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 = le16_to_cpu(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                 __le16 fc;
 195                 u16 length;
 196                 u8 *pos;
 197
 198                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 199                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 200                 tx_hdr->length = cpu_to_le16(length);
 201
 202                 hdrlen = ieee80211_hdrlen(fc);
 203
 204                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 205                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 206                         sizeof(*tx_hdr) + hdrlen);
 207         }
 208
 209         /* Revisit. This is a workaround for getting non-aligned packets.
 210            This happens at least with EAPOL packets from the user space.
 211            Our DMA requires packets to be aligned on a 4-byte boundary.
 212         */
 213         if (unlikely((long)skb->data & 0x03)) {
 214                 int offset = (4 - (long)skb->data) & 0x03;
 215                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 216
 217                 /* check whether the current skb can be used */
 218                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 219                         unsigned char *src = skb->data;
 220
 221                         /* align the buffer on a 4-byte boundary */
 222                         skb_reserve(skb, offset);
 223                         memmove(skb->data, src, skb->len);
 224                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 225                 } else {
 226                         wl1251_info("No handler, fixme!");
 227                         return -EINVAL;
 228                 }
 229         }
 230
 231         /* Our skb->data at this point includes the HW header */
 232         len = WL1251_TX_ALIGN(skb->len);
 233
 234         if (wl->data_in_count & 0x1)
 235                 addr = wl->data_path->tx_packet_ring_addr +
 236                         wl->data_path->tx_packet_ring_chunk_size;
 237         else
 238                 addr = wl->data_path->tx_packet_ring_addr;
 239
 240         wl1251_mem_write(wl, addr, skb->data, len);
 241
 242         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 243                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 244                      tx_hdr->rate, tx_hdr->xmit_queue);
 245
 246         return 0;
 247 }
 248
 249 static void wl1251_tx_trigger(struct wl1251 *wl)
 250 {
 251         u32 data, addr;
 252
 253         if (wl->data_in_count & 0x1) {
 254                 addr = ACX_REG_INTERRUPT_TRIG_H;
 255                 data = INTR_TRIG_TX_PROC1;
 256         } else {
 257                 addr = ACX_REG_INTERRUPT_TRIG;
 258                 data = INTR_TRIG_TX_PROC0;
 259         }
 260
 261         wl1251_reg_write32(wl, addr, data);
 262
 263         /* Bumping data in */
 264         wl->data_in_count = (wl->data_in_count + 1) &
 265                 TX_STATUS_DATA_OUT_COUNT_MASK;
 266 }
 267
 268 /* caller must hold wl->mutex */
 269 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 270 {
 271         struct ieee80211_tx_info *info;
 272         int ret = 0;
 273         u8 idx;
 274
 275         info = IEEE80211_SKB_CB(skb);
 276
 277         if (info->control.hw_key) {
 278                 idx = info->control.hw_key->hw_key_idx;
 279                 if (unlikely(wl->default_key != idx)) {
 280                         ret = wl1251_acx_default_key(wl, idx);
 281                         if (ret < 0)
 282                                 return ret;
 283                 }
 284         }
 285
 286         ret = wl1251_tx_path_status(wl);
 287         if (ret < 0)
 288                 return ret;
 289
 290         ret = wl1251_tx_fill_hdr(wl, skb, info);
 291         if (ret < 0)
 292                 return ret;
 293
 294         ret = wl1251_tx_send_packet(wl, skb, info);
 295         if (ret < 0)
 296                 return ret;
 297
 298         wl1251_tx_trigger(wl);
 299
 300         return ret;
 301 }
 302
 303 void wl1251_tx_work(struct work_struct *work)
 304 {
 305         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 306         struct sk_buff *skb;
 307         bool woken_up = false;
 308         int ret;
 309
 310         mutex_lock(&wl->mutex);
 311
 312         if (unlikely(wl->state == WL1251_STATE_OFF))
 313                 goto out;
 314
 315         while ((skb = skb_dequeue(&wl->tx_queue))) {
 316                 if (!woken_up) {
 317                         ret = wl1251_ps_elp_wakeup(wl);
 318                         if (ret < 0)
 319                                 goto out;
 320                         woken_up = true;
 321                 }
 322
 323                 ret = wl1251_tx_frame(wl, skb);
