drivers/net/wireless/iwlwifi/iwl-3945-rs.c

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2007 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  * James P. Ketrenos <ipw2100-admin@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/wireless.h>
  31 #include <net/mac80211.h>
  32 #include <net/ieee80211.h>
  33
  34 #include <linux/netdevice.h>
  35 #include <linux/etherdevice.h>
  36 #include <linux/delay.h>
  37
  38 #include <linux/workqueue.h>
  39
  40 #include "../net/mac80211/ieee80211_rate.h"
  41
  42 #include "iwl-3945.h"
  43
  44 #define RS_NAME "iwl-3945-rs"
  45
  46 struct iwl3945_rate_scale_data {
  47         u64 data;
  48         s32 success_counter;
  49         s32 success_ratio;
  50         s32 counter;
  51         s32 average_tpt;
  52         unsigned long stamp;
  53 };
  54
  55 struct iwl3945_rs_sta {
  56         spinlock_t lock;
  57         s32 *expected_tpt;
  58         unsigned long last_partial_flush;
  59         unsigned long last_flush;
  60         u32 flush_time;
  61         u32 last_tx_packets;
  62         u32 tx_packets;
  63         u8 tgg;
  64         u8 flush_pending;
  65         u8 start_rate;
  66         u8 ibss_sta_added;
  67         struct timer_list rate_scale_flush;
  68         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  69 };
  70
  71 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  72         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  73 };
  74
  75 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  76         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  77 };
  78
  79 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  80         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  81 };
  82
  83 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  84         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  85 };
  86
  87 struct iwl3945_tpt_entry {
  88         s8 min_rssi;
  89         u8 index;
  90 };
  91
  92 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  93         {-60, IWL_RATE_54M_INDEX},
  94         {-64, IWL_RATE_48M_INDEX},
  95         {-72, IWL_RATE_36M_INDEX},
  96         {-80, IWL_RATE_24M_INDEX},
  97         {-84, IWL_RATE_18M_INDEX},
  98         {-85, IWL_RATE_12M_INDEX},
  99         {-87, IWL_RATE_9M_INDEX},
 100         {-89, IWL_RATE_6M_INDEX}
 101 };
 102
 103 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 104         {-60, IWL_RATE_54M_INDEX},
 105         {-64, IWL_RATE_48M_INDEX},
 106         {-68, IWL_RATE_36M_INDEX},
 107         {-80, IWL_RATE_24M_INDEX},
 108         {-84, IWL_RATE_18M_INDEX},
 109         {-85, IWL_RATE_12M_INDEX},
 110         {-86, IWL_RATE_11M_INDEX},
 111         {-88, IWL_RATE_5M_INDEX},
 112         {-90, IWL_RATE_2M_INDEX},
 113         {-92, IWL_RATE_1M_INDEX}
 114 };
 115
 116 #define IWL_RATE_MAX_WINDOW          62
 117 #define IWL_RATE_FLUSH        (3*HZ/10)
 118 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 119 #define IWL_RATE_HIGH_TH          11520
 120 #define IWL_RATE_MIN_FAILURE_TH       8
 121 #define IWL_RATE_MIN_SUCCESS_TH       8
 122 #define IWL_RATE_DECREASE_TH       1920
 123
 124 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 125 {
 126         u32 index = 0;
 127         u32 table_size = 0;
 128         struct iwl3945_tpt_entry *tpt_table = NULL;
 129
 130         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 131                 rssi = IWL_MIN_RSSI_VAL;
 132
 133         switch (band) {
 134         case IEEE80211_BAND_2GHZ:
 135                 tpt_table = iwl3945_tpt_table_g;
 136                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 137                 break;
 138
 139         case IEEE80211_BAND_5GHZ:
 140                 tpt_table = iwl3945_tpt_table_a;
 141                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 142                 break;
 143
 144         default:
 145                 BUG();
 146                 break;
 147         }
 148
 149         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 150                 index++;
 151
 152         index = min(index, (table_size - 1));
 153
 154         return tpt_table[index].index;
 155 }
 156
 157 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 158 {
 159         window->data = 0;
 160         window->success_counter = 0;
 161         window->success_ratio = IWL_INVALID_VALUE;
 162         window->counter = 0;
 163         window->average_tpt = IWL_INVALID_VALUE;
 164         window->stamp = 0;
 165 }
 166
 167 /**
 168  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 169  *
 170  * Returns the number of windows that have gathered data but were
 171  * not flushed.  If there were any that were not flushed, then
 172  * reschedule the rate flushing routine.
