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

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2007 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  * James P. Ketrenos <ipw2100-admin@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/wireless.h>
  31 #include <net/mac80211.h>
  32 #include <net/ieee80211.h>
  33
  34 #include <linux/netdevice.h>
  35 #include <linux/etherdevice.h>
  36 #include <linux/delay.h>
  37
  38 #include <linux/workqueue.h>
  39
  40 #include <net/mac80211.h>
  41 #include <linux/wireless.h>
  42
  43 #include "../net/mac80211/ieee80211_rate.h"
  44
  45 #include "iwlwifi.h"
  46
  47 #define RS_NAME "iwl-3945-rs"
  48
  49 struct iwl_rate_scale_data {
  50         u64 data;
  51         s32 success_counter;
  52         s32 success_ratio;
  53         s32 counter;
  54         s32 average_tpt;
  55         unsigned long stamp;
  56 };
  57
  58 struct iwl_rate_scale_priv {
  59         spinlock_t lock;
  60         s32 *expected_tpt;
  61         unsigned long last_partial_flush;
  62         unsigned long last_flush;
  63         u32 flush_time;
  64         u32 last_tx_packets;
  65         u32 tx_packets;
  66         u8 tgg;
  67         u8 flush_pending;
  68         u8 start_rate;
  69         u8 ibss_sta_added;
  70         struct timer_list rate_scale_flush;
  71         struct iwl_rate_scale_data win[IWL_RATE_COUNT];
  72 };
  73
  74 static s32 iwl_expected_tpt_g[IWL_RATE_COUNT] = {
  75         0, 0, 76, 104, 130, 168, 191, 202, 7, 13, 35, 58
  76 };
  77
  78 static s32 iwl_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  79         0, 0, 0, 80, 93, 113, 123, 125, 7, 13, 35, 58
  80 };
  81
  82 static s32 iwl_expected_tpt_a[IWL_RATE_COUNT] = {
  83         40, 57, 72, 98, 121, 154, 177, 186, 0, 0, 0, 0
  84 };
  85
  86 static s32 iwl_expected_tpt_b[IWL_RATE_COUNT] = {
  87         0, 0, 0, 0, 0, 0, 0, 0, 7, 13, 35, 58
  88 };
  89
  90 struct iwl_tpt_entry {
  91         s8 min_rssi;
  92         u8 index;
  93 };
  94
  95 static struct iwl_tpt_entry iwl_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 iwl_tpt_entry iwl_tpt_table_b[] = {
 107         {-86, IWL_RATE_11M_INDEX},
 108         {-88, IWL_RATE_5M_INDEX},
 109         {-90, IWL_RATE_2M_INDEX},
 110         {-92, IWL_RATE_1M_INDEX}
 111
 112 };
 113
 114 static struct iwl_tpt_entry iwl_tpt_table_g[] = {
 115         {-60, IWL_RATE_54M_INDEX},
 116         {-64, IWL_RATE_48M_INDEX},
 117         {-68, IWL_RATE_36M_INDEX},
 118         {-80, IWL_RATE_24M_INDEX},
 119         {-84, IWL_RATE_18M_INDEX},
 120         {-85, IWL_RATE_12M_INDEX},
 121         {-86, IWL_RATE_11M_INDEX},
 122         {-88, IWL_RATE_5M_INDEX},
 123         {-90, IWL_RATE_2M_INDEX},
 124         {-92, IWL_RATE_1M_INDEX}
 125 };
 126
 127 #define IWL_RATE_MAX_WINDOW          62
 128 #define IWL_RATE_FLUSH        (3*HZ/10)
 129 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 130 #define IWL_RATE_HIGH_TH          11520
 131 #define IWL_RATE_MIN_FAILURE_TH       8
 132 #define IWL_RATE_MIN_SUCCESS_TH       8
 133 #define IWL_RATE_DECREASE_TH       1920
 134
 135 static u8 iwl_get_rate_index_by_rssi(s32 rssi, u8 mode)
 136 {
 137         u32 index = 0;
 138         u32 table_size = 0;
 139         struct iwl_tpt_entry *tpt_table = NULL;
 140
 141         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 142                 rssi = IWL_MIN_RSSI_VAL;
 143
 144         switch (mode) {
 145         case MODE_IEEE80211G:
 146                 tpt_table = iwl_tpt_table_g;
 147                 table_size = ARRAY_SIZE(iwl_tpt_table_g);
 148                 break;
 149
 150         case MODE_IEEE80211A:
 151                 tpt_table = iwl_tpt_table_a;
 152                 table_size = ARRAY_SIZE(iwl_tpt_table_a);
 153                 break;
 154
 155         default:
 156         case MODE_IEEE80211B:
 157                 tpt_table = iwl_tpt_table_b;
 158                 table_size = ARRAY_SIZE(iwl_tpt_table_b);
 159                 break;
 160         }
 161
 162         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 163                 index++;
 164
 165         index = min(index, (table_size - 1));
 166
 167         return tpt_table[index].index;
 168 }
 169
 170 static void iwl_clear_window(struct iwl_rate_scale_data *window)
 171 {
 172         window->data = 0;
 173         window->success_counter = 0;
