drivers/net/wireless/wl12xx/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  * Contact: Kalle Valo <kalle.valo@nokia.com>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * version 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  *
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27
  28 #include "wl1251.h"
  29 #include "wl1251_reg.h"
  30 #include "wl1251_tx.h"
  31 #include "wl1251_ps.h"
  32 #include "wl1251_io.h"
  33
  34 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  35 {
  36         int used, data_in_count;
  37
  38         data_in_count = wl->data_in_count;
  39
  40         if (data_in_count < data_out_count)
  41                 /* data_in_count has wrapped */
  42                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  43
  44         used = data_in_count - data_out_count;
  45
  46         WARN_ON(used < 0);
  47         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  48
  49         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  50                 return true;
  51         else
  52                 return false;
  53 }
  54
  55 static int wl1251_tx_path_status(struct wl1251 *wl)
  56 {
  57         u32 status, addr, data_out_count;
  58         bool busy;
  59
  60         addr = wl->data_path->tx_control_addr;
  61         status = wl1251_mem_read32(wl, addr);
  62         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  63         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  64
  65         if (busy)
  66                 return -EBUSY;
  67
  68         return 0;
  69 }
  70
  71 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  72 {
  73         int i;
  74
  75         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  76                 if (wl->tx_frames[i] == NULL) {
  77                         wl->tx_frames[i] = skb;
  78                         return i;
  79                 }
  80
  81         return -EBUSY;
  82 }
  83
  84 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  85                               struct ieee80211_tx_info *control, u16 fc)
  86 {
  87         *(u16 *)&tx_hdr->control = 0;
  88
  89         tx_hdr->control.rate_policy = 0;
  90
  91         /* 802.11 packets */
  92         tx_hdr->control.packet_type = 0;
  93
  94         if (control->flags & IEEE80211_TX_CTL_NO_ACK)
  95                 tx_hdr->control.ack_policy = 1;
  96
  97         tx_hdr->control.tx_complete = 1;
  98
  99         if ((fc & IEEE80211_FTYPE_DATA) &&
 100             ((fc & IEEE80211_STYPE_QOS_DATA) ||
 101              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
 102                 tx_hdr->control.qos = 1;
 103 }
 104
 105 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
 106 #define MAX_MSDU_SECURITY_LENGTH      16
 107 #define MAX_MPDU_SECURITY_LENGTH      16
 108 #define WLAN_QOS_HDR_LEN              26
 109 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
 110                                        WLAN_QOS_HDR_LEN)
 111 #define HW_BLOCK_SIZE                 252
 112 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 113 {
 114         u16 payload_len, frag_threshold, mem_blocks;
 115         u16 num_mpdus, mem_blocks_per_frag;
 116
 117         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 118         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 119
 120         payload_len = tx_hdr->length + MAX_MSDU_SECURITY_LENGTH;
 121
 122         if (payload_len > frag_threshold) {
 123                 mem_blocks_per_frag =
 124                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 125                          HW_BLOCK_SIZE) + 1;
 126                 num_mpdus = payload_len / frag_threshold;
 127                 mem_blocks = num_mpdus * mem_blocks_per_frag;
 128                 payload_len -= num_mpdus * frag_threshold;
 129                 num_mpdus++;
 130
 131         } else {
 132                 mem_blocks_per_frag = 0;
 133                 mem_blocks = 0;
 134                 num_mpdus = 1;
 135         }
 136
 137         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 138
 139         if (num_mpdus > 1)
 140                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 141
 142         tx_hdr->num_mem_blocks = mem_blocks;
 143 }
 144
 145 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 146                               struct ieee80211_tx_info *control)
