s32 get_cycle_time_elapsed(struct sched_gate_list *sched, ktime_t time)
 220 {
 221         ktime_t time_since_sched_start;
 222         s32 time_elapsed;
 223
 224         time_since_sched_start = ktime_sub(time, sched->base_time);
 225         div_s64_rem(time_since_sched_start, sched->cycle_time, &time_elapsed);
 226
 227         return time_elapsed;
 228 }
 229
 230 static ktime_t get_interval_end_time(struct sched_gate_list *sched,
 231                                      struct sched_gate_list *admin,
 232                                      struct sched_entry *entry,
 233                                      ktime_t intv_start)
 234 {
 235         s32 cycle_elapsed = get_cycle_time_elapsed(sched, intv_start);
 236         ktime_t intv_end, cycle_ext_end, cycle_end;
 237
 238         cycle_end = ktime_add_ns(intv_start, sched->cycle_time - cycle_elapsed);
 239         intv_end = ktime_add_ns(intv_start, entry->interval);
 240         cycle_ext_end = ktime_add(cycle_end, sched->cycle_time_extension);
 241
 242         if (ktime_before(intv_end, cycle_end))
 243                 return intv_end;
 244         else if (admin && admin != sched &&
 245                  ktime_after(admin->base_time, cycle_end) &&
 246                  ktime_before(admin->base_time, cycle_ext_end))
 247                 return admin->base_time;
 248         else
 249                 return cycle_end;
 250 }
 251
 252 static int length_to_duration(struct taprio_sched *q, int len)
 253 {
 254         return div_u64(len * atomic64_read(&q->picos_per_byte), PSEC_PER_NSEC);
 255 }
 256
 257 static int duration_to_length(struct taprio_sched *q, u64 duration)
 258 {
 259         return div_u64(duration * PSEC_PER_NSEC, atomic64_read(&q->picos_per_byte));
 260 }
 261
 262 /* Sets sched->max_sdu[] and sched->max_frm_len[] to the minimum between the
 263  * q->max_sdu[] requested by the user and the max_sdu dynamically determined by
 264  * the maximum open gate durations at the given link speed.
 265  */
 266 static void taprio_update_queue_max_sdu(struct taprio_sched *q,
 267                                         struct sched_gate_list *sched,
 268                                         struct qdisc_size_table *stab)
 269 {
 270         struct net_device *dev = qdisc_dev(q->root);
 271         int num_tc = netdev_get_num_tc(dev);
 272         u32 max_sdu_from_user;
 273         u32 max_sdu_dynamic;
 274         u32 max_sdu;
 275         int tc;
 276
 277         for (tc = 0; tc < num_tc; tc++) {
 278                 max_sdu_from_user = q->max_sdu[tc] ?: U32_MAX;
 279
 280                 /* TC gate never closes => keep the queueMaxSDU
 281                  * selected by the user
 282                  */
 283                 if (sched->max_open_gate_duration[tc] == sched->cycle_time) {
 284                         max_sdu_dynamic = U32_MAX;
 285                 } else {
 286                         u32 max_frm_len;
 287
 288                         max_frm_len = duration_to_length(q, sched->max_open_gate_duration[tc]);
 289                         /* Compensate for L1 overhead from size table,
 290                          * but don't let the frame size go negative
 291                          */
 292                         if (stab) {
 293                                 max_frm_len -= stab->szopts.overhead;
 294                                 max_frm_len = max_t(int, max_frm_len,
 295                                                     dev->hard_header_len + 1);
 296                         }
 297                         max_sdu_dynamic = max_frm_len - dev->hard_header_len;
 298                         if (max_sdu_dynamic > dev->max_mtu)
 299                                 max_sdu_dynamic = U32_MAX;
 300                 }
 301
 302                 max_sdu = min(max_sdu_dynamic, max_sdu_from_user);
 303
 304                 if (max_sdu != U32_MAX) {
 305                         sched->max_frm_len[tc] = max_sdu + dev->hard_header_len;
 306                         sched->max_sdu[tc] = max_sdu;
 307                 } else {
 308                         sched->max_frm_len[tc] = U32_MAX; /* never oversized */
 309                         sched->max_sdu[tc] = 0;
 310                 }
 311         }
 312 }
 313
 314 /* Returns the entry corresponding to next available interval. If
 315  * validate_interval is set, it only validates whether the timestamp occurs
 316  * when the gate corresponding to the skb's traffic class is open.
 317  */
 318 static struct sched_entry *find_entry_to_transmit(struct sk_buff *skb,
 319                                                   struct Qdisc *sch,
 320                                                   struct sched_gate_list *sched,
 321                                                   struct sched_gate_list *admin,
 322                                                   ktime_t time,
 323                                                   ktime_t *interval_start,
 324                                                   ktime_t *interval_end,
 325                                                   bool validate_interval)
 326 {
 327         ktime_t curr_intv_start, curr_intv_end, cycle_end, packet_transmit_time;
 328         ktime_t earliest_txtime = KTIME_MAX, txtime, cycle, transmit_end_time;
 329         struct sched_entry *entry = NULL, *entry_found = NULL;
 330         struct taprio_sched *q = qdisc_priv(sch);
 331         struct net_device *dev = qdisc_dev(sch);
 332         bool entry_available = false;
 333         s32 cycle_elapsed;
 334         int tc, n;
 335
 336         tc = netdev_get_prio_tc_map(dev, skb->priority);
 337         packet_transmit_time = length_to_duration(q, qdisc_pkt_len(skb));
 338
 339         *interval_start = 0;
 340         *interval_end = 0;
 341
 342         if (!sched)
 343                 return NULL;
 344
 345         cycle = sched->cycle_time;
 346         cycle_elapsed = get_cycle_time_elapsed(sched, time);
 347         curr_intv_end = ktime_sub_ns(time, cycle_elapsed);
 348         cycle_end = ktime_add_ns(curr_intv_end, cycle);
 349
 350         list_for_each_entry(entry, &sched->entries, list) {
 351                 curr_intv_start = curr_intv_end;
 352                 curr_intv_end = get_interval_end_time(sched, admin, entry,
 353                                                       curr_intv_start);
 354
 355                 if (ktime_after(curr_intv_start, cycle_end))
 356                         break;
 357
 358                 if (!(entry->gate_mask & BIT(tc)) ||
 359                     packet_transmit_time > entry->interval)
 360                         continue;
 361
 362                 txtime = entry->next_txtime;
 363
 364                 if (ktime_before(txtime, time) || validate_interval) {
 365                         transmit_end_time = ktime_add_ns(time, packet_transmit_time);
 366                         if ((ktime_before(curr_intv_start, time) &&
 367                              ktime_before(transmit_end_time, curr_intv_end)) ||
 368                             (ktime_after(curr_intv_start, time) && !validate_interval)) {
 369                                 entry_found = entry;
 370                                 *interval_start = curr_intv_start;
 371                                 *interval_end = curr_intv_end;
 372                                 break;
 373                         } else if (!entry_available && !validate_interval) {
 374                                 /* Here, we are just trying to find out the
 375                                  * first available interval in the next cycle.
 376                                  */
 377                                 entry_available = true;
 378                                 entry_found = entry;
 379                                 *interval_start = ktime_add_ns(curr_intv_start, cycle);
 380                                 *interval_end = ktime_add_ns(curr_intv_end, cycle);
 381                         }
 382                 } else if (ktime_before(txtime, earliest_txtime) &&
 383                            !entry_available) {
 384                         earliest_txtime = txtime;
 385                         entry_found = entry;
 386                         n = div_s64(ktime_sub(txtime, curr_intv_start), cycle);
 387                         *interval_start = ktime_add(curr_intv_start, n * cycle);
 388                         *interval_end = ktime_add(curr_intv_end, n * cycle);
 389                 }
 390         }
 391
 392         return entry_found;
 393 }
 394
 395 static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
 396 {
 397         struct taprio_sched *q = qdisc_priv(sch);
 398         struct sched_gate_list *sched, *admin;
 399         ktime_t interval_start, interval_end;
 400         struct sched_entry *entry;
 401
 402         rcu_read_lock();
 403         sched = rcu_dereference(q->oper_sched);
 404         admin = rcu_dereference(q->admin_sched);
 405
 406         entry = find_entry_to_transmit(skb, sch, sched, admin, skb->tstamp,
 407                                        &interval_start, &interval_end, true);
 408         rcu_read_unlock();
 409
 410         return entry;
 411 }
 412
 413 /* This returns the tstamp value set by TCP in terms of the set clock. */
 414 static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
 415 {
 416         unsigned int offset = skb_network_offset(skb);
 417         const struct ipv6hdr *ipv6h;
 418         const struct iphdr *iph;
 419         struct ipv6hdr _ipv6h;
 420
 421         ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
 422         if (!ipv6h)
 423                 return 0;
 424
 425         if (ipv6h->version == 4) {
 426                 iph = (struct iphdr *)ipv6h;
 427                 offset += iph->ihl * 4;
 428
 429                 /* special-case 6in4 tunnelling, as that is a common way to get
 430                  * v6 connectivity in the home
 431                  */
 432                 if (iph->protocol == IPPROTO_IPV6) {
 433                         ipv6h = skb_header_pointer(skb, offset,
 434                                                    sizeof(_ipv6h), &_ipv6h);
 435
 436                         if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
 437                                 return 0;
 438                 } else if (iph->protocol != IPPROTO_TCP) {
 439                         return 0;
 440                 }
 441         } else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
 442                 return 0;
 443         }
 444
 445         return taprio_mono_to_any(q, skb->skb_mstamp_ns);
 446 }
 447
 448 /* There are a few scenarios where we will have to modify the txtime from
 449  * what is read from next_txtime in sched_entry. They are:
 450  * 1. If txtime is in the past,
 451  *    a. The gate for the traffic class is currently open and packet can be
 452  *       transmitted before it closes, schedule the packet right away.
 453  *    b. If the gate corresponding to the traffic class is going to open later
 454  *       in the cycle, set the txtime of packet to the interval start.
 455  * 2. If txtime is in the future, there are packets corresponding to the
 456  *    current traffic class waiting to be transmitted. So, the following
 457  *    possibilities exist:
 458  *    a. We can transmit the packet before the window containing the txtime
 459  *       closes.
 460  *    b. The window might close before the transmission can be completed
 461  *       successfully. So, schedule the packet in the next open window.