 174         window->success_ratio = IWL_INVALID_VALUE;
 175         window->counter = 0;
 176         window->average_tpt = IWL_INVALID_VALUE;
 177         window->stamp = 0;
 178 }
 179
 180 /**
 181  * iwl_rate_scale_flush_windows - flush out the rate scale windows
 182  *
 183  * Returns the number of windows that have gathered data but were
 184  * not flushed.  If there were any that were not flushed, then
 185  * reschedule the rate flushing routine.
 186  */
 187 static int iwl_rate_scale_flush_windows(struct iwl_rate_scale_priv *rs_priv)
 188 {
 189         int unflushed = 0;
 190         int i;
 191         unsigned long flags;
 192
 193         /*
 194          * For each rate, if we have collected data on that rate
 195          * and it has been more than IWL_RATE_WIN_FLUSH
 196          * since we flushed, clear out the gathered statistics
 197          */
 198         for (i = 0; i < IWL_RATE_COUNT; i++) {
 199                 if (!rs_priv->win[i].counter)
 200                         continue;
 201
 202                 spin_lock_irqsave(&rs_priv->lock, flags);
 203                 if (time_after(jiffies, rs_priv->win[i].stamp +
 204                                IWL_RATE_WIN_FLUSH)) {
 205                         IWL_DEBUG_RATE("flushing %d samples of rate "
 206                                        "index %d\n",
 207                                        rs_priv->win[i].counter, i);
 208                         iwl_clear_window(&rs_priv->win[i]);
 209                 } else
 210                         unflushed++;
 211                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 212         }
 213
 214         return unflushed;
 215 }
 216
 217 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 218 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 219
 220 static void iwl_bg_rate_scale_flush(unsigned long data)
 221 {
 222         struct iwl_rate_scale_priv *rs_priv = (void *)data;
 223         int unflushed = 0;
 224         unsigned long flags;
 225         u32 packet_count, duration, pps;
 226
 227         IWL_DEBUG_RATE("enter\n");
 228
 229         unflushed = iwl_rate_scale_flush_windows(rs_priv);
 230
 231         spin_lock_irqsave(&rs_priv->lock, flags);
 232
 233         rs_priv->flush_pending = 0;
 234
 235         /* Number of packets Rx'd since last time this timer ran */
 236         packet_count = (rs_priv->tx_packets - rs_priv->last_tx_packets) + 1;
 237
 238         rs_priv->last_tx_packets = rs_priv->tx_packets + 1;
 239
 240         if (unflushed) {
 241                 duration =
 242                     jiffies_to_msecs(jiffies - rs_priv->last_partial_flush);
 243 /*              duration = jiffies_to_msecs(rs_priv->flush_time); */
 244
 245                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 246                                packet_count, duration);
 247
 248                 /* Determine packets per second */
 249                 if (duration)
 250                         pps = (packet_count * 1000) / duration;
 251                 else
 252                         pps = 0;
 253
 254                 if (pps) {
 255                         duration = IWL_RATE_FLUSH_MAX / pps;
 256                         if (duration < IWL_RATE_FLUSH_MIN)
 257                                 duration = IWL_RATE_FLUSH_MIN;
 258                 } else
 259                         duration = IWL_RATE_FLUSH_MAX;
 260
 261                 rs_priv->flush_time = msecs_to_jiffies(duration);
 262
 263                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 264                                duration, packet_count);
 265
 266                 mod_timer(&rs_priv->rate_scale_flush, jiffies +
 267                           rs_priv->flush_time);
 268
 269                 rs_priv->last_partial_flush = jiffies;
 270         }
 271
 272         /* If there weren't any unflushed entries, we don't schedule the timer
 273          * to run again */
 274
 275         rs_priv->last_flush = jiffies;
 276
 277         spin_unlock_irqrestore(&rs_priv->lock, flags);
 278
 279         IWL_DEBUG_RATE("leave\n");
 280 }
 281
 282 /**
 283  * iwl_collect_tx_data - Update the success/failure sliding window
 284  *
 285  * We keep a sliding window of the last 64 packets transmitted
 286  * at this rate.  window->data contains the bitmask of successful
 287  * packets.
