linux/net/sched/sch_taprio.c
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   1// SPDX-License-Identifier: GPL-2.0
   2
   3/* net/sched/sch_taprio.c        Time Aware Priority Scheduler
   4 *
   5 * Authors:     Vinicius Costa Gomes <vinicius.gomes@intel.com>
   6 *
   7 */
   8
   9#include <linux/ethtool.h>
  10#include <linux/types.h>
  11#include <linux/slab.h>
  12#include <linux/kernel.h>
  13#include <linux/string.h>
  14#include <linux/list.h>
  15#include <linux/errno.h>
  16#include <linux/skbuff.h>
  17#include <linux/math64.h>
  18#include <linux/module.h>
  19#include <linux/spinlock.h>
  20#include <linux/rcupdate.h>
  21#include <net/netlink.h>
  22#include <net/pkt_sched.h>
  23#include <net/pkt_cls.h>
  24#include <net/sch_generic.h>
  25#include <net/sock.h>
  26#include <net/tcp.h>
  27
  28static LIST_HEAD(taprio_list);
  29static DEFINE_SPINLOCK(taprio_list_lock);
  30
  31#define TAPRIO_ALL_GATES_OPEN -1
  32
  33#define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST)
  34#define FULL_OFFLOAD_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
  35#define TAPRIO_FLAGS_INVALID U32_MAX
  36
  37struct sched_entry {
  38        struct list_head list;
  39
  40        /* The instant that this entry "closes" and the next one
  41         * should open, the qdisc will make some effort so that no
  42         * packet leaves after this time.
  43         */
  44        ktime_t close_time;
  45        ktime_t next_txtime;
  46        atomic_t budget;
  47        int index;
  48        u32 gate_mask;
  49        u32 interval;
  50        u8 command;
  51};
  52
  53struct sched_gate_list {
  54        struct rcu_head rcu;
  55        struct list_head entries;
  56        size_t num_entries;
  57        ktime_t cycle_close_time;
  58        s64 cycle_time;
  59        s64 cycle_time_extension;
  60        s64 base_time;
  61};
  62
  63struct taprio_sched {
  64        struct Qdisc **qdiscs;
  65        struct Qdisc *root;
  66        u32 flags;
  67        enum tk_offsets tk_offset;
  68        int clockid;
  69        atomic64_t picos_per_byte; /* Using picoseconds because for 10Gbps+
  70                                    * speeds it's sub-nanoseconds per byte
  71                                    */
  72
  73        /* Protects the update side of the RCU protected current_entry */
  74        spinlock_t current_entry_lock;
  75        struct sched_entry __rcu *current_entry;
  76        struct sched_gate_list __rcu *oper_sched;
  77        struct sched_gate_list __rcu *admin_sched;
  78        struct hrtimer advance_timer;
  79        struct list_head taprio_list;
  80        struct sk_buff *(*dequeue)(struct Qdisc *sch);
  81        struct sk_buff *(*peek)(struct Qdisc *sch);
  82        u32 txtime_delay;
  83};
  84
  85struct __tc_taprio_qopt_offload {
  86        refcount_t users;
  87        struct tc_taprio_qopt_offload offload;
  88};
  89
  90static ktime_t sched_base_time(const struct sched_gate_list *sched)
  91{
  92        if (!sched)
  93                return KTIME_MAX;
  94
  95        return ns_to_ktime(sched->base_time);
  96}
  97
  98static ktime_t taprio_get_time(struct taprio_sched *q)
  99{
 100        ktime_t mono = ktime_get();
 101
 102        switch (q->tk_offset) {
 103        case TK_OFFS_MAX:
 104                return mono;
 105        default:
 106                return ktime_mono_to_any(mono, q->tk_offset);
 107        }
 108
 109        return KTIME_MAX;
 110}
 111
 112static void taprio_free_sched_cb(struct rcu_head *head)
 113{
 114        struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
 115        struct sched_entry *entry, *n;
 116
 117        list_for_each_entry_safe(entry, n, &sched->entries, list) {
 118                list_del(&entry->list);
 119                kfree(entry);
 120        }
 121
 122        kfree(sched);
 123}
 124
 125static void switch_schedules(struct taprio_sched *q,
 126                             struct sched_gate_list **admin,
 127                             struct sched_gate_list **oper)
 128{
 129        rcu_assign_pointer(q->oper_sched, *admin);
 130        rcu_assign_pointer(q->admin_sched, NULL);
 131
 132        if (*oper)
 133                call_rcu(&(*oper)->rcu, taprio_free_sched_cb);
 134
 135        *oper = *admin;
 136        *admin = NULL;
 137}
 138
 139/* Get how much time has been already elapsed in the current cycle. */
 140static s32 get_cycle_time_elapsed(struct sched_gate_list *sched, ktime_t time)
 141{
 142        ktime_t time_since_sched_start;
 143        s32 time_elapsed;
 144
 145        time_since_sched_start = ktime_sub(time, sched->base_time);
 146        div_s64_rem(time_since_sched_start, sched->cycle_time, &time_elapsed);
 147
 148        return time_elapsed;
 149}
 150
 151static ktime_t get_interval_end_time(struct sched_gate_list *sched,
 152                                     struct sched_gate_list *admin,
 153                                     struct sched_entry *entry,
 154                                     ktime_t intv_start)
 155{
 156        s32 cycle_elapsed = get_cycle_time_elapsed(sched, intv_start);
 157        ktime_t intv_end, cycle_ext_end, cycle_end;
 158
 159        cycle_end = ktime_add_ns(intv_start, sched->cycle_time - cycle_elapsed);
 160        intv_end = ktime_add_ns(intv_start, entry->interval);
 161        cycle_ext_end = ktime_add(cycle_end, sched->cycle_time_extension);
 162
 163        if (ktime_before(intv_end, cycle_end))
 164                return intv_end;
 165        else if (admin && admin != sched &&
 166                 ktime_after(admin->base_time, cycle_end) &&
 167                 ktime_before(admin->base_time, cycle_ext_end))
 168                return admin->base_time;
 169        else
 170                return cycle_end;
 171}
 172
 173static int length_to_duration(struct taprio_sched *q, int len)
 174{
 175        return div_u64(len * atomic64_read(&q->picos_per_byte), 1000);
 176}
 177
 178/* Returns the entry corresponding to next available interval. If
 179 * validate_interval is set, it only validates whether the timestamp occurs
 180 * when the gate corresponding to the skb's traffic class is open.
 181 */
 182static struct sched_entry *find_entry_to_transmit(struct sk_buff *skb,
 183                                                  struct Qdisc *sch,
 184                                                  struct sched_gate_list *sched,
 185                                                  struct sched_gate_list *admin,
 186                                                  ktime_t time,
 187                                                  ktime_t *interval_start,
 188                                                  ktime_t *interval_end,
 189                                                  bool validate_interval)
 190{
 191        ktime_t curr_intv_start, curr_intv_end, cycle_end, packet_transmit_time;
 192        ktime_t earliest_txtime = KTIME_MAX, txtime, cycle, transmit_end_time;
 193        struct sched_entry *entry = NULL, *entry_found = NULL;
 194        struct taprio_sched *q = qdisc_priv(sch);
 195        struct net_device *dev = qdisc_dev(sch);
 196        bool entry_available = false;
 197        s32 cycle_elapsed;
 198        int tc, n;
 199
 200        tc = netdev_get_prio_tc_map(dev, skb->priority);
 201        packet_transmit_time = length_to_duration(q, qdisc_pkt_len(skb));
 202
 203        *interval_start = 0;
 204        *interval_end = 0;
 205
 206        if (!sched)
 207                return NULL;
 208
 209        cycle = sched->cycle_time;
 210        cycle_elapsed = get_cycle_time_elapsed(sched, time);
 211        curr_intv_end = ktime_sub_ns(time, cycle_elapsed);
 212        cycle_end = ktime_add_ns(curr_intv_end, cycle);
 213
 214        list_for_each_entry(entry, &sched->entries, list) {
 215                curr_intv_start = curr_intv_end;
 216                curr_intv_end = get_interval_end_time(sched, admin, entry,
 217                                                      curr_intv_start);
 218
 219                if (ktime_after(curr_intv_start, cycle_end))
 220                        break;
 221
 222                if (!(entry->gate_mask & BIT(tc)) ||
 223                    packet_transmit_time > entry->interval)
 224                        continue;
 225
 226                txtime = entry->next_txtime;
 227
 228                if (ktime_before(txtime, time) || validate_interval) {
 229                        transmit_end_time = ktime_add_ns(time, packet_transmit_time);
 230                        if ((ktime_before(curr_intv_start, time) &&
 231                             ktime_before(transmit_end_time, curr_intv_end)) ||
 232                            (ktime_after(curr_intv_start, time) && !validate_interval)) {
 233                                entry_found = entry;
 234                                *interval_start = curr_intv_start;
 235                                *interval_end = curr_intv_end;
 236                                break;
 237                        } else if (!entry_available && !validate_interval) {
 238                                /* Here, we are just trying to find out the
 239                                 * first available interval in the next cycle.
