root/drivers/net/wireless/ti/wl1251/tx.c

DEFINITIONS

1. wl1251_tx_double_buffer_busy
2. wl1251_tx_path_status
3. wl1251_tx_id
4. wl1251_tx_control
5. wl1251_tx_frag_block_num
6. wl1251_tx_fill_hdr
7. wl1251_tx_send_packet
8. wl1251_tx_trigger
9. enable_tx_for_packet_injection
10. wl1251_tx_frame
11. wl1251_tx_work
12. wl1251_tx_parse_status
13. wl1251_tx_packet_cb
14. wl1251_tx_complete
15. wl1251_tx_flush

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * This file is part of wl1251
   4  *
   5  * Copyright (c) 1998-2007 Texas Instruments Incorporated
   6  * Copyright (C) 2008 Nokia Corporation
   7  */
   8 
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 
  12 #include "wl1251.h"
  13 #include "reg.h"
  14 #include "tx.h"
  15 #include "ps.h"
  16 #include "io.h"
  17 #include "event.h"
  18 
  19 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  20 {
  21         int used, data_in_count;
  22 
  23         data_in_count = wl->data_in_count;
  24 
  25         if (data_in_count < data_out_count)
  26                 /* data_in_count has wrapped */
  27                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  28 
  29         used = data_in_count - data_out_count;
  30 
  31         WARN_ON(used < 0);
  32         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  33 
  34         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  35                 return true;
  36         else
  37                 return false;
  38 }
  39 
  40 static int wl1251_tx_path_status(struct wl1251 *wl)
  41 {
  42         u32 status, addr, data_out_count;
  43         bool busy;
  44 
  45         addr = wl->data_path->tx_control_addr;
  46         status = wl1251_mem_read32(wl, addr);
  47         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  48         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  49 
  50         if (busy)
  51                 return -EBUSY;
  52 
  53         return 0;
  54 }
  55 
  56 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  57 {
  58         int i;
  59 
  60         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  61                 if (wl->tx_frames[i] == NULL) {
  62                         wl->tx_frames[i] = skb;
  63                         return i;
  64                 }
  65 
  66         return -EBUSY;
  67 }
  68 
  69 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  70                               struct ieee80211_tx_info *control, u16 fc)
  71 {
  72         *(u16 *)&tx_hdr->control = 0;
  73 
  74         tx_hdr->control.rate_policy = 0;
  75 
  76         /* 802.11 packets */
  77         tx_hdr->control.packet_type = 0;
  78 
  79         /* Also disable retry and ACK policy for injected packets */
  80         if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
  81             (control->flags & IEEE80211_TX_CTL_INJECTED)) {
  82                 tx_hdr->control.rate_policy = 1;
  83                 tx_hdr->control.ack_policy = 1;
  84         }
  85 
  86         tx_hdr->control.tx_complete = 1;
  87 
  88         if ((fc & IEEE80211_FTYPE_DATA) &&
  89             ((fc & IEEE80211_STYPE_QOS_DATA) ||
  90              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
  91                 tx_hdr->control.qos = 1;
  92 }
  93 
  94 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
  95 #define MAX_MSDU_SECURITY_LENGTH      16
  96 #define MAX_MPDU_SECURITY_LENGTH      16
  97 #define WLAN_QOS_HDR_LEN              26
  98 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
  99                                        WLAN_QOS_HDR_LEN)
 100 #define HW_BLOCK_SIZE                 252
 101 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 102 {
 103         u16 payload_len, frag_threshold, mem_blocks;
 104         u16 num_mpdus, mem_blocks_per_frag;
 105 
 106         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 107         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 108 
 109         payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 110 
 111         if (payload_len > frag_threshold) {
 112                 mem_blocks_per_frag =
 113                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 114                          HW_BLOCK_SIZE) + 1;
 115                 num_mpdus = payload_len / frag_threshold;
 116                 mem_blocks = num_mpdus * mem_blocks_per_frag;
 117                 payload_len -= num_mpdus * frag_threshold;
 118                 num_mpdus++;
 119 
 120         } else {
 121                 mem_blocks_per_frag = 0;
 122                 mem_blocks = 0;
