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  *  Intel Linux Wireless <ilw@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
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/delay.h>
  36
  37 #include <linux/workqueue.h>
  38
  39 #include "iwl-3945.h"
  40
  41 #define RS_NAME "iwl-3945-rs"
  42
  43 struct iwl3945_rate_scale_data {
  44         u64 data;
  45         s32 success_counter;
  46         s32 success_ratio;
  47         s32 counter;
  48         s32 average_tpt;
  49         unsigned long stamp;
  50 };
  51
  52 struct iwl3945_rs_sta {
  53         spinlock_t lock;
  54         s32 *expected_tpt;
  55         unsigned long last_partial_flush;
  56         unsigned long last_flush;
  57         u32 flush_time;
  58         u32 last_tx_packets;
  59         u32 tx_packets;
  60         u8 tgg;
  61         u8 flush_pending;
  62         u8 start_rate;
  63         u8 ibss_sta_added;
  64         struct timer_list rate_scale_flush;
  65         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  66 #ifdef CONFIG_MAC80211_DEBUGFS
  67         struct dentry *rs_sta_dbgfs_stats_table_file;
  68 #endif
  69
  70         /* used to be in sta_info */
  71         int last_txrate_idx;
  72 };
  73
  74 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  75         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  76 };
  77
  78 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  79         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  80 };
  81
  82 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  83         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  84 };
  85
  86 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  87         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  88 };
  89
  90 struct iwl3945_tpt_entry {
  91         s8 min_rssi;
  92         u8 index;
  93 };
  94
  95 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  96         {-60, IWL_RATE_54M_INDEX},
  97         {-64, IWL_RATE_48M_INDEX},
  98         {-72, IWL_RATE_36M_INDEX},
  99         {-80, IWL_RATE_24M_INDEX},
 100         {-84, IWL_RATE_18M_INDEX},
 101         {-85, IWL_RATE_12M_INDEX},
 102         {-87, IWL_RATE_9M_INDEX},
 103         {-89, IWL_RATE_6M_INDEX}
 104 };
 105
 106 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 107         {-60, IWL_RATE_54M_INDEX},
 108         {-64, IWL_RATE_48M_INDEX},
 109         {-68, IWL_RATE_36M_INDEX},
 110         {-80, IWL_RATE_24M_INDEX},
 111         {-84, IWL_RATE_18M_INDEX},
 112         {-85, IWL_RATE_12M_INDEX},
 113         {-86, IWL_RATE_11M_INDEX},
 114         {-88, IWL_RATE_5M_INDEX},
 115         {-90, IWL_RATE_2M_INDEX},
 116         {-92, IWL_RATE_1M_INDEX}
 117 };
 118
 119 #define IWL_RATE_MAX_WINDOW          62
 120 #define IWL_RATE_FLUSH           (3*HZ)
 121 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 122 #define IWL_RATE_HIGH_TH          11520
 123 #define IWL_SUCCESS_UP_TH          8960
 124 #define IWL_SUCCESS_DOWN_TH       10880
 125 #define IWL_RATE_MIN_FAILURE_TH       8
 126 #define IWL_RATE_MIN_SUCCESS_TH       8
 127 #define IWL_RATE_DECREASE_TH       1920
 128
 129 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 130 {
 131         u32 index = 0;
 132         u32 table_size = 0;
 133         struct iwl3945_tpt_entry *tpt_table = NULL;
 134
 135         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 136                 rssi = IWL_MIN_RSSI_VAL;
 137
 138         switch (band) {
 139         case IEEE80211_BAND_2GHZ:
 140                 tpt_table = iwl3945_tpt_table_g;
 141                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 142                 break;
 143
 144         case IEEE80211_BAND_5GHZ:
 145                 tpt_table = iwl3945_tpt_table_a;
 146                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 147                 break;
 148
 149         default:
 150                 BUG();
 151                 break;
 152         }
 153
 154         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 155                 index++;
 156
 157         index = min(index, (table_size - 1));
 158
 159         return tpt_table[index].index;
 160 }
 161
 162 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 163 {
 164         window->data = 0;
 165         window->success_counter = 0;
 166         window->success_ratio = -1;
 167         window->counter = 0;
 168         window->average_tpt = IWL_INV_TPT;
 169         window->stamp = 0;
 170 }
 171
 172 /**
 173  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 174  *
 175  * Returns the number of windows that have gathered data but were
 176  * not flushed.  If there were any that were not flushed, then
 177  * reschedule the rate flushing routine.
