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

   1 /*
   2  * Atheros CARL9170 driver
   3  *
   4  * 802.11 & command trap 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 <linux/crc32.h>
  45 #include <net/mac80211.h>
  46 #include "carl9170.h"
  47 #include "hw.h"
  48 #include "cmd.h"
  49
  50 static void carl9170_dbg_message(struct ar9170 *ar, const char *buf, u32 len)
  51 {
  52         bool restart = false;
  53         enum carl9170_restart_reasons reason = CARL9170_RR_NO_REASON;
  54
  55         if (len > 3) {
  56                 if (memcmp(buf, CARL9170_ERR_MAGIC, 3) == 0) {
  57                         ar->fw.err_counter++;
  58                         if (ar->fw.err_counter > 3) {
  59                                 restart = true;
  60                                 reason = CARL9170_RR_TOO_MANY_FIRMWARE_ERRORS;
  61                         }
  62                 }
  63
  64                 if (memcmp(buf, CARL9170_BUG_MAGIC, 3) == 0) {
  65                         ar->fw.bug_counter++;
  66                         restart = true;
  67                         reason = CARL9170_RR_FATAL_FIRMWARE_ERROR;
  68                 }
  69         }
  70
  71         wiphy_info(ar->hw->wiphy, "FW: %.*s\n", len, buf);
  72
  73         if (restart)
  74                 carl9170_restart(ar, reason);
  75 }
  76
  77 static void carl9170_handle_ps(struct ar9170 *ar, struct carl9170_rsp *rsp)
  78 {
  79         u32 ps;
  80         bool new_ps;
  81
  82         ps = le32_to_cpu(rsp->psm.state);
  83
  84         new_ps = (ps & CARL9170_PSM_COUNTER) != CARL9170_PSM_WAKE;
  85         if (ar->ps.state != new_ps) {
  86                 if (!new_ps) {
  87                         ar->ps.sleep_ms = jiffies_to_msecs(jiffies -
  88                                 ar->ps.last_action);
  89                 }
  90
  91                 ar->ps.last_action = jiffies;
  92
  93                 ar->ps.state = new_ps;
  94         }
  95 }
  96
  97 static int carl9170_check_sequence(struct ar9170 *ar, unsigned int seq)
  98 {
  99         if (ar->cmd_seq < -1)
 100                 return 0;
 101
 102         /*
 103          * Initialize Counter
 104          */
 105         if (ar->cmd_seq < 0)
 106                 ar->cmd_seq = seq;
 107
 108         /*
 109          * The sequence is strictly monotonic increasing and it never skips!
 110          *
 111          * Therefore we can safely assume that whenever we received an
 112          * unexpected sequence we have lost some valuable data.
 113          */
 114         if (seq != ar->cmd_seq) {
 115                 int count;
 116
 117                 count = (seq - ar->cmd_seq) % ar->fw.cmd_bufs;
 118
 119                 wiphy_err(ar->hw->wiphy, "lost %d command responses/traps! "
 120                           "w:%d g:%d\n", count, ar->cmd_seq, seq);
 121
 122                 carl9170_restart(ar, CARL9170_RR_LOST_RSP);
 123                 return -EIO;
 124         }
 125
 126         ar->cmd_seq = (ar->cmd_seq + 1) % ar->fw.cmd_bufs;
 127         return 0;
 128 }
 129
 130 static void carl9170_cmd_callback(struct ar9170 *ar, u32 len, void *buffer)
 131 {
 132         /*
 133          * Some commands may have a variable response length
 134          * and we cannot predict the correct length in advance.
 135          * So we only check if we provided enough space for the data.
 136          */
 137         if (unlikely(ar->readlen != (len - 4))) {
 138                 dev_warn(&ar->udev->dev, "received invalid command response:"
 139                          "got %d, instead of %d\n", len - 4, ar->readlen);
 140                 print_hex_dump_bytes("carl9170 cmd:", DUMP_PREFIX_OFFSET,
 141                         ar->cmd_buf, (ar->cmd.hdr.len + 4) & 0x3f);
 142                 print_hex_dump_bytes("carl9170 rsp:", DUMP_PREFIX_OFFSET,
 143                         buffer, len);
 144                 /*
 145                  * Do not complete. The command times out,
 146                  * and we get a stack trace from there.
