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

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2008 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/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 = -1;
 162         window->counter = 0;
 163         window->average_tpt = IWL_INV_TPT;
 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         IWL_DEBUG_RATE("enter\n");
 463
 464         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 465
 466
 467         retries = tx_resp->retry_count;
 468         first_index = tx_resp->control.tx_rate->hw_value;
 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         rcu_read_lock();
 475
 476         sta = sta_info_get(local, hdr->addr1);
 477         if (!sta || !sta->rate_ctrl_priv) {
 478                 rcu_read_unlock();
 479                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 480                 return;
 481         }
 482
 483         rs_sta = (void *)sta->rate_ctrl_priv;
 484
 485         rs_sta->tx_packets++;
 486
 487         scale_rate_index = first_index;
 488         last_index = first_index;
 489
 490         /*
 491          * Update the window for each rate.  We determine which rates
 492          * were Tx'd based on the total number of retries vs. the number
 493          * of retries configured for each rate -- currently set to the
 494          * priv value 'retry_rate' vs. rate specific
 495          *
 496          * On exit from this while loop last_index indicates the rate
 497          * at which the frame was finally transmitted (or failed if no
 498          * ACK)
 499          */
 500         while (retries > 0) {
 501                 if (retries < priv->retry_rate) {
 502                         current_count = retries;
 503                         last_index = scale_rate_index;
 504                 } else {
 505                         current_count = priv->retry_rate;
 506                         last_index = rs_adjust_next_rate(priv,
 507                                                          scale_rate_index);
 508                 }
 509
 510                 /* Update this rate accounting for as many retries
 511                  * as was used for it (per current_count) */
 512                 iwl3945_collect_tx_data(rs_sta,
 513                                     &rs_sta->win[scale_rate_index],
 514                                     0, current_count);
 515                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 516                                scale_rate_index, current_count);
 517
 518                 retries -= current_count;
 519
 520                 if (retries)
 521                         scale_rate_index =
 522                             rs_adjust_next_rate(priv, scale_rate_index);
 523         }
 524
 525
 526         /* Update the last index window with success/failure based on ACK */
 527         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 528                        last_index,
 529                        (tx_resp->flags & IEEE80211_TX_STATUS_ACK) ?
 530                        "success" : "failure");
 531         iwl3945_collect_tx_data(rs_sta,
 532                             &rs_sta->win[last_index],
 533                             tx_resp->flags & IEEE80211_TX_STATUS_ACK, 1);
 534
 535         /* We updated the rate scale window -- if its been more than
 536          * flush_time since the last run, schedule the flush
 537          * again */
 538         spin_lock_irqsave(&rs_sta->lock, flags);
 539
 540         if (!rs_sta->flush_pending &&
 541             time_after(jiffies, rs_sta->last_partial_flush +
 542                        rs_sta->flush_time)) {
 543
 544                 rs_sta->flush_pending = 1;
 545                 mod_timer(&rs_sta->rate_scale_flush,
 546                           jiffies + rs_sta->flush_time);
 547         }
 548
 549         spin_unlock_irqrestore(&rs_sta->lock, flags);
 550
 551         rcu_read_unlock();
 552
 553         IWL_DEBUG_RATE("leave\n");
 554
 555         return;
 556 }
 557
 558 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 559                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 560 {
 561         u8 high = IWL_RATE_INVALID;
 562         u8 low = IWL_RATE_INVALID;
 563
 564         /* 802.11A walks to the next literal adjacent rate in
 565          * the rate table */
 566         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 567                 int i;
 568                 u32 mask;
 569
 570                 /* Find the previous rate that is in the rate mask */
 571                 i = index - 1;
 572                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 573                         if (rate_mask & mask) {
 574                                 low = i;
 575                                 break;
 576                         }
 577                 }
 578
 579                 /* Find the next rate that is in the rate mask */
 580                 i = index + 1;
 581                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 582                         if (rate_mask & mask) {
 583                                 high = i;
 584                                 break;
 585                         }
 586                 }
 587
 588                 return (high << 8) | low;
 589         }
 590
 591         low = index;
 592         while (low != IWL_RATE_INVALID) {
 593                 if (rs_sta->tgg)
 594                         low = iwl3945_rates[low].prev_rs_tgg;
 595                 else
 596                         low = iwl3945_rates[low].prev_rs;
 597                 if (low == IWL_RATE_INVALID)
 598                         break;
 599                 if (rate_mask & (1 << low))
 600                         break;
 601                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 602         }
 603
 604         high = index;
 605         while (high != IWL_RATE_INVALID) {
 606                 if (rs_sta->tgg)
 607                         high = iwl3945_rates[high].next_rs_tgg;
 608                 else
 609                         high = iwl3945_rates[high].next_rs;
 610                 if (high == IWL_RATE_INVALID)
 611                         break;
 612                 if (rate_mask & (1 << high))
 613                         break;
 614                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 615         }
 616
 617         return (high << 8) | low;
 618 }
 619
 620 /**
 621  * rs_get_rate - find the rate for the requested packet
 622  *
 623  * Returns the ieee80211_rate structure allocated by the driver.