 178  */
 179 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 180 {
 181         int unflushed = 0;
 182         int i;
 183         unsigned long flags;
 184
 185         /*
 186          * For each rate, if we have collected data on that rate
 187          * and it has been more than IWL_RATE_WIN_FLUSH
 188          * since we flushed, clear out the gathered statistics
 189          */
 190         for (i = 0; i < IWL_RATE_COUNT; i++) {
 191                 if (!rs_sta->win[i].counter)
 192                         continue;
 193
 194                 spin_lock_irqsave(&rs_sta->lock, flags);
 195                 if (time_after(jiffies, rs_sta->win[i].stamp +
 196                                IWL_RATE_WIN_FLUSH)) {
 197                         IWL_DEBUG_RATE("flushing %d samples of rate "
 198                                        "index %d\n",
 199                                        rs_sta->win[i].counter, i);
 200                         iwl3945_clear_window(&rs_sta->win[i]);
 201                 } else
 202                         unflushed++;
 203                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 204         }
 205
 206         return unflushed;
 207 }
 208
 209 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 210 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 211 #define IWL_AVERAGE_PACKETS             1500
 212
 213 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 214 {
 215         struct iwl3945_rs_sta *rs_sta = (void *)data;
 216         int unflushed = 0;
 217         unsigned long flags;
 218         u32 packet_count, duration, pps;
 219
 220         IWL_DEBUG_RATE("enter\n");
 221
 222         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 223
 224         spin_lock_irqsave(&rs_sta->lock, flags);
 225
 226         /* Number of packets Rx'd since last time this timer ran */
 227         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 228
 229         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 230
 231         if (unflushed) {
 232                 duration =
 233                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 234
 235                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 236                                packet_count, duration);
 237
 238                 /* Determine packets per second */
 239                 if (duration)
 240                         pps = (packet_count * 1000) / duration;
 241                 else
 242                         pps = 0;
 243
 244                 if (pps) {
 245                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 246                         if (duration < IWL_RATE_FLUSH_MIN)
 247                                 duration = IWL_RATE_FLUSH_MIN;
 248                         else if (duration > IWL_RATE_FLUSH_MAX)
 249                                 duration = IWL_RATE_FLUSH_MAX;
 250                 } else
 251                         duration = IWL_RATE_FLUSH_MAX;
 252
 253                 rs_sta->flush_time = msecs_to_jiffies(duration);
 254
 255                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 256                                duration, packet_count);
 257
 258                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 259                           rs_sta->flush_time);
 260
 261                 rs_sta->last_partial_flush = jiffies;
 262         } else {
 263                 rs_sta->flush_time = IWL_RATE_FLUSH;
 264                 rs_sta->flush_pending = 0;
 265         }
 266         /* If there weren't any unflushed entries, we don't schedule the timer
 267          * to run again */
 268
 269         rs_sta->last_flush = jiffies;
 270
 271         spin_unlock_irqrestore(&rs_sta->lock, flags);
 272
 273         IWL_DEBUG_RATE("leave\n");
 274 }
 275
 276 /**
 277  * iwl3945_collect_tx_data - Update the success/failure sliding window
 278  *
 279  * We keep a sliding window of the last 64 packets transmitted
 280  * at this rate.  window->data contains the bitmask of successful
 281  * packets.
