drivers/net/wireless/wl1251/tx.c

   1 /*
   2  * This file is part of wl1251
   3  *
   4  * Copyright (c) 1998-2007 Texas Instruments Incorporated
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25
  26 #include "wl1251.h"
  27 #include "reg.h"
  28 #include "tx.h"
  29 #include "ps.h"
  30 #include "io.h"
  31 #include "event.h"
  32
  33 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  34 {
  35         int used, data_in_count;
  36
  37         data_in_count = wl->data_in_count;
  38
  39         if (data_in_count < data_out_count)
  40                 /* data_in_count has wrapped */
  41                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  42
  43         used = data_in_count - data_out_count;
  44
  45         WARN_ON(used < 0);
  46         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  47
  48         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  49                 return true;
  50         else
  51                 return false;
  52 }
  53
  54 int wl1251_tx_path_status(struct wl1251 *wl)
  55 {
  56         u32 status, addr, data_out_count;
  57         bool busy;
  58
  59         addr = wl->data_path->tx_control_addr;
  60         status = wl1251_mem_read32(wl, addr);
  61         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  62         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  63
  64         if (busy)
  65                 return -EBUSY;
  66
  67         return 0;
  68 }
  69
  70 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  71 {
  72         int i;
  73
  74         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  75                 if (wl->tx_frames[i] == NULL) {
  76                         wl->tx_frames[i] = skb;
  77                         return i;
  78                 }
  79
  80         return -EBUSY;
  81 }
  82
  83 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  84                               struct ieee80211_tx_info *control, u16 fc)
  85 {
  86         *(u16 *)&tx_hdr->control = 0;
  87
  88         tx_hdr->control.rate_policy = 0;
  89
  90         /* 802.11 packets */
  91         tx_hdr->control.packet_type = 0;
  92
  93         /* Also disable retry and ACK policy for injected packets */
  94         if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
  95             (control->flags & IEEE80211_TX_CTL_INJECTED)) {
  96                 tx_hdr->control.rate_policy = 1;
  97                 tx_hdr->control.ack_policy = 1;
  98         }
  99
 100         tx_hdr->control.tx_complete = 1;
 101
 102         if ((fc & IEEE80211_FTYPE_DATA) &&
 103             ((fc & IEEE80211_STYPE_QOS_DATA) ||
 104              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
 105                 tx_hdr->control.qos = 1;
 106 }
 107
 108 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
 109 #define MAX_MSDU_SECURITY_LENGTH      16
 110 #define MAX_MPDU_SECURITY_LENGTH      16
 111 #define WLAN_QOS_HDR_LEN              26
 112 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
 113                                        WLAN_QOS_HDR_LEN)
 114 #define HW_BLOCK_SIZE                 252
 115 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 116 {
 117         u16 payload_len, frag_threshold, mem_blocks;
 118         u16 num_mpdus, mem_blocks_per_frag;
 119
 120         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 121         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 122
 123         payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 124
 125         if (payload_len > frag_threshold) {
 126                 mem_blocks_per_frag =
 127                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 128                          HW_BLOCK_SIZE) + 1;
 129                 num_mpdus = payload_len / frag_threshold;
 130                 mem_blocks = num_mpdus * mem_blocks_per_frag;
 131                 payload_len -= num_mpdus * frag_threshold;
 132                 num_mpdus++;
 133
 134         } else {
 135                 mem_blocks_per_frag = 0;
 136                 mem_blocks = 0;
 137                 num_mpdus = 1;
 138         }
 139
 140         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 141
 142         if (num_mpdus > 1)
 143                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 144
 145         tx_hdr->num_mem_blocks = mem_blocks;
 146 }
 147
 148 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 149                               struct ieee80211_tx_info *control)
 150 {
 151         struct tx_double_buffer_desc *tx_hdr;
 152         struct ieee80211_rate *rate;
 153         int id;
 154         u16 fc;
 155
 156         if (!skb)
 157                 return -EINVAL;
 158
 159         id = wl1251_tx_id(wl, skb);
 160         if (id < 0)
 161                 return id;
 162
 163         fc = *(u16 *)skb->data;
 164         tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
 165                                                            sizeof(*tx_hdr));
 166
 167         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 168         rate = ieee80211_get_tx_rate(wl->hw, control);
 169         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 170         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 171         tx_hdr->id = id;
 172
 173         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 174
 175         wl1251_tx_control(tx_hdr, control, fc);
 176         wl1251_tx_frag_block_num(tx_hdr);
 177
 178         return 0;
 179 }
 180
 181 /* We copy the packet to the target */
 182 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 183                                  struct ieee80211_tx_info *control)
 184 {
 185         struct tx_double_buffer_desc *tx_hdr;
 186         int len;
 187         u32 addr;
 188
 189         if (!skb)
 190                 return -EINVAL;
 191
 192         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 193
 194         if (control->control.hw_key &&
 195             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 196                 int hdrlen;
 197                 __le16 fc;
 198                 u16 length;
 199                 u8 *pos;
 200
 201                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 202                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 203                 tx_hdr->length = cpu_to_le16(length);
 204
 205                 hdrlen = ieee80211_hdrlen(fc);
 206
 207                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 208                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 209                         sizeof(*tx_hdr) + hdrlen);
 210         }
 211
 212         /* Revisit. This is a workaround for getting non-aligned packets.
