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         /* used to be in sta_info */
  70         int last_txrate_idx;
  71 };
  72
  73 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  74         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  75 };
  76
  77 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  78         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  79 };
  80
  81 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  82         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  83 };
  84
  85 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  86         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  87 };
  88
  89 struct iwl3945_tpt_entry {
  90         s8 min_rssi;
  91         u8 index;
  92 };
  93
  94 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  95         {-60, IWL_RATE_54M_INDEX},
  96         {-64, IWL_RATE_48M_INDEX},
  97         {-72, IWL_RATE_36M_INDEX},
  98         {-80, IWL_RATE_24M_INDEX},
  99         {-84, IWL_RATE_18M_INDEX},
 100         {-85, IWL_RATE_12M_INDEX},
 101         {-87, IWL_RATE_9M_INDEX},
 102         {-89, IWL_RATE_6M_INDEX}
 103 };
 104
 105 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 106         {-60, IWL_RATE_54M_INDEX},
 107         {-64, IWL_RATE_48M_INDEX},
 108         {-68, IWL_RATE_36M_INDEX},
 109         {-80, IWL_RATE_24M_INDEX},
 110         {-84, IWL_RATE_18M_INDEX},
 111         {-85, IWL_RATE_12M_INDEX},
 112         {-86, IWL_RATE_11M_INDEX},
 113         {-88, IWL_RATE_5M_INDEX},
 114         {-90, IWL_RATE_2M_INDEX},
 115         {-92, IWL_RATE_1M_INDEX}
 116 };
 117
 118 #define IWL_RATE_MAX_WINDOW          62
 119 #define IWL_RATE_FLUSH        (3*HZ/10)
 120 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 121 #define IWL_RATE_HIGH_TH          11520
 122 #define IWL_RATE_MIN_FAILURE_TH       8
 123 #define IWL_RATE_MIN_SUCCESS_TH       8
 124 #define IWL_RATE_DECREASE_TH       1920
 125
 126 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 127 {
 128         u32 index = 0;
 129         u32 table_size = 0;
 130         struct iwl3945_tpt_entry *tpt_table = NULL;
 131
 132         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 133                 rssi = IWL_MIN_RSSI_VAL;
 134
 135         switch (band) {
 136         case IEEE80211_BAND_2GHZ:
 137                 tpt_table = iwl3945_tpt_table_g;
 138                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 139                 break;
 140
 141         case IEEE80211_BAND_5GHZ:
 142                 tpt_table = iwl3945_tpt_table_a;
 143                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 144                 break;
 145
 146         default:
 147                 BUG();
 148                 break;
 149         }
 150
 151         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 152                 index++;
 153
 154         index = min(index, (table_size - 1));
 155
 156         return tpt_table[index].index;
 157 }
 158
 159 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 160 {
 161         window->data = 0;
 162         window->success_counter = 0;
 163         window->success_ratio = -1;
 164         window->counter = 0;
 165         window->average_tpt = IWL_INV_TPT;
 166         window->stamp = 0;
 167 }
 168
 169 /**
 170  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 171  *
 172  * Returns the number of windows that have gathered data but were
 173  * not flushed.  If there were any that were not flushed, then
 174  * reschedule the rate flushing routine.
