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
  32 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  33 {
  34         int used, data_in_count;
  35
  36         data_in_count = wl->data_in_count;
  37
  38         if (data_in_count < data_out_count)
  39                 /* data_in_count has wrapped */
  40                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  41
  42         used = data_in_count - data_out_count;
  43
  44         WARN_ON(used < 0);
  45         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  46
  47         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  48                 return true;
  49         else
  50                 return false;
  51 }
  52
  53 static int wl1251_tx_path_status(struct wl1251 *wl)
  54 {
  55         u32 status, addr, data_out_count;
  56         bool busy;
  57
  58         addr = wl->data_path->tx_control_addr;
  59         status = wl1251_mem_read32(wl, addr);
  60         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  61         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  62
  63         if (busy)
  64                 return -EBUSY;
  65
  66         return 0;
  67 }
  68
  69 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  70 {
  71         int i;
  72
  73         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  74                 if (wl->tx_frames[i] == NULL) {
  75                         wl->tx_frames[i] = skb;
  76                         return i;
  77                 }
  78
  79         return -EBUSY;
  80 }
  81
  82 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  83                               struct ieee80211_tx_info *control, u16 fc)
  84 {
  85         *(u16 *)&tx_hdr->control = 0;
  86
  87         tx_hdr->control.rate_policy = 0;
  88
  89         /* 802.11 packets */
  90         tx_hdr->control.packet_type = 0;
  91
  92         if (control->flags & IEEE80211_TX_CTL_NO_ACK)
  93                 tx_hdr->control.ack_policy = 1;
  94
  95         tx_hdr->control.tx_complete = 1;
  96
  97         if ((fc & IEEE80211_FTYPE_DATA) &&
  98             ((fc & IEEE80211_STYPE_QOS_DATA) ||
  99              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
 100                 tx_hdr->control.qos = 1;
 101 }
 102
 103 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
 104 #define MAX_MSDU_SECURITY_LENGTH      16
 105 #define MAX_MPDU_SECURITY_LENGTH      16
 106 #define WLAN_QOS_HDR_LEN              26
 107 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
 108                                        WLAN_QOS_HDR_LEN)
 109 #define HW_BLOCK_SIZE                 252
 110 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 111 {
 112         u16 payload_len, frag_threshold, mem_blocks;
 113         u16 num_mpdus, mem_blocks_per_frag;
 114
 115         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 116         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 117
 118         payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 119
 120         if (payload_len > frag_threshold) {
 121                 mem_blocks_per_frag =
 122                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 123                          HW_BLOCK_SIZE) + 1;
 124                 num_mpdus = payload_len / frag_threshold;
 125                 mem_blocks = num_mpdus * mem_blocks_per_frag;
 126                 payload_len -= num_mpdus * frag_threshold;
 127                 num_mpdus++;
 128
 129         } else {
 130                 mem_blocks_per_frag = 0;
 131                 mem_blocks = 0;
 132                 num_mpdus = 1;
 133         }
 134
 135         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 136
 137         if (num_mpdus > 1)
 138                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 139
 140         tx_hdr->num_mem_blocks = mem_blocks;
 141 }
 142
 143 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 144                               struct ieee80211_tx_info *control)
 145 {
 146         struct tx_double_buffer_desc *tx_hdr;
 147         struct ieee80211_rate *rate;
 148         int id;
 149         u16 fc;
 150
 151         if (!skb)
 152                 return -EINVAL;
 153
 154         id = wl1251_tx_id(wl, skb);
 155         if (id < 0)
 156                 return id;
 157
 158         fc = *(u16 *)skb->data;
 159         tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
 160                                                            sizeof(*tx_hdr));
 161
 162         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 163         rate = ieee80211_get_tx_rate(wl->hw, control);
 164         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 165         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 166         tx_hdr->id = id;
 167
 168         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 169
 170         wl1251_tx_control(tx_hdr, control, fc);
 171         wl1251_tx_frag_block_num(tx_hdr);
 172
 173         return 0;
 174 }
 175
 176 /* We copy the packet to the target */
 177 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 178                                  struct ieee80211_tx_info *control)
 179 {
 180         struct tx_double_buffer_desc *tx_hdr;
 181         int len;
 182         u32 addr;
 183
 184         if (!skb)
 185                 return -EINVAL;
 186
 187         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 188
 189         if (control->control.hw_key &&
 190             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 191                 int hdrlen;
 192                 __le16 fc;
 193                 u16 length;
 194                 u8 *pos;
 195
 196                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 197                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 198                 tx_hdr->length = cpu_to_le16(length);
 199
 200                 hdrlen = ieee80211_hdrlen(fc);
 201
 202                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 203                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 204                         sizeof(*tx_hdr) + hdrlen);
 205         }
 206
 207         /* Revisit. This is a workaround for getting non-aligned packets.
