drivers/net/wireless/ath/carl9170/tx.c

   1 /*
   2  * Atheros CARL9170 driver
   3  *
   4  * 802.11 xmit & status routines
   5  *
   6  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
   7  * Copyright 2009, 2010, Christian Lamparter <chunkeey@googlemail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; see the file COPYING.  If not, see
  21  * http://www.gnu.org/licenses/.
  22  *
  23  * This file incorporates work covered by the following copyright and
  24  * permission notice:
  25  *    Copyright (c) 2007-2008 Atheros Communications, Inc.
  26  *
  27  *    Permission to use, copy, modify, and/or distribute this software for any
  28  *    purpose with or without fee is hereby granted, provided that the above
  29  *    copyright notice and this permission notice appear in all copies.
  30  *
  31  *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  32  *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  33  *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  34  *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  35  *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  36  *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  37  *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  38  */
  39
  40 #include <linux/init.h>
  41 #include <linux/slab.h>
  42 #include <linux/module.h>
  43 #include <linux/etherdevice.h>
  44 #include <net/mac80211.h>
  45 #include "carl9170.h"
  46 #include "hw.h"
  47 #include "cmd.h"
  48
  49 static inline unsigned int __carl9170_get_queue(struct ar9170 *ar,
  50                                                 unsigned int queue)
  51 {
  52         if (unlikely(modparam_noht)) {
  53                 return queue;
  54         } else {
  55                 /*
  56                  * This is just another workaround, until
  57                  * someone figures out how to get QoS and
  58                  * AMPDU to play nicely together.
  59                  */
  60
  61                 return 2;               /* AC_BE */
  62         }
  63 }
  64
  65 static inline unsigned int carl9170_get_queue(struct ar9170 *ar,
  66                                               struct sk_buff *skb)
  67 {
  68         return __carl9170_get_queue(ar, skb_get_queue_mapping(skb));
  69 }
  70
  71 static bool is_mem_full(struct ar9170 *ar)
  72 {
  73         return (DIV_ROUND_UP(IEEE80211_MAX_FRAME_LEN, ar->fw.mem_block_size) >
  74                 atomic_read(&ar->mem_free_blocks));
  75 }
  76
  77 static void carl9170_tx_accounting(struct ar9170 *ar, struct sk_buff *skb)
  78 {
  79         int queue, i;
  80         bool mem_full;
  81
  82         atomic_inc(&ar->tx_total_queued);
  83
  84         queue = skb_get_queue_mapping(skb);
  85         spin_lock_bh(&ar->tx_stats_lock);
  86
  87         /*
  88          * The driver has to accept the frame, regardless if the queue is
  89          * full to the brim, or not. We have to do the queuing internally,
  90          * since mac80211 assumes that a driver which can operate with
  91          * aggregated frames does not reject frames for this reason.
  92          */
  93         ar->tx_stats[queue].len++;
  94         ar->tx_stats[queue].count++;
  95
  96         mem_full = is_mem_full(ar);
  97         for (i = 0; i < ar->hw->queues; i++) {
  98                 if (mem_full || ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
  99                         ieee80211_stop_queue(ar->hw, i);
 100                         ar->queue_stop_timeout[i] = jiffies;
 101                 }
 102         }
 103
 104         spin_unlock_bh(&ar->tx_stats_lock);
 105 }
 106
 107 static void carl9170_tx_accounting_free(struct ar9170 *ar, struct sk_buff *skb)
 108 {
 109         struct ieee80211_tx_info *txinfo;
 110         int queue;
 111
 112         txinfo = IEEE80211_SKB_CB(skb);
 113         queue = skb_get_queue_mapping(skb);
 114
 115         spin_lock_bh(&ar->tx_stats_lock);
 116
 117         ar->tx_stats[queue].len--;
 118
 119         if (!is_mem_full(ar)) {
 120                 unsigned int i;
 121                 for (i = 0; i < ar->hw->queues; i++) {
 122                         if (ar->tx_stats[i].len >= CARL9170_NUM_TX_LIMIT_SOFT)
 123                                 continue;
 124
 125                         if (ieee80211_queue_stopped(ar->hw, i)) {
 126                                 unsigned long tmp;
 127
 128                                 tmp = jiffies - ar->queue_stop_timeout[i];
 129                                 if (tmp > ar->max_queue_stop_timeout[i])
 130                                         ar->max_queue_stop_timeout[i] = tmp;
 131                         }
 132
 133                         ieee80211_wake_queue(ar->hw, i);
 134                 }
 135         }
 136
 137         spin_unlock_bh(&ar->tx_stats_lock);
 138         if (atomic_dec_and_test(&ar->tx_total_queued))
 139                 complete(&ar->tx_flush);
 140 }
 141
 142 static int carl9170_alloc_dev_space(struct ar9170 *ar, struct sk_buff *skb)
 143 {
 144         struct _carl9170_tx_superframe *super = (void *) skb->data;
 145         unsigned int chunks;
 146         int cookie = -1;
 147
 148         atomic_inc(&ar->mem_allocs);
 149
 150         chunks = DIV_ROUND_UP(skb->len, ar->fw.mem_block_size);
 151         if (unlikely(atomic_sub_return(chunks, &ar->mem_free_blocks) < 0)) {
 152                 atomic_add(chunks, &ar->mem_free_blocks);
 153                 return -ENOSPC;
 154         }
 155
 156         spin_lock_bh(&ar->mem_lock);
 157         cookie = bitmap_find_free_region(ar->mem_bitmap, ar->fw.mem_blocks, 0);
 158         spin_unlock_bh(&ar->mem_lock);
 159
 160         if (unlikely(cookie < 0)) {
 161                 atomic_add(chunks, &ar->mem_free_blocks);
 162                 return -ENOSPC;
 163         }
 164
 165         super = (void *) skb->data;
 166
 167         /*
 168          * Cookie #0 serves two special purposes:
 169          *  1. The firmware might use it generate BlockACK frames
 170          *     in responds of an incoming BlockAckReqs.
 171          *
 172          *  2. Prevent double-free bugs.
 173          */
 174         super->s.cookie = (u8) cookie + 1;
 175         return 0;
 176 }
 177
 178 static void carl9170_release_dev_space(struct ar9170 *ar, struct sk_buff *skb)
 179 {
 180         struct _carl9170_tx_superframe *super = (void *) skb->data;
 181         int cookie;
 182
 183         /* make a local copy of the cookie */
 184         cookie = super->s.cookie;
 185         /* invalidate cookie */
 186         super->s.cookie = 0;
 187
 188         /*
 189          * Do a out-of-bounds check on the cookie:
 190          *
 191          *  * cookie "0" is reserved and won't be assigned to any
 192          *    out-going frame. Internally however, it is used to
 193          *    mark no longer/un-accounted frames and serves as a
 194          *    cheap way of preventing frames from being freed
 195          *    twice by _accident_. NB: There is a tiny race...