 147                  */
 148                 carl9170_restart(ar, CARL9170_RR_INVALID_RSP);
 149         }
 150
 151         spin_lock(&ar->cmd_lock);
 152         if (ar->readbuf) {
 153                 if (len >= 4)
 154                         memcpy(ar->readbuf, buffer + 4, len - 4);
 155
 156                 ar->readbuf = NULL;
 157         }
 158         complete(&ar->cmd_wait);
 159         spin_unlock(&ar->cmd_lock);
 160 }
 161
 162 void carl9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
 163 {
 164         struct carl9170_rsp *cmd = buf;
 165         struct ieee80211_vif *vif;
 166
 167         if (carl9170_check_sequence(ar, cmd->hdr.seq))
 168                 return;
 169
 170         if ((cmd->hdr.cmd & CARL9170_RSP_FLAG) != CARL9170_RSP_FLAG) {
 171                 if (!(cmd->hdr.cmd & CARL9170_CMD_ASYNC_FLAG))
 172                         carl9170_cmd_callback(ar, len, buf);
 173
 174                 return;
 175         }
 176
 177         if (unlikely(cmd->hdr.len != (len - 4))) {
 178                 if (net_ratelimit()) {
 179                         wiphy_err(ar->hw->wiphy, "FW: received over-/under"
 180                                 "sized event %x (%d, but should be %d).\n",
 181                                cmd->hdr.cmd, cmd->hdr.len, len - 4);
 182
 183                         print_hex_dump_bytes("dump:", DUMP_PREFIX_NONE,
 184                                              buf, len);
 185                 }
 186
 187                 return;
 188         }
 189
 190         /* hardware event handlers */
 191         switch (cmd->hdr.cmd) {
 192         case CARL9170_RSP_PRETBTT:
 193                 /* pre-TBTT event */
 194                 rcu_read_lock();
 195                 vif = carl9170_get_main_vif(ar);
 196
 197                 if (!vif) {
 198                         rcu_read_unlock();
 199                         break;
 200                 }
 201
 202                 switch (vif->type) {
 203                 case NL80211_IFTYPE_STATION:
 204                         carl9170_handle_ps(ar, cmd);
 205                         break;
 206
 207                 case NL80211_IFTYPE_AP:
 208                 case NL80211_IFTYPE_ADHOC:
 209                 case NL80211_IFTYPE_MESH_POINT:
 210                         carl9170_update_beacon(ar, true);
 211                         break;
 212
 213                 default:
 214                         break;
 215                 }
 216                 rcu_read_unlock();
 217
 218                 break;
 219
 220
 221         case CARL9170_RSP_TXCOMP:
 222                 /* TX status notification */
 223                 carl9170_tx_process_status(ar, cmd);
 224                 break;
 225
 226         case CARL9170_RSP_BEACON_CONFIG:
 227                 /*
 228                  * (IBSS) beacon send notification
 229                  * bytes: 04 c2 XX YY B4 B3 B2 B1
 230                  *
 231                  * XX always 80
 232                  * YY always 00
 233                  * B1-B4 "should" be the number of send out beacons.
 234                  */
 235                 break;
 236
 237         case CARL9170_RSP_ATIM:
 238                 /* End of Atim Window */
 239                 break;
 240
 241         case CARL9170_RSP_WATCHDOG:
 242                 /* Watchdog Interrupt */
 243                 carl9170_restart(ar, CARL9170_RR_WATCHDOG);
 244                 break;
 245
 246         case CARL9170_RSP_TEXT:
 247                 /* firmware debug */
 248                 carl9170_dbg_message(ar, (char *)buf + 4, len - 4);
 249                 break;
 250
 251         case CARL9170_RSP_HEXDUMP:
 252                 wiphy_dbg(ar->hw->wiphy, "FW: HD %d\n", len - 4);
 253                 print_hex_dump_bytes("FW:", DUMP_PREFIX_NONE,
 254                                      (char *)buf + 4, len - 4);
 255                 break;
 256
 257         case CARL9170_RSP_RADAR:
 258                 if (!net_ratelimit())
 259                         break;
 260
 261                 wiphy_info(ar->hw->wiphy, "FW: RADAR! Please report this "
 262                        "incident to linux-wireless@vger.kernel.org !\n");
 263                 break;
 264
 265         case CARL9170_RSP_GPIO:
 266 #ifdef CONFIG_CARL9170_WPC
 267                 if (ar->wps.pbc) {
 268                         bool state = !!(cmd->gpio.gpio & cpu_to_le32(
 269                                 AR9170_GPIO_PORT_WPS_BUTTON_PRESSED));
 270
 271                         if (state != ar->wps.pbc_state) {
 272                                 ar->wps.pbc_state = state;
