drivers/net/wireless/wl12xx/tx.c

   1 /*
   2  * This file is part of wl1271
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  *
   6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/etherdevice.h>
  27
  28 #include "wl12xx.h"
  29 #include "io.h"
  30 #include "reg.h"
  31 #include "ps.h"
  32 #include "tx.h"
  33
  34 static int wl1271_set_default_wep_key(struct wl1271 *wl, u8 id)
  35 {
  36         int ret;
  37         bool is_ap = (wl->bss_type == BSS_TYPE_AP_BSS);
  38
  39         if (is_ap)
  40                 ret = wl1271_cmd_set_ap_default_wep_key(wl, id);
  41         else
  42                 ret = wl1271_cmd_set_sta_default_wep_key(wl, id);
  43
  44         if (ret < 0)
  45                 return ret;
  46
  47         wl1271_debug(DEBUG_CRYPT, "default wep key idx: %d", (int)id);
  48         return 0;
  49 }
  50
  51 static int wl1271_alloc_tx_id(struct wl1271 *wl, struct sk_buff *skb)
  52 {
  53         int id;
  54
  55         id = find_first_zero_bit(wl->tx_frames_map, ACX_TX_DESCRIPTORS);
  56         if (id >= ACX_TX_DESCRIPTORS)
  57                 return -EBUSY;
  58
  59         __set_bit(id, wl->tx_frames_map);
  60         wl->tx_frames[id] = skb;
  61         wl->tx_frames_cnt++;
  62         return id;
  63 }
  64
  65 static void wl1271_free_tx_id(struct wl1271 *wl, int id)
  66 {
  67         if (__test_and_clear_bit(id, wl->tx_frames_map)) {
  68                 wl->tx_frames[id] = NULL;
  69                 wl->tx_frames_cnt--;
  70         }
  71 }
  72
  73 static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra,
  74                                 u32 buf_offset)
  75 {
  76         struct wl1271_tx_hw_descr *desc;
  77         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
  78         u32 total_blocks;
  79         int id, ret = -EBUSY;
  80
  81         if (buf_offset + total_len > WL1271_AGGR_BUFFER_SIZE)
  82                 return -EAGAIN;
  83
  84         /* allocate free identifier for the packet */
  85         id = wl1271_alloc_tx_id(wl, skb);
  86         if (id < 0)
  87                 return id;
  88
  89         /* approximate the number of blocks required for this packet
  90            in the firmware */
  91         total_blocks = total_len + TX_HW_BLOCK_SIZE - 1;
  92         total_blocks = total_blocks / TX_HW_BLOCK_SIZE + TX_HW_BLOCK_SPARE;
  93         if (total_blocks <= wl->tx_blocks_available) {
  94                 desc = (struct wl1271_tx_hw_descr *)skb_push(
  95                         skb, total_len - skb->len);
  96
  97                 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
  98                 desc->total_mem_blocks = total_blocks;
  99                 desc->id = id;
 100
 101                 wl->tx_blocks_available -= total_blocks;
 102
 103                 ret = 0;
 104
 105                 wl1271_debug(DEBUG_TX,
 106                              "tx_allocate: size: %d, blocks: %d, id: %d",
 107                              total_len, total_blocks, id);
 108         } else {
 109                 wl1271_free_tx_id(wl, id);
 110         }
 111
 112         return ret;
 113 }
 114
 115 static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
 116                               u32 extra, struct ieee80211_tx_info *control)
 117 {
 118         struct timespec ts;
 119         struct wl1271_tx_hw_descr *desc;
 120         int pad, ac, rate_idx;
 121         s64 hosttime;
 122         u16 tx_attr;
 123
 124         desc = (struct wl1271_tx_hw_descr *) skb->data;
 125
 126         /* relocate space for security header */
 127         if (extra) {
 128                 void *framestart = skb->data + sizeof(*desc);
 129                 u16 fc = *(u16 *)(framestart + extra);
 130                 int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
 131                 memmove(framestart, framestart + extra, hdrlen);
 132         }
 133
 134         /* configure packet life time */
 135         getnstimeofday(&ts);
 136         hosttime = (timespec_to_ns(&ts) >> 10);
 137         desc->start_time = cpu_to_le32(hosttime - wl->time_offset);
 138
 139         if (wl->bss_type != BSS_TYPE_AP_BSS)
 140                 desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
 141         else
 142                 desc->life_time = cpu_to_le16(TX_HW_AP_MODE_PKT_LIFETIME_TU);