 288  */
 289 static void iwl_collect_tx_data(struct iwl_rate_scale_priv *rs_priv,
 290                                 struct iwl_rate_scale_data *window,
 291                                 int success, int retries)
 292 {
 293         unsigned long flags;
 294
 295         if (!retries) {
 296                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 297                 return;
 298         }
 299
 300         while (retries--) {
 301                 spin_lock_irqsave(&rs_priv->lock, flags);
 302
 303                 /* If we have filled up the window then subtract one from the
 304                  * success counter if the high-bit is counting toward
 305                  * success */
 306                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 307                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 308                                 window->success_counter--;
 309                 } else
 310                         window->counter++;
 311
 312                 /* Slide the window to the left one bit */
 313                 window->data = (window->data << 1);
 314
 315                 /* If this packet was a success then set the low bit high */
 316                 if (success) {
 317                         window->success_counter++;
 318                         window->data |= 1;
 319                 }
 320
 321                 /* window->counter can't be 0 -- it is either >0 or
 322                  * IWL_RATE_MAX_WINDOW */
 323                 window->success_ratio = 12800 * window->success_counter /
 324                     window->counter;
 325
 326                 /* Tag this window as having been updated */
 327                 window->stamp = jiffies;
 328
 329                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 330         }
 331 }
 332
 333 static void rs_rate_init(void *priv_rate, void *priv_sta,
 334                          struct ieee80211_local *local, struct sta_info *sta)
 335 {
 336         int i;
 337
 338         IWL_DEBUG_RATE("enter\n");
 339
 340         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 341          * the lowest or the highest rate.. Could consider using RSSI from
 342          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 343          * after assoc.. */
 344
 345         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 346                 if (sta->supp_rates & (1 << i)) {
 347                         sta->txrate = i;
 348                         break;
 349                 }
 350         }
 351
 352         sta->last_txrate = sta->txrate;
 353
 354         IWL_DEBUG_RATE("leave\n");
 355 }
 356
 357 static void *rs_alloc(struct ieee80211_local *local)
 358 {
 359         return local->hw.priv;
 360 }
 361
 362 /* rate scale requires free function to be implmented */
 363 static void rs_free(void *priv)
 364 {
 365         return;
 366 }
 367 static void rs_clear(void *priv)
 368 {
 369         return;
 370 }
 371
 372
 373 static void *rs_alloc_sta(void *priv, gfp_t gfp)
 374 {
 375         struct iwl_rate_scale_priv *rs_priv;
 376         int i;
 377
 378         IWL_DEBUG_RATE("enter\n");
 379
 380         rs_priv = kzalloc(sizeof(struct iwl_rate_scale_priv), gfp);
 381         if (!rs_priv) {
 382                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 383                 return NULL;
 384         }
 385
 386         spin_lock_init(&rs_priv->lock);
 387
 388         rs_priv->start_rate = IWL_RATE_INVALID;
 389
 390         /* default to just 802.11b */
 391         rs_priv->expected_tpt = iwl_expected_tpt_b;
 392
 393         rs_priv->last_partial_flush = jiffies;
 394         rs_priv->last_flush = jiffies;
 395         rs_priv->flush_time = IWL_RATE_FLUSH;
 396         rs_priv->last_tx_packets = 0;
 397         rs_priv->ibss_sta_added = 0;
 398
 399         init_timer(&rs_priv->rate_scale_flush);
 400         rs_priv->rate_scale_flush.data = (unsigned long)rs_priv;
 401         rs_priv->rate_scale_flush.function = &iwl_bg_rate_scale_flush;
 402
 403         for (i = 0; i < IWL_RATE_COUNT; i++)
 404                 iwl_clear_window(&rs_priv->win[i]);
 405
 406         IWL_DEBUG_RATE("leave\n");
 407
 408         return rs_priv;
 409 }
 410
 411 static void rs_free_sta(void *priv, void *priv_sta)
 412 {
 413         struct iwl_rate_scale_priv *rs_priv = priv_sta;
 414
 415         IWL_DEBUG_RATE("enter\n");
 416         del_timer_sync(&rs_priv->rate_scale_flush);
 417         kfree(rs_priv);
 418         IWL_DEBUG_RATE("leave\n");
 419 }
 420
 421 /**
 422  * rs_tx_status - Update rate control values based on Tx results
 423  *
 424  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 425  * the hardware for each rate.