 462  */
 463 static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 464 {
 465         ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
 466         struct taprio_sched *q = qdisc_priv(sch);
 467         struct sched_gate_list *sched, *admin;
 468         ktime_t minimum_time, now, txtime;
 469         int len, packet_transmit_time;
 470         struct sched_entry *entry;
 471         bool sched_changed;
 472
 473         now = taprio_get_time(q);
 474         minimum_time = ktime_add_ns(now, q->txtime_delay);
 475
 476         tcp_tstamp = get_tcp_tstamp(q, skb);
 477         minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
 478
 479         rcu_read_lock();
 480         admin = rcu_dereference(q->admin_sched);
 481         sched = rcu_dereference(q->oper_sched);
 482         if (admin && ktime_after(minimum_time, admin->base_time))
 483                 switch_schedules(q, &admin, &sched);
 484
 485         /* Until the schedule starts, all the queues are open */
 486         if (!sched || ktime_before(minimum_time, sched->base_time)) {
 487                 txtime = minimum_time;
 488                 goto done;
 489         }
 490
 491         len = qdisc_pkt_len(skb);
 492         packet_transmit_time = length_to_duration(q, len);
 493
 494         do {
 495                 sched_changed = false;
 496
 497                 entry = find_entry_to_transmit(skb, sch, sched, admin,
 498                                                minimum_time,
 499                                                &interval_start, &interval_end,
 500                                                false);
 501                 if (!entry) {
 502                         txtime = 0;
 503                         goto done;
 504                 }
 505
 506                 txtime = entry->next_txtime;
 507                 txtime = max_t(ktime_t, txtime, minimum_time);
 508                 txtime = max_t(ktime_t, txtime, interval_start);
 509
 510                 if (admin && admin != sched &&
 511                     ktime_after(txtime, admin->base_time)) {
 512                         sched = admin;
 513                         sched_changed = true;
 514                         continue;
 515                 }
 516
 517                 transmit_end_time = ktime_add(txtime, packet_transmit_time);
 518                 minimum_time = transmit_end_time;
 519
 520                 /* Update the txtime of current entry to the next time it's
 521                  * interval starts.
 522                  */
 523                 if (ktime_after(transmit_end_time, interval_end))
 524                         entry->next_txtime = ktime_add(interval_start, sched->cycle_time);
 525         } while (sched_changed || ktime_after(transmit_end_time, interval_end));
 526
 527         entry->next_txtime = transmit_end_time;
 528
 529 done:
 530         rcu_read_unlock();
 531         return txtime;
 532 }
 533
 534 /* Devices with full offload are expected to honor this in hardware */
 535 static bool taprio_skb_exceeds_queue_max_sdu(struct Qdisc *sch,
 536                                              struct sk_buff *skb)
 537 {
 538         struct taprio_sched *q = qdisc_priv(sch);
 539         struct net_device *dev = qdisc_dev(sch);
 540         struct sched_gate_list *sched;
 541         int prio = skb->priority;
 542         bool exceeds = false;
 543         u8 tc;
 544
 545         tc = netdev_get_prio_tc_map(dev, prio);
 546
 547         rcu_read_lock();
 548         sched = rcu_dereference(q->oper_sched);
 549         if (sched && skb->len > sched->max_frm_len[tc])
 550                 exceeds = true;
 551         rcu_read_unlock();
 552
 553         return exceeds;
 554 }
 555
 556 static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch,
 557                               struct Qdisc *child, struct sk_buff **to_free)
 558 {
 559         struct taprio_sched *q = qdisc_priv(sch);
 560
 561         /* sk_flags are only safe to use on full sockets. */
 562         if (skb->sk && sk_fullsock(skb->sk) && sock_flag(skb->sk, SOCK_TXTIME)) {
 563                 if (!is_valid_interval(skb, sch))
 564                         return qdisc_drop(skb, sch, to_free);
 565         } else if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 566                 skb->tstamp = get_packet_txtime(skb, sch);
 567                 if (!skb->tstamp)
 568                         return qdisc_drop(skb, sch, to_free);
 569         }
 570
 571         qdisc_qstats_backlog_inc(sch, skb);
 572         sch->q.qlen++;
 573
 574         return qdisc_enqueue(skb, child, to_free);
 575 }
 576
 577 static int taprio_enqueue_segmented(struct sk_buff *skb, struct Qdisc *sch,
 578                                     struct Qdisc *child,
 579                                     struct sk_buff **to_free)
 580 {
 581         unsigned int slen = 0, numsegs = 0, len = qdisc_pkt_len(skb);
 582         netdev_features_t features = netif_skb_features(skb);
 583         struct sk_buff *segs, *nskb;
 584         int ret;
 585
 586         segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
 587         if (IS_ERR_OR_NULL(segs))
 588                 return qdisc_drop(skb, sch, to_free);
 589
 590         skb_list_walk_safe(segs, segs, nskb) {
 591                 skb_mark_not_on_list(segs);
 592                 qdisc_skb_cb(segs)->pkt_len = segs->len;
 593                 slen += segs->len;
 594
 595                 /* FIXME: we should be segmenting to a smaller size
 596                  * rather than dropping these
 597                  */
 598                 if (taprio_skb_exceeds_queue_max_sdu(sch, segs))
 599                         ret = qdisc_drop(segs, sch, to_free);
 600                 else
 601                         ret = taprio_enqueue_one(segs, sch, child, to_free);
 602
 603                 if (ret != NET_XMIT_SUCCESS) {
 604                         if (net_xmit_drop_count(ret))
 605                                 qdisc_qstats_drop(sch);
 606                 } else {
 607                         numsegs++;
 608                 }
 609         }
 610
 611         if (numsegs > 1)
 612                 qdisc_tree_reduce_backlog(sch, 1 - numsegs, len - slen);
 613         consume_skb(skb);
 614
 615         return numsegs > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 616 }
 617
 618 /* Will not be called in the full offload case, since the TX queues are
 619  * attached to the Qdisc created using qdisc_create_dflt()
 620  */
 621 static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 622                           struct sk_buff **to_free)
 623 {
 624         struct taprio_sched *q = qdisc_priv(sch);
 625         struct Qdisc *child;
 626         int queue;
 627
 628         queue = skb_get_queue_mapping(skb);
 629
 630         child = q->qdiscs[queue];
 631         if (unlikely(!child))
 632                 return qdisc_drop(skb, sch, to_free);
 633
 634         if (taprio_skb_exceeds_queue_max_sdu(sch, skb)) {
 635                 /* Large packets might not be transmitted when the transmission
 636                  * duration exceeds any configured interval. Therefore, segment
 637                  * the skb into smaller chunks. Drivers with full offload are
 638                  * expected to handle this in hardware.
 639                  */
 640                 if (skb_is_gso(skb))
 641                         return taprio_enqueue_segmented(skb, sch, child,
 642                                                         to_free);
 643
 644                 return qdisc_drop(skb, sch, to_free);
 645         }
 646
 647         return taprio_enqueue_one(skb, sch, child, to_free);
 648 }
 649
 650 static struct sk_buff *taprio_peek(struct Qdisc *sch)
 651 {
 652         WARN_ONCE(1, "taprio only supports operating as root qdisc, peek() not implemented");
 653         return NULL;
 654 }
 655
 656 static void taprio_set_budgets(struct taprio_sched *q,
 657                                struct sched_gate_list *sched,
 658                                struct sched_entry *entry)
 659 {
 660         struct net_device *dev = qdisc_dev(q->root);
 661         int num_tc = netdev_get_num_tc(dev);
 662         int tc, budget;
 663
 664         for (tc = 0; tc < num_tc; tc++) {
 665                 /* Traffic classes which never close have infinite budget */
 666                 if (entry->gate_duration[tc] == sched->cycle_time)
 667                         budget = INT_MAX;
 668                 else
 669                         budget = div64_u64((u64)entry->gate_duration[tc] * PSEC_PER_NSEC,
 670                                            atomic64_read(&q->picos_per_byte));
 671
 672                 atomic_set(&entry->budget[tc], budget);
 673         }
 674 }
 675
 676 /* When an skb is sent, it consumes from the budget of all traffic classes */
 677 static int taprio_update_budgets(struct sched_entry *entry, size_t len,
 678                                  int tc_consumed, int num_tc)
 679 {
 680         int tc, budget, new_budget = 0;
 681
 682         for (tc = 0; tc < num_tc; tc++) {
 683                 budget = atomic_read(&entry->budget[tc]);
 684                 /* Don't consume from infinite budget */
 685                 if (budget == INT_MAX) {
 686                         if (tc == tc_consumed)
 687                                 new_budget = budget;
 688                         continue;
 689                 }
 690
 691                 if (tc == tc_consumed)
 692                         new_budget = atomic_sub_return(len, &entry->budget[tc]);
 693                 else
 694                         atomic_sub(len, &entry->budget[tc]);
 695         }
 696
 697         return new_budget;
 698 }
 699
 700 static struct sk_buff *taprio_dequeue_from_txq(struct Qdisc *sch, int txq,
 701                                                struct sched_entry *entry,
 702                                                u32 gate_mask)
 703 {
 704         struct taprio_sched *q = qdisc_priv(sch);
 705         struct net_device *dev = qdisc_dev(sch);
 706         struct Qdisc *child = q->qdiscs[txq];
 707         int num_tc = netdev_get_num_tc(dev);
 708         struct sk_buff *skb;
 709         ktime_t guard;
 710         int prio;
 711         int len;
 712         u8 tc;
 713
 714         if (unlikely(!child))
 715                 return NULL;
 716
 717         if (TXTIME_ASSIST_IS_ENABLED(q->flags))
 718                 goto skip_peek_checks;
 719
 720         skb = child->ops->peek(child);
 721         if (!skb)
 722                 return NULL;
 723
 724         prio = skb->priority;
 725         tc = netdev_get_prio_tc_map(dev, prio);
 726
 727         if (!(gate_mask & BIT(tc)))
 728                 return NULL;
 729
 730         len = qdisc_pkt_len(skb);
 731         guard = ktime_add_ns(taprio_get_time(q), length_to_duration(q, len));
 732
 733         /* In the case that there's no gate entry, there's no
 734          * guard band ...