 273                                 input_report_key(ar->wps.pbc, KEY_WPS_BUTTON,
 274                                                  state);
 275                                 input_sync(ar->wps.pbc);
 276                         }
 277                 }
 278 #endif /* CONFIG_CARL9170_WPC */
 279                 break;
 280
 281         case CARL9170_RSP_BOOT:
 282                 complete(&ar->fw_boot_wait);
 283                 break;
 284
 285         default:
 286                 wiphy_err(ar->hw->wiphy, "FW: received unhandled event %x\n",
 287                         cmd->hdr.cmd);
 288                 print_hex_dump_bytes("dump:", DUMP_PREFIX_NONE, buf, len);
 289                 break;
 290         }
 291 }
 292
 293 static int carl9170_rx_mac_status(struct ar9170 *ar,
 294         struct ar9170_rx_head *head, struct ar9170_rx_macstatus *mac,
 295         struct ieee80211_rx_status *status)
 296 {
 297         struct ieee80211_channel *chan;
 298         u8 error, decrypt;
 299
 300         BUILD_BUG_ON(sizeof(struct ar9170_rx_head) != 12);
 301         BUILD_BUG_ON(sizeof(struct ar9170_rx_macstatus) != 4);
 302
 303         error = mac->error;
 304
 305         if (error & AR9170_RX_ERROR_WRONG_RA) {
 306                 if (!ar->sniffer_enabled)
 307                         return -EINVAL;
 308         }
 309
 310         if (error & AR9170_RX_ERROR_PLCP) {
 311                 if (!(ar->filter_state & FIF_PLCPFAIL))
 312                         return -EINVAL;
 313
 314                 status->flag |= RX_FLAG_FAILED_PLCP_CRC;
 315         }
 316
 317         if (error & AR9170_RX_ERROR_FCS) {
 318                 ar->tx_fcs_errors++;
 319
 320                 if (!(ar->filter_state & FIF_FCSFAIL))
 321                         return -EINVAL;
 322
 323                 status->flag |= RX_FLAG_FAILED_FCS_CRC;
 324         }
 325
 326         decrypt = ar9170_get_decrypt_type(mac);
 327         if (!(decrypt & AR9170_RX_ENC_SOFTWARE) &&
 328             decrypt != AR9170_ENC_ALG_NONE) {
 329                 if ((decrypt == AR9170_ENC_ALG_TKIP) &&
 330                     (error & AR9170_RX_ERROR_MMIC))
 331                         status->flag |= RX_FLAG_MMIC_ERROR;
 332
 333                 status->flag |= RX_FLAG_DECRYPTED;
 334         }
 335
 336         if (error & AR9170_RX_ERROR_DECRYPT && !ar->sniffer_enabled)
 337                 return -ENODATA;
 338
 339         error &= ~(AR9170_RX_ERROR_MMIC |
 340                    AR9170_RX_ERROR_FCS |
 341                    AR9170_RX_ERROR_WRONG_RA |
 342                    AR9170_RX_ERROR_DECRYPT |
 343                    AR9170_RX_ERROR_PLCP);
 344
 345         /* drop any other error frames */
 346         if (unlikely(error)) {
 347                 /* TODO: update netdevice's RX dropped/errors statistics */
 348
 349                 if (net_ratelimit())
 350                         wiphy_dbg(ar->hw->wiphy, "received frame with "
 351                                "suspicious error code (%#x).\n", error);
 352
 353                 return -EINVAL;
 354         }
 355
 356         chan = ar->channel;
 357         if (chan) {
 358                 status->band = chan->band;
 359                 status->freq = chan->center_freq;
 360         }
 361
 362         switch (mac->status & AR9170_RX_STATUS_MODULATION) {
 363         case AR9170_RX_STATUS_MODULATION_CCK:
 364                 if (mac->status & AR9170_RX_STATUS_SHORT_PREAMBLE)
 365                         status->flag |= RX_FLAG_SHORTPRE;
 366                 switch (head->plcp[0]) {
 367                 case AR9170_RX_PHY_RATE_CCK_1M:
 368                         status->rate_idx = 0;
 369                         break;
 370                 case AR9170_RX_PHY_RATE_CCK_2M:
 371                         status->rate_idx = 1;
 372                         break;
 373                 case AR9170_RX_PHY_RATE_CCK_5M:
 374                         status->rate_idx = 2;
 375                         break;
 376                 case AR9170_RX_PHY_RATE_CCK_11M:
 377                         status->rate_idx = 3;
 378                         break;
 379                 default:
 380                         if (net_ratelimit()) {
 381                                 wiphy_err(ar->hw->wiphy, "invalid plcp cck "
 382                                        "rate (%x).\n", head->plcp[0]);
 383                         }
 384
 385                         return -EINVAL;
 386                 }
 387                 break;
 388
 389         case AR9170_RX_STATUS_MODULATION_DUPOFDM:
 390         case AR9170_RX_STATUS_MODULATION_OFDM:
 391                 switch (head->plcp[0] & 0xf) {