 147 {
 148         struct tx_double_buffer_desc *tx_hdr;
 149         struct ieee80211_rate *rate;
 150         int id;
 151         u16 fc;
 152
 153         if (!skb)
 154                 return -EINVAL;
 155
 156         id = wl1251_tx_id(wl, skb);
 157         if (id < 0)
 158                 return id;
 159
 160         fc = *(u16 *)skb->data;
 161         tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
 162                                                            sizeof(*tx_hdr));
 163
 164         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 165         rate = ieee80211_get_tx_rate(wl->hw, control);
 166         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 167         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 168         tx_hdr->id = id;
 169
 170         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 171
 172         wl1251_tx_control(tx_hdr, control, fc);
 173         wl1251_tx_frag_block_num(tx_hdr);
 174
 175         return 0;
 176 }
 177
 178 /* We copy the packet to the target */
 179 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 180                                  struct ieee80211_tx_info *control)
 181 {
 182         struct tx_double_buffer_desc *tx_hdr;
 183         int len;
 184         u32 addr;
 185
 186         if (!skb)
 187                 return -EINVAL;
 188
 189         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 190
 191         if (control->control.hw_key &&
 192             control->control.hw_key->alg == ALG_TKIP) {
 193                 int hdrlen;
 194                 u16 fc;
 195                 u8 *pos;
 196
 197                 fc = *(u16 *)(skb->data + sizeof(*tx_hdr));
 198                 tx_hdr->length += WL1251_TKIP_IV_SPACE;
 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                         /* firmware buffer is full, stop queues */
 324                         wl1251_debug(DEBUG_TX, "tx_work: fw buffer full, "
 325                                      "stop queues");
 326                         ieee80211_stop_queues(wl->hw);
 327                         wl->tx_queue_stopped = true;
 328                         skb_queue_head(&wl->tx_queue, skb);
 329                         goto out;
 330                 } else if (ret < 0) {
 331                         dev_kfree_skb(skb);
 332                         goto out;
 333                 }
 334         }
 335
 336 out:
 337         if (woken_up)
 338                 wl1251_ps_elp_sleep(wl);
 339
 340         mutex_unlock(&wl->mutex);
 341 }
 342
 343 static const char *wl1251_tx_parse_status(u8 status)
 344 {
 345         /* 8 bit status field, one character per bit plus null */
 346         static char buf[9];
 347         int i = 0;
 348
 349         memset(buf, 0, sizeof(buf));
 350
 351         if (status & TX_DMA_ERROR)
 352                 buf[i++] = 'm';
 353         if (status & TX_DISABLED)
 354                 buf[i++] = 'd';
 355         if (status & TX_RETRY_EXCEEDED)
 356                 buf[i++] = 'r';
 357         if (status & TX_TIMEOUT)
 358                 buf[i++] = 't';
 359         if (status & TX_KEY_NOT_FOUND)
 360                 buf[i++] = 'k';
 361         if (status & TX_ENCRYPT_FAIL)
 362                 buf[i++] = 'e';
 363         if (status & TX_UNAVAILABLE_PRIORITY)
 364                 buf[i++] = 'p';
 365
 366         /* bit 0 is unused apparently */
 367
 368         return buf;
 369 }
 370
 371 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 372                                 struct tx_result *result)
 373 {
 374         struct ieee80211_tx_info *info;
 375         struct sk_buff *skb;
 376         int hdrlen, ret;
 377         u8 *frame;
 378
 379         skb = wl->tx_frames[result->id];
 380         if (skb == NULL) {
 381                 wl1251_error("SKB for packet %d is NULL", result->id);
 382                 return;
 383         }
 384
 385         info = IEEE80211_SKB_CB(skb);
 386
 387         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 388             (result->status == TX_SUCCESS))
 389                 info->flags |= IEEE80211_TX_STAT_ACK;
 390
 391         info->status.rates[0].count = result->ack_failures + 1;
 392         wl->stats.retry_count += result->ack_failures;
 393
 394         /*
 395          * We have to remove our private TX header before pushing
 396          * the skb back to mac80211.