 735          */
 736         if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 737             !taprio_entry_allows_tx(guard, entry, tc))
 738                 return NULL;
 739
 740         /* ... and no budget. */
 741         if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 742             taprio_update_budgets(entry, len, tc, num_tc) < 0)
 743                 return NULL;
 744
 745 skip_peek_checks:
 746         skb = child->ops->dequeue(child);
 747         if (unlikely(!skb))
 748                 return NULL;
 749
 750         qdisc_bstats_update(sch, skb);
 751         qdisc_qstats_backlog_dec(sch, skb);
 752         sch->q.qlen--;
 753
 754         return skb;
 755 }
 756
 757 static void taprio_next_tc_txq(struct net_device *dev, int tc, int *txq)
 758 {
 759         int offset = dev->tc_to_txq[tc].offset;
 760         int count = dev->tc_to_txq[tc].count;
 761
 762         (*txq)++;
 763         if (*txq == offset + count)
 764                 *txq = offset;
 765 }
 766
 767 /* Prioritize higher traffic classes, and select among TXQs belonging to the
 768  * same TC using round robin
 769  */
 770 static struct sk_buff *taprio_dequeue_tc_priority(struct Qdisc *sch,
 771                                                   struct sched_entry *entry,
 772                                                   u32 gate_mask)
 773 {
 774         struct taprio_sched *q = qdisc_priv(sch);
 775         struct net_device *dev = qdisc_dev(sch);
 776         int num_tc = netdev_get_num_tc(dev);
 777         struct sk_buff *skb;
 778         int tc;
 779
 780         for (tc = num_tc - 1; tc >= 0; tc--) {
 781                 int first_txq = q->cur_txq[tc];
 782
 783                 if (!(gate_mask & BIT(tc)))
 784                         continue;
 785
 786                 do {
 787                         skb = taprio_dequeue_from_txq(sch, q->cur_txq[tc],
 788                                                       entry, gate_mask);
 789
 790                         taprio_next_tc_txq(dev, tc, &q->cur_txq[tc]);
 791
 792                         if (q->cur_txq[tc] >= dev->num_tx_queues)
 793                                 q->cur_txq[tc] = first_txq;
 794
 795                         if (skb)
 796                                 return skb;
 797                 } while (q->cur_txq[tc] != first_txq);
 798         }
 799
 800         return NULL;
 801 }
 802
 803 /* Broken way of prioritizing smaller TXQ indices and ignoring the traffic
 804  * class other than to determine whether the gate is open or not
 805  */
 806 static struct sk_buff *taprio_dequeue_txq_priority(struct Qdisc *sch,
 807                                                    struct sched_entry *entry,
 808                                                    u32 gate_mask)
 809 {
 810         struct net_device *dev = qdisc_dev(sch);
 811         struct sk_buff *skb;
 812         int i;
 813
 814         for (i = 0; i < dev->num_tx_queues; i++) {
 815                 skb = taprio_dequeue_from_txq(sch, i, entry, gate_mask);
 816                 if (skb)
 817                         return skb;
 818         }
 819
 820         return NULL;
 821 }
 822
 823 /* Will not be called in the full offload case, since the TX queues are
 824  * attached to the Qdisc created using qdisc_create_dflt()
 825  */
 826 static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 827 {
 828         struct taprio_sched *q = qdisc_priv(sch);
 829         struct sk_buff *skb = NULL;
 830         struct sched_entry *entry;
 831         u32 gate_mask;
 832
 833         rcu_read_lock();
 834         entry = rcu_dereference(q->current_entry);
 835         /* if there's no entry, it means that the schedule didn't
 836          * start yet, so force all gates to be open, this is in
 837          * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5
 838          * "AdminGateStates"
 839          */
 840         gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 841         if (!gate_mask)
 842                 goto done;
 843
 844         if (static_branch_unlikely(&taprio_have_broken_mqprio) &&
 845             !static_branch_likely(&taprio_have_working_mqprio)) {
 846                 /* Single NIC kind which is broken */
 847                 skb = taprio_dequeue_txq_priority(sch, entry, gate_mask);
 848         } else if (static_branch_likely(&taprio_have_working_mqprio) &&
 849                    !static_branch_unlikely(&taprio_have_broken_mqprio)) {
 850                 /* Single NIC kind which prioritizes properly */
 851                 skb = taprio_dequeue_tc_priority(sch, entry, gate_mask);
 852         } else {
 853                 /* Mixed NIC kinds present in system, need dynamic testing */
 854                 if (q->broken_mqprio)
 855                         skb = taprio_dequeue_txq_priority(sch, entry, gate_mask);
 856                 else
 857                         skb = taprio_dequeue_tc_priority(sch, entry, gate_mask);
 858         }
 859
 860 done:
 861         rcu_read_unlock();
 862
 863         return skb;
 864 }
 865
 866 static bool should_restart_cycle(const struct sched_gate_list *oper,
 867                                  const struct sched_entry *entry)
 868 {
 869         if (list_is_last(&entry->list, &oper->entries))
 870                 return true;
 871
 872         if (ktime_compare(entry->end_time, oper->cycle_end_time) == 0)
 873                 return true;
 874
 875         return false;
 876 }
 877
 878 static bool should_change_schedules(const struct sched_gate_list *admin,
 879                                     const struct sched_gate_list *oper,
 880                                     ktime_t end_time)
 881 {
 882         ktime_t next_base_time, extension_time;
 883
 884         if (!admin)
 885                 return false;
 886
 887         next_base_time = sched_base_time(admin);
 888
 889         /* This is the simple case, the end_time would fall after
 890          * the next schedule base_time.
 891          */
 892         if (ktime_compare(next_base_time, end_time) <= 0)
 893                 return true;
 894
 895         /* This is the cycle_time_extension case, if the end_time
 896          * plus the amount that can be extended would fall after the
 897          * next schedule base_time, we can extend the current schedule
 898          * for that amount.
 899          */
 900         extension_time = ktime_add_ns(end_time, oper->cycle_time_extension);
 901
 902         /* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about
 903          * how precisely the extension should be made. So after
 904          * conformance testing, this logic may change.
 905          */
 906         if (ktime_compare(next_base_time, extension_time) <= 0)
 907                 return true;
 908
 909         return false;
 910 }
 911
 912 static enum hrtimer_restart advance_sched(struct hrtimer *timer)
 913 {
 914         struct taprio_sched *q = container_of(timer, struct taprio_sched,
 915                                               advance_timer);
 916         struct net_device *dev = qdisc_dev(q->root);
 917         struct sched_gate_list *oper, *admin;
 918         int num_tc = netdev_get_num_tc(dev);
 919         struct sched_entry *entry, *next;
 920         struct Qdisc *sch = q->root;
 921         ktime_t end_time;
 922         int tc;
 923
 924         spin_lock(&q->current_entry_lock);
 925         entry = rcu_dereference_protected(q->current_entry,
 926                                           lockdep_is_held(&q->current_entry_lock));
 927         oper = rcu_dereference_protected(q->oper_sched,
 928                                          lockdep_is_held(&q->current_entry_lock));
 929         admin = rcu_dereference_protected(q->admin_sched,
 930                                           lockdep_is_held(&q->current_entry_lock));
 931
 932         if (!oper)
 933                 switch_schedules(q, &admin, &oper);
 934
 935         /* This can happen in two cases: 1. this is the very first run
 936          * of this function (i.e. we weren't running any schedule
 937          * previously); 2. The previous schedule just ended. The first
 938          * entry of all schedules are pre-calculated during the
 939          * schedule initialization.
 940          */
 941         if (unlikely(!entry || entry->end_time == oper->base_time)) {
 942                 next = list_first_entry(&oper->entries, struct sched_entry,
 943                                         list);
 944                 end_time = next->end_time;
 945                 goto first_run;
 946         }
 947
 948         if (should_restart_cycle(oper, entry)) {
 949                 next = list_first_entry(&oper->entries, struct sched_entry,
 950                                         list);
 951                 oper->cycle_end_time = ktime_add_ns(oper->cycle_end_time,
 952                                                     oper->cycle_time);
 953         } else {
 954                 next = list_next_entry(entry, list);
 955         }
 956
 957         end_time = ktime_add_ns(entry->end_time, next->interval);
 958         end_time = min_t(ktime_t, end_time, oper->cycle_end_time);
 959
 960         for (tc = 0; tc < num_tc; tc++) {
 961                 if (next->gate_duration[tc] == oper->cycle_time)
 962                         next->gate_close_time[tc] = KTIME_MAX;
 963                 else
 964                         next->gate_close_time[tc] = ktime_add_ns(entry->end_time,
 965                                                                  next->gate_duration[tc]);
 966         }
 967
 968         if (should_change_schedules(admin, oper, end_time)) {
 969                 /* Set things so the next time this runs, the new
 970                  * schedule runs.
 971                  */
 972                 end_time = sched_base_time(admin);
 973                 switch_schedules(q, &admin, &oper);
 974         }
 975
 976         next->end_time = end_time;
 977         taprio_set_budgets(q, oper, next);
 978
 979 first_run:
 980         rcu_assign_pointer(q->current_entry, next);
 981         spin_unlock(&q->current_entry_lock);
 982
 983         hrtimer_set_expires(&q->advance_timer, end_time);
 984
 985         rcu_read_lock();
 986         __netif_schedule(sch);
 987         rcu_read_unlock();
 988
 989         return HRTIMER_RESTART;
 990 }
 991
 992 static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = {
 993         [TCA_TAPRIO_SCHED_ENTRY_INDEX]     = { .type = NLA_U32 },
 994         [TCA_TAPRIO_SCHED_ENTRY_CMD]       = { .type = NLA_U8 },
 995         [TCA_TAPRIO_SCHED_ENTRY_GATE_MASK] = { .type = NLA_U32 },
 996         [TCA_TAPRIO_SCHED_ENTRY_INTERVAL]  = { .type = NLA_U32 },
 997 };
 998
 999 static const struct nla_policy taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = {
1000         [TCA_TAPRIO_TC_ENTRY_INDEX]        = NLA_POLICY_MAX(NLA_U32,
1001                                                             TC_QOPT_MAX_QUEUE),
1002         [TCA_TAPRIO_TC_ENTRY_MAX_SDU]      = { .type = NLA_U32 },
1003         [TCA_TAPRIO_TC_ENTRY_FP]           = NLA_POLICY_RANGE(NLA_U32,
1004                                                               TC_FP_EXPRESS,
1005                                                               TC_FP_PREEMPTIBLE),
1006 };
1007
1008 static const struct netlink_range_validation_signed taprio_cycle_time_range = {
1009         .min = 0,
1010         .max = INT_MAX,
1011 };
1012
1013 static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = {
1014         [TCA_TAPRIO_ATTR_PRIOMAP]              = {
1015                 .len = sizeof(struct tc_mqprio_qopt)
1016         },
1017         [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST]           = { .type = NLA_NESTED },
1018         [TCA_TAPRIO_ATTR_SCHED_BASE_TIME]            = { .type = NLA_S64 },
1019         [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]         = { .type = NLA_NESTED },
1020         [TCA_TAPRIO_ATTR_SCHED_CLOCKID]              = { .type = NLA_S32 },
1021         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]           =
1022                 NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range),
1023         [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
1024         [TCA_TAPRIO_ATTR_FLAGS]                      =
1025                 NLA_POLICY_MASK(NLA_U32, TAPRIO_SUPPORTED_FLAGS),
1026         [TCA_TAPRIO_ATTR_TXTIME_DELAY]               = { .type = NLA_U32 },
1027         [TCA_TAPRIO_ATTR_TC_ENTRY]                   = { .type = NLA_NESTED },
1028 };
1029
1030 static int fill_sched_entry(struct taprio_sched *q, struct nlattr **tb,
1031                             struct sched_entry *entry,
1032                             struct netlink_ext_ack *extack)
1033 {
1034         int min_duration = length_to_duration(q, ETH_ZLEN);
1035         u32 interval = 0;
1036
1037         if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
1038                 entry->command = nla_get_u8(
1039                         tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
1040
1041         if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
1042                 entry->gate_mask = nla_get_u32(
1043                         tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
1044
1045         if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
1046                 interval = nla_get_u32(
1047                         tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
1048
1049         /* The interval should allow at least the minimum ethernet
1050          * frame to go out.