 173  */
 174 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 175 {
 176         int unflushed = 0;
 177         int i;
 178         unsigned long flags;
 179
 180         /*
 181          * For each rate, if we have collected data on that rate
 182          * and it has been more than IWL_RATE_WIN_FLUSH
 183          * since we flushed, clear out the gathered statistics
 184          */
 185         for (i = 0; i < IWL_RATE_COUNT; i++) {
 186                 if (!rs_sta->win[i].counter)
 187                         continue;
 188
 189                 spin_lock_irqsave(&rs_sta->lock, flags);
 190                 if (time_after(jiffies, rs_sta->win[i].stamp +
 191                                IWL_RATE_WIN_FLUSH)) {
 192                         IWL_DEBUG_RATE("flushing %d samples of rate "
 193                                        "index %d\n",
 194                                        rs_sta->win[i].counter, i);
 195                         iwl3945_clear_window(&rs_sta->win[i]);
 196                 } else
 197                         unflushed++;
 198                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 199         }
 200
 201         return unflushed;
 202 }
 203
 204 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 205 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 206
 207 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 208 {
 209         struct iwl3945_rs_sta *rs_sta = (void *)data;
 210         int unflushed = 0;
 211         unsigned long flags;
 212         u32 packet_count, duration, pps;
 213
 214         IWL_DEBUG_RATE("enter\n");
 215
 216         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 217
 218         spin_lock_irqsave(&rs_sta->lock, flags);
 219
 220         rs_sta->flush_pending = 0;
 221
 222         /* Number of packets Rx'd since last time this timer ran */
 223         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 224
 225         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 226
 227         if (unflushed) {
 228                 duration =
 229                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 230 /*              duration = jiffies_to_msecs(rs_sta->flush_time); */
 231
 232                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 233                                packet_count, duration);
 234
 235                 /* Determine packets per second */
 236                 if (duration)
 237                         pps = (packet_count * 1000) / duration;
 238                 else
 239                         pps = 0;
 240
 241                 if (pps) {
 242                         duration = IWL_RATE_FLUSH_MAX / pps;
 243                         if (duration < IWL_RATE_FLUSH_MIN)
 244                                 duration = IWL_RATE_FLUSH_MIN;
 245                 } else
 246                         duration = IWL_RATE_FLUSH_MAX;
 247
 248                 rs_sta->flush_time = msecs_to_jiffies(duration);
 249
 250                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 251                                duration, packet_count);
 252
 253                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 254                           rs_sta->flush_time);
 255
 256                 rs_sta->last_partial_flush = jiffies;
 257         }
 258
 259         /* If there weren't any unflushed entries, we don't schedule the timer
 260          * to run again */
 261
 262         rs_sta->last_flush = jiffies;
 263
 264         spin_unlock_irqrestore(&rs_sta->lock, flags);
 265
 266         IWL_DEBUG_RATE("leave\n");
 267 }
 268
 269 /**
 270  * iwl3945_collect_tx_data - Update the success/failure sliding window
 271  *
 272  * We keep a sliding window of the last 64 packets transmitted
 273  * at this rate.  window->data contains the bitmask of successful
 274  * packets.
