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1/*2 * Copyright (c) 2014, Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>3 *4 * Permission to use, copy, modify, and/or distribute this software for any5 * purpose with or without fee is hereby granted, provided that the above6 * copyright notice and this permission notice appear in all copies.7 *8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF14 * 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 EWMA_LEVEL 9624#define EWMA_DIV 12825 26/**27 * ath_dynack_get_max_to - set max timeout according to channel width28 * @ah: ath hw29 *30 */31static u32 ath_dynack_get_max_to(struct ath_hw *ah)32{33 const struct ath9k_channel *chan = ah->curchan;34 35 if (!chan)36 return 300;37 38 if (IS_CHAN_HT40(chan))39 return 300;40 if (IS_CHAN_HALF_RATE(chan))41 return 750;42 if (IS_CHAN_QUARTER_RATE(chan))43 return 1500;44 return 600;45}46 47/*48 * ath_dynack_ewma - EWMA (Exponentially Weighted Moving Average) calculation49 */50static inline int ath_dynack_ewma(int old, int new)51{52 if (old > 0)53 return (new * (EWMA_DIV - EWMA_LEVEL) +54 old * EWMA_LEVEL) / EWMA_DIV;55 else56 return new;57}58 59/**60 * ath_dynack_get_sifs - get sifs time based on phy used61 * @ah: ath hw62 * @phy: phy used63 *64 */65static inline u32 ath_dynack_get_sifs(struct ath_hw *ah, int phy)66{67 u32 sifs = CCK_SIFS_TIME;68 69 if (phy == WLAN_RC_PHY_OFDM) {70 if (IS_CHAN_QUARTER_RATE(ah->curchan))71 sifs = OFDM_SIFS_TIME_QUARTER;72 else if (IS_CHAN_HALF_RATE(ah->curchan))73 sifs = OFDM_SIFS_TIME_HALF;74 else75 sifs = OFDM_SIFS_TIME;76 }77 return sifs;78}79 80/**81 * ath_dynack_bssidmask - filter out ACK frames based on BSSID mask82 * @ah: ath hw83 * @mac: receiver address84 */85static inline bool ath_dynack_bssidmask(struct ath_hw *ah, const u8 *mac)86{87 int i;88 struct ath_common *common = ath9k_hw_common(ah);89 90 for (i = 0; i < ETH_ALEN; i++) {91 if ((common->macaddr[i] & common->bssidmask[i]) !=92 (mac[i] & common->bssidmask[i]))93 return false;94 }95 96 return true;97}98 99/**100 * ath_dynack_set_timeout - configure timeouts/slottime registers101 * @ah: ath hw102 * @to: timeout value103 *104 */105static void ath_dynack_set_timeout(struct ath_hw *ah, int to)106{107 struct ath_common *common = ath9k_hw_common(ah);108 int slottime = (to - 3) / 2;109 110 ath_dbg(common, DYNACK, "ACK timeout %u slottime %u\n",111 to, slottime);112 ath9k_hw_setslottime(ah, slottime);113 ath9k_hw_set_ack_timeout(ah, to);114 ath9k_hw_set_cts_timeout(ah, to);115}116 117/**118 * ath_dynack_compute_ackto - compute ACK timeout as the maximum STA timeout119 * @ah: ath hw120 *121 * should be called while holding qlock122 */123static void ath_dynack_compute_ackto(struct ath_hw *ah)124{125 struct ath_dynack *da = &ah->dynack;126 struct ath_node *an;127 int to = 0;128 129 list_for_each_entry(an, &da->nodes, list)130 if (an->ackto > to)131 to = an->ackto;132 133 if (to && da->ackto != to) {134 ath_dynack_set_timeout(ah, to);135 da->ackto = to;136 }137}138 139/**140 * ath_dynack_compute_to - compute STA ACK timeout141 * @ah: ath hw142 *143 * should be called while holding qlock144 */145static void ath_dynack_compute_to(struct ath_hw *ah)146{147 struct ath_dynack *da = &ah->dynack;148 u32 ackto, ack_ts, max_to;149 struct