 175  */
 176 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 177 {
 178         int unflushed = 0;
 179         int i;
 180         unsigned long flags;
 181
 182         /*
 183          * For each rate, if we have collected data on that rate
 184          * and it has been more than IWL_RATE_WIN_FLUSH
 185          * since we flushed, clear out the gathered statistics
 186          */
 187         for (i = 0; i < IWL_RATE_COUNT; i++) {
 188                 if (!rs_sta->win[i].counter)
 189                         continue;
 190
 191                 spin_lock_irqsave(&rs_sta->lock, flags);
 192                 if (time_after(jiffies, rs_sta->win[i].stamp +
 193                                IWL_RATE_WIN_FLUSH)) {
 194                         IWL_DEBUG_RATE("flushing %d samples of rate "
 195                                        "index %d\n",
 196                                        rs_sta->win[i].counter, i);
 197                         iwl3945_clear_window(&rs_sta->win[i]);
 198                 } else
 199                         unflushed++;
 200                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 201         }
 202
 203         return unflushed;
 204 }
 205
 206 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 207 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 208
 209 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 210 {
 211         struct iwl3945_rs_sta *rs_sta = (void *)data;
 212         int unflushed = 0;
 213         unsigned long flags;
 214         u32 packet_count, duration, pps;
 215
 216         IWL_DEBUG_RATE("enter\n");
 217
 218         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 219
 220         spin_lock_irqsave(&rs_sta->lock, flags);
 221
 222         rs_sta->flush_pending = 0;
 223
 224         /* Number of packets Rx'd since last time this timer ran */
 225         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 226
 227         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 228
 229         if (unflushed) {
 230                 duration =
 231                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 232 /*              duration = jiffies_to_msecs(rs_sta->flush_time); */
 233
 234                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 235                                packet_count, duration);
 236
 237                 /* Determine packets per second */
 238                 if (duration)
 239                         pps = (packet_count * 1000) / duration;
 240                 else
 241                         pps = 0;
 242
 243                 if (pps) {
 244                         duration = IWL_RATE_FLUSH_MAX / pps;
 245                         if (duration < IWL_RATE_FLUSH_MIN)
 246                                 duration = IWL_RATE_FLUSH_MIN;
 247                 } else
 248                         duration = IWL_RATE_FLUSH_MAX;
 249
 250                 rs_sta->flush_time = msecs_to_jiffies(duration);
 251
 252                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 253                                duration, packet_count);
 254
 255                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 256                           rs_sta->flush_time);
 257
 258                 rs_sta->last_partial_flush = jiffies;
 259         }
 260
 261         /* If there weren't any unflushed entries, we don't schedule the timer
 262          * to run again */
 263
 264         rs_sta->last_flush = jiffies;
 265
 266         spin_unlock_irqrestore(&rs_sta->lock, flags);
 267
 268         IWL_DEBUG_RATE("leave\n");
 269 }
 270
 271 /**
 272  * iwl3945_collect_tx_data - Update the success/failure sliding window
 273  *
 274  * We keep a sliding window of the last 64 packets transmitted
 275  * at this rate.  window->data contains the bitmask of successful
 276  * packets.
 277  */
 278 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 279                                 struct iwl3945_rate_scale_data *window,
 280                                 int success, int retries)
 281 {
 282         unsigned long flags;
 283
 284         if (!retries) {
 285                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 286                 return;
 287         }
 288
 289         while (retries--) {
 290                 spin_lock_irqsave(&rs_sta->lock, flags);
 291
 292                 /* If we have filled up the window then subtract one from the
 293                  * success counter if the high-bit is counting toward
 294                  * success */
 295                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 296                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 297                                 window->success_counter--;
 298                 } else
 299                         window->counter++;
 300
 301                 /* Slide the window to the left one bit */