 123                 num_mpdus = 1;
 124         }
 125 
 126         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 127 
 128         if (num_mpdus > 1)
 129                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 130 
 131         tx_hdr->num_mem_blocks = mem_blocks;
 132 }
 133 
 134 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 135                               struct ieee80211_tx_info *control)
 136 {
 137         struct tx_double_buffer_desc *tx_hdr;
 138         struct ieee80211_rate *rate;
 139         int id;
 140         u16 fc;
 141 
 142         if (!skb)
 143                 return -EINVAL;
 144 
 145         id = wl1251_tx_id(wl, skb);
 146         if (id < 0)
 147                 return id;
 148 
 149         fc = *(u16 *)skb->data;
 150         tx_hdr = skb_push(skb, sizeof(*tx_hdr));
 151 
 152         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 153         rate = ieee80211_get_tx_rate(wl->hw, control);
 154         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 155         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 156         tx_hdr->id = id;
 157 
 158         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 159 
 160         wl1251_tx_control(tx_hdr, control, fc);
 161         wl1251_tx_frag_block_num(tx_hdr);
 162 
 163         return 0;
 164 }
 165 
 166 /* We copy the packet to the target */
 167 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 168                                  struct ieee80211_tx_info *control)
 169 {
 170         struct tx_double_buffer_desc *tx_hdr;
 171         int len;
 172         u32 addr;
 173 
 174         if (!skb)
 175                 return -EINVAL;
 176 
 177         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 178 
 179         if (control->control.hw_key &&
 180             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 181                 int hdrlen;
 182                 __le16 fc;
 183                 u16 length;
 184                 u8 *pos;
 185 
 186                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 187                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 188                 tx_hdr->length = cpu_to_le16(length);
 189 
 190                 hdrlen = ieee80211_hdrlen(fc);
 191 
 192                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 193                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 194                         sizeof(*tx_hdr) + hdrlen);
 195         }
 196 
 197         /* Revisit. This is a workaround for getting non-aligned packets.
 198            This happens at least with EAPOL packets from the user space.
 199            Our DMA requires packets to be aligned on a 4-byte boundary.
 200         */
 201         if (unlikely((long)skb->data & 0x03)) {
 202                 int offset = (4 - (long)skb->data) & 0x03;
 203                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 204 
 205                 /* check whether the current skb can be used */
 206                 if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 207                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 208                                                                  GFP_KERNEL);
 209 
 210                         if (unlikely(newskb == NULL))
 211                                 return -EINVAL;
 212 
 213                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 214 
 215                         dev_kfree_skb_any(skb);
 216                         wl->tx_frames[tx_hdr->id] = skb = newskb;
 217 
 218                         offset = (4 - (long)skb->data) & 0x03;
 219                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 220                 }
 221 
 222                 /* align the buffer on a 4-byte boundary */
 223                 if (offset) {
 224                         unsigned char *src = skb->data;
 225                         skb_reserve(skb, offset);
 226                         memmove(skb->data, src, skb->len);
 227                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 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 static void enable_tx_for_packet_injection(struct wl1251 *wl)
 269 {
 270         int ret;
 271 
 272         ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
 273                               wl->beacon_int, wl->dtim_period);
 274         if (ret < 0) {
 275                 wl1251_warning("join failed");
 276                 return;
 277         }
 278 
 279         ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
 280         if (ret < 0) {