 392                 case AR9170_TXRX_PHY_RATE_OFDM_6M:
 393                         status->rate_idx = 0;
 394                         break;
 395                 case AR9170_TXRX_PHY_RATE_OFDM_9M:
 396                         status->rate_idx = 1;
 397                         break;
 398                 case AR9170_TXRX_PHY_RATE_OFDM_12M:
 399                         status->rate_idx = 2;
 400                         break;
 401                 case AR9170_TXRX_PHY_RATE_OFDM_18M:
 402                         status->rate_idx = 3;
 403                         break;
 404                 case AR9170_TXRX_PHY_RATE_OFDM_24M:
 405                         status->rate_idx = 4;
 406                         break;
 407                 case AR9170_TXRX_PHY_RATE_OFDM_36M:
 408                         status->rate_idx = 5;
 409                         break;
 410                 case AR9170_TXRX_PHY_RATE_OFDM_48M:
 411                         status->rate_idx = 6;
 412                         break;
 413                 case AR9170_TXRX_PHY_RATE_OFDM_54M:
 414                         status->rate_idx = 7;
 415                         break;
 416                 default:
 417                         if (net_ratelimit()) {
 418                                 wiphy_err(ar->hw->wiphy, "invalid plcp ofdm "
 419                                         "rate (%x).\n", head->plcp[0]);
 420                         }
 421
 422                         return -EINVAL;
 423                 }
 424                 if (status->band == IEEE80211_BAND_2GHZ)
 425                         status->rate_idx += 4;
 426                 break;
 427
 428         case AR9170_RX_STATUS_MODULATION_HT:
 429                 if (head->plcp[3] & 0x80)
 430                         status->flag |= RX_FLAG_40MHZ;
 431                 if (head->plcp[6] & 0x80)
 432                         status->flag |= RX_FLAG_SHORT_GI;
 433
 434                 status->rate_idx = clamp(0, 75, head->plcp[3] & 0x7f);
 435                 status->flag |= RX_FLAG_HT;
 436                 break;
 437
 438         default:
 439                 BUG();
 440                 return -ENOSYS;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static void carl9170_rx_phy_status(struct ar9170 *ar,
 447         struct ar9170_rx_phystatus *phy, struct ieee80211_rx_status *status)
 448 {
 449         int i;
 450
 451         BUILD_BUG_ON(sizeof(struct ar9170_rx_phystatus) != 20);
 452
 453         for (i = 0; i < 3; i++)
 454                 if (phy->rssi[i] != 0x80)
 455                         status->antenna |= BIT(i);
 456
 457         /* post-process RSSI */
 458         for (i = 0; i < 7; i++)
 459                 if (phy->rssi[i] & 0x80)
 460                         phy->rssi[i] = ((phy->rssi[i] & 0x7f) + 1) & 0x7f;
 461
 462         /* TODO: we could do something with phy_errors */
 463         status->signal = ar->noise[0] + phy->rssi_combined;
 464 }
 465
 466 static struct sk_buff *carl9170_rx_copy_data(u8 *buf, int len)
 467 {
 468         struct sk_buff *skb;
 469         int reserved = 0;
 470         struct ieee80211_hdr *hdr = (void *) buf;
 471
 472         if (ieee80211_is_data_qos(hdr->frame_control)) {
 473                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 474                 reserved += NET_IP_ALIGN;
 475
 476                 if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
 477                         reserved += NET_IP_ALIGN;
 478         }
 479
 480         if (ieee80211_has_a4(hdr->frame_control))
 481                 reserved += NET_IP_ALIGN;
 482
 483         reserved = 32 + (reserved & NET_IP_ALIGN);
 484
 485         skb = dev_alloc_skb(len + reserved);
 486         if (likely(skb)) {
 487                 skb_reserve(skb, reserved);
 488                 memcpy(skb_put(skb, len), buf, len);
 489         }
 490
 491         return skb;
 492 }
 493
 494 static u8 *carl9170_find_ie(u8 *data, unsigned int len, u8 ie)
 495 {
 496         struct ieee80211_mgmt *mgmt = (void *)data;
 497         u8 *pos, *end;
 498
 499         pos = (u8 *)mgmt->u.beacon.variable;
 500         end = data + len;
 501         while (pos < end) {
 502                 if (pos + 2 + pos[1] > end)
 503                         return NULL;
 504
 505                 if (pos[0] == ie)
 506                         return pos;
 507
 508                 pos += 2 + pos[1];
 509         }
 510         return NULL;
 511 }
 512
 513 /*
 514  * NOTE:
 515  *
 516  * The firmware is in charge of waking up the device just before
 517  * the AP is expected to transmit the next beacon.