 275  */
 276 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 277                                 struct iwl3945_rate_scale_data *window,
 278                                 int success, int retries)
 279 {
 280         unsigned long flags;
 281
 282         if (!retries) {
 283                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 284                 return;
 285         }
 286
 287         while (retries--) {
 288                 spin_lock_irqsave(&rs_sta->lock, flags);
 289
 290                 /* If we have filled up the window then subtract one from the
 291                  * success counter if the high-bit is counting toward
 292                  * success */
 293                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 294                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 295                                 window->success_counter--;
 296                 } else
 297                         window->counter++;
 298
 299                 /* Slide the window to the left one bit */
 300                 window->data = (window->data << 1);
 301
 302                 /* If this packet was a success then set the low bit high */
 303                 if (success) {
 304                         window->success_counter++;
 305                         window->data |= 1;
 306                 }
 307
 308                 /* window->counter can't be 0 -- it is either >0 or
 309                  * IWL_RATE_MAX_WINDOW */
 310                 window->success_ratio = 12800 * window->success_counter /
 311                     window->counter;
 312
 313                 /* Tag this window as having been updated */
 314                 window->stamp = jiffies;
 315
 316                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 317         }
 318 }
 319
 320 static void rs_rate_init(void *priv_rate, void *priv_sta,
 321                          struct ieee80211_local *local, struct sta_info *sta)
 322 {
 323         int i;
 324
 325         IWL_DEBUG_RATE("enter\n");
 326
 327         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 328          * the lowest or the highest rate.. Could consider using RSSI from
 329          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 330          * after assoc.. */
 331
 332         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 333                 if (sta->supp_rates[local->hw.conf.channel->band] & (1 << i)) {
 334                         sta->txrate_idx = i;
 335                         break;
 336                 }
 337         }
 338
 339         sta->last_txrate_idx = sta->txrate_idx;
 340
 341         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 342         if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ)
 343                 sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 344
 345         IWL_DEBUG_RATE("leave\n");
 346 }
 347
 348 static void *rs_alloc(struct ieee80211_local *local)
 349 {
 350         return local->hw.priv;
 351 }
 352
 353 /* rate scale requires free function to be implemented */
 354 static void rs_free(void *priv)
 355 {
 356         return;
 357 }
 358 static void rs_clear(void *priv)
 359 {
 360         return;
 361 }
 362
 363
 364 static void *rs_alloc_sta(void *priv, gfp_t gfp)
 365 {
 366         struct iwl3945_rs_sta *rs_sta;
 367         int i;
 368
 369         IWL_DEBUG_RATE("enter\n");
 370
 371         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 372         if (!rs_sta) {
 373                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 374                 return NULL;
 375         }
 376
 377         spin_lock_init(&rs_sta->lock);
 378
 379         rs_sta->start_rate = IWL_RATE_INVALID;
 380
 381         /* default to just 802.11b */
 382         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 383
 384         rs_sta->last_partial_flush = jiffies;
 385         rs_sta->last_flush = jiffies;
 386         rs_sta->flush_time = IWL_RATE_FLUSH;
 387         rs_sta->last_tx_packets = 0;
 388         rs_sta->ibss_sta_added = 0;
 389
 390         init_timer(&rs_sta->rate_scale_flush);
 391         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 392         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 393
 394         for (i = 0; i < IWL_RATE_COUNT; i++)
 395                 iwl3945_clear_window(&rs_sta->win[i]);
 396
 397         IWL_DEBUG_RATE("leave\n");
 398
 399         return rs_sta;
 400 }
 401
 402 static void rs_free_sta(void *priv, void *priv_sta)
 403 {
 404         struct iwl3945_rs_sta *rs_sta = priv_sta;
 405
 406         IWL_DEBUG_RATE("enter\n");
 407         del_timer_sync(&rs_sta->rate_scale_flush);
 408         kfree(rs_sta);
 409         IWL_DEBUG_RATE("leave\n");
 410 }
 411
 412
 413 /*
 414  * get ieee prev rate from rate scale table.
