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00011 #include <linux/kernel.h>
00012 #include <linux/rtnetlink.h>
00013 #include <linux/slab.h>
00014 #include <linux/module.h>
00015 #include "rate.h"
00016 #include "ieee80211_i.h"
00017 #include "debugfs.h"
00018
00019 struct rate_control_alg {
00020 struct list_head list;
00021 struct rate_control_ops *ops;
00022 };
00023
00024 static LIST_HEAD(rate_ctrl_algs);
00025 static DEFINE_MUTEX(rate_ctrl_mutex);
00026
00027 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
00028 module_param(ieee80211_default_rc_algo, charp, 0644);
00029 MODULE_PARM_DESC(ieee80211_default_rc_algo,
00030 "Default rate control algorithm for mac80211 to use");
00031
00032 int ieee80211_rate_control_register(struct rate_control_ops *ops)
00033 {
00034 struct rate_control_alg *alg;
00035
00036 if (!ops->name)
00037 return -EINVAL;
00038
00039 mutex_lock(&rate_ctrl_mutex);
00040 list_for_each_entry(alg, &rate_ctrl_algs, list) {
00041 if (!strcmp(alg->ops->name, ops->name)) {
00042
00043 WARN_ON(1);
00044 mutex_unlock(&rate_ctrl_mutex);
00045 return -EALREADY;
00046 }
00047 }
00048
00049 alg = kzalloc(sizeof(*alg), GFP_KERNEL);
00050 if (alg == NULL) {
00051 mutex_unlock(&rate_ctrl_mutex);
00052 return -ENOMEM;
00053 }
00054 alg->ops = ops;
00055
00056 list_add_tail(&alg->list, &rate_ctrl_algs);
00057 mutex_unlock(&rate_ctrl_mutex);
00058
00059 return 0;
00060 }
00061 EXPORT_SYMBOL(ieee80211_rate_control_register);
00062
00063 void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
00064 {
00065 struct rate_control_alg *alg;
00066
00067 mutex_lock(&rate_ctrl_mutex);
00068 list_for_each_entry(alg, &rate_ctrl_algs, list) {
00069 if (alg->ops == ops) {
00070 list_del(&alg->list);
00071 kfree(alg);
00072 break;
00073 }
00074 }
00075 mutex_unlock(&rate_ctrl_mutex);
00076 }
00077 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
00078
00079 static struct rate_control_ops *
00080 ieee80211_try_rate_control_ops_get(const char *name)
00081 {
00082 struct rate_control_alg *alg;
00083 struct rate_control_ops *ops = NULL;
00084
00085 if (!name)
00086 return NULL;
00087
00088 mutex_lock(&rate_ctrl_mutex);
00089 list_for_each_entry(alg, &rate_ctrl_algs, list) {
00090 if (!strcmp(alg->ops->name, name))
00091 if (try_module_get(alg->ops->module)) {
00092 ops = alg->ops;
00093 break;
00094 }
00095 }
00096 mutex_unlock(&rate_ctrl_mutex);
00097 return ops;
00098 }
00099
00100
00101 static struct rate_control_ops *
00102 ieee80211_rate_control_ops_get(const char *name)
00103 {
00104 struct rate_control_ops *ops;
00105 const char *alg_name;
00106
00107 kparam_block_sysfs_write(ieee80211_default_rc_algo);
00108 if (!name)
00109 alg_name = ieee80211_default_rc_algo;
00110 else
00111 alg_name = name;
00112
00113 ops = ieee80211_try_rate_control_ops_get(alg_name);
00114 if (!ops) {
00115 request_module("rc80211_%s", alg_name);
00116 ops = ieee80211_try_rate_control_ops_get(alg_name);
00117 }
00118 if (!ops && name)
00119
00120 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
00121
00122
00123 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
00124 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
00125 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
00126
00127 return ops;
00128 }
00129
00130 static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
00131 {
00132 module_put(ops->module);
00133 }
00134
00135 #ifdef CONFIG_MAC80211_DEBUGFS
00136 static ssize_t rcname_read(struct file *file, char __user *userbuf,
00137 size_t count, loff_t *ppos)
00138 {
00139 struct rate_control_ref *ref = file->private_data;
00140 int len = strlen(ref->ops->name);
00141
00142 return simple_read_from_buffer(userbuf, count, ppos,
00143 ref->ops->name, len);
00144 }
00145
00146 static const struct file_operations rcname_ops = {
00147 .read = rcname_read,
00148 .open = simple_open,
00149 .llseek = default_llseek,
00150 };
00151 #endif
00152
00153 static struct rate_control_ref *rate_control_alloc(const char *name,
00154 struct ieee80211_local *local)
00155 {
00156 struct dentry *debugfsdir = NULL;
00157 struct rate_control_ref *ref;
00158
00159 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
00160 if (!ref)
00161 goto fail_ref;
00162 ref->local = local;
00163 ref->ops = ieee80211_rate_control_ops_get(name);
00164 if (!ref->ops)
00165 goto fail_ops;
00166
00167 #ifdef CONFIG_MAC80211_DEBUGFS
00168 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
00169 local->debugfs.rcdir = debugfsdir;
00170 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
