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
  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                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 218                                                                  GFP_KERNEL);
 219
 220                         if (unlikely(newskb == NULL)) {
 221                                 wl1251_error("Can't allocate skb!");
 222                                 return -EINVAL;
 223                         }
 224
 225                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 226
 227                         dev_kfree_skb_any(skb);
 228                         wl->tx_frames[tx_hdr->id] = skb = newskb;
 229
 230                         offset = (4 - (long)skb->data) & 0x03;
 231                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 232                 }
 233
 234                 /* align the buffer on a 4-byte boundary */
 235                 if (offset) {
 236                         unsigned char *src = skb->data;
 237                         skb_reserve(skb, offset);
 238                         memmove(skb->data, src, skb->len);
 239                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 240                 }
 241         }
 242
 243         /* Our skb->data at this point includes the HW header */
 244         len = WL1251_TX_ALIGN(skb->len);
 245
 246         if (wl->data_in_count & 0x1)
 247                 addr = wl->data_path->tx_packet_ring_addr +
 248                         wl->data_path->tx_packet_ring_chunk_size;
 249         else
 250                 addr = wl->data_path->tx_packet_ring_addr;
 251
 252         wl1251_mem_write(wl, addr, skb->data, len);
 253
 254         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 255                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 256                      tx_hdr->rate, tx_hdr->xmit_queue);
 257
 258         return 0;
 259 }
 260
 261 static void wl1251_tx_trigger(struct wl1251 *wl)
 262 {
 263         u32 data, addr;
 264
 265         if (wl->data_in_count & 0x1) {
 266                 addr = ACX_REG_INTERRUPT_TRIG_H;
 267                 data = INTR_TRIG_TX_PROC1;
 268         } else {
 269                 addr = ACX_REG_INTERRUPT_TRIG;
 270                 data = INTR_TRIG_TX_PROC0;
 271         }
 272
 273         wl1251_reg_write32(wl, addr, data);
 274
 275         /* Bumping data in */
 276         wl->data_in_count = (wl->data_in_count + 1) &
 277                 TX_STATUS_DATA_OUT_COUNT_MASK;
 278 }
 279
 280 /* caller must hold wl->mutex */
 281 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 282 {
 283         struct ieee80211_tx_info *info;
 284         int ret = 0;
 285         u8 idx;
 286
 287         info = IEEE80211_SKB_CB(skb);
 288
 289         if (info->control.hw_key) {
 290                 idx = info->control.hw_key->hw_key_idx;
 291                 if (unlikely(wl->default_key != idx)) {
 292                         ret = wl1251_acx_default_key(wl, idx);
 293                         if (ret < 0)
 294                                 return ret;
 295                 }
 296         }
 297
 298         ret = wl1251_tx_path_status(wl);
 299         if (ret < 0)
 300                 return ret;
 301
 302         ret = wl1251_tx_fill_hdr(wl, skb, info);
 303         if (ret < 0)
 304                 return ret;
 305
 306         ret = wl1251_tx_send_packet(wl, skb, info);
 307         if (ret < 0)
 308                 return ret;
 309
 310         wl1251_tx_trigger(wl);
 311
 312         return ret;
 313 }
 314
 315 void wl1251_tx_work(struct work_struct *work)
 316 {
 317         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 318         struct sk_buff *skb;
 319         bool woken_up = false;
 320         int ret;
 321
 322         mutex_lock(&wl->mutex);
 323
 324         if (unlikely(wl->state == WL1251_STATE_OFF))
 325                 goto out;
 326
 327         while ((skb = skb_dequeue(&wl->tx_queue))) {
 328                 if (!woken_up) {
 329                         ret = wl1251_ps_elp_wakeup(wl);
 330                         if (ret < 0)
 331                                 goto out;
 332                         woken_up = true;
 333                 }
 334
 335                 ret = wl1251_tx_frame(wl, skb);
 336                 if (ret == -EBUSY) {
 337                         skb_queue_head(&wl->tx_queue, skb);
 338                         goto out;
 339                 } else if (ret < 0) {
 340                         dev_kfree_skb(skb);
 341                         goto out;
 342                 }
 343         }
 344
 345 out:
 346         if (woken_up)
 347                 wl1251_ps_elp_sleep(wl);
 348
 349         mutex_unlock(&wl->mutex);
 350 }
 351
 352 static const char *wl1251_tx_parse_status(u8 status)
