--- /dev/null
+/*
+ * Copyright (c) 2014, Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ath9k.h"
+#include "hw.h"
+#include "dynack.h"
+
+#define COMPUTE_TO (5 * HZ)
+#define LATEACK_DELAY (10 * HZ)
+#define LATEACK_TO 256
+#define MAX_DELAY 300
+#define EWMA_LEVEL 96
+#define EWMA_DIV 128
+
+/**
+ * ath_dynack_ewma - EWMA (Exponentially Weighted Moving Average) calculation
+ *
+ */
+static inline u32 ath_dynack_ewma(u32 old, u32 new)
+{
+ return (new * (EWMA_DIV - EWMA_LEVEL) + old * EWMA_LEVEL) / EWMA_DIV;
+}
+
+/**
+ * ath_dynack_get_sifs - get sifs time based on phy used
+ * @ah: ath hw
+ * @phy: phy used
+ *
+ */
+static inline u32 ath_dynack_get_sifs(struct ath_hw *ah, int phy)
+{
+ u32 sifs = CCK_SIFS_TIME;
+
+ if (phy == WLAN_RC_PHY_OFDM) {
+ if (IS_CHAN_QUARTER_RATE(ah->curchan))
+ sifs = OFDM_SIFS_TIME_QUARTER;
+ else if (IS_CHAN_HALF_RATE(ah->curchan))
+ sifs = OFDM_SIFS_TIME_HALF;
+ else
+ sifs = OFDM_SIFS_TIME;
+ }
+ return sifs;
+}
+
+/**
+ * ath_dynack_bssidmask - filter out ACK frames based on BSSID mask
+ * @ah: ath hw
+ * @mac: receiver address
+ */
+static inline bool ath_dynack_bssidmask(struct ath_hw *ah, const u8 *mac)
+{
+ int i;
+ struct ath_common *common = ath9k_hw_common(ah);
+
+ for (i = 0; i < ETH_ALEN; i++) {
+ if ((common->macaddr[i] & common->bssidmask[i]) !=
+ (mac[i] & common->bssidmask[i]))
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * ath_dynack_compute_ackto - compute ACK timeout as the maximum STA timeout
+ * @ah: ath hw
+ *
+ * should be called while holding qlock
+ */
+static void ath_dynack_compute_ackto(struct ath_hw *ah)
+{
+ struct ath_node *an;
+ u32 to = 0;
+ struct ath_dynack *da = &ah->dynack;
+ struct ath_common *common = ath9k_hw_common(ah);
+
+ list_for_each_entry(an, &da->nodes, list)
+ if (an->ackto > to)
+ to = an->ackto;
+
+ if (to && da->ackto != to) {
+ u32 slottime;
+
+ slottime = (to - 3) / 2;
+ da->ackto = to;
+ ath_dbg(common, DYNACK, "ACK timeout %u slottime %u\n",
+ da->ackto, slottime);
+ ath9k_hw_setslottime(ah, slottime);
+ ath9k_hw_set_ack_timeout(ah, da->ackto);
+ ath9k_hw_set_cts_timeout(ah, da->ackto);
+ }
+}
+
+/**
+ * ath_dynack_compute_to - compute STA ACK timeout
+ * @ah: ath hw
+ *
+ * should be called while holding qlock
+ */
+static void ath_dynack_compute_to(struct ath_hw *ah)
+{
+ u32 ackto, ack_ts;
+ u8 *dst, *src;
+ struct ieee80211_sta *sta;
+ struct ath_node *an;
+ struct ts_info *st_ts;
+ struct ath_dynack *da = &ah->dynack;
+
+ rcu_read_lock();
+
+ while (da->st_rbf.h_rb != da->st_rbf.t_rb &&
+ da->ack_rbf.h_rb != da->ack_rbf.t_rb) {
+ ack_ts = da->ack_rbf.tstamp[da->ack_rbf.h_rb];
+ st_ts = &da->st_rbf.ts[da->st_rbf.h_rb];
+ dst = da->st_rbf.addr[da->st_rbf.h_rb].h_dest;
+ src = da->st_rbf.addr[da->st_rbf.h_rb].h_src;
+
+ ath_dbg(ath9k_hw_common(ah), DYNACK,