 240                                 */
 241                                entry_available = true;
 242                                entry_found = entry;
 243                                *interval_start = ktime_add_ns(curr_intv_start, cycle);
 244                                *interval_end = ktime_add_ns(curr_intv_end, cycle);
 245                        }
 246                } else if (ktime_before(txtime, earliest_txtime) &&
 247                           !entry_available) {
 248                        earliest_txtime = txtime;
 249                        entry_found = entry;
 250                        n = div_s64(ktime_sub(txtime, curr_intv_start), cycle);
 251                        *interval_start = ktime_add(curr_intv_start, n * cycle);
 252                        *interval_end = ktime_add(curr_intv_end, n * cycle);
 253                }
 254        }
 255
 256        return entry_found;
 257}
 258
 259static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
 260{
 261        struct taprio_sched *q = qdisc_priv(sch);
 262        struct sched_gate_list *sched, *admin;
 263        ktime_t interval_start, interval_end;
 264        struct sched_entry *entry;
 265
 266        rcu_read_lock();
 267        sched = rcu_dereference(q->oper_sched);
 268        admin = rcu_dereference(q->admin_sched);
 269
 270        entry = find_entry_to_transmit(skb, sch, sched, admin, skb->tstamp,
 271                                       &interval_start, &interval_end, true);
 272        rcu_read_unlock();
 273
 274        return entry;
 275}
 276
 277static bool taprio_flags_valid(u32 flags)
 278{
 279        /* Make sure no other flag bits are set. */
 280        if (flags & ~(TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST |
 281                      TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD))
 282                return false;
 283        /* txtime-assist and full offload are mutually exclusive */
 284        if ((flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) &&
 285            (flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD))
 286                return false;
 287        return true;
 288}
 289
 290/* This returns the tstamp value set by TCP in terms of the set clock. */
 291static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
 292{
 293        unsigned int offset = skb_network_offset(skb);
 294        const struct ipv6hdr *ipv6h;
 295        const struct iphdr *iph;
 296        struct ipv6hdr _ipv6h;
 297
 298        ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
 299        if (!ipv6h)
 300                return 0;
 301
 302        if (ipv6h->version == 4) {
 303                iph = (struct iphdr *)ipv6h;
 304                offset += iph->ihl * 4;
 305
 306                /* special-case 6in4 tunnelling, as that is a common way to get
 307                 * v6 connectivity in the home
 308                 */
 309                if (iph->protocol == IPPROTO_IPV6) {
 310                        ipv6h = skb_header_pointer(skb, offset,
 311                                                   sizeof(_ipv6h), &_ipv6h);
 312
 313                        if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
 314                                return 0;
 315                } else if (iph->protocol != IPPROTO_TCP) {
 316                        return 0;
 317                }
 318        } else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
 319                return 0;
 320        }
 321
 322        return ktime_mono_to_any(skb->skb_mstamp_ns, q->tk_offset);
 323}
 324
 325/* There are a few scenarios where we will have to modify the txtime from
 326 * what is read from next_txtime in sched_entry. They are:
 327 * 1. If txtime is in the past,
 328 *    a. The gate for the traffic class is currently open and packet can be
 329 *       transmitted before it closes, schedule the packet right away.
 330 *    b. If the gate corresponding to the traffic class is going to open later
 331 *       in the cycle, set the txtime of packet to the interval start.
 332 * 2. If txtime is in the future, there are packets corresponding to the
 333 *    current traffic class waiting to be transmitted. So, the following
 334 *    possibilities exist:
 335 *    a. We can transmit the packet before the window containing the txtime
 336 *       closes.
 337 *    b. The window might close before the transmission can be completed
 338 *       successfully. So, schedule the packet in the next open window.
 339 */
 340static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 341{
 342        ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
 343        struct taprio_sched *q = qdisc_priv(sch);
 344        struct sched_gate_list *sched, *admin;
 345        ktime_t minimum_time, now, txtime;
 346        int len, packet_transmit_time;
 347        struct sched_entry *entry;
 348        bool sched_changed;
 349
 350        now = taprio_get_time(q);
 351        minimum_time = ktime_add_ns(now, q->txtime_delay);
 352
 353        tcp_tstamp = get_tcp_tstamp(q, skb);
 354        minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
 355
 356        rcu_read_lock();
 357        admin = rcu_dereference(q->admin_sched);
 358        sched = rcu_dereference(q->oper_sched);
 359        if (admin && ktime_after(minimum_time, admin->base_time))
 360                switch_schedules(q, &admin, &sched);
 361
 362        /* Until the schedule starts, all the queues are open */
 363        if (!sched || ktime_before(minimum_time, sched->base_time)) {
 364                txtime = minimum_time;
 365                goto done;
 366        }
 367
 368        len = qdisc_pkt_len(skb);
 369        packet_transmit_time = length_to_duration(q, len);
 370
 371        do {
 372                sched_changed = false;
 373
 374                entry = find_entry_to_transmit(skb, sch, sched, admin,
 375                                               minimum_time,
 376                                               &interval_start, &interval_end,
 377                                               false);
 378                if (!entry) {
 379                        txtime = 0;
 380                        goto done;
 381                }
 382
 383                txtime = entry->next_txtime;
 384                txtime = max_t(ktime_t, txtime, minimum_time);
 385                txtime = max_t(ktime_t, txtime, interval_start);
 386
 387                if (admin && admin != sched &&
 388                    ktime_after(txtime, admin->base_time)) {
 389                        sched = admin;
 390                        sched_changed = true;
 391                        continue;
 392                }
 393
 394                transmit_end_time = ktime_add(txtime, packet_transmit_time);
 395                minimum_time = transmit_end_time;
 396
 397                /* Update the txtime of current entry to the next time it's
 398                 * interval starts.
 399                 */
 400                if (ktime_after(transmit_end_time, interval_end))
 401                        entry->next_txtime = ktime_add(interval_start, sched->cycle_time);
 402        } while (sched_changed || ktime_after(transmit_end_time, interval_end));
 403
 404        entry->next_txtime = transmit_end_time;
 405
 406done:
 407        rcu_read_unlock();
 408        return txtime;
 409}
 410
 411static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch,
 412                              struct Qdisc *child, struct sk_buff **to_free)
 413{
 414        struct taprio_sched *q = qdisc_priv(sch);
 415
 416        if (skb->sk && sock_flag(skb->sk, SOCK_TXTIME)) {
 417                if (!is_valid_interval(skb, sch))
 418                        return qdisc_drop(skb, sch, to_free);
 419        } else if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 420                skb->tstamp = get_packet_txtime(skb, sch);
 421                if (!skb->tstamp)
 422                        return qdisc_drop(skb, sch, to_free);
 423        }
 424
 425        qdisc_qstats_backlog_inc(sch, skb);
 426        sch->q.qlen++;
 427
 428        return qdisc_enqueue(skb, child, to_free);
 429}
 430
 431static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 432                          struct sk_buff **to_free)
 433{
 434        struct taprio_sched *q = qdisc_priv(sch);
 435        struct Qdisc *child;
 436        int queue;
 437
 438        if (unlikely(FULL_OFFLOAD_IS_ENABLED(q->flags))) {
 439                WARN_ONCE(1, "Trying to enqueue skb into the root of a taprio qdisc configured with full offload\n");
 440                return qdisc_drop(skb, sch, to_free);
 441        }
 442
 443        queue = skb_get_queue_mapping(skb);
 444
 445        child = q->qdiscs[queue];
 446        if (unlikely(!child))
 447                return qdisc_drop(skb, sch, to_free);
 448
 449        /* Large packets might not be transmitted when the transmission duration
 450         * exceeds any configured interval. Therefore, segment the skb into
 451         * smaller chunks. Skip it for the full offload case, as the driver
 452         * and/or the hardware is expected to handle this.