 518  *
 519  * This leaves the driver with the important task of deciding when
 520  * to set the PHY back to bed again.
 521  */
 522 static void carl9170_ps_beacon(struct ar9170 *ar, void *data, unsigned int len)
 523 {
 524         struct ieee80211_hdr *hdr = data;
 525         struct ieee80211_tim_ie *tim_ie;
 526         u8 *tim;
 527         u8 tim_len;
 528         bool cam;
 529
 530         if (likely(!(ar->hw->conf.flags & IEEE80211_CONF_PS)))
 531                 return;
 532
 533         /* check if this really is a beacon */
 534         if (!ieee80211_is_beacon(hdr->frame_control))
 535                 return;
 536
 537         /* min. beacon length + FCS_LEN */
 538         if (len <= 40 + FCS_LEN)
 539                 return;
 540
 541         /* and only beacons from the associated BSSID, please */
 542         if (!ether_addr_equal(hdr->addr3, ar->common.curbssid) ||
 543             !ar->common.curaid)
 544                 return;
 545
 546         ar->ps.last_beacon = jiffies;
 547
 548         tim = carl9170_find_ie(data, len - FCS_LEN, WLAN_EID_TIM);
 549         if (!tim)
 550                 return;
 551
 552         if (tim[1] < sizeof(*tim_ie))
 553                 return;
 554
 555         tim_len = tim[1];
 556         tim_ie = (struct ieee80211_tim_ie *) &tim[2];
 557
 558         if (!WARN_ON_ONCE(!ar->hw->conf.ps_dtim_period))
 559                 ar->ps.dtim_counter = (tim_ie->dtim_count - 1) %
 560                         ar->hw->conf.ps_dtim_period;
 561
 562         /* Check whenever the PHY can be turned off again. */
 563
 564         /* 1. What about buffered unicast traffic for our AID? */
 565         cam = ieee80211_check_tim(tim_ie, tim_len, ar->common.curaid);
 566
 567         /* 2. Maybe the AP wants to send multicast/broadcast data? */
 568         cam |= !!(tim_ie->bitmap_ctrl & 0x01);
 569
 570         if (!cam) {
 571                 /* back to low-power land. */
 572                 ar->ps.off_override &= ~PS_OFF_BCN;
 573                 carl9170_ps_check(ar);
 574         } else {
 575                 /* force CAM */
 576                 ar->ps.off_override |= PS_OFF_BCN;
 577         }
 578 }
 579
 580 static void carl9170_ba_check(struct ar9170 *ar, void *data, unsigned int len)
 581 {
 582         struct ieee80211_bar *bar = (void *) data;
 583         struct carl9170_bar_list_entry *entry;
 584         unsigned int queue;
 585
 586         if (likely(!ieee80211_is_back(bar->frame_control)))
 587                 return;
 588
 589         if (len <= sizeof(*bar) + FCS_LEN)
 590                 return;
 591
 592         queue = TID_TO_WME_AC(((le16_to_cpu(bar->control) &
 593                 IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
 594                 IEEE80211_BAR_CTRL_TID_INFO_SHIFT) & 7);
 595
 596         rcu_read_lock();
 597         list_for_each_entry_rcu(entry, &ar->bar_list[queue], list) {
 598                 struct sk_buff *entry_skb = entry->skb;
 599                 struct _carl9170_tx_superframe *super = (void *)entry_skb->data;
 600                 struct ieee80211_bar *entry_bar = (void *)super->frame_data;
 601
 602 #define TID_CHECK(a, b) (                                               \
 603         ((a) & cpu_to_le16(IEEE80211_BAR_CTRL_TID_INFO_MASK)) ==        \
 604         ((b) & cpu_to_le16(IEEE80211_BAR_CTRL_TID_INFO_MASK)))          \
 605
 606                 if (bar->start_seq_num == entry_bar->start_seq_num &&
 607                     TID_CHECK(bar->control, entry_bar->control) &&
 608                     compare_ether_addr(bar->ra, entry_bar->ta) == 0 &&
 609                     compare_ether_addr(bar->ta, entry_bar->ra) == 0) {
 610                         struct ieee80211_tx_info *tx_info;
 611
 612                         tx_info = IEEE80211_SKB_CB(entry_skb);
 613                         tx_info->flags |= IEEE80211_TX_STAT_ACK;
 614
 615                         spin_lock_bh(&ar->bar_list_lock[queue]);
 616                         list_del_rcu(&entry->list);
 617                         spin_unlock_bh(&ar->bar_list_lock[queue]);
 618                         kfree_rcu(entry, head);
 619                         break;
 620                 }
 621         }
 622         rcu_read_unlock();
 623
 624 #undef TID_CHECK
 625 }
 626
 627 static bool carl9170_ampdu_check(struct ar9170 *ar, u8 *buf, u8 ms)
 628 {
 629         __le16 fc;
 630
 631         if ((ms & AR9170_RX_STATUS_MPDU) == AR9170_RX_STATUS_MPDU_SINGLE) {
 632                 /*
 633                  * This frame is not part of an aMPDU.