 426  */
 427 static void rs_tx_status(void *priv_rate,
 428                          struct net_device *dev,
 429                          struct sk_buff *skb,
 430                          struct ieee80211_tx_status *tx_resp)
 431 {
 432         u8 retries, current_count;
 433         int scale_rate_index, first_index, last_index;
 434         unsigned long flags;
 435         struct sta_info *sta;
 436         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 437         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 438         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 439         struct iwl_rate_scale_priv *rs_priv;
 440
 441         IWL_DEBUG_RATE("enter\n");
 442
 443         retries = tx_resp->retry_count;
 444
 445         first_index = tx_resp->control.tx_rate;
 446         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 447                 IWL_DEBUG_RATE("leave: Rate out of bounds: %0x for %d\n",
 448                                tx_resp->control.tx_rate, first_index);
 449                 return;
 450         }
 451
 452         sta = sta_info_get(local, hdr->addr1);
 453         if (!sta || !sta->rate_ctrl_priv) {
 454                 if (sta)
 455                         sta_info_put(sta);
 456                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 457                 return;
 458         }
 459
 460         rs_priv = (void *)sta->rate_ctrl_priv;
 461
 462         rs_priv->tx_packets++;
 463
 464         scale_rate_index = first_index;
 465         last_index = first_index;
 466
 467         /*
 468          * Update the window for each rate.  We determine which rates
 469          * were Tx'd based on the total number of retries vs. the number
 470          * of retries configured for each rate -- currently set to the
 471          * priv value 'retry_rate' vs. rate specific
 472          *
 473          * On exit from this while loop last_index indicates the rate
 474          * at which the frame was finally transmitted (or failed if no
 475          * ACK)
 476          */
 477         while (retries > 0) {
 478                 if (retries < priv->retry_rate) {
 479                         current_count = retries;
 480                         last_index = scale_rate_index;
 481                 } else {
 482                         current_count = priv->retry_rate;
 483                         last_index = iwl_get_prev_ieee_rate(scale_rate_index);
 484                 }
 485
 486                 /* Update this rate accounting for as many retries
 487                  * as was used for it (per current_count) */
 488                 iwl_collect_tx_data(rs_priv,
 489                                     &rs_priv->win[scale_rate_index],
 490                                     0, current_count);
 491                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 492                                scale_rate_index, current_count);
 493
 494                 retries -= current_count;
 495
 496                 if (retries)
 497                         scale_rate_index =
 498                             iwl_get_prev_ieee_rate(scale_rate_index);
 499         }
 500
 501         /* Update the last index window with success/failure based on ACK */
 502         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 503                        last_index,
 504                        (tx_resp->flags & IEEE80211_TX_STATUS_ACK) ?
