cfg80211: introduce critical protocol indication from user-space

Some protocols need a more reliable connection to complete
successful in reasonable time. This patch adds a user-space
API to indicate the wireless driver that a critical protocol
is about to commence and when it is done, using nl80211 primitives
NL80211_CMD_CRIT_PROTOCOL_START and NL80211_CRIT_PROTOCOL_STOP.

There can be only on critical protocol session started per
registered cfg80211 device.

The driver can support this by implementing the cfg80211 callbacks
.crit_proto_start() and .crit_proto_stop(). Examples of protocols
that can benefit from this are DHCP, EAPOL, APIPA. Exactly how the
link can/should be made more reliable is up to the driver. Things
to consider are avoid scanning, no multi-channel operations, and
alter coexistence schemes.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 3c2033b..ecd4fce 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1806,6 +1806,41 @@
 		  WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->md)
 );
 
+TRACE_EVENT(rdev_crit_proto_start,
+	TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev,
+		 enum nl80211_crit_proto_id protocol, u16 duration),
+	TP_ARGS(wiphy, wdev, protocol, duration),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		WDEV_ENTRY
+		__field(u16, proto)
+		__field(u16, duration)
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		WDEV_ASSIGN;
+		__entry->proto = protocol;
+		__entry->duration = duration;
+	),
+	TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT ", proto=%x, duration=%u",
+		  WIPHY_PR_ARG, WDEV_PR_ARG, __entry->proto, __entry->duration)
+);
+
+TRACE_EVENT(rdev_crit_proto_stop,
+	TP_PROTO(struct wiphy *wiphy, struct wireless_dev *wdev),
+	TP_ARGS(wiphy, wdev),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		WDEV_ENTRY
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		WDEV_ASSIGN;
+	),
+	TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT,
+		  WIPHY_PR_ARG, WDEV_PR_ARG)
+);
+
 /*************************************************************
  *	     cfg80211 exported functions traces		     *
  *************************************************************/