 213            This happens at least with EAPOL packets from the user space.
 214            Our DMA requires packets to be aligned on a 4-byte boundary.
 215         */
 216         if (unlikely((long)skb->data & 0x03)) {
 217                 int offset = (4 - (long)skb->data) & 0x03;
 218                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 219
 220                 /* check whether the current skb can be used */
 221                 if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 222                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 223                                                                  GFP_KERNEL);
 224
 225                         if (unlikely(newskb == NULL)) {
 226                                 wl1251_error("Can't allocate skb!");
 227                                 return -EINVAL;
 228                         }
 229
 230                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 231
 232                         dev_kfree_skb_any(skb);
 233                         wl->tx_frames[tx_hdr->id] = skb = newskb;
 234
 235                         offset = (4 - (long)skb->data) & 0x03;
 236                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 237                 }
 238
 239                 /* align the buffer on a 4-byte boundary */
 240                 if (offset) {
 241                         unsigned char *src = skb->data;
 242                         skb_reserve(skb, offset);
 243                         memmove(skb->data, src, skb->len);
 244                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 245                 }
 246         }
 247
 248         /* Our skb->data at this point includes the HW header */
 249         len = WL1251_TX_ALIGN(skb->len);
 250
 251         if (wl->data_in_count & 0x1)
 252                 addr = wl->data_path->tx_packet_ring_addr +
 253                         wl->data_path->tx_packet_ring_chunk_size;
 254         else
 255                 addr = wl->data_path->tx_packet_ring_addr;
 256
 257         wl1251_mem_write(wl, addr, skb->data, len);
 258
 259         wl1251_update_rate(wl, len);
 260         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 261                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 262                      tx_hdr->rate, tx_hdr->xmit_queue);
 263
 264         return 0;
 265 }
 266
 267 static void wl1251_tx_trigger(struct wl1251 *wl)
 268 {
 269         u32 data, addr;
 270
 271         if (wl->data_in_count & 0x1) {
 272                 addr = ACX_REG_INTERRUPT_TRIG_H;
 273                 data = INTR_TRIG_TX_PROC1;
 274         } else {
 275                 addr = ACX_REG_INTERRUPT_TRIG;
 276                 data = INTR_TRIG_TX_PROC0;
 277         }
 278
 279         wl1251_reg_write32(wl, addr, data);
 280
 281         /* Bumping data in */
 282         wl->data_in_count = (wl->data_in_count + 1) &
 283                 TX_STATUS_DATA_OUT_COUNT_MASK;
 284 }
 285
 286 static void enable_tx_for_packet_injection(struct wl1251 *wl)
 287 {
 288         int ret;
 289
 290         ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
 291                               wl->beacon_int, wl->dtim_period);
 292         if (ret < 0) {
 293                 wl1251_warning("join failed");
 294                 return;
 295         }
 296
 297         ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
 298         if (ret < 0) {
 299                 wl1251_warning("join timeout");
 300                 return;
 301         }
 302
 303         wl->joined = true;
 304 }
 305
 306 /* caller must hold wl->mutex */
 307 int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 308 {
 309         struct ieee80211_tx_info *info;
 310         int ret = 0;
 311         u8 idx;
 312
 313         info = IEEE80211_SKB_CB(skb);
 314
 315         if (info->control.hw_key) {
 316                 if (unlikely(wl->monitor_present))
 317                         return -EINVAL;
 318
 319                 idx = info->control.hw_key->hw_key_idx;
 320                 if (unlikely(wl->default_key != idx)) {