 505                        "success" : "failure");
 506         iwl_collect_tx_data(rs_priv,
 507                             &rs_priv->win[last_index],
 508                             tx_resp->flags & IEEE80211_TX_STATUS_ACK, 1);
 509
 510         /* We updated the rate scale window -- if its been more than
 511          * flush_time since the last run, schedule the flush
 512          * again */
 513         spin_lock_irqsave(&rs_priv->lock, flags);
 514
 515         if (!rs_priv->flush_pending &&
 516             time_after(jiffies, rs_priv->last_partial_flush +
 517                        rs_priv->flush_time)) {
 518
 519                 rs_priv->flush_pending = 1;
 520                 mod_timer(&rs_priv->rate_scale_flush,
 521                           jiffies + rs_priv->flush_time);
 522         }
 523
 524         spin_unlock_irqrestore(&rs_priv->lock, flags);
 525
 526         sta_info_put(sta);
 527
 528         IWL_DEBUG_RATE("leave\n");
 529
 530         return;
 531 }
 532
 533 static struct ieee80211_rate *iwl_get_lowest_rate(struct ieee80211_local
 534                                                   *local)
 535 {
 536         struct ieee80211_hw_mode *mode = local->oper_hw_mode;
 537         int i;
 538
 539         for (i = 0; i < mode->num_rates; i++) {
 540                 struct ieee80211_rate *rate = &mode->rates[i];
 541
 542                 if (rate->flags & IEEE80211_RATE_SUPPORTED)
 543                         return rate;
 544         }
 545
 546         return &mode->rates[0];
 547 }
 548
 549 static u16 iwl_get_adjacent_rate(struct iwl_rate_scale_priv *rs_priv,
 550                                  u8 index, u16 rate_mask, int phymode)
 551 {
 552         u8 high = IWL_RATE_INVALID;
 553         u8 low = IWL_RATE_INVALID;
 554
 555         /* 802.11A walks to the next literal adjascent rate in
 556          * the rate table */
 557         if (unlikely(phymode == MODE_IEEE80211A)) {
 558                 int i;
 559                 u32 mask;
 560
 561                 /* Find the previous rate that is in the rate mask */
 562                 i = index - 1;
 563                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 564                         if (rate_mask & mask) {
 565                                 low = i;
 566                                 break;
 567                         }
 568                 }
 569
 570                 /* Find the next rate that is in the rate mask */
 571                 i = index + 1;
 572                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 573                         if (rate_mask & mask) {
 574                                 high = i;
 575                                 break;
 576                         }
 577                 }
 578
 579                 return (high << 8) | low;
 580         }
 581
 582         low = index;
 583         while (low != IWL_RATE_INVALID) {
 584                 if (rs_priv->tgg)
 585                         low = iwl_rates[low].prev_rs_tgg;
 586                 else
 587                         low = iwl_rates[low].prev_rs;
 588                 if (low == IWL_RATE_INVALID)
 589                         break;
 590                 if (rate_mask & (1 << low))
 591                         break;
 592                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 593         }
 594
 595         high = index;
 596         while (high != IWL_RATE_INVALID) {
 597                 if (rs_priv->tgg)
 598                         high = iwl_rates[high].next_rs_tgg;
 599                 else
 600                         high = iwl_rates[high].next_rs;
 601                 if (high == IWL_RATE_INVALID)
 602                         break;
 603                 if (rate_mask & (1 << high))
 604                         break;
 605                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 606         }
 607
 608         return (high << 8) | low;
 609 }
 610
 611 /**
 612  * rs_get_rate - find the rate for the requested packet
 613  *
 614  * Returns the ieee80211_rate structure allocated by the driver.
 615  *
 616  * The rate control algorithm has no internal mapping between hw_mode's
 617  * rate ordering and the rate ordering used by the rate control algorithm.
 618  *
 619  * The rate control algorithm uses a single table of rates that goes across
 620  * the entire A/B/G spectrum vs. being limited to just one particular
 621  * hw_mode.