 196          *
 197          *  * obviously, cookie number is limited by the amount
 198          *    of available memory blocks, so the number can
 199          *    never execeed the mem_blocks count.
 200          */
 201         if (unlikely(WARN_ON_ONCE(cookie == 0) ||
 202             WARN_ON_ONCE(cookie > ar->fw.mem_blocks)))
 203                 return;
 204
 205         atomic_add(DIV_ROUND_UP(skb->len, ar->fw.mem_block_size),
 206                    &ar->mem_free_blocks);
 207
 208         spin_lock_bh(&ar->mem_lock);
 209         bitmap_release_region(ar->mem_bitmap, cookie - 1, 0);
 210         spin_unlock_bh(&ar->mem_lock);
 211 }
 212
 213 /* Called from any context */
 214 static void carl9170_tx_release(struct kref *ref)
 215 {
 216         struct ar9170 *ar;
 217         struct carl9170_tx_info *arinfo;
 218         struct ieee80211_tx_info *txinfo;
 219         struct sk_buff *skb;
 220
 221         arinfo = container_of(ref, struct carl9170_tx_info, ref);
 222         txinfo = container_of((void *) arinfo, struct ieee80211_tx_info,
 223                               rate_driver_data);
 224         skb = container_of((void *) txinfo, struct sk_buff, cb);
 225
 226         ar = arinfo->ar;
 227         if (WARN_ON_ONCE(!ar))
 228                 return;
 229
 230         BUILD_BUG_ON(
 231             offsetof(struct ieee80211_tx_info, status.ampdu_ack_len) != 23);
 232
 233         memset(&txinfo->status.ampdu_ack_len, 0,
 234                sizeof(struct ieee80211_tx_info) -
 235                offsetof(struct ieee80211_tx_info, status.ampdu_ack_len));
 236
 237         if (atomic_read(&ar->tx_total_queued))
 238                 ar->tx_schedule = true;
 239
 240         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU) {
 241                 if (!atomic_read(&ar->tx_ampdu_upload))
 242                         ar->tx_ampdu_schedule = true;
 243
 244                 if (txinfo->flags & IEEE80211_TX_STAT_AMPDU) {
 245                         struct _carl9170_tx_superframe *super;
 246
 247                         super = (void *)skb->data;
 248                         txinfo->status.ampdu_len = super->s.rix;
 249                         txinfo->status.ampdu_ack_len = super->s.cnt;
 250                 } else if (txinfo->flags & IEEE80211_TX_STAT_ACK) {
 251                         /*
 252                          * drop redundant tx_status reports:
 253                          *
 254                          * 1. ampdu_ack_len of the final tx_status does
 255                          *    include the feedback of this particular frame.
 256                          *
 257                          * 2. tx_status_irqsafe only queues up to 128
 258                          *    tx feedback reports and discards the rest.
 259                          *
 260                          * 3. minstrel_ht is picky, it only accepts
 261                          *    reports of frames with the TX_STATUS_AMPDU flag.
 262                          */
 263
 264                         dev_kfree_skb_any(skb);
 265                         return;
 266                 } else {
 267                         /*
 268                          * Frame has failed, but we want to keep it in
 269                          * case it was lost due to a power-state
 270                          * transition.
 271                          */
 272                 }
 273         }
 274
 275         skb_pull(skb, sizeof(struct _carl9170_tx_superframe));
 276         ieee80211_tx_status_irqsafe(ar->hw, skb);
 277 }
 278
 279 void carl9170_tx_get_skb(struct sk_buff *skb)
 280 {
 281         struct carl9170_tx_info *arinfo = (void *)
 282                 (IEEE80211_SKB_CB(skb))->rate_driver_data;
 283         kref_get(&arinfo->ref);
 284 }
 285
 286 int carl9170_tx_put_skb(struct sk_buff *skb)
 287 {
 288         struct carl9170_tx_info *arinfo = (void *)
 289                 (IEEE80211_SKB_CB(skb))->rate_driver_data;
 290
 291         return kref_put(&arinfo->ref, carl9170_tx_release);
 292 }
 293
 294 /* Caller must hold the tid_info->lock & rcu_read_lock */
 295 static void carl9170_tx_shift_bm(struct ar9170 *ar,
 296         struct carl9170_sta_tid *tid_info, u16 seq)
 297 {
 298         u16 off;
 299
 300         off = SEQ_DIFF(seq, tid_info->bsn);
 301
 302         if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
 303                 return;
 304
 305         /*
 306          * Sanity check. For each MPDU we set the bit in bitmap and
 307          * clear it once we received the tx_status.
 308          * But if the bit is already cleared then we've been bitten
 309          * by a bug.
 310          */
 311         WARN_ON_ONCE(!test_and_clear_bit(off, tid_info->bitmap));
 312
 313         off = SEQ_DIFF(tid_info->snx, tid_info->bsn);
 314         if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
 315                 return;
 316
 317         if (!bitmap_empty(tid_info->bitmap, off))
 318                 off = find_first_bit(tid_info->bitmap, off);
 319
 320         tid_info->bsn += off;
 321         tid_info->bsn &= 0x0fff;
 322
 323         bitmap_shift_right(tid_info->bitmap, tid_info->bitmap,
 324                            off, CARL9170_BAW_BITS);
 325 }
 326
 327 static void carl9170_tx_status_process_ampdu(struct ar9170 *ar,
 328         struct sk_buff *skb, struct ieee80211_tx_info *txinfo)
 329 {
 330         struct _carl9170_tx_superframe *super = (void *) skb->data;
 331         struct ieee80211_hdr *hdr = (void *) super->frame_data;
 332         struct ieee80211_tx_info *tx_info;
 333         struct carl9170_tx_info *ar_info;
 334         struct carl9170_sta_info *sta_info;
 335         struct ieee80211_sta *sta;
 336         struct carl9170_sta_tid *tid_info;
 337         struct ieee80211_vif *vif;
 338         unsigned int vif_id;
 339         u8 tid;
 340
 341         if (!(txinfo->flags & IEEE80211_TX_CTL_AMPDU) ||
 342             txinfo->flags & IEEE80211_TX_CTL_INJECTED ||
 343            (!(super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_AGGR))))
 344                 return;
 345
 346         tx_info = IEEE80211_SKB_CB(skb);
 347         ar_info = (void *) tx_info->rate_driver_data;
 348
 349         vif_id = (super->s.misc & CARL9170_TX_SUPER_MISC_VIF_ID) >>
 350                  CARL9170_TX_SUPER_MISC_VIF_ID_S;
 351
 352         if (WARN_ON_ONCE(vif_id >= AR9170_MAX_VIRTUAL_MAC))
 353                 return;
 354
 355         rcu_read_lock();
 356         vif = rcu_dereference(ar->vif_priv[vif_id].vif);
 357         if (unlikely(!vif))
 358                 goto out_rcu;
 359
 360         /*
 361          * Normally we should use wrappers like ieee80211_get_DA to get
 362          * the correct peer ieee80211_sta.