 324                 if (ret == -EBUSY) {
 325                         /* firmware buffer is full, stop queues */
 326                         wl1251_debug(DEBUG_TX, "tx_work: fw buffer full, "
 327                                      "stop queues");
 328                         ieee80211_stop_queues(wl->hw);
 329                         wl->tx_queue_stopped = true;
 330                         skb_queue_head(&wl->tx_queue, skb);
 331                         goto out;
 332                 } else if (ret < 0) {
 333                         dev_kfree_skb(skb);
 334                         goto out;
 335                 }
 336         }
 337
 338 out:
 339         if (woken_up)
 340                 wl1251_ps_elp_sleep(wl);
 341
 342         mutex_unlock(&wl->mutex);
 343 }
 344
 345 static const char *wl1251_tx_parse_status(u8 status)
 346 {
 347         /* 8 bit status field, one character per bit plus null */
 348         static char buf[9];
 349         int i = 0;
 350
 351         memset(buf, 0, sizeof(buf));
 352
 353         if (status & TX_DMA_ERROR)
 354                 buf[i++] = 'm';
 355         if (status & TX_DISABLED)
 356                 buf[i++] = 'd';
 357         if (status & TX_RETRY_EXCEEDED)
 358                 buf[i++] = 'r';
 359         if (status & TX_TIMEOUT)
 360                 buf[i++] = 't';
 361         if (status & TX_KEY_NOT_FOUND)
 362                 buf[i++] = 'k';
 363         if (status & TX_ENCRYPT_FAIL)
 364                 buf[i++] = 'e';
 365         if (status & TX_UNAVAILABLE_PRIORITY)
 366                 buf[i++] = 'p';
 367
 368         /* bit 0 is unused apparently */
 369
 370         return buf;
 371 }
 372
 373 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 374                                 struct tx_result *result)
 375 {
 376         struct ieee80211_tx_info *info;
 377         struct sk_buff *skb;
 378         int hdrlen, ret;
 379         u8 *frame;
 380
 381         skb = wl->tx_frames[result->id];
 382         if (skb == NULL) {
 383                 wl1251_error("SKB for packet %d is NULL", result->id);
 384                 return;
 385         }
 386
 387         info = IEEE80211_SKB_CB(skb);
 388
 389         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 390             (result->status == TX_SUCCESS))
 391                 info->flags |= IEEE80211_TX_STAT_ACK;
 392
 393         info->status.rates[0].count = result->ack_failures + 1;
 394         wl->stats.retry_count += result->ack_failures;
 395
 396         /*
 397          * We have to remove our private TX header before pushing
 398          * the skb back to mac80211.
 399          */
 400         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 401         if (info->control.hw_key &&
 402             info->control.hw_key->alg == ALG_TKIP) {
 403                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 404                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 405                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 406         }
 407
 408         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 409                      " status 0x%x (%s)",
 410                      result->id, skb, result->ack_failures, result->rate,
 411                      result->status, wl1251_tx_parse_status(result->status));
 412
 413
 414         ieee80211_tx_status(wl->hw, skb);
 415
 416         wl->tx_frames[result->id] = NULL;
 417
 418         if (wl->tx_queue_stopped) {
 419                 wl1251_debug(DEBUG_TX, "cb: queue was stopped");
 420
 421                 skb = skb_dequeue(&wl->tx_queue);
 422
 423                 /* The skb can be NULL because tx_work might have been
 424                    scheduled before the queue was stopped making the
 425                    queue empty */
 426
 427                 if (skb) {
 428                         ret = wl1251_tx_frame(wl, skb);
 429                         if (ret == -EBUSY) {
 430                                 /* firmware buffer is still full */
 431                                 wl1251_debug(DEBUG_TX, "cb: fw buffer "
 432                                              "still full");
 433                                 skb_queue_head(&wl->tx_queue, skb);
 434                                 return;
 435                         } else if (ret < 0) {
 436                                 dev_kfree_skb(skb);
 437                                 return;
 438                         }
 439                 }
 440
 441                 wl1251_debug(DEBUG_TX, "cb: waking queues");
 442                 ieee80211_wake_queues(wl->hw);
 443                 wl->tx_queue_stopped = false;
 444         }
 445 }
 446
 447 /* Called upon reception of a TX complete interrupt */
 448 void wl1251_tx_complete(struct wl1251 *wl)
 449 {
