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                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 220                                                                  GFP_KERNEL);
 221
 222                         if (unlikely(newskb == NULL)) {
 223                                 wl1251_error("Can't allocate skb!");
 224                                 return -EINVAL;
 225                         }
 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 /* caller must hold wl->mutex */
 283 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 284 {
 285         struct ieee80211_tx_info *info;
 286         int ret = 0;
 287         u8 idx;
 288
 289         info = IEEE80211_SKB_CB(skb);
 290
 291         if (info->control.hw_key) {
 292                 idx = info->control.hw_key->hw_key_idx;
 293                 if (unlikely(wl->default_key != idx)) {
 294                         ret = wl1251_acx_default_key(wl, idx);
 295                         if (ret < 0)
 296                                 return ret;
 297                 }
 298         }
 299
 300         ret = wl1251_tx_path_status(wl);
 301         if (ret < 0)
 302                 return ret;
 303
 304         ret = wl1251_tx_fill_hdr(wl, skb, info);
 305         if (ret < 0)
 306                 return ret;
 307
 308         ret = wl1251_tx_send_packet(wl, skb, info);
 309         if (ret < 0)
 310                 return ret;
 311
 312         wl1251_tx_trigger(wl);
 313
 314         return ret;
 315 }
 316
 317 void wl1251_tx_work(struct work_struct *work)
 318 {
 319         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 320         struct sk_buff *skb;
 321         bool woken_up = false;
 322         int ret;
 323
 324         mutex_lock(&wl->mutex);
 325
 326         if (unlikely(wl->state == WL1251_STATE_OFF))
 327                 goto out;
 328
 329         while ((skb = skb_dequeue(&wl->tx_queue))) {
 330                 if (!woken_up) {
 331                         ret = wl1251_ps_elp_wakeup(wl);
 332                         if (ret < 0)
 333                                 goto out;
 334                         woken_up = true;
 335                 }
 336
 337                 ret = wl1251_tx_frame(wl, skb);
 338                 if (ret == -EBUSY) {
 339                         skb_queue_head(&wl->tx_queue, skb);
 340                         goto out;
 341                 } else if (ret < 0) {
 342                         dev_kfree_skb(skb);
 343                         goto out;
 344                 }
 345         }
 346
 347 out:
 348         if (woken_up)
 349                 wl1251_ps_elp_sleep(wl);
 350
 351         mutex_unlock(&wl->mutex);
 352 }
 353
 354 static const char *wl1251_tx_parse_status(u8 status)
 355 {
 356         /* 8 bit status field, one character per bit plus null */
 357         static char buf[9];
 358         int i = 0;
 359
 360         memset(buf, 0, sizeof(buf));
 361
 362         if (status & TX_DMA_ERROR)
 363                 buf[i++] = 'm';
 364         if (status & TX_DISABLED)
 365                 buf[i++] = 'd';
 366         if (status & TX_RETRY_EXCEEDED)
 367                 buf[i++] = 'r';
 368         if (status & TX_TIMEOUT)
 369                 buf[i++] = 't';
 370         if (status & TX_KEY_NOT_FOUND)
 371                 buf[i++] = 'k';
 372         if (status & TX_ENCRYPT_FAIL)
 373                 buf[i++] = 'e';
 374         if (status & TX_UNAVAILABLE_PRIORITY)
 375                 buf[i++] = 'p';
 376
 377         /* bit 0 is unused apparently */
 378
 379         return buf;
 380 }
 381
 382 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 383                                 struct tx_result *result)
 384 {
 385         struct ieee80211_tx_info *info;
 386         struct sk_buff *skb;
 387         int hdrlen;
 388         u8 *frame;
 389
 390         skb = wl->tx_frames[result->id];
 391         if (skb == NULL) {
 392                 wl1251_error("SKB for packet %d is NULL", result->id);
 393                 return;
 394         }
 395
 396         info = IEEE80211_SKB_CB(skb);
 397
 398         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 399             (result->status == TX_SUCCESS))
 400                 info->flags |= IEEE80211_TX_STAT_ACK;
 401
 402         info->status.rates[0].count = result->ack_failures + 1;
 403         wl->stats.retry_count += result->ack_failures;
 404
 405         /*
 406          * We have to remove our private TX header before pushing
 407          * the skb back to mac80211.
 408          */
 409         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 410         if (info->control.hw_key &&
 411             info->control.hw_key->alg == ALG_TKIP) {
 412                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 413                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 414                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 415         }
 416
 417         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 418                      " status 0x%x (%s)",
 419                      result->id, skb, result->ack_failures, result->rate,
 420                      result->status, wl1251_tx_parse_status(result->status));
 421
 422
 423         ieee80211_tx_status(wl->hw, skb);
 424
 425         wl->tx_frames[result->id] = NULL;
 426 }
 427
 428 /* Called upon reception of a TX complete interrupt */
 429 void wl1251_tx_complete(struct wl1251 *wl)
 430 {
 431         int i, result_index, num_complete = 0, queue_len;
 432         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 433         unsigned long flags;
 434
 435         if (unlikely(wl->state != WL1251_STATE_ON))
 436                 return;
 437
 438         /* First we read the result */
 439         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 440                             result, sizeof(result));
 441
 442         result_index = wl->next_tx_complete;
 443
 444         for (i = 0; i < ARRAY_SIZE(result); i++) {
 445                 result_ptr = &result[result_index];
 446
 447                 if (result_ptr->done_1 == 1 &&
 448                     result_ptr->done_2 == 1) {
 449                         wl1251_tx_packet_cb(wl, result_ptr);
 450
 451                         result_ptr->done_1 = 0;
 452                         result_ptr->done_2 = 0;
 453
 454                         result_index = (result_index + 1) &
 455                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 456                         num_complete++;
 457                 } else {
 458                         break;
 459                 }
 460         }
 461
 462         queue_len = skb_queue_len(&wl->tx_queue);
 463
 464         if ((num_complete > 0) && (queue_len > 0)) {
 465                 /* firmware buffer has space, reschedule tx_work */
 466                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 467                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 468         }
 469
 470         if (wl->tx_queue_stopped &&
 471             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 472                 /* tx_queue has space, restart queues */
 473                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 474                 spin_lock_irqsave(&wl->wl_lock, flags);
 475                 ieee80211_wake_queues(wl->hw);
 476                 wl->tx_queue_stopped = false;
 477                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 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 }