mac80211: allow drivers to report CLOCK_BOOTTIME for scan results

This was requested by Android, and the appropriate cfg80211 API
had been added by Dmitry. Support it in mac80211, allowing drivers
to provide the timestamp.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1120,6 +1120,8 @@ enum mac80211_rx_vht_flags {
  *
  * @mactime: value in microseconds of the 64-bit Time Synchronization Function
  * 	(TSF) timer when the first data symbol (MPDU) arrived at the hardware.
+ * @boottime_ns: CLOCK_BOOTTIME timestamp the frame was received at, this is
+ *	needed only for beacons and probe responses that update the scan cache.
  * @device_timestamp: arbitrary timestamp for the device, mac80211 doesn't use
  *	it but can store it and pass it back to the driver for synchronisation
  * @band: the active band when this frame was received
@@ -1146,6 +1148,7 @@ enum mac80211_rx_vht_flags {
  */
 struct ieee80211_rx_status {
 	u64 mactime;
+	u64 boottime_ns;
 	u32 device_timestamp;
 	u32 ampdu_reference;
 	u32 flag;

net/mac80211/scan.c

@@ -66,7 +66,9 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
 	struct cfg80211_bss *cbss;
 	struct ieee80211_bss *bss;
 	int clen, srlen;
-	struct cfg80211_inform_bss bss_meta = {};
+	struct cfg80211_inform_bss bss_meta = {
+		.boottime_ns = rx_status->boottime_ns,
+	};
 	bool signal_valid;
 
 	if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))