 143
 144         /* configure the tx attributes */
 145         tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 146
 147         /* queue (we use same identifiers for tid's and ac's */
 148         ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
 149         desc->tid = ac;
 150
 151         if (wl->bss_type != BSS_TYPE_AP_BSS) {
 152                 desc->aid = TX_HW_DEFAULT_AID;
 153
 154                 /* if the packets are destined for AP (have a STA entry)
 155                    send them with AP rate policies, otherwise use default
 156                    basic rates */
 157                 if (control->control.sta)
 158                         rate_idx = ACX_TX_AP_FULL_RATE;
 159                 else
 160                         rate_idx = ACX_TX_BASIC_RATE;
 161         } else {
 162                 if (control->control.sta) {
 163                         struct wl1271_station *wl_sta;
 164
 165                         wl_sta = (struct wl1271_station *)
 166                                         control->control.sta->drv_priv;
 167                         desc->hlid = wl_sta->hlid;
 168                         rate_idx = ac;
 169                 } else {
 170                         struct ieee80211_hdr *hdr;
 171
 172                         hdr = (struct ieee80211_hdr *)
 173                                                 (skb->data + sizeof(*desc));
 174                         if (ieee80211_is_mgmt(hdr->frame_control)) {
 175                                 desc->hlid = WL1271_AP_GLOBAL_HLID;
 176                                 rate_idx = ACX_TX_AP_MODE_MGMT_RATE;
 177                         } else {
 178                                 desc->hlid = WL1271_AP_BROADCAST_HLID;
 179                                 rate_idx = ACX_TX_AP_MODE_BCST_RATE;
 180                         }
 181                 }
 182         }
 183
 184         tx_attr |= rate_idx << TX_HW_ATTR_OFST_RATE_POLICY;
 185         desc->reserved = 0;
 186
 187         /* align the length (and store in terms of words) */
 188         pad = WL1271_TX_ALIGN(skb->len);
 189         desc->length = cpu_to_le16(pad >> 2);
 190
 191         /* calculate number of padding bytes */
 192         pad = pad - skb->len;
 193         tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 194
 195         desc->tx_attr = cpu_to_le16(tx_attr);
 196
 197         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d hlid: %d "
 198                 "tx_attr: 0x%x len: %d life: %d mem: %d", pad, desc->hlid,
 199                 le16_to_cpu(desc->tx_attr), le16_to_cpu(desc->length),
 200                 le16_to_cpu(desc->life_time), desc->total_mem_blocks);
 201 }
 202
 203 /* caller must hold wl->mutex */
 204 static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb,
 205                                                         u32 buf_offset)
 206 {
 207         struct ieee80211_tx_info *info;
 208         u32 extra = 0;
 209         int ret = 0;
 210         u32 total_len;
 211
 212         if (!skb)
 213                 return -EINVAL;
 214
 215         info = IEEE80211_SKB_CB(skb);
 216
 217         if (info->control.hw_key &&
 218             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP)
 219                 extra = WL1271_TKIP_IV_SPACE;
 220
 221         if (info->control.hw_key) {
 222                 bool is_wep;
 223                 u8 idx = info->control.hw_key->hw_key_idx;
 224                 u32 cipher = info->control.hw_key->cipher;
 225
 226                 is_wep = (cipher == WLAN_CIPHER_SUITE_WEP40) ||
 227                          (cipher == WLAN_CIPHER_SUITE_WEP104);
 228
 229                 if (unlikely(is_wep && wl->default_key != idx)) {
 230                         ret = wl1271_set_default_wep_key(wl, idx);
 231                         if (ret < 0)
 232                                 return ret;
 233                         wl->default_key = idx;
 234                 }
 235         }
 236
 237         ret = wl1271_tx_allocate(wl, skb, extra, buf_offset);
 238         if (ret < 0)
 239                 return ret;
 240
 241         wl1271_tx_fill_hdr(wl, skb, extra, info);
 242
 243         /*
 244          * The length of each packet is stored in terms of words. Thus, we must
 245          * pad the skb data to make sure its length is aligned.