 321                         ret = wl1251_acx_default_key(wl, idx);
 322                         if (ret < 0)
 323                                 return ret;
 324                 }
 325         }
 326
 327         /* Enable tx path in monitor mode for packet injection */
 328         if ((wl->vif == NULL) && !wl->joined)
 329                 enable_tx_for_packet_injection(wl);
 330
 331         ret = wl1251_tx_path_status(wl);
 332         if (ret < 0)
 333                 return ret;
 334
 335         ret = wl1251_tx_fill_hdr(wl, skb, info);
 336         if (ret < 0)
 337                 return ret;
 338
 339         ret = wl1251_tx_send_packet(wl, skb, info);
 340         if (ret < 0)
 341                 return ret;
 342
 343         wl1251_tx_trigger(wl);
 344
 345         return ret;
 346 }
 347
 348 void wl1251_tx_work_unlocked(struct wl1251 *wl, bool need_pm)
 349 {
 350         struct sk_buff *skb;
 351         bool woken_up = false;
 352         int ret;
 353
 354         if (unlikely(wl->state == WL1251_STATE_OFF))
 355                 goto out;
 356
 357         while ((skb = skb_dequeue(&wl->tx_queue))) {
 358                 if (need_pm && !woken_up) {
 359                         ret = wl1251_ps_elp_wakeup(wl);
 360                         if (ret < 0)
 361                                 goto out;
 362                         woken_up = true;
 363                 }
 364
 365                 ret = wl1251_tx_frame(wl, skb);
 366                 if (ret == -EBUSY) {
 367                         skb_queue_head(&wl->tx_queue, skb);
 368                         goto out;
 369                 } else if (ret < 0) {
 370                         dev_kfree_skb(skb);
 371                         goto out;
 372                 }
 373         }
 374
 375 out:
 376         if (woken_up)
 377                 wl1251_ps_elp_sleep(wl);
 378 }
 379
 380 void wl1251_tx_work(struct work_struct *work)
 381 {
 382         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 383
 384         mutex_lock(&wl->mutex);
 385         wl1251_tx_work_unlocked(wl, true);
 386         mutex_unlock(&wl->mutex);
 387 }
 388
 389 static const char *wl1251_tx_parse_status(u8 status)
 390 {
 391         /* 8 bit status field, one character per bit plus null */
 392         static char buf[9];
 393         int i = 0;
 394
 395         memset(buf, 0, sizeof(buf));
 396
 397         if (status & TX_DMA_ERROR)
 398                 buf[i++] = 'm';
 399         if (status & TX_DISABLED)
 400                 buf[i++] = 'd';
 401         if (status & TX_RETRY_EXCEEDED)
 402                 buf[i++] = 'r';
 403         if (status & TX_TIMEOUT)
 404                 buf[i++] = 't';
 405         if (status & TX_KEY_NOT_FOUND)
 406                 buf[i++] = 'k';
 407         if (status & TX_ENCRYPT_FAIL)
 408                 buf[i++] = 'e';
 409         if (status & TX_UNAVAILABLE_PRIORITY)
 410                 buf[i++] = 'p';
 411
 412         /* bit 0 is unused apparently */
 413
 414         return buf;
 415 }
 416
 417 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 418                                 struct tx_result *result)
 419 {
 420         struct ieee80211_tx_info *info;
 421         struct sk_buff *skb;
 422         int hdrlen;
 423         u8 *frame;
 424
 425         skb = wl->tx_frames[result->id];
 426         if (skb == NULL) {
 427                 wl1251_error("SKB for packet %d is NULL", result->id);
 428                 return;
 429         }
 430
 431         info = IEEE80211_SKB_CB(skb);
 432
 433         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 434             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 435             (result->status == TX_SUCCESS))
 436                 info->flags |= IEEE80211_TX_STAT_ACK;
 437
 438         info->status.rates[0].count = result->ack_failures + 1;
 439         wl->stats.retry_count += result->ack_failures;
 440
 441         /*
 442          * We have to remove our private TX header before pushing
 443          * the skb back to mac80211.