 281                 wl1251_warning("join timeout");
 282                 return;
 283         }
 284 
 285         wl->joined = true;
 286 }
 287 
 288 /* caller must hold wl->mutex */
 289 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 290 {
 291         struct ieee80211_tx_info *info;
 292         int ret = 0;
 293         u8 idx;
 294 
 295         info = IEEE80211_SKB_CB(skb);
 296 
 297         if (info->control.hw_key) {
 298                 if (unlikely(wl->monitor_present))
 299                         return -EINVAL;
 300 
 301                 idx = info->control.hw_key->hw_key_idx;
 302                 if (unlikely(wl->default_key != idx)) {
 303                         ret = wl1251_acx_default_key(wl, idx);
 304                         if (ret < 0)
 305                                 return ret;
 306                 }
 307         }
 308 
 309         /* Enable tx path in monitor mode for packet injection */
 310         if ((wl->vif == NULL) && !wl->joined)
 311                 enable_tx_for_packet_injection(wl);
 312 
 313         ret = wl1251_tx_path_status(wl);
 314         if (ret < 0)
 315                 return ret;
 316 
 317         ret = wl1251_tx_fill_hdr(wl, skb, info);
 318         if (ret < 0)
 319                 return ret;
 320 
 321         ret = wl1251_tx_send_packet(wl, skb, info);
 322         if (ret < 0)
 323                 return ret;
 324 
 325         wl1251_tx_trigger(wl);
 326 
 327         return ret;
 328 }
 329 
 330 void wl1251_tx_work(struct work_struct *work)
 331 {
 332         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 333         struct sk_buff *skb;
 334         bool woken_up = false;
 335         int ret;
 336 
 337         mutex_lock(&wl->mutex);
 338 
 339         if (unlikely(wl->state == WL1251_STATE_OFF))
 340                 goto out;
 341 
 342         while ((skb = skb_dequeue(&wl->tx_queue))) {
 343                 if (!woken_up) {
 344                         ret = wl1251_ps_elp_wakeup(wl);
 345                         if (ret < 0)
 346                                 goto out;
 347                         woken_up = true;
 348                 }
 349 
 350                 ret = wl1251_tx_frame(wl, skb);
 351                 if (ret == -EBUSY) {
 352                         skb_queue_head(&wl->tx_queue, skb);
 353                         goto out;
 354                 } else if (ret < 0) {
 355                         dev_kfree_skb(skb);
 356                         goto out;
 357                 }
 358         }
 359 
 360 out:
 361         if (woken_up)
 362                 wl1251_ps_elp_sleep(wl);
 363 
 364         mutex_unlock(&wl->mutex);
 365 }
 366 
 367 static const char *wl1251_tx_parse_status(u8 status)
 368 {
 369         /* 8 bit status field, one character per bit plus null */
 370         static char buf[9];
 371         int i = 0;
 372 
 373         memset(buf, 0, sizeof(buf));
 374 
 375         if (status & TX_DMA_ERROR)
 376                 buf[i++] = 'm';
 377         if (status & TX_DISABLED)
 378                 buf[i++] = 'd';
 379         if (status & TX_RETRY_EXCEEDED)
 380                 buf[i++] = 'r';
 381         if (status & TX_TIMEOUT)
 382                 buf[i++] = 't';
 383         if (status & TX_KEY_NOT_FOUND)
 384                 buf[i++] = 'k';
 385         if (status & TX_ENCRYPT_FAIL)
 386                 buf[i++] = 'e';
 387         if (status & TX_UNAVAILABLE_PRIORITY)
 388                 buf[i++] = 'p';
 389 
 390         /* bit 0 is unused apparently */
 391 
 392         return buf;
 393 }
 394 
 395 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 396                                 struct tx_result *result)
 397 {
 398         struct ieee80211_tx_info *info;
 399         struct sk_buff *skb;
 400         int hdrlen;
 401         u8 *frame;
 402 
 403         skb = wl->tx_frames[result->id];
 404         if (skb == NULL) {
 405                 wl1251_error("SKB for packet %d is NULL", result->id);
 406                 return;
 407         }
 408 
 409         info = IEEE80211_SKB_CB(skb);
 410 
 411         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 412             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 413             (result->status == TX_SUCCESS))
 414                 info->flags |= IEEE80211_TX_STAT_ACK;
 415 
 416         info->status.rates[0].count = result->ack_failures + 1;
 417         wl->stats.retry_count += result->ack_failures;
 418 
 419         /*
 420          * We have to remove our private TX header before pushing
 421          * the skb back to mac80211.