 453         */
 454        if (skb_is_gso(skb) && !FULL_OFFLOAD_IS_ENABLED(q->flags)) {
 455                unsigned int slen = 0, numsegs = 0, len = qdisc_pkt_len(skb);
 456                netdev_features_t features = netif_skb_features(skb);
 457                struct sk_buff *segs, *nskb;
 458                int ret;
 459
 460                segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
 461                if (IS_ERR_OR_NULL(segs))
 462                        return qdisc_drop(skb, sch, to_free);
 463
 464                skb_list_walk_safe(segs, segs, nskb) {
 465                        skb_mark_not_on_list(segs);
 466                        qdisc_skb_cb(segs)->pkt_len = segs->len;
 467                        slen += segs->len;
 468
 469                        ret = taprio_enqueue_one(segs, sch, child, to_free);
 470                        if (ret != NET_XMIT_SUCCESS) {
 471                                if (net_xmit_drop_count(ret))
 472                                        qdisc_qstats_drop(sch);
 473                        } else {
 474                                numsegs++;
 475                        }
 476                }
 477
 478                if (numsegs > 1)
 479                        qdisc_tree_reduce_backlog(sch, 1 - numsegs, len - slen);
 480                consume_skb(skb);
 481
 482                return numsegs > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 483        }
 484
 485        return taprio_enqueue_one(skb, sch, child, to_free);
 486}
 487
 488static struct sk_buff *taprio_peek_soft(struct Qdisc *sch)
 489{
 490        struct taprio_sched *q = qdisc_priv(sch);
 491        struct net_device *dev = qdisc_dev(sch);
 492        struct sched_entry *entry;
 493        struct sk_buff *skb;
 494        u32 gate_mask;
 495        int i;
 496
 497        rcu_read_lock();
 498        entry = rcu_dereference(q->current_entry);
 499        gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 500        rcu_read_unlock();
 501
 502        if (!gate_mask)
 503                return NULL;
 504
 505        for (i = 0; i < dev->num_tx_queues; i++) {
 506                struct Qdisc *child = q->qdiscs[i];
 507                int prio;
 508                u8 tc;
 509
 510                if (unlikely(!child))
 511                        continue;
 512
 513                skb = child->ops->peek(child);
 514                if (!skb)
 515                        continue;
 516
 517                if (TXTIME_ASSIST_IS_ENABLED(q->flags))
 518                        return skb;
 519
 520                prio = skb->priority;
 521                tc = netdev_get_prio_tc_map(dev, prio);
 522
 523                if (!(gate_mask & BIT(tc)))
 524                        continue;
 525
 526                return skb;
 527        }
 528
 529        return NULL;
 530}
 531
 532static struct sk_buff *taprio_peek_offload(struct Qdisc *sch)
 533{
 534        WARN_ONCE(1, "Trying to peek into the root of a taprio qdisc configured with full offload\n");
 535
 536        return NULL;
 537}
 538
 539static struct sk_buff *taprio_peek(struct Qdisc *sch)
 540{
 541        struct taprio_sched *q = qdisc_priv(sch);
 542
 543        return q->peek(sch);
 544}
 545
 546static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry)
 547{
 548        atomic_set(&entry->budget,
 549                   div64_u64((u64)entry->interval * 1000,
 550                             atomic64_read(&q->picos_per_byte)));
 551}
 552
 553static struct sk_buff *taprio_dequeue_soft(struct Qdisc *sch)
 554{
 555        struct taprio_sched *q = qdisc_priv(sch);
 556        struct net_device *dev = qdisc_dev(sch);
 557        struct sk_buff *skb = NULL;
 558        struct sched_entry *entry;
 559        u32 gate_mask;
 560        int i;
 561
 562        rcu_read_lock();
 563        entry = rcu_dereference(q->current_entry);
 564        /* if there's no entry, it means that the schedule didn't
 565         * start yet, so force all gates to be open, this is in
 566         * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5
 567         * "AdminGateStates"
 568         */
 569        gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
 570
 571        if (!gate_mask)
 572                goto done;
 573
 574        for (i = 0; i < dev->num_tx_queues; i++) {
 575                struct Qdisc *child = q->qdiscs[i];
 576                ktime_t guard;
 577                int prio;
 578                int len;
 579                u8 tc;
 580
 581                if (unlikely(!child))
 582                        continue;
 583
 584                if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
 585                        skb = child->ops->dequeue(child);
 586                        if (!skb)
 587                                continue;
 588                        goto skb_found;
 589                }
 590
 591                skb = child->ops->peek(child);
 592                if (!skb)
 593                        continue;
 594
 595                prio = skb->priority;
 596                tc = netdev_get_prio_tc_map(dev, prio);
 597
 598                if (!(gate_mask & BIT(tc))) {
 599                        skb = NULL;
 600                        continue;
 601                }
 602
 603                len = qdisc_pkt_len(skb);
 604                guard = ktime_add_ns(taprio_get_time(q),
 605                                     length_to_duration(q, len));
 606
 607                /* In the case that there's no gate entry, there's no
 608                 * guard band ...
 609                 */
 610                if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 611                    ktime_after(guard, entry->close_time)) {
 612                        skb = NULL;
 613                        continue;
 614                }
 615
 616                /* ... and no budget. */
 617                if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
 618                    atomic_sub_return(len, &entry->budget) < 0) {
 619                        skb = NULL;
 620                        continue;
 621                }
 622
 623                skb = child->ops->dequeue(child);
 624                if (unlikely(!skb))
 625                        goto done;
 626
 627skb_found:
 628                qdisc_bstats_update(sch, skb);
 629                qdisc_qstats_backlog_dec(sch, skb);
 630                sch->q.qlen--;
 631
 632                goto done;
 633        }
 634
 635done:
 636        rcu_read_unlock();
 637
 638        return skb;
 639}
 640
 641static struct sk_buff *taprio_dequeue_offload(struct Qdisc *sch)
 642{
 643        WARN_ONCE(1, "Trying to dequeue from the root of a taprio qdisc configured with full offload\n");
 644
 645        return NULL;
 646}
 647
 648static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 649{
 650        struct taprio_sched *q = qdisc_priv(sch);
 651
 652        return q->dequeue(sch);
 653}
 654
 655static bool should_restart_cycle(const struct sched_gate_list *oper,
 656                                 const struct sched_entry *entry)
 657{
 658        if (list_is_last(&entry->list, &oper->entries))
 659                return true;
 660
 661        if (ktime_compare(entry->close_time, oper->cycle_close_time) == 0)
 662                return true;
 663
 664        return false;
 665}
 666
 667static bool should_change_schedules(const struct sched_gate_list *admin,
 668                                    const struct sched_gate_list *oper,
 669                                    ktime_t close_time)
 670{
 671        ktime_t next_base_time, extension_time;
 672
 673        if (!admin)
 674                return false;
 675
 676        next_base_time = sched_base_time(admin);
 677
 678        /* This is the simple case, the close_time would fall after
 679         * the next schedule base_time.
 680         */
 681        if (ktime_compare(next_base_time, close_time) <= 0)
 682                return true;
 683
 684        /* This is the cycle_time_extension case, if the close_time
 685         * plus the amount that can be extended would fall after the
 686         * next schedule base_time, we can extend the current schedule
 687         * for that amount.
 688         */
 689        extension_time = ktime_add_ns(close_time, oper->cycle_time_extension);
 690
 691        /* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about
 692         * how precisely the extension should be made. So after
 693         * conformance testing, this logic may change.
 694         */
 695        if (ktime_compare(next_base_time, extension_time) <= 0)
 696                return true;
 697
 698        return false;
 699}
 700
 701static enum hrtimer_restart advance_sched(struct hrtimer *timer)
 702{
 703        struct taprio_sched *q = container_of(timer, struct taprio_sched,
 704                                              advance_timer);
 705        struct sched_gate_list *oper, *admin;
 706        struct sched_entry *entry, *next;
 707        struct Qdisc *sch = q->root;
 708        ktime_t close_time;
 709
 710        spin_lock(&q->current_entry_lock);
 711        entry = rcu_dereference_protected(q->current_entry,
 712                                          lockdep_is_held(&q->current_entry_lock));
 713        oper = rcu_dereference_protected(q->oper_sched,
 714                                         lockdep_is_held(&q->current_entry_lock));
 715        admin = rcu_dereference_protected(q->admin_sched,
 716                                          lockdep_is_held(&q->current_entry_lock));
 717
 718        if (!oper)
 719                switch_schedules(q, &admin, &oper);
 720
 721        /* This can happen in two cases: 1. this is the very first run
 722         * of this function (i.e. we weren't running any schedule
 723         * previously); 2. The previous schedule just ended. The first
 724         * entry of all schedules are pre-calculated during the
 725         * schedule initialization.
