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
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/delay.h>
  36
  37 #include <linux/workqueue.h>
  38
  39 #include "../net/mac80211/rate.h"
  40
  41 #include "iwl-3945.h"
  42
  43 #define RS_NAME "iwl-3945-rs"
  44
  45 struct iwl3945_rate_scale_data {
  46         u64 data;
  47         s32 success_counter;
  48         s32 success_ratio;
  49         s32 counter;
  50         s32 average_tpt;
  51         unsigned long stamp;
  52 };
  53
  54 struct iwl3945_rs_sta {
  55         spinlock_t lock;
  56         s32 *expected_tpt;
  57         unsigned long last_partial_flush;
  58         unsigned long last_flush;
  59         u32 flush_time;
  60         u32 last_tx_packets;
  61         u32 tx_packets;
  62         u8 tgg;
  63         u8 flush_pending;
  64         u8 start_rate;
  65         u8 ibss_sta_added;
  66         struct timer_list rate_scale_flush;
  67         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  68 };
  69
  70 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  71         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  72 };
  73
  74 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  75         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  76 };
  77
  78 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  79         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  80 };
  81
  82 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  83         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  84 };
  85
  86 struct iwl3945_tpt_entry {
  87         s8 min_rssi;
  88         u8 index;
  89 };
  90
  91 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  92         {-60, IWL_RATE_54M_INDEX},
  93         {-64, IWL_RATE_48M_INDEX},
  94         {-72, IWL_RATE_36M_INDEX},
  95         {-80, IWL_RATE_24M_INDEX},
  96         {-84, IWL_RATE_18M_INDEX},
  97         {-85, IWL_RATE_12M_INDEX},
  98         {-87, IWL_RATE_9M_INDEX},
  99         {-89, IWL_RATE_6M_INDEX}
 100 };
 101
 102 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 103         {-60, IWL_RATE_54M_INDEX},
 104         {-64, IWL_RATE_48M_INDEX},
 105         {-68, IWL_RATE_36M_INDEX},
 106         {-80, IWL_RATE_24M_INDEX},
 107         {-84, IWL_RATE_18M_INDEX},
 108         {-85, IWL_RATE_12M_INDEX},
 109         {-86, IWL_RATE_11M_INDEX},
 110         {-88, IWL_RATE_5M_INDEX},
 111         {-90, IWL_RATE_2M_INDEX},
 112         {-92, IWL_RATE_1M_INDEX}
 113 };
 114
 115 #define IWL_RATE_MAX_WINDOW          62
 116 #define IWL_RATE_FLUSH        (3*HZ/10)
 117 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 118 #define IWL_RATE_HIGH_TH          11520
 119 #define IWL_RATE_MIN_FAILURE_TH       8
 120 #define IWL_RATE_MIN_SUCCESS_TH       8
 121 #define IWL_RATE_DECREASE_TH       1920
 122
 123 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 124 {
 125         u32 index = 0;
 126         u32 table_size = 0;
 127         struct iwl3945_tpt_entry *tpt_table = NULL;
 128
 129         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 130                 rssi = IWL_MIN_RSSI_VAL;
 131
 132         switch (band) {
 133         case IEEE80211_BAND_2GHZ:
 134                 tpt_table = iwl3945_tpt_table_g;
 135                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 136                 break;
 137
 138         case IEEE80211_BAND_5GHZ:
 139                 tpt_table = iwl3945_tpt_table_a;
 140                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 141                 break;
 142
 143         default:
 144                 BUG();
 145                 break;
 146         }
 147
 148         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 149                 index++;
 150
 151         index = min(index, (table_size - 1));
 152
 153         return tpt_table[index].index;
 154 }
 155
 156 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 157 {
 158         window->data = 0;
 159         window->success_counter = 0;
 160         window->success_ratio = -1;
 161         window->counter = 0;
 162         window->average_tpt = IWL_INV_TPT;
 163         window->stamp = 0;
 164 }
 165
 166 /**
 167  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 168  *
 169  * Returns the number of windows that have gathered data but were
 170  * not flushed.  If there were any that were not flushed, then
 171  * reschedule the rate flushing routine.