 363          *
 364          * But there is a problem with indirect traffic (broadcasts, or
 365          * data which is designated for other stations) in station mode.
 366          * The frame will be directed to the AP for distribution and not
 367          * to the actual destination.
 368          */
 369         sta = ieee80211_find_sta(vif, hdr->addr1);
 370         if (unlikely(!sta))
 371                 goto out_rcu;
 372
 373         tid = get_tid_h(hdr);
 374
 375         sta_info = (void *) sta->drv_priv;
 376         tid_info = rcu_dereference(sta_info->agg[tid]);
 377         if (!tid_info)
 378                 goto out_rcu;
 379
 380         spin_lock_bh(&tid_info->lock);
 381         if (likely(tid_info->state >= CARL9170_TID_STATE_IDLE))
 382                 carl9170_tx_shift_bm(ar, tid_info, get_seq_h(hdr));
 383
 384         if (sta_info->stats[tid].clear) {
 385                 sta_info->stats[tid].clear = false;
 386                 sta_info->stats[tid].req = false;
 387                 sta_info->stats[tid].ampdu_len = 0;
 388                 sta_info->stats[tid].ampdu_ack_len = 0;
 389         }
 390
 391         sta_info->stats[tid].ampdu_len++;
 392         if (txinfo->status.rates[0].count == 1)
 393                 sta_info->stats[tid].ampdu_ack_len++;
 394
 395         if (!(txinfo->flags & IEEE80211_TX_STAT_ACK))
 396                 sta_info->stats[tid].req = true;
 397
 398         if (super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_IMM_BA)) {
 399                 super->s.rix = sta_info->stats[tid].ampdu_len;
 400                 super->s.cnt = sta_info->stats[tid].ampdu_ack_len;
 401                 txinfo->flags |= IEEE80211_TX_STAT_AMPDU;
 402                 if (sta_info->stats[tid].req)
 403                         txinfo->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
 404
 405                 sta_info->stats[tid].clear = true;
 406         }
 407         spin_unlock_bh(&tid_info->lock);
 408
 409 out_rcu:
 410         rcu_read_unlock();
 411 }
 412
 413 void carl9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
 414                         const bool success)
 415 {
 416         struct ieee80211_tx_info *txinfo;
 417
 418         carl9170_tx_accounting_free(ar, skb);
 419
 420         txinfo = IEEE80211_SKB_CB(skb);
 421
 422         if (success)
 423                 txinfo->flags |= IEEE80211_TX_STAT_ACK;
 424         else
 425                 ar->tx_ack_failures++;
 426
 427         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
 428                 carl9170_tx_status_process_ampdu(ar, skb, txinfo);
 429
 430         carl9170_tx_put_skb(skb);
 431 }
 432
 433 /* This function may be called form any context */
 434 void carl9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
 435 {
 436         struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
 437
 438         atomic_dec(&ar->tx_total_pending);
 439
 440         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
 441                 atomic_dec(&ar->tx_ampdu_upload);
 442
 443         if (carl9170_tx_put_skb(skb))
 444                 tasklet_hi_schedule(&ar->usb_tasklet);
 445 }
 446
 447 static struct sk_buff *carl9170_get_queued_skb(struct ar9170 *ar, u8 cookie,
 448                                                struct sk_buff_head *queue)
 449 {
 450         struct sk_buff *skb;
 451
 452         spin_lock_bh(&queue->lock);
 453         skb_queue_walk(queue, skb) {
 454                 struct _carl9170_tx_superframe *txc = (void *) skb->data;
 455
 456                 if (txc->s.cookie != cookie)
 457                         continue;
 458
 459                 __skb_unlink(skb, queue);
 460                 spin_unlock_bh(&queue->lock);
 461
 462                 carl9170_release_dev_space(ar, skb);
 463                 return skb;
 464         }
 465         spin_unlock_bh(&queue->lock);
 466
 467         return NULL;
 468 }
 469
 470 static void carl9170_tx_fill_rateinfo(struct ar9170 *ar, unsigned int rix,
 471         unsigned int tries, struct ieee80211_tx_info *txinfo)
 472 {
 473         unsigned int i;
 474
 475         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 476                 if (txinfo->status.rates[i].idx < 0)
 477                         break;
 478
 479                 if (i == rix) {
 480                         txinfo->status.rates[i].count = tries;
 481                         i++;
 482                         break;
 483                 }
 484         }
 485
 486         for (; i < IEEE80211_TX_MAX_RATES; i++) {
 487                 txinfo->status.rates[i].idx = -1;
 488                 txinfo->status.rates[i].count = 0;
 489         }
 490 }
 491
 492 static void carl9170_check_queue_stop_timeout(struct ar9170 *ar)
 493 {
 494         int i;
 495         struct sk_buff *skb;
 496         struct ieee80211_tx_info *txinfo;
 497         struct carl9170_tx_info *arinfo;
 498         bool restart = false;
 499
 500         for (i = 0; i < ar->hw->queues; i++) {
 501                 spin_lock_bh(&ar->tx_status[i].lock);
 502
 503                 skb = skb_peek(&ar->tx_status[i]);
 504
 505                 if (!skb)
 506                         goto next;
 507
 508                 txinfo = IEEE80211_SKB_CB(skb);
 509                 arinfo = (void *) txinfo->rate_driver_data;
 510
 511                 if (time_is_before_jiffies(arinfo->timeout +
 512                     msecs_to_jiffies(CARL9170_QUEUE_STUCK_TIMEOUT)) == true)
 513                         restart = true;
 514
 515 next:
 516                 spin_unlock_bh(&ar->tx_status[i].lock);
 517         }
 518
 519         if (restart) {
 520                 /*
 521                  * At least one queue has been stuck for long enough.
 522                  * Give the device a kick and hope it gets back to
 523                  * work.
 524                  *
 525                  * possible reasons may include:
 526                  *  - frames got lost/corrupted (bad connection to the device)
 527                  *  - stalled rx processing/usb controller hiccups
 528                  *  - firmware errors/bugs
 529                  *  - every bug you can think of.
