mac80211: clean up rate control API

Long awaited, hard work. This patch totally cleans up the rate control
API to remove the requirement to include internal headers outside of
net/mac80211/.

There's one internal use in the PID algorithm left for mesh networking,
we'll have to figure out a way to clean that one up and decide how to
do the peer link evaluation, possibly independent of the rate control
algorithm or via new API.

Additionally, ath9k is left using the cross-inclusion hack for now, we
will add new API where necessary to make this work properly, but right
now I'm not expert enough to do it. It's still off better than before.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 68 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 003e4a03874..f5f5b1ff158 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1800,4 +1800,72 @@ void ieee80211_notify_mac(struct ieee80211_hw *hw,
 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_hw *hw,
 					 const u8 *addr);
 
+
+/* Rate control API */
+/**
+ * struct rate_selection - rate information for/from rate control algorithms
+ *
+ * @rate_idx: selected transmission rate index
+ * @nonerp_idx: Non-ERP rate to use instead if ERP cannot be used
+ * @probe_idx: rate for probing (or -1)
+ * @max_rate_idx: maximum rate index that can be used, this is
+ *	input to the algorithm and will be enforced
+ */
+struct rate_selection {
+	s8 rate_idx, nonerp_idx, probe_idx, max_rate_idx;
+};
+
+struct rate_control_ops {
+	struct module *module;
+	const char *name;
+	void *(*alloc)(struct ieee80211_hw *hw, struct dentry *debugfsdir);
+	void (*clear)(void *priv);
+	void (*free)(void *priv);
+
+	void *(*alloc_sta)(void *priv, struct ieee80211_sta *sta, gfp_t gfp);
+	void (*rate_init)(void *priv, struct ieee80211_supported_band *sband,
+			  struct ieee80211_sta *sta, void *priv_sta);
+	void (*free_sta)(void *priv, struct ieee80211_sta *sta,
+			 void *priv_sta);
+
+	void (*tx_status)(void *priv, struct ieee80211_supported_band *sband,
+			  struct ieee80211_sta *sta, void *priv_sta,
+			  struct sk_buff *skb);
+	void (*get_rate)(void *priv, struct ieee80211_supported_band *sband,
+			 struct ieee80211_sta *sta, void *priv_sta,
+			 struct sk_buff *skb,
+			 struct rate_selection *sel);
+
+	void (*add_sta_debugfs)(void *priv, void *priv_sta,
+				struct dentry *dir);
+	void (*remove_sta_debugfs)(void *priv, void *priv_sta);
+};
+
+static inline int rate_supported(struct ieee80211_sta *sta,
+				 enum ieee80211_band band,
+				 int index)
+{
+	return (sta == NULL || sta->supp_rates[band] & BIT(index));
+}
+
+static inline s8
+rate_lowest_index(struct ieee80211_supported_band *sband,
+		  struct ieee80211_sta *sta)
+{
+	int i;
+
+	for (i = 0; i < sband->n_bitrates; i++)
+		if (rate_supported(sta, sband->band, i))
+			return i;
+
+	/* warn when we cannot find a rate. */
+	WARN_ON(1);
+
+	return 0;
+}
+
+
+int ieee80211_rate_control_register(struct rate_control_ops *ops);
+void ieee80211_rate_control_unregister(struct rate_control_ops *ops);
+
 #endif /* MAC80211_H */