 172  */
 173 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 174 {
 175         int unflushed = 0;
 176         int i;
 177         unsigned long flags;
 178
 179         /*
 180          * For each rate, if we have collected data on that rate
 181          * and it has been more than IWL_RATE_WIN_FLUSH
 182          * since we flushed, clear out the gathered statistics
 183          */
 184         for (i = 0; i < IWL_RATE_COUNT; i++) {
 185                 if (!rs_sta->win[i].counter)
 186                         continue;
 187
 188                 spin_lock_irqsave(&rs_sta->lock, flags);
 189                 if (time_after(jiffies, rs_sta->win[i].stamp +
 190                                IWL_RATE_WIN_FLUSH)) {
 191                         IWL_DEBUG_RATE("flushing %d samples of rate "
 192                                        "index %d\n",
 193                                        rs_sta->win[i].counter, i);
 194                         iwl3945_clear_window(&rs_sta->win[i]);
 195                 } else
 196                         unflushed++;
 197                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 198         }
 199
 200         return unflushed;
 201 }
 202
 203 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 204 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 205
 206 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 207 {
 208         struct iwl3945_rs_sta *rs_sta = (void *)data;
 209         int unflushed = 0;
 210         unsigned long flags;
 211         u32 packet_count, duration, pps;
 212
 213         IWL_DEBUG_RATE("enter\n");
 214
 215         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 216
 217         spin_lock_irqsave(&rs_sta->lock, flags);
 218
 219         rs_sta->flush_pending = 0;
 220
 221         /* Number of packets Rx'd since last time this timer ran */
 222         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 223
 224         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 225
 226         if (unflushed) {
 227                 duration =
 228                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 229 /*              duration = jiffies_to_msecs(rs_sta->flush_time); */
 230
 231                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 232                                packet_count, duration);
 233
 234                 /* Determine packets per second */
 235                 if (duration)
 236                         pps = (packet_count * 1000) / duration;
 237                 else
 238                         pps = 0;
 239
 240                 if (pps) {
 241                         duration = IWL_RATE_FLUSH_MAX / pps;
 242                         if (duration < IWL_RATE_FLUSH_MIN)
 243                                 duration = IWL_RATE_FLUSH_MIN;
 244                 } else
 245                         duration = IWL_RATE_FLUSH_MAX;
 246
 247                 rs_sta->flush_time = msecs_to_jiffies(duration);
 248
 249                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 250                                duration, packet_count);
 251
 252                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 253                           rs_sta->flush_time);
 254
 255                 rs_sta->last_partial_flush = jiffies;
 256         }
 257
 258         /* If there weren't any unflushed entries, we don't schedule the timer
 259          * to run again */
 260
 261         rs_sta->last_flush = jiffies;
 262
 263         spin_unlock_irqrestore(&rs_sta->lock, flags);
 264
 265         IWL_DEBUG_RATE("leave\n");
 266 }
 267
 268 /**
 269  * iwl3945_collect_tx_data - Update the success/failure sliding window
 270  *
 271  * We keep a sliding window of the last 64 packets transmitted
 272  * at this rate.  window->data contains the bitmask of successful
 273  * packets.
 274  */
 275 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 276                                 struct iwl3945_rate_scale_data *window,
 277                                 int success, int retries)
 278 {
 279         unsigned long flags;
 280
 281         if (!retries) {
 282                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 283                 return;
 284         }
 285
 286         while (retries--) {
 287                 spin_lock_irqsave(&rs_sta->lock, flags);
 288
 289                 /* If we have filled up the window then subtract one from the
 290                  * success counter if the high-bit is counting toward
 291                  * success */
 292                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 293                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 294                                 window->success_counter--;
 295                 } else
 296                         window->counter++;
 297
 298                 /* Slide the window to the left one bit */