 422          */
 423         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 424         if (info->control.hw_key &&
 425             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 426                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 427                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 428                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 429         }
 430 
 431         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 432                      " status 0x%x (%s)",
 433                      result->id, skb, result->ack_failures, result->rate,
 434                      result->status, wl1251_tx_parse_status(result->status));
 435 
 436 
 437         ieee80211_tx_status(wl->hw, skb);
 438 
 439         wl->tx_frames[result->id] = NULL;
 440 }
 441 
 442 /* Called upon reception of a TX complete interrupt */
 443 void wl1251_tx_complete(struct wl1251 *wl)
 444 {
 445         int i, result_index, num_complete = 0, queue_len;
 446         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 447         unsigned long flags;
 448 
 449         if (unlikely(wl->state != WL1251_STATE_ON))
 450                 return;
 451 
 452         /* First we read the result */
 453         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 454                             result, sizeof(result));
 455 
 456         result_index = wl->next_tx_complete;
 457 
 458         for (i = 0; i < ARRAY_SIZE(result); i++) {
 459                 result_ptr = &result[result_index];
 460 
 461                 if (result_ptr->done_1 == 1 &&
 462                     result_ptr->done_2 == 1) {
 463                         wl1251_tx_packet_cb(wl, result_ptr);
 464 
 465                         result_ptr->done_1 = 0;
 466                         result_ptr->done_2 = 0;
 467 
 468                         result_index = (result_index + 1) &
 469                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 470                         num_complete++;
 471                 } else {
 472                         break;
 473                 }
 474         }
 475 
 476         queue_len = skb_queue_len(&wl->tx_queue);
 477 
 478         if ((num_complete > 0) && (queue_len > 0)) {
 479                 /* firmware buffer has space, reschedule tx_work */
 480                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 481                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 482         }
 483 
 484         if (wl->tx_queue_stopped &&
 485             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 486                 /* tx_queue has space, restart queues */
 487                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 488                 spin_lock_irqsave(&wl->wl_lock, flags);
 489                 ieee80211_wake_queues(wl->hw);
 490                 wl->tx_queue_stopped = false;
 491                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 492         }
 493 
 494         /* Every completed frame needs to be acknowledged */
 495         if (num_complete) {
 496                 /*
 497                  * If we've wrapped, we have to clear
 498                  * the results in 2 steps.
 499                  */
 500                 if (result_index > wl->next_tx_complete) {
 501                         /* Only 1 write is needed */
 502                         wl1251_mem_write(wl,
 503                                          wl->data_path->tx_complete_addr +
 504                                          (wl->next_tx_complete *
 505                                           sizeof(struct tx_result)),
 506                                          &result[wl->next_tx_complete],
 507                                          num_complete *
 508                                          sizeof(struct tx_result));
 509 
 510 
 511                 } else if (result_index < wl->next_tx_complete) {
 512                         /* 2 writes are needed */
 513                         wl1251_mem_write(wl,
 514                                          wl->data_path->tx_complete_addr +
 515                                          (wl->next_tx_complete *
 516                                           sizeof(struct tx_result)),
 517                                          &result[wl->next_tx_complete],
 518                                          (FW_TX_CMPLT_BLOCK_SIZE -
 519                                           wl->next_tx_complete) *
 520                                          sizeof(struct tx_result));
 521 
 522                         wl1251_mem_write(wl,
 523                                          wl->data_path->tx_complete_addr,
 524                                          result,
 525                                          (num_complete -
 526                                           FW_TX_CMPLT_BLOCK_SIZE +
 527                                           wl->next_tx_complete) *
 528                                          sizeof(struct tx_result));
 529 
 530                 } else {
 531                         /* We have to write the whole array */
 532                         wl1251_mem_write(wl,
 533                                          wl->data_path->tx_complete_addr,
 534                                          result,
 535                                          FW_TX_CMPLT_BLOCK_SIZE *
 536                                          sizeof(struct tx_result));
 537                 }
 538 
 539         }
 540 
 541         wl->next_tx_complete = result_index;
 542 }
 543 
 544 /* caller must hold wl->mutex */
 545 void wl1251_tx_flush(struct wl1251 *wl)
 546 {
 547         int i;
 548         struct sk_buff *skb;
 549         struct ieee80211_tx_info *info;
 550 
 551         /* TX failure */
 552 /*      control->flags = 0; FIXME */
 553 
 554         while ((skb = skb_dequeue(&wl->tx_queue))) {
 555                 info = IEEE80211_SKB_CB(skb);
 556 
 557                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 558 
 559                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 560                                 continue;
 561 
 562                 ieee80211_tx_status(wl->hw, skb);
 563         }
 564 
 565         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 566                 if (wl->tx_frames[i] != NULL) {
 567                         skb = wl->tx_frames[i];
 568                         info = IEEE80211_SKB_CB(skb);
 569 
 570                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 571                                 continue;
 572 
 573                         ieee80211_tx_status(wl->hw, skb);
 574                         wl->tx_frames[i] = NULL;
 575                 }
 576 }