ath9k: add dynamic ACK timeout estimation

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@gmail.com>
Tested-by: Philippe Duchein <wireless-dev@duchein.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/dynack.h b/drivers/net/wireless/ath/ath9k/dynack.h
new file mode 100644
index 000000000000..6d7bef976742
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/dynack.h
@@ -0,0 +1,103 @@
+/*
+ * 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.
+ */
+
+#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 */