 624  *
 625  * The rate control algorithm has no internal mapping between hw_mode's
 626  * rate ordering and the rate ordering used by the rate control algorithm.
 627  *
 628  * The rate control algorithm uses a single table of rates that goes across
 629  * the entire A/B/G spectrum vs. being limited to just one particular
 630  * hw_mode.
 631  *
 632  * As such, we can't convert the index obtained below into the hw_mode's
 633  * rate table and must reference the driver allocated rate table
 634  *
 635  */
 636 static void rs_get_rate(void *priv_rate, struct net_device *dev,
 637                         struct ieee80211_supported_band *sband,
 638                         struct sk_buff *skb,
 639                         struct rate_selection *sel)
 640 {
 641         u8 low = IWL_RATE_INVALID;
 642         u8 high = IWL_RATE_INVALID;
 643         u16 high_low;
 644         int index;
 645         struct iwl3945_rs_sta *rs_sta;
 646         struct iwl3945_rate_scale_data *window = NULL;
 647         int current_tpt = IWL_INV_TPT;
 648         int low_tpt = IWL_INV_TPT;
 649         int high_tpt = IWL_INV_TPT;
 650         u32 fail_count;
 651         s8 scale_action = 0;
 652         unsigned long flags;
 653         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 654         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 655         struct sta_info *sta;
 656         u16 fc, rate_mask;
 657         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 658         DECLARE_MAC_BUF(mac);
 659
 660         IWL_DEBUG_RATE("enter\n");
 661
 662         rcu_read_lock();
 663
 664         sta = sta_info_get(local, hdr->addr1);
 665
 666         /* Send management frames and broadcast/multicast data using lowest
 667          * rate. */
 668         fc = le16_to_cpu(hdr->frame_control);
 669         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 670             is_multicast_ether_addr(hdr->addr1) ||
 671             !sta || !sta->rate_ctrl_priv) {
 672                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 673                 sel->rate = rate_lowest(local, sband, sta);
 674                 rcu_read_unlock();
 675                 return;
 676         }
 677
 678         rate_mask = sta->supp_rates[sband->band];
 679         index = min(sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 680
 681         if (sband->band == IEEE80211_BAND_5GHZ)
 682                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 683
 684         rs_sta = (void *)sta->rate_ctrl_priv;
 685
 686         if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 687             !rs_sta->ibss_sta_added) {
 688                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 689
 690                 if (sta_id == IWL_INVALID_STATION) {
 691                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 692                                        print_mac(mac, hdr->addr1));
 693                         sta_id = iwl3945_add_station(priv,
 694                                     hdr->addr1, 0, CMD_ASYNC);
 695                 }
 696                 if (sta_id != IWL_INVALID_STATION)
 697                         rs_sta->ibss_sta_added = 1;
 698         }
 699
 700         spin_lock_irqsave(&rs_sta->lock, flags);
 701
 702         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 703                 index = rs_sta->start_rate;
 704                 rs_sta->start_rate = IWL_RATE_INVALID;
 705         }
 706
 707         window = &(rs_sta->win[index]);
 708
 709         fail_count = window->counter - window->success_counter;
 710
 711         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 712              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 713                 window->average_tpt = IWL_INV_TPT;
 714                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 715
 716                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 717                                "counter: %d, success_counter: %d, "
 718                                "expected_tpt is %sNULL\n",
 719                                index,
 720                                window->counter,
 721                                window->success_counter,
 722                                rs_sta->expected_tpt ? "not " : "");
 723                 goto out;
 724
 725         }
 726
 727         window->average_tpt = ((window->success_ratio *
 728                                 rs_sta->expected_tpt[index] + 64) / 128);
 729         current_tpt = window->average_tpt;
 730
 731         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 732                                              sband->band);
 733         low = high_low & 0xff;
 734         high = (high_low >> 8) & 0xff;
 735
 736         if (low != IWL_RATE_INVALID)