1051          */
1052         if (interval < min_duration) {
1053                 NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
1054                 return -EINVAL;
1055         }
1056
1057         entry->interval = interval;
1058
1059         return 0;
1060 }
1061
1062 static int parse_sched_entry(struct taprio_sched *q, struct nlattr *n,
1063                              struct sched_entry *entry, int index,
1064                              struct netlink_ext_ack *extack)
1065 {
1066         struct nlattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { };
1067         int err;
1068
1069         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, n,
1070                                           entry_policy, NULL);
1071         if (err < 0) {
1072                 NL_SET_ERR_MSG(extack, "Could not parse nested entry");
1073                 return -EINVAL;
1074         }
1075
1076         entry->index = index;
1077
1078         return fill_sched_entry(q, tb, entry, extack);
1079 }
1080
1081 static int parse_sched_list(struct taprio_sched *q, struct nlattr *list,
1082                             struct sched_gate_list *sched,
1083                             struct netlink_ext_ack *extack)
1084 {
1085         struct nlattr *n;
1086         int err, rem;
1087         int i = 0;
1088
1089         if (!list)
1090                 return -EINVAL;
1091
1092         nla_for_each_nested(n, list, rem) {
1093                 struct sched_entry *entry;
1094
1095                 if (nla_type(n) != TCA_TAPRIO_SCHED_ENTRY) {
1096                         NL_SET_ERR_MSG(extack, "Attribute is not of type 'entry'");
1097                         continue;
1098                 }
1099
1100                 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1101                 if (!entry) {
1102                         NL_SET_ERR_MSG(extack, "Not enough memory for entry");
1103                         return -ENOMEM;
1104                 }
1105
1106                 err = parse_sched_entry(q, n, entry, i, extack);
1107                 if (err < 0) {
1108                         kfree(entry);
1109                         return err;
1110                 }
1111
1112                 list_add_tail(&entry->list, &sched->entries);
1113                 i++;
1114         }
1115
1116         sched->num_entries = i;
1117
1118         return i;
1119 }
1120
1121 static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
1122                                  struct sched_gate_list *new,
1123                                  struct netlink_ext_ack *extack)
1124 {
1125         int err = 0;
1126
1127         if (tb[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]) {
1128                 NL_SET_ERR_MSG(extack, "Adding a single entry is not supported");
1129                 return -ENOTSUPP;
1130         }
1131
1132         if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
1133                 new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
1134
1135         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
1136                 new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
1137
1138         if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
1139                 new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
1140
1141         if (tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST])
1142                 err = parse_sched_list(q, tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST],
1143                                        new, extack);
1144         if (err < 0)
1145                 return err;
1146
1147         if (!new->cycle_time) {
1148                 struct sched_entry *entry;
1149                 ktime_t cycle = 0;
1150
1151                 list_for_each_entry(entry, &new->entries, list)
1152                         cycle = ktime_add_ns(cycle, entry->interval);
1153
1154                 if (cycle < 0 || cycle > INT_MAX) {
1155                         NL_SET_ERR_MSG(extack, "'cycle_time' is too big");
1156                         return -EINVAL;
1157                 }
1158
1159                 new->cycle_time = cycle;
1160         }
1161
1162         if (new->cycle_time < new->num_entries * length_to_duration(q, ETH_ZLEN)) {
1163                 NL_SET_ERR_MSG(extack, "'cycle_time' is too small");
1164                 return -EINVAL;
1165         }
1166
1167         taprio_calculate_gate_durations(q, new);
1168
1169         return 0;
1170 }
1171
1172 static int taprio_parse_mqprio_opt(struct net_device *dev,
1173                                    struct tc_mqprio_qopt *qopt,
1174                                    struct netlink_ext_ack *extack,
1175                                    u32 taprio_flags)
1176 {
1177         bool allow_overlapping_txqs = TXTIME_ASSIST_IS_ENABLED(taprio_flags);
1178
1179         if (!qopt) {
1180                 if (!dev->num_tc) {
1181                         NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
1182                         return -EINVAL;
1183                 }
1184                 return 0;
1185         }
1186
1187         /* taprio imposes that traffic classes map 1:n to tx queues */
1188         if (qopt->num_tc > dev->num_tx_queues) {
1189                 NL_SET_ERR_MSG(extack, "Number of traffic classes is greater than number of HW queues");
1190                 return -EINVAL;
1191         }
1192
1193         /* For some reason, in txtime-assist mode, we allow TXQ ranges for
1194          * different TCs to overlap, and just validate the TXQ ranges.
1195          */
1196         return mqprio_validate_qopt(dev, qopt, true, allow_overlapping_txqs,
1197                                     extack);
1198 }
1199
1200 static int taprio_get_start_time(struct Qdisc *sch,
1201                                  struct sched_gate_list *sched,
1202                                  ktime_t *start)
1203 {
1204         struct taprio_sched *q = qdisc_priv(sch);
1205         ktime_t now, base, cycle;
1206         s64 n;
1207
1208         base = sched_base_time(sched);
1209         now = taprio_get_time(q);
1210
1211         if (ktime_after(base, now)) {
1212                 *start = base;
1213                 return 0;
1214         }
1215
1216         cycle = sched->cycle_time;
1217
1218         /* The qdisc is expected to have at least one sched_entry.  Moreover,
1219          * any entry must have 'interval' > 0. Thus if the cycle time is zero,
1220          * something went really wrong. In that case, we should warn about this
1221          * inconsistent state and return error.
1222          */
1223         if (WARN_ON(!cycle))
1224                 return -EFAULT;
1225
1226         /* Schedule the start time for the beginning of the next
1227          * cycle.
1228          */
1229         n = div64_s64(ktime_sub_ns(now, base), cycle);
1230         *start = ktime_add_ns(base, (n + 1) * cycle);
1231         return 0;
1232 }
1233
1234 static void setup_first_end_time(struct taprio_sched *q,
1235                                  struct sched_gate_list *sched, ktime_t base)
1236 {
1237         struct net_device *dev = qdisc_dev(q->root);
1238         int num_tc = netdev_get_num_tc(dev);
1239         struct sched_entry *first;
1240         ktime_t cycle;
1241         int tc;
1242
1243         first = list_first_entry(&sched->entries,
1244                                  struct sched_entry, list);
1245
1246         cycle = sched->cycle_time;
1247
1248         /* FIXME: find a better place to do this */
1249         sched->cycle_end_time = ktime_add_ns(base, cycle);
1250
1251         first->end_time = ktime_add_ns(base, first->interval);
1252         taprio_set_budgets(q, sched, first);
1253
1254         for (tc = 0; tc < num_tc; tc++) {
1255                 if (first->gate_duration[tc] == sched->cycle_time)
1256                         first->gate_close_time[tc] = KTIME_MAX;
1257                 else
1258                         first->gate_close_time[tc] = ktime_add_ns(base, first->gate_duration[tc]);
1259         }
1260
1261         rcu_assign_pointer(q->current_entry, NULL);
1262 }
1263
1264 static void taprio_start_sched(struct Qdisc *sch,
1265                                ktime_t start, struct sched_gate_list *new)
1266 {
1267         struct taprio_sched *q = qdisc_priv(sch);
1268         ktime_t expires;
1269
1270         if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1271                 return;
1272
1273         expires = hrtimer_get_expires(&q->advance_timer);
1274         if (expires == 0)
1275                 expires = KTIME_MAX;
1276
1277         /* If the new schedule starts before the next expiration, we
1278          * reprogram it to the earliest one, so we change the admin
1279          * schedule to the operational one at the right time.
1280          */
1281         start = min_t(ktime_t, start, expires);
1282
1283         hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS);
1284 }
1285
1286 static void taprio_set_picos_per_byte(struct net_device *dev,
1287                                       struct taprio_sched *q)
1288 {
1289         struct ethtool_link_ksettings ecmd;
1290         int speed = SPEED_10;
1291         int picos_per_byte;
1292         int err;
1293
1294         err = __ethtool_get_link_ksettings(dev, &ecmd);
1295         if (err < 0)
1296                 goto skip;
1297
1298         if (ecmd.base.speed && ecmd.base.speed != SPEED_UNKNOWN)
1299                 speed = ecmd.base.speed;
1300
1301 skip:
1302         picos_per_byte = (USEC_PER_SEC * 8) / speed;
1303
1304         atomic64_set(&q->picos_per_byte, picos_per_byte);
1305         netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
1306                    dev->name, (long long)atomic64_read(&q->picos_per_byte),
1307                    ecmd.base.speed);
1308 }
1309
1310 static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
1311                                void *ptr)
1312 {
1313         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1314         struct sched_gate_list *oper, *admin;
1315         struct qdisc_size_table *stab;
1316         struct taprio_sched *q;
1317
1318         ASSERT_RTNL();
1319
1320         if (event != NETDEV_UP && event != NETDEV_CHANGE)
1321                 return NOTIFY_DONE;
1322
1323         list_for_each_entry(q, &taprio_list, taprio_list) {
1324                 if (dev != qdisc_dev(q->root))
1325                         continue;
1326
1327                 taprio_set_picos_per_byte(dev, q);
1328
1329                 stab = rtnl_dereference(q->root->stab);
1330
1331                 oper = rtnl_dereference(q->oper_sched);
1332                 if (oper)
1333                         taprio_update_queue_max_sdu(q, oper, stab);
1334
1335                 admin = rtnl_dereference(q->admin_sched);
1336                 if (admin)
1337                         taprio_update_queue_max_sdu(q, admin, stab);
1338
1339                 break;
1340         }
1341
1342         return NOTIFY_DONE;
1343 }
1344
1345 static void setup_txtime(struct taprio_sched *q,
1346                          struct sched_gate_list *sched, ktime_t base)
1347 {
1348         struct sched_entry *entry;
1349         u64 interval = 0;
1350
1351         list_for_each_entry(entry, &sched->entries, list) {
1352                 entry->next_txtime = ktime_add_ns(base, interval);
1353                 interval += entry->interval;
1354         }
1355 }
1356
1357 static struct tc_taprio_qopt_offload *taprio_offload_alloc(int num_entries)
1358 {
1359         struct __tc_taprio_qopt_offload *__offload;
1360
1361         __offload = kzalloc(struct_size(__offload, offload.entries, num_entries),
1362                             GFP_KERNEL);
1363         if (!__offload)
1364                 return NULL;
1365
1366         refcount_set(&__offload->users, 1);
1367
1368         return &__offload->offload;
1369 }
1370
1371 struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
1372                                                   *offload)
1373 {
1374         struct __tc_taprio_qopt_offload *__offload;
1375
1376         __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1377                                  offload);
1378
1379         refcount_inc(&__offload->users);
1380
1381         return offload;
1382 }
1383 EXPORT_SYMBOL_GPL(taprio_offload_get);
1384
1385 void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
1386 {
1387         struct __tc_taprio_qopt_offload *__offload;
1388
1389         __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1390                                  offload);
1391
1392         if (!refcount_dec_and_test(&__offload->users))
1393                 return;
1394
1395         kfree(__offload);
1396 }
1397 EXPORT_SYMBOL_GPL(taprio_offload_free);
1398
1399 /* The function will only serve to keep the pointers to the "oper" and "admin"
1400  * schedules valid in relation to their base times, so when calling dump() the
1401  * users looks at the right schedules.