 415  * for A and B mode we need to overright prev
 416  * value
 417  */
 418 static int rs_adjust_next_rate(struct iwl3945_priv *priv, int rate)
 419 {
 420         int next_rate = iwl3945_get_prev_ieee_rate(rate);
 421
 422         switch (priv->band) {
 423         case IEEE80211_BAND_5GHZ:
 424                 if (rate == IWL_RATE_12M_INDEX)
 425                         next_rate = IWL_RATE_9M_INDEX;
 426                 else if (rate == IWL_RATE_6M_INDEX)
 427                         next_rate = IWL_RATE_6M_INDEX;
 428                 break;
 429 /* XXX cannot be invoked in current mac80211 so not a regression
 430         case MODE_IEEE80211B:
 431                 if (rate == IWL_RATE_11M_INDEX_TABLE)
 432                         next_rate = IWL_RATE_5M_INDEX_TABLE;
 433                 break;
 434  */
 435         default:
 436                 break;
 437         }
 438
 439         return next_rate;
 440 }
 441 /**
 442  * rs_tx_status - Update rate control values based on Tx results
 443  *
 444  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 445  * the hardware for each rate.
 446  */
 447 static void rs_tx_status(void *priv_rate,
 448                          struct net_device *dev,
 449                          struct sk_buff *skb,
 450                          struct ieee80211_tx_status *tx_resp)
 451 {
 452         u8 retries, current_count;
 453         int scale_rate_index, first_index, last_index;
 454         unsigned long flags;
 455         struct sta_info *sta;
 456         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 457         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 458         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 459         struct iwl3945_rs_sta *rs_sta;
 460         struct ieee80211_supported_band *sband;
 461
 462         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 463
 464         IWL_DEBUG_RATE("enter\n");
 465
 466         retries = tx_resp->retry_count;
 467
 468         first_index = &sband->bitrates[0] - tx_resp->control.tx_rate;
 469         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 470                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 471                 return;
 472         }
 473
 474         sta = sta_info_get(local, hdr->addr1);
 475         if (!sta || !sta->rate_ctrl_priv) {
 476                 if (sta)
 477                         sta_info_put(sta);
 478                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 479                 return;
 480         }
 481
 482         rs_sta = (void *)sta->rate_ctrl_priv;
 483
 484         rs_sta->tx_packets++;
 485
 486         scale_rate_index = first_index;
 487         last_index = first_index;
 488
 489         /*
 490          * Update the window for each rate.  We determine which rates
 491          * were Tx'd based on the total number of retries vs. the number
 492          * of retries configured for each rate -- currently set to the
 493          * priv value 'retry_rate' vs. rate specific
 494          *
 495          * On exit from this while loop last_index indicates the rate
 496          * at which the frame was finally transmitted (or failed if no
 497          * ACK)
 498          */
 499         while (retries > 0) {
 500                 if (retries < priv->retry_rate) {
 501                         current_count = retries;
 502                         last_index = scale_rate_index;
 503                 } else {
 504                         current_count = priv->retry_rate;
 505                         last_index = rs_adjust_next_rate(priv,
 506                                                          scale_rate_index);
 507                 }
 508
 509                 /* Update this rate accounting for as many retries
 510                  * as was used for it (per current_count) */
 511                 iwl3945_collect_tx_data(rs_sta,
 512                                     &rs_sta->win[scale_rate_index],
 513                                     0, current_count);
 514                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 515                                scale_rate_index, current_count);
 516
 517                 retries -= current_count;
 518
 519                 if (retries)
 520                         scale_rate_index =
 521                             rs_adjust_next_rate(priv, scale_rate_index);
 522         }
 523
 524
 525         /* Update the last index window with success/failure based on ACK */
 526         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 527                        last_index,
 528                        (tx_resp->flags & IEEE80211_TX_STATUS_ACK) ?