 282  */
 283 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 284                                 struct iwl3945_rate_scale_data *window,
 285                                 int success, int retries, int index)
 286 {
 287         unsigned long flags;
 288         s32 fail_count;
 289
 290         if (!retries) {
 291                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 292                 return;
 293         }
 294
 295         spin_lock_irqsave(&rs_sta->lock, flags);
 296         while (retries--) {
 297
 298                 /* If we have filled up the window then subtract one from the
 299                  * success counter if the high-bit is counting toward
 300                  * success */
 301                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 302                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 303                                 window->success_counter--;
 304                 } else
 305                         window->counter++;
 306
 307                 /* Slide the window to the left one bit */
 308                 window->data = (window->data << 1);
 309
 310                 /* If this packet was a success then set the low bit high */
 311                 if (success) {
 312                         window->success_counter++;
 313                         window->data |= 1;
 314                 }
 315
 316                 /* window->counter can't be 0 -- it is either >0 or
 317                  * IWL_RATE_MAX_WINDOW */
 318                 window->success_ratio = 12800 * window->success_counter /
 319                     window->counter;
 320
 321                 /* Tag this window as having been updated */
 322                 window->stamp = jiffies;
 323
 324         }
 325
 326         fail_count = window->counter - window->success_counter;
 327         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 328             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 329                 window->average_tpt = ((window->success_ratio *
 330                                 rs_sta->expected_tpt[index] + 64) / 128);
 331         else
 332                 window->average_tpt = IWL_INV_TPT;
 333
 334         spin_unlock_irqrestore(&rs_sta->lock, flags);
 335
 336 }
 337
 338 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 339                          struct ieee80211_sta *sta, void *priv_sta)
 340 {
 341         struct iwl3945_rs_sta *rs_sta = priv_sta;
 342         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 343         int i;
 344
 345         IWL_DEBUG_RATE("enter\n");
 346
 347         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 348          * the lowest or the highest rate.. Could consider using RSSI from
 349          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 350          * after assoc.. */
 351
 352         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 353                 if (sta->supp_rates[sband->band] & (1 << i)) {
 354                         rs_sta->last_txrate_idx = i;
 355                         break;
 356                 }
 357         }
 358
 359         priv->sta_supp_rates = sta->supp_rates[sband->band];
 360         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 361         if (sband->band == IEEE80211_BAND_5GHZ) {
 362                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 363                 priv->sta_supp_rates = priv->sta_supp_rates <<
 364                                                 IWL_FIRST_OFDM_RATE;
 365         }
 366
 367
 368         IWL_DEBUG_RATE("leave\n");
 369 }
 370
 371 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 372 {
 373         return hw->priv;
 374 }
 375
 376 /* rate scale requires free function to be implemented */
 377 static void rs_free(void *priv)
 378 {
 379         return;
 380 }
 381
 382 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 383 {
 384         struct iwl3945_rs_sta *rs_sta;
 385         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 386         int i;
 387
 388         /*
 389          * XXX: If it's using sta->drv_priv anyway, it might
 390          *      as well just put all the information there.
 391          */
 392
 393         IWL_DEBUG_RATE("enter\n");
 394
 395         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 396         if (!rs_sta) {
 397                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 398                 return NULL;
 399         }
 400
 401         psta->rs_sta = rs_sta;
 402
 403         spin_lock_init(&rs_sta->lock);
 404
 405         rs_sta->start_rate = IWL_RATE_INVALID;
 406
 407         /* default to just 802.11b */
 408         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 409
 410         rs_sta->last_partial_flush = jiffies;
 411         rs_sta->last_flush = jiffies;
 412         rs_sta->flush_time = IWL_RATE_FLUSH;
 413         rs_sta->last_tx_packets = 0;
 414         rs_sta->ibss_sta_added = 0;
 415
 416         init_timer(&rs_sta->rate_scale_flush);
 417         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 418         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 419
 420         for (i = 0; i < IWL_RATE_COUNT; i++)
 421                 iwl3945_clear_window(&rs_sta->win[i]);
 422
 423         IWL_DEBUG_RATE("leave\n");
 424
 425         return rs_sta;
 426 }
 427
 428 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 429                         void *priv_sta)
 430 {
 431         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 432         struct iwl3945_rs_sta *rs_sta = priv_sta;
 433
 434         psta->rs_sta = NULL;
 435
 436         IWL_DEBUG_RATE("enter\n");
 437         del_timer_sync(&rs_sta->rate_scale_flush);
 438         kfree(rs_sta);
 439         IWL_DEBUG_RATE("leave\n");
 440 }
 441
 442
 443 /**
 444  * rs_tx_status - Update rate control values based on Tx results
 445  *
 446  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 447  * the hardware for each rate.