+ "ack_ts %u st_ts %u st_dur %u [%u-%u]\n",
+ ack_ts, st_ts->tstamp, st_ts->dur,
+ da->ack_rbf.h_rb, da->st_rbf.h_rb);
+
+ if (ack_ts > st_ts->tstamp + st_ts->dur) {
+ ackto = ack_ts - st_ts->tstamp - st_ts->dur;
+
+ if (ackto < MAX_DELAY) {
+ sta = ieee80211_find_sta_by_ifaddr(ah->hw, dst,
+ src);
+ if (sta) {
+ an = (struct ath_node *)sta->drv_priv;
+ an->ackto = ath_dynack_ewma(an->ackto,
+ ackto);
+ ath_dbg(ath9k_hw_common(ah), DYNACK,
+ "%pM to %u\n", dst, an->ackto);
+ if (time_is_before_jiffies(da->lto)) {
+ ath_dynack_compute_ackto(ah);
+ da->lto = jiffies + COMPUTE_TO;
+ }
+ }
+ INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);
+ }
+ INCR(da->st_rbf.h_rb, ATH_DYN_BUF);
+ } else {
+ INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);
+ }
+ }
+
+ rcu_read_unlock();
+}
+
+/**
+ * ath_dynack_sample_tx_ts - status timestamp sampling method
+ * @ah: ath hw
+ * @skb: socket buffer
+ * @ts: tx status info
+ *
+ */
+void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
+ struct ath_tx_status *ts)
+{
+ u8 ridx;
+ struct ieee80211_hdr *hdr;
+ struct ath_dynack *da = &ah->dynack;
+ struct ath_common *common = ath9k_hw_common(ah);
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+
+ if ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !da->enabled)
+ return;
+
+ spin_lock_bh(&da->qlock);
+
+ hdr = (struct ieee80211_hdr *)skb->data;
+
+ /* late ACK */
+ if (ts->ts_status & ATH9K_TXERR_XRETRY) {
+ if (ieee80211_is_assoc_req(hdr->frame_control) ||
+ ieee80211_is_assoc_resp(hdr->frame_control)) {
+ ath_dbg(common, DYNACK, "late ack\n");
+ ath9k_hw_setslottime(ah, (LATEACK_TO - 3) / 2);
+ ath9k_hw_set_ack_timeout(ah, LATEACK_TO);
+ ath9k_hw_set_cts_timeout(ah, LATEACK_TO);
+ da->lto = jiffies + LATEACK_DELAY;
+ }
+
+ spin_unlock_bh(&da->qlock);
+ return;
+ }
+
+ ridx = ts->ts_rateindex;
+
+ da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp;
+ da->st_rbf.ts[da->st_rbf.t_rb].dur = ts->duration;
+ ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1);
+ ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2);
+
+ if (!(info->status.rates[ridx].flags & IEEE80211_TX_RC_MCS)) {
+ u32 phy, sifs;
+ const struct ieee80211_rate *rate;
+ struct ieee80211_tx_rate *rates = info->status.rates;
+
+ rate = &common->sbands[info->band].bitrates[rates[ridx].idx];
+ if (info->band == IEEE80211_BAND_2GHZ &&
+ !(rate->flags & IEEE80211_RATE_ERP_G))
+ phy = WLAN_RC_PHY_CCK;
+ else
+ phy = WLAN_RC_PHY_OFDM;
+
+ sifs = ath_dynack_get_sifs(ah, phy);
+ da->st_rbf.ts[da->st_rbf.t_rb].dur -= sifs;
+ }
+
+ ath_dbg(common, DYNACK, "{%pM} tx sample %u [dur %u][h %u-t %u]\n",
+ hdr->addr1, da->st_rbf.ts[da->st_rbf.t_rb].tstamp,
+ da->st_rbf.ts[da->st_rbf.t_rb].dur, da->st_rbf.h_rb,
+ (da->st_rbf.t_rb + 1) % ATH_DYN_BUF);
+
+ INCR(da->st_rbf.t_rb, ATH_DYN_BUF);
+ if (da->st_rbf.t_rb == da->st_rbf.h_rb)
