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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 = mac80211_open_file_generic,
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 kref_init(&ref->kref);
00163 ref->local = local;
00164 ref->ops = ieee80211_rate_control_ops_get(name);
00165 if (!ref->ops)
00166 goto fail_ops;
00167
00168 #ifdef CONFIG_MAC80211_DEBUGFS
00169 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
00170 local->debugfs.rcdir = debugfsdir;
00171 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
00172 #endif
00173
00174 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
00175 if (!ref->priv)
00176 goto fail_priv;
00177 return ref;
00178
00179 fail_priv:
00180 ieee80211_rate_control_ops_put(ref->ops);
00181 fail_ops:
00182 kfree(ref);
00183 fail_ref:
00184 return NULL;
00185 }
00186
00187 static void rate_control_release(struct kref *kref)
00188 {
00189 struct rate_control_ref *ctrl_ref;
00190
00191 ctrl_ref = container_of(kref, struct rate_control_ref, kref);
00192 ctrl_ref->ops->free(ctrl_ref->priv);
00193
00194 #ifdef CONFIG_MAC80211_DEBUGFS
00195 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
00196 ctrl_ref->local->debugfs.rcdir = NULL;
00197 #endif
00198
00199 ieee80211_rate_control_ops_put(ctrl_ref->ops);
00200 kfree(ctrl_ref);
00201 }
00202
00203 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
00204 {
00205 struct sk_buff *skb = txrc->skb;
00206 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
00207 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
00208 __le16 fc;
00209
00210 fc = hdr->frame_control;
00211
00212 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
00213 IEEE80211_TX_CTL_USE_MINRATE)) ||
00214 !ieee80211_is_data(fc);
00215 }
00216
00217 static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
00218 struct ieee80211_supported_band *sband)
00219 {
00220 u8 i;
00221
00222 if (basic_rates == 0)
00223 return;
00224 if (*idx < 0)
00225 return;
00226 if (basic_rates & (1 << *idx))
00227 return;
00228
00229 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
00230 if (basic_rates & (1 << i)) {
00231 *idx = i;
00232 return;
00233 }
00234 }
00235
00236
00237 }
00238
00239 static inline s8
00240 rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
00241 struct ieee80211_sta *sta)
00242 {
00243 int i;
00244
00245 for (i = 0; i < sband->n_bitrates; i++) {
00246 struct ieee80211_rate *srate = &sband->bitrates[i];
00247 if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
00248 (srate->bitrate == 55) || (srate->bitrate == 110))
00249 continue;
00250
00251 if (rate_supported(sta, sband->band, i))
00252 return i;
00253 }
00254
00255
00256 return 0;
00257 }
00258
00259
00260 bool rate_control_send_low(struct ieee80211_sta *sta,
00261 void *priv_sta,
00262 struct ieee80211_tx_rate_control *txrc)
00263 {
00264 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
00265 struct ieee80211_supported_band *sband = txrc->sband;
00266 int mcast_rate;
00267
00268 if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
00269 if ((sband->band != IEEE80211_BAND_2GHZ) ||
00270 !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
00271 info->control.rates[0].idx =
00272 rate_lowest_index(txrc->sband, sta);
00273 else
00274 info->control.rates[0].idx =
00275 rate_lowest_non_cck_index(txrc->sband, sta);
00276 info->control.rates[0].count =
00277 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
00278 1 : txrc->hw->max_rate_tries;
00279 if (!sta && txrc->bss) {
00280 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
00281 if (mcast_rate > 0) {
00282 info->control.rates[0].idx = mcast_rate - 1;
00283 return true;
00284 }
00285
00286 rc_send_low_broadcast(&info->control.rates[0].idx,
00287 txrc->bss_conf->basic_rates,
00288 sband);
00289 }
00290 return true;
00291 }
00292 return false;
00293 }
00294 EXPORT_SYMBOL(rate_control_send_low);
00295
00296 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
00297 int n_bitrates, u32 mask)
00298 {
00299 int j;
00300
00301
00302 for (j = rate->idx; j >= 0; j--) {
00303 if (mask & (1 << j)) {
00304
00305 rate->idx = j;
00306 return;
00307 }
00308 }
00309
00310
00311 for (j = rate->idx + 1; j < n_bitrates; j++) {
00312 if (mask & (1 << j)) {
00313
00314 rate->idx = j;
00315 return;
00316 }
00317 }
00318
00319
00320
00321
00322
00323
00324
00325
00326 }
00327
00328 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
00329 struct sta_info *sta,
00330 struct ieee80211_tx_rate_control *txrc)
00331 {
00332 struct rate_control_ref *ref = sdata->local->rate_ctrl;
00333 void *priv_sta = NULL;
00334 struct ieee80211_sta *ista = NULL;
00335 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
00336 int i;
00337 u32 mask;
00338
00339 if (sta) {
00340 ista = &sta->sta;
00341 priv_sta = sta->rate_ctrl_priv;
00342 }
00343
00344 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
00345 info->control.rates[i].idx = -1;
00346 info->control.rates[i].flags = 0;
00347 info->control.rates[i].count = 0;
00348 }
00349
00350 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
00351 return;
00352
00353 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
00354
00355
00356
00357
00358
00359
00360 mask = sdata->rc_rateidx_mask[info->band];
00361 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
00362 if (sta) {
00363
00364 mask &= sta->sta.supp_rates[info->band];
00365 }
00366
00367
00368
00369
00370
00371 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
00372
00373 if (info->control.rates[i].idx < 0)
00374 break;
00375
00376 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
00377 continue;
00378 rate_idx_match_mask(&info->control.rates[i],
00379 txrc->sband->n_bitrates, mask);
00380 }
00381 }
00382
00383 BUG_ON(info->control.rates[0].idx < 0);
00384 }
00385
00386 struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
00387 {
00388 kref_get(&ref->kref);
00389 return ref;
00390 }
00391
00392 void rate_control_put(struct rate_control_ref *ref)
00393 {
00394 kref_put(&ref->kref, rate_control_release);
00395 }
00396
00397 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
00398 const char *name)
00399 {
00400 struct rate_control_ref *ref, *old;
00401
00402 ASSERT_RTNL();
00403
00404 if (local->open_count)
00405 return -EBUSY;
00406
00407 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
00408 if (WARN_ON(!local->ops->set_rts_threshold))
00409 return -EINVAL;
00410 return 0;
00411 }
00412
00413 ref = rate_control_alloc(name, local);
00414 if (!ref) {
00415 wiphy_warn(local->hw.wiphy,
00416 "Failed to select rate control algorithm\n");
00417 return -ENOENT;
00418 }
00419
00420 old = local->rate_ctrl;
00421 local->rate_ctrl = ref;
00422 if (old) {
00423 rate_control_put(old);
00424 sta_info_flush(local, NULL);
00425 }
00426
00427 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
00428 ref->ops->name);
00429
00430 return 0;
00431 }
00432
00433 void rate_control_deinitialize(struct ieee80211_local *local)
00434 {
00435 struct rate_control_ref *ref;
00436
00437 ref = local->rate_ctrl;
00438
00439 if (!ref)
00440 return;
00441
00442 local->rate_ctrl = NULL;
00443 rate_control_put(ref);
00444 }
00445