drivers/net/wireless/wl12xx/tx.c

   1 /*
   2  * This file is part of wl12xx
   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 "wl12xx.h"
  29 #include "reg.h"
  30 #include "spi.h"
  31 #include "tx.h"
  32 #include "ps.h"
  33
  34 static bool wl12xx_tx_double_buffer_busy(struct wl12xx *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 wl12xx_tx_path_status(struct wl12xx *wl)
  56 {
  57         u32 status, addr, data_out_count;
  58         bool busy;
  59
  60         addr = wl->data_path->tx_control_addr;
  61         status = wl12xx_mem_read32(wl, addr);
  62         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  63         busy = wl12xx_tx_double_buffer_busy(wl, data_out_count);
  64
  65         if (busy)
  66                 return -EBUSY;
  67
  68         return 0;
  69 }
  70
  71 static int wl12xx_tx_id(struct wl12xx *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 wl12xx_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 wl12xx_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 wl12xx_tx_fill_hdr(struct wl12xx *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 = wl12xx_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         /* FIXME: how to get the correct queue id? */
 171         tx_hdr->xmit_queue = 0;
 172
 173         wl12xx_tx_control(tx_hdr, control, fc);
 174         wl12xx_tx_frag_block_num(tx_hdr);
 175
 176         return 0;
 177 }
 178
 179 /* We copy the packet to the target */
 180 static int wl12xx_tx_send_packet(struct wl12xx *wl, struct sk_buff *skb,
 181                                  struct ieee80211_tx_info *control)
 182 {
 183         struct tx_double_buffer_desc *tx_hdr;
 184         int len;
 185         u32 addr;
 186
 187         if (!skb)
 188                 return -EINVAL;
 189
 190         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 191
 192         if (control->control.hw_key &&
 193             control->control.hw_key->alg == ALG_TKIP) {
 194                 int hdrlen;
 195                 u16 fc;
 196                 u8 *pos;
 197
 198                 fc = *(u16 *)(skb->data + sizeof(*tx_hdr));
 199                 tx_hdr->length += WL12XX_TKIP_IV_SPACE;
 200
 201                 hdrlen = ieee80211_hdrlen(fc);
 202
 203                 pos = skb_push(skb, WL12XX_TKIP_IV_SPACE);
 204                 memmove(pos, pos + WL12XX_TKIP_IV_SPACE,
 205                         sizeof(*tx_hdr) + hdrlen);
 206         }
 207
 208         /* Revisit. This is a workaround for getting non-aligned packets.
 209            This happens at least with EAPOL packets from the user space.
 210            Our DMA requires packets to be aligned on a 4-byte boundary.
 211         */
 212         if (unlikely((long)skb->data & 0x03)) {
 213                 int offset = (4 - (long)skb->data) & 0x03;
 214                 wl12xx_debug(DEBUG_TX, "skb offset %d", offset);
 215
 216                 /* check whether the current skb can be used */
 217                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 218                         unsigned char *src = skb->data;
 219
 220                         /* align the buffer on a 4-byte boundary */
 221                         skb_reserve(skb, offset);
 222                         memmove(skb->data, src, skb->len);
 223                 } else {
 224                         wl12xx_info("No handler, fixme!");
 225                         return -EINVAL;
 226                 }
 227         }
 228
 229         /* Our skb->data at this point includes the HW header */
 230         len = WL12XX_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         wl12xx_spi_mem_write(wl, addr, skb->data, len);
 239
 240         wl12xx_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x",
 241                      tx_hdr->id, skb, tx_hdr->length, tx_hdr->rate);
 242
 243         return 0;
 244 }
 245
 246 static void wl12xx_tx_trigger(struct wl12xx *wl)
 247 {
 248         u32 data, addr;
 249
 250         if (wl->data_in_count & 0x1) {
 251                 addr = ACX_REG_INTERRUPT_TRIG_H;
 252                 data = INTR_TRIG_TX_PROC1;
 253         } else {
 254                 addr = ACX_REG_INTERRUPT_TRIG;
 255                 data = INTR_TRIG_TX_PROC0;
 256         }
 257
 258         wl12xx_reg_write32(wl, addr, data);
 259
 260         /* Bumping data in */
 261         wl->data_in_count = (wl->data_in_count + 1) &