 302                 window->data = (window->data << 1);
 303
 304                 /* If this packet was a success then set the low bit high */
 305                 if (success) {
 306                         window->success_counter++;
 307                         window->data |= 1;
 308                 }
 309
 310                 /* window->counter can't be 0 -- it is either >0 or
 311                  * IWL_RATE_MAX_WINDOW */
 312                 window->success_ratio = 12800 * window->success_counter /
 313                     window->counter;
 314
 315                 /* Tag this window as having been updated */
 316                 window->stamp = jiffies;
 317
 318                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 319         }
 320 }
 321
 322 static void rs_rate_init(void *priv_rate, void *priv_sta,
 323                          struct ieee80211_local *local, struct sta_info *sta)
 324 {
 325         struct iwl3945_rs_sta *rs_sta = (void *)sta->rate_ctrl_priv;
 326         int i;
 327
 328         IWL_DEBUG_RATE("enter\n");
 329
 330         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 331          * the lowest or the highest rate.. Could consider using RSSI from
 332          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 333          * after assoc.. */
 334
 335         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 336                 if (sta->sta.supp_rates[local->hw.conf.channel->band] & (1 << i)) {
 337                         sta->txrate_idx = i;
 338                         break;
 339                 }
 340         }
 341
 342         rs_sta->last_txrate_idx = sta->txrate_idx;
 343
 344         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 345         if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ)
 346                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 347
 348         IWL_DEBUG_RATE("leave\n");
 349 }
 350
 351 static void *rs_alloc(struct ieee80211_local *local)
 352 {
 353         return local->hw.priv;
 354 }
 355
 356 /* rate scale requires free function to be implemented */
 357 static void rs_free(void *priv)
 358 {
 359         return;
 360 }
 361 static void rs_clear(void *priv)
 362 {
 363         return;
 364 }
 365
 366
 367 static void *rs_alloc_sta(void *priv, gfp_t gfp)
 368 {
 369         struct iwl3945_rs_sta *rs_sta;
 370         int i;
 371
 372         IWL_DEBUG_RATE("enter\n");
 373
 374         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 375         if (!rs_sta) {
 376                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 377                 return NULL;
 378         }
 379
 380         spin_lock_init(&rs_sta->lock);
 381
 382         rs_sta->start_rate = IWL_RATE_INVALID;
 383
 384         /* default to just 802.11b */
 385         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 386
 387         rs_sta->last_partial_flush = jiffies;
 388         rs_sta->last_flush = jiffies;
 389         rs_sta->flush_time = IWL_RATE_FLUSH;
 390         rs_sta->last_tx_packets = 0;
 391         rs_sta->ibss_sta_added = 0;
 392
 393         init_timer(&rs_sta->rate_scale_flush);
 394         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 395         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 396
 397         for (i = 0; i < IWL_RATE_COUNT; i++)
 398                 iwl3945_clear_window(&rs_sta->win[i]);
 399
 400         IWL_DEBUG_RATE("leave\n");
 401
 402         return rs_sta;
 403 }
 404
 405 static void rs_free_sta(void *priv, void *priv_sta)
 406 {
 407         struct iwl3945_rs_sta *rs_sta = priv_sta;
 408
 409         IWL_DEBUG_RATE("enter\n");
 410         del_timer_sync(&rs_sta->rate_scale_flush);
 411         kfree(rs_sta);
 412         IWL_DEBUG_RATE("leave\n");
 413 }
 414
 415
 416 /*
 417  * get ieee prev rate from rate scale table.
 418  * for A and B mode we need to overright prev
 419  * value
 420  */
 421 static int rs_adjust_next_rate(struct iwl3945_priv *priv, int rate)
 422 {
 423         int next_rate = iwl3945_get_prev_ieee_rate(rate);
 424
 425         switch (priv->band) {
 426         case IEEE80211_BAND_5GHZ:
 427                 if (rate == IWL_RATE_12M_INDEX)
 428                         next_rate = IWL_RATE_9M_INDEX;
 429                 else if (rate == IWL_RATE_6M_INDEX)
 430                         next_rate = IWL_RATE_6M_INDEX;
 431                 break;
 432 /* XXX cannot be invoked in current mac80211 so not a regression
 433         case MODE_IEEE80211B:
 434                 if (rate == IWL_RATE_11M_INDEX_TABLE)
 435                         next_rate = IWL_RATE_5M_INDEX_TABLE;
 436                 break;
 437  */
 438         default:
 439                 break;
 440         }
 441
 442         return next_rate;
 443 }
 444 /**
 445  * rs_tx_status - Update rate control values based on Tx results
 446  *
 447  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 448  * the hardware for each rate.
