drivers/net/wireless/ti/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 static 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 = skb_push(skb, sizeof(*tx_hdr));
 165
 166         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 167         rate = ieee80211_get_tx_rate(wl->hw, control);
 168         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 169         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 170         tx_hdr->id = id;
 171
 172         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 173
 174         wl1251_tx_control(tx_hdr, control, fc);
 175         wl1251_tx_frag_block_num(tx_hdr);
 176
 177         return 0;
 178 }
 179
 180 /* We copy the packet to the target */
 181 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 182                                  struct ieee80211_tx_info *control)
 183 {
 184         struct tx_double_buffer_desc *tx_hdr;
 185         int len;
 186         u32 addr;
 187
 188         if (!skb)
 189                 return -EINVAL;
 190
 191         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 192
 193         if (control->control.hw_key &&
 194             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 195                 int hdrlen;
 196                 __le16 fc;
 197                 u16 length;
 198                 u8 *pos;
 199
 200                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 201                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 202                 tx_hdr->length = cpu_to_le16(length);
 203
 204                 hdrlen = ieee80211_hdrlen(fc);
 205
 206                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 207                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 208                         sizeof(*tx_hdr) + hdrlen);
 209         }
 210
 211         /* Revisit. This is a workaround for getting non-aligned packets.
 212            This happens at least with EAPOL packets from the user space.
 213            Our DMA requires packets to be aligned on a 4-byte boundary.
 214         */
 215         if (unlikely((long)skb->data & 0x03)) {
 216                 int offset = (4 - (long)skb->data) & 0x03;
 217                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 218
 219                 /* check whether the current skb can be used */
 220                 if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 221                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 222                                                                  GFP_KERNEL);
 223
 224                         if (unlikely(newskb == NULL)) {
 225                                 wl1251_error("Can't allocate skb!");
 226                                 return -EINVAL;
 227                         }
 228
 229                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 230
 231                         dev_kfree_skb_any(skb);
 232                         wl->tx_frames[tx_hdr->id] = skb = newskb;
 233
 234                         offset = (4 - (long)skb->data) & 0x03;
 235                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 236                 }
 237
 238                 /* align the buffer on a 4-byte boundary */
 239                 if (offset) {
 240                         unsigned char *src = skb->data;
 241                         skb_reserve(skb, offset);
 242                         memmove(skb->data, src, skb->len);
 243                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 244                 }
 245         }
 246
 247         /* Our skb->data at this point includes the HW header */
 248         len = WL1251_TX_ALIGN(skb->len);
 249
 250         if (wl->data_in_count & 0x1)
 251                 addr = wl->data_path->tx_packet_ring_addr +
 252                         wl->data_path->tx_packet_ring_chunk_size;
 253         else
 254                 addr = wl->data_path->tx_packet_ring_addr;
 255
 256         wl1251_mem_write(wl, addr, skb->data, len);
 257
 258         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 259                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 260                      tx_hdr->rate, tx_hdr->xmit_queue);
 261
 262         return 0;
 263 }
 264
 265 static void wl1251_tx_trigger(struct wl1251 *wl)
 266 {
 267         u32 data, addr;
 268
 269         if (wl->data_in_count & 0x1) {
 270                 addr = ACX_REG_INTERRUPT_TRIG_H;
 271                 data = INTR_TRIG_TX_PROC1;
 272         } else {
 273                 addr = ACX_REG_INTERRUPT_TRIG;
 274                 data = INTR_TRIG_TX_PROC0;
 275         }
 276
 277         wl1251_reg_write32(wl, addr, data);
 278
 279         /* Bumping data in */
 280         wl->data_in_count = (wl->data_in_count + 1) &
 281                 TX_STATUS_DATA_OUT_COUNT_MASK;
 282 }
 283
 284 static void enable_tx_for_packet_injection(struct wl1251 *wl)
 285 {
 286         int ret;
