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_spi.h"
  29 #include "wl1271_io.h"
  30 #include "wl1271_reg.h"
  31 #include "wl1271_ps.h"
  32 #include "wl1271_tx.h"
  33
  34 static int wl1271_tx_id(struct wl1271 *wl, struct sk_buff *skb)
  35 {
  36         int i;
  37         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
  38                 if (wl->tx_frames[i] == NULL) {
  39                         wl->tx_frames[i] = skb;
  40                         return i;
  41                 }
  42
  43         return -EBUSY;
  44 }
  45
  46 static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
  47 {
  48         struct wl1271_tx_hw_descr *desc;
  49         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
  50         u32 total_blocks, excluded;
  51         int id, ret = -EBUSY;
  52
  53         /* allocate free identifier for the packet */
  54         id = wl1271_tx_id(wl, skb);
  55         if (id < 0)
  56                 return id;
  57
  58         /* approximate the number of blocks required for this packet
  59            in the firmware */
  60         /* FIXME: try to figure out what is done here and make it cleaner */
  61         total_blocks = (total_len + 20) >> TX_HW_BLOCK_SHIFT_DIV;
  62         excluded = (total_blocks << 2) + ((total_len + 20) & 0xff) + 34;
  63         total_blocks += (excluded > 252) ? 2 : 1;
  64         total_blocks += TX_HW_BLOCK_SPARE;
  65
  66         if (total_blocks <= wl->tx_blocks_available) {
  67                 desc = (struct wl1271_tx_hw_descr *)skb_push(
  68                         skb, total_len - skb->len);
  69
  70                 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
  71                 desc->total_mem_blocks = total_blocks;
  72                 desc->id = id;
  73
  74                 wl->tx_blocks_available -= total_blocks;
  75
  76                 ret = 0;
  77
  78                 wl1271_debug(DEBUG_TX,
  79                              "tx_allocate: size: %d, blocks: %d, id: %d",
  80                              total_len, total_blocks, id);
  81         } else
  82                 wl->tx_frames[id] = NULL;
  83
  84         return ret;
  85 }
  86
  87 static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
  88                               u32 extra, struct ieee80211_tx_info *control)
  89 {
  90         struct wl1271_tx_hw_descr *desc;
  91         int pad, ac;
  92         u16 tx_attr;
  93
  94         desc = (struct wl1271_tx_hw_descr *) skb->data;
  95
  96         /* relocate space for security header */
  97         if (extra) {
  98                 void *framestart = skb->data + sizeof(*desc);
  99                 u16 fc = *(u16 *)(framestart + extra);
 100                 int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
 101                 memmove(framestart, framestart + extra, hdrlen);
 102         }
 103
 104         /* configure packet life time */
 105         desc->start_time = cpu_to_le32(jiffies_to_usecs(jiffies) -
 106                                        wl->time_offset);
 107         desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
 108
 109         /* configure the tx attributes */
 110         tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 111
 112         /* queue */
 113         ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
 114         desc->tid = wl1271_tx_ac_to_tid(ac);
 115
 116         desc->aid = TX_HW_DEFAULT_AID;
 117         desc->reserved = 0;
 118
 119         /* align the length (and store in terms of words) */
 120         pad = WL1271_TX_ALIGN(skb->len);
 121         desc->length = cpu_to_le16(pad >> 2);
 122
 123         /* calculate number of padding bytes */
 124         pad = pad - skb->len;
 125         tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 126
 127         /* if the packets are destined for AP (have a STA entry) send them
 128            with AP rate policies, otherwise use default basic rates */
 129         if (control->control.sta)
 130                 tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY;
 131
 132         desc->tx_attr = cpu_to_le16(tx_attr);
 133
 134         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 135         return 0;
 136 }
 137
 138 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 139                                  struct ieee80211_tx_info *control)
 140 {
 141
 142         struct wl1271_tx_hw_descr *desc;
 143         int len;
 144
 145         /* FIXME: This is a workaround for getting non-aligned packets.
