wifi: mac80211: add debugfs file to display per-phy AQL pending airtime

Now that the global pending airtime is more relevant for airtime fairness,
it makes sense to make it accessible via debugfs for debugging
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/r/20220625212411.36675-6-nbd@nbd.nameSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/debugfs.c

@@ -201,6 +201,36 @@ static const struct file_operations airtime_flags_ops = {
 	.llseek = default_llseek,
 };
 
+static ssize_t aql_pending_read(struct file *file,
+				char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	struct ieee80211_local *local = file->private_data;
+	char buf[400];
+	int len = 0;
+
+	len = scnprintf(buf, sizeof(buf),
+			"AC     AQL pending\n"
+			"VO     %u us\n"
+			"VI     %u us\n"
+			"BE     %u us\n"
+			"BK     %u us\n"
+			"total  %u us\n",
+			atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VO]),
+			atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_VI]),
+			atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BE]),
+			atomic_read(&local->aql_ac_pending_airtime[IEEE80211_AC_BK]),
+			atomic_read(&local->aql_total_pending_airtime));
+	return simple_read_from_buffer(user_buf, count, ppos,
+				       buf, len);
+}
+
+static const struct file_operations aql_pending_ops = {
+	.read = aql_pending_read,
+	.open = simple_open,
+	.llseek = default_llseek,
+};
+
 static ssize_t aql_txq_limit_read(struct file *file,
 				  char __user *user_buf,
 				  size_t count,
@@ -631,6 +661,7 @@ void debugfs_hw_add(struct ieee80211_local *local)
 	DEBUGFS_ADD(hw_conf);
 	DEBUGFS_ADD_MODE(force_tx_status, 0600);
 	DEBUGFS_ADD_MODE(aql_enable, 0600);
+	DEBUGFS_ADD(aql_pending);
 
 	if (local->ops->wake_tx_queue)
 		DEBUGFS_ADD_MODE(aqm, 0600);