 622  *
 623  * As such, we can't convert the index obtained below into the hw_mode's
 624  * rate table and must reference the driver allocated rate table
 625  *
 626  */
 627 static struct ieee80211_rate *rs_get_rate(void *priv_rate,
 628                                           struct net_device *dev,
 629                                           struct sk_buff *skb,
 630                                           struct rate_control_extra *extra)
 631 {
 632         u8 low = IWL_RATE_INVALID;
 633         u8 high = IWL_RATE_INVALID;
 634         u16 high_low;
 635         int index;
 636         struct iwl_rate_scale_priv *rs_priv;
 637         struct iwl_rate_scale_data *window = NULL;
 638         int current_tpt = IWL_INVALID_VALUE;
 639         int low_tpt = IWL_INVALID_VALUE;
 640         int high_tpt = IWL_INVALID_VALUE;
 641         u32 fail_count;
 642         s8 scale_action = 0;
 643         unsigned long flags;
 644         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 645         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 646         struct sta_info *sta;
 647         u16 fc, rate_mask;
 648         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 649
 650         IWL_DEBUG_RATE("enter\n");
 651
 652         memset(extra, 0, sizeof(*extra));
 653
 654         fc = le16_to_cpu(hdr->frame_control);
 655         if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
 656             (is_multicast_ether_addr(hdr->addr1))) {
 657                 /* Send management frames and broadcast/multicast data using
 658                  * lowest rate. */
 659                 /* TODO: this could probably be improved.. */
 660                 IWL_DEBUG_RATE("leave: lowest rate (not data or is "
 661                                "multicast)\n");
 662
 663                 return iwl_get_lowest_rate(local);
 664         }
 665
 666         sta = sta_info_get(local, hdr->addr1);
 667         if (!sta || !sta->rate_ctrl_priv) {
 668                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 669                 if (sta)
 670                         sta_info_put(sta);
 671                 return NULL;
 672         }
 673
 674         rate_mask = sta->supp_rates;
 675         index = min(sta->txrate & 0xffff, IWL_RATE_COUNT - 1);
 676
 677         rs_priv = (void *)sta->rate_ctrl_priv;
 678
 679         if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 680             !rs_priv->ibss_sta_added) {
 681                 u8 sta_id = iwl_hw_find_station(priv, hdr->addr1);
 682
 683                 if (sta_id == IWL_INVALID_STATION) {
 684                         IWL_DEBUG_RATE("LQ: ADD station " MAC_FMT "\n",
 685                                         MAC_ARG(hdr->addr1));
 686                         sta_id = iwl_add_station(priv,
 687                                     hdr->addr1, 0, CMD_ASYNC);
 688                 }
 689                 if (sta_id != IWL_INVALID_STATION)
 690                         rs_priv->ibss_sta_added = 1;
 691         }
 692
 693         spin_lock_irqsave(&rs_priv->lock, flags);
 694
 695         if (rs_priv->start_rate != IWL_RATE_INVALID) {
 696                 index = rs_priv->start_rate;
 697                 rs_priv->start_rate = IWL_RATE_INVALID;
 698         }
 699
 700         window = &(rs_priv->win[index]);
 701
 702         fail_count = window->counter - window->success_counter;
 703
 704         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 705              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 706                 window->average_tpt = IWL_INVALID_VALUE;
 707                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 708
 709                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 710                                "counter: %d, success_counter: %d, "
 711                                "expected_tpt is %sNULL\n",
 712                                index,
 713                                window->counter,
 714                                window->success_counter,
 715                                rs_priv->expected_tpt ? "not " : "");
 716                 goto out;
 717
 718         }
 719
 720         window->average_tpt = ((window->success_ratio *
 721                                 rs_priv->expected_tpt[index] + 64) / 128);
 722         current_tpt = window->average_tpt;
 723
 724         high_low = iwl_get_adjacent_rate(rs_priv, index, rate_mask,
 725                                          local->hw.conf.phymode);
 726         low = high_low & 0xff;
 727         high = (high_low >> 8) & 0xff;
 728
 729         if (low != IWL_RATE_INVALID)
 730                 low_tpt = rs_priv->win[low].average_tpt;
 731
 732         if (high != IWL_RATE_INVALID)
 733                 high_tpt = rs_priv->win[high].average_tpt;
 734
 735         spin_unlock_irqrestore(&rs_priv->lock, flags);
 736
 737         scale_action = 1;
 738
 739         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 740                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 741                 scale_action = -1;
 742         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 743                    (high_tpt == IWL_INVALID_VALUE))
 744                 scale_action = 1;
 745         else if ((low_tpt != IWL_INVALID_VALUE) &&
 746                    (high_tpt != IWL_INVALID_VALUE)
 747                    && (low_tpt < current_tpt)