 299                 window->data = (window->data << 1);
 300
 301                 /* If this packet was a success then set the low bit high */
 302                 if (success) {
 303                         window->success_counter++;
 304                         window->data |= 1;
 305                 }
 306
 307                 /* window->counter can't be 0 -- it is either >0 or
 308                  * IWL_RATE_MAX_WINDOW */
 309                 window->success_ratio = 12800 * window->success_counter /
 310                     window->counter;
 311
 312                 /* Tag this window as having been updated */
 313                 window->stamp = jiffies;
 314
 315                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 316         }
 317 }
 318
 319 static void rs_rate_init(void *priv_rate, void *priv_sta,
 320                          struct ieee80211_local *local, struct sta_info *sta)
 321 {
 322         int i;
 323
 324         IWL_DEBUG_RATE("enter\n");
 325
 326         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 327          * the lowest or the highest rate.. Could consider using RSSI from
 328          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 329          * after assoc.. */
 330
 331         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 332                 if (sta->supp_rates[local->hw.conf.channel->band] & (1 << i)) {
 333                         sta->txrate_idx = i;
 334                         break;
 335                 }
 336         }
 337
 338         sta->last_txrate_idx = sta->txrate_idx;
 339
 340         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 341         if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ)
 342                 sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 343
 344         IWL_DEBUG_RATE("leave\n");
 345 }
 346
 347 static void *rs_alloc(struct ieee80211_local *local)
 348 {
 349         return local->hw.priv;
 350 }
 351
 352 /* rate scale requires free function to be implemented */
 353 static void rs_free(void *priv)
 354 {
 355         return;
 356 }
 357 static void rs_clear(void *priv)
 358 {
 359         return;
 360 }
 361
 362
 363 static void *rs_alloc_sta(void *priv, gfp_t gfp)
 364 {
 365         struct iwl3945_rs_sta *rs_sta;
 366         int i;
 367
 368         IWL_DEBUG_RATE("enter\n");
 369
 370         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 371         if (!rs_sta) {
 372                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 373                 return NULL;
 374         }
 375
 376         spin_lock_init(&rs_sta->lock);
 377
 378         rs_sta->start_rate = IWL_RATE_INVALID;
 379
 380         /* default to just 802.11b */
 381         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 382
 383         rs_sta->last_partial_flush = jiffies;
 384         rs_sta->last_flush = jiffies;
 385         rs_sta->flush_time = IWL_RATE_FLUSH;
 386         rs_sta->last_tx_packets = 0;
 387         rs_sta->ibss_sta_added = 0;
 388
 389         init_timer(&rs_sta->rate_scale_flush);
 390         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 391         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 392
 393         for (i = 0; i < IWL_RATE_COUNT; i++)
 394                 iwl3945_clear_window(&rs_sta->win[i]);
 395
 396         IWL_DEBUG_RATE("leave\n");
 397
 398         return rs_sta;
 399 }
 400
 401 static void rs_free_sta(void *priv, void *priv_sta)
 402 {
 403         struct iwl3945_rs_sta *rs_sta = priv_sta;
 404
 405         IWL_DEBUG_RATE("enter\n");
 406         del_timer_sync(&rs_sta->rate_scale_flush);
 407         kfree(rs_sta);
 408         IWL_DEBUG_RATE("leave\n");
 409 }
 410
 411
 412 /*
 413  * get ieee prev rate from rate scale table.
 414  * for A and B mode we need to overright prev
 415  * value
 416  */
 417 static int rs_adjust_next_rate(struct iwl3945_priv *priv, int rate)
 418 {
 419         int next_rate = iwl3945_get_prev_ieee_rate(rate);
 420
 421         switch (priv->band) {
 422         case IEEE80211_BAND_5GHZ:
 423                 if (rate == IWL_RATE_12M_INDEX)
 424                         next_rate = IWL_RATE_9M_INDEX;
 425                 else if (rate == IWL_RATE_6M_INDEX)
 426                         next_rate = IWL_RATE_6M_INDEX;
 427                 break;
 428 /* XXX cannot be invoked in current mac80211 so not a regression
 429         case MODE_IEEE80211B:
 430                 if (rate == IWL_RATE_11M_INDEX_TABLE)
 431                         next_rate = IWL_RATE_5M_INDEX_TABLE;
 432                 break;
 433  */
 434         default:
 435                 break;
 436         }
 437
 438         return next_rate;
 439 }
 440 /**
 441  * rs_tx_status - Update rate control values based on Tx results
 442  *
 443  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 444  * the hardware for each rate.