 262                 TX_STATUS_DATA_OUT_COUNT_MASK;
 263 }
 264
 265 /* caller must hold wl->mutex */
 266 static int wl12xx_tx_frame(struct wl12xx *wl, struct sk_buff *skb)
 267 {
 268         struct ieee80211_tx_info *info;
 269         int ret = 0;
 270         u8 idx;
 271
 272         info = IEEE80211_SKB_CB(skb);
 273
 274         if (info->control.hw_key) {
 275                 idx = info->control.hw_key->hw_key_idx;
 276                 if (unlikely(wl->default_key != idx)) {
 277                         ret = wl12xx_acx_default_key(wl, idx);
 278                         if (ret < 0)
 279                                 return ret;
 280                 }
 281         }
 282
 283         ret = wl12xx_tx_path_status(wl);
 284         if (ret < 0)
 285                 return ret;
 286
 287         ret = wl12xx_tx_fill_hdr(wl, skb, info);
 288         if (ret < 0)
 289                 return ret;
 290
 291         ret = wl12xx_tx_send_packet(wl, skb, info);
 292         if (ret < 0)
 293                 return ret;
 294
 295         wl12xx_tx_trigger(wl);
 296
 297         return ret;
 298 }
 299
 300 void wl12xx_tx_work(struct work_struct *work)
 301 {
 302         struct wl12xx *wl = container_of(work, struct wl12xx, tx_work);
 303         struct sk_buff *skb;
 304         bool woken_up = false;
 305         int ret;
 306
 307         mutex_lock(&wl->mutex);
 308
 309         if (unlikely(wl->state == WL12XX_STATE_OFF))
 310                 goto out;
 311
 312         while ((skb = skb_dequeue(&wl->tx_queue))) {
 313                 if (!woken_up) {
 314                         wl12xx_ps_elp_wakeup(wl);
 315                         woken_up = true;
 316                 }
 317
 318                 ret = wl12xx_tx_frame(wl, skb);
 319                 if (ret == -EBUSY) {
 320                         /* firmware buffer is full, stop queues */
 321                         wl12xx_debug(DEBUG_TX, "tx_work: fw buffer full, "
 322                                      "stop queues");
 323                         ieee80211_stop_queues(wl->hw);
 324                         wl->tx_queue_stopped = true;
 325                         skb_queue_head(&wl->tx_queue, skb);
 326                         goto out;
 327                 } else if (ret < 0) {
 328                         dev_kfree_skb(skb);
 329                         goto out;
 330                 }
 331         }
 332
 333 out:
 334         if (woken_up)
 335                 wl12xx_ps_elp_sleep(wl);
 336
 337         mutex_unlock(&wl->mutex);
 338 }
 339
 340 static const char *wl12xx_tx_parse_status(u8 status)
 341 {
 342         /* 8 bit status field, one character per bit plus null */
 343         static char buf[9];
 344         int i = 0;
 345
 346         memset(buf, 0, sizeof(buf));
 347
 348         if (status & TX_DMA_ERROR)
 349                 buf[i++] = 'm';
 350         if (status & TX_DISABLED)
 351                 buf[i++] = 'd';
 352         if (status & TX_RETRY_EXCEEDED)
 353                 buf[i++] = 'r';
 354         if (status & TX_TIMEOUT)
 355                 buf[i++] = 't';
 356         if (status & TX_KEY_NOT_FOUND)
 357                 buf[i++] = 'k';
 358         if (status & TX_ENCRYPT_FAIL)
 359                 buf[i++] = 'e';
 360         if (status & TX_UNAVAILABLE_PRIORITY)
 361                 buf[i++] = 'p';
 362
 363         /* bit 0 is unused apparently */
 364
 365         return buf;
 366 }
 367
 368 static void wl12xx_tx_packet_cb(struct wl12xx *wl,
 369                                 struct tx_result *result)
 370 {
 371         struct ieee80211_tx_info *info;
 372         struct sk_buff *skb;
 373         int hdrlen, ret;
 374         u8 *frame;
 375
 376         skb = wl->tx_frames[result->id];
 377         if (skb == NULL) {
 378                 wl12xx_error("SKB for packet %d is NULL", result->id);
 379                 return;
 380         }
 381
 382         info = IEEE80211_SKB_CB(skb);
 383
 384         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 385             (result->status == TX_SUCCESS))
 386                 info->flags |= IEEE80211_TX_STAT_ACK;
 387
 388         info->status.rates[0].count = result->ack_failures + 1;
 389         wl->stats.retry_count += result->ack_failures;
 390
 391         /*
 392          * We have to remove our private TX header before pushing
 393          * the skb back to mac80211.