 449  */
 450 static void rs_tx_status(void *priv_rate,
 451                          struct net_device *dev,
 452                          struct sk_buff *skb)
 453 {
 454         u8 retries, current_count;
 455         int scale_rate_index, first_index, last_index;
 456         unsigned long flags;
 457         struct sta_info *sta;
 458         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 459         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 460         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 461         struct iwl3945_rs_sta *rs_sta;
 462         struct ieee80211_supported_band *sband;
 463         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 464
 465         IWL_DEBUG_RATE("enter\n");
 466
 467         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 468
 469
 470         retries = info->status.retry_count;
 471         first_index = sband->bitrates[info->tx_rate_idx].hw_value;
 472         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 473                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 474                 return;
 475         }
 476
 477         rcu_read_lock();
 478
 479         sta = sta_info_get(local, hdr->addr1);
 480         if (!sta || !sta->rate_ctrl_priv) {
 481                 rcu_read_unlock();
 482                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 483                 return;
 484         }
 485
 486         rs_sta = (void *)sta->rate_ctrl_priv;
 487
 488         rs_sta->tx_packets++;
 489
 490         scale_rate_index = first_index;
 491         last_index = first_index;
 492
 493         /*
 494          * Update the window for each rate.  We determine which rates
 495          * were Tx'd based on the total number of retries vs. the number
 496          * of retries configured for each rate -- currently set to the
 497          * priv value 'retry_rate' vs. rate specific
 498          *
 499          * On exit from this while loop last_index indicates the rate
 500          * at which the frame was finally transmitted (or failed if no
 501          * ACK)
 502          */
 503         while (retries > 0) {
 504                 if (retries < priv->retry_rate) {
 505                         current_count = retries;
 506                         last_index = scale_rate_index;
 507                 } else {
 508                         current_count = priv->retry_rate;
 509                         last_index = rs_adjust_next_rate(priv,
 510                                                          scale_rate_index);
 511                 }
 512
 513                 /* Update this rate accounting for as many retries
 514                  * as was used for it (per current_count) */
 515                 iwl3945_collect_tx_data(rs_sta,
 516                                     &rs_sta->win[scale_rate_index],
 517                                     0, current_count);
 518                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 519                                scale_rate_index, current_count);
 520
 521                 retries -= current_count;
 522
 523                 if (retries)
 524                         scale_rate_index =
 525                             rs_adjust_next_rate(priv, scale_rate_index);
 526         }
 527
 528
 529         /* Update the last index window with success/failure based on ACK */
 530         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 531                        last_index,
 532                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 533                        "success" : "failure");
 534         iwl3945_collect_tx_data(rs_sta,
 535                             &rs_sta->win[last_index],
 536                             info->flags & IEEE80211_TX_STAT_ACK, 1);
 537
 538         /* We updated the rate scale window -- if its been more than
 539          * flush_time since the last run, schedule the flush
 540          * again */
 541         spin_lock_irqsave(&rs_sta->lock, flags);
 542
 543         if (!rs_sta->flush_pending &&
 544             time_after(jiffies, rs_sta->last_partial_flush +
 545                        rs_sta->flush_time)) {
 546
 547                 rs_sta->flush_pending = 1;
 548                 mod_timer(&rs_sta->rate_scale_flush,
 549                           jiffies + rs_sta->flush_time);
 550         }
 551
 552         spin_unlock_irqrestore(&rs_sta->lock, flags);
 553
 554         rcu_read_unlock();
 555
 556         IWL_DEBUG_RATE("leave\n");
 557
 558         return;
 559 }
 560
 561 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 562                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 563 {
 564         u8 high = IWL_RATE_INVALID;
 565         u8 low = IWL_RATE_INVALID;
 566
 567         /* 802.11A walks to the next literal adjacent rate in
 568          * the rate table */
 569         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 570                 int i;
 571                 u32 mask;
 572
 573                 /* Find the previous rate that is in the rate mask */
 574                 i = index - 1;
 575                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 576                         if (rate_mask & mask) {
 577                                 low = i;
 578                                 break;
 579                         }
 580                 }
 581
 582                 /* Find the next rate that is in the rate mask */
 583                 i = index + 1;
 584                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 585                         if (rate_mask & mask) {
 586                                 high = i;
 587                                 break;
 588                         }
 589                 }
 590
 591                 return (high << 8) | low;
 592         }
 593
 594         low = index;
 595         while (low != IWL_RATE_INVALID) {
 596                 if (rs_sta->tgg)
 597                         low = iwl3945_rates[low].prev_rs_tgg;
 598                 else
 599                         low = iwl3945_rates[low].prev_rs;
 600                 if (low == IWL_RATE_INVALID)
 601                         break;
 602                 if (rate_mask & (1 << low))
 603                         break;
 604                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 605         }
 606
 607         high = index;
 608         while (high != IWL_RATE_INVALID) {
 609                 if (rs_sta->tgg)
 610                         high = iwl3945_rates[high].next_rs_tgg;
 611                 else
 612                         high = iwl3945_rates[high].next_rs;
 613                 if (high == IWL_RATE_INVALID)
 614                         break;
 615                 if (rate_mask & (1 << high))
 616                         break;
 617                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 618         }
 619
 620         return (high << 8) | low;
 621 }
 622
 623 /**
 624  * rs_get_rate - find the rate for the requested packet
 625  *
 626  * Returns the ieee80211_rate structure allocated by the driver.