 146            This happens at least with EAPOL packets from the user space.
 147            Our DMA requires packets to be aligned on a 4-byte boundary.
 148         */
 149         if (unlikely((long)skb->data & 0x03)) {
 150                 int offset = (4 - (long)skb->data) & 0x03;
 151                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 152
 153                 /* check whether the current skb can be used */
 154                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 155                         unsigned char *src = skb->data;
 156
 157                         /* align the buffer on a 4-byte boundary */
 158                         skb_reserve(skb, offset);
 159                         memmove(skb->data, src, skb->len);
 160                 } else {
 161                         wl1271_info("No handler, fixme!");
 162                         return -EINVAL;
 163                 }
 164         }
 165
 166         len = WL1271_TX_ALIGN(skb->len);
 167
 168         /* perform a fixed address block write with the packet */
 169         wl1271_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 170
 171         /* write packet new counter into the write access register */
 172         wl->tx_packets_count++;
 173         wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 174
 175         desc = (struct wl1271_tx_hw_descr *) skb->data;
 176         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 177                      desc->id, skb, len, desc->length);
 178
 179         return 0;
 180 }
 181
 182 /* caller must hold wl->mutex */
 183 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 184 {
 185         struct ieee80211_tx_info *info;
 186         u32 extra = 0;
 187         int ret = 0;
 188         u8 idx;
 189
 190         if (!skb)
 191                 return -EINVAL;
 192
 193         info = IEEE80211_SKB_CB(skb);
 194
 195         if (info->control.hw_key &&
 196             info->control.hw_key->alg == ALG_TKIP)
 197                 extra = WL1271_TKIP_IV_SPACE;
 198
 199         if (info->control.hw_key) {
 200                 idx = info->control.hw_key->hw_key_idx;
 201
 202                 /* FIXME: do we have to do this if we're not using WEP? */
 203                 if (unlikely(wl->default_key != idx)) {
 204                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 205                         if (ret < 0)
 206                                 return ret;
 207                         wl->default_key = idx;
 208                 }
 209         }
 210
 211         ret = wl1271_tx_allocate(wl, skb, extra);
 212         if (ret < 0)
 213                 return ret;
 214
 215         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 216         if (ret < 0)
 217                 return ret;
 218
 219         ret = wl1271_tx_send_packet(wl, skb, info);
 220         if (ret < 0)
 221                 return ret;
 222
 223         return ret;
 224 }
 225
 226 static u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
 227 {
 228         struct ieee80211_supported_band *band;
 229         u32 enabled_rates = 0;
 230         int bit;
 231
 232         band = wl->hw->wiphy->bands[wl->band];
 233         for (bit = 0; bit < band->n_bitrates; bit++) {
 234                 if (rate_set & 0x1)
 235                         enabled_rates |= band->bitrates[bit].hw_value;
 236                 rate_set >>= 1;
 237         }
 238
 239         return enabled_rates;
 240 }
 241
 242 void wl1271_tx_work(struct work_struct *work)
 243 {
 244         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 245         struct sk_buff *skb;
 246         bool woken_up = false;
 247         u32 sta_rates = 0;
 248         int ret;
 249
 250         /* check if the rates supported by the AP have changed */
 251         if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED,
 252                                         &wl->flags))) {
 253                 unsigned long flags;
 254                 spin_lock_irqsave(&wl->wl_lock, flags);
 255                 sta_rates = wl->sta_rate_set;
 256                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 257         }
 258
 259         mutex_lock(&wl->mutex);
 260
 261         if (unlikely(wl->state == WL1271_STATE_OFF))
 262                 goto out;
 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;
 275                         woken_up = true;
 276                 }
 277
 278                 ret = wl1271_tx_frame(wl, skb);
 279                 if (ret == -EBUSY) {
 280                         /* firmware buffer is full, stop queues */
 281                         wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
 282                                      "stop queues");
 283                         ieee80211_stop_queues(wl->hw);
 284                         set_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
 285                         skb_queue_head(&wl->tx_queue, skb);
 286                         goto out;
 287                 } else if (ret < 0) {
 288                         dev_kfree_skb(skb);
 289                         goto out;
 290                 } else if (test_and_clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED,
 291                                               &wl->flags)) {
 292                         /* firmware buffer has space, restart queues */
 293                         wl1271_debug(DEBUG_TX,
 294                                      "complete_packet: waking queues");
 295                         ieee80211_wake_queues(wl->hw);