 287
 288         ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
 289                               wl->beacon_int, wl->dtim_period);
 290         if (ret < 0) {
 291                 wl1251_warning("join failed");
 292                 return;
 293         }
 294
 295         ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
 296         if (ret < 0) {
 297                 wl1251_warning("join timeout");
 298                 return;
 299         }
 300
 301         wl->joined = true;
 302 }
 303
 304 /* caller must hold wl->mutex */
 305 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 306 {
 307         struct ieee80211_tx_info *info;
 308         int ret = 0;
 309         u8 idx;
 310
 311         info = IEEE80211_SKB_CB(skb);
 312
 313         if (info->control.hw_key) {
 314                 if (unlikely(wl->monitor_present))
 315                         return -EINVAL;
 316
 317                 idx = info->control.hw_key->hw_key_idx;
 318                 if (unlikely(wl->default_key != idx)) {
 319                         ret = wl1251_acx_default_key(wl, idx);
 320                         if (ret < 0)
 321                                 return ret;
 322                 }
 323         }
 324
 325         /* Enable tx path in monitor mode for packet injection */
 326         if ((wl->vif == NULL) && !wl->joined)
 327                 enable_tx_for_packet_injection(wl);
 328
 329         ret = wl1251_tx_path_status(wl);
 330         if (ret < 0)
 331                 return ret;
 332
 333         ret = wl1251_tx_fill_hdr(wl, skb, info);
 334         if (ret < 0)
 335                 return ret;
 336
 337         ret = wl1251_tx_send_packet(wl, skb, info);
 338         if (ret < 0)
 339                 return ret;
 340
 341         wl1251_tx_trigger(wl);
 342
 343         return ret;
 344 }
 345
 346 void wl1251_tx_work(struct work_struct *work)
 347 {
 348         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 349         struct sk_buff *skb;
 350         bool woken_up = false;
 351         int ret;
 352
 353         mutex_lock(&wl->mutex);
 354
 355         if (unlikely(wl->state == WL1251_STATE_OFF))
 356                 goto out;
 357
 358         while ((skb = skb_dequeue(&wl->tx_queue))) {
 359                 if (!woken_up) {
 360                         ret = wl1251_ps_elp_wakeup(wl);
 361                         if (ret < 0)
 362                                 goto out;
 363                         woken_up = true;
 364                 }
 365
 366                 ret = wl1251_tx_frame(wl, skb);
 367                 if (ret == -EBUSY) {
 368                         skb_queue_head(&wl->tx_queue, skb);
 369                         goto out;
 370                 } else if (ret < 0) {
 371                         dev_kfree_skb(skb);
 372                         goto out;
 373                 }
 374         }
 375
 376 out:
 377         if (woken_up)
 378                 wl1251_ps_elp_sleep(wl);
 379
 380         mutex_unlock(&wl->mutex);
 381 }
 382
 383 static const char *wl1251_tx_parse_status(u8 status)
 384 {
 385         /* 8 bit status field, one character per bit plus null */
 386         static char buf[9];
 387         int i = 0;
 388
 389         memset(buf, 0, sizeof(buf));
 390
 391         if (status & TX_DMA_ERROR)
 392                 buf[i++] = 'm';
 393         if (status & TX_DISABLED)
 394                 buf[i++] = 'd';
 395         if (status & TX_RETRY_EXCEEDED)
 396                 buf[i++] = 'r';
 397         if (status & TX_TIMEOUT)
 398                 buf[i++] = 't';
 399         if (status & TX_KEY_NOT_FOUND)
 400                 buf[i++] = 'k';
 401         if (status & TX_ENCRYPT_FAIL)
 402                 buf[i++] = 'e';
 403         if (status & TX_UNAVAILABLE_PRIORITY)
 404                 buf[i++] = 'p';
 405
 406         /* bit 0 is unused apparently */
 407
 408         return buf;
 409 }
 410
 411 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 412                                 struct tx_result *result)
 413 {
 414         struct ieee80211_tx_info *info;
 415         struct sk_buff *skb;
 416         int hdrlen;
 417         u8 *frame;
 418
 419         skb = wl->tx_frames[result->id];
 420         if (skb == NULL) {
 421                 wl1251_error("SKB for packet %d is NULL", result->id);
 422                 return;
 423         }
 424
 425         info = IEEE80211_SKB_CB(skb);
 426
 427         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 428             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 429             (result->status == TX_SUCCESS))
 430                 info->flags |= IEEE80211_TX_STAT_ACK;
 431
 432         info->status.rates[0].count = result->ack_failures + 1;
 433         wl->stats.retry_count += result->ack_failures;
 434
 435         /*
 436          * We have to remove our private TX header before pushing
 437          * the skb back to mac80211.