 627  *
 628  * The rate control algorithm has no internal mapping between hw_mode's
 629  * rate ordering and the rate ordering used by the rate control algorithm.
 630  *
 631  * The rate control algorithm uses a single table of rates that goes across
 632  * the entire A/B/G spectrum vs. being limited to just one particular
 633  * hw_mode.
 634  *
 635  * As such, we can't convert the index obtained below into the hw_mode's
 636  * rate table and must reference the driver allocated rate table
 637  *
 638  */
 639 static void rs_get_rate(void *priv_rate, struct net_device *dev,
 640                         struct ieee80211_supported_band *sband,
 641                         struct sk_buff *skb,
 642                         struct rate_selection *sel)
 643 {
 644         u8 low = IWL_RATE_INVALID;
 645         u8 high = IWL_RATE_INVALID;
 646         u16 high_low;
 647         int index;
 648         struct iwl3945_rs_sta *rs_sta;
 649         struct iwl3945_rate_scale_data *window = NULL;
 650         int current_tpt = IWL_INV_TPT;
 651         int low_tpt = IWL_INV_TPT;
 652         int high_tpt = IWL_INV_TPT;
 653         u32 fail_count;
 654         s8 scale_action = 0;
 655         unsigned long flags;
 656         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 657         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 658         struct sta_info *sta;
 659         u16 fc, rate_mask;
 660         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 661         DECLARE_MAC_BUF(mac);
 662
 663         IWL_DEBUG_RATE("enter\n");
 664
 665         rcu_read_lock();
 666
 667         sta = sta_info_get(local, hdr->addr1);
 668
 669         /* Send management frames and broadcast/multicast data using lowest
 670          * rate. */
 671         fc = le16_to_cpu(hdr->frame_control);
 672         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 673             is_multicast_ether_addr(hdr->addr1) ||
 674             !sta || !sta->rate_ctrl_priv) {
 675                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 676                 sel->rate_idx = rate_lowest_index(local, sband, sta);
 677                 rcu_read_unlock();
 678                 return;
 679         }
 680
 681         rs_sta = (void *)sta->rate_ctrl_priv;
 682
 683         rate_mask = sta->sta.supp_rates[sband->band];
 684         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 685
 686         if (sband->band == IEEE80211_BAND_5GHZ)
 687                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 688
 689         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 690             !rs_sta->ibss_sta_added) {
 691                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 692
 693                 if (sta_id == IWL_INVALID_STATION) {
 694                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 695                                        print_mac(mac, hdr->addr1));
 696                         sta_id = iwl3945_add_station(priv,
 697                                     hdr->addr1, 0, CMD_ASYNC);
 698                 }
 699                 if (sta_id != IWL_INVALID_STATION)
 700                         rs_sta->ibss_sta_added = 1;
 701         }
 702
 703         spin_lock_irqsave(&rs_sta->lock, flags);
 704
 705         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 706                 index = rs_sta->start_rate;
 707                 rs_sta->start_rate = IWL_RATE_INVALID;
 708         }
 709
 710         window = &(rs_sta->win[index]);
 711
 712         fail_count = window->counter - window->success_counter;
 713
 714         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 715              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 716                 window->average_tpt = IWL_INV_TPT;
 717                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 718
 719                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 720                                "counter: %d, success_counter: %d, "
 721                                "expected_tpt is %sNULL\n",
 722                                index,
 723                                window->counter,
 724                                window->success_counter,
 725                                rs_sta->expected_tpt ? "not " : "");
 726                 goto out;
 727
 728         }
 729
 730         window->average_tpt = ((window->success_ratio *
 731                                 rs_sta->expected_tpt[index] + 64) / 128);
 732         current_tpt = window->average_tpt;
 733
 734         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 735                                              sband->band);
 736         low = high_low & 0xff;
 737         high = (high_low >> 8) & 0xff;
 738
 739         if (low != IWL_RATE_INVALID)
 740                 low_tpt = rs_sta->win[low].average_tpt;
 741
 742         if (high != IWL_RATE_INVALID)
 743                 high_tpt = rs_sta->win[high].average_tpt;
 744
 745         spin_unlock_irqrestore(&rs_sta->lock, flags);
 746
 747         scale_action = 1;
 748
 749         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 750                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 751                 scale_action = -1;
 752         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 753                 scale_action = 1;
 754         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 755                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 756                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 757                                "current_tpt [%d]\n",