 448  */
 449 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 450                          struct ieee80211_sta *sta, void *priv_sta,
 451                          struct sk_buff *skb)
 452 {
 453         s8 retries = 0, current_count;
 454         int scale_rate_index, first_index, last_index;
 455         unsigned long flags;
 456         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 457         struct iwl3945_rs_sta *rs_sta = priv_sta;
 458         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 459
 460         IWL_DEBUG_RATE("enter\n");
 461
 462         retries = info->status.rates[0].count;
 463
 464         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 465         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 466                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 467                 return;
 468         }
 469
 470         if (!priv_sta) {
 471                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 472                 return;
 473         }
 474
 475         rs_sta->tx_packets++;
 476
 477         scale_rate_index = first_index;
 478         last_index = first_index;
 479
 480         /*
 481          * Update the window for each rate.  We determine which rates
 482          * were Tx'd based on the total number of retries vs. the number
 483          * of retries configured for each rate -- currently set to the
 484          * priv value 'retry_rate' vs. rate specific
 485          *
 486          * On exit from this while loop last_index indicates the rate
 487          * at which the frame was finally transmitted (or failed if no
 488          * ACK)
 489          */
 490         while (retries > 1) {
 491                 if ((retries - 1) < priv->retry_rate) {
 492                         current_count = (retries - 1);
 493                         last_index = scale_rate_index;
 494                 } else {
 495                         current_count = priv->retry_rate;
 496                         last_index = iwl3945_rs_next_rate(priv,
 497                                                          scale_rate_index);
 498                 }
 499
 500                 /* Update this rate accounting for as many retries
 501                  * as was used for it (per current_count) */
 502                 iwl3945_collect_tx_data(rs_sta,
 503                                     &rs_sta->win[scale_rate_index],
 504                                     0, current_count, scale_rate_index);
 505                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 506                                scale_rate_index, current_count);
 507
 508                 retries -= current_count;
 509
 510                 scale_rate_index = last_index;
 511         }
 512
 513
 514         /* Update the last index window with success/failure based on ACK */
 515         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 516                        last_index,
 517                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 518                        "success" : "failure");
 519         iwl3945_collect_tx_data(rs_sta,
 520                             &rs_sta->win[last_index],
 521                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 522
 523         /* We updated the rate scale window -- if its been more than
 524          * flush_time since the last run, schedule the flush
 525          * again */
 526         spin_lock_irqsave(&rs_sta->lock, flags);
 527
 528         if (!rs_sta->flush_pending &&
 529             time_after(jiffies, rs_sta->last_flush +
 530                        rs_sta->flush_time)) {
 531
 532                 rs_sta->last_partial_flush = jiffies;
 533                 rs_sta->flush_pending = 1;
 534                 mod_timer(&rs_sta->rate_scale_flush,
 535                           jiffies + rs_sta->flush_time);
 536         }
 537
 538         spin_unlock_irqrestore(&rs_sta->lock, flags);
 539
 540         IWL_DEBUG_RATE("leave\n");
 541
 542         return;
 543 }
 544
 545 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 546                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 547 {
 548         u8 high = IWL_RATE_INVALID;
 549         u8 low = IWL_RATE_INVALID;
 550
 551         /* 802.11A walks to the next literal adjacent rate in
 552          * the rate table */
 553         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 554                 int i;
 555                 u32 mask;
 556
 557                 /* Find the previous rate that is in the rate mask */
 558                 i = index - 1;
 559                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 560                         if (rate_mask & mask) {
 561                                 low = i;
 562                                 break;
 563                         }