 737                 low_tpt = rs_sta->win[low].average_tpt;
 738
 739         if (high != IWL_RATE_INVALID)
 740                 high_tpt = rs_sta->win[high].average_tpt;
 741
 742         spin_unlock_irqrestore(&rs_sta->lock, flags);
 743
 744         scale_action = 1;
 745
 746         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 747                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 748                 scale_action = -1;
 749         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 750                 scale_action = 1;
 751         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 752                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 753                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 754                                "current_tpt [%d]\n",
 755                                low_tpt, high_tpt, current_tpt);
 756                 scale_action = 0;
 757         } else {
 758                 if (high_tpt != IWL_INV_TPT) {
 759                         if (high_tpt > current_tpt)
 760                                 scale_action = 1;
 761                         else {
 762                                 IWL_DEBUG_RATE
 763                                     ("decrease rate because of high tpt\n");
 764                                 scale_action = -1;
 765                         }
 766                 } else if (low_tpt != IWL_INV_TPT) {
 767                         if (low_tpt > current_tpt) {
 768                                 IWL_DEBUG_RATE
 769                                     ("decrease rate because of low tpt\n");
 770                                 scale_action = -1;
 771                         } else
 772                                 scale_action = 1;
 773                 }
 774         }
 775
 776         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 777             (current_tpt > window->average_tpt)) {
 778                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 779                                "current_tpt [%d] > average_tpt [%d]\n",
 780                                window->success_ratio,
 781                                current_tpt, window->average_tpt);
 782                 scale_action = 0;
 783         }
 784
 785         switch (scale_action) {
 786         case -1:
 787                 if (low != IWL_RATE_INVALID)
 788                         index = low;
 789                 break;
 790
 791         case 1:
 792                 if (high != IWL_RATE_INVALID)
 793                         index = high;
 794
 795                 break;
 796
 797         case 0:
 798         default:
 799                 break;
 800         }
 801
 802         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 803                        index, scale_action, low, high);
 804
 805  out:
 806
 807         sta->last_txrate_idx = index;
 808         if (sband->band == IEEE80211_BAND_5GHZ)
 809                 sta->txrate_idx = sta->last_txrate_idx - IWL_FIRST_OFDM_RATE;
 810         else
 811                 sta->txrate_idx = sta->last_txrate_idx;
 812
 813         rcu_read_unlock();
 814
 815         IWL_DEBUG_RATE("leave: %d\n", index);
 816
 817         sel->rate = &sband->bitrates[sta->txrate_idx];
 818 }
 819
 820 static struct rate_control_ops rs_ops = {
 821         .module = NULL,
 822         .name = RS_NAME,
 823         .tx_status = rs_tx_status,
 824         .get_rate = rs_get_rate,
 825         .rate_init = rs_rate_init,
 826         .clear = rs_clear,
 827         .alloc = rs_alloc,
 828         .free = rs_free,
 829         .alloc_sta = rs_alloc_sta,
 830         .free_sta = rs_free_sta,
 831 };
 832
 833 int iwl3945_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 834 {
 835         struct ieee80211_local *local = hw_to_local(hw);
 836         struct iwl3945_priv *priv = hw->priv;
 837         struct iwl3945_rs_sta *rs_sta;
 838         struct sta_info *sta;
 839         unsigned long flags;
 840         int count = 0, i;
 841         u32 samples = 0, success = 0, good = 0;
 842         unsigned long now = jiffies;
 843         u32 max_time = 0;
 844
 845         rcu_read_lock();
 846
 847         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 848         if (!sta || !sta->rate_ctrl_priv) {
 849                 if (sta)
 850                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 851                 else
 852                         IWL_DEBUG_RATE("leave - no station!\n");
 853                 rcu_read_unlock();
 854                 return sprintf(buf, "station %d not found\n", sta_id);
 855         }
 856
 857         rs_sta = (void *)sta->rate_ctrl_priv;
 858         spin_lock_irqsave(&rs_sta->lock, flags);
 859         i = IWL_RATE_54M_INDEX;
 860         while (1) {
 861                 u64 mask;
 862                 int j;
 863