 450         int i, result_index, num_complete = 0;
 451         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 452
 453         if (unlikely(wl->state != WL1251_STATE_ON))
 454                 return;
 455
 456         /* First we read the result */
 457         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 458                             result, sizeof(result));
 459
 460         result_index = wl->next_tx_complete;
 461
 462         for (i = 0; i < ARRAY_SIZE(result); i++) {
 463                 result_ptr = &result[result_index];
 464
 465                 if (result_ptr->done_1 == 1 &&
 466                     result_ptr->done_2 == 1) {
 467                         wl1251_tx_packet_cb(wl, result_ptr);
 468
 469                         result_ptr->done_1 = 0;
 470                         result_ptr->done_2 = 0;
 471
 472                         result_index = (result_index + 1) &
 473                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 474                         num_complete++;
 475                 } else {
 476                         break;
 477                 }
 478         }
 479
 480         /* Every completed frame needs to be acknowledged */
 481         if (num_complete) {
 482                 /*
 483                  * If we've wrapped, we have to clear
 484                  * the results in 2 steps.
 485                  */
 486                 if (result_index > wl->next_tx_complete) {
 487                         /* Only 1 write is needed */
 488                         wl1251_mem_write(wl,
 489                                          wl->data_path->tx_complete_addr +
 490                                          (wl->next_tx_complete *
 491                                           sizeof(struct tx_result)),
 492                                          &result[wl->next_tx_complete],
 493                                          num_complete *
 494                                          sizeof(struct tx_result));
 495
 496
 497                 } else if (result_index < wl->next_tx_complete) {
 498                         /* 2 writes are needed */
 499                         wl1251_mem_write(wl,
 500                                          wl->data_path->tx_complete_addr +
 501                                          (wl->next_tx_complete *
 502                                           sizeof(struct tx_result)),
 503                                          &result[wl->next_tx_complete],
 504                                          (FW_TX_CMPLT_BLOCK_SIZE -
 505                                           wl->next_tx_complete) *
 506                                          sizeof(struct tx_result));
 507
 508                         wl1251_mem_write(wl,
 509                                          wl->data_path->tx_complete_addr,
 510                                          result,
 511                                          (num_complete -
 512                                           FW_TX_CMPLT_BLOCK_SIZE +
 513                                           wl->next_tx_complete) *
 514                                          sizeof(struct tx_result));
 515
 516                 } else {
 517                         /* We have to write the whole array */
 518                         wl1251_mem_write(wl,
 519                                          wl->data_path->tx_complete_addr,
 520                                          result,
 521                                          FW_TX_CMPLT_BLOCK_SIZE *
 522                                          sizeof(struct tx_result));
 523                 }
 524
 525         }
 526
 527         wl->next_tx_complete = result_index;
 528 }
 529
 530 /* caller must hold wl->mutex */
 531 void wl1251_tx_flush(struct wl1251 *wl)
 532 {
 533         int i;
 534         struct sk_buff *skb;
 535         struct ieee80211_tx_info *info;
 536
 537         /* TX failure */
 538 /*      control->flags = 0; FIXME */
 539
 540         while ((skb = skb_dequeue(&wl->tx_queue))) {
 541                 info = IEEE80211_SKB_CB(skb);
 542
 543                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 544
 545                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 546                                 continue;
 547
 548                 ieee80211_tx_status(wl->hw, skb);
 549         }
 550
 551         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 552                 if (wl->tx_frames[i] != NULL) {
 553                         skb = wl->tx_frames[i];
 554                         info = IEEE80211_SKB_CB(skb);
 555
 556                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 557                                 continue;
 558
 559                         ieee80211_tx_status(wl->hw, skb);
 560                         wl->tx_frames[i] = NULL;
 561                 }
 562 }