 564                 }
 565
 566                 /* Find the next rate that is in the rate mask */
 567                 i = index + 1;
 568                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 569                         if (rate_mask & mask) {
 570                                 high = i;
 571                                 break;
 572                         }
 573                 }
 574
 575                 return (high << 8) | low;
 576         }
 577
 578         low = index;
 579         while (low != IWL_RATE_INVALID) {
 580                 if (rs_sta->tgg)
 581                         low = iwl3945_rates[low].prev_rs_tgg;
 582                 else
 583                         low = iwl3945_rates[low].prev_rs;
 584                 if (low == IWL_RATE_INVALID)
 585                         break;
 586                 if (rate_mask & (1 << low))
 587                         break;
 588                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 589         }
 590
 591         high = index;
 592         while (high != IWL_RATE_INVALID) {
 593                 if (rs_sta->tgg)
 594                         high = iwl3945_rates[high].next_rs_tgg;
 595                 else
 596                         high = iwl3945_rates[high].next_rs;
 597                 if (high == IWL_RATE_INVALID)
 598                         break;
 599                 if (rate_mask & (1 << high))
 600                         break;
 601                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 602         }
 603
 604         return (high << 8) | low;
 605 }
 606
 607 /**
 608  * rs_get_rate - find the rate for the requested packet
 609  *
 610  * Returns the ieee80211_rate structure allocated by the driver.
 611  *
 612  * The rate control algorithm has no internal mapping between hw_mode's
 613  * rate ordering and the rate ordering used by the rate control algorithm.
 614  *
 615  * The rate control algorithm uses a single table of rates that goes across
 616  * the entire A/B/G spectrum vs. being limited to just one particular
 617  * hw_mode.
 618  *
 619  * As such, we can't convert the index obtained below into the hw_mode's
 620  * rate table and must reference the driver allocated rate table
 621  *
 622  */
 623 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 624                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 625 {
 626         struct ieee80211_supported_band *sband = txrc->sband;
 627         struct sk_buff *skb = txrc->skb;
 628         u8 low = IWL_RATE_INVALID;
 629         u8 high = IWL_RATE_INVALID;
 630         u16 high_low;
 631         int index;
 632         struct iwl3945_rs_sta *rs_sta = priv_sta;
 633         struct iwl3945_rate_scale_data *window = NULL;
 634         int current_tpt = IWL_INV_TPT;
 635         int low_tpt = IWL_INV_TPT;
 636         int high_tpt = IWL_INV_TPT;
 637         u32 fail_count;
 638         s8 scale_action = 0;
 639         unsigned long flags;
 640         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 641         u16 fc, rate_mask;
 642         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 643         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 644
 645         IWL_DEBUG_RATE("enter\n");
 646
 647         /* Send management frames and broadcast/multicast data using lowest
 648          * rate. */
 649         fc = le16_to_cpu(hdr->frame_control);
 650         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 651             is_multicast_ether_addr(hdr->addr1) ||
 652             !sta || !priv_sta) {
 653                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 654                 info->control.rates[0].idx = rate_lowest_index(sband, sta);
 655                 return;
 656         }
 657
 658         rate_mask = sta->supp_rates[sband->band];
 659         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 660
 661         if (sband->band == IEEE80211_BAND_5GHZ)
 662                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 663
 664         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 665             !rs_sta->ibss_sta_added) {
 666                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 667
 668                 if (sta_id == IWL_INVALID_STATION) {
 669                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 670                                        hdr->addr1);
 671                         sta_id = iwl3945_add_station(priv,
 672                                     hdr->addr1, 0, CMD_ASYNC);
 673                 }
 674                 if (sta_id != IWL_INVALID_STATION)
 675                         rs_sta->ibss_sta_added = 1;
 676         }
 677
 678         spin_lock_irqsave(&rs_sta->lock, flags);
 679
 680         /* for recent assoc, choose best rate regarding
 681          * to rssi value
 682          */