 748                    && (high_tpt < current_tpt)) {
 749                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 750                                "current_tpt [%d]\n",
 751                                low_tpt, high_tpt, current_tpt);
 752                 scale_action = 0;
 753         } else {
 754                 if (high_tpt != IWL_INVALID_VALUE) {
 755                         if (high_tpt > current_tpt)
 756                                 scale_action = 1;
 757                         else {
 758                                 IWL_DEBUG_RATE
 759                                     ("decrease rate because of high tpt\n");
 760                                 scale_action = -1;
 761                         }
 762                 } else if (low_tpt != IWL_INVALID_VALUE) {
 763                         if (low_tpt > current_tpt) {
 764                                 IWL_DEBUG_RATE
 765                                     ("decrease rate because of low tpt\n");
 766                                 scale_action = -1;
 767                         } else
 768                                 scale_action = 1;
 769                 }
 770         }
 771
 772         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 773             (current_tpt > window->average_tpt)) {
 774                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 775                                "current_tpt [%d] > average_tpt [%d]\n",
 776                                window->success_ratio,
 777                                current_tpt, window->average_tpt);
 778                 scale_action = 0;
 779         }
 780
 781         switch (scale_action) {
 782         case -1:
 783                 if (low != IWL_RATE_INVALID)
 784                         index = low;
 785                 break;
 786
 787         case 1:
 788                 if (high != IWL_RATE_INVALID)
 789                         index = high;
 790
 791                 break;
 792
 793         case 0:
 794         default:
 795                 break;
 796         }
 797
 798         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 799                        index, scale_action, low, high);
 800
 801  out:
 802
 803         sta->last_txrate = index;
 804         sta->txrate = sta->last_txrate;
 805         sta_info_put(sta);
 806
 807         IWL_DEBUG_RATE("leave: %d\n", index);
 808
 809         return &priv->ieee_rates[index];
 810 }
 811
 812 static struct rate_control_ops rs_ops = {
 813         .module = NULL,
 814         .name = RS_NAME,
 815         .tx_status = rs_tx_status,
 816         .get_rate = rs_get_rate,
 817         .rate_init = rs_rate_init,
 818         .clear = rs_clear,
 819         .alloc = rs_alloc,
 820         .free = rs_free,
 821         .alloc_sta = rs_alloc_sta,
 822         .free_sta = rs_free_sta,
 823 };
 824
 825 int iwl_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 826 {
 827         struct ieee80211_local *local = hw_to_local(hw);
 828         struct iwl_priv *priv = hw->priv;
 829         struct iwl_rate_scale_priv *rs_priv;
 830         struct sta_info *sta;
 831         unsigned long flags;
 832         int count = 0, i;
 833         u32 samples = 0, success = 0, good = 0;
 834         unsigned long now = jiffies;
 835         u32 max_time = 0;
 836
 837         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 838         if (!sta || !sta->rate_ctrl_priv) {
 839                 if (sta) {
 840                         sta_info_put(sta);
 841                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 842                 } else
 843                         IWL_DEBUG_RATE("leave - no station!\n");
 844                 return sprintf(buf, "station %d not found\n", sta_id);
 845         }
 846
 847         rs_priv = (void *)sta->rate_ctrl_priv;
 848         spin_lock_irqsave(&rs_priv->lock, flags);
 849         i = IWL_RATE_54M_INDEX;
 850         while (1) {
 851                 u64 mask;
 852                 int j;
 853
 854                 count +=
 855                     sprintf(&buf[count], " %2dMbs: ", iwl_rates[i].ieee / 2);
 856
 857                 mask = (1ULL << (IWL_RATE_MAX_WINDOW - 1));
 858                 for (j = 0; j < IWL_RATE_MAX_WINDOW; j++, mask >>= 1)
 859                         buf[count++] =
 860                             (rs_priv->win[i].data & mask) ? '1' : '0';
 861
 862                 samples += rs_priv->win[i].counter;
 863                 good += rs_priv->win[i].success_counter;
 864                 success += rs_priv->win[i].success_counter * iwl_rates[i].ieee;
 865
 866                 if (rs_priv->win[i].stamp) {
 867                         int delta =
 868                             jiffies_to_msecs(now - rs_priv->win[i].stamp);
 869
 870                         if (delta > max_time)
 871                                 max_time = delta;
 872
 873                         count += sprintf(&buf[count], "%5dms\n", delta);
 874                 } else
 875                         buf[count++] = '\n';
 876
 877                 j = iwl_get_prev_ieee_rate(i);
 878                 if (j == i)
 879                         break;
 880                 i = j;
 881         }
 882         spin_unlock_irqrestore(&rs_priv->lock, flags);
 883         sta_info_put(sta);
 884
 885         /* Display the average rate of all samples taken.