 445  */
 446 static void rs_tx_status(void *priv_rate,
 447                          struct net_device *dev,
 448                          struct sk_buff *skb)
 449 {
 450         u8 retries, current_count;
 451         int scale_rate_index, first_index, last_index;
 452         unsigned long flags;
 453         struct sta_info *sta;
 454         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 455         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 456         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 457         struct iwl3945_rs_sta *rs_sta;
 458         struct ieee80211_supported_band *sband;
 459         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 460
 461         IWL_DEBUG_RATE("enter\n");
 462
 463         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 464
 465
 466         retries = info->status.retry_count;
 467         first_index = sband->bitrates[info->tx_rate_idx].hw_value;
 468         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 469                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 470                 return;
 471         }
 472
 473         rcu_read_lock();
 474
 475         sta = sta_info_get(local, hdr->addr1);
 476         if (!sta || !sta->rate_ctrl_priv) {
 477                 rcu_read_unlock();
 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                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 529                        "success" : "failure");
 530         iwl3945_collect_tx_data(rs_sta,
 531                             &rs_sta->win[last_index],
 532                             info->flags & IEEE80211_TX_STAT_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         rcu_read_unlock();
 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 *sband,
 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_INV_TPT;
 647         int low_tpt = IWL_INV_TPT;
 648         int high_tpt = IWL_INV_TPT;
 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         rcu_read_lock();
 662
 663         sta = sta_info_get(local, hdr->addr1);
 664
 665         /* Send management frames and broadcast/multicast data using lowest
 666          * rate. */
 667         fc = le16_to_cpu(hdr->frame_control);
 668         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 669             is_multicast_ether_addr(hdr->addr1) ||
 670             !sta || !sta->rate_ctrl_priv) {
 671                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 672                 sel->rate_idx = rate_lowest_index(local, sband, sta);
 673                 rcu_read_unlock();
 674                 return;
 675         }
 676
 677         rate_mask = sta->supp_rates[sband->band];
 678         index = min(sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 679
 680         if (sband->band == IEEE80211_BAND_5GHZ)
 681                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 682
 683         rs_sta = (void *)sta->rate_ctrl_priv;
 684
 685         if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 686             !rs_sta->ibss_sta_added) {
 687                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 688
 689                 if (sta_id == IWL_INVALID_STATION) {
 690                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 691                                        print_mac(mac, hdr->addr1));
 692                         sta_id = iwl3945_add_station(priv,
 693                                     hdr->addr1, 0, CMD_ASYNC);
 694                 }
 695                 if (sta_id != IWL_INVALID_STATION)
 696                         rs_sta->ibss_sta_added = 1;
 697         }
 698
 699         spin_lock_irqsave(&rs_sta->lock, flags);
 700
 701         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 702                 index = rs_sta->start_rate;
 703                 rs_sta->start_rate = IWL_RATE_INVALID;
 704         }
 705
 706         window = &(rs_sta->win[index]);
 707
 708         fail_count = window->counter - window->success_counter;
 709
 710         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 711              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 712                 window->average_tpt = IWL_INV_TPT;
 713                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 714
 715                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 716                                "counter: %d, success_counter: %d, "
 717                                "expected_tpt is %sNULL\n",
 718                                index,
 719                                window->counter,
 720                                window->success_counter,
 721                                rs_sta->expected_tpt ? "not " : "");
 722                 goto out;
 723
 724         }
 725
 726         window->average_tpt = ((window->success_ratio *
 727                                 rs_sta->expected_tpt[index] + 64) / 128);
 728         current_tpt = window->average_tpt;
 729
 730         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 731                                              sband->band);
 732         low = high_low & 0xff;
 733         high = (high_low >> 8) & 0xff;
 734
 735         if (low != IWL_RATE_INVALID)
 736                 low_tpt = rs_sta->win[low].average_tpt;
 737
 738         if (high != IWL_RATE_INVALID)
 739                 high_tpt = rs_sta->win[high].average_tpt;
 740
 741         spin_unlock_irqrestore(&rs_sta->lock, flags);
 742
 743         scale_action = 1;
 744
 745         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 746                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 747                 scale_action = -1;
 748         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 749                 scale_action = 1;