 726         */
 727        if (unlikely(!entry || entry->close_time == oper->base_time)) {
 728                next = list_first_entry(&oper->entries, struct sched_entry,
 729                                        list);
 730                close_time = next->close_time;
 731                goto first_run;
 732        }
 733
 734        if (should_restart_cycle(oper, entry)) {
 735                next = list_first_entry(&oper->entries, struct sched_entry,
 736                                        list);
 737                oper->cycle_close_time = ktime_add_ns(oper->cycle_close_time,
 738                                                      oper->cycle_time);
 739        } else {
 740                next = list_next_entry(entry, list);
 741        }
 742
 743        close_time = ktime_add_ns(entry->close_time, next->interval);
 744        close_time = min_t(ktime_t, close_time, oper->cycle_close_time);
 745
 746        if (should_change_schedules(admin, oper, close_time)) {
 747                /* Set things so the next time this runs, the new
 748                 * schedule runs.
 749                 */
 750                close_time = sched_base_time(admin);
 751                switch_schedules(q, &admin, &oper);
 752        }
 753
 754        next->close_time = close_time;
 755        taprio_set_budget(q, next);
 756
 757first_run:
 758        rcu_assign_pointer(q->current_entry, next);
 759        spin_unlock(&q->current_entry_lock);
 760
 761        hrtimer_set_expires(&q->advance_timer, close_time);
 762
 763        rcu_read_lock();
 764        __netif_schedule(sch);
 765        rcu_read_unlock();
 766
 767        return HRTIMER_RESTART;
 768}
 769
 770static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = {
 771        [TCA_TAPRIO_SCHED_ENTRY_INDEX]     = { .type = NLA_U32 },
 772        [TCA_TAPRIO_SCHED_ENTRY_CMD]       = { .type = NLA_U8 },
 773        [TCA_TAPRIO_SCHED_ENTRY_GATE_MASK] = { .type = NLA_U32 },
 774        [TCA_TAPRIO_SCHED_ENTRY_INTERVAL]  = { .type = NLA_U32 },
 775};
 776
 777static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = {
 778        [TCA_TAPRIO_ATTR_PRIOMAP]              = {
 779                .len = sizeof(struct tc_mqprio_qopt)
 780        },
 781        [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST]           = { .type = NLA_NESTED },
 782        [TCA_TAPRIO_ATTR_SCHED_BASE_TIME]            = { .type = NLA_S64 },
 783        [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]         = { .type = NLA_NESTED },
 784        [TCA_TAPRIO_ATTR_SCHED_CLOCKID]              = { .type = NLA_S32 },
 785        [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]           = { .type = NLA_S64 },
 786        [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
 787        [TCA_TAPRIO_ATTR_FLAGS]                      = { .type = NLA_U32 },
 788        [TCA_TAPRIO_ATTR_TXTIME_DELAY]               = { .type = NLA_U32 },
 789};
 790
 791static int fill_sched_entry(struct taprio_sched *q, struct nlattr **tb,
 792                            struct sched_entry *entry,
 793                            struct netlink_ext_ack *extack)
 794{
 795        int min_duration = length_to_duration(q, ETH_ZLEN);
 796        u32 interval = 0;
 797
 798        if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
 799                entry->command = nla_get_u8(
 800                        tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
 801
 802        if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
 803                entry->gate_mask = nla_get_u32(
 804                        tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
 805
 806        if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
 807                interval = nla_get_u32(
 808                        tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
 809
 810        /* The interval should allow at least the minimum ethernet
 811         * frame to go out.
 812         */
 813        if (interval < min_duration) {
 814                NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
 815                return -EINVAL;
 816        }
 817
 818        entry->interval = interval;
 819
 820        return 0;
 821}
 822
 823static int parse_sched_entry(struct taprio_sched *q, struct nlattr *n,
 824                             struct sched_entry *entry, int index,
 825                             struct netlink_ext_ack *extack)
 826{
 827        struct nlattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { };
 828        int err;
 829
 830        err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, n,
 831                                          entry_policy, NULL);
 832        if (err < 0) {
 833                NL_SET_ERR_MSG(extack, "Could not parse nested entry");
 834                return -EINVAL;
 835        }
 836
 837        entry->index = index;
 838
 839        return fill_sched_entry(q, tb, entry, extack);
 840}
 841
 842static int parse_sched_list(struct taprio_sched *q, struct nlattr *list,
 843                            struct sched_gate_list *sched,
 844                            struct netlink_ext_ack *extack)
 845{
 846        struct nlattr *n;
 847        int err, rem;
 848        int i = 0;
 849
 850        if (!list)
 851                return -EINVAL;
 852
 853        nla_for_each_nested(n, list, rem) {
 854                struct sched_entry *entry;
 855
 856                if (nla_type(n) != TCA_TAPRIO_SCHED_ENTRY) {
 857                        NL_SET_ERR_MSG(extack, "Attribute is not of type 'entry'");
 858                        continue;
 859                }
 860
 861                entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 862                if (!entry) {
 863                        NL_SET_ERR_MSG(extack, "Not enough memory for entry");
 864                        return -ENOMEM;
 865                }
 866
 867                err = parse_sched_entry(q, n, entry, i, extack);
 868                if (err < 0) {
 869                        kfree(entry);
 870                        return err;
 871                }
 872
 873                list_add_tail(&entry->list, &sched->entries);
 874                i++;
 875        }
 876
 877        sched->num_entries = i;
 878
 879        return i;
 880}
 881
 882static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
 883                                 struct sched_gate_list *new,
 884                                 struct netlink_ext_ack *extack)
 885{
 886        int err = 0;
 887
 888        if (tb[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]) {
 889                NL_SET_ERR_MSG(extack, "Adding a single entry is not supported");
 890                return -ENOTSUPP;
 891        }
 892
 893        if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
 894                new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
 895
 896        if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
 897                new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
 898
 899        if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
 900                new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
 901
 902        if (tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST])
 903                err = parse_sched_list(q, tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST],
 904                                       new, extack);
 905        if (err < 0)
 906                return err;
 907
 908        if (!new->cycle_time) {
 909                struct sched_entry *entry;
 910                ktime_t cycle = 0;
 911
 912                list_for_each_entry(entry, &new->entries, list)
 913                        cycle = ktime_add_ns(cycle, entry->interval);
 914
 915                if (!cycle) {
 916                        NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0");
 917                        return -EINVAL;
 918                }
 919
 920                new->cycle_time = cycle;
 921        }
 922
 923        return 0;
 924}
 925
 926static int taprio_parse_mqprio_opt(struct net_device *dev,
 927                                   struct tc_mqprio_qopt *qopt,
 928                                   struct netlink_ext_ack *extack,
 929                                   u32 taprio_flags)
 930{
 931        int i, j;
 932
 933        if (!qopt && !dev->num_tc) {
 934                NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
 935                return -EINVAL;
 936        }
 937
 938        /* If num_tc is already set, it means that the user already
 939         * configured the mqprio part
 940         */
 941        if (dev->num_tc)
 942                return 0;
 943
 944        /* Verify num_tc is not out of max range */
 945        if (qopt->num_tc > TC_MAX_QUEUE) {
 946                NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
 947                return -EINVAL;
 948        }
 949
 950        /* taprio imposes that traffic classes map 1:n to tx queues */
 951        if (qopt->num_tc > dev->num_tx_queues) {
 952                NL_SET_ERR_MSG(extack, "Number of traffic classes is greater than number of HW queues");
 953                return -EINVAL;
 954        }
 955
 956        /* Verify priority mapping uses valid tcs */
 957        for (i = 0; i <= TC_BITMASK; i++) {
 958                if (qopt->prio_tc_map[i] >= qopt->num_tc) {
 959                        NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping");
 960                        return -EINVAL;
 961                }
 962        }
 963
 964        for (i = 0; i < qopt->num_tc; i++) {
 965                unsigned int last = qopt->offset[i] + qopt->count[i];
 966
 967                /* Verify the queue count is in tx range being equal to the
 968                 * real_num_tx_queues indicates the last queue is in use.
 969                 */
 970                if (qopt->offset[i] >= dev->num_tx_queues ||
 971                    !qopt->count[i] ||
 972                    last > dev->real_num_tx_queues) {
 973                        NL_SET_ERR_MSG(extack, "Invalid queue in traffic class to queue mapping");
 974                        return -EINVAL;
 975                }
 976
 977                if (TXTIME_ASSIST_IS_ENABLED(taprio_flags))
 978                        continue;
 979
 980                /* Verify that the offset and counts do not overlap */
 981                for (j = i + 1; j < qopt->num_tc; j++) {
 982                        if (last > qopt->offset[j]) {
 983                                NL_SET_ERR_MSG(extack, "Detected overlap in the traffic class to queue mapping");
 984                                return -EINVAL;
 985                        }
 986                }
 987        }
 988
 989        return 0;
 990}
 991
 992static int taprio_get_start_time(struct Qdisc *sch,
 993                                 struct sched_gate_list *sched,
 994                                 ktime_t *start)
 995{
 996        struct taprio_sched *q = qdisc_priv(sch);
 997        ktime_t now, base, cycle;
 998        s64 n;
 999
1000        base = sched_base_time(sched);
1001        now = taprio_get_time(q);
1002
1003        if (ktime_after(base, now)) {
1004                *start = base;
1005                return 0;
1006        }
1007
1008        cycle = sched->cycle_time;
1009
1010        /* The qdisc is expected to have at least one sched_entry.  Moreover,
1011         * any entry must have 'interval' > 0. Thus if the cycle time is zero,
1012         * something went really wrong. In that case, we should warn about this
1013         * inconsistent state and return error.
