mac80211: move csa counters from sdata to beacon/presp

Having csa counters part of beacon and probe_resp
structures makes it easier to get rid of possible
races between setting a beacon and updating
counters on SMP systems by guaranteeing counters
are always consistent against given beacon struct.

While at it relax WARN_ON into WARN_ON_ONCE to
prevent spamming logs and racing.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
[remove pointless array check]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4372d48..d9af7ef 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -229,16 +229,29 @@
 	u16 tkip_iv16;
 };
 
+struct ieee80211_csa_settings {
+	const u16 *counter_offsets_beacon;
+	const u16 *counter_offsets_presp;
+
+	int n_counter_offsets_beacon;
+	int n_counter_offsets_presp;
+
+	u8 count;
+};
+
 struct beacon_data {
 	u8 *head, *tail;
 	int head_len, tail_len;
 	struct ieee80211_meshconf_ie *meshconf;
+	u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
+	u8 csa_current_counter;
 	struct rcu_head rcu_head;
 };
 
 struct probe_resp {
 	struct rcu_head rcu_head;
 	int len;
+	u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
 	u8 data[0];
 };
 
@@ -754,8 +767,6 @@
 	struct mac80211_qos_map __rcu *qos_map;
 
 	struct work_struct csa_finalize_work;
-	u16 csa_counter_offset_beacon[IEEE80211_MAX_CSA_COUNTERS_NUM];
-	u16 csa_counter_offset_presp[IEEE80211_MAX_CSA_COUNTERS_NUM];
 	bool csa_radar_required;
 	bool csa_block_tx; /* write-protected by sdata_lock and local->mtx */
 	struct cfg80211_chan_def csa_chandef;
@@ -767,7 +778,6 @@
 	struct ieee80211_chanctx *reserved_chanctx;
 	struct cfg80211_chan_def reserved_chandef;
 	bool reserved_radar_required;
-	u8 csa_current_counter;
 
 	/* used to reconfigure hardware SM PS */
 	struct work_struct recalc_smps;