 444          */
 445         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 446         if (info->control.hw_key &&
 447             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 448                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 449                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 450                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 451         }
 452
 453         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 454                      " status 0x%x (%s)",
 455                      result->id, skb, result->ack_failures, result->rate,
 456                      result->status, wl1251_tx_parse_status(result->status));
 457
 458
 459         ieee80211_tx_status(wl->hw, skb);
 460
 461         wl->tx_frames[result->id] = NULL;
 462 }
 463
 464 /* Called upon reception of a TX complete interrupt */
 465 void wl1251_tx_complete(struct wl1251 *wl)
 466 {
 467         int i, result_index, num_complete = 0, queue_len;
 468         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 469         unsigned long flags;
 470
 471         if (unlikely(wl->state != WL1251_STATE_ON))
 472                 return;
 473
 474         /* First we read the result */
 475         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 476                             result, sizeof(result));
 477
 478         result_index = wl->next_tx_complete;
 479
 480         for (i = 0; i < ARRAY_SIZE(result); i++) {
 481                 result_ptr = &result[result_index];
 482
 483                 if (result_ptr->done_1 == 1 &&
 484                     result_ptr->done_2 == 1) {
 485                         wl1251_tx_packet_cb(wl, result_ptr);
 486
 487                         result_ptr->done_1 = 0;
 488                         result_ptr->done_2 = 0;
 489
 490                         result_index = (result_index + 1) &
 491                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 492                         num_complete++;
 493                 } else {
 494                         break;
 495                 }
 496         }
 497
 498         /* Every completed frame needs to be acknowledged */
 499         if (num_complete) {
 500                 /*
 501                  * If we've wrapped, we have to clear
 502                  * the results in 2 steps.
 503                  */
 504                 if (result_index > wl->next_tx_complete) {
 505                         /* Only 1 write is needed */
 506                         wl1251_mem_write(wl,
 507                                          wl->data_path->tx_complete_addr +
 508                                          (wl->next_tx_complete *
 509                                           sizeof(struct tx_result)),
 510                                          &result[wl->next_tx_complete],
 511                                          num_complete *
 512                                          sizeof(struct tx_result));
 513
 514
 515                 } else if (result_index < wl->next_tx_complete) {
 516                         /* 2 writes are needed */
 517                         wl1251_mem_write(wl,
 518                                          wl->data_path->tx_complete_addr +
 519                                          (wl->next_tx_complete *
 520                                           sizeof(struct tx_result)),
 521                                          &result[wl->next_tx_complete],
 522                                          (FW_TX_CMPLT_BLOCK_SIZE -
 523                                           wl->next_tx_complete) *
 524                                          sizeof(struct tx_result));
 525
 526                         wl1251_mem_write(wl,
 527                                          wl->data_path->tx_complete_addr,
 528                                          result,
 529                                          (num_complete -
 530                                           FW_TX_CMPLT_BLOCK_SIZE +
 531                                           wl->next_tx_complete) *
 532                                          sizeof(struct tx_result));
 533
 534                 } else {
 535                         /* We have to write the whole array */
 536                         wl1251_mem_write(wl,
 537                                          wl->data_path->tx_complete_addr,
 538                                          result,
 539                                          FW_TX_CMPLT_BLOCK_SIZE *
 540                                          sizeof(struct tx_result));
 541                 }
 542
 543         }
 544
 545         wl->next_tx_complete = result_index;
 546
 547         queue_len = skb_queue_len(&wl->tx_queue);
 548         if (queue_len > 0) {
 549                 /* avoid stalling tx */
 550                 wl1251_tx_work_unlocked(wl, false);
 551                 queue_len = skb_queue_len(&wl->tx_queue);
 552         }
 553
 554         if (queue_len > 0) {
 555                 /* still something to send? Schedule for later */
 556                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 557                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 558         }
 559
 560         if (wl->tx_queue_stopped &&
 561             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 562                 /* tx_queue has space, restart queues */
 563                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 564                 spin_lock_irqsave(&wl->wl_lock, flags);
 565                 ieee80211_wake_queues(wl->hw);
 566                 wl->tx_queue_stopped = false;
 567                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 568         }
 569 }
 570
 571 /* caller must hold wl->mutex */
 572 void wl1251_tx_flush(struct wl1251 *wl)
 573 {
 574         int i;
 575         struct sk_buff *skb;
 576         struct ieee80211_tx_info *info;
 577
 578         /* TX failure */
 579 /*      control->flags = 0; FIXME */
 580
 581         while ((skb = skb_dequeue(&wl->tx_queue))) {
 582                 info = IEEE80211_SKB_CB(skb);
 583
 584                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 585
 586                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 587                                 continue;
 588
 589                 ieee80211_tx_status(wl->hw, skb);
 590         }
 591
 592         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 593                 if (wl->tx_frames[i] != NULL) {
 594                         skb = wl->tx_frames[i];
 595                         info = IEEE80211_SKB_CB(skb);
 596
 597                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 598                                 continue;
 599
 600                         ieee80211_tx_status(wl->hw, skb);
 601                         wl->tx_frames[i] = NULL;
 602                 }
 603 }