 438          */
 439         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 440         if (info->control.hw_key &&
 441             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 442                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 443                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 444                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 445         }
 446
 447         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 448                      " status 0x%x (%s)",
 449                      result->id, skb, result->ack_failures, result->rate,
 450                      result->status, wl1251_tx_parse_status(result->status));
 451
 452
 453         ieee80211_tx_status(wl->hw, skb);
 454
 455         wl->tx_frames[result->id] = NULL;
 456 }
 457
 458 /* Called upon reception of a TX complete interrupt */
 459 void wl1251_tx_complete(struct wl1251 *wl)
 460 {
 461         int i, result_index, num_complete = 0, queue_len;
 462         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 463         unsigned long flags;
 464
 465         if (unlikely(wl->state != WL1251_STATE_ON))
 466                 return;
 467
 468         /* First we read the result */
 469         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 470                             result, sizeof(result));
 471
 472         result_index = wl->next_tx_complete;
 473
 474         for (i = 0; i < ARRAY_SIZE(result); i++) {
 475                 result_ptr = &result[result_index];
 476
 477                 if (result_ptr->done_1 == 1 &&
 478                     result_ptr->done_2 == 1) {
 479                         wl1251_tx_packet_cb(wl, result_ptr);
 480
 481                         result_ptr->done_1 = 0;
 482                         result_ptr->done_2 = 0;
 483
 484                         result_index = (result_index + 1) &
 485                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 486                         num_complete++;
 487                 } else {
 488                         break;
 489                 }
 490         }
 491
 492         queue_len = skb_queue_len(&wl->tx_queue);
 493
 494         if ((num_complete > 0) && (queue_len > 0)) {
 495                 /* firmware buffer has space, reschedule tx_work */
 496                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 497                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 498         }
 499
 500         if (wl->tx_queue_stopped &&
 501             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 502                 /* tx_queue has space, restart queues */
 503                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 504                 spin_lock_irqsave(&wl->wl_lock, flags);
 505                 ieee80211_wake_queues(wl->hw);
 506                 wl->tx_queue_stopped = false;
 507                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 508         }
 509
 510         /* Every completed frame needs to be acknowledged */
 511         if (num_complete) {
 512                 /*
 513                  * If we've wrapped, we have to clear
 514                  * the results in 2 steps.
 515                  */
 516                 if (result_index > wl->next_tx_complete) {
 517                         /* Only 1 write is needed */
 518                         wl1251_mem_write(wl,
 519                                          wl->data_path->tx_complete_addr +
 520                                          (wl->next_tx_complete *
 521                                           sizeof(struct tx_result)),
 522                                          &result[wl->next_tx_complete],
 523                                          num_complete *
 524                                          sizeof(struct tx_result));
 525
 526
 527                 } else if (result_index < wl->next_tx_complete) {
 528                         /* 2 writes are needed */
 529                         wl1251_mem_write(wl,
 530                                          wl->data_path->tx_complete_addr +
 531                                          (wl->next_tx_complete *
 532                                           sizeof(struct tx_result)),
 533                                          &result[wl->next_tx_complete],
 534                                          (FW_TX_CMPLT_BLOCK_SIZE -
 535                                           wl->next_tx_complete) *
 536                                          sizeof(struct tx_result));
 537
 538                         wl1251_mem_write(wl,
 539                                          wl->data_path->tx_complete_addr,
 540                                          result,
 541                                          (num_complete -
 542                                           FW_TX_CMPLT_BLOCK_SIZE +
 543                                           wl->next_tx_complete) *
 544                                          sizeof(struct tx_result));
 545
 546                 } else {
 547                         /* We have to write the whole array */
 548                         wl1251_mem_write(wl,
 549                                          wl->data_path->tx_complete_addr,
 550                                          result,
 551                                          FW_TX_CMPLT_BLOCK_SIZE *
 552                                          sizeof(struct tx_result));
 553                 }
 554
 555         }
 556
 557         wl->next_tx_complete = result_index;
 558 }
 559
 560 /* caller must hold wl->mutex */
 561 void wl1251_tx_flush(struct wl1251 *wl)
 562 {
 563         int i;
 564         struct sk_buff *skb;
 565         struct ieee80211_tx_info *info;
 566
 567         /* TX failure */
 568 /*      control->flags = 0; FIXME */
 569
 570         while ((skb = skb_dequeue(&wl->tx_queue))) {
 571                 info = IEEE80211_SKB_CB(skb);
 572
 573                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 574
 575                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 576                                 continue;
 577
 578                 ieee80211_tx_status(wl->hw, skb);
 579         }
 580
 581         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 582                 if (wl->tx_frames[i] != NULL) {
 583                         skb = wl->tx_frames[i];
 584                         info = IEEE80211_SKB_CB(skb);
 585
 586                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 587                                 continue;
 588
 589                         ieee80211_tx_status(wl->hw, skb);
 590                         wl->tx_frames[i] = NULL;
 591                 }
 592 }