1014         */
1015        if (WARN_ON(!cycle))
1016                return -EFAULT;
1017
1018        /* Schedule the start time for the beginning of the next
1019         * cycle.
1020         */
1021        n = div64_s64(ktime_sub_ns(now, base), cycle);
1022        *start = ktime_add_ns(base, (n + 1) * cycle);
1023        return 0;
1024}
1025
1026static void setup_first_close_time(struct taprio_sched *q,
1027                                   struct sched_gate_list *sched, ktime_t base)
1028{
1029        struct sched_entry *first;
1030        ktime_t cycle;
1031
1032        first = list_first_entry(&sched->entries,
1033                                 struct sched_entry, list);
1034
1035        cycle = sched->cycle_time;
1036
1037        /* FIXME: find a better place to do this */
1038        sched->cycle_close_time = ktime_add_ns(base, cycle);
1039
1040        first->close_time = ktime_add_ns(base, first->interval);
1041        taprio_set_budget(q, first);
1042        rcu_assign_pointer(q->current_entry, NULL);
1043}
1044
1045static void taprio_start_sched(struct Qdisc *sch,
1046                               ktime_t start, struct sched_gate_list *new)
1047{
1048        struct taprio_sched *q = qdisc_priv(sch);
1049        ktime_t expires;
1050
1051        if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1052                return;
1053
1054        expires = hrtimer_get_expires(&q->advance_timer);
1055        if (expires == 0)
1056                expires = KTIME_MAX;
1057
1058        /* If the new schedule starts before the next expiration, we
1059         * reprogram it to the earliest one, so we change the admin
1060         * schedule to the operational one at the right time.
1061         */
1062        start = min_t(ktime_t, start, expires);
1063
1064        hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS);
1065}
1066
1067static void taprio_set_picos_per_byte(struct net_device *dev,
1068                                      struct taprio_sched *q)
1069{
1070        struct ethtool_link_ksettings ecmd;
1071        int speed = SPEED_10;
1072        int picos_per_byte;
1073        int err;
1074
1075        err = __ethtool_get_link_ksettings(dev, &ecmd);
1076        if (err < 0)
1077                goto skip;
1078
1079        if (ecmd.base.speed && ecmd.base.speed != SPEED_UNKNOWN)
1080                speed = ecmd.base.speed;
1081
1082skip:
1083        picos_per_byte = (USEC_PER_SEC * 8) / speed;
1084
1085        atomic64_set(&q->picos_per_byte, picos_per_byte);
1086        netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
1087                   dev->name, (long long)atomic64_read(&q->picos_per_byte),
1088                   ecmd.base.speed);
1089}
1090
1091static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
1092                               void *ptr)
1093{
1094        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1095        struct net_device *qdev;
1096        struct taprio_sched *q;
1097        bool found = false;
1098
1099        ASSERT_RTNL();
1100
1101        if (event != NETDEV_UP && event != NETDEV_CHANGE)
1102                return NOTIFY_DONE;
1103
1104        spin_lock(&taprio_list_lock);
1105        list_for_each_entry(q, &taprio_list, taprio_list) {
1106                qdev = qdisc_dev(q->root);
1107                if (qdev == dev) {
1108                        found = true;
1109                        break;
1110                }
1111        }
1112        spin_unlock(&taprio_list_lock);
1113
1114        if (found)
1115                taprio_set_picos_per_byte(dev, q);
1116
1117        return NOTIFY_DONE;
1118}
1119
1120static void setup_txtime(struct taprio_sched *q,
1121                         struct sched_gate_list *sched, ktime_t base)
1122{
1123        struct sched_entry *entry;
1124        u32 interval = 0;
1125
1126        list_for_each_entry(entry, &sched->entries, list) {
1127                entry->next_txtime = ktime_add_ns(base, interval);
1128                interval += entry->interval;
1129        }
1130}
1131
1132static struct tc_taprio_qopt_offload *taprio_offload_alloc(int num_entries)
1133{
1134        struct __tc_taprio_qopt_offload *__offload;
1135
1136        __offload = kzalloc(struct_size(__offload, offload.entries, num_entries),
1137                            GFP_KERNEL);
1138        if (!__offload)
1139                return NULL;
1140
1141        refcount_set(&__offload->users, 1);
1142
1143        return &__offload->offload;
1144}
1145
1146struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
1147                                                  *offload)
1148{
1149        struct __tc_taprio_qopt_offload *__offload;
1150
1151        __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1152                                 offload);
1153
1154        refcount_inc(&__offload->users);
1155
1156        return offload;
1157}
1158EXPORT_SYMBOL_GPL(taprio_offload_get);
1159
1160void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
1161{
1162        struct __tc_taprio_qopt_offload *__offload;
1163
1164        __offload = container_of(offload, struct __tc_taprio_qopt_offload,
1165                                 offload);
1166
1167        if (!refcount_dec_and_test(&__offload->users))
1168                return;
1169
1170        kfree(__offload);
1171}
1172EXPORT_SYMBOL_GPL(taprio_offload_free);
1173
1174/* The function will only serve to keep the pointers to the "oper" and "admin"
1175 * schedules valid in relation to their base times, so when calling dump() the
1176 * users looks at the right schedules.
1177 * When using full offload, the admin configuration is promoted to oper at the
1178 * base_time in the PHC time domain.  But because the system time is not
1179 * necessarily in sync with that, we can't just trigger a hrtimer to call
1180 * switch_schedules at the right hardware time.
1181 * At the moment we call this by hand right away from taprio, but in the future
1182 * it will be useful to create a mechanism for drivers to notify taprio of the
1183 * offload state (PENDING, ACTIVE, INACTIVE) so it can be visible in dump().
1184 * This is left as TODO.
1185 */
1186static void taprio_offload_config_changed(struct taprio_sched *q)
1187{
1188        struct sched_gate_list *oper, *admin;
1189
1190        spin_lock(&q->current_entry_lock);
1191
1192        oper = rcu_dereference_protected(q->oper_sched,
1193                                         lockdep_is_held(&q->current_entry_lock));
1194        admin = rcu_dereference_protected(q->admin_sched,
1195                                          lockdep_is_held(&q->current_entry_lock));
1196
1197        switch_schedules(q, &admin, &oper);
1198
1199        spin_unlock(&q->current_entry_lock);
1200}
1201
1202static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask)
1203{
1204        u32 i, queue_mask = 0;
1205
1206        for (i = 0; i < dev->num_tc; i++) {
1207                u32 offset, count;
1208
1209                if (!(tc_mask & BIT(i)))
1210                        continue;
1211
1212                offset = dev->tc_to_txq[i].offset;
1213                count = dev->tc_to_txq[i].count;
1214
1215                queue_mask |= GENMASK(offset + count - 1, offset);
1216        }
1217
1218        return queue_mask;
1219}
1220
1221static void taprio_sched_to_offload(struct net_device *dev,
1222                                    struct sched_gate_list *sched,
1223                                    struct tc_taprio_qopt_offload *offload)
1224{
1225        struct sched_entry *entry;
1226        int i = 0;
1227
1228        offload->base_time = sched->base_time;
1229        offload->cycle_time = sched->cycle_time;
1230        offload->cycle_time_extension = sched->cycle_time_extension;
1231
1232        list_for_each_entry(entry, &sched->entries, list) {
1233                struct tc_taprio_sched_entry *e = &offload->entries[i];
1234
1235                e->command = entry->command;
1236                e->interval = entry->interval;
1237                e->gate_mask = tc_map_to_queue_mask(dev, entry->gate_mask);
1238
1239                i++;
1240        }
1241
1242        offload->num_entries = i;
1243}
1244
1245static int taprio_enable_offload(struct net_device *dev,
1246                                 struct taprio_sched *q,
1247                                 struct sched_gate_list *sched,
1248                                 struct netlink_ext_ack *extack)
1249{
1250        const struct net_device_ops *ops = dev->netdev_ops;
1251        struct tc_taprio_qopt_offload *offload;
1252        int err = 0;
1253
1254        if (!ops->ndo_setup_tc) {
1255                NL_SET_ERR_MSG(extack,
1256                               "Device does not support taprio offload");
1257                return -EOPNOTSUPP;
1258        }
1259
1260        offload = taprio_offload_alloc(sched->num_entries);
1261        if (!offload) {
1262                NL_SET_ERR_MSG(extack,
1263                               "Not enough memory for enabling offload mode");
1264                return -ENOMEM;
1265        }
1266        offload->enable = 1;
1267        taprio_sched_to_offload(dev, sched, offload);
1268
1269        err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1270        if (err < 0) {
1271                NL_SET_ERR_MSG(extack,
1272                               "Device failed to setup taprio offload");
1273                goto done;
1274        }
1275
1276done:
1277        taprio_offload_free(offload);
1278
1279        return err;
1280}
1281
1282static int taprio_disable_offload(struct net_device *dev,
1283                                  struct taprio_sched *q,
1284                                  struct netlink_ext_ack *extack)
1285{
1286        const struct net_device_ops *ops = dev->netdev_ops;
1287        struct tc_taprio_qopt_offload *offload;
1288        int err;
1289
1290        if (!FULL_OFFLOAD_IS_ENABLED(q->flags))
1291                return 0;
1292
1293        if (!ops->ndo_setup_tc)
1294                return -EOPNOTSUPP;
1295
1296        offload = taprio_offload_alloc(0);
1297        if (!offload) {
1298                NL_SET_ERR_MSG(extack,
1299                               "Not enough memory to disable offload mode");
1300                return -ENOMEM;
1301        }
1302        offload->enable = 0;
1303
1304        err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
1305        if (err < 0) {
1306                NL_SET_ERR_MSG(extack,
1307                               "Device failed to disable offload");
1308                goto out;
1309        }
1310
1311out:
1312        taprio_offload_free(offload);
1313
1314        return err;
1315}
1316
1317/* If full offload is enabled, the only possible clockid is the net device's
1318 * PHC. For that reason, specifying a clockid through netlink is incorrect.