1402  * When using full offload, the admin configuration is promoted to oper at the
1403  * base_time in the PHC time domain.  But because the system time is not
1404  * necessarily in sync with that, we can't just trigger a hrtimer to call
1405  * switch_schedules at the right hardware time.
1406  * At the moment we call this by hand right away from taprio, but in the future
1407  * it will be useful to create a mechanism for drivers to notify taprio of the
1408  * offload state (PENDING, ACTIVE, INACTIVE) so it can be visible in dump().
1409  * This is left as TODO.
1410  */
1411 static void taprio_offload_config_changed(struct taprio_sched *q)
1412 {
1413         struct sched_gate_list *oper, *admin;
1414
1415         oper = rtnl_dereference(q->oper_sched);
1416         admin = rtnl_dereference(q->admin_sched);
1417
1418         switch_schedules(q, &admin, &oper);
1419 }
1420
1421 static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask)
1422 {
1423         u32 i, queue_mask = 0;
1424
1425         for (i = 0; i < dev->num_tc; i++) {
1426                 u32 offset, count;
1427
1428                 if (!(tc_mask & BIT(i)))
1429                         continue;
1430
1431                 offset = dev->tc_to_txq[i].offset;
1432                 count = dev->tc_to_txq[i].count;
1433
1434                 queue_mask |= GENMASK(offset + count - 1, offset);
1435         }
1436
1437         return queue_mask;
1438 }
1439
1440 static void taprio_sched_to_offload(struct net_device *dev,
1441                                     struct sched_gate_list *sched,
1442                                     struct tc_taprio_qopt_offload *offload,
1443                                     const struct tc_taprio_caps *caps)
1444 {
1445         struct sched_entry *entry;
1446         int i = 0;
1447
1448         offload->base_time = sched->base_time;
1449         offload->cycle_time = sched->cycle_time;
1450         offload->cycle_time_extension = sched->cycle_time_extension;
1451
1452         list_for_each_entry(entry, &sched->entries, list) {
1453                 struct tc_taprio_sched_entry *e = &offload->entries[i];
1454
1455                 e->command = entry->command;
1456                 e->interval = entry->interval;
1457                 if (caps->gate_mask_per_txq)
1458                         e->gate_mask = tc_map_to_queue_mask(dev,
1459                                                             entry->gate_mask);
1460                 else
1461                         e->gate_mask = entry->gate_mask;
1462
1463                 i++;
1464         }
1465
1466         offload->num_entries = i;
1467 }
1468
1469 static void taprio_detect_broken_mqprio(struct taprio_sched *q)
1470 {
1471         struct net_device *dev = qdisc_dev(q->root);
1472         struct tc_taprio_caps caps;
1473
1474         qdisc_offload_query_caps(dev, TC_SETUP_QDISC_TAPRIO,
1475                                  &caps, sizeof(caps));
1476
1477         q->broken_mqprio = caps.broken_mqprio;
1478         if (q->broken_mqprio)
1479                 static_branch_inc(&taprio_have_broken_mqprio);
1480         else
1481                 static_branch_inc(&taprio_have_working_mqprio);
1482
1483         q->detected_mqprio = true;
1484 }
1485
1486 static void taprio_cleanup_broken_mqprio(struct taprio_sched *q)
1487 {
1488         if (!q->detected_mqprio)
1489                 return;
1490
1491         if (q->broken_mqprio)
1492                 static_branch_dec(&taprio_have_broken_mqprio);
1493         else
1494                 static_branch_dec(&taprio_have_working_mqprio);
1495 }
1496
1497 static int taprio_enable_offload(struct net_device *dev,
1498                                  struct taprio_sched *q,
1499                                  struct sched_gate_list *sched,
1500                                  struct netlink_ext_ack *extack)
1501 {
1502         const struct net_device_ops *ops = dev->netdev_ops;
1503         struct tc_taprio_qopt_offload *offload;
1504         struct tc_taprio_caps caps;
1505         int tc, err = 0;
1506
1507         if (!ops->ndo_setup_tc) {
1508                 NL_SET_ERR_MSG(extack,
1509                                "Device does not support taprio offload");
1510                 return -EOPNOTSUPP;
1511         }
1512
1513         qdisc_offload_query_caps(dev, TC_SETUP_QDISC_TAPRIO,
1514                                  &caps, sizeof(caps));
1515
1516         if (!caps.supports_queue_max_sdu) {
1517                 for (tc = 0; tc < TC_MAX_QUEUE; tc++) {
1518                         if (q->max_sdu[tc]) {
1519                                 NL_SET_ERR_MSG_MOD(extack,
1520                                                    "Device does not handle queueMaxSDU");
1521                                 return -EOPNOTSUPP;
1522                         }
1523                 }
1524         }
1525
1526         offload = taprio_offload_alloc(sched->num_entries);
1527         if (!offload) {
1528                 NL_SET_ERR_MSG(extack,
1529                                "Not enough memory for enabling offload mode");
1530                 return -ENOMEM;
1531         }
1532         offload->cmd = TAPRIO_CMD_REPLACE;
1533         offload->extack = extack;
1534         mqprio_qopt_reconstruct(dev, &offload->mqprio.qopt);
1535         offload->mqprio.extack = extack;
1536         taprio_sched_to_offload(dev, sched, offload, &caps);
1537         mqprio_fp_to_offload(q->fp, &offload->mqprio);
1538
1539         for (tc = 0; tc < TC_MAX_QUEUE; tc++)
1540                 offload->max_sdu[tc] = q->max_sdu[tc];
1541
1542         err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1543         if (err < 0) {
1544                 NL_SET_ERR_MSG_WEAK(extack,
1545                                     "Device failed to setup taprio offload");
1546                 goto done;
1547         }
1548
1549         q->offloaded = true;
1550
1551 done:
1552         /* The offload structure may linger around via a reference taken by the
1553          * device driver, so clear up the netlink extack pointer so that the
1554          * driver isn't tempted to dereference data which stopped being valid
1555          */
1556         offload->extack = NULL;
1557         offload->mqprio.extack = NULL;
1558         taprio_offload_free(offload);
1559
1560         return err;
1561 }
1562
1563 static int taprio_disable_offload(struct net_device *dev,
1564                                   struct taprio_sched *q,
1565                                   struct netlink_ext_ack *extack)
1566 {
1567         const struct net_device_ops *ops = dev->netdev_ops;
1568         struct tc_taprio_qopt_offload *offload;
1569         int err;
1570
1571         if (!q->offloaded)
1572                 return 0;
1573
1574         offload = taprio_offload_alloc(0);
1575         if (!offload) {
1576                 NL_SET_ERR_MSG(extack,
1577                                "Not enough memory to disable offload mode");
1578                 return -ENOMEM;
1579         }
1580         offload->cmd = TAPRIO_CMD_DESTROY;
1581
1582         err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1583         if (err < 0) {
1584                 NL_SET_ERR_MSG(extack,
1585                                "Device failed to disable offload");
1586                 goto out;
1587         }
1588
1589         q->offloaded = false;
1590
1591 out:
1592         taprio_offload_free(offload);
1593
1594         return err;
1595 }
1596
1597 /* If full offload is enabled, the only possible clockid is the net device's
1598  * PHC. For that reason, specifying a clockid through netlink is incorrect.
1599  * For txtime-assist, it is implicitly assumed that the device's PHC is kept
1600  * in sync with the specified clockid via a user space daemon such as phc2sys.
1601  * For both software taprio and txtime-assist, the clockid is used for the
1602  * hrtimer that advances the schedule and hence mandatory.
1603  */
1604 static int taprio_parse_clockid(struct Qdisc *sch, struct nlattr **tb,
1605                                 struct netlink_ext_ack *extack)
1606 {
1607         struct taprio_sched *q = qdisc_priv(sch);
1608         struct net_device *dev = qdisc_dev(sch);
1609         int err = -EINVAL;
1610
1611         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1612                 const struct ethtool_ops *ops = dev->ethtool_ops;
1613                 struct kernel_ethtool_ts_info info = {
1614                         .cmd = ETHTOOL_GET_TS_INFO,
1615                         .phc_index = -1,
1616                 };
1617
1618                 if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1619                         NL_SET_ERR_MSG(extack,
1620                                        "The 'clockid' cannot be specified for full offload");
1621                         goto out;
1622                 }
1623
1624                 if (ops && ops->get_ts_info)
1625                         err = ops->get_ts_info(dev, &info);
1626
1627                 if (err || info.phc_index < 0) {
1628                         NL_SET_ERR_MSG(extack,
1629                                        "Device does not have a PTP clock");
1630                         err = -ENOTSUPP;
1631                         goto out;
1632                 }
1633         } else if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1634                 int clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
1635                 enum tk_offsets tk_offset;
1636
1637                 /* We only support static clockids and we don't allow
1638                  * for it to be modified after the first init.