 530                  *  - all bugs you can't...
 531                  *  - ...
 532                  */
 533                 carl9170_restart(ar, CARL9170_RR_STUCK_TX);
 534         }
 535 }
 536
 537 static void carl9170_tx_ampdu_timeout(struct ar9170 *ar)
 538 {
 539         struct carl9170_sta_tid *iter;
 540         struct sk_buff *skb;
 541         struct ieee80211_tx_info *txinfo;
 542         struct carl9170_tx_info *arinfo;
 543         struct _carl9170_tx_superframe *super;
 544         struct ieee80211_sta *sta;
 545         struct ieee80211_vif *vif;
 546         struct ieee80211_hdr *hdr;
 547         unsigned int vif_id;
 548
 549         rcu_read_lock();
 550         list_for_each_entry_rcu(iter, &ar->tx_ampdu_list, list) {
 551                 if (iter->state < CARL9170_TID_STATE_IDLE)
 552                         continue;
 553
 554                 spin_lock_bh(&iter->lock);
 555                 skb = skb_peek(&iter->queue);
 556                 if (!skb)
 557                         goto unlock;
 558
 559                 txinfo = IEEE80211_SKB_CB(skb);
 560                 arinfo = (void *)txinfo->rate_driver_data;
 561                 if (time_is_after_jiffies(arinfo->timeout +
 562                     msecs_to_jiffies(CARL9170_QUEUE_TIMEOUT)))
 563                         goto unlock;
 564
 565                 super = (void *) skb->data;
 566                 hdr = (void *) super->frame_data;
 567
 568                 vif_id = (super->s.misc & CARL9170_TX_SUPER_MISC_VIF_ID) >>
 569                          CARL9170_TX_SUPER_MISC_VIF_ID_S;
 570
 571                 if (WARN_ON(vif_id >= AR9170_MAX_VIRTUAL_MAC))
 572                         goto unlock;
 573
 574                 vif = rcu_dereference(ar->vif_priv[vif_id].vif);
 575                 if (WARN_ON(!vif))
 576                         goto unlock;
 577
 578                 sta = ieee80211_find_sta(vif, hdr->addr1);
 579                 if (WARN_ON(!sta))
 580                         goto unlock;
 581
 582                 ieee80211_stop_tx_ba_session(sta, iter->tid);
 583 unlock:
 584                 spin_unlock_bh(&iter->lock);
 585
 586         }
 587         rcu_read_unlock();
 588 }
 589
 590 void carl9170_tx_janitor(struct work_struct *work)
 591 {
 592         struct ar9170 *ar = container_of(work, struct ar9170,
 593                                          tx_janitor.work);
 594         if (!IS_STARTED(ar))
 595                 return;
 596
 597         ar->tx_janitor_last_run = jiffies;
 598
 599         carl9170_check_queue_stop_timeout(ar);
 600         carl9170_tx_ampdu_timeout(ar);
 601
 602         if (!atomic_read(&ar->tx_total_queued))
 603                 return;
 604
 605         ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
 606                 msecs_to_jiffies(CARL9170_TX_TIMEOUT));
 607 }
 608
 609 static void __carl9170_tx_process_status(struct ar9170 *ar,
 610         const uint8_t cookie, const uint8_t info)
 611 {
 612         struct sk_buff *skb;
 613         struct ieee80211_tx_info *txinfo;
 614         struct carl9170_tx_info *arinfo;
 615         unsigned int r, t, q;
 616         bool success = true;
 617
 618         q = ar9170_qmap[info & CARL9170_TX_STATUS_QUEUE];
 619
 620         skb = carl9170_get_queued_skb(ar, cookie, &ar->tx_status[q]);
 621         if (!skb) {
 622                 /*
 623                  * We have lost the race to another thread.
 624                  */
 625
 626                 return ;
 627         }
 628
 629         txinfo = IEEE80211_SKB_CB(skb);
 630         arinfo = (void *) txinfo->rate_driver_data;
 631
 632         if (!(info & CARL9170_TX_STATUS_SUCCESS))
 633                 success = false;
 634
 635         r = (info & CARL9170_TX_STATUS_RIX) >> CARL9170_TX_STATUS_RIX_S;
 636         t = (info & CARL9170_TX_STATUS_TRIES) >> CARL9170_TX_STATUS_TRIES_S;
 637
 638         carl9170_tx_fill_rateinfo(ar, r, t, txinfo);
 639         carl9170_tx_status(ar, skb, success);
 640 }
 641
 642 void carl9170_tx_process_status(struct ar9170 *ar,
 643                                 const struct carl9170_rsp *cmd)
 644 {
 645         unsigned int i;
 646
 647         for (i = 0;  i < cmd->hdr.ext; i++) {
 648                 if (WARN_ON(i > ((cmd->hdr.len / 2) + 1))) {
 649                         print_hex_dump_bytes("UU:", DUMP_PREFIX_NONE,
 650                                              (void *) cmd, cmd->hdr.len + 4);
 651                         break;
 652                 }
 653
 654                 __carl9170_tx_process_status(ar, cmd->_tx_status[i].cookie,
 655                                              cmd->_tx_status[i].info);
 656         }
 657 }
 658
 659 static __le32 carl9170_tx_physet(struct ar9170 *ar,
 660         struct ieee80211_tx_info *info, struct ieee80211_tx_rate *txrate)
 661 {
 662         struct ieee80211_rate *rate = NULL;
 663         u32 power, chains;
 664         __le32 tmp;
 665
 666         tmp = cpu_to_le32(0);
 667
 668         if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 669                 tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ <<
 670                         AR9170_TX_PHY_BW_S);
 671         /* this works because 40 MHz is 2 and dup is 3 */
 672         if (txrate->flags & IEEE80211_TX_RC_DUP_DATA)
 673                 tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ_DUP <<
 674                         AR9170_TX_PHY_BW_S);
 675
 676         if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
 677                 tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_GI);
 678
 679         if (txrate->flags & IEEE80211_TX_RC_MCS) {
 680                 u32 r = txrate->idx;
 681                 u8 *txpower;
 682
 683                 /* heavy clip control */
 684                 tmp |= cpu_to_le32((r & 0x7) <<
 685                         AR9170_TX_PHY_TX_HEAVY_CLIP_S);
 686
 687                 if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
 688                         if (info->band == IEEE80211_BAND_5GHZ)
 689                                 txpower = ar->power_5G_ht40;
 690                         else
 691                                 txpower = ar->power_2G_ht40;
 692                 } else {
 693                         if (info->band == IEEE80211_BAND_5GHZ)
 694                                 txpower = ar->power_5G_ht20;
 695                         else
 696                                 txpower = ar->power_2G_ht20;
 697                 }
 698
 699                 power = txpower[r & 7];
 700
 701                 /* +1 dBm for HT40 */
 702                 if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 703                         power += 2;
 704
 705                 r <<= AR9170_TX_PHY_MCS_S;
 706                 BUG_ON(r & ~AR9170_TX_PHY_MCS);
 707
 708                 tmp |= cpu_to_le32(r & AR9170_TX_PHY_MCS);
 709                 tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);
 710
 711                 /*
 712                  * green field preamble does not work.