 758                                low_tpt, high_tpt, current_tpt);
 759                 scale_action = 0;
 760         } else {
 761                 if (high_tpt != IWL_INV_TPT) {
 762                         if (high_tpt > current_tpt)
 763                                 scale_action = 1;
 764                         else {
 765                                 IWL_DEBUG_RATE
 766                                     ("decrease rate because of high tpt\n");
 767                                 scale_action = -1;
 768                         }
 769                 } else if (low_tpt != IWL_INV_TPT) {
 770                         if (low_tpt > current_tpt) {
 771                                 IWL_DEBUG_RATE
 772                                     ("decrease rate because of low tpt\n");
 773                                 scale_action = -1;
 774                         } else
 775                                 scale_action = 1;
 776                 }
 777         }
 778
 779         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 780             (current_tpt > window->average_tpt)) {
 781                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 782                                "current_tpt [%d] > average_tpt [%d]\n",
 783                                window->success_ratio,
 784                                current_tpt, window->average_tpt);
 785                 scale_action = 0;
 786         }
 787
 788         switch (scale_action) {
 789         case -1:
 790                 if (low != IWL_RATE_INVALID)
 791                         index = low;
 792                 break;
 793
 794         case 1:
 795                 if (high != IWL_RATE_INVALID)
 796                         index = high;
 797
 798                 break;
 799
 800         case 0:
 801         default:
 802                 break;
 803         }
 804
 805         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 806                        index, scale_action, low, high);
 807
 808  out:
 809
 810         rs_sta->last_txrate_idx = index;
 811         if (sband->band == IEEE80211_BAND_5GHZ)
 812                 sta->txrate_idx = rs_sta->last_txrate_idx - IWL_FIRST_OFDM_RATE;
 813         else
 814                 sta->txrate_idx = rs_sta->last_txrate_idx;
 815
 816         rcu_read_unlock();
 817
 818         IWL_DEBUG_RATE("leave: %d\n", index);
 819
 820         sel->rate_idx = sta->txrate_idx;
 821 }
 822
 823 static struct rate_control_ops rs_ops = {
 824         .module = NULL,
 825         .name = RS_NAME,
 826         .tx_status = rs_tx_status,
 827         .get_rate = rs_get_rate,
 828         .rate_init = rs_rate_init,
 829         .clear = rs_clear,
 830         .alloc = rs_alloc,
 831         .free = rs_free,
 832         .alloc_sta = rs_alloc_sta,
 833         .free_sta = rs_free_sta,
 834 };
 835
 836 int iwl3945_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 837 {
 838         struct ieee80211_local *local = hw_to_local(hw);
 839         struct iwl3945_priv *priv = hw->priv;
 840         struct iwl3945_rs_sta *rs_sta;
 841         struct sta_info *sta;
 842         unsigned long flags;
 843         int count = 0, i;
 844         u32 samples = 0, success = 0, good = 0;
 845         unsigned long now = jiffies;
 846         u32 max_time = 0;
 847
 848         rcu_read_lock();
 849
 850         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 851         if (!sta || !sta->rate_ctrl_priv) {
 852                 if (sta)
 853                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 854                 else
 855                         IWL_DEBUG_RATE("leave - no station!\n");
 856                 rcu_read_unlock();
 857                 return sprintf(buf, "station %d not found\n", sta_id);
 858         }
 859
 860         rs_sta = (void *)sta->rate_ctrl_priv;
 861         spin_lock_irqsave(&rs_sta->lock, flags);
 862         i = IWL_RATE_54M_INDEX;
 863         while (1) {
 864                 u64 mask;
 865                 int j;
 866
 867                 count +=
 868                     sprintf(&buf[count], " %2dMbs: ", iwl3945_rates[i].ieee / 2);
 869
 870                 mask = (1ULL << (IWL_RATE_MAX_WINDOW - 1));
 871                 for (j = 0; j < IWL_RATE_MAX_WINDOW; j++, mask >>= 1)
 872                         buf[count++] =
 873                             (rs_sta->win[i].data & mask) ? '1' : '0';
 874
 875                 samples += rs_sta->win[i].counter;
 876                 good += rs_sta->win[i].success_counter;
 877                 success += rs_sta->win[i].success_counter *
 878                                                 iwl3945_rates[i].ieee;
 879
 880                 if (rs_sta->win[i].stamp) {
 881                         int delta =
 882                             jiffies_to_msecs(now - rs_sta->win[i].stamp);
 883
 884                         if (delta > max_time)
 885                                 max_time = delta;
 886
 887                         count += sprintf(&buf[count], "%5dms\n", delta);
 888                 } else
 889                         buf[count++] = '\n';
 890
 891                 j = iwl3945_get_prev_ieee_rate(i);
 892                 if (j == i)
 893                         break;
 894                 i = j;
 895         }
 896         spin_unlock_irqrestore(&rs_sta->lock, flags);
 897         rcu_read_unlock();
 898
 899         /* Display the average rate of all samples taken.