00171 #endif
00172
00173 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
00174 if (!ref->priv)
00175 goto fail_priv;
00176 return ref;
00177
00178 fail_priv:
00179 ieee80211_rate_control_ops_put(ref->ops);
00180 fail_ops:
00181 kfree(ref);
00182 fail_ref:
00183 return NULL;
00184 }
00185
00186 static void rate_control_free(struct rate_control_ref *ctrl_ref)
00187 {
00188 ctrl_ref->ops->free(ctrl_ref->priv);
00189
00190 #ifdef CONFIG_MAC80211_DEBUGFS
00191 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
00192 ctrl_ref->local->debugfs.rcdir = NULL;
00193 #endif
00194
00195 ieee80211_rate_control_ops_put(ctrl_ref->ops);
00196 kfree(ctrl_ref);
00197 }
00198
00199 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
00200 {
00201 struct sk_buff *skb = txrc->skb;
00202 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
00203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
00204 __le16 fc;
00205
00206 fc = hdr->frame_control;
00207
00208 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
00209 IEEE80211_TX_CTL_USE_MINRATE)) ||
00210 !ieee80211_is_data(fc);
00211 }
00212
00213 static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
00214 struct ieee80211_supported_band *sband)
00215 {
00216 u8 i;
00217
00218 if (basic_rates == 0)
00219 return;
00220 if (*idx < 0)
00221 return;
00222 if (basic_rates & (1 << *idx))
00223 return;
00224
00225 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
00226 if (basic_rates & (1 << i)) {
00227 *idx = i;
00228 return;
00229 }
00230 }
00231
00232
00233 }
00234
00235 static inline s8
00236 rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
00237 struct ieee80211_sta *sta)
00238 {
00239 int i;
00240
00241 for (i = 0; i < sband->n_bitrates; i++) {
00242 struct ieee80211_rate *srate = &sband->bitrates[i];
00243 if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
00244 (srate->bitrate == 55) || (srate->bitrate == 110))
00245 continue;
00246
00247 if (rate_supported(sta, sband->band, i))
00248 return i;
00249 }
00250
00251
00252 return 0;
00253 }
00254
00255
00256 bool rate_control_send_low(struct ieee80211_sta *sta,
00257 void *priv_sta,
00258 struct ieee80211_tx_rate_control *txrc)
00259 {
00260 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
00261 struct ieee80211_supported_band *sband = txrc->sband;
00262 int mcast_rate;
00263
00264 if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
00265 if ((sband->band != IEEE80211_BAND_2GHZ) ||
00266 !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
00267 info->control.rates[0].idx =
00268 rate_lowest_index(txrc->sband, sta);
00269 else
00270 info->control.rates[0].idx =
00271 rate_lowest_non_cck_index(txrc->sband, sta);
00272 info->control.rates[0].count =
00273 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
00274 1 : txrc->hw->max_rate_tries;
00275 if (!sta && txrc->bss) {
00276 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
00277 if (mcast_rate > 0) {
00278 info->control.rates[0].idx = mcast_rate - 1;
00279 return true;
00280 }
00281
00282 rc_send_low_broadcast(&info->control.rates[0].idx,
00283 txrc->bss_conf->basic_rates,
00284 sband);
00285 }
00286 return true;
00287 }
00288 return false;
00289 }
00290 EXPORT_SYMBOL(rate_control_send_low);
00291
00292 static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
00293 int n_bitrates, u32 mask)
00294 {
00295 int j;
00296
00297
00298 for (j = rate->idx; j >= 0; j--) {
00299 if (mask & (1 << j)) {
00300
00301 rate->idx = j;
00302 return true;
00303 }
00304 }
00305
00306
00307 for (j = rate->idx + 1; j < n_bitrates; j++) {
00308 if (mask & (1 << j)) {
00309
00310 rate->idx = j;
00311 return true;
00312 }
00313 }
00314 return false;
00315 }
00316
00317 static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
00318 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
00319 {
00320 int i, j;
00321 int ridx, rbit;
00322
00323 ridx = rate->idx / 8;
00324 rbit = rate->idx % 8;
00325
00326
00327 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
00328 return false;
00329
00330
00331 for (i = ridx; i >= 0; i--) {
00332 for (j = rbit; j >= 0; j--)
00333 if (mcs_mask[i] & BIT(j)) {
00334 rate->idx = i * 8 + j;
00335 return true;
00336 }
00337 rbit = 7;
00338 }
00339
00340
00341 ridx = (rate->idx + 1) / 8;
00342 rbit = (rate->idx + 1) % 8;
00343
00344 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
00345 for (j = rbit; j < 8; j++)
00346 if (mcs_mask[i] & BIT(j)) {
00347 rate->idx = i * 8 + j;
00348 return true;
00349 }
00350 rbit = 0;