 713                  *
 714                  * if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
 715                  * tmp |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);
 716                  */
 717         } else {
 718                 u8 *txpower;
 719                 u32 mod;
 720                 u32 phyrate;
 721                 u8 idx = txrate->idx;
 722
 723                 if (info->band != IEEE80211_BAND_2GHZ) {
 724                         idx += 4;
 725                         txpower = ar->power_5G_leg;
 726                         mod = AR9170_TX_PHY_MOD_OFDM;
 727                 } else {
 728                         if (idx < 4) {
 729                                 txpower = ar->power_2G_cck;
 730                                 mod = AR9170_TX_PHY_MOD_CCK;
 731                         } else {
 732                                 mod = AR9170_TX_PHY_MOD_OFDM;
 733                                 txpower = ar->power_2G_ofdm;
 734                         }
 735                 }
 736
 737                 rate = &__carl9170_ratetable[idx];
 738
 739                 phyrate = rate->hw_value & 0xF;
 740                 power = txpower[(rate->hw_value & 0x30) >> 4];
 741                 phyrate <<= AR9170_TX_PHY_MCS_S;
 742
 743                 tmp |= cpu_to_le32(mod);
 744                 tmp |= cpu_to_le32(phyrate);
 745
 746                 /*
 747                  * short preamble seems to be broken too.
 748                  *
 749                  * if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
 750                  *      tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_PREAMBLE);
 751                  */
 752         }
 753         power <<= AR9170_TX_PHY_TX_PWR_S;
 754         power &= AR9170_TX_PHY_TX_PWR;
 755         tmp |= cpu_to_le32(power);
 756
 757         /* set TX chains */
 758         if (ar->eeprom.tx_mask == 1) {
 759                 chains = AR9170_TX_PHY_TXCHAIN_1;
 760         } else {
 761                 chains = AR9170_TX_PHY_TXCHAIN_2;
 762
 763                 /* >= 36M legacy OFDM - use only one chain */
 764                 if (rate && rate->bitrate >= 360 &&
 765                     !(txrate->flags & IEEE80211_TX_RC_MCS))
 766                         chains = AR9170_TX_PHY_TXCHAIN_1;
 767         }
 768         tmp |= cpu_to_le32(chains << AR9170_TX_PHY_TXCHAIN_S);
 769
 770         return tmp;
 771 }
 772
 773 static bool carl9170_tx_rts_check(struct ar9170 *ar,
 774                                   struct ieee80211_tx_rate *rate,
 775                                   bool ampdu, bool multi)
 776 {
 777         switch (ar->erp_mode) {
 778         case CARL9170_ERP_AUTO:
 779                 if (ampdu)
 780                         break;
 781
 782         case CARL9170_ERP_MAC80211:
 783                 if (!(rate->flags & IEEE80211_TX_RC_USE_RTS_CTS))
 784                         break;
 785
 786         case CARL9170_ERP_RTS:
 787                 if (likely(!multi))
 788                         return true;
 789
 790         default:
 791                 break;
 792         }
 793
 794         return false;
 795 }
 796
 797 static bool carl9170_tx_cts_check(struct ar9170 *ar,
 798                                   struct ieee80211_tx_rate *rate)
 799 {
 800         switch (ar->erp_mode) {
 801         case CARL9170_ERP_AUTO:
 802         case CARL9170_ERP_MAC80211:
 803                 if (!(rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
 804                         break;
 805
 806         case CARL9170_ERP_CTS:
 807                 return true;
 808
 809         default:
 810                 break;
 811         }
 812
 813         return false;
 814 }
 815
 816 static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
 817 {
 818         struct ieee80211_hdr *hdr;
 819         struct _carl9170_tx_superframe *txc;
 820         struct carl9170_vif_info *cvif;
 821         struct ieee80211_tx_info *info;
 822         struct ieee80211_tx_rate *txrate;
 823         struct ieee80211_sta *sta;
 824         struct carl9170_tx_info *arinfo;
 825         unsigned int hw_queue;
 826         int i;
 827         __le16 mac_tmp;
 828         u16 len;
 829         bool ampdu, no_ack;
 830
 831         BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
 832         BUILD_BUG_ON(sizeof(struct _carl9170_tx_superdesc) !=
 833                      CARL9170_TX_SUPERDESC_LEN);
 834
 835         BUILD_BUG_ON(sizeof(struct _ar9170_tx_hwdesc) !=
 836                      AR9170_TX_HWDESC_LEN);
 837
 838         BUILD_BUG_ON(IEEE80211_TX_MAX_RATES < CARL9170_TX_MAX_RATES);
 839
 840         BUILD_BUG_ON(AR9170_MAX_VIRTUAL_MAC >
 841                 ((CARL9170_TX_SUPER_MISC_VIF_ID >>
 842                  CARL9170_TX_SUPER_MISC_VIF_ID_S) + 1));
 843
 844         hw_queue = ar9170_qmap[carl9170_get_queue(ar, skb)];
 845
 846         hdr = (void *)skb->data;
 847         info = IEEE80211_SKB_CB(skb);
 848         len = skb->len;
 849
 850         /*
 851          * Note: If the frame was sent through a monitor interface,
 852          * the ieee80211_vif pointer can be NULL.