 246          * The number of padding bytes is computed and set in wl1271_tx_fill_hdr
 247          */
 248         total_len = WL1271_TX_ALIGN(skb->len);
 249         memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len);
 250         memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len);
 251
 252         return total_len;
 253 }
 254
 255 u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
 256 {
 257         struct ieee80211_supported_band *band;
 258         u32 enabled_rates = 0;
 259         int bit;
 260
 261         band = wl->hw->wiphy->bands[wl->band];
 262         for (bit = 0; bit < band->n_bitrates; bit++) {
 263                 if (rate_set & 0x1)
 264                         enabled_rates |= band->bitrates[bit].hw_value;
 265                 rate_set >>= 1;
 266         }
 267
 268 #ifdef CONFIG_WL12XX_HT
 269         /* MCS rates indication are on bits 16 - 23 */
 270         rate_set >>= HW_HT_RATES_OFFSET - band->n_bitrates;
 271
 272         for (bit = 0; bit < 8; bit++) {
 273                 if (rate_set & 0x1)
 274                         enabled_rates |= (CONF_HW_BIT_RATE_MCS_0 << bit);
 275                 rate_set >>= 1;
 276         }
 277 #endif
 278
 279         return enabled_rates;
 280 }
 281
 282 static void handle_tx_low_watermark(struct wl1271 *wl)
 283 {
 284         unsigned long flags;
 285
 286         if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) &&
 287             wl->tx_queue_count <= WL1271_TX_QUEUE_LOW_WATERMARK) {
 288                 /* firmware buffer has space, restart queues */
 289                 spin_lock_irqsave(&wl->wl_lock, flags);
 290                 ieee80211_wake_queues(wl->hw);
 291                 clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
 292                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 293         }
 294 }
 295
 296 static struct sk_buff *wl1271_skb_dequeue(struct wl1271 *wl)
 297 {
 298         struct sk_buff *skb = NULL;
 299         unsigned long flags;
 300
 301         skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_VO]);
 302         if (skb)
 303                 goto out;
 304         skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_VI]);
 305         if (skb)
 306                 goto out;
 307         skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_BE]);
 308         if (skb)
 309                 goto out;
 310         skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_BK]);
 311
 312 out:
 313         if (skb) {
 314                 spin_lock_irqsave(&wl->wl_lock, flags);
 315                 wl->tx_queue_count--;
 316                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 317         }
 318
 319         return skb;
 320 }
 321
 322 static void wl1271_skb_queue_head(struct wl1271 *wl, struct sk_buff *skb)
 323 {
 324         unsigned long flags;
 325         int q = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
 326
 327         skb_queue_head(&wl->tx_queue[q], skb);
 328         spin_lock_irqsave(&wl->wl_lock, flags);
 329         wl->tx_queue_count++;
 330         spin_unlock_irqrestore(&wl->wl_lock, flags);
 331 }
 332
 333 void wl1271_tx_work_locked(struct wl1271 *wl)
 334 {
 335         struct sk_buff *skb;
 336         bool woken_up = false;
 337         u32 sta_rates = 0;
 338         u32 buf_offset = 0;
 339         bool sent_packets = false;
 340         int ret;
 341
 342         /* check if the rates supported by the AP have changed */
 343         if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED,
 344                                         &wl->flags))) {
 345                 unsigned long flags;
 346
 347                 spin_lock_irqsave(&wl->wl_lock, flags);
 348                 sta_rates = wl->sta_rate_set;
 349                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 350         }
 351
 352         if (unlikely(wl->state == WL1271_STATE_OFF))
 353                 goto out;
 354
 355         /* if rates have changed, re-configure the rate policy */
 356         if (unlikely(sta_rates)) {
 357                 ret = wl1271_ps_elp_wakeup(wl, false);
 358                 if (ret < 0)
 359                         goto out;
 360                 woken_up = true;
 361
 362                 wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
 363                 wl1271_acx_sta_rate_policies(wl);
 364         }
 365
 366         while ((skb = wl1271_skb_dequeue(wl))) {
 367                 if (!woken_up) {
 368                         ret = wl1271_ps_elp_wakeup(wl, false);
 369                         if (ret < 0)
 370                                 goto out_ack;
 371                         woken_up = true;
 372                 }
 373
 374                 ret = wl1271_prepare_tx_frame(wl, skb, buf_offset);
 375                 if (ret == -EAGAIN) {
 376                         /*
 377                          * Aggregation buffer is full.