1639                  */
1640                 if (clockid < 0 ||
1641                     (q->clockid != -1 && q->clockid != clockid)) {
1642                         NL_SET_ERR_MSG(extack,
1643                                        "Changing the 'clockid' of a running schedule is not supported");
1644                         err = -ENOTSUPP;
1645                         goto out;
1646                 }
1647
1648                 switch (clockid) {
1649                 case CLOCK_REALTIME:
1650                         tk_offset = TK_OFFS_REAL;
1651                         break;
1652                 case CLOCK_MONOTONIC:
1653                         tk_offset = TK_OFFS_MAX;
1654                         break;
1655                 case CLOCK_BOOTTIME:
1656                         tk_offset = TK_OFFS_BOOT;
1657                         break;
1658                 case CLOCK_TAI:
1659                         tk_offset = TK_OFFS_TAI;
1660                         break;
1661                 default:
1662                         NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
1663                         err = -EINVAL;
1664                         goto out;
1665                 }
1666                 /* This pairs with READ_ONCE() in taprio_mono_to_any */
1667                 WRITE_ONCE(q->tk_offset, tk_offset);
1668
1669                 q->clockid = clockid;
1670         } else {
1671                 NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
1672                 goto out;
1673         }
1674
1675         /* Everything went ok, return success. */
1676         err = 0;
1677
1678 out:
1679         return err;
1680 }
1681
1682 static int taprio_parse_tc_entry(struct Qdisc *sch,
1683                                  struct nlattr *opt,
1684                                  u32 max_sdu[TC_QOPT_MAX_QUEUE],
1685                                  u32 fp[TC_QOPT_MAX_QUEUE],
1686                                  unsigned long *seen_tcs,
1687                                  struct netlink_ext_ack *extack)
1688 {
1689         struct nlattr *tb[TCA_TAPRIO_TC_ENTRY_MAX + 1] = { };
1690         struct net_device *dev = qdisc_dev(sch);
1691         int err, tc;
1692         u32 val;
1693
1694         err = nla_parse_nested(tb, TCA_TAPRIO_TC_ENTRY_MAX, opt,
1695                                taprio_tc_policy, extack);
1696         if (err < 0)
1697                 return err;
1698
1699         if (!tb[TCA_TAPRIO_TC_ENTRY_INDEX]) {
1700                 NL_SET_ERR_MSG_MOD(extack, "TC entry index missing");
1701                 return -EINVAL;
1702         }
1703
1704         tc = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_INDEX]);
1705         if (tc >= TC_QOPT_MAX_QUEUE) {
1706                 NL_SET_ERR_MSG_MOD(extack, "TC entry index out of range");
1707                 return -ERANGE;
1708         }
1709
1710         if (*seen_tcs & BIT(tc)) {
1711                 NL_SET_ERR_MSG_MOD(extack, "Duplicate TC entry");
1712                 return -EINVAL;
1713         }
1714
1715         *seen_tcs |= BIT(tc);
1716
1717         if (tb[TCA_TAPRIO_TC_ENTRY_MAX_SDU]) {
1718                 val = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_MAX_SDU]);
1719                 if (val > dev->max_mtu) {
1720                         NL_SET_ERR_MSG_MOD(extack, "TC max SDU exceeds device max MTU");
1721                         return -ERANGE;
1722                 }
1723
1724                 max_sdu[tc] = val;
1725         }
1726
1727         if (tb[TCA_TAPRIO_TC_ENTRY_FP])
1728                 fp[tc] = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_FP]);
1729
1730         return 0;
1731 }
1732
1733 static int taprio_parse_tc_entries(struct Qdisc *sch,
1734                                    struct nlattr *opt,
1735                                    struct netlink_ext_ack *extack)
1736 {
1737         struct taprio_sched *q = qdisc_priv(sch);
1738         struct net_device *dev = qdisc_dev(sch);
1739         u32 max_sdu[TC_QOPT_MAX_QUEUE];
1740         bool have_preemption = false;
1741         unsigned long seen_tcs = 0;
1742         u32 fp[TC_QOPT_MAX_QUEUE];
1743         struct nlattr *n;
1744         int tc, rem;
1745         int err = 0;
1746
1747         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
1748                 max_sdu[tc] = q->max_sdu[tc];
1749                 fp[tc] = q->fp[tc];
1750         }
1751
1752         nla_for_each_nested_type(n, TCA_TAPRIO_ATTR_TC_ENTRY, opt, rem) {
1753                 err = taprio_parse_tc_entry(sch, n, max_sdu, fp, &seen_tcs,
1754                                             extack);
1755                 if (err)
1756                         return err;
1757         }
1758
1759         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
1760                 q->max_sdu[tc] = max_sdu[tc];
1761                 q->fp[tc] = fp[tc];
1762                 if (fp[tc] != TC_FP_EXPRESS)
1763                         have_preemption = true;
1764         }
1765
1766         if (have_preemption) {
1767                 if (!FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1768                         NL_SET_ERR_MSG(extack,
1769                                        "Preemption only supported with full offload");
1770                         return -EOPNOTSUPP;
1771                 }
1772
1773                 if (!ethtool_dev_mm_supported(dev)) {
1774                         NL_SET_ERR_MSG(extack,
1775                                        "Device does not support preemption");
1776                         return -EOPNOTSUPP;
1777                 }
1778         }
1779
1780         return err;
1781 }
1782
1783 static int taprio_mqprio_cmp(const struct net_device *dev,
1784                              const struct tc_mqprio_qopt *mqprio)
1785 {
1786         int i;
1787
1788         if (!mqprio || mqprio->num_tc != dev->num_tc)
1789                 return -1;
1790
1791         for (i = 0; i < mqprio->num_tc; i++)
1792                 if (dev->tc_to_txq[i].count != mqprio->count[i] ||
1793                     dev->tc_to_txq[i].offset != mqprio->offset[i])
1794                         return -1;
1795
1796         for (i = 0; i <= TC_BITMASK; i++)
1797                 if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
1798                         return -1;
1799
1800         return 0;
1801 }
1802
1803 static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
1804                          struct netlink_ext_ack *extack)
1805 {
1806         struct qdisc_size_table *stab = rtnl_dereference(sch->stab);
1807         struct nlattr *tb[TCA_TAPRIO_ATTR_MAX + 1] = { };
1808         struct sched_gate_list *oper, *admin, *new_admin;
1809         struct taprio_sched *q = qdisc_priv(sch);
1810         struct net_device *dev = qdisc_dev(sch);
1811         struct tc_mqprio_qopt *mqprio = NULL;
1812         unsigned long flags;
1813         u32 taprio_flags;
1814         ktime_t start;
1815         int i, err;
1816
1817         err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_ATTR_MAX, opt,
1818                                           taprio_policy, extack);
1819         if (err < 0)
1820                 return err;
1821
1822         if (tb[TCA_TAPRIO_ATTR_PRIOMAP])
1823                 mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]);
1824
1825         /* The semantics of the 'flags' argument in relation to 'change()'
1826          * requests, are interpreted following two rules (which are applied in
1827          * this order): (1) an omitted 'flags' argument is interpreted as
1828          * zero; (2) the 'flags' of a "running" taprio instance cannot be
1829          * changed.
1830          */
1831         taprio_flags = tb[TCA_TAPRIO_ATTR_FLAGS] ? nla_get_u32(tb[TCA_TAPRIO_ATTR_FLAGS]) : 0;
1832
1833         /* txtime-assist and full offload are mutually exclusive */
1834         if ((taprio_flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) &&
1835             (taprio_flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)) {
1836                 NL_SET_ERR_MSG_ATTR(extack, tb[TCA_TAPRIO_ATTR_FLAGS],
1837                                     "TXTIME_ASSIST and FULL_OFFLOAD are mutually exclusive");
1838                 return -EINVAL;
1839         }
1840
1841         if (q->flags != TAPRIO_FLAGS_INVALID && q->flags != taprio_flags) {
1842                 NL_SET_ERR_MSG_MOD(extack,
1843                                    "Changing 'flags' of a running schedule is not supported");
1844                 return -EOPNOTSUPP;
1845         }
1846         q->flags = taprio_flags;
1847
1848         /* Needed for length_to_duration() during netlink attribute parsing */
1849         taprio_set_picos_per_byte(dev, q);
1850
1851         err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags);
1852         if (err < 0)
1853                 return err;
1854
1855         err = taprio_parse_tc_entries(sch, opt, extack);
1856         if (err)
1857                 return err;
1858
1859         new_admin = kzalloc(sizeof(*new_admin), GFP_KERNEL);
1860         if (!new_admin) {
1861                 NL_SET_ERR_MSG(extack, "Not enough memory for a new schedule");
1862                 return -ENOMEM;
1863         }
1864         INIT_LIST_HEAD(&new_admin->entries);
1865
1866         oper = rtnl_dereference(q->oper_sched);
1867         admin = rtnl_dereference(q->admin_sched);
1868
1869         /* no changes - no new mqprio settings */
1870         if (!taprio_mqprio_cmp(dev, mqprio))
1871                 mqprio = NULL;
1872
1873         if (mqprio && (oper || admin)) {
1874                 NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
1875                 err = -ENOTSUPP;
1876                 goto free_sched;
1877         }
1878
1879         if (mqprio) {
1880                 err = netdev_set_num_tc(dev, mqprio->num_tc);
1881                 if (err)
1882                         goto free_sched;
1883                 for (i = 0; i < mqprio->num_tc; i++) {
1884                         netdev_set_tc_queue(dev, i,
1885                                             mqprio->count[i],
1886                                             mqprio->offset[i]);
1887                         q->cur_txq[i] = mqprio->offset[i];
1888                 }
1889
1890                 /* Always use supplied priority mappings */
1891                 for (i = 0; i <= TC_BITMASK; i++)
1892                         netdev_set_prio_tc_map(dev, i,
1893                                                mqprio->prio_tc_map[i]);
1894         }
1895
1896         err = parse_taprio_schedule(q, tb, new_admin, extack);
1897         if (err < 0)
1898                 goto free_sched;
1899
1900         if (new_admin->num_entries == 0) {
1901                 NL_SET_ERR_MSG(extack, "There should be at least one entry in the schedule");
1902                 err = -EINVAL;
1903                 goto free_sched;
1904         }
1905
1906         err = taprio_parse_clockid(sch, tb, extack);
1907         if (err < 0)
1908                 goto free_sched;
1909
1910         taprio_update_queue_max_sdu(q, new_admin, stab);
1911
1912         if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1913                 err = taprio_enable_offload(dev, q, new_admin, extack);
1914         else
1915                 err = taprio_disable_offload(dev, q, extack);
1916         if (err)
1917                 goto free_sched;
1918
1919         /* Protects against enqueue()/dequeue() */
1920         spin_lock_bh(qdisc_lock(sch));
1921
1922         if (tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]) {
1923                 if (!TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1924                         NL_SET_ERR_MSG_MOD(extack, "txtime-delay can only be set when txtime-assist mode is enabled");
1925                         err = -EINVAL;
1926                         goto unlock;
1927                 }
1928
1929                 q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
1930         }
1931
1932         if (!TXTIME_ASSIST_IS_ENABLED(q->flags) &&
1933             !FULL_OFFLOAD_IS_ENABLED(q->flags) &&
1934             !hrtimer_active(&q->advance_timer)) {
1935                 hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
1936                 q->advance_timer.function = advance_sched;
1937         }
1938
1939         err = taprio_get_start_time(sch, new_admin, &start);
1940         if (err < 0) {
1941                 NL_SET_ERR_MSG(extack, "Internal error: failed get start time");
1942                 goto unlock;
1943         }
1944
1945         setup_txtime(q, new_admin, start);
1946
1947         if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1948                 if (!oper) {
1949                         rcu_assign_pointer(q->oper_sched, new_admin);
1950                         err = 0;
1951                         new_admin = NULL;
1952                         goto unlock;
1953                 }
1954
1955                 /* Not going to race against advance_sched(), but still */
1956                 admin = rcu_replace_pointer(q->admin_sched, new_admin,
1957                                             lockdep_rtnl_is_held());
1958                 if (admin)
1959                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1960         } else {
1961                 setup_first_end_time(q, new_admin, start);
1962
1963                 /* Protects against advance_sched() */
1964                 spin_lock_irqsave(&q->current_entry_lock, flags);
1965
1966                 taprio_start_sched(sch, start, new_admin);
1967
1968                 rcu_assign_pointer(q->admin_sched, new_admin);
1969                 if (admin)
1970                         call_rcu(&admin->rcu, taprio_free_sched_cb);
1971
1972                 spin_unlock_irqrestore(&q->current_entry_lock, flags);
1973
1974                 if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1975                         taprio_offload_config_changed(q);
1976         }
1977
1978         new_admin = NULL;
1979         err = 0;
1980
1981         if (!stab)
1982                 NL_SET_ERR_MSG_MOD(extack,
1983                                    "Size table not specified, frame length estimations may be inaccurate");
1984
1985 unlock:
1986         spin_unlock_bh(qdisc_lock(sch));
1987
1988 free_sched:
1989         if (new_admin)
1990                 call_rcu(&new_admin->rcu, taprio_free_sched_cb);
1991
1992         return err;
1993 }
1994
1995 static void taprio_reset(struct Qdisc *sch)
1996 {
1997         struct taprio_sched *q = qdisc_priv(sch);
1998         struct net_device *dev = qdisc_dev(sch);
1999         int i;
2000
2001         hrtimer_cancel(&q->advance_timer);
2002
2003         if (q->qdiscs) {
2004                 for (i = 0; i < dev->num_tx_queues; i++)
2005                         if (q->qdiscs[i])
2006                                 qdisc_reset(q->qdiscs[i]);
2007         }
2008 }
2009
2010 static void taprio_destroy(struct Qdisc *sch)
2011 {
2012         struct taprio_sched *q = qdisc_priv(sch);
2013         struct net_device *dev = qdisc_dev(sch);
2014         struct sched_gate_list *oper, *admin;
2015         unsigned int i;
2016
2017         list_del(&q->taprio_list);
2018
2019         /* Note that taprio_reset() might not be called if an error
2020          * happens in qdisc_create(), after taprio_init() has been called.