 853          */
 854         if (likely(info->control.vif))
 855                 cvif = (void *) info->control.vif->drv_priv;
 856         else
 857                 cvif = NULL;
 858
 859         sta = info->control.sta;
 860
 861         txc = (void *)skb_push(skb, sizeof(*txc));
 862         memset(txc, 0, sizeof(*txc));
 863
 864         SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, txc->s.misc, hw_queue);
 865
 866         if (likely(cvif))
 867                 SET_VAL(CARL9170_TX_SUPER_MISC_VIF_ID, txc->s.misc, cvif->id);
 868
 869         if (unlikely(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM))
 870                 txc->s.misc |= CARL9170_TX_SUPER_MISC_CAB;
 871
 872         if (unlikely(info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ))
 873                 txc->s.misc |= CARL9170_TX_SUPER_MISC_ASSIGN_SEQ;
 874
 875         if (unlikely(ieee80211_is_probe_resp(hdr->frame_control)))
 876                 txc->s.misc |= CARL9170_TX_SUPER_MISC_FILL_IN_TSF;
 877
 878         mac_tmp = cpu_to_le16(AR9170_TX_MAC_HW_DURATION |
 879                               AR9170_TX_MAC_BACKOFF);
 880         mac_tmp |= cpu_to_le16((hw_queue << AR9170_TX_MAC_QOS_S) &
 881                                AR9170_TX_MAC_QOS);
 882
 883         no_ack = !!(info->flags & IEEE80211_TX_CTL_NO_ACK);
 884         if (unlikely(no_ack))
 885                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);
 886
 887         if (info->control.hw_key) {
 888                 len += info->control.hw_key->icv_len;
 889
 890                 switch (info->control.hw_key->cipher) {
 891                 case WLAN_CIPHER_SUITE_WEP40:
 892                 case WLAN_CIPHER_SUITE_WEP104:
 893                 case WLAN_CIPHER_SUITE_TKIP:
 894                         mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_RC4);
 895                         break;
 896                 case WLAN_CIPHER_SUITE_CCMP:
 897                         mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_AES);
 898                         break;
 899                 default:
 900                         WARN_ON(1);
 901                         goto err_out;
 902                 }
 903         }
 904
 905         ampdu = !!(info->flags & IEEE80211_TX_CTL_AMPDU);
 906         if (ampdu) {
 907                 unsigned int density, factor;
 908
 909                 if (unlikely(!sta || !cvif))
 910                         goto err_out;
 911
 912                 factor = min_t(unsigned int, 1u, sta->ht_cap.ampdu_factor);
 913                 density = sta->ht_cap.ampdu_density;
 914
 915                 if (density) {
 916                         /*
 917                          * Watch out!
 918                          *
 919                          * Otus uses slightly different density values than
 920                          * those from the 802.11n spec.
 921                          */
 922
 923                         density = max_t(unsigned int, density + 1, 7u);
 924                 }
 925
 926                 SET_VAL(CARL9170_TX_SUPER_AMPDU_DENSITY,
 927                         txc->s.ampdu_settings, density);
 928
 929                 SET_VAL(CARL9170_TX_SUPER_AMPDU_FACTOR,
 930                         txc->s.ampdu_settings, factor);
 931
 932                 for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
 933                         txrate = &info->control.rates[i];
 934                         if (txrate->idx >= 0) {
 935                                 txc->s.ri[i] =
 936                                         CARL9170_TX_SUPER_RI_AMPDU;
 937
 938                                 if (WARN_ON(!(txrate->flags &
 939                                               IEEE80211_TX_RC_MCS))) {
 940                                         /*
 941                                          * Not sure if it's even possible
 942                                          * to aggregate non-ht rates with
 943                                          * this HW.
 944                                          */
 945                                         goto err_out;
 946                                 }
 947                                 continue;
 948                         }
 949
 950                         txrate->idx = 0;
 951                         txrate->count = ar->hw->max_rate_tries;
 952                 }
 953
 954                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
 955         }
 956
 957         /*
 958          * NOTE: For the first rate, the ERP & AMPDU flags are directly
 959          * taken from mac_control. For all fallback rate, the firmware
 960          * updates the mac_control flags from the rate info field.
 961          */
 962         for (i = 1; i < CARL9170_TX_MAX_RATES; i++) {
 963                 txrate = &info->control.rates[i];
 964                 if (txrate->idx < 0)
 965                         break;
 966
 967                 SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[i],
 968                         txrate->count);
 969
 970                 if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
 971                         txc->s.ri[i] |= (AR9170_TX_MAC_PROT_RTS <<
 972                                 CARL9170_TX_SUPER_RI_ERP_PROT_S);
 973                 else if (carl9170_tx_cts_check(ar, txrate))
 974                         txc->s.ri[i] |= (AR9170_TX_MAC_PROT_CTS <<
 975                                 CARL9170_TX_SUPER_RI_ERP_PROT_S);
 976
 977                 txc->s.rr[i - 1] = carl9170_tx_physet(ar, info, txrate);
 978         }
 979
 980         txrate = &info->control.rates[0];
 981         SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[0], txrate->count);
 982
 983         if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
 984                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
 985         else if (carl9170_tx_cts_check(ar, txrate))
 986                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
 987
 988         txc->s.len = cpu_to_le16(skb->len);
 989         txc->f.length = cpu_to_le16(len + FCS_LEN);
 990         txc->f.mac_control = mac_tmp;
 991         txc->f.phy_control = carl9170_tx_physet(ar, info, txrate);
 992
 993         arinfo = (void *)info->rate_driver_data;
 994         arinfo->timeout = jiffies;
 995         arinfo->ar = ar;
 996         kref_init(&arinfo->ref);
 997         return 0;
 998
 999 err_out:
1000         skb_pull(skb, sizeof(*txc));
1001         return -EINVAL;
1002 }
1003
1004 static void carl9170_set_immba(struct ar9170 *ar, struct sk_buff *skb)
1005 {
1006         struct _carl9170_tx_superframe *super;
1007
1008         super = (void *) skb->data;
1009         super->f.mac_control |= cpu_to_le16(AR9170_TX_MAC_IMM_BA);
1010 }
1011
1012 static void carl9170_set_ampdu_params(struct ar9170 *ar, struct sk_buff *skb)
1013 {
1014         struct _carl9170_tx_superframe *super;
1015         int tmp;
1016
1017         super = (void *) skb->data;
1018
1019         tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_DENSITY) <<
1020                 CARL9170_TX_SUPER_AMPDU_DENSITY_S;
1021
1022         /*
1023          * If you haven't noticed carl9170_tx_prepare has already filled
1024          * in all ampdu spacing & factor parameters.
1025          * Now it's the time to check whenever the settings have to be
1026          * updated by the firmware, or if everything is still the same.
1027          *
1028          * There's no sane way to handle different density values with
1029          * this hardware, so we may as well just do the compare in the
1030          * driver.