 394          */
 395         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 396         if (info->control.hw_key &&
 397             info->control.hw_key->alg == ALG_TKIP) {
 398                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 399                 memmove(frame + WL12XX_TKIP_IV_SPACE, frame, hdrlen);
 400                 skb_pull(skb, WL12XX_TKIP_IV_SPACE);
 401         }
 402
 403         wl12xx_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 404                      " status 0x%x (%s)",
 405                      result->id, skb, result->ack_failures, result->rate,
 406                      result->status, wl12xx_tx_parse_status(result->status));
 407
 408
 409         ieee80211_tx_status(wl->hw, skb);
 410
 411         wl->tx_frames[result->id] = NULL;
 412
 413         if (wl->tx_queue_stopped) {
 414                 wl12xx_debug(DEBUG_TX, "cb: queue was stopped");
 415
 416                 skb = skb_dequeue(&wl->tx_queue);
 417
 418                 /* The skb can be NULL because tx_work might have been
 419                    scheduled before the queue was stopped making the
 420                    queue empty */
 421
 422                 if (skb) {
 423                         ret = wl12xx_tx_frame(wl, skb);
 424                         if (ret == -EBUSY) {
 425                                 /* firmware buffer is still full */
 426                                 wl12xx_debug(DEBUG_TX, "cb: fw buffer "
 427                                              "still full");
 428                                 skb_queue_head(&wl->tx_queue, skb);
 429                                 return;
 430                         } else if (ret < 0) {
 431                                 dev_kfree_skb(skb);
 432                                 return;
 433                         }
 434                 }
 435
 436                 wl12xx_debug(DEBUG_TX, "cb: waking queues");
 437                 ieee80211_wake_queues(wl->hw);
 438                 wl->tx_queue_stopped = false;
 439         }
 440 }
 441
 442 /* Called upon reception of a TX complete interrupt */
 443 void wl12xx_tx_complete(struct wl12xx *wl)
 444 {
 445         int i, result_index, num_complete = 0;
 446         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 447
 448         if (unlikely(wl->state != WL12XX_STATE_ON))
 449                 return;
 450
 451         /* First we read the result */
 452         wl12xx_spi_mem_read(wl, wl->data_path->tx_complete_addr,
 453                             result, sizeof(result));
 454
 455         result_index = wl->next_tx_complete;
 456
 457         for (i = 0; i < ARRAY_SIZE(result); i++) {
 458                 result_ptr = &result[result_index];
 459
 460                 if (result_ptr->done_1 == 1 &&
 461                     result_ptr->done_2 == 1) {
 462                         wl12xx_tx_packet_cb(wl, result_ptr);
 463
 464                         result_ptr->done_1 = 0;
 465                         result_ptr->done_2 = 0;
 466
 467                         result_index = (result_index + 1) &
 468                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 469                         num_complete++;
 470                 } else {
 471                         break;
 472                 }
 473         }
 474
 475         /* Every completed frame needs to be acknowledged */
 476         if (num_complete) {
 477                 /*
 478                  * If we've wrapped, we have to clear
 479                  * the results in 2 steps.
 480                  */
 481                 if (result_index > wl->next_tx_complete) {
 482                         /* Only 1 write is needed */
 483                         wl12xx_spi_mem_write(wl,
 484                                              wl->data_path->tx_complete_addr +
 485                                              (wl->next_tx_complete *
 486                                               sizeof(struct tx_result)),
 487                                              &result[wl->next_tx_complete],
 488                                              num_complete *
 489                                              sizeof(struct tx_result));
 490
 491
 492                 } else if (result_index < wl->next_tx_complete) {
 493                         /* 2 writes are needed */
 494                         wl12xx_spi_mem_write(wl,
 495                                              wl->data_path->tx_complete_addr +
 496                                              (wl->next_tx_complete *
 497                                               sizeof(struct tx_result)),
 498                                              &result[wl->next_tx_complete],
 499                                              (FW_TX_CMPLT_BLOCK_SIZE -
 500                                               wl->next_tx_complete) *
 501                                              sizeof(struct tx_result));
 502
 503                         wl12xx_spi_mem_write(wl,
 504                                              wl->data_path->tx_complete_addr,
 505                                              result,
 506                                              (num_complete -
 507                                               FW_TX_CMPLT_BLOCK_SIZE +
 508                                               wl->next_tx_complete) *
 509                                              sizeof(struct tx_result));
 510
 511                 } else {
 512                         /* We have to write the whole array */
 513                         wl12xx_spi_mem_write(wl,
 514                                              wl->data_path->tx_complete_addr,
 515                                              result,
 516                                              FW_TX_CMPLT_BLOCK_SIZE *
 517                                              sizeof(struct tx_result));
 518                 }
 519
 520         }
 521
 522         wl->next_tx_complete = result_index;
 523 }
 524
 525 /* caller must hold wl->mutex */
 526 void wl12xx_tx_flush(struct wl12xx *wl)
 527 {
 528         int i;
 529         struct sk_buff *skb;
 530         struct ieee80211_tx_info *info;
 531
 532         /* TX failure */
 533 /*      control->flags = 0; FIXME */
 534
 535         while ((skb = skb_dequeue(&wl->tx_queue))) {
 536                 info = IEEE80211_SKB_CB(skb);
 537
 538                 wl12xx_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 539
 540                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 541                                 continue;
 542
 543                 ieee80211_tx_status(wl->hw, skb);
 544         }
 545
 546         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 547                 if (wl->tx_frames[i] != NULL) {
 548                         skb = wl->tx_frames[i];
 549                         info = IEEE80211_SKB_CB(skb);
 550
 551                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 552                                 continue;
 553
 554                         ieee80211_tx_status(wl->hw, skb);
 555                         wl->tx_frames[i] = NULL;
 556                 }
 557 }