00351 }
00352 return false;
00353 }
00354
00355
00356
00357 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
00358 struct ieee80211_tx_rate_control *txrc,
00359 u32 mask,
00360 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
00361 {
00362 struct ieee80211_tx_rate alt_rate;
00363
00364
00365 if (rate->flags & IEEE80211_TX_RC_MCS) {
00366 if (rate_idx_match_mcs_mask(rate, mcs_mask))
00367 return;
00368
00369
00370 alt_rate.idx = 0;
00371
00372 alt_rate.flags = rate->flags &
00373 (IEEE80211_TX_RC_USE_RTS_CTS |
00374 IEEE80211_TX_RC_USE_CTS_PROTECT |
00375 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
00376 alt_rate.count = rate->count;
00377 if (rate_idx_match_legacy_mask(&alt_rate,
00378 txrc->sband->n_bitrates,
00379 mask)) {
00380 *rate = alt_rate;
00381 return;
00382 }
00383 } else {
00384 struct sk_buff *skb = txrc->skb;
00385 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
00386 __le16 fc;
00387
00388
00389 if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
00390 mask))
00391 return;
00392
00393
00394 if (txrc->bss_conf->channel_type == NL80211_CHAN_NO_HT)
00395 return;
00396
00397 fc = hdr->frame_control;
00398 if (!ieee80211_is_data(fc))
00399 return;
00400
00401 alt_rate.idx = 0;
00402
00403 alt_rate.flags = rate->flags &
00404 (IEEE80211_TX_RC_USE_RTS_CTS |
00405 IEEE80211_TX_RC_USE_CTS_PROTECT |
00406 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
00407 alt_rate.count = rate->count;
00408
00409 alt_rate.flags |= IEEE80211_TX_RC_MCS;
00410
00411 if ((txrc->bss_conf->channel_type == NL80211_CHAN_HT40MINUS) ||
00412 (txrc->bss_conf->channel_type == NL80211_CHAN_HT40PLUS))
00413 alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
00414
00415 if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
00416 *rate = alt_rate;
00417 return;
00418 }
00419 }
00420
00421
00422
00423
00424
00425
00426
00427
00428 }
00429
00430 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
00431 struct sta_info *sta,
00432 struct ieee80211_tx_rate_control *txrc)
00433 {
00434 struct rate_control_ref *ref = sdata->local->rate_ctrl;
00435 void *priv_sta = NULL;
00436 struct ieee80211_sta *ista = NULL;
00437 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
00438 int i;
00439 u32 mask;
00440 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
00441
00442 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
00443 ista = &sta->sta;
00444 priv_sta = sta->rate_ctrl_priv;
00445 }
00446
00447 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
00448 info->control.rates[i].idx = -1;
00449 info->control.rates[i].flags = 0;
00450 info->control.rates[i].count = 0;
00451 }
00452
00453 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
00454 return;
00455
00456 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
00457
00458
00459
00460
00461
00462
00463 mask = sdata->rc_rateidx_mask[info->band];
00464 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
00465 sizeof(mcs_mask));
00466 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
00467 if (sta) {
00468
00469 mask &= sta->sta.supp_rates[info->band];
00470 for (i = 0; i < sizeof(mcs_mask); i++)
00471 mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
00472 }
00473
00474
00475
00476
00477
00478 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
00479
00480 if (info->control.rates[i].idx < 0)
00481 break;
00482 rate_idx_match_mask(&info->control.rates[i], txrc,
00483 mask, mcs_mask);
00484 }
00485 }
00486
00487 BUG_ON(info->control.rates[0].idx < 0);
00488 }
00489
00490 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
00491 const char *name)
00492 {
00493 struct rate_control_ref *ref;
00494
00495 ASSERT_RTNL();
00496
00497 if (local->open_count)
00498 return -EBUSY;
00499
00500 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
00501 if (WARN_ON(!local->ops->set_rts_threshold))
00502 return -EINVAL;
00503 return 0;
00504 }
00505
00506 ref = rate_control_alloc(name, local);
00507 if (!ref) {
00508 wiphy_warn(local->hw.wiphy,
00509 "Failed to select rate control algorithm\n");
00510 return -ENOENT;
00511 }
00512
00513 WARN_ON(local->rate_ctrl);
00514 local->rate_ctrl = ref;
00515
00516 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
00517 ref->ops->name);
00518
00519 return 0;
00520 }
00521
00522 void rate_control_deinitialize(struct ieee80211_local *local)
00523 {
00524 struct rate_control_ref *ref;
00525
00526 ref = local->rate_ctrl;
00527
00528 if (!ref)
00529 return;
00530
00531 local->rate_ctrl = NULL;
00532 rate_control_free(ref);
00533 }
00534