1031          */
1032
1033         if (tmp != ar->current_density) {
1034                 ar->current_density = tmp;
1035                 super->s.ampdu_settings |=
1036                         CARL9170_TX_SUPER_AMPDU_COMMIT_DENSITY;
1037         }
1038
1039         tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_FACTOR) <<
1040                 CARL9170_TX_SUPER_AMPDU_FACTOR_S;
1041
1042         if (tmp != ar->current_factor) {
1043                 ar->current_factor = tmp;
1044                 super->s.ampdu_settings |=
1045                         CARL9170_TX_SUPER_AMPDU_COMMIT_FACTOR;
1046         }
1047 }
1048
1049 static bool carl9170_tx_rate_check(struct ar9170 *ar, struct sk_buff *_dest,
1050                                    struct sk_buff *_src)
1051 {
1052         struct _carl9170_tx_superframe *dest, *src;
1053
1054         dest = (void *) _dest->data;
1055         src = (void *) _src->data;
1056
1057         /*
1058          * The mac80211 rate control algorithm expects that all MPDUs in
1059          * an AMPDU share the same tx vectors.
1060          * This is not really obvious right now, because the hardware
1061          * does the AMPDU setup according to its own rulebook.
1062          * Our nicely assembled, strictly monotonic increasing mpdu
1063          * chains will be broken up, mashed back together...
1064          */
1065
1066         return (dest->f.phy_control == src->f.phy_control);
1067 }
1068
1069 static void carl9170_tx_ampdu(struct ar9170 *ar)
1070 {
1071         struct sk_buff_head agg;
1072         struct carl9170_sta_tid *tid_info;
1073         struct sk_buff *skb, *first;
1074         unsigned int i = 0, done_ampdus = 0;
1075         u16 seq, queue, tmpssn;
1076
1077         atomic_inc(&ar->tx_ampdu_scheduler);
1078         ar->tx_ampdu_schedule = false;
1079
1080         if (atomic_read(&ar->tx_ampdu_upload))
1081                 return;
1082
1083         if (!ar->tx_ampdu_list_len)
1084                 return;
1085
1086         __skb_queue_head_init(&agg);
1087
1088         rcu_read_lock();
1089         tid_info = rcu_dereference(ar->tx_ampdu_iter);
1090         if (WARN_ON_ONCE(!tid_info)) {
1091                 rcu_read_unlock();
1092                 return;
1093         }
1094
1095 retry:
1096         list_for_each_entry_continue_rcu(tid_info, &ar->tx_ampdu_list, list) {
1097                 i++;
1098
1099                 if (tid_info->state < CARL9170_TID_STATE_PROGRESS)
1100                         continue;
1101
1102                 queue = TID_TO_WME_AC(tid_info->tid);
1103
1104                 spin_lock_bh(&tid_info->lock);
1105                 if (tid_info->state != CARL9170_TID_STATE_XMIT)
1106                         goto processed;
1107
1108                 tid_info->counter++;
1109                 first = skb_peek(&tid_info->queue);
1110                 tmpssn = carl9170_get_seq(first);
1111                 seq = tid_info->snx;
1112
1113                 if (unlikely(tmpssn != seq)) {
1114                         tid_info->state = CARL9170_TID_STATE_IDLE;
1115
1116                         goto processed;
1117                 }
1118
1119                 while ((skb = skb_peek(&tid_info->queue))) {
1120                         /* strict 0, 1, ..., n - 1, n frame sequence order */
1121                         if (unlikely(carl9170_get_seq(skb) != seq))
1122                                 break;
1123
1124                         /* don't upload more than AMPDU FACTOR allows. */
1125                         if (unlikely(SEQ_DIFF(tid_info->snx, tid_info->bsn) >=
1126                             (tid_info->max - 1)))
1127                                 break;
1128
1129                         if (!carl9170_tx_rate_check(ar, skb, first))
1130                                 break;
1131
1132                         atomic_inc(&ar->tx_ampdu_upload);
1133                         tid_info->snx = seq = SEQ_NEXT(seq);
1134                         __skb_unlink(skb, &tid_info->queue);
1135
1136                         __skb_queue_tail(&agg, skb);
1137
1138                         if (skb_queue_len(&agg) >= CARL9170_NUM_TX_AGG_MAX)
1139                                 break;
1140                 }
1141
1142                 if (skb_queue_empty(&tid_info->queue) ||
1143                     carl9170_get_seq(skb_peek(&tid_info->queue)) !=
1144                     tid_info->snx) {
1145                         /*
1146                          * stop TID, if A-MPDU frames are still missing,
1147                          * or whenever the queue is empty.
1148                          */
1149
1150                         tid_info->state = CARL9170_TID_STATE_IDLE;
1151                 }
1152                 done_ampdus++;
1153
1154 processed:
1155                 spin_unlock_bh(&tid_info->lock);
1156
1157                 if (skb_queue_empty(&agg))
1158                         continue;
1159
1160                 /* apply ampdu spacing & factor settings */
1161                 carl9170_set_ampdu_params(ar, skb_peek(&agg));
1162
1163                 /* set aggregation push bit */
1164                 carl9170_set_immba(ar, skb_peek_tail(&agg));
1165
1166                 spin_lock_bh(&ar->tx_pending[queue].lock);
1167                 skb_queue_splice_tail_init(&agg, &ar->tx_pending[queue]);
1168                 spin_unlock_bh(&ar->tx_pending[queue].lock);
1169                 ar->tx_schedule = true;
1170         }
1171         if ((done_ampdus++ == 0) && (i++ == 0))
1172                 goto retry;
1173
1174         rcu_assign_pointer(ar->tx_ampdu_iter, tid_info);
1175         rcu_read_unlock();
1176 }
1177
1178 static struct sk_buff *carl9170_tx_pick_skb(struct ar9170 *ar,
1179                                             struct sk_buff_head *queue)
1180 {
1181         struct sk_buff *skb;
1182         struct ieee80211_tx_info *info;
1183         struct carl9170_tx_info *arinfo;
1184
1185         BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
1186
1187         spin_lock_bh(&queue->lock);
1188         skb = skb_peek(queue);
1189         if (unlikely(!skb))
1190                 goto err_unlock;
1191
1192         if (carl9170_alloc_dev_space(ar, skb))
1193                 goto err_unlock;
1194
1195         __skb_unlink(skb, queue);
1196         spin_unlock_bh(&queue->lock);
1197
1198         info = IEEE80211_SKB_CB(skb);
1199         arinfo = (void *) info->rate_driver_data;
1200
1201         arinfo->timeout = jiffies;
1202
1203         /*
1204          * increase ref count to "2".
1205          * Ref counting is the easiest way to solve the race between
1206          * the the urb's completion routine: carl9170_tx_callback and
1207          * wlan tx status functions: carl9170_tx_status/janitor.