ieee80211_sta *sta;150 struct ts_info *st_ts;151 struct ath_node *an;152 u8 *dst, *src;153 154 rcu_read_lock();155 156 max_to = ath_dynack_get_max_to(ah);157 while (da->st_rbf.h_rb != da->st_rbf.t_rb &&158 da->ack_rbf.h_rb != da->ack_rbf.t_rb) {159 ack_ts = da->ack_rbf.tstamp[da->ack_rbf.h_rb];160 st_ts = &da->st_rbf.ts[da->st_rbf.h_rb];161 dst = da->st_rbf.addr[da->st_rbf.h_rb].h_dest;162 src = da->st_rbf.addr[da->st_rbf.h_rb].h_src;163 164 ath_dbg(ath9k_hw_common(ah), DYNACK,165 "ack_ts %u st_ts %u st_dur %u [%u-%u]\n",166 ack_ts, st_ts->tstamp, st_ts->dur,167 da->ack_rbf.h_rb, da->st_rbf.h_rb);168 169 if (ack_ts > st_ts->tstamp + st_ts->dur) {170 ackto = ack_ts - st_ts->tstamp - st_ts->dur;171 172 if (ackto < max_to) {173 sta = ieee80211_find_sta_by_ifaddr(ah->hw, dst,174 src);175 if (sta) {176 an = (struct ath_node *)sta->drv_priv;177 an->ackto = ath_dynack_ewma(an->ackto,178 ackto);179 ath_dbg(ath9k_hw_common(ah), DYNACK,180 "%pM to %d [%u]\n", dst,181 an->ackto, ackto);182 if (time_is_before_jiffies(da->lto)) {183 ath_dynack_compute_ackto(ah);184 da->lto = jiffies + COMPUTE_TO;185 }186 }187 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);188 }189 INCR(da->st_rbf.h_rb, ATH_DYN_BUF);190 } else {191 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);192 }193 }194 195 rcu_read_unlock();196}197 198/**199 * ath_dynack_sample_tx_ts - status timestamp sampling method200 * @ah: ath hw201 * @skb: socket buffer202 * @ts: tx status info203 * @sta: station pointer204 *205 */206void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,207 struct ath_tx_status *ts,208 struct ieee80211_sta *sta)209{210 struct ieee80211_hdr *hdr;211 struct ath_dynack *da = &ah->dynack;212 struct ath_common *common = ath9k_hw_common(ah);213 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);214 u32 dur = ts->duration;215 u8 ridx;216 217 if (!da->enabled || (info->flags & IEEE80211_TX_CTL_NO_ACK))218 return;219 220 spin_lock_bh(&da->qlock);221 222 hdr = (struct ieee80211_hdr *)skb->data;223 224 /* late ACK */225 if (ts->ts_status & ATH9K_TXERR_XRETRY) {226 if (ieee80211_is_assoc_req(hdr->frame_control) ||227 ieee80211_is_assoc_resp(hdr->frame_control) ||228 ieee80211_is_auth(hdr->frame_control)) {229 u32 max_to = ath_dynack_get_max_to(ah);230 231 ath_dbg(common, DYNACK, "late ack\n");232 ath_dynack_set_timeout(ah, max_to);233 if (sta) {234 struct ath_node *an;235 236 an = (struct ath_node *)sta->drv_priv;237 an->ackto = -1;238 }239 da->lto = jiffies + LATEACK_DELAY;240 }241 242 spin_unlock_bh(&da->qlock);243 return;244 }245 246 ridx = ts->ts_rateindex;247 248 da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp;249 250 /* ether_addr_copy() gives a false warning on gcc-10 so use memcpy()251 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490252 */253 memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1, ETH_ALEN);254 memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2, ETH_ALEN);255 256 if (!(info->status.rates[ridx].flags & IEEE80211_TX_RC_MCS)) {257 const struct ieee80211_rate *rate;258 struct ieee80211_tx_rate *rates = info->status.rates;259 u32 phy;260 261 rate = &common->sbands[info->band].bitrates[rates[ridx].idx];262 if (info->band == NL80211_BAND_2GHZ &&263 !