 208            This happens at least with EAPOL packets from the user space.
 209            Our DMA requires packets to be aligned on a 4-byte boundary.
 210         */
 211         if (unlikely((long)skb->data & 0x03)) {
 212                 int offset = (4 - (long)skb->data) & 0x03;
 213                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 214
 215                 /* check whether the current skb can be used */
 216                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 217                         unsigned char *src = skb->data;
 218
 219                         /* align the buffer on a 4-byte boundary */
 220                         skb_reserve(skb, offset);
 221                         memmove(skb->data, src, skb->len);
 222                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 223                 } else {
 224                         wl1251_info("No handler, fixme!");
 225                         return -EINVAL;
 226                 }
 227         }
 228
 229         /* Our skb->data at this point includes the HW header */
 230         len = WL1251_TX_ALIGN(skb->len);
 231
 232         if (wl->data_in_count & 0x1)
 233                 addr = wl->data_path->tx_packet_ring_addr +
 234                         wl->data_path->tx_packet_ring_chunk_size;
 235         else
 236                 addr = wl->data_path->tx_packet_ring_addr;
 237
 238         wl1251_mem_write(wl, addr, skb->data, len);
 239
 240         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 241                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 242                      tx_hdr->rate, tx_hdr->xmit_queue);
 243
 244         return 0;
 245 }
 246
 247 static void wl1251_tx_trigger(struct wl1251 *wl)
 248 {
 249         u32 data, addr;
 250
 251         if (wl->data_in_count & 0x1) {
 252                 addr = ACX_REG_INTERRUPT_TRIG_H;
 253                 data = INTR_TRIG_TX_PROC1;
 254         } else {
 255                 addr = ACX_REG_INTERRUPT_TRIG;
 256                 data = INTR_TRIG_TX_PROC0;
 257         }
 258
 259         wl1251_reg_write32(wl, addr, data);
 260
 261         /* Bumping data in */
 262         wl->data_in_count = (wl->data_in_count + 1) &
 263                 TX_STATUS_DATA_OUT_COUNT_MASK;
 264 }
 265
 266 /* caller must hold wl->mutex */
 267 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 268 {
 269         struct ieee80211_tx_info *info;
 270         int ret = 0;
 271         u8 idx;
 272
 273         info = IEEE80211_SKB_CB(skb);
 274
 275         if (info->control.hw_key) {
 276                 idx = info->control.hw_key->hw_key_idx;
 277                 if (unlikely(wl->default_key != idx)) {
 278                         ret = wl1251_acx_default_key(wl, idx);
 279                         if (ret < 0)
 280                                 return ret;
 281                 }
 282         }
 283
 284         ret = wl1251_tx_path_status(wl);
 285         if (ret < 0)
 286                 return ret;
 287
 288         ret = wl1251_tx_fill_hdr(wl, skb, info);
 289         if (ret < 0)
 290                 return ret;
 291
 292         ret = wl1251_tx_send_packet(wl, skb, info);
 293         if (ret < 0)
 294                 return ret;
 295
 296         wl1251_tx_trigger(wl);
 297
 298         return ret;
 299 }
 300
 301 void wl1251_tx_work(struct work_struct *work)
 302 {
 303         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 304         struct sk_buff *skb;
 305         bool woken_up = false;
 306         int ret;
 307
 308         mutex_lock(&wl->mutex);
 309
 310         if (unlikely(wl->state == WL1251_STATE_OFF))
 311                 goto out;
 312
 313         while ((skb = skb_dequeue(&wl->tx_queue))) {
 314                 if (!woken_up) {
 315                         ret = wl1251_ps_elp_wakeup(wl);
 316                         if (ret < 0)
 317                                 goto out;
 318                         woken_up = true;
 319                 }
 320
 321                 ret = wl1251_tx_frame(wl, skb);
 322                 if (ret == -EBUSY) {
 323                         skb_queue_head(&wl->tx_queue, skb);
 324                         goto out;
 325                 } else if (ret < 0) {
 326                         dev_kfree_skb(skb);
 327                         goto out;
 328                 }
 329         }
 330
 331 out:
 332         if (woken_up)
 333                 wl1251_ps_elp_sleep(wl);
 334
 335         mutex_unlock(&wl->mutex);
 336 }
 337
 338 static const char *wl1251_tx_parse_status(u8 status)
 339 {
 340         /* 8 bit status field, one character per bit plus null */
 341         static char buf[9];
