drivers/net/wireless/wl12xx/wl1271_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
  27 #include "wl1271.h"
  28 #include "wl1271_io.h"
  29 #include "wl1271_reg.h"
  30 #include "wl1271_ps.h"
  31 #include "wl1271_tx.h"
  32
  33 static int wl1271_tx_id(struct wl1271 *wl, struct sk_buff *skb)
  34 {
  35         int i;
  36         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
  37                 if (wl->tx_frames[i] == NULL) {
  38                         wl->tx_frames[i] = skb;
  39                         return i;
  40                 }
  41
  42         return -EBUSY;
  43 }
  44
  45 static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
  46 {
  47         struct wl1271_tx_hw_descr *desc;
  48         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
  49         u32 total_blocks, excluded;
  50         int id, ret = -EBUSY;
  51
  52         /* allocate free identifier for the packet */
  53         id = wl1271_tx_id(wl, skb);
  54         if (id < 0)
  55                 return id;
  56
  57         /* approximate the number of blocks required for this packet
  58            in the firmware */
  59         /* FIXME: try to figure out what is done here and make it cleaner */
  60         total_blocks = (total_len + 20) >> TX_HW_BLOCK_SHIFT_DIV;
  61         excluded = (total_blocks << 2) + ((total_len + 20) & 0xff) + 34;
  62         total_blocks += (excluded > 252) ? 2 : 1;
  63         total_blocks += TX_HW_BLOCK_SPARE;
  64
  65         if (total_blocks <= wl->tx_blocks_available) {
  66                 desc = (struct wl1271_tx_hw_descr *)skb_push(
  67                         skb, total_len - skb->len);
  68
  69                 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
  70                 desc->total_mem_blocks = total_blocks;
  71                 desc->id = id;
  72
  73                 wl->tx_blocks_available -= total_blocks;
  74
  75                 ret = 0;
  76
  77                 wl1271_debug(DEBUG_TX,
  78                              "tx_allocate: size: %d, blocks: %d, id: %d",
  79                              total_len, total_blocks, id);
  80         } else
  81                 wl->tx_frames[id] = NULL;
  82
  83         return ret;
  84 }
  85
  86 static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
  87                               u32 extra, struct ieee80211_tx_info *control)
  88 {
  89         struct timespec ts;
  90         struct wl1271_tx_hw_descr *desc;
  91         int pad, ac;
  92         s64 hosttime;
  93         u16 tx_attr;
  94
  95         desc = (struct wl1271_tx_hw_descr *) skb->data;
  96
  97         /* relocate space for security header */
  98         if (extra) {
  99                 void *framestart = skb->data + sizeof(*desc);
 100                 u16 fc = *(u16 *)(framestart + extra);
 101                 int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
 102                 memmove(framestart, framestart + extra, hdrlen);
 103         }
 104
 105         /* configure packet life time */
 106         getnstimeofday(&ts);
 107         hosttime = (timespec_to_ns(&ts) >> 10);
 108         desc->start_time = cpu_to_le32(hosttime - wl->time_offset);
 109         desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
 110
 111         /* configure the tx attributes */
 112         tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 113
 114         /* queue */
 115         ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
 116         desc->tid = wl1271_tx_ac_to_tid(ac);
 117
 118         desc->aid = TX_HW_DEFAULT_AID;
 119         desc->reserved = 0;
 120
 121         /* align the length (and store in terms of words) */
 122         pad = WL1271_TX_ALIGN(skb->len);
 123         desc->length = cpu_to_le16(pad >> 2);
 124
 125         /* calculate number of padding bytes */
 126         pad = pad - skb->len;
 127         tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 128
 129         /* if the packets are destined for AP (have a STA entry) send them
 130            with AP rate policies, otherwise use default basic rates */
 131         if (control->control.sta)
 132                 tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY;
 133
 134         desc->tx_attr = cpu_to_le16(tx_attr);
 135
 136         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 137         return 0;
 138 }
 139
 140 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 141                                  struct ieee80211_tx_info *control)
 142 {
 143
 144         struct wl1271_tx_hw_descr *desc;
 145         int len;
 146
 147         /* FIXME: This is a workaround for getting non-aligned packets.