(rate->flags & IEEE80211_RATE_ERP_G))264 phy = WLAN_RC_PHY_CCK;265 else266 phy = WLAN_RC_PHY_OFDM;267 268 dur -= ath_dynack_get_sifs(ah, phy);269 }270 da->st_rbf.ts[da->st_rbf.t_rb].dur = dur;271 272 INCR(da->st_rbf.t_rb, ATH_DYN_BUF);273 if (da->st_rbf.t_rb == da->st_rbf.h_rb)274 INCR(da->st_rbf.h_rb, ATH_DYN_BUF);275 276 ath_dbg(common, DYNACK, "{%pM} tx sample %u [dur %u][h %u-t %u]\n",277 hdr->addr1, ts->ts_tstamp, dur, da->st_rbf.h_rb,278 da->st_rbf.t_rb);279 280 ath_dynack_compute_to(ah);281 282 spin_unlock_bh(&da->qlock);283}284EXPORT_SYMBOL(ath_dynack_sample_tx_ts);285 286/**287 * ath_dynack_sample_ack_ts - ACK timestamp sampling method288 * @ah: ath hw289 * @skb: socket buffer290 * @ts: rx timestamp291 *292 */293void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb,294 u32 ts)295{296 struct ath_dynack *da = &ah->dynack;297 struct ath_common *common = ath9k_hw_common(ah);298 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;299 300 if (!da->enabled || !ath_dynack_bssidmask(ah, hdr->addr1))301 return;302 303 spin_lock_bh(&da->qlock);304 da->ack_rbf.tstamp[da->ack_rbf.t_rb] = ts;305 306 INCR(da->ack_rbf.t_rb, ATH_DYN_BUF);307 if (da->ack_rbf.t_rb == da->ack_rbf.h_rb)308 INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);309 310 ath_dbg(common, DYNACK, "rx sample %u [h %u-t %u]\n",311 ts, da->ack_rbf.h_rb, da->ack_rbf.t_rb);312 313 ath_dynack_compute_to(ah);314 315 spin_unlock_bh(&da->qlock);316}317EXPORT_SYMBOL(ath_dynack_sample_ack_ts);318 319/**320 * ath_dynack_node_init - init ath_node related info321 * @ah: ath hw322 * @an: ath node323 *324 */325void ath_dynack_node_init(struct ath_hw *ah, struct ath_node *an)326{327 struct ath_dynack *da = &ah->dynack;328 329 an->ackto = da->ackto;330 331 spin_lock_bh(&da->qlock);332 list_add_tail(&an->list, &da->nodes);333 spin_unlock_bh(&da->qlock);334}335EXPORT_SYMBOL(ath_dynack_node_init);336 337/**338 * ath_dynack_node_deinit - deinit ath_node related info339 * @ah: ath hw340 * @an: ath node341 *342 */343void ath_dynack_node_deinit(struct ath_hw *ah, struct ath_node *an)344{345 struct ath_dynack *da = &ah->dynack;346 347 spin_lock_bh(&da->qlock);348 list_del(&an->list);349 spin_unlock_bh(&da->qlock);350}351EXPORT_SYMBOL(ath_dynack_node_deinit);352 353/**354 * ath_dynack_reset - reset dynack processing355 * @ah: ath hw356 *357 */358void ath_dynack_reset(struct ath_hw *ah)359{360 struct ath_dynack *da = &ah->dynack;361 struct ath_node *an;362 363 spin_lock_bh(&da->qlock);364 365 da->lto = jiffies + COMPUTE_TO;366 367 da->st_rbf.t_rb = 0;368 da->st_rbf.h_rb = 0;369 da->ack_rbf.t_rb = 0;370 da->ack_rbf.h_rb = 0;371 372 da->ackto = ath_dynack_get_max_to(ah);373 list_for_each_entry(an, &da->nodes, list)374 an->ackto = da->ackto;375 376 /* init acktimeout */377 ath_dynack_set_timeout(ah, da->ackto);378 379 spin_unlock_bh(&da->qlock);380}381EXPORT_SYMBOL(ath_dynack_reset);382 383/**384 * ath_dynack_init - init dynack data structure385 * @ah: ath hw386 *387 */388void ath_dynack_init(struct ath_hw *ah)389{390 struct ath_dynack *da = &ah->dynack;391 392 memset(da, 0, sizeof(struct ath_dynack));393 394 spin_lock_init(&da->qlock);395 INIT_LIST_HEAD(&da->nodes);396 /* ackto = slottime + sifs + air delay */397 da->ackto = 9 + 16 + 64;398 399 ah->hw->wiphy->features |= NL80211_FEATURE_ACKTO_ESTIMATION;400}401