1 /* 2 * Copyright (c) 2014, Lorenzo Bianconi <lorenzo.bianconi83@gmail.com> 3 * 4 * Permission to use, copy, modify, and/or distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #include "ath9k.h" 18 #include "hw.h" 19 #include "dynack.h" 20 21 #define COMPUTE_TO (5 * HZ) 22 #define LATEACK_DELAY (10 * HZ) 23 #define LATEACK_TO 256 24 #define MAX_DELAY 300 25 #define EWMA_LEVEL 96 26 #define EWMA_DIV 128 27 28 /** 29 * ath_dynack_ewma - EWMA (Exponentially Weighted Moving Average) calculation 30 * 31 */ 32 static inline u32 ath_dynack_ewma(u32 old, u32 new) 33 { 34 return (new * (EWMA_DIV - EWMA_LEVEL) + old * EWMA_LEVEL) / EWMA_DIV; 35 } 36 37 /** 38 * ath_dynack_get_sifs - get sifs time based on phy used 39 * @ah: ath hw 40 * @phy: phy used 41 * 42 */ 43 static inline u32 ath_dynack_get_sifs(struct ath_hw *ah, int phy) 44 { 45 u32 sifs = CCK_SIFS_TIME; 46 47 if (phy == WLAN_RC_PHY_OFDM) { 48 if (IS_CHAN_QUARTER_RATE(ah->curchan)) 49 sifs = OFDM_SIFS_TIME_QUARTER; 50 else if (IS_CHAN_HALF_RATE(ah->curchan)) 51 sifs = OFDM_SIFS_TIME_HALF; 52 else 53 sifs = OFDM_SIFS_TIME; 54 } 55 return sifs; 56 } 57 58 /** 59 * ath_dynack_bssidmask - filter out ACK frames based on BSSID mask 60 * @ah: ath hw 61 * @mac: receiver address 62 */ 63 static inline bool ath_dynack_bssidmask(struct ath_hw *ah, const u8 *mac) 64 { 65 int i; 66 struct ath_common *common = ath9k_hw_common(ah); 67 68 for (i = 0; i < ETH_ALEN; i++) { 69 if ((common->macaddr[i] & common->bssidmask[i]) != 70 (mac[i] & common->bssidmask[i])) 71 return false; 72 } 73 74 return true; 75 } 76 77 /** 78 * ath_dynack_compute_ackto - compute ACK timeout as the maximum STA timeout 79 * @ah: ath hw 80 * 81 * should be called while holding qlock 82 */ 83 static void ath_dynack_compute_ackto(struct ath_hw *ah) 84 { 85 struct ath_node *an; 86 u32 to = 0; 87 struct ath_dynack *da = &ah->dynack; 88 struct ath_common *common = ath9k_hw_common(ah); 89 90 list_for_each_entry(an, &da->nodes, list) 91 if (an->ackto > to) 92 to = an->ackto; 93 94 if (to && da->ackto != to) { 95 u32 slottime; 96 97 slottime = (to - 3) / 2; 98 da->ackto = to; 99 ath_dbg(common, DYNACK, "ACK timeout %u slottime %u\n", 100 da->ackto, slottime); 101 ath9k_hw_setslottime(ah, slottime); 102 ath9k_hw_set_ack_timeout(ah, da->ackto); 103 ath9k_hw_set_cts_timeout(ah, da->ackto); 104 } 105 } 106 107 /** 108 * ath_dynack_compute_to - compute STA ACK timeout 109 * @ah: ath hw 110 * 111 * should be called while holding qlock 112 */ 113 static void ath_dynack_compute_to(struct ath_hw *ah) 114 { 115 u32 ackto, ack_ts; 116 u8 *dst, *src; 117 struct ieee80211_sta *sta; 118 struct ath_node *an; 119 struct ts_info *st_ts; 120 struct ath_dynack *da = &ah->dynack; 121 122 rcu_read_lock(); 123 124 while (da->st_rbf.h_rb != da->st_rbf.t_rb && 125 da->ack_rbf.h_rb != da->ack_rbf.t_rb) { 126 ack_ts = da->ack_rbf.tstamp[da->ack_rbf.h_rb]; 127 st_ts = &da->st_rbf.ts[da->st_rbf.h_rb]; 128 dst = da->st_rbf.addr[da->st_rbf.h_rb].h_dest; 129 src = da->st_rbf.addr[da->st_rbf.h_rb].h_src; 130 131 