 397          */
 398         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 399         if (info->control.hw_key &&
 400             info->control.hw_key->alg == ALG_TKIP) {
 401                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 402                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 403                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 404         }
 405
 406         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 407                      " status 0x%x (%s)",
 408                      result->id, skb, result->ack_failures, result->rate,
 409                      result->status, wl1251_tx_parse_status(result->status));
 410
 411
 412         ieee80211_tx_status(wl->hw, skb);
 413
 414         wl->tx_frames[result->id] = NULL;
 415
 416         if (wl->tx_queue_stopped) {
 417                 wl1251_debug(DEBUG_TX, "cb: queue was stopped");
 418
 419                 skb = skb_dequeue(&wl->tx_queue);
 420
 421                 /* The skb can be NULL because tx_work might have been
 422                    scheduled before the queue was stopped making the
 423                    queue empty */
 424
 425                 if (skb) {
 426                         ret = wl1251_tx_frame(wl, skb);
 427                         if (ret == -EBUSY) {
 428                                 /* firmware buffer is still full */
 429                                 wl1251_debug(DEBUG_TX, "cb: fw buffer "
 430                                              "still full");
 431                                 skb_queue_head(&wl->tx_queue, skb);
 432                                 return;
 433                         } else if (ret < 0) {
 434                                 dev_kfree_skb(skb);
 435                                 return;
 436                         }
 437                 }
 438
 439                 wl1251_debug(DEBUG_TX, "cb: waking queues");
 440                 ieee80211_wake_queues(wl->hw);
 441                 wl->tx_queue_stopped = false;
 442         }
 443 }
 444
 445 /* Called upon reception of a TX complete interrupt */
 446 void wl1251_tx_complete(struct wl1251 *wl)
 447 {
 448         int i, result_index, num_complete = 0;
 449         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 450
 451         if (unlikely(wl->state != WL1251_STATE_ON))
 452                 return;
 453
 454         /* First we read the result */
 455         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 456                             result, sizeof(result));
 457
 458         result_index = wl->next_tx_complete;
 459
 460         for (i = 0; i < ARRAY_SIZE(result); i++) {
 461                 result_ptr = &result[result_index];
 462
 463                 if (result_ptr->done_1 == 1 &&
 464                     result_ptr->done_2 == 1) {
 465                         wl1251_tx_packet_cb(wl, result_ptr);
 466
 467                         result_ptr->done_1 = 0;
 468                         result_ptr->done_2 = 0;
 469
 470                         result_index = (result_index + 1) &
 471                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 472                         num_complete++;
 473                 } else {
 474                         break;
 475                 }
 476         }
 477
 478         /* Every completed frame needs to be acknowledged */
 479         if (num_complete) {
 480                 /*
 481                  * If we've wrapped, we have to clear
 482                  * the results in 2 steps.
 483                  */
 484                 if (result_index > wl->next_tx_complete) {
 485                         /* Only 1 write is needed */
 486                         wl1251_mem_write(wl,
 487                                          wl->data_path->tx_complete_addr +
 488                                          (wl->next_tx_complete *
 489                                           sizeof(struct tx_result)),
 490                                          &result[wl->next_tx_complete],
 491                                          num_complete *
 492                                          sizeof(struct tx_result));
 493
 494
 495                 } else if (result_index < wl->next_tx_complete) {
 496                         /* 2 writes are needed */
 497                         wl1251_mem_write(wl,
 498                                          wl->data_path->tx_complete_addr +
 499                                          (wl->next_tx_complete *
 500                                           sizeof(struct tx_result)),
 501                                          &result[wl->next_tx_complete],
 502                                          (FW_TX_CMPLT_BLOCK_SIZE -
 503                                           wl->next_tx_complete) *
 504                                          sizeof(struct tx_result));
 505
 506                         wl1251_mem_write(wl,
 507                                          wl->data_path->tx_complete_addr,
 508                                          result,
 509                                          (num_complete -
 510                                           FW_TX_CMPLT_BLOCK_SIZE +
 511                                           wl->next_tx_complete) *
 512                                          sizeof(struct tx_result));
 513
 514                 } else {
 515                         /* We have to write the whole array */
 516                         wl1251_mem_write(wl,
 517                                          wl->data_path->tx_complete_addr,
 518                                          result,
 519                                          FW_TX_CMPLT_BLOCK_SIZE *
 520                                          sizeof(struct tx_result));
 521                 }
 522
 523         }
 524
 525         wl->next_tx_complete = result_index;
 526 }
 527
 528 /* caller must hold wl->mutex */
 529 void wl1251_tx_flush(struct wl1251 *wl)
 530 {
 531         int i;
 532         struct sk_buff *skb;
 533         struct ieee80211_tx_info *info;
 534
 535         /* TX failure */
 536 /*      control->flags = 0; FIXME */
 537
 538         while ((skb = skb_dequeue(&wl->tx_queue))) {
 539                 info = IEEE80211_SKB_CB(skb);
 540
 541                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 542
 543                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 544                                 continue;
 545
 546                 ieee80211_tx_status(wl->hw, skb);
 547         }
 548
 549         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 550                 if (wl->tx_frames[i] != NULL) {
 551                         skb = wl->tx_frames[i];
 552                         info = IEEE80211_SKB_CB(skb);
 553
 554                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 555                                 continue;
 556
 557                         ieee80211_tx_status(wl->hw, skb);
 558                         wl->tx_frames[i] = NULL;
 559                 }
 560 }