 529                        "success" : "failure");
 530         iwl3945_collect_tx_data(rs_sta,
 531                             &rs_sta->win[last_index],
 532                             tx_resp->flags & IEEE80211_TX_STATUS_ACK, 1);
 533
 534         /* We updated the rate scale window -- if its been more than
 535          * flush_time since the last run, schedule the flush
 536          * again */
 537         spin_lock_irqsave(&rs_sta->lock, flags);
 538
 539         if (!rs_sta->flush_pending &&
 540             time_after(jiffies, rs_sta->last_partial_flush +
 541                        rs_sta->flush_time)) {
 542
 543                 rs_sta->flush_pending = 1;
 544                 mod_timer(&rs_sta->rate_scale_flush,
 545                           jiffies + rs_sta->flush_time);
 546         }
 547
 548         spin_unlock_irqrestore(&rs_sta->lock, flags);
 549
 550         sta_info_put(sta);
 551
 552         IWL_DEBUG_RATE("leave\n");
 553
 554         return;
 555 }
 556
 557 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 558                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 559 {
 560         u8 high = IWL_RATE_INVALID;
 561         u8 low = IWL_RATE_INVALID;
 562
 563         /* 802.11A walks to the next literal adjacent rate in
 564          * the rate table */
 565         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 566                 int i;
 567                 u32 mask;
 568
 569                 /* Find the previous rate that is in the rate mask */
 570                 i = index - 1;
 571                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 572                         if (rate_mask & mask) {
 573                                 low = i;
 574                                 break;
 575                         }
 576                 }
 577
 578                 /* Find the next rate that is in the rate mask */
 579                 i = index + 1;
 580                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 581                         if (rate_mask & mask) {
 582                                 high = i;
 583                                 break;
 584                         }
 585                 }
 586
 587                 return (high << 8) | low;
 588         }
 589
 590         low = index;
 591         while (low != IWL_RATE_INVALID) {
 592                 if (rs_sta->tgg)
 593                         low = iwl3945_rates[low].prev_rs_tgg;
 594                 else
 595                         low = iwl3945_rates[low].prev_rs;
 596                 if (low == IWL_RATE_INVALID)
 597                         break;
 598                 if (rate_mask & (1 << low))
 599                         break;
 600                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 601         }
 602
 603         high = index;
 604         while (high != IWL_RATE_INVALID) {
 605                 if (rs_sta->tgg)
 606                         high = iwl3945_rates[high].next_rs_tgg;
 607                 else
 608                         high = iwl3945_rates[high].next_rs;
 609                 if (high == IWL_RATE_INVALID)
 610                         break;
 611                 if (rate_mask & (1 << high))
 612                         break;
 613                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 614         }
 615
 616         return (high << 8) | low;
 617 }
 618
 619 /**
 620  * rs_get_rate - find the rate for the requested packet
 621  *
 622  * Returns the ieee80211_rate structure allocated by the driver.
 623  *
 624  * The rate control algorithm has no internal mapping between hw_mode's
 625  * rate ordering and the rate ordering used by the rate control algorithm.
 626  *
 627  * The rate control algorithm uses a single table of rates that goes across
 628  * the entire A/B/G spectrum vs. being limited to just one particular
 629  * hw_mode.