 750         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 751                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 752                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 753                                "current_tpt [%d]\n",
 754                                low_tpt, high_tpt, current_tpt);
 755                 scale_action = 0;
 756         } else {
 757                 if (high_tpt != IWL_INV_TPT) {
 758                         if (high_tpt > current_tpt)
 759                                 scale_action = 1;
 760                         else {
 761                                 IWL_DEBUG_RATE
 762                                     ("decrease rate because of high tpt\n");
 763                                 scale_action = -1;
 764                         }
 765                 } else if (low_tpt != IWL_INV_TPT) {
 766                         if (low_tpt > current_tpt) {
 767                                 IWL_DEBUG_RATE
 768                                     ("decrease rate because of low tpt\n");
 769                                 scale_action = -1;
 770                         } else
 771                                 scale_action = 1;
 772                 }
 773         }
 774
 775         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 776             (current_tpt > window->average_tpt)) {
 777                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 778                                "current_tpt [%d] > average_tpt [%d]\n",
 779                                window->success_ratio,
 780                                current_tpt, window->average_tpt);
 781                 scale_action = 0;
 782         }
 783
 784         switch (scale_action) {
 785         case -1:
 786                 if (low != IWL_RATE_INVALID)
 787                         index = low;
 788                 break;
 789
 790         case 1:
 791                 if (high != IWL_RATE_INVALID)
 792                         index = high;
 793
 794                 break;
 795
 796         case 0:
 797         default:
 798                 break;
 799         }
 800
 801         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 802                        index, scale_action, low, high);
 803
 804  out:
 805
 806         sta->last_txrate_idx = index;
 807         if (sband->band == IEEE80211_BAND_5GHZ)
 808                 sta->txrate_idx = sta->last_txrate_idx - IWL_FIRST_OFDM_RATE;
 809         else
 810                 sta->txrate_idx = sta->last_txrate_idx;
 811
 812         rcu_read_unlock();
 813
 814         IWL_DEBUG_RATE("leave: %d\n", index);
 815
 816         sel->rate_idx = sta->txrate_idx;
 817 }
 818
 819 static struct rate_control_ops rs_ops = {
 820         .module = NULL,
 821         .name = RS_NAME,
 822         .tx_status = rs_tx_status,
 823         .get_rate = rs_get_rate,
 824         .rate_init = rs_rate_init,
 825         .clear = rs_clear,
 826         .alloc = rs_alloc,
 827         .free = rs_free,
 828         .alloc_sta = rs_alloc_sta,
 829         .free_sta = rs_free_sta,
 830 };
 831
 832 int iwl3945_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 833 {
 834         struct ieee80211_local *local = hw_to_local(hw);
 835         struct iwl3945_priv *priv = hw->priv;
 836         struct iwl3945_rs_sta *rs_sta;
 837         struct sta_info *sta;
 838         unsigned long flags;
 839         int count = 0, i;
 840         u32 samples = 0, success = 0, good = 0;
 841         unsigned long now = jiffies;
 842         u32 max_time = 0;
 843
 844         rcu_read_lock();
 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                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 850                 else
 851                         IWL_DEBUG_RATE("leave - no station!\n");
 852                 rcu_read_unlock();
 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         rcu_read_unlock();
 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         rcu_read_lock();
 931
 932         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 933         if (!sta || !sta->rate_ctrl_priv) {
 934                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 935                 rcu_read_unlock();
 936                 return;
 937         }
 938
 939         rs_sta = (void *)sta->rate_ctrl_priv;
 940
 941         spin_lock_irqsave(&rs_sta->lock, flags);
 942
 943         rs_sta->tgg = 0;
 944         switch (priv->band) {
 945         case IEEE80211_BAND_2GHZ:
 946                 /* TODO: this always does G, not a regression */
 947                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 948                         rs_sta->tgg = 1;
 949                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 950                 } else
 951                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 952                 break;
 953
 954         case IEEE80211_BAND_5GHZ:
 955                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 956                 break;
 957         case IEEE80211_NUM_BANDS:
 958                 BUG();
 959                 break;
 960         }
 961
 962         rcu_read_unlock();
 963         spin_unlock_irqrestore(&rs_sta->lock, flags);
 964
 965         rssi = priv->last_rx_rssi;
 966         if (rssi == 0)
 967                 rssi = IWL_MIN_RSSI_VAL;
 968
 969         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 970
 971         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 972
 973         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 974                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 975                        iwl3945_rates[rs_sta->start_rate].plcp);
 976 }
 977
 978 int iwl3945_rate_control_register(void)
 979 {
 980         return ieee80211_rate_control_register(&rs_ops);
 981 }
 982
 983 void iwl3945_rate_control_unregister(void)
 984 {
 985         ieee80211_rate_control_unregister(&rs_ops);
 986 }
 987
 988