 683         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 684                 if (rs_sta->start_rate < index &&
 685                    (rate_mask & (1 << rs_sta->start_rate)))
 686                         index = rs_sta->start_rate;
 687                 rs_sta->start_rate = IWL_RATE_INVALID;
 688         }
 689
 690         window = &(rs_sta->win[index]);
 691
 692         fail_count = window->counter - window->success_counter;
 693
 694         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 695              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 696                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 697
 698                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 699                                "counter: %d, success_counter: %d, "
 700                                "expected_tpt is %sNULL\n",
 701                                index,
 702                                window->counter,
 703                                window->success_counter,
 704                                rs_sta->expected_tpt ? "not " : "");
 705                 goto out;
 706
 707         }
 708
 709         current_tpt = window->average_tpt;
 710
 711         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 712                                              sband->band);
 713         low = high_low & 0xff;
 714         high = (high_low >> 8) & 0xff;
 715
 716         if (low != IWL_RATE_INVALID)
 717                 low_tpt = rs_sta->win[low].average_tpt;
 718
 719         if (high != IWL_RATE_INVALID)
 720                 high_tpt = rs_sta->win[high].average_tpt;
 721
 722         spin_unlock_irqrestore(&rs_sta->lock, flags);
 723
 724         scale_action = 1;
 725
 726         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 727                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 728                 scale_action = -1;
 729         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 730                 scale_action = 1;
 731         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 732                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 733                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 734                                "current_tpt [%d]\n",
 735                                low_tpt, high_tpt, current_tpt);
 736                 scale_action = 0;
 737         } else {
 738                 if (high_tpt != IWL_INV_TPT) {
 739                         if (high_tpt > current_tpt)
 740                                 scale_action = 1;
 741                         else {
 742                                 IWL_DEBUG_RATE
 743                                     ("decrease rate because of high tpt\n");
 744                                 scale_action = -1;
 745                         }
 746                 } else if (low_tpt != IWL_INV_TPT) {
 747                         if (low_tpt > current_tpt) {
 748                                 IWL_DEBUG_RATE
 749                                     ("decrease rate because of low tpt\n");
 750                                 scale_action = -1;
 751                         } else
 752                                 scale_action = 1;
 753                 }
 754         }
 755
 756         if (scale_action == -1) {
 757                 if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
 758                         scale_action = 0;
 759         } else if (scale_action == 1) {
 760                 if (window->success_ratio < IWL_SUCCESS_UP_TH) {
 761                         IWL_DEBUG_RATE("No action -- success_ratio [%d] < "
 762                                "SUCCESS UP\n", window->success_ratio);
 763                         scale_action = 0;
 764                 }
 765         }
 766
 767         switch (scale_action) {
 768         case -1:
 769                 if (low != IWL_RATE_INVALID)
 770                         index = low;
 771                 break;
 772
 773         case 1:
 774                 if (high != IWL_RATE_INVALID)
 775                         index = high;
 776
 777                 break;
 778
 779         case 0:
 780         default:
 781                 break;
 782         }
 783
 784         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 785                        index, scale_action, low, high);
 786
 787  out:
 788
 789         rs_sta->last_txrate_idx = index;
 790         if (sband->band == IEEE80211_BAND_5GHZ)
 791                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 792                                 IWL_FIRST_OFDM_RATE;
 793         else
 794                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 795
 796         IWL_DEBUG_RATE("leave: %d\n", index);
 797 }
 798
 799 #ifdef CONFIG_MAC80211_DEBUGFS
 800 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 801 {