 342         int i = 0;
 343
 344         memset(buf, 0, sizeof(buf));
 345
 346         if (status & TX_DMA_ERROR)
 347                 buf[i++] = 'm';
 348         if (status & TX_DISABLED)
 349                 buf[i++] = 'd';
 350         if (status & TX_RETRY_EXCEEDED)
 351                 buf[i++] = 'r';
 352         if (status & TX_TIMEOUT)
 353                 buf[i++] = 't';
 354         if (status & TX_KEY_NOT_FOUND)
 355                 buf[i++] = 'k';
 356         if (status & TX_ENCRYPT_FAIL)
 357                 buf[i++] = 'e';
 358         if (status & TX_UNAVAILABLE_PRIORITY)
 359                 buf[i++] = 'p';
 360
 361         /* bit 0 is unused apparently */
 362
 363         return buf;
 364 }
 365
 366 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 367                                 struct tx_result *result)
 368 {
 369         struct ieee80211_tx_info *info;
 370         struct sk_buff *skb;
 371         int hdrlen, ret;
 372         u8 *frame;
 373
 374         skb = wl->tx_frames[result->id];
 375         if (skb == NULL) {
 376                 wl1251_error("SKB for packet %d is NULL", result->id);
 377                 return;
 378         }
 379
 380         info = IEEE80211_SKB_CB(skb);
 381
 382         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 383             (result->status == TX_SUCCESS))
 384                 info->flags |= IEEE80211_TX_STAT_ACK;
 385
 386         info->status.rates[0].count = result->ack_failures + 1;
 387         wl->stats.retry_count += result->ack_failures;
 388
 389         /*
 390          * We have to remove our private TX header before pushing
 391          * the skb back to mac80211.
 392          */
 393         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 394         if (info->control.hw_key &&
 395             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 396                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 397                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 398                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 399         }
 400
 401         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 402                      " status 0x%x (%s)",
 403                      result->id, skb, result->ack_failures, result->rate,
 404                      result->status, wl1251_tx_parse_status(result->status));
 405
 406
 407         ieee80211_tx_status(wl->hw, skb);
 408
 409         wl->tx_frames[result->id] = NULL;
 410
 411         if (wl->tx_queue_stopped) {
 412                 wl1251_debug(DEBUG_TX, "cb: queue was stopped");
 413
 414                 skb = skb_dequeue(&wl->tx_queue);
 415
 416                 /* The skb can be NULL because tx_work might have been
 417                    scheduled before the queue was stopped making the
 418                    queue empty */
 419
 420                 if (skb) {
 421                         ret = wl1251_tx_frame(wl, skb);
 422                         if (ret == -EBUSY) {
 423                                 /* firmware buffer is still full */
 424                                 wl1251_debug(DEBUG_TX, "cb: fw buffer "
 425                                              "still full");
 426                                 skb_queue_head(&wl->tx_queue, skb);
 427                                 return;
 428                         } else if (ret < 0) {
 429                                 dev_kfree_skb(skb);
 430                                 return;
 431                         }
 432                 }
 433
 434                 wl1251_debug(DEBUG_TX, "cb: waking queues");
 435                 ieee80211_wake_queues(wl->hw);
 436                 wl->tx_queue_stopped = false;
 437         }
 438 }
 439
 440 /* Called upon reception of a TX complete interrupt */
 441 void wl1251_tx_complete(struct wl1251 *wl)
 442 {
 443         int i, result_index, num_complete = 0;
 444         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 445         unsigned long flags;
 446
 447         if (unlikely(wl->state != WL1251_STATE_ON))
 448                 return;
 449
 450         /* First we read the result */
 451         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 452                             result, sizeof(result));
 453
 454         result_index = wl->next_tx_complete;
 455
 456         for (i = 0; i < ARRAY_SIZE(result); i++) {
 457                 result_ptr = &result[result_index];
 458
 459                 if (result_ptr->done_1 == 1 &&
 460                     result_ptr->done_2 == 1) {
 461                         wl1251_tx_packet_cb(wl, result_ptr);
 462
 463                         result_ptr->done_1 = 0;