 900          *
 901          * NOTE:  We multiple # of samples by 2 since the IEEE measurement
 902          * added from iwl3945_rates is actually 2X the rate */
 903         if (samples)
 904                 count += sprintf(
 905                         &buf[count],
 906                         "\nAverage rate is %3d.%02dMbs over last %4dms\n"
 907                         "%3d%% success (%d good packets over %d tries)\n",
 908                         success / (2 * samples), (success * 5 / samples) % 10,
 909                         max_time, good * 100 / samples, good, samples);
 910         else
 911                 count += sprintf(&buf[count], "\nAverage rate: 0Mbs\n");
 912
 913         return count;
 914 }
 915
 916 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 917 {
 918         struct iwl3945_priv *priv = hw->priv;
 919         s32 rssi = 0;
 920         unsigned long flags;
 921         struct ieee80211_local *local = hw_to_local(hw);
 922         struct iwl3945_rs_sta *rs_sta;
 923         struct sta_info *sta;
 924
 925         IWL_DEBUG_RATE("enter\n");
 926
 927         if (!local->rate_ctrl->ops->name ||
 928             strcmp(local->rate_ctrl->ops->name, RS_NAME)) {
 929                 IWL_WARNING("iwl-3945-rs not selected as rate control algo!\n");
 930                 IWL_DEBUG_RATE("leave - mac80211 picked the wrong RC algo.\n");
 931                 return;
 932         }
 933
 934         rcu_read_lock();
 935
 936         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 937         if (!sta || !sta->rate_ctrl_priv) {
 938                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 939                 rcu_read_unlock();
 940                 return;
 941         }
 942
 943         rs_sta = (void *)sta->rate_ctrl_priv;
 944
 945         spin_lock_irqsave(&rs_sta->lock, flags);
 946
 947         rs_sta->tgg = 0;
 948         switch (priv->band) {
 949         case IEEE80211_BAND_2GHZ:
 950                 /* TODO: this always does G, not a regression */
 951                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 952                         rs_sta->tgg = 1;
 953                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 954                 } else
 955                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 956                 break;
 957
 958         case IEEE80211_BAND_5GHZ:
 959                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 960                 break;
 961         case IEEE80211_NUM_BANDS:
 962                 BUG();
 963                 break;
 964         }
 965
 966         rcu_read_unlock();
 967         spin_unlock_irqrestore(&rs_sta->lock, flags);
 968
 969         rssi = priv->last_rx_rssi;
 970         if (rssi == 0)
 971                 rssi = IWL_MIN_RSSI_VAL;
 972
 973         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 974
 975         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 976
 977         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 978                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 979                        iwl3945_rates[rs_sta->start_rate].plcp);
 980 }
 981
 982 int iwl3945_rate_control_register(void)
 983 {
 984         return ieee80211_rate_control_register(&rs_ops);
 985 }
 986
 987 void iwl3945_rate_control_unregister(void)
 988 {
 989         ieee80211_rate_control_unregister(&rs_ops);
 990 }
 991
 992