 378                          * Flush buffer and try again.
 379                          */
 380                         wl1271_skb_queue_head(wl, skb);
 381                         wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
 382                                      buf_offset, true);
 383                         sent_packets = true;
 384                         buf_offset = 0;
 385                         continue;
 386                 } else if (ret == -EBUSY) {
 387                         /*
 388                          * Firmware buffer is full.
 389                          * Queue back last skb, and stop aggregating.
 390                          */
 391                         wl1271_skb_queue_head(wl, skb);
 392                         /* No work left, avoid scheduling redundant tx work */
 393                         set_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags);
 394                         goto out_ack;
 395                 } else if (ret < 0) {
 396                         dev_kfree_skb(skb);
 397                         goto out_ack;
 398                 }
 399                 buf_offset += ret;
 400                 wl->tx_packets_count++;
 401         }
 402
 403 out_ack:
 404         if (buf_offset) {
 405                 wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
 406                                 buf_offset, true);
 407                 sent_packets = true;
 408         }
 409         if (sent_packets) {
 410                 /* interrupt the firmware with the new packets */
 411                 wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 412                 handle_tx_low_watermark(wl);
 413         }
 414
 415 out:
 416         if (woken_up)
 417                 wl1271_ps_elp_sleep(wl);
 418 }
 419
 420 void wl1271_tx_work(struct work_struct *work)
 421 {
 422         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 423
 424         mutex_lock(&wl->mutex);
 425         wl1271_tx_work_locked(wl);
 426         mutex_unlock(&wl->mutex);
 427 }
 428
 429 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 430                                       struct wl1271_tx_hw_res_descr *result)
 431 {
 432         struct ieee80211_tx_info *info;
 433         struct sk_buff *skb;
 434         int id = result->id;
 435         int rate = -1;
 436         u8 retries = 0;
 437
 438         /* check for id legality */
 439         if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) {
 440                 wl1271_warning("TX result illegal id: %d", id);
 441                 return;
 442         }
 443
 444         skb = wl->tx_frames[id];
 445         info = IEEE80211_SKB_CB(skb);
 446
 447         /* update the TX status info */
 448         if (result->status == TX_SUCCESS) {
 449                 if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
 450                         info->flags |= IEEE80211_TX_STAT_ACK;
 451                 rate = wl1271_rate_to_idx(result->rate_class_index, wl->band);
 452                 retries = result->ack_failures;
 453         } else if (result->status == TX_RETRY_EXCEEDED) {
 454                 wl->stats.excessive_retries++;
 455                 retries = result->ack_failures;
 456         }
 457
 458         info->status.rates[0].idx = rate;
 459         info->status.rates[0].count = retries;
 460         info->status.rates[0].flags = 0;
 461         info->status.ack_signal = -1;
 462
 463         wl->stats.retry_count += result->ack_failures;
 464
 465         /* update security sequence number */
 466         wl->tx_security_seq += (result->lsb_security_sequence_number -
 467                                 wl->tx_security_last_seq);
 468         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 469
 470         /* remove private header from packet */
 471         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 472
 473         /* remove TKIP header space if present */
 474         if (info->control.hw_key &&
 475             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 476                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 477                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 478                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 479         }
 480
 481         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 482                      " status 0x%x",