 464                         result_ptr->done_2 = 0;
 465
 466                         result_index = (result_index + 1) &
 467                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 468                         num_complete++;
 469                 } else {
 470                         break;
 471                 }
 472         }
 473
 474         if (wl->tx_queue_stopped
 475             &&
 476             skb_queue_len(&wl->tx_queue) <= WL1251_TX_QUEUE_LOW_WATERMARK){
 477
 478                 /* firmware buffer has space, restart queues */
 479                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 480                 spin_lock_irqsave(&wl->wl_lock, flags);
 481                 ieee80211_wake_queues(wl->hw);
 482                 wl->tx_queue_stopped = false;
 483                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 484                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 485
 486         }
 487
 488         /* Every completed frame needs to be acknowledged */
 489         if (num_complete) {
 490                 /*
 491                  * If we've wrapped, we have to clear
 492                  * the results in 2 steps.
 493                  */
 494                 if (result_index > wl->next_tx_complete) {
 495                         /* Only 1 write is needed */
 496                         wl1251_mem_write(wl,
 497                                          wl->data_path->tx_complete_addr +
 498                                          (wl->next_tx_complete *
 499                                           sizeof(struct tx_result)),
 500                                          &result[wl->next_tx_complete],
 501                                          num_complete *
 502                                          sizeof(struct tx_result));
 503
 504
 505                 } else if (result_index < wl->next_tx_complete) {
 506                         /* 2 writes are needed */
 507                         wl1251_mem_write(wl,
 508                                          wl->data_path->tx_complete_addr +
 509                                          (wl->next_tx_complete *
 510                                           sizeof(struct tx_result)),
 511                                          &result[wl->next_tx_complete],
 512                                          (FW_TX_CMPLT_BLOCK_SIZE -
 513                                           wl->next_tx_complete) *
 514                                          sizeof(struct tx_result));
 515
 516                         wl1251_mem_write(wl,
 517                                          wl->data_path->tx_complete_addr,
 518                                          result,
 519                                          (num_complete -
 520                                           FW_TX_CMPLT_BLOCK_SIZE +
 521                                           wl->next_tx_complete) *
 522                                          sizeof(struct tx_result));
 523
 524                 } else {
 525                         /* We have to write the whole array */
 526                         wl1251_mem_write(wl,
 527                                          wl->data_path->tx_complete_addr,
 528                                          result,
 529                                          FW_TX_CMPLT_BLOCK_SIZE *
 530                                          sizeof(struct tx_result));
 531                 }
 532
 533         }
 534
 535         wl->next_tx_complete = result_index;
 536 }
 537
 538 /* caller must hold wl->mutex */
 539 void wl1251_tx_flush(struct wl1251 *wl)
 540 {
 541         int i;
 542         struct sk_buff *skb;
 543         struct ieee80211_tx_info *info;
 544
 545         /* TX failure */
 546 /*      control->flags = 0; FIXME */
 547
 548         while ((skb = skb_dequeue(&wl->tx_queue))) {
 549                 info = IEEE80211_SKB_CB(skb);
 550
 551                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 552
 553                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 554                                 continue;
 555
 556                 ieee80211_tx_status(wl->hw, skb);
 557         }
 558
 559         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 560                 if (wl->tx_frames[i] != NULL) {
 561                         skb = wl->tx_frames[i];
 562                         info = IEEE80211_SKB_CB(skb);
 563
 564                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 565                                 continue;
 566
 567                         ieee80211_tx_status(wl->hw, skb);
 568                         wl->tx_frames[i] = NULL;
 569                 }
 570 }