 886          *
 887          * NOTE:  We multiple # of samples by 2 since the IEEE measurement
 888          * added from iwl_rates is actually 2X the rate */
 889         if (samples)
 890                 count += sprintf(
 891                         &buf[count],
 892                         "\nAverage rate is %3d.%02dMbs over last %4dms\n"
 893                         "%3d%% success (%d good packets over %d tries)\n",
 894                         success / (2 * samples), (success * 5 / samples) % 10,
 895                         max_time, good * 100 / samples, good, samples);
 896         else
 897                 count += sprintf(&buf[count], "\nAverage rate: 0Mbs\n");
 898
 899         return count;
 900 }
 901
 902 void iwl_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 903 {
 904         struct iwl_priv *priv = hw->priv;
 905         s32 rssi = 0;
 906         unsigned long flags;
 907         struct ieee80211_local *local = hw_to_local(hw);
 908         struct iwl_rate_scale_priv *rs_priv;
 909         struct sta_info *sta;
 910
 911         IWL_DEBUG_RATE("enter\n");
 912
 913         if (!local->rate_ctrl->ops->name ||
 914             strcmp(local->rate_ctrl->ops->name, RS_NAME)) {
 915                 IWL_WARNING("iwl-3945-rs not selected as rate control algo!\n");
 916                 IWL_DEBUG_RATE("leave - mac80211 picked the wrong RC algo.\n");
 917                 return;
 918         }
 919
 920         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 921         if (!sta || !sta->rate_ctrl_priv) {
 922                 if (sta)
 923                         sta_info_put(sta);
 924                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 925                 return;
 926         }
 927
 928         rs_priv = (void *)sta->rate_ctrl_priv;
 929
 930         spin_lock_irqsave(&rs_priv->lock, flags);
 931
 932         rs_priv->tgg = 0;
 933         switch (priv->phymode) {
 934         case MODE_IEEE80211G:
 935                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 936                         rs_priv->tgg = 1;
 937                         rs_priv->expected_tpt = iwl_expected_tpt_g_prot;
 938                 } else
 939                         rs_priv->expected_tpt = iwl_expected_tpt_g;
 940                 break;
 941
 942         case MODE_IEEE80211A:
 943                 rs_priv->expected_tpt = iwl_expected_tpt_a;
 944                 break;
 945
 946         default:
 947                 IWL_WARNING("Invalid phymode.  Defaulting to 802.11b\n");
 948         case MODE_IEEE80211B:
 949                 rs_priv->expected_tpt = iwl_expected_tpt_b;
 950                 break;
 951         }
 952
 953         sta_info_put(sta);
 954         spin_unlock_irqrestore(&rs_priv->lock, flags);
 955
 956         rssi = priv->last_rx_rssi;
 957         if (rssi == 0)
 958                 rssi = IWL_MIN_RSSI_VAL;
 959
 960         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 961
 962         rs_priv->start_rate = iwl_get_rate_index_by_rssi(rssi, priv->phymode);
 963
 964         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 965                        "%d (plcp 0x%x)\n", rssi, rs_priv->start_rate,
 966                        iwl_rates[rs_priv->start_rate].plcp);
 967 }
 968
 969 void iwl_rate_control_register(struct ieee80211_hw *hw)
 970 {
 971         ieee80211_rate_control_register(&rs_ops);
 972 }
 973
 974 void iwl_rate_control_unregister(struct ieee80211_hw *hw)
 975 {
 976         ieee80211_rate_control_unregister(&rs_ops);
 977 }
 978
 979