1208          */
1209         carl9170_tx_get_skb(skb);
1210
1211         return skb;
1212
1213 err_unlock:
1214         spin_unlock_bh(&queue->lock);
1215         return NULL;
1216 }
1217
1218 void carl9170_tx_drop(struct ar9170 *ar, struct sk_buff *skb)
1219 {
1220         struct _carl9170_tx_superframe *super;
1221         uint8_t q = 0;
1222
1223         ar->tx_dropped++;
1224
1225         super = (void *)skb->data;
1226         SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, q,
1227                 ar9170_qmap[carl9170_get_queue(ar, skb)]);
1228         __carl9170_tx_process_status(ar, super->s.cookie, q);
1229 }
1230
1231 static void carl9170_tx(struct ar9170 *ar)
1232 {
1233         struct sk_buff *skb;
1234         unsigned int i, q;
1235         bool schedule_garbagecollector = false;
1236
1237         ar->tx_schedule = false;
1238
1239         if (unlikely(!IS_STARTED(ar)))
1240                 return;
1241
1242         carl9170_usb_handle_tx_err(ar);
1243
1244         for (i = 0; i < ar->hw->queues; i++) {
1245                 while (!skb_queue_empty(&ar->tx_pending[i])) {
1246                         skb = carl9170_tx_pick_skb(ar, &ar->tx_pending[i]);
1247                         if (unlikely(!skb))
1248                                 break;
1249
1250                         atomic_inc(&ar->tx_total_pending);
1251
1252                         q = __carl9170_get_queue(ar, i);
1253                         /*
1254                          * NB: tx_status[i] vs. tx_status[q],
1255                          * TODO: Move into pick_skb or alloc_dev_space.
1256                          */
1257                         skb_queue_tail(&ar->tx_status[q], skb);
1258
1259                         carl9170_usb_tx(ar, skb);
1260                         schedule_garbagecollector = true;
1261                 }
1262         }
1263
1264         if (!schedule_garbagecollector)
1265                 return;
1266
1267         ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
1268                 msecs_to_jiffies(CARL9170_TX_TIMEOUT));
1269 }
1270
1271 static bool carl9170_tx_ampdu_queue(struct ar9170 *ar,
1272         struct ieee80211_sta *sta, struct sk_buff *skb)
1273 {
1274         struct _carl9170_tx_superframe *super = (void *) skb->data;
1275         struct carl9170_sta_info *sta_info;
1276         struct carl9170_sta_tid *agg;
1277         struct sk_buff *iter;
1278         unsigned int max;
1279         u16 tid, seq, qseq, off;
1280         bool run = false;
1281
1282         tid = carl9170_get_tid(skb);
1283         seq = carl9170_get_seq(skb);
1284         sta_info = (void *) sta->drv_priv;
1285
1286         rcu_read_lock();
1287         agg = rcu_dereference(sta_info->agg[tid]);
1288         max = sta_info->ampdu_max_len;
1289
1290         if (!agg)
1291                 goto err_unlock_rcu;
1292
1293         spin_lock_bh(&agg->lock);
1294         if (unlikely(agg->state < CARL9170_TID_STATE_IDLE))
1295                 goto err_unlock;
1296
1297         /* check if sequence is within the BA window */
1298         if (unlikely(!BAW_WITHIN(agg->bsn, CARL9170_BAW_BITS, seq)))
1299                 goto err_unlock;
1300
1301         if (WARN_ON_ONCE(!BAW_WITHIN(agg->snx, CARL9170_BAW_BITS, seq)))
1302                 goto err_unlock;
1303
1304         off = SEQ_DIFF(seq, agg->bsn);
1305         if (WARN_ON_ONCE(test_and_set_bit(off, agg->bitmap)))
1306                 goto err_unlock;
1307
1308         if (likely(BAW_WITHIN(agg->hsn, CARL9170_BAW_BITS, seq))) {
1309                 __skb_queue_tail(&agg->queue, skb);
1310                 agg->hsn = seq;
1311                 goto queued;
1312         }
1313
1314         skb_queue_reverse_walk(&agg->queue, iter) {
1315                 qseq = carl9170_get_seq(iter);
1316
1317                 if (BAW_WITHIN(qseq, CARL9170_BAW_BITS, seq)) {
1318                         __skb_queue_after(&agg->queue, iter, skb);
1319                         goto queued;
1320                 }
1321         }
1322
1323         __skb_queue_head(&agg->queue, skb);
1324 queued:
1325
1326         if (unlikely(agg->state != CARL9170_TID_STATE_XMIT)) {
1327                 if (agg->snx == carl9170_get_seq(skb_peek(&agg->queue))) {
1328                         agg->state = CARL9170_TID_STATE_XMIT;
1329                         run = true;
1330                 }
1331         }
1332
1333         spin_unlock_bh(&agg->lock);
1334         rcu_read_unlock();
1335
1336         return run;
1337
1338 err_unlock:
1339         spin_unlock_bh(&agg->lock);
1340
1341 err_unlock_rcu:
1342         rcu_read_unlock();
1343         super->f.mac_control &= ~cpu_to_le16(AR9170_TX_MAC_AGGR);
1344         carl9170_tx_status(ar, skb, false);
1345         ar->tx_dropped++;
1346         return false;
1347 }
1348
1349 void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
1350 {
1351         struct ar9170 *ar = hw->priv;
1352         struct ieee80211_tx_info *info;
1353         struct ieee80211_sta *sta;
1354         bool run;
1355
1356         if (unlikely(!IS_STARTED(ar)))
1357                 goto err_free;
1358
1359         info = IEEE80211_SKB_CB(skb);
1360         sta = info->control.sta;
1361
1362         if (unlikely(carl9170_tx_prepare(ar, skb)))
1363                 goto err_free;
1364
1365         carl9170_tx_accounting(ar, skb);
1366         /*
1367          * from now on, one has to use carl9170_tx_status to free
1368          * all ressouces which are associated with the frame.
1369          */
1370
1371         if (info->flags & IEEE80211_TX_CTL_AMPDU) {
1372                 run = carl9170_tx_ampdu_queue(ar, sta, skb);
1373                 if (run)
1374                         carl9170_tx_ampdu(ar);
1375
1376         } else {
1377                 unsigned int queue = skb_get_queue_mapping(skb);
1378
1379                 skb_queue_tail(&ar->tx_pending[queue], skb);
1380         }
1381
1382         carl9170_tx(ar);
1383         return;
1384
1385 err_free:
1386         ar->tx_dropped++;
1387         dev_kfree_skb_any(skb);
1388 }
1389
1390 void carl9170_tx_scheduler(struct ar9170 *ar)
1391 {
1392
1393         if (ar->tx_ampdu_schedule)
1394                 carl9170_tx_ampdu(ar);
1395
1396         if (ar->tx_schedule)
1397                 carl9170_tx(ar);
1398 }