1319 * For txtime-assist, it is implicitly assumed that the device's PHC is kept
1320 * in sync with the specified clockid via a user space daemon such as phc2sys.
1321 * For both software taprio and txtime-assist, the clockid is used for the
1322 * hrtimer that advances the schedule and hence mandatory.
1323 */
1324static int taprio_parse_clockid(struct Qdisc *sch, struct nlattr **tb,
1325                                struct netlink_ext_ack *extack)
1326{
1327        struct taprio_sched *q = qdisc_priv(sch);
1328        struct net_device *dev = qdisc_dev(sch);
1329        int err = -EINVAL;
1330
1331        if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1332                const struct ethtool_ops *ops = dev->ethtool_ops;
1333                struct ethtool_ts_info info = {
1334                        .cmd = ETHTOOL_GET_TS_INFO,
1335                        .phc_index = -1,
1336                };
1337
1338                if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1339                        NL_SET_ERR_MSG(extack,
1340                                       "The 'clockid' cannot be specified for full offload");
1341                        goto out;
1342                }
1343
1344                if (ops && ops->get_ts_info)
1345                        err = ops->get_ts_info(dev, &info);
1346
1347                if (err || info.phc_index < 0) {
1348                        NL_SET_ERR_MSG(extack,
1349                                       "Device does not have a PTP clock");
1350                        err = -ENOTSUPP;
1351                        goto out;
1352                }
1353        } else if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
1354                int clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
1355
1356                /* We only support static clockids and we don't allow
1357                 * for it to be modified after the first init.
1358                 */
1359                if (clockid < 0 ||
1360                    (q->clockid != -1 && q->clockid != clockid)) {
1361                        NL_SET_ERR_MSG(extack,
1362                                       "Changing the 'clockid' of a running schedule is not supported");
1363                        err = -ENOTSUPP;
1364                        goto out;
1365                }
1366
1367                switch (clockid) {
1368                case CLOCK_REALTIME:
1369                        q->tk_offset = TK_OFFS_REAL;
1370                        break;
1371                case CLOCK_MONOTONIC:
1372                        q->tk_offset = TK_OFFS_MAX;
1373                        break;
1374                case CLOCK_BOOTTIME:
1375                        q->tk_offset = TK_OFFS_BOOT;
1376                        break;
1377                case CLOCK_TAI:
1378                        q->tk_offset = TK_OFFS_TAI;
1379                        break;
1380                default:
1381                        NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
1382                        err = -EINVAL;
1383                        goto out;
1384                }
1385
1386                q->clockid = clockid;
1387        } else {
1388                NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
1389                goto out;
1390        }
1391
1392        /* Everything went ok, return success. */
1393        err = 0;
1394
1395out:
1396        return err;
1397}
1398
1399static int taprio_mqprio_cmp(const struct net_device *dev,
1400                             const struct tc_mqprio_qopt *mqprio)
1401{
1402        int i;
1403
1404        if (!mqprio || mqprio->num_tc != dev->num_tc)
1405                return -1;
1406
1407        for (i = 0; i < mqprio->num_tc; i++)
1408                if (dev->tc_to_txq[i].count != mqprio->count[i] ||
1409                    dev->tc_to_txq[i].offset != mqprio->offset[i])
1410                        return -1;
1411
1412        for (i = 0; i <= TC_BITMASK; i++)
1413                if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
1414                        return -1;
1415
1416        return 0;
1417}
1418
1419/* The semantics of the 'flags' argument in relation to 'change()'
1420 * requests, are interpreted following two rules (which are applied in
1421 * this order): (1) an omitted 'flags' argument is interpreted as
1422 * zero; (2) the 'flags' of a "running" taprio instance cannot be
1423 * changed.
1424 */
1425static int taprio_new_flags(const struct nlattr *attr, u32 old,
1426                            struct netlink_ext_ack *extack)
1427{
1428        u32 new = 0;
1429
1430        if (attr)
1431                new = nla_get_u32(attr);
1432
1433        if (old != TAPRIO_FLAGS_INVALID && old != new) {
1434                NL_SET_ERR_MSG_MOD(extack, "Changing 'flags' of a running schedule is not supported");
1435                return -EOPNOTSUPP;
1436        }
1437
1438        if (!taprio_flags_valid(new)) {
1439                NL_SET_ERR_MSG_MOD(extack, "Specified 'flags' are not valid");
1440                return -EINVAL;
1441        }
1442
1443        return new;
1444}
1445
1446static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
1447                         struct netlink_ext_ack *extack)
1448{
1449        struct nlattr *tb[TCA_TAPRIO_ATTR_MAX + 1] = { };
1450        struct sched_gate_list *oper, *admin, *new_admin;
1451        struct taprio_sched *q = qdisc_priv(sch);
1452        struct net_device *dev = qdisc_dev(sch);
1453        struct tc_mqprio_qopt *mqprio = NULL;
1454        unsigned long flags;
1455        ktime_t start;
1456        int i, err;
1457
1458        err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_ATTR_MAX, opt,
1459                                          taprio_policy, extack);
1460        if (err < 0)
1461                return err;
1462
1463        if (tb[TCA_TAPRIO_ATTR_PRIOMAP])
1464                mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]);
1465
1466        err = taprio_new_flags(tb[TCA_TAPRIO_ATTR_FLAGS],
1467                               q->flags, extack);
1468        if (err < 0)
1469                return err;
1470
1471        q->flags = err;
1472
1473        err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags);
1474        if (err < 0)
1475                return err;
1476
1477        new_admin = kzalloc(sizeof(*new_admin), GFP_KERNEL);
1478        if (!new_admin) {
1479                NL_SET_ERR_MSG(extack, "Not enough memory for a new schedule");
1480                return -ENOMEM;
1481        }
1482        INIT_LIST_HEAD(&new_admin->entries);
1483
1484        rcu_read_lock();
1485        oper = rcu_dereference(q->oper_sched);
1486        admin = rcu_dereference(q->admin_sched);
1487        rcu_read_unlock();
1488
1489        /* no changes - no new mqprio settings */
1490        if (!taprio_mqprio_cmp(dev, mqprio))
1491                mqprio = NULL;
1492
1493        if (mqprio && (oper || admin)) {
1494                NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
1495                err = -ENOTSUPP;
1496                goto free_sched;
1497        }
1498
1499        err = parse_taprio_schedule(q, tb, new_admin, extack);
1500        if (err < 0)
1501                goto free_sched;
1502
1503        if (new_admin->num_entries == 0) {
1504                NL_SET_ERR_MSG(extack, "There should be at least one entry in the schedule");
1505                err = -EINVAL;
1506                goto free_sched;
1507        }
1508
1509        err = taprio_parse_clockid(sch, tb, extack);
1510        if (err < 0)
1511                goto free_sched;
1512
1513        taprio_set_picos_per_byte(dev, q);
1514
1515        if (mqprio) {
1516                netdev_set_num_tc(dev, mqprio->num_tc);
1517                for (i = 0; i < mqprio->num_tc; i++)
1518                        netdev_set_tc_queue(dev, i,
1519                                            mqprio->count[i],
1520                                            mqprio->offset[i]);
1521
1522                /* Always use supplied priority mappings */
1523                for (i = 0; i <= TC_BITMASK; i++)
1524                        netdev_set_prio_tc_map(dev, i,
1525                                               mqprio->prio_tc_map[i]);
1526        }
1527
1528        if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1529                err = taprio_enable_offload(dev, q, new_admin, extack);
1530        else
1531                err = taprio_disable_offload(dev, q, extack);
1532        if (err)
1533                goto free_sched;
1534
1535        /* Protects against enqueue()/dequeue() */
1536        spin_lock_bh(qdisc_lock(sch));
1537
1538        if (tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]) {
1539                if (!TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1540                        NL_SET_ERR_MSG_MOD(extack, "txtime-delay can only be set when txtime-assist mode is enabled");
1541                        err = -EINVAL;
1542                        goto unlock;
1543                }
1544
1545                q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
1546        }
1547
1548        if (!TXTIME_ASSIST_IS_ENABLED(q->flags) &&
1549            !FULL_OFFLOAD_IS_ENABLED(q->flags) &&
1550            !hrtimer_active(&q->advance_timer)) {
1551                hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
1552                q->advance_timer.function = advance_sched;
1553        }
1554
1555        if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1556                q->dequeue = taprio_dequeue_offload;
1557                q->peek = taprio_peek_offload;
1558        } else {
1559                /* Be sure to always keep the function pointers
1560                 * in a consistent state.