 630  *
 631  * As such, we can't convert the index obtained below into the hw_mode's
 632  * rate table and must reference the driver allocated rate table
 633  *
 634  */
 635 static void rs_get_rate(void *priv_rate, struct net_device *dev,
 636                         struct ieee80211_supported_band *band,
 637                         struct sk_buff *skb,
 638                         struct rate_selection *sel)
 639 {
 640         u8 low = IWL_RATE_INVALID;
 641         u8 high = IWL_RATE_INVALID;
 642         u16 high_low;
 643         int index;
 644         struct iwl3945_rs_sta *rs_sta;
 645         struct iwl3945_rate_scale_data *window = NULL;
 646         int current_tpt = IWL_INVALID_VALUE;
 647         int low_tpt = IWL_INVALID_VALUE;
 648         int high_tpt = IWL_INVALID_VALUE;
 649         u32 fail_count;
 650         s8 scale_action = 0;
 651         unsigned long flags;
 652         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 653         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 654         struct sta_info *sta;
 655         u16 fc, rate_mask;
 656         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 657         DECLARE_MAC_BUF(mac);
 658
 659         IWL_DEBUG_RATE("enter\n");
 660
 661         sta = sta_info_get(local, hdr->addr1);
 662
 663         /* Send management frames and broadcast/multicast data using lowest
 664          * rate. */
 665         fc = le16_to_cpu(hdr->frame_control);
 666         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 667             is_multicast_ether_addr(hdr->addr1) ||
 668             !sta || !sta->rate_ctrl_priv) {
 669                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 670                 sel->rate = rate_lowest(local, band, sta);
 671                 if (sta)
 672                         sta_info_put(sta);
 673                 return;
 674         }
 675
 676         rate_mask = sta->supp_rates[band->band];
 677         index = min(sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 678
 679         if (priv->band == IEEE80211_BAND_5GHZ)
 680                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 681
 682         rs_sta = (void *)sta->rate_ctrl_priv;
 683
 684         if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 685             !rs_sta->ibss_sta_added) {
 686                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 687
 688                 if (sta_id == IWL_INVALID_STATION) {
 689                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 690                                        print_mac(mac, hdr->addr1));
 691                         sta_id = iwl3945_add_station(priv,
 692                                     hdr->addr1, 0, CMD_ASYNC);
 693                 }
 694                 if (sta_id != IWL_INVALID_STATION)
 695                         rs_sta->ibss_sta_added = 1;
 696         }
 697
 698         spin_lock_irqsave(&rs_sta->lock, flags);
 699
 700         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 701                 index = rs_sta->start_rate;
 702                 rs_sta->start_rate = IWL_RATE_INVALID;
 703         }
 704
 705         window = &(rs_sta->win[index]);
 706
 707         fail_count = window->counter - window->success_counter;
 708
 709         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 710              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 711                 window->average_tpt = IWL_INVALID_VALUE;
 712                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 713
 714                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 715                                "counter: %d, success_counter: %d, "
 716                                "expected_tpt is %sNULL\n",
 717                                index,
 718                                window->counter,
 719                                window->success_counter,
 720                                rs_sta->expected_tpt ? "not " : "");
 721                 goto out;
 722
 723         }
 724
 725         window->average_tpt = ((window->success_ratio *
 726                                 rs_sta->expected_tpt[index] + 64) / 128);
 727         current_tpt = window->average_tpt;
 728
 729         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 730                                              band->band);
 731         low = high_low & 0xff;
 732         high = (high_low >> 8) & 0xff;
 733
 734         if (low != IWL_RATE_INVALID)
 735                 low_tpt = rs_sta->win[low].average_tpt;
 736
 737         if (high != IWL_RATE_INVALID)
 738                 high_tpt = rs_sta->win[high].average_tpt;
 739
 740         spin_unlock_irqrestore(&rs_sta->lock, flags);
 741
 742         scale_action = 1;
 743
 744         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 745                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 746                 scale_action = -1;
 747         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 748                    (high_tpt == IWL_INVALID_VALUE))
 749                 scale_action = 1;
 750         else if ((low_tpt != IWL_INVALID_VALUE) &&
 751                    (high_tpt != IWL_INVALID_VALUE)
 752                    && (low_tpt < current_tpt)
 753                    && (high_tpt < current_tpt)) {
 754                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 755                                "current_tpt [%d]\n",