 634                  * Therefore it is not subjected to any
 635                  * of the following content restrictions.
 636                  */
 637                 return true;
 638         }
 639
 640         /*
 641          * "802.11n - 7.4a.3 A-MPDU contents" describes in which contexts
 642          * certain frame types can be part of an aMPDU.
 643          *
 644          * In order to keep the processing cost down, I opted for a
 645          * stateless filter solely based on the frame control field.
 646          */
 647
 648         fc = ((struct ieee80211_hdr *)buf)->frame_control;
 649         if (ieee80211_is_data_qos(fc) && ieee80211_is_data_present(fc))
 650                 return true;
 651
 652         if (ieee80211_is_ack(fc) || ieee80211_is_back(fc) ||
 653             ieee80211_is_back_req(fc))
 654                 return true;
 655
 656         if (ieee80211_is_action(fc))
 657                 return true;
 658
 659         return false;
 660 }
 661
 662 /*
 663  * If the frame alignment is right (or the kernel has
 664  * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS), and there
 665  * is only a single MPDU in the USB frame, then we could
 666  * submit to mac80211 the SKB directly. However, since
 667  * there may be multiple packets in one SKB in stream
 668  * mode, and we need to observe the proper ordering,
 669  * this is non-trivial.
 670  */
 671
 672 static void carl9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
 673 {
 674         struct ar9170_rx_head *head;
 675         struct ar9170_rx_macstatus *mac;
 676         struct ar9170_rx_phystatus *phy = NULL;
 677         struct ieee80211_rx_status status;
 678         struct sk_buff *skb;
 679         int mpdu_len;
 680         u8 mac_status;
 681
 682         if (!IS_STARTED(ar))
 683                 return;
 684
 685         if (unlikely(len < sizeof(*mac)))
 686                 goto drop;
 687
 688         mpdu_len = len - sizeof(*mac);
 689
 690         mac = (void *)(buf + mpdu_len);
 691         mac_status = mac->status;
 692         switch (mac_status & AR9170_RX_STATUS_MPDU) {
 693         case AR9170_RX_STATUS_MPDU_FIRST:
 694                 /* Aggregated MPDUs start with an PLCP header */
 695                 if (likely(mpdu_len >= sizeof(struct ar9170_rx_head))) {
 696                         head = (void *) buf;
 697
 698                         /*
 699                          * The PLCP header needs to be cached for the
 700                          * following MIDDLE + LAST A-MPDU packets.
 701                          *
 702                          * So, if you are wondering why all frames seem
 703                          * to share a common RX status information,
 704                          * then you have the answer right here...
 705                          */
 706                         memcpy(&ar->rx_plcp, (void *) buf,
 707                                sizeof(struct ar9170_rx_head));
 708
 709                         mpdu_len -= sizeof(struct ar9170_rx_head);
 710                         buf += sizeof(struct ar9170_rx_head);
 711
 712                         ar->rx_has_plcp = true;
 713                 } else {
 714                         if (net_ratelimit()) {
 715                                 wiphy_err(ar->hw->wiphy, "plcp info "
 716                                         "is clipped.\n");
 717                         }
 718
 719                         goto drop;
 720                 }
 721                 break;
 722
 723         case AR9170_RX_STATUS_MPDU_LAST:
 724                 /*
 725                  * The last frame of an A-MPDU has an extra tail
 726                  * which does contain the phy status of the whole
 727                  * aggregate.