 148            This happens at least with EAPOL packets from the user space.
 149            Our DMA requires packets to be aligned on a 4-byte boundary.
 150         */
 151         if (unlikely((long)skb->data & 0x03)) {
 152                 int offset = (4 - (long)skb->data) & 0x03;
 153                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 154
 155                 /* check whether the current skb can be used */
 156                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 157                         unsigned char *src = skb->data;
 158
 159                         /* align the buffer on a 4-byte boundary */
 160                         skb_reserve(skb, offset);
 161                         memmove(skb->data, src, skb->len);
 162                 } else {
 163                         wl1271_info("No handler, fixme!");
 164                         return -EINVAL;
 165                 }
 166         }
 167
 168         len = WL1271_TX_ALIGN(skb->len);
 169
 170         /* perform a fixed address block write with the packet */
 171         wl1271_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 172
 173         /* write packet new counter into the write access register */
 174         wl->tx_packets_count++;
 175
 176         desc = (struct wl1271_tx_hw_descr *) skb->data;
 177         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 178                      desc->id, skb, len, desc->length);
 179
 180         return 0;
 181 }
 182
 183 /* caller must hold wl->mutex */
 184 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 185 {
 186         struct ieee80211_tx_info *info;
 187         u32 extra = 0;
 188         int ret = 0;
 189         u8 idx;
 190
 191         if (!skb)
 192                 return -EINVAL;
 193
 194         info = IEEE80211_SKB_CB(skb);
 195
 196         if (info->control.hw_key &&
 197             info->control.hw_key->alg == ALG_TKIP)
 198                 extra = WL1271_TKIP_IV_SPACE;
 199
 200         if (info->control.hw_key) {
 201                 idx = info->control.hw_key->hw_key_idx;
 202
 203                 /* FIXME: do we have to do this if we're not using WEP? */
 204                 if (unlikely(wl->default_key != idx)) {
 205                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 206                         if (ret < 0)
 207                                 return ret;
 208                         wl->default_key = idx;
 209                 }
 210         }
 211
 212         ret = wl1271_tx_allocate(wl, skb, extra);
 213         if (ret < 0)
 214                 return ret;
 215
 216         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 217         if (ret < 0)
 218                 return ret;
 219
 220         ret = wl1271_tx_send_packet(wl, skb, info);
 221         if (ret < 0)
 222                 return ret;
 223
 224         return ret;
 225 }
 226
 227 static u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
 228 {
 229         struct ieee80211_supported_band *band;
 230         u32 enabled_rates = 0;
 231         int bit;
 232
 233         band = wl->hw->wiphy->bands[wl->band];
 234         for (bit = 0; bit < band->n_bitrates; bit++) {
 235                 if (rate_set & 0x1)
 236                         enabled_rates |= band->bitrates[bit].hw_value;
 237                 rate_set >>= 1;
 238         }
 239
 240         return enabled_rates;
 241 }
 242
 243 void wl1271_tx_work(struct work_struct *work)
 244 {
 245         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 246         struct sk_buff *skb;
 247         bool woken_up = false;
 248         u32 sta_rates = 0;
 249         u32 prev_tx_packets_count;
 250         int ret;
 251
 252         /* check if the rates supported by the AP have changed */
 253         if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED,
 254                                         &wl->flags))) {
 255                 unsigned long flags;
 256                 spin_lock_irqsave(&wl->wl_lock, flags);
 257                 sta_rates = wl->sta_rate_set;
 258                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 259         }
 260
 261         mutex_lock(&wl->mutex);
 262
 263         if (unlikely(wl->state == WL1271_STATE_OFF))
 264                 goto out;
 265
 266         prev_tx_packets_count = wl->tx_packets_count;
 267
 268         /* if rates have changed, re-configure the rate policy */
 269         if (unlikely(sta_rates)) {
 270                 wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
 271                 wl1271_acx_rate_policies(wl);
 272         }
 273
 274         while ((skb = skb_dequeue(&wl->tx_queue))) {
 275                 if (!woken_up) {
 276                         ret = wl1271_ps_elp_wakeup(wl, false);
 277                         if (ret < 0)
 278                                 goto out_ack;
 279                         woken_up = true;
 280                 }
 281
 282                 ret = wl1271_tx_frame(wl, skb);
 283                 if (ret == -EBUSY) {
 284                         /* firmware buffer is full, lets stop transmitting. */
 285                         skb_queue_head(&wl->tx_queue, skb);
 286                         goto out_ack;
 287                 } else if (ret < 0) {
 288                         dev_kfree_skb(skb);
 289                         goto out_ack;
 290                 }
 291         }
 292
 293 out_ack:
 294         /* interrupt the firmware with the new packets */
 295         if (prev_tx_packets_count != wl->tx_packets_count)
 296                 wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 297
 298 out:
 299         if (woken_up)
 300                 wl1271_ps_elp_sleep(wl);
 301
 302         mutex_unlock(&wl->mutex);
 303 }
 304
 305 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 306                                       struct wl1271_tx_hw_res_descr *result)
 307 {
 308         struct ieee80211_tx_info *info;
