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