 296                 }
 297         }
 298
 299 out:
 300         if (woken_up)
 301                 wl1271_ps_elp_sleep(wl);
 302
 303         mutex_unlock(&wl->mutex);
 304 }
 305
 306 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 307                                       struct wl1271_tx_hw_res_descr *result)
 308 {
 309         struct ieee80211_tx_info *info;
 310         struct sk_buff *skb;
 311         u16 seq;
 312         int id = result->id;
 313
 314         /* check for id legality */
 315         if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
 316                 wl1271_warning("TX result illegal id: %d", id);
 317                 return;
 318         }
 319
 320         skb = wl->tx_frames[id];
 321         info = IEEE80211_SKB_CB(skb);
 322
 323         /* update packet status */
 324         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 325                 if (result->status == TX_SUCCESS)
 326                         info->flags |= IEEE80211_TX_STAT_ACK;
 327                 if (result->status & TX_RETRY_EXCEEDED) {
 328                         /* FIXME */
 329                         /* info->status.excessive_retries = 1; */
 330                         wl->stats.excessive_retries++;
 331                 }
 332         }
 333
 334         /* FIXME */
 335         /* info->status.retry_count = result->ack_failures; */
 336         wl->stats.retry_count += result->ack_failures;
 337
 338         /* update security sequence number */
 339         seq = wl->tx_security_seq_16 +
 340                 (result->lsb_security_sequence_number -
 341                  wl->tx_security_last_seq);
 342         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 343
 344         if (seq < wl->tx_security_seq_16)
 345                 wl->tx_security_seq_32++;
 346         wl->tx_security_seq_16 = seq;
 347
 348         /* remove private header from packet */
 349         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 350
 351         /* remove TKIP header space if present */
 352         if (info->control.hw_key &&
 353             info->control.hw_key->alg == ALG_TKIP) {
 354                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 355                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 356                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 357         }
 358
 359         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 360                      " status 0x%x",
 361                      result->id, skb, result->ack_failures,
 362                      result->rate_class_index, result->status);
 363
 364         /* return the packet to the stack */
 365         ieee80211_tx_status(wl->hw, skb);
 366         wl->tx_frames[result->id] = NULL;
 367 }
 368
 369 /* Called upon reception of a TX complete interrupt */
 370 void wl1271_tx_complete(struct wl1271 *wl, u32 count)
 371 {
 372         struct wl1271_acx_mem_map *memmap =
 373                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 374         u32 i;
 375
 376         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 377
 378         /* read the tx results from the chipset */
 379         wl1271_read(wl, le32_to_cpu(memmap->tx_result),
 380                     wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 381
 382         /* verify that the result buffer is not getting overrun */
 383         if (count > TX_HW_RESULT_QUEUE_LEN) {
 384                 wl1271_warning("TX result overflow from chipset: %d", count);
 385                 count = TX_HW_RESULT_QUEUE_LEN;
 386         }
 387
 388         /* process the results */
 389         for (i = 0; i < count; i++) {
 390                 struct wl1271_tx_hw_res_descr *result;
 391                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 392
 393                 /* process the packet */
 394                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 395                 wl1271_tx_complete_packet(wl, result);
 396
 397                 wl->tx_results_count++;
 398         }
 399
 400         /* write host counter to chipset (to ack) */
 401         wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
 402                        offsetof(struct wl1271_tx_hw_res_if,
 403                        tx_result_host_counter),
 404                        le32_to_cpu(wl->tx_res_if->tx_result_fw_counter));
 405 }
 406
 407 /* caller must hold wl->mutex */
 408 void wl1271_tx_flush(struct wl1271 *wl)
 409 {
 410         int i;
 411         struct sk_buff *skb;
 412         struct ieee80211_tx_info *info;
 413
 414         /* TX failure */
 415 /*      control->flags = 0; FIXME */
 416
 417         while ((skb = skb_dequeue(&wl->tx_queue))) {
 418                 info = IEEE80211_SKB_CB(skb);
 419
 420                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 421
 422                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 423                                 continue;
 424
 425                 ieee80211_tx_status(wl->hw, skb);
 426         }
 427
 428         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 429                 if (wl->tx_frames[i] != NULL) {
 430                         skb = wl->tx_frames[i];
 431                         info = IEEE80211_SKB_CB(skb);
 432
 433                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 434                                 continue;
 435
 436                         ieee80211_tx_status(wl->hw, skb);
 437                         wl->tx_frames[i] = NULL;
 438                 }
 439 }