Add dynamic ACK timeout estimation algorithm based on ACK frame RX timestamp,
TX frame timestamp and frame duration.
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx>
Tested-by: Philippe Duchein <wireless-dev@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath.h | 2 +
drivers/net/wireless/ath/ath9k/ath9k.h | 3 +
drivers/net/wireless/ath/ath9k/dynack.c | 352 ++++++++++++++++++++++++++++++++
drivers/net/wireless/ath/ath9k/dynack.h | 103 ++++++++++
drivers/net/wireless/ath/ath9k/hw.c | 2 +
drivers/net/wireless/ath/ath9k/hw.h | 3 +
6 files changed, 465 insertions(+)
create mode 100644 drivers/net/wireless/ath/ath9k/dynack.c
create mode 100644 drivers/net/wireless/ath/ath9k/dynack.h
diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index c1a4ade..a3b6e27 100644
--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -234,6 +234,7 @@ void ath_printk(const char *level, const struct ath_common *common,
* AR9462.
* @ATH_DBG_DFS: radar datection
* @ATH_DBG_WOW: Wake on Wireless
+ * @ATH_DBG_DYNACK: dynack handling
* @ATH_DBG_ANY: enable all debugging
*
* The debug level is used to control the amount and type of debugging output
@@ -262,6 +263,7 @@ enum ATH_DEBUG {
ATH_DBG_DFS = 0x00010000,
ATH_DBG_WOW = 0x00020000,
ATH_DBG_CHAN_CTX = 0x00040000,
+ ATH_DBG_DYNACK = 0x00080000,
ATH_DBG_ANY = 0xffffffff
};
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index dd0f97f..8cd116e 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -274,6 +274,9 @@ struct ath_node {
struct ath_rx_rate_stats rx_rate_stats;
#endif
u8 key_idx[4];
+
+ u32 ackto;
+ struct list_head list;
};
struct ath_tx_control {
diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
new file mode 100644
index 0000000..ceca509
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -0,0 +1,352 @@
+/*
+ * Copyright (c) 2014, Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx>
+ *
+ * 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[ts->ts_rateindex];
+ 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;
+}
+
diff --git a/drivers/net/wireless/ath/ath9k/dynack.h b/drivers/net/wireless/ath/ath9k/dynack.h
new file mode 100644
index 0000000..6d7bef9
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/dynack.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2014, Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef DYNACK_H
+#define DYNACK_H
+
+#define ATH_DYN_BUF 64
+
+struct ath_hw;
+struct ath_node;
+
+/**
+ * struct ath_dyn_rxbuf - ACK frame ring buffer
+ * @h_rb: ring buffer head
+ * @t_rb: ring buffer tail
+ * @tstamp: ACK RX timestamp buffer
+ */
+struct ath_dyn_rxbuf {
+ u16 h_rb, t_rb;
+ u32 tstamp[ATH_DYN_BUF];
+};
+
+struct ts_info {
+ u32 tstamp;
+ u32 dur;
+};
+
+struct haddr_pair {
+ u8 h_dest[ETH_ALEN];
+ u8 h_src[ETH_ALEN];
+};
+
+/**
+ * struct ath_dyn_txbuf - tx frame ring buffer
+ * @h_rb: ring buffer head
+ * @t_rb: ring buffer tail
+ * @addr: dest/src address pair for a given TX frame
+ * @ts: TX frame timestamp buffer
+ */
+struct ath_dyn_txbuf {
+ u16 h_rb, t_rb;
+ struct haddr_pair addr[ATH_DYN_BUF];
+ struct ts_info ts[ATH_DYN_BUF];
+};
+
+/**
+ * struct ath_dynack - dynack processing info
+ * @enabled: enable dyn ack processing
+ * @ackto: current ACK timeout
+ * @lto: last ACK timeout computation
+ * @nodes: ath_node linked list
+ * @qlock: ts queue spinlock
+ * @ack_rbf: ACK ts ring buffer
+ * @st_rbf: status ts ring buffer
+ */
+struct ath_dynack {
+ bool enabled;
+ int ackto;
+ unsigned long lto;
+
+ struct list_head nodes;
+
+ /* protect timestamp queue access */
+ spinlock_t qlock;
+ struct ath_dyn_rxbuf ack_rbf;
+ struct ath_dyn_txbuf st_rbf;
+};
+
+#if defined(CONFIG_ATH9K_DYNACK)
+void ath_dynack_reset(struct ath_hw *ah);
+void ath_dynack_node_init(struct ath_hw *ah, struct ath_node *an);
+void ath_dynack_node_deinit(struct ath_hw *ah, struct ath_node *an);
+void ath_dynack_init(struct ath_hw *ah);
+void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb, u32 ts);
+void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
+ struct ath_tx_status *ts);
+#else
+static inline void ath_dynack_init(struct ath_hw *ah) {}
+static inline void ath_dynack_node_init(struct ath_hw *ah,
+ struct ath_node *an) {}
+static inline void ath_dynack_node_deinit(struct ath_hw *ah,
+ struct ath_node *an) {}
+static inline void ath_dynack_sample_ack_ts(struct ath_hw *ah,
+ struct sk_buff *skb, u32 ts) {}
+static inline void ath_dynack_sample_tx_ts(struct ath_hw *ah,
+ struct sk_buff *skb,
+ struct ath_tx_status *ts) {}
+#endif
+
+#endif /* DYNACK_H */
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index ce395e2..e71f824 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -647,6 +647,8 @@ int ath9k_hw_init(struct ath_hw *ah)
return ret;
}
+ ath_dynack_init(ah);
+
return 0;
}
EXPORT_SYMBOL(ath9k_hw_init);
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index f36d971..b9eef33 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -29,6 +29,7 @@
#include "reg.h"
#include "phy.h"
#include "btcoex.h"
+#include "dynack.h"
#include "../regd.h"
@@ -924,6 +925,8 @@ struct ath_hw {
int (*external_reset)(void);
const struct firmware *eeprom_blob;
+
+ struct ath_dynack dynack;
};
struct ath_bus_ops {
--
1.9.1
--
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