 309         struct sk_buff *skb;
 310         u16 seq;
 311         int id = result->id;
 312
 313         /* check for id legality */
 314         if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) {
 315                 wl1271_warning("TX result illegal id: %d", id);
 316                 return;
 317         }
 318
 319         skb = wl->tx_frames[id];
 320         info = IEEE80211_SKB_CB(skb);
 321
 322         /* update packet status */
 323         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 324                 if (result->status == TX_SUCCESS)
 325                         info->flags |= IEEE80211_TX_STAT_ACK;
 326                 if (result->status & TX_RETRY_EXCEEDED) {
 327                         /* FIXME */
 328                         /* info->status.excessive_retries = 1; */
 329                         wl->stats.excessive_retries++;
 330                 }
 331         }
 332
 333         /* FIXME */
 334         /* info->status.retry_count = result->ack_failures; */
 335         wl->stats.retry_count += result->ack_failures;
 336
 337         /* update security sequence number */
 338         seq = wl->tx_security_seq_16 +
 339                 (result->lsb_security_sequence_number -
 340                  wl->tx_security_last_seq);
 341         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 342
 343         if (seq < wl->tx_security_seq_16)
 344                 wl->tx_security_seq_32++;
 345         wl->tx_security_seq_16 = seq;
 346
 347         /* remove private header from packet */
 348         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 349
 350         /* remove TKIP header space if present */
 351         if (info->control.hw_key &&
 352             info->control.hw_key->alg == ALG_TKIP) {
 353                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 354                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 355                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 356         }
 357
 358         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 359                      " status 0x%x",
 360                      result->id, skb, result->ack_failures,
 361                      result->rate_class_index, result->status);
 362
 363         /* return the packet to the stack */
 364         ieee80211_tx_status(wl->hw, skb);
 365         wl->tx_frames[result->id] = NULL;
 366 }
 367
 368 /* Called upon reception of a TX complete interrupt */
 369 void wl1271_tx_complete(struct wl1271 *wl)
 370 {
 371         struct wl1271_acx_mem_map *memmap =
 372                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 373         u32 count, fw_counter;
 374         u32 i;
 375
 376         /* read the tx results from the chipset */
 377         wl1271_read(wl, le32_to_cpu(memmap->tx_result),
 378                     wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 379         fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter);
 380
 381         /* write host counter to chipset (to ack) */
 382         wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
 383                        offsetof(struct wl1271_tx_hw_res_if,
 384                                 tx_result_host_counter), fw_counter);
 385
 386         count = fw_counter - wl->tx_results_count;
 387         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 388
 389         /* verify that the result buffer is not getting overrun */
 390         if (unlikely(count > TX_HW_RESULT_QUEUE_LEN))
 391                 wl1271_warning("TX result overflow from chipset: %d", count);
 392
 393         /* process the results */
 394         for (i = 0; i < count; i++) {
 395                 struct wl1271_tx_hw_res_descr *result;
 396                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 397
 398                 /* process the packet */
 399                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 400                 wl1271_tx_complete_packet(wl, result);
 401
 402                 wl->tx_results_count++;
 403         }
 404
 405         if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) &&
 406             skb_queue_len(&wl->tx_queue) <= WL1271_TX_QUEUE_LOW_WATERMARK) {
 407                 unsigned long flags;
 408
 409                 /* firmware buffer has space, restart queues */
 410                 wl1271_debug(DEBUG_TX, "tx_complete: waking queues");
 411                 spin_lock_irqsave(&wl->wl_lock, flags);
 412                 ieee80211_wake_queues(wl->hw);
 413                 clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
 414                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 415                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 416         }
 417 }
 418
 419 /* caller must hold wl->mutex */
 420 void wl1271_tx_flush(struct wl1271 *wl)
 421 {
 422         int i;
 423         struct sk_buff *skb;
 424         struct ieee80211_tx_info *info;
 425
 426         /* TX failure */
 427 /*      control->flags = 0; FIXME */
 428
 429         while ((skb = skb_dequeue(&wl->tx_queue))) {
 430                 info = IEEE80211_SKB_CB(skb);
 431
 432                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 433
 434                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 435                                 continue;
 436
 437                 ieee80211_tx_status(wl->hw, skb);
 438         }
 439
 440         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 441                 if (wl->tx_frames[i] != NULL) {
 442                         skb = wl->tx_frames[i];
 443                         info = IEEE80211_SKB_CB(skb);
 444
 445                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 446                                 continue;
 447
 448                         ieee80211_tx_status(wl->hw, skb);
 449                         wl->tx_frames[i] = NULL;
 450                 }
 451 }