1561                 */
1562                q->dequeue = taprio_dequeue_soft;
1563                q->peek = taprio_peek_soft;
1564        }
1565
1566        err = taprio_get_start_time(sch, new_admin, &start);
1567        if (err < 0) {
1568                NL_SET_ERR_MSG(extack, "Internal error: failed get start time");
1569                goto unlock;
1570        }
1571
1572        setup_txtime(q, new_admin, start);
1573
1574        if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
1575                if (!oper) {
1576                        rcu_assign_pointer(q->oper_sched, new_admin);
1577                        err = 0;
1578                        new_admin = NULL;
1579                        goto unlock;
1580                }
1581
1582                rcu_assign_pointer(q->admin_sched, new_admin);
1583                if (admin)
1584                        call_rcu(&admin->rcu, taprio_free_sched_cb);
1585        } else {
1586                setup_first_close_time(q, new_admin, start);
1587
1588                /* Protects against advance_sched() */
1589                spin_lock_irqsave(&q->current_entry_lock, flags);
1590
1591                taprio_start_sched(sch, start, new_admin);
1592
1593                rcu_assign_pointer(q->admin_sched, new_admin);
1594                if (admin)
1595                        call_rcu(&admin->rcu, taprio_free_sched_cb);
1596
1597                spin_unlock_irqrestore(&q->current_entry_lock, flags);
1598
1599                if (FULL_OFFLOAD_IS_ENABLED(q->flags))
1600                        taprio_offload_config_changed(q);
1601        }
1602
1603        new_admin = NULL;
1604        err = 0;
1605
1606unlock:
1607        spin_unlock_bh(qdisc_lock(sch));
1608
1609free_sched:
1610        if (new_admin)
1611                call_rcu(&new_admin->rcu, taprio_free_sched_cb);
1612
1613        return err;
1614}
1615
1616static void taprio_reset(struct Qdisc *sch)
1617{
1618        struct taprio_sched *q = qdisc_priv(sch);
1619        struct net_device *dev = qdisc_dev(sch);
1620        int i;
1621
1622        hrtimer_cancel(&q->advance_timer);
1623        if (q->qdiscs) {
1624                for (i = 0; i < dev->num_tx_queues; i++)
1625                        if (q->qdiscs[i])
1626                                qdisc_reset(q->qdiscs[i]);
1627        }
1628        sch->qstats.backlog = 0;
1629        sch->q.qlen = 0;
1630}
1631
1632static void taprio_destroy(struct Qdisc *sch)
1633{
1634        struct taprio_sched *q = qdisc_priv(sch);
1635        struct net_device *dev = qdisc_dev(sch);
1636        unsigned int i;
1637
1638        spin_lock(&taprio_list_lock);
1639        list_del(&q->taprio_list);
1640        spin_unlock(&taprio_list_lock);
1641
1642
1643        taprio_disable_offload(dev, q, NULL);
1644
1645        if (q->qdiscs) {
1646                for (i = 0; i < dev->num_tx_queues; i++)
1647                        qdisc_put(q->qdiscs[i]);
1648
1649                kfree(q->qdiscs);
1650        }
1651        q->qdiscs = NULL;
1652
1653        netdev_reset_tc(dev);
1654
1655        if (q->oper_sched)
1656                call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);
1657
1658        if (q->admin_sched)
1659                call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb);
1660}
1661
1662static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
1663                       struct netlink_ext_ack *extack)
1664{
1665        struct taprio_sched *q = qdisc_priv(sch);
1666        struct net_device *dev = qdisc_dev(sch);
1667        int i;
1668
1669        spin_lock_init(&q->current_entry_lock);
1670
1671        hrtimer_init(&q->advance_timer, CLOCK_TAI, HRTIMER_MODE_ABS);
1672        q->advance_timer.function = advance_sched;
1673
1674        q->dequeue = taprio_dequeue_soft;
1675        q->peek = taprio_peek_soft;
1676
1677        q->root = sch;
1678
1679        /* We only support static clockids. Use an invalid value as default
1680         * and get the valid one on taprio_change().
1681         */
1682        q->clockid = -1;
1683        q->flags = TAPRIO_FLAGS_INVALID;
1684
1685        spin_lock(&taprio_list_lock);
1686        list_add(&q->taprio_list, &taprio_list);
1687        spin_unlock(&taprio_list_lock);
1688
1689        if (sch->parent != TC_H_ROOT)
1690                return -EOPNOTSUPP;
1691
1692        if (!netif_is_multiqueue(dev))
1693                return -EOPNOTSUPP;
1694
1695        /* pre-allocate qdisc, attachment can't fail */
1696        q->qdiscs = kcalloc(dev->num_tx_queues,
1697                            sizeof(q->qdiscs[0]),
1698                            GFP_KERNEL);
1699
1700        if (!q->qdiscs)
1701                return -ENOMEM;
1702
1703        if (!opt)
1704                return -EINVAL;
1705
1706        for (i = 0; i < dev->num_tx_queues; i++) {
1707                struct netdev_queue *dev_queue;
1708                struct Qdisc *qdisc;
1709
1710                dev_queue = netdev_get_tx_queue(dev, i);
1711                qdisc = qdisc_create_dflt(dev_queue,
1712                                          &pfifo_qdisc_ops,
1713                                          TC_H_MAKE(TC_H_MAJ(sch->handle),
1714                                                    TC_H_MIN(i + 1)),
1715                                          extack);
1716                if (!qdisc)
1717                        return -ENOMEM;
1718
1719                if (i < dev->real_num_tx_queues)
1720                        qdisc_hash_add(qdisc, false);
1721
1722                q->qdiscs[i] = qdisc;
1723        }
1724
1725        return taprio_change(sch, opt, extack);
1726}
1727
1728static void taprio_attach(struct Qdisc *sch)
1729{
1730        struct taprio_sched *q = qdisc_priv(sch);
1731        struct net_device *dev = qdisc_dev(sch);
1732        unsigned int ntx;
1733
1734        /* Attach underlying qdisc */
1735        for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
1736                struct Qdisc *qdisc = q->qdiscs[ntx];
1737                struct Qdisc *old;
1738
1739                if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1740                        qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1741                        old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
1742                } else {
1743                        old = dev_graft_qdisc(qdisc->dev_queue, sch);
1744                        qdisc_refcount_inc(sch);
1745                }
1746                if (old)
1747                        qdisc_put(old);
1748        }
1749
1750        /* access to the child qdiscs is not needed in offload mode */
1751        if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1752                kfree(q->qdiscs);
1753                q->qdiscs = NULL;
1754        }
1755}
1756
1757static struct netdev_queue *taprio_queue_get(struct Qdisc *sch,
1758                                             unsigned long cl)
1759{
1760        struct net_device *dev = qdisc_dev(sch);
1761        unsigned long ntx = cl - 1;
1762
1763        if (ntx >= dev->num_tx_queues)
1764                return NULL;
1765
1766        return netdev_get_tx_queue(dev, ntx);
1767}
1768
1769static int taprio_graft(struct Qdisc *sch, unsigned long cl,
1770                        struct Qdisc *new, struct Qdisc **old,
1771                        struct netlink_ext_ack *extack)
1772{
1773        struct taprio_sched *q = qdisc_priv(sch);
1774        struct net_device *dev = qdisc_dev(sch);
1775        struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1776
1777        if (!dev_queue)
1778                return -EINVAL;
1779
1780        if (dev->flags & IFF_UP)
1781                dev_deactivate(dev);
1782
1783        if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
1784                *old = dev_graft_qdisc(dev_queue, new);
1785        } else {
1786                *old = q->qdiscs[cl - 1];
1787                q->qdiscs[cl - 1] = new;
1788        }
1789
1790        if (new)
1791                new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1792
1793        if (dev->flags & IFF_UP)
1794                dev_activate(dev);
1795
1796        return 0;
1797}
1798
1799static int dump_entry(struct sk_buff *msg,
1800                      const struct sched_entry *entry)
1801{
1802        struct nlattr *item;
1803