+ INCR(da->st_rbf.h_rb, ATH_DYN_BUF);
+
+ ath_dynack_compute_to(ah);
+
+ spin_unlock_bh(&da->qlock);
+}
+EXPORT_SYMBOL(ath_dynack_sample_tx_ts);
+
+/**
+ * ath_dynack_sample_ack_ts - ACK timestamp sampling method
+ * @ah: ath hw
+ * @skb: socket buffer
+ * @ts: rx timestamp
+ *
+ */
+void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb,
+ u32 ts)
+{
+ struct ath_dynack *da = &ah->dynack;
+ struct ath_common *common = ath9k_hw_common(ah);
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+
+ if (!ath_dynack_bssidmask(ah, hdr->addr1) || !da->enabled)
+ return;
+
+ spin_lock_bh(&da->qlock);
+ da->ack_rbf.tstamp[da->ack_rbf.t_rb] = ts;
+
+ ath_dbg(common, DYNACK, "rx sample %u [h %u-t %u]\n",
+ da->ack_rbf.tstamp[da->ack_rbf.t_rb],
+ da->ack_rbf.h_rb, (da->ack_rbf.t_rb + 1) % ATH_DYN_BUF);
+
+ INCR(da->ack_rbf.t_rb, ATH_DYN_BUF);
+ if (da->ack_rbf.t_rb == da->ack_rbf.h_rb)
+ INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);
+
+ ath_dynack_compute_to(ah);
+
+ spin_unlock_bh(&da->qlock);
+}
+EXPORT_SYMBOL(ath_dynack_sample_ack_ts);
+
+/**
+ * ath_dynack_node_init - init ath_node related info
+ * @ah: ath hw
+ * @an: ath node
+ *
+ */
+void ath_dynack_node_init(struct ath_hw *ah, struct ath_node *an)
+{
+ /* ackto = slottime + sifs + air delay */
+ u32 ackto = ATH9K_SLOT_TIME_9 + 16 + 64;
+ struct ath_dynack *da = &ah->dynack;
+
+ an->ackto = ackto;
+
+ spin_lock(&da->qlock);
+ list_add_tail(&an->list, &da->nodes);
+ spin_unlock(&da->qlock);
+}
+EXPORT_SYMBOL(ath_dynack_node_init);
+
+/**
+ * ath_dynack_node_deinit - deinit ath_node related info
+ * @ah: ath hw
+ * @an: ath node
+ *
+ */
+void ath_dynack_node_deinit(struct ath_hw *ah, struct ath_node *an)
+{
+ struct ath_dynack *da = &ah->dynack;
+
+ spin_lock(&da->qlock);
+ list_del(&an->list);
+ spin_unlock(&da->qlock);
+}
+EXPORT_SYMBOL(ath_dynack_node_deinit);
+
+/**
+ * ath_dynack_reset - reset dynack processing
+ * @ah: ath hw
+ *
+ */
+void ath_dynack_reset(struct ath_hw *ah)
+{
+ /* ackto = slottime + sifs + air delay */
+ u32 ackto = ATH9K_SLOT_TIME_9 + 16 + 64;
+ struct ath_dynack *da = &ah->dynack;
+
+ da->lto = jiffies;
+ da->ackto = ackto;
+
+ da->st_rbf.t_rb = 0;
+ da->st_rbf.h_rb = 0;
+ da->ack_rbf.t_rb = 0;
+ da->ack_rbf.h_rb = 0;
+
+ /* init acktimeout */
+ ath9k_hw_setslottime(ah, (ackto - 3) / 2);
+ ath9k_hw_set_ack_timeout(ah, ackto);
+ ath9k_hw_set_cts_timeout(ah, ackto);
+}
+EXPORT_SYMBOL(ath_dynack_reset);
+
+/**
+ * ath_dynack_init - init dynack data structure
+ * @ah: ath hw
+ *
+ */
+void ath_dynack_init(struct ath_hw *ah)
+{
+ struct ath_dynack *da = &ah->dynack;
+
+ memset(da, 0, sizeof(struct ath_dynack));
+
+ spin_lock_init(&da->qlock);
+ INIT_LIST_HEAD(&da->nodes);
+
+ ah->hw->wiphy->features |= NL80211_FEATURE_ACKTO_ESTIMATION;
+}
Code Review / kvmfornfv.git / blobdiff