 802         file->private_data = inode->i_private;
 803         return 0;
 804 }
 805
 806 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 807                                                   char __user *user_buf,
 808                                                   size_t count, loff_t *ppos)
 809 {
 810         char buff[1024];
 811         int desc = 0;
 812         int j;
 813         struct iwl3945_rs_sta *lq_sta = file->private_data;
 814
 815         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 816                         "rate=0x%X flush time %d\n",
 817                         lq_sta->tx_packets,
 818                         lq_sta->last_txrate_idx,
 819                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 820         for (j = 0; j < IWL_RATE_COUNT; j++) {
 821                 desc += sprintf(buff+desc,
 822                                 "counter=%d success=%d %%=%d\n",
 823                                 lq_sta->win[j].counter,
 824                                 lq_sta->win[j].success_counter,
 825                                 lq_sta->win[j].success_ratio);
 826         }
 827         return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 828 }
 829
 830 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 831         .read = iwl3945_sta_dbgfs_stats_table_read,
 832         .open = iwl3945_open_file_generic,
 833 };
 834
 835 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 836                                 struct dentry *dir)
 837 {
 838         struct iwl3945_rs_sta *lq_sta = priv_sta;
 839
 840         lq_sta->rs_sta_dbgfs_stats_table_file =
 841                 debugfs_create_file("rate_stats_table", 0600, dir,
 842                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 843
 844 }
 845
 846 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 847 {
 848         struct iwl3945_rs_sta *lq_sta = priv_sta;
 849         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 850 }
 851 #endif
 852
 853 static struct rate_control_ops rs_ops = {
 854         .module = NULL,
 855         .name = RS_NAME,
 856         .tx_status = rs_tx_status,
 857         .get_rate = rs_get_rate,
 858         .rate_init = rs_rate_init,
 859         .alloc = rs_alloc,
 860         .free = rs_free,
 861         .alloc_sta = rs_alloc_sta,
 862         .free_sta = rs_free_sta,
 863 #ifdef CONFIG_MAC80211_DEBUGFS
 864         .add_sta_debugfs = iwl3945_add_debugfs,
 865         .remove_sta_debugfs = iwl3945_remove_debugfs,
 866 #endif
 867
 868 };
 869
 870 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 871 {
 872         struct iwl3945_priv *priv = hw->priv;
 873         s32 rssi = 0;
 874         unsigned long flags;
 875         struct iwl3945_rs_sta *rs_sta;
 876         struct ieee80211_sta *sta;
 877         struct iwl3945_sta_priv *psta;
 878
 879         IWL_DEBUG_RATE("enter\n");
 880
 881         rcu_read_lock();
 882
 883         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 884         if (!sta) {
 885                 rcu_read_unlock();
 886                 return;
 887         }
 888
 889         psta = (void *) sta->drv_priv;
 890         rs_sta = psta->rs_sta;
 891
 892         spin_lock_irqsave(&rs_sta->lock, flags);
 893
 894         rs_sta->tgg = 0;
 895         switch (priv->band) {
 896         case IEEE80211_BAND_2GHZ:
 897                 /* TODO: this always does G, not a regression */
 898                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 899                         rs_sta->tgg = 1;
 900                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 901                 } else
 902                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 903                 break;
 904
 905         case IEEE80211_BAND_5GHZ:
 906                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 907                 break;
 908         case IEEE80211_NUM_BANDS:
 909                 BUG();
 910                 break;
 911         }
 912
 913         spin_unlock_irqrestore(&rs_sta->lock, flags);
 914
 915         rssi = priv->last_rx_rssi;
 916         if (rssi == 0)
 917                 rssi = IWL_MIN_RSSI_VAL;
 918
 919         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 920
 921         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 922
 923         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 924                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 925                        iwl3945_rates[rs_sta->start_rate].plcp);
 926         rcu_read_unlock();
 927 }
 928
 929 int iwl3945_rate_control_register(void)
 930 {
 931         return ieee80211_rate_control_register(&rs_ops);
 932 }
 933
 934 void iwl3945_rate_control_unregister(void)
 935 {
 936         ieee80211_rate_control_unregister(&rs_ops);
 937 }
 938
 939