1804        item = nla_nest_start_noflag(msg, TCA_TAPRIO_SCHED_ENTRY);
1805        if (!item)
1806                return -ENOSPC;
1807
1808        if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INDEX, entry->index))
1809                goto nla_put_failure;
1810
1811        if (nla_put_u8(msg, TCA_TAPRIO_SCHED_ENTRY_CMD, entry->command))
1812                goto nla_put_failure;
1813
1814        if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_GATE_MASK,
1815                        entry->gate_mask))
1816                goto nla_put_failure;
1817
1818        if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INTERVAL,
1819                        entry->interval))
1820                goto nla_put_failure;
1821
1822        return nla_nest_end(msg, item);
1823
1824nla_put_failure:
1825        nla_nest_cancel(msg, item);
1826        return -1;
1827}
1828
1829static int dump_schedule(struct sk_buff *msg,
1830                         const struct sched_gate_list *root)
1831{
1832        struct nlattr *entry_list;
1833        struct sched_entry *entry;
1834
1835        if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_BASE_TIME,
1836                        root->base_time, TCA_TAPRIO_PAD))
1837                return -1;
1838
1839        if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME,
1840                        root->cycle_time, TCA_TAPRIO_PAD))
1841                return -1;
1842
1843        if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION,
1844                        root->cycle_time_extension, TCA_TAPRIO_PAD))
1845                return -1;
1846
1847        entry_list = nla_nest_start_noflag(msg,
1848                                           TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST);
1849        if (!entry_list)
1850                goto error_nest;
1851
1852        list_for_each_entry(entry, &root->entries, list) {
1853                if (dump_entry(msg, entry) < 0)
1854                        goto error_nest;
1855        }
1856
1857        nla_nest_end(msg, entry_list);
1858        return 0;
1859
1860error_nest:
1861        nla_nest_cancel(msg, entry_list);
1862        return -1;
1863}
1864
1865static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
1866{
1867        struct taprio_sched *q = qdisc_priv(sch);
1868        struct net_device *dev = qdisc_dev(sch);
1869        struct sched_gate_list *oper, *admin;
1870        struct tc_mqprio_qopt opt = { 0 };
1871        struct nlattr *nest, *sched_nest;
1872        unsigned int i;
1873
1874        rcu_read_lock();
1875        oper = rcu_dereference(q->oper_sched);
1876        admin = rcu_dereference(q->admin_sched);
1877
1878        opt.num_tc = netdev_get_num_tc(dev);
1879        memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
1880
1881        for (i = 0; i < netdev_get_num_tc(dev); i++) {
1882                opt.count[i] = dev->tc_to_txq[i].count;
1883                opt.offset[i] = dev->tc_to_txq[i].offset;
1884        }
1885
1886        nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1887        if (!nest)
1888                goto start_error;
1889
1890        if (nla_put(skb, TCA_TAPRIO_ATTR_PRIOMAP, sizeof(opt), &opt))
1891                goto options_error;
1892
1893        if (!FULL_OFFLOAD_IS_ENABLED(q->flags) &&
1894            nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
1895                goto options_error;
1896
1897        if (q->flags && nla_put_u32(skb, TCA_TAPRIO_ATTR_FLAGS, q->flags))
1898                goto options_error;
1899
1900        if (q->txtime_delay &&
1901            nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
1902                goto options_error;
1903
1904        if (oper && dump_schedule(skb, oper))
1905                goto options_error;
1906
1907        if (!admin)
1908                goto done;
1909
1910        sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
1911        if (!sched_nest)
1912                goto options_error;
1913
1914        if (dump_schedule(skb, admin))
1915                goto admin_error;
1916
1917        nla_nest_end(skb, sched_nest);
1918
1919done:
1920        rcu_read_unlock();
1921
1922        return nla_nest_end(skb, nest);
1923
1924admin_error:
1925        nla_nest_cancel(skb, sched_nest);
1926
1927options_error:
1928        nla_nest_cancel(skb, nest);
1929
1930start_error:
1931        rcu_read_unlock();
1932        return -ENOSPC;
1933}
1934
1935static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
1936{
1937        struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1938
1939        if (!dev_queue)
1940                return NULL;
1941
1942        return dev_queue->qdisc_sleeping;
1943}
1944
1945static unsigned long taprio_find(struct Qdisc *sch, u32 classid)
1946{
1947        unsigned int ntx = TC_H_MIN(classid);
1948
1949        if (!taprio_queue_get(sch, ntx))
1950                return 0;
1951        return ntx;
1952}
1953
1954static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
1955                             struct sk_buff *skb, struct tcmsg *tcm)
1956{
1957        struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1958
1959        tcm->tcm_parent = TC_H_ROOT;
1960        tcm->tcm_handle |= TC_H_MIN(cl);
1961        tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
1962
1963        return 0;
1964}
1965
1966static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
1967                                   struct gnet_dump *d)
1968        __releases(d->lock)
1969        __acquires(d->lock)
1970{
1971        struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
1972
1973        sch = dev_queue->qdisc_sleeping;
1974        if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
1975            qdisc_qstats_copy(d, sch) < 0)
1976                return -1;
1977        return 0;
1978}
1979
1980static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1981{
1982        struct net_device *dev = qdisc_dev(sch);
1983        unsigned long ntx;
1984
1985        if (arg->stop)
1986                return;
1987
1988        arg->count = arg->skip;
1989        for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
1990                if (arg->fn(sch, ntx + 1, arg) < 0) {
1991                        arg->stop = 1;
1992                        break;
1993                }
1994                arg->count++;
1995        }
1996}
1997
1998static struct netdev_queue *taprio_select_queue(struct Qdisc *sch,
1999                                                struct tcmsg *tcm)
2000{
2001        return taprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
2002}
2003
2004static const struct Qdisc_class_ops taprio_class_ops = {
2005        .graft          = taprio_graft,
2006        .leaf           = taprio_leaf,
2007        .find           = taprio_find,
2008        .walk           = taprio_walk,
2009        .dump           = taprio_dump_class,
2010        .dump_stats     = taprio_dump_class_stats,
2011        .select_queue   = taprio_select_queue,
2012};
2013
2014static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
2015        .cl_ops         = &taprio_class_ops,
2016        .id             = "taprio",
2017        .priv_size      = sizeof(struct taprio_sched),
2018        .init           = taprio_init,
2019        .change         = taprio_change,
2020        .destroy        = taprio_destroy,
2021        .reset          = taprio_reset,
2022        .attach         = taprio_attach,
2023        .peek           = taprio_peek,
2024        .dequeue        = taprio_dequeue,
2025        .enqueue        = taprio_enqueue,
2026        .dump           = taprio_dump,
2027        .owner          = THIS_MODULE,
2028};
2029
2030static struct notifier_block taprio_device_notifier = {
2031        .notifier_call = taprio_dev_notifier,
2032};
2033
2034static int __init taprio_module_init(void)
2035{
2036        int err = register_netdevice_notifier(&taprio_device_notifier);
2037
2038        if (err)
2039                return err;
2040
2041        return register_qdisc(&taprio_qdisc_ops);
2042}
2043
2044static void __exit taprio_module_exit(void)
2045{
2046        unregister_qdisc(&taprio_qdisc_ops);
2047        unregister_netdevice_notifier(&taprio_device_notifier);
2048}
2049
2050module_init(taprio_module_init);
2051module_exit(taprio_module_exit);
2052MODULE_LICENSE("GPL");
2053