2021          */
2022         hrtimer_cancel(&q->advance_timer);
2023         qdisc_synchronize(sch);
2024
2025         taprio_disable_offload(dev, q, NULL);
2026
2027         if (q->qdiscs) {
2028                 for (i = 0; i < dev->num_tx_queues; i++)
2029                         qdisc_put(q->qdiscs[i]);
2030
2031                 kfree(q->qdiscs);
2032         }
2033         q->qdiscs = NULL;
2034
2035         netdev_reset_tc(dev);
2036
2037         oper = rtnl_dereference(q->oper_sched);
2038         admin = rtnl_dereference(q->admin_sched);
2039
2040         if (oper)
2041                 call_rcu(&oper->rcu, taprio_free_sched_cb);
2042
2043         if (admin)
2044                 call_rcu(&admin->rcu, taprio_free_sched_cb);
2045
2046         taprio_cleanup_broken_mqprio(q);
2047 }
2048
2049 static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
2050                        struct netlink_ext_ack *extack)
2051 {
2052         struct taprio_sched *q = qdisc_priv(sch);
2053         struct net_device *dev = qdisc_dev(sch);
2054         int i, tc;
2055
2056         spin_lock_init(&q->current_entry_lock);
2057
2058         hrtimer_init(&q->advance_timer, CLOCK_TAI, HRTIMER_MODE_ABS);
2059         q->advance_timer.function = advance_sched;
2060
2061         q->root = sch;
2062
2063         /* We only support static clockids. Use an invalid value as default
2064          * and get the valid one on taprio_change().
2065          */
2066         q->clockid = -1;
2067         q->flags = TAPRIO_FLAGS_INVALID;
2068
2069         list_add(&q->taprio_list, &taprio_list);
2070
2071         if (sch->parent != TC_H_ROOT) {
2072                 NL_SET_ERR_MSG_MOD(extack, "Can only be attached as root qdisc");
2073                 return -EOPNOTSUPP;
2074         }
2075
2076         if (!netif_is_multiqueue(dev)) {
2077                 NL_SET_ERR_MSG_MOD(extack, "Multi-queue device is required");
2078                 return -EOPNOTSUPP;
2079         }
2080
2081         q->qdiscs = kcalloc(dev->num_tx_queues, sizeof(q->qdiscs[0]),
2082                             GFP_KERNEL);
2083         if (!q->qdiscs)
2084                 return -ENOMEM;
2085
2086         if (!opt)
2087                 return -EINVAL;
2088
2089         for (i = 0; i < dev->num_tx_queues; i++) {
2090                 struct netdev_queue *dev_queue;
2091                 struct Qdisc *qdisc;
2092
2093                 dev_queue = netdev_get_tx_queue(dev, i);
2094                 qdisc = qdisc_create_dflt(dev_queue,
2095                                           &pfifo_qdisc_ops,
2096                                           TC_H_MAKE(TC_H_MAJ(sch->handle),
2097                                                     TC_H_MIN(i + 1)),
2098                                           extack);
2099                 if (!qdisc)
2100                         return -ENOMEM;
2101
2102                 if (i < dev->real_num_tx_queues)
2103                         qdisc_hash_add(qdisc, false);
2104
2105                 q->qdiscs[i] = qdisc;
2106         }
2107
2108         for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
2109                 q->fp[tc] = TC_FP_EXPRESS;
2110
2111         taprio_detect_broken_mqprio(q);
2112
2113         return taprio_change(sch, opt, extack);
2114 }
2115
2116 static void taprio_attach(struct Qdisc *sch)
2117 {
2118         struct taprio_sched *q = qdisc_priv(sch);
2119         struct net_device *dev = qdisc_dev(sch);
2120         unsigned int ntx;
2121
2122         /* Attach underlying qdisc */
2123         for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
2124                 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
2125                 struct Qdisc *old, *dev_queue_qdisc;
2126
2127                 if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
2128                         struct Qdisc *qdisc = q->qdiscs[ntx];
2129
2130                         /* In offload mode, the root taprio qdisc is bypassed
2131                          * and the netdev TX queues see the children directly
2132                          */
2133                         qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
2134                         dev_queue_qdisc = qdisc;
2135                 } else {
2136                         /* In software mode, attach the root taprio qdisc
2137                          * to all netdev TX queues, so that dev_qdisc_enqueue()
2138                          * goes through taprio_enqueue().
2139                          */
2140                         dev_queue_qdisc = sch;
2141                 }
2142                 old = dev_graft_qdisc(dev_queue, dev_queue_qdisc);
2143                 /* The qdisc's refcount requires to be elevated once
2144                  * for each netdev TX queue it is grafted onto
2145                  */
2146                 qdisc_refcount_inc(dev_queue_qdisc);
2147                 if (old)
2148                         qdisc_put(old);
2149         }
2150 }
2151
2152 static struct netdev_queue *taprio_queue_get(struct Qdisc *sch,
2153                                              unsigned long cl)
2154 {
2155         struct net_device *dev = qdisc_dev(sch);
2156         unsigned long ntx = cl - 1;
2157
2158         if (ntx >= dev->num_tx_queues)
2159                 return NULL;
2160
2161         return netdev_get_tx_queue(dev, ntx);
2162 }
2163
2164 static int taprio_graft(struct Qdisc *sch, unsigned long cl,
2165                         struct Qdisc *new, struct Qdisc **old,
2166                         struct netlink_ext_ack *extack)
2167 {
2168         struct taprio_sched *q = qdisc_priv(sch);
2169         struct net_device *dev = qdisc_dev(sch);
2170         struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
2171
2172         if (!dev_queue)
2173                 return -EINVAL;
2174
2175         if (dev->flags & IFF_UP)
2176                 dev_deactivate(dev);
2177
2178         /* In offload mode, the child Qdisc is directly attached to the netdev
2179          * TX queue, and thus, we need to keep its refcount elevated in order
2180          * to counteract qdisc_graft()'s call to qdisc_put() once per TX queue.
2181          * However, save the reference to the new qdisc in the private array in
2182          * both software and offload cases, to have an up-to-date reference to
2183          * our children.