 728                  */
 729
 730                 if (likely(mpdu_len >= sizeof(struct ar9170_rx_phystatus))) {
 731                         mpdu_len -= sizeof(struct ar9170_rx_phystatus);
 732                         phy = (void *)(buf + mpdu_len);
 733                 } else {
 734                         if (net_ratelimit()) {
 735                                 wiphy_err(ar->hw->wiphy, "frame tail "
 736                                         "is clipped.\n");
 737                         }
 738
 739                         goto drop;
 740                 }
 741
 742         case AR9170_RX_STATUS_MPDU_MIDDLE:
 743                 /*  These are just data + mac status */
 744                 if (unlikely(!ar->rx_has_plcp)) {
 745                         if (!net_ratelimit())
 746                                 return;
 747
 748                         wiphy_err(ar->hw->wiphy, "rx stream does not start "
 749                                         "with a first_mpdu frame tag.\n");
 750
 751                         goto drop;
 752                 }
 753
 754                 head = &ar->rx_plcp;
 755                 break;
 756
 757         case AR9170_RX_STATUS_MPDU_SINGLE:
 758                 /* single mpdu has both: plcp (head) and phy status (tail) */
 759                 head = (void *) buf;
 760
 761                 mpdu_len -= sizeof(struct ar9170_rx_head);
 762                 mpdu_len -= sizeof(struct ar9170_rx_phystatus);
 763
 764                 buf += sizeof(struct ar9170_rx_head);
 765                 phy = (void *)(buf + mpdu_len);
 766                 break;
 767
 768         default:
 769                 BUG_ON(1);
 770                 break;
 771         }
 772
 773         /* FC + DU + RA + FCS */
 774         if (unlikely(mpdu_len < (2 + 2 + ETH_ALEN + FCS_LEN)))
 775                 goto drop;
 776
 777         memset(&status, 0, sizeof(status));
 778         if (unlikely(carl9170_rx_mac_status(ar, head, mac, &status)))
 779                 goto drop;
 780
 781         if (!carl9170_ampdu_check(ar, buf, mac_status))
 782                 goto drop;
 783
 784         if (phy)
 785                 carl9170_rx_phy_status(ar, phy, &status);
 786
 787         carl9170_ps_beacon(ar, buf, mpdu_len);
 788
 789         carl9170_ba_check(ar, buf, mpdu_len);
 790
 791         skb = carl9170_rx_copy_data(buf, mpdu_len);
 792         if (!skb)
 793                 goto drop;
 794
 795         memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
 796         ieee80211_rx(ar->hw, skb);
 797         return;
 798
 799 drop:
 800         ar->rx_dropped++;
 801 }
 802
 803 static void carl9170_rx_untie_cmds(struct ar9170 *ar, const u8 *respbuf,
 804                                    const unsigned int resplen)
 805 {
 806         struct carl9170_rsp *cmd;
 807         int i = 0;
 808
 809         while (i < resplen) {
 810                 cmd = (void *) &respbuf[i];
 811
 812                 i += cmd->hdr.len + 4;
 813                 if (unlikely(i > resplen))
 814                         break;
 815
 816                 carl9170_handle_command_response(ar, cmd, cmd->hdr.len + 4);
 817         }
 818
 819         if (unlikely(i != resplen)) {
 820                 if (!net_ratelimit())
 821                         return;
 822
 823                 wiphy_err(ar->hw->wiphy, "malformed firmware trap:\n");
 824                 print_hex_dump_bytes("rxcmd:", DUMP_PREFIX_OFFSET,
 825                                      respbuf, resplen);
 826         }
 827 }
 828
 829 static void __carl9170_rx(struct ar9170 *ar, u8 *buf, unsigned int len)
 830 {
 831         unsigned int i = 0;
 832
 833         /* weird thing, but this is the same in the original driver */
 834         while (len > 2 && i < 12 && buf[0] == 0xff && buf[1] == 0xff) {
 835                 i += 2;
 836                 len -= 2;
 837                 buf += 2;
 838         }
 839
 840         if (unlikely(len < 4))
 841                 return;
 842
 843         /* found the 6 * 0xffff marker? */
 844         if (i == 12)
 845                 carl9170_rx_untie_cmds(ar, buf, len);
 846         else
 847                 carl9170_handle_mpdu(ar, buf, len);
 848 }
 849
 850 static void carl9170_rx_stream(struct ar9170 *ar, void *buf, unsigned int len)
 851 {
 852         unsigned int tlen, wlen = 0, clen = 0;
 853         struct ar9170_stream *rx_stream;
 854         u8 *tbuf;
 855
 856         tbuf = buf;
 857         tlen = len;
 858
 859         while (tlen >= 4) {
 860                 rx_stream = (void *) tbuf;
 861                 clen = le16_to_cpu(rx_stream->length);
 862                 wlen = ALIGN(clen, 4);
 863
 864                 /* check if this is stream has a valid tag.*/
 865                 if (rx_stream->tag != cpu_to_le16(AR9170_RX_STREAM_TAG)) {
 866                         /*
 867                          * TODO: handle the highly unlikely event that the
 868                          * corrupted stream has the TAG at the right position.