 756                                low_tpt, high_tpt, current_tpt);
 757                 scale_action = 0;
 758         } else {
 759                 if (high_tpt != IWL_INVALID_VALUE) {
 760                         if (high_tpt > current_tpt)
 761                                 scale_action = 1;
 762                         else {
 763                                 IWL_DEBUG_RATE
 764                                     ("decrease rate because of high tpt\n");
 765                                 scale_action = -1;
 766                         }
 767                 } else if (low_tpt != IWL_INVALID_VALUE) {
 768                         if (low_tpt > current_tpt) {
 769                                 IWL_DEBUG_RATE
 770                                     ("decrease rate because of low tpt\n");
 771                                 scale_action = -1;
 772                         } else
 773                                 scale_action = 1;
 774                 }
 775         }
 776
 777         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 778             (current_tpt > window->average_tpt)) {
 779                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 780                                "current_tpt [%d] > average_tpt [%d]\n",
 781                                window->success_ratio,
 782                                current_tpt, window->average_tpt);
 783                 scale_action = 0;
 784         }
 785
 786         switch (scale_action) {
 787         case -1:
 788                 if (low != IWL_RATE_INVALID)
 789                         index = low;
 790                 break;
 791
 792         case 1:
 793                 if (high != IWL_RATE_INVALID)
 794                         index = high;
 795
 796                 break;
 797
 798         case 0:
 799         default:
 800                 break;
 801         }
 802
 803         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 804                        index, scale_action, low, high);
 805
 806  out:
 807
 808         sta->last_txrate_idx = index;
 809         if (priv->band == IEEE80211_BAND_5GHZ)
 810                 sta->txrate_idx = sta->last_txrate_idx - IWL_FIRST_OFDM_RATE;
 811         else
 812                 sta->txrate_idx = sta->last_txrate_idx;
 813
 814         sta_info_put(sta);
 815
 816         IWL_DEBUG_RATE("leave: %d\n", index);
 817
 818         sel->rate = &priv->ieee_rates[index];
 819 }
 820
 821 static struct rate_control_ops rs_ops = {
 822         .module = NULL,
 823         .name = RS_NAME,
 824         .tx_status = rs_tx_status,
 825         .get_rate = rs_get_rate,
 826         .rate_init = rs_rate_init,
 827         .clear = rs_clear,
 828         .alloc = rs_alloc,
 829         .free = rs_free,
 830         .alloc_sta = rs_alloc_sta,
 831         .free_sta = rs_free_sta,
 832 };
 833
 834 int iwl3945_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 835 {
 836         struct ieee80211_local *local = hw_to_local(hw);
 837         struct iwl3945_priv *priv = hw->priv;
 838         struct iwl3945_rs_sta *rs_sta;
 839         struct sta_info *sta;
 840         unsigned long flags;
 841         int count = 0, i;
 842         u32 samples = 0, success = 0, good = 0;
 843         unsigned long now = jiffies;
 844         u32 max_time = 0;
 845
 846         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 847         if (!sta || !sta->rate_ctrl_priv) {
 848                 if (sta) {
 849                         sta_info_put(sta);
 850                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 851                 } else
 852                         IWL_DEBUG_RATE("leave - no station!\n");
 853                 return sprintf(buf, "station %d not found\n", sta_id);
 854         }
 855
 856         rs_sta = (void *)sta->rate_ctrl_priv;
 857         spin_lock_irqsave(&rs_sta->lock, flags);
 858         i = IWL_RATE_54M_INDEX;
 859         while (1) {
 860                 u64 mask;
 861                 int j;
 862
 863                 count +=
 864                     sprintf(&buf[count], " %2dMbs: ", iwl3945_rates[i].ieee / 2);
 865
 866                 mask = (1ULL << (IWL_RATE_MAX_WINDOW - 1));
 867                 for (j = 0; j < IWL_RATE_MAX_WINDOW; j++, mask >>= 1)
 868                         buf[count++] =
 869                             (rs_sta->win[i].data & mask) ? '1' : '0';
 870
 871                 samples += rs_sta->win[i].counter;
 872                 good += rs_sta->win[i].success_counter;
 873                 success += rs_sta->win[i].success_counter *
 874                                                 iwl3945_rates[i].ieee;
 875
 876                 if (rs_sta->win[i].stamp) {
 877                         int delta =
 878                             jiffies_to_msecs(now - rs_sta->win[i].stamp);
 879
 880                         if (delta > max_time)
 881                                 max_time = delta;
 882
 883                         count += sprintf(&buf[count], "%5dms\n", delta);
 884                 } else
 885                         buf[count++] = '\n';
 886
 887                 j = iwl3945_get_prev_ieee_rate(i);
 888                 if (j == i)
 889                         break;
 890                 i = j;
 891         }
 892         spin_unlock_irqrestore(&rs_sta->lock, flags);
 893         sta_info_put(sta);
 894
 895         /* Display the average rate of all samples taken.