 353 {
 354         /* 8 bit status field, one character per bit plus null */
 355         static char buf[9];
 356         int i = 0;
 357
 358         memset(buf, 0, sizeof(buf));
 359
 360         if (status & TX_DMA_ERROR)
 361                 buf[i++] = 'm';
 362         if (status & TX_DISABLED)
 363                 buf[i++] = 'd';
 364         if (status & TX_RETRY_EXCEEDED)
 365                 buf[i++] = 'r';
 366         if (status & TX_TIMEOUT)
 367                 buf[i++] = 't';
 368         if (status & TX_KEY_NOT_FOUND)
 369                 buf[i++] = 'k';
 370         if (status & TX_ENCRYPT_FAIL)
 371                 buf[i++] = 'e';
 372         if (status & TX_UNAVAILABLE_PRIORITY)
 373                 buf[i++] = 'p';
 374
 375         /* bit 0 is unused apparently */
 376
 377         return buf;
 378 }
 379
 380 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 381                                 struct tx_result *result)
 382 {
 383         struct ieee80211_tx_info *info;
 384         struct sk_buff *skb;
 385         int hdrlen;
 386         u8 *frame;
 387
 388         skb = wl->tx_frames[result->id];
 389         if (skb == NULL) {
 390                 wl1251_error("SKB for packet %d is NULL", result->id);
 391                 return;
 392         }
 393
 394         info = IEEE80211_SKB_CB(skb);
 395
 396         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 397             (result->status == TX_SUCCESS))
 398                 info->flags |= IEEE80211_TX_STAT_ACK;
 399
 400         info->status.rates[0].count = result->ack_failures + 1;
 401         wl->stats.retry_count += result->ack_failures;
 402
 403         /*
 404          * We have to remove our private TX header before pushing
 405          * the skb back to mac80211.
 406          */
 407         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 408         if (info->control.hw_key &&
 409             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 410                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 411                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 412                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 413         }
 414
 415         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 416                      " status 0x%x (%s)",
 417                      result->id, skb, result->ack_failures, result->rate,
 418                      result->status, wl1251_tx_parse_status(result->status));
 419
 420
 421         ieee80211_tx_status(wl->hw, skb);
 422
 423         wl->tx_frames[result->id] = NULL;
 424 }
 425
 426 /* Called upon reception of a TX complete interrupt */
 427 void wl1251_tx_complete(struct wl1251 *wl)
 428 {
 429         int i, result_index, num_complete = 0, queue_len;
 430         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 431         unsigned long flags;
 432
 433         if (unlikely(wl->state != WL1251_STATE_ON))
 434                 return;
 435
 436         /* First we read the result */
 437         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 438                             result, sizeof(result));
 439
 440         result_index = wl->next_tx_complete;
 441
 442         for (i = 0; i < ARRAY_SIZE(result); i++) {
 443                 result_ptr = &result[result_index];
 444
 445                 if (result_ptr->done_1 == 1 &&
 446                     result_ptr->done_2 == 1) {
 447                         wl1251_tx_packet_cb(wl, result_ptr);
 448
 449                         result_ptr->done_1 = 0;
 450                         result_ptr->done_2 = 0;
 451
 452                         result_index = (result_index + 1) &
 453                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 454                         num_complete++;
 455                 } else {
 456                         break;
 457                 }
 458         }
 459
 460         queue_len = skb_queue_len(&wl->tx_queue);
 461
 462         if ((num_complete > 0) && (queue_len > 0)) {
 463                 /* firmware buffer has space, reschedule tx_work */
 464                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 465                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 466         }
 467
 468         if (wl->tx_queue_stopped &&
 469             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 470                 /* tx_queue has space, restart queues */
 471                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 472                 spin_lock_irqsave(&wl->wl_lock, flags);
 473                 ieee80211_wake_queues(wl->hw);
 474                 wl->tx_queue_stopped = false;
 475                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 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 }