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