 896          *
 897          * NOTE:  We multiple # of samples by 2 since the IEEE measurement
 898          * added from iwl3945_rates is actually 2X the rate */
 899         if (samples)
 900                 count += sprintf(
 901                         &buf[count],
 902                         "\nAverage rate is %3d.%02dMbs over last %4dms\n"
 903                         "%3d%% success (%d good packets over %d tries)\n",
 904                         success / (2 * samples), (success * 5 / samples) % 10,
 905                         max_time, good * 100 / samples, good, samples);
 906         else
 907                 count += sprintf(&buf[count], "\nAverage rate: 0Mbs\n");
 908
 909         return count;
 910 }
 911
 912 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 913 {
 914         struct iwl3945_priv *priv = hw->priv;
 915         s32 rssi = 0;
 916         unsigned long flags;
 917         struct ieee80211_local *local = hw_to_local(hw);
 918         struct iwl3945_rs_sta *rs_sta;
 919         struct sta_info *sta;
 920
 921         IWL_DEBUG_RATE("enter\n");
 922
 923         if (!local->rate_ctrl->ops->name ||
 924             strcmp(local->rate_ctrl->ops->name, RS_NAME)) {
 925                 IWL_WARNING("iwl-3945-rs not selected as rate control algo!\n");
 926                 IWL_DEBUG_RATE("leave - mac80211 picked the wrong RC algo.\n");
 927                 return;
 928         }
 929
 930         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 931         if (!sta || !sta->rate_ctrl_priv) {
 932                 if (sta)
 933                         sta_info_put(sta);
 934                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 935                 return;
 936         }
 937
 938         rs_sta = (void *)sta->rate_ctrl_priv;
 939
 940         spin_lock_irqsave(&rs_sta->lock, flags);
 941
 942         rs_sta->tgg = 0;
 943         switch (priv->band) {
 944         case IEEE80211_BAND_2GHZ:
 945                 /* TODO: this always does G, not a regression */
 946                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 947                         rs_sta->tgg = 1;
 948                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 949                 } else
 950                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 951                 break;
 952
 953         case IEEE80211_BAND_5GHZ:
 954                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 955                 break;
 956         case IEEE80211_NUM_BANDS:
 957                 BUG();
 958                 break;
 959         }
 960
 961         sta_info_put(sta);
 962         spin_unlock_irqrestore(&rs_sta->lock, flags);
 963
 964         rssi = priv->last_rx_rssi;
 965         if (rssi == 0)
 966                 rssi = IWL_MIN_RSSI_VAL;
 967
 968         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 969
 970         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 971
 972         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 973                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 974                        iwl3945_rates[rs_sta->start_rate].plcp);
 975 }
 976
 977 void iwl3945_rate_control_register(struct ieee80211_hw *hw)
 978 {
 979         ieee80211_rate_control_register(&rs_ops);
 980 }
 981
 982 void iwl3945_rate_control_unregister(struct ieee80211_hw *hw)
 983 {
 984         ieee80211_rate_control_unregister(&rs_ops);
 985 }
 986
 987