 864                 count +=
 865                     sprintf(&buf[count], " %2dMbs: ", iwl3945_rates[i].ieee / 2);
 866
 867                 mask = (1ULL << (IWL_RATE_MAX_WINDOW - 1));
 868                 for (j = 0; j < IWL_RATE_MAX_WINDOW; j++, mask >>= 1)
 869                         buf[count++] =
 870                             (rs_sta->win[i].data & mask) ? '1' : '0';
 871
 872                 samples += rs_sta->win[i].counter;
 873                 good += rs_sta->win[i].success_counter;
 874                 success += rs_sta->win[i].success_counter *
 875                                                 iwl3945_rates[i].ieee;
 876
 877                 if (rs_sta->win[i].stamp) {
 878                         int delta =
 879                             jiffies_to_msecs(now - rs_sta->win[i].stamp);
 880
 881                         if (delta > max_time)
 882                                 max_time = delta;
 883
 884                         count += sprintf(&buf[count], "%5dms\n", delta);
 885                 } else
 886                         buf[count++] = '\n';
 887
 888                 j = iwl3945_get_prev_ieee_rate(i);
 889                 if (j == i)
 890                         break;
 891                 i = j;
 892         }
 893         spin_unlock_irqrestore(&rs_sta->lock, flags);
 894         rcu_read_unlock();
 895
 896         /* Display the average rate of all samples taken.
 897          *
 898          * NOTE:  We multiple # of samples by 2 since the IEEE measurement
 899          * added from iwl3945_rates is actually 2X the rate */
 900         if (samples)
 901                 count += sprintf(
 902                         &buf[count],
 903                         "\nAverage rate is %3d.%02dMbs over last %4dms\n"
 904                         "%3d%% success (%d good packets over %d tries)\n",
 905                         success / (2 * samples), (success * 5 / samples) % 10,
 906                         max_time, good * 100 / samples, good, samples);
 907         else
 908                 count += sprintf(&buf[count], "\nAverage rate: 0Mbs\n");
 909
 910         return count;
 911 }
 912
 913 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 914 {
 915         struct iwl3945_priv *priv = hw->priv;
 916         s32 rssi = 0;
 917         unsigned long flags;
 918         struct ieee80211_local *local = hw_to_local(hw);
 919         struct iwl3945_rs_sta *rs_sta;
 920         struct sta_info *sta;
 921
 922         IWL_DEBUG_RATE("enter\n");
 923
 924         if (!local->rate_ctrl->ops->name ||
 925             strcmp(local->rate_ctrl->ops->name, RS_NAME)) {
 926                 IWL_WARNING("iwl-3945-rs not selected as rate control algo!\n");
 927                 IWL_DEBUG_RATE("leave - mac80211 picked the wrong RC algo.\n");
 928                 return;
 929         }
 930
 931         rcu_read_lock();
 932
 933         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 934         if (!sta || !sta->rate_ctrl_priv) {
 935                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 936                 rcu_read_unlock();
 937                 return;
 938         }
 939
 940         rs_sta = (void *)sta->rate_ctrl_priv;
 941
 942         spin_lock_irqsave(&rs_sta->lock, flags);
 943
 944         rs_sta->tgg = 0;
 945         switch (priv->band) {
 946         case IEEE80211_BAND_2GHZ:
 947                 /* TODO: this always does G, not a regression */
 948                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 949                         rs_sta->tgg = 1;
 950                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 951                 } else
 952                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 953                 break;
 954
 955         case IEEE80211_BAND_5GHZ:
 956                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 957                 break;
 958         case IEEE80211_NUM_BANDS:
 959                 BUG();
 960                 break;
 961         }
 962
 963         rcu_read_unlock();
 964         spin_unlock_irqrestore(&rs_sta->lock, flags);
 965
 966         rssi = priv->last_rx_rssi;
 967         if (rssi == 0)
 968                 rssi = IWL_MIN_RSSI_VAL;
 969
 970         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 971
 972         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 973
 974         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 975                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 976                        iwl3945_rates[rs_sta->start_rate].plcp);
 977 }
 978
 979 int iwl3945_rate_control_register(void)
 980 {
 981         return ieee80211_rate_control_register(&rs_ops);
 982 }
 983
 984 void iwl3945_rate_control_unregister(void)
 985 {
 986         ieee80211_rate_control_unregister(&rs_ops);
 987 }
 988
 989