ath_dbg(ath9k_hw_common(ah), DYNACK, 132 "ack_ts %u st_ts %u st_dur %u [%u-%u]\n", 133 ack_ts, st_ts->tstamp, st_ts->dur, 134 da->ack_rbf.h_rb, da->st_rbf.h_rb); 135 136 if (ack_ts > st_ts->tstamp + st_ts->dur) { 137 ackto = ack_ts - st_ts->tstamp - st_ts->dur; 138 139 if (ackto < MAX_DELAY) { 140 sta = ieee80211_find_sta_by_ifaddr(ah->hw, dst, 141 src); 142 if (sta) { 143 an = (struct ath_node *)sta->drv_priv; 144 an->ackto = ath_dynack_ewma(an->ackto, 145 ackto); 146 ath_dbg(ath9k_hw_common(ah), DYNACK, 147 "%pM to %u\n", dst, an->ackto); 148 if (time_is_before_jiffies(da->lto)) { 149 ath_dynack_compute_ackto(ah); 150 da->lto = jiffies + COMPUTE_TO; 151 } 152 } 153 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF); 154 } 155 INCR(da->st_rbf.h_rb, ATH_DYN_BUF); 156 } else { 157 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF); 158 } 159 } 160 161 rcu_read_unlock(); 162 } 163 164 /** 165 * ath_dynack_sample_tx_ts - status timestamp sampling method 166 * @ah: ath hw 167 * @skb: socket buffer 168 * @ts: tx status info 169 * 170 */ 171 void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb, 172 struct ath_tx_status *ts) 173 { 174 u8 ridx; 175 struct ieee80211_hdr *hdr; 176 struct ath_dynack *da = &ah->dynack; 177 struct ath_common *common = ath9k_hw_common(ah); 178 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 179 180 if ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !da->enabled) 181 return; 182 183 spin_lock_bh(&da->qlock); 184 185 hdr = (struct ieee80211_hdr *)skb->data; 186 187 /* late ACK */ 188 if (ts->ts_status & ATH9K_TXERR_XRETRY) { 189 if (ieee80211_is_assoc_req(hdr->frame_control) || 190 ieee80211_is_assoc_resp(hdr->frame_control)) { 191 ath_dbg(common, DYNACK, "late ack\n"); 192 ath9k_hw_setslottime(ah, (LATEACK_TO - 3) / 2); 193 ath9k_hw_set_ack_timeout(ah, LATEACK_TO); 194 ath9k_hw_set_cts_timeout(ah, LATEACK_TO); 195 da->lto = jiffies + LATEACK_DELAY; 196 } 197 198 spin_unlock_bh(&da->qlock); 199 return; 200 } 201 202 ridx = ts->ts_rateindex; 203 204 da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp; 205 da->st_rbf.ts[da->st_rbf.t_rb].dur = ts->duration; 206 ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1); 207 ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2); 208 209 if (!(info->status.rates[ridx].flags & IEEE80211_TX_RC_MCS)) { 210 u32 phy, sifs; 211 const struct ieee80211_rate *rate; 212 struct ieee80211_tx_rate *rates = info->status.rates; 213 214 rate = &common->sbands[info->band].bitrates[rates[ridx].idx]; 215 if (info->band == NL80211_BAND_2GHZ && 216 !(rate->flags & IEEE80211_RATE_ERP_G)) 217 phy = WLAN_RC_PHY_CCK; 218 else 219 phy = WLAN_RC_PHY_OFDM; 220 221 sifs = ath_dynack_get_sifs(ah, phy); 222 da->st_rbf.ts[da->st_rbf.t_rb].dur -= sifs; 223 } 224 225 ath_dbg(common, DYNACK, "{%pM} tx sample %u [dur %u][h %u-t %u]\n", 226 hdr->addr1, da->st_rbf.ts[da->st_rbf.t_rb].tstamp, 227 da->st_rbf.ts[da->st_rbf.t_rb].dur, da->st_rbf.h_rb, 228 (da->st_rbf.t_rb + 1) % ATH_DYN_BUF); 229 230 INCR(da->st_rbf.t_rb, ATH_DYN_BUF); 231 if (da->st_rbf.t_rb == da->st_rbf.h_rb) 232 INCR(da->st_rbf.h_rb, ATH_DYN_BUF); 233 234 ath_dynack_compute_to(ah); 235 236 spin_unlock_bh(&da->qlock); 237 } 238 EXPORT_SYMBOL(ath_dynack_sample_tx_ts); 239 240 /** 241 * ath_dynack_sample_ack_ts - ACK timestamp sampling method 242 * @ah: ath hw 243 * @skb: socket buffer 244 * @ts: rx timestamp 245 * 246 */ 247 void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb, 248 u32 ts) 249 { 250 struct ath_dynack *da = &ah->dynack; 251 struct ath_common *common = ath9k_hw_common(ah); 252 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; 253 254 if (!ath_dynack_bssidmask(ah, hdr->addr1) || !da->enabled) 255 return; 256 257 spin_lock_bh(&da->qlock); 258 da->ack_rbf.tstamp[da->ack_rbf.t_rb] = ts; 259 260 ath_dbg(common, DYNACK, "rx sample %u [h %u-t %u]\n", 261 da->ack_rbf.tstamp[da->ack_rbf.t_rb], 262 da->ack_rbf.h_rb, (da->ack_rbf.t_rb + 1) % ATH_DYN_BUF); 263 264 INCR(da->ack_rbf.t_rb, ATH_DYN_BUF); 265 if (da->ack_rbf.t_rb == da->ack_rbf.h_rb) 266 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF); 267 268 ath_dynack_compute_to(ah); 269 270 spin_unlock_bh(&da->qlock); 271 } 272 EXPORT_SYMBOL(ath_dynack_sample_ack_ts); 273 274 /** 275 * ath_dynack_node_init - init ath_node related info 276 * @ah: ath hw 277 * @an: ath node 278 * 279 */ 280 void ath_dynack_node_init(struct ath_hw *ah, struct ath_node *an) 281 { 282 /* ackto = slottime + sifs + air delay */ 283 u32 ackto = ATH9K_SLOT_TIME_9 + 16 + 64; 284 struct ath_dynack *da = &ah->dynack; 285 286 an->ackto = ackto; 287 288 spin_lock(&da->qlock); 289 list_add_tail(&an->list, &da->nodes); 290 spin_unlock(&da->qlock); 291 } 292 EXPORT_SYMBOL(ath_dynack_node_init); 293 294 /** 295 * ath_dynack_node_deinit - deinit ath_node related info 296 * @ah: ath hw 297 * @an: ath node 298 * 299 */ 300 void ath_dynack_node_deinit(struct ath_hw *ah, struct ath_node *an) 301 { 302 struct ath_dynack *da = &ah->dynack; 303 304 spin_lock(&da->qlock); 305 list_del(&an->list); 306 spin_unlock(&da->qlock); 307 } 308 EXPORT_SYMBOL(ath_dynack_node_deinit); 309 310 /** 311 * ath_dynack_reset - reset dynack processing 312 * @ah: ath hw 313 * 314 */ 315 void ath_dynack_reset(struct ath_hw *ah) 316 { 317 /* ackto = slottime + sifs + air delay */ 318 u32 ackto = ATH9K_SLOT_TIME_9 + 16 + 64; 319 struct ath_dynack *da = &ah->dynack; 320 321 da->lto = jiffies; 322 da->ackto = ackto; 323 324 da->st_rbf.t_rb = 0; 325 da->st_rbf.h_rb = 0; 326 da->ack_rbf.t_rb = 0; 327 da->ack_rbf.h_rb = 0; 328 329 /* init acktimeout */ 330 ath9k_hw_setslottime(ah, (ackto - 3) / 2); 331 ath9k_hw_set_ack_timeout(ah, ackto); 332 ath9k_hw_set_cts_timeout(ah, ackto); 333 } 334 EXPORT_SYMBOL(ath_dynack_reset); 335 336 /** 337 * ath_dynack_init - init dynack data structure 338 * @ah: ath hw 339 * 340 */ 341 void ath_dynack_init(struct ath_hw *ah) 342 { 343 struct ath_dynack *da = &ah->dynack; 344 345 memset(da, 0, sizeof(struct ath_dynack)); 346 347 spin_lock_init(&da->qlock); 348 INIT_LIST_HEAD(&da->nodes); 349 350 ah->hw->wiphy->features |= NL80211_FEATURE_ACKTO_ESTIMATION; 351 } 352