 869                          */
 870
 871                         /* check if the frame can be repaired. */
 872                         if (!ar->rx_failover_missing) {
 873
 874                                 /* this is not "short read". */
 875                                 if (net_ratelimit()) {
 876                                         wiphy_err(ar->hw->wiphy,
 877                                                 "missing tag!\n");
 878                                 }
 879
 880                                 __carl9170_rx(ar, tbuf, tlen);
 881                                 return;
 882                         }
 883
 884                         if (ar->rx_failover_missing > tlen) {
 885                                 if (net_ratelimit()) {
 886                                         wiphy_err(ar->hw->wiphy,
 887                                                 "possible multi "
 888                                                 "stream corruption!\n");
 889                                         goto err_telluser;
 890                                 } else {
 891                                         goto err_silent;
 892                                 }
 893                         }
 894
 895                         memcpy(skb_put(ar->rx_failover, tlen), tbuf, tlen);
 896                         ar->rx_failover_missing -= tlen;
 897
 898                         if (ar->rx_failover_missing <= 0) {
 899                                 /*
 900                                  * nested carl9170_rx_stream call!
 901                                  *
 902                                  * termination is guaranteed, even when the
 903                                  * combined frame also have an element with
 904                                  * a bad tag.
 905                                  */
 906
 907                                 ar->rx_failover_missing = 0;
 908                                 carl9170_rx_stream(ar, ar->rx_failover->data,
 909                                                    ar->rx_failover->len);
 910
 911                                 skb_reset_tail_pointer(ar->rx_failover);
 912                                 skb_trim(ar->rx_failover, 0);
 913                         }
 914
 915                         return;
 916                 }
 917
 918                 /* check if stream is clipped */
 919                 if (wlen > tlen - 4) {
 920                         if (ar->rx_failover_missing) {
 921                                 /* TODO: handle double stream corruption. */
 922                                 if (net_ratelimit()) {
 923                                         wiphy_err(ar->hw->wiphy, "double rx "
 924                                                 "stream corruption!\n");
 925                                         goto err_telluser;
 926                                 } else {
 927                                         goto err_silent;
 928                                 }
 929                         }
 930
 931                         /*
 932                          * save incomplete data set.
 933                          * the firmware will resend the missing bits when
 934                          * the rx - descriptor comes round again.
 935                          */
 936
 937                         memcpy(skb_put(ar->rx_failover, tlen), tbuf, tlen);
 938                         ar->rx_failover_missing = clen - tlen;
 939                         return;
 940                 }
 941                 __carl9170_rx(ar, rx_stream->payload, clen);
 942
 943                 tbuf += wlen + 4;
 944                 tlen -= wlen + 4;
 945         }
 946
 947         if (tlen) {
 948                 if (net_ratelimit()) {
 949                         wiphy_err(ar->hw->wiphy, "%d bytes of unprocessed "
 950                                 "data left in rx stream!\n", tlen);
 951                 }
 952
 953                 goto err_telluser;
 954         }
 955
 956         return;
 957
 958 err_telluser:
 959         wiphy_err(ar->hw->wiphy, "damaged RX stream data [want:%d, "
 960                 "data:%d, rx:%d, pending:%d ]\n", clen, wlen, tlen,
 961                 ar->rx_failover_missing);
 962
 963         if (ar->rx_failover_missing)
 964                 print_hex_dump_bytes("rxbuf:", DUMP_PREFIX_OFFSET,
 965                                      ar->rx_failover->data,
 966                                      ar->rx_failover->len);
 967
 968         print_hex_dump_bytes("stream:", DUMP_PREFIX_OFFSET,
 969                              buf, len);
 970
 971         wiphy_err(ar->hw->wiphy, "please check your hardware and cables, if "
 972                 "you see this message frequently.\n");
 973
 974 err_silent:
 975         if (ar->rx_failover_missing) {
 976                 skb_reset_tail_pointer(ar->rx_failover);
 977                 skb_trim(ar->rx_failover, 0);
 978                 ar->rx_failover_missing = 0;
 979         }
 980 }
 981
 982 void carl9170_rx(struct ar9170 *ar, void *buf, unsigned int len)
 983 {
 984         if (ar->fw.rx_stream)
 985                 carl9170_rx_stream(ar, buf, len);
 986         else
 987                 __carl9170_rx(ar, buf, len);
 988 }