2184          */
2185         *old = q->qdiscs[cl - 1];
2186         if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
2187                 WARN_ON_ONCE(dev_graft_qdisc(dev_queue, new) != *old);
2188                 if (new)
2189                         qdisc_refcount_inc(new);
2190                 if (*old)
2191                         qdisc_put(*old);
2192         }
2193
2194         q->qdiscs[cl - 1] = new;
2195         if (new)
2196                 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
2197
2198         if (dev->flags & IFF_UP)
2199                 dev_activate(dev);
2200
2201         return 0;
2202 }
2203
2204 static int dump_entry(struct sk_buff *msg,
2205                       const struct sched_entry *entry)
2206 {
2207         struct nlattr *item;
2208
2209         item = nla_nest_start_noflag(msg, TCA_TAPRIO_SCHED_ENTRY);
2210         if (!item)
2211                 return -ENOSPC;
2212
2213         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INDEX, entry->index))
2214                 goto nla_put_failure;
2215
2216         if (nla_put_u8(msg, TCA_TAPRIO_SCHED_ENTRY_CMD, entry->command))
2217                 goto nla_put_failure;
2218
2219         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_GATE_MASK,
2220                         entry->gate_mask))
2221                 goto nla_put_failure;
2222
2223         if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INTERVAL,
2224                         entry->interval))
2225                 goto nla_put_failure;
2226
2227         return nla_nest_end(msg, item);
2228
2229 nla_put_failure:
2230         nla_nest_cancel(msg, item);
2231         return -1;
2232 }
2233
2234 static int dump_schedule(struct sk_buff *msg,
2235                          const struct sched_gate_list *root)
2236 {
2237         struct nlattr *entry_list;
2238         struct sched_entry *entry;
2239
2240         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_BASE_TIME,
2241                         root->base_time, TCA_TAPRIO_PAD))
2242                 return -1;
2243
2244         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME,
2245                         root->cycle_time, TCA_TAPRIO_PAD))
2246                 return -1;
2247
2248         if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION,
2249                         root->cycle_time_extension, TCA_TAPRIO_PAD))
2250                 return -1;
2251
2252         entry_list = nla_nest_start_noflag(msg,
2253                                            TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST);
2254         if (!entry_list)
2255                 goto error_nest;
2256
2257         list_for_each_entry(entry, &root->entries, list) {
2258                 if (dump_entry(msg, entry) < 0)
2259                         goto error_nest;
2260         }
2261
2262         nla_nest_end(msg, entry_list);
2263         return 0;
2264
2265 error_nest:
2266         nla_nest_cancel(msg, entry_list);
2267         return -1;
2268 }
2269
2270 static int taprio_dump_tc_entries(struct sk_buff *skb,
2271                                   struct taprio_sched *q,
2272                                   struct sched_gate_list *sched)
2273 {
2274         struct nlattr *n;
2275         int tc;
2276
2277         for (tc = 0; tc < TC_MAX_QUEUE; tc++) {
2278                 n = nla_nest_start(skb, TCA_TAPRIO_ATTR_TC_ENTRY);
2279                 if (!n)
2280                         return -EMSGSIZE;
2281
2282                 if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_INDEX, tc))
2283                         goto nla_put_failure;
2284
2285                 if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_MAX_SDU,
2286                                 sched->max_sdu[tc]))
2287                         goto nla_put_failure;
2288
2289                 if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_FP, q->fp[tc]))
2290                         goto nla_put_failure;
2291
2292                 nla_nest_end(skb, n);
2293         }
2294
2295         return 0;
2296
2297 nla_put_failure:
2298         nla_nest_cancel(skb, n);
2299         return -EMSGSIZE;
2300 }
2301
2302 static int taprio_put_stat(struct sk_buff *skb, u64 val, u16 attrtype)
2303 {
2304         if (val == TAPRIO_STAT_NOT_SET)
2305                 return 0;
2306         if (nla_put_u64_64bit(skb, attrtype, val, TCA_TAPRIO_OFFLOAD_STATS_PAD))
2307                 return -EMSGSIZE;
2308         return 0;
2309 }
2310
2311 static int taprio_dump_xstats(struct Qdisc *sch, struct gnet_dump *d,
2312                               struct tc_taprio_qopt_offload *offload,
2313                               struct tc_taprio_qopt_stats *stats)
2314 {
2315         struct net_device *dev = qdisc_dev(sch);
2316         const struct net_device_ops *ops;
2317         struct sk_buff *skb = d->skb;
2318         struct nlattr *xstats;
2319         int err;
2320
2321         ops = qdisc_dev(sch)->netdev_ops;
2322
2323         /* FIXME I could use qdisc_offload_dump_helper(), but that messes
2324          * with sch->flags depending on whether the device reports taprio
2325          * stats, and I'm not sure whether that's a good idea, considering
2326          * that stats are optional to the offload itself
2327          */
2328         if (!ops->ndo_setup_tc)
2329                 return 0;
2330
2331         memset(stats, 0xff, sizeof(*stats));
2332
2333         err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
2334         if (err == -EOPNOTSUPP)
2335                 return 0;
2336         if (err)
2337                 return err;
2338
2339         xstats = nla_nest_start(skb, TCA_STATS_APP);
2340         if (!xstats)
2341                 goto err;
2342
2343         if (taprio_put_stat(skb, stats->window_drops,
2344                             TCA_TAPRIO_OFFLOAD_STATS_WINDOW_DROPS) ||
2345             taprio_put_stat(skb, stats->tx_overruns,
2346                             TCA_TAPRIO_OFFLOAD_STATS_TX_OVERRUNS))
2347                 goto err_cancel;
2348
2349         nla_nest_end(skb, xstats);
2350
2351         return 0;
2352
2353 err_cancel:
2354         nla_nest_cancel(skb, xstats);
2355 err:
2356         return -EMSGSIZE;
2357 }
2358
2359 static int taprio_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
2360 {
2361         struct tc_taprio_qopt_offload offload = {
2362                 .cmd = TAPRIO_CMD_STATS,
2363         };
2364
2365         return taprio_dump_xstats(sch, d, &offload, &offload.stats);
2366 }
2367
2368 static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
2369 {
2370         struct taprio_sched *q = qdisc_priv(sch);
2371         struct net_device *dev = qdisc_dev(sch);
2372         struct sched_gate_list *oper, *admin;
2373         struct tc_mqprio_qopt opt = { 0 };
2374         struct nlattr *nest, *sched_nest;
2375
2376         oper = rtnl_dereference(q->oper_sched);
2377         admin = rtnl_dereference(q->admin_sched);
2378
2379         mqprio_qopt_reconstruct(dev, &opt);
2380
2381         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
2382         if (!nest)
2383                 goto start_error;
2384
2385         if (nla_put(skb, TCA_TAPRIO_ATTR_PRIOMAP, sizeof(opt), &opt))
2386                 goto options_error;
2387
2388         if (!FULL_OFFLOAD_IS_ENABLED(q->flags) &&
2389             nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
2390                 goto options_error;
2391
2392         if (q->flags && nla_put_u32(skb, TCA_TAPRIO_ATTR_FLAGS, q->flags))
2393                 goto options_error;
2394
2395         if (q->txtime_delay &&
2396             nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
2397                 goto options_error;
2398
2399         if (oper && taprio_dump_tc_entries(skb, q, oper))
2400                 goto options_error;
2401
2402         if (oper && dump_schedule(skb, oper))
2403                 goto options_error;
2404
2405         if (!admin)
2406                 goto done;
2407
2408         sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
2409         if (!sched_nest)
2410                 goto options_error;
2411
2412         if (dump_schedule(skb, admin))
2413                 goto admin_error;
2414
2415         nla_nest_end(skb, sched_nest);
2416
2417 done:
2418         return nla_nest_end(skb, nest);
2419
2420 admin_error:
2421         nla_nest_cancel(skb, sched_nest);
2422
2423 options_error:
2424         nla_nest_cancel(skb, nest);
2425
2426 start_error:
2427         return -ENOSPC;
2428 }
2429
2430 static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
2431 {
2432         struct taprio_sched *q = qdisc_priv(sch);
2433         struct net_device *dev = qdisc_dev(sch);
2434         unsigned int ntx = cl - 1;
2435
2436         if (ntx >= dev->num_tx_queues)
2437                 return NULL;
2438
2439         return q->qdiscs[ntx];
2440 }
2441
2442 static unsigned long taprio_find(struct Qdisc *sch, u32 classid)
2443 {
2444         unsigned int ntx = TC_H_MIN(classid);
2445
2446         if (!taprio_queue_get(sch, ntx))
2447                 return 0;
2448         return ntx;
2449 }
2450
2451 static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
2452                              struct sk_buff *skb, struct tcmsg *tcm)
2453 {
2454         struct Qdisc *child = taprio_leaf(sch, cl);
2455
2456         tcm->tcm_parent = TC_H_ROOT;
2457         tcm->tcm_handle |= TC_H_MIN(cl);
2458         tcm->tcm_info = child->handle;
2459
2460         return 0;
2461 }
2462
2463 static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
2464                                    struct gnet_dump *d)
2465         __releases(d->lock)
2466         __acquires(d->lock)
2467 {
2468         struct Qdisc *child = taprio_leaf(sch, cl);
2469         struct tc_taprio_qopt_offload offload = {
2470                 .cmd = TAPRIO_CMD_QUEUE_STATS,
2471                 .queue_stats = {
2472                         .queue = cl - 1,
2473                 },
2474         };
2475
2476         if (gnet_stats_copy_basic(d, NULL, &child->bstats, true) < 0 ||
2477             qdisc_qstats_copy(d, child) < 0)
2478                 return -1;
2479
2480         return taprio_dump_xstats(sch, d, &offload, &offload.queue_stats.stats);
2481 }
2482
2483 static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2484 {
2485         struct net_device *dev = qdisc_dev(sch);
2486         unsigned long ntx;
2487
2488         if (arg->stop)
2489                 return;
2490
2491         arg->count = arg->skip;
2492         for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
2493                 if (!tc_qdisc_stats_dump(sch, ntx + 1, arg))
2494                         break;
2495         }
2496 }
2497
2498 static struct netdev_queue *taprio_select_queue(struct Qdisc *sch,
2499                                                 struct tcmsg *tcm)
2500 {
2501         return taprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
2502 }
2503
2504 static const struct Qdisc_class_ops taprio_class_ops = {
2505         .graft          = taprio_graft,
2506         .leaf           = taprio_leaf,
2507         .find           = taprio_find,
2508         .walk           = taprio_walk,
2509         .dump           = taprio_dump_class,
2510         .dump_stats     = taprio_dump_class_stats,
2511         .select_queue   = taprio_select_queue,
2512 };
2513
2514 static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
2515         .cl_ops         = &taprio_class_ops,
2516         .id             = "taprio",
2517         .priv_size      = sizeof(struct taprio_sched),
2518         .init           = taprio_init,
2519         .change         = taprio_change,
2520         .destroy        = taprio_destroy,
2521         .reset          = taprio_reset,
2522         .attach         = taprio_attach,
2523         .peek           = taprio_peek,
2524         .dequeue        = taprio_dequeue,
2525         .enqueue        = taprio_enqueue,
2526         .dump           = taprio_dump,
2527         .dump_stats     = taprio_dump_stats,
2528         .owner          = THIS_MODULE,
2529 };
2530 MODULE_ALIAS_NET_SCH("taprio");
2531
2532 static struct notifier_block taprio_device_notifier = {
2533         .notifier_call = taprio_dev_notifier,
2534 };
2535
2536 static int __init taprio_module_init(void)
2537 {
2538         int err = register_netdevice_notifier(&taprio_device_notifier);
2539
2540         if (err)
2541                 return err;
2542
2543         return register_qdisc(&taprio_qdisc_ops);
2544 }
2545
2546 static void __exit taprio_module_exit(void)
2547 {
2548         unregister_qdisc(&taprio_qdisc_ops);
2549         unregister_netdevice_notifier(&taprio_device_notifier);
2550 }
2551
2552 module_init(taprio_module_init);
2553 module_exit(taprio_module_exit);
2554 MODULE_LICENSE("GPL");
2555 MODULE_DESCRIPTION("Time Aware Priority qdisc");