 483                      result->id, skb, result->ack_failures,
 484                      result->rate_class_index, result->status);
 485
 486         /* return the packet to the stack */
 487         ieee80211_tx_status(wl->hw, skb);
 488         wl1271_free_tx_id(wl, result->id);
 489 }
 490
 491 /* Called upon reception of a TX complete interrupt */
 492 void wl1271_tx_complete(struct wl1271 *wl)
 493 {
 494         struct wl1271_acx_mem_map *memmap =
 495                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 496         u32 count, fw_counter;
 497         u32 i;
 498
 499         /* read the tx results from the chipset */
 500         wl1271_read(wl, le32_to_cpu(memmap->tx_result),
 501                     wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 502         fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter);
 503
 504         /* write host counter to chipset (to ack) */
 505         wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
 506                        offsetof(struct wl1271_tx_hw_res_if,
 507                                 tx_result_host_counter), fw_counter);
 508
 509         count = fw_counter - wl->tx_results_count;
 510         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 511
 512         /* verify that the result buffer is not getting overrun */
 513         if (unlikely(count > TX_HW_RESULT_QUEUE_LEN))
 514                 wl1271_warning("TX result overflow from chipset: %d", count);
 515
 516         /* process the results */
 517         for (i = 0; i < count; i++) {
 518                 struct wl1271_tx_hw_res_descr *result;
 519                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 520
 521                 /* process the packet */
 522                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 523                 wl1271_tx_complete_packet(wl, result);
 524
 525                 wl->tx_results_count++;
 526         }
 527 }
 528
 529 /* caller must hold wl->mutex */
 530 void wl1271_tx_reset(struct wl1271 *wl)
 531 {
 532         int i;
 533         struct sk_buff *skb;
 534
 535         /* TX failure */
 536         for (i = 0; i < NUM_TX_QUEUES; i++) {
 537                 while ((skb = skb_dequeue(&wl->tx_queue[i]))) {
 538                         wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb);
 539                         ieee80211_tx_status(wl->hw, skb);
 540                 }
 541         }
 542         wl->tx_queue_count = 0;
 543
 544         /*
 545          * Make sure the driver is at a consistent state, in case this
 546          * function is called from a context other than interface removal.
 547          */
 548         handle_tx_low_watermark(wl);
 549
 550         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 551                 if (wl->tx_frames[i] != NULL) {
 552                         skb = wl->tx_frames[i];
 553                         wl1271_free_tx_id(wl, i);
 554                         wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb);
 555                         ieee80211_tx_status(wl->hw, skb);
 556                 }
 557 }
 558
 559 #define WL1271_TX_FLUSH_TIMEOUT 500000
 560
 561 /* caller must *NOT* hold wl->mutex */
 562 void wl1271_tx_flush(struct wl1271 *wl)
 563 {
 564         unsigned long timeout;
 565         timeout = jiffies + usecs_to_jiffies(WL1271_TX_FLUSH_TIMEOUT);
 566
 567         while (!time_after(jiffies, timeout)) {
 568                 mutex_lock(&wl->mutex);
 569                 wl1271_debug(DEBUG_TX, "flushing tx buffer: %d",
 570                              wl->tx_frames_cnt);
 571                 if ((wl->tx_frames_cnt == 0) && (wl->tx_queue_count == 0)) {
 572                         mutex_unlock(&wl->mutex);
 573                         return;
 574                 }
 575                 mutex_unlock(&wl->mutex);
 576                 msleep(1);
 577         }
 578
 579         wl1271_warning("Unable to flush all TX buffers, timed out.");
 580 }
 581
 582 u32 wl1271_tx_min_rate_get(struct wl1271 *wl)
 583 {
 584         int i;
 585         u32 rate = 0;
 586
 587         if (!wl->basic_rate_set) {
 588                 WARN_ON(1);
 589                 wl->basic_rate_set = wl->conf.tx.basic_rate;
 590         }
 591
 592         for (i = 0; !rate; i++) {
 593                 if ((wl->basic_rate_set >> i) & 0x1)
 594                         rate = 1 << i;
 595         }
 596
 597         return rate;
 598 }