ath9k: Add a debugfs file "node_recv"

This would be useful when debugging RX performance issues.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/debug_sta.c b/drivers/net/wireless/ath/ath9k/debug_sta.c
index 3d11968..d33cc88 100644
--- a/drivers/net/wireless/ath/ath9k/debug_sta.c
+++ b/drivers/net/wireless/ath/ath9k/debug_sta.c
@@ -16,6 +16,10 @@
 
 #include "ath9k.h"
 
+/*************/
+/* node_aggr */
+/*************/
+
 static ssize_t read_file_node_aggr(struct file *file, char __user *user_buf,
 				   size_t count, loff_t *ppos)
 {
@@ -95,11 +99,171 @@
 	.llseek = default_llseek,
 };
 
+/*************/
+/* node_recv */
+/*************/
+
+void ath_debug_rate_stats(struct ath_softc *sc,
+			  struct ath_rx_status *rs,
+			  struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ath_hw *ah = sc->sc_ah;
+	struct ieee80211_rx_status *rxs;
+	struct ath_rx_rate_stats *rstats;
+	struct ieee80211_sta *sta;
+	struct ath_node *an;
+
+	if (!ieee80211_is_data(hdr->frame_control))
+		return;
+
+	rcu_read_lock();
+
+	sta = ieee80211_find_sta_by_ifaddr(sc->hw, hdr->addr2, NULL);
+	if (!sta)
+		goto exit;
+
+	an = (struct ath_node *) sta->drv_priv;
+	rstats = &an->rx_rate_stats;
+	rxs = IEEE80211_SKB_RXCB(skb);
+
+	if (IS_HT_RATE(rs->rs_rate)) {
+		if (rxs->rate_idx > ARRAY_SIZE(rstats->ht_stats))
+			goto exit;
+
+		if (rxs->flag & RX_FLAG_40MHZ)
+			rstats->ht_stats[rxs->rate_idx].ht40_cnt++;
+		else
+			rstats->ht_stats[rxs->rate_idx].ht20_cnt++;
+
+		if (rxs->flag & RX_FLAG_SHORT_GI)
+			rstats->ht_stats[rxs->rate_idx].sgi_cnt++;
+		else
+			rstats->ht_stats[rxs->rate_idx].lgi_cnt++;
+
+		goto exit;
+	}
+
+	if (IS_CCK_RATE(rs->rs_rate)) {
+		if (rxs->flag & RX_FLAG_SHORTPRE)
+			rstats->cck_stats[rxs->rate_idx].cck_sp_cnt++;
+		else
+			rstats->cck_stats[rxs->rate_idx].cck_lp_cnt++;
+
+		goto exit;
+	}
+
+	if (IS_OFDM_RATE(rs->rs_rate)) {
+		if (ah->curchan->chan->band == IEEE80211_BAND_2GHZ)
+			rstats->ofdm_stats[rxs->rate_idx - 4].ofdm_cnt++;
+		else
+			rstats->ofdm_stats[rxs->rate_idx].ofdm_cnt++;
+	}
+exit:
+	rcu_read_unlock();
+}
+
+#define PRINT_CCK_RATE(str, i, sp)					\
+	do {								\
+		len += scnprintf(buf + len, size - len,			\
+			 "%11s : %10u\n",				\
+			 str,						\
+			 (sp) ? rstats->cck_stats[i].cck_sp_cnt :	\
+			 rstats->cck_stats[i].cck_lp_cnt);		\
+	} while (0)
+
+#define PRINT_OFDM_RATE(str, i)					\
+	do {							\
+		len += scnprintf(buf + len, size - len,		\
+			 "%11s : %10u\n",			\
+			 str,					\
+			 rstats->ofdm_stats[i].ofdm_cnt);	\
+	} while (0)
+
+static ssize_t read_file_node_recv(struct file *file, char __user *user_buf,
+				   size_t count, loff_t *ppos)
+{
+	struct ath_node *an = file->private_data;
+	struct ath_softc *sc = an->sc;
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_rx_rate_stats *rstats;
+	struct ieee80211_sta *sta = an->sta;
+	enum ieee80211_band band;
+	u32 len = 0, size = 4096;
+	char *buf;
+	size_t retval;
+	int i;
+
+	buf = kzalloc(size, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	band = ah->curchan->chan->band;
+	rstats = &an->rx_rate_stats;
+
+	if (!sta->ht_cap.ht_supported)
+		goto legacy;
+
+	len += scnprintf(buf + len, size - len,
+			 "%24s%10s%10s%10s\n",
+			 "HT20", "HT40", "SGI", "LGI");
+
+	for (i = 0; i < 24; i++) {
+		len += scnprintf(buf + len, size - len,
+				 "%8s%3u : %10u%10u%10u%10u\n",
+				 "MCS", i,
+				 rstats->ht_stats[i].ht20_cnt,
+				 rstats->ht_stats[i].ht40_cnt,
+				 rstats->ht_stats[i].sgi_cnt,
+				 rstats->ht_stats[i].lgi_cnt);
+	}
+
+	len += scnprintf(buf + len, size - len, "\n");
+
+legacy:
+	if (band == IEEE80211_BAND_2GHZ) {
+		PRINT_CCK_RATE("CCK-1M/LP", 0, false);
+		PRINT_CCK_RATE("CCK-2M/LP", 1, false);
+		PRINT_CCK_RATE("CCK-5.5M/LP", 2, false);
+		PRINT_CCK_RATE("CCK-11M/LP", 3, false);
+
+		PRINT_CCK_RATE("CCK-2M/SP", 1, true);
+		PRINT_CCK_RATE("CCK-5.5M/SP", 2, true);
+		PRINT_CCK_RATE("CCK-11M/SP", 3, true);
+	}
+
+	PRINT_OFDM_RATE("OFDM-6M", 0);
+	PRINT_OFDM_RATE("OFDM-9M", 1);
+	PRINT_OFDM_RATE("OFDM-12M", 2);
+	PRINT_OFDM_RATE("OFDM-18M", 3);
+	PRINT_OFDM_RATE("OFDM-24M", 4);
+	PRINT_OFDM_RATE("OFDM-36M", 5);
+	PRINT_OFDM_RATE("OFDM-48M", 6);
+	PRINT_OFDM_RATE("OFDM-54M", 7);
+
+	retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+
+	return retval;
+}
+
+#undef PRINT_OFDM_RATE
+#undef PRINT_CCK_RATE
+
+static const struct file_operations fops_node_recv = {
+	.read = read_file_node_recv,
+	.open = simple_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
 void ath9k_sta_add_debugfs(struct ieee80211_hw *hw,
 			   struct ieee80211_vif *vif,
 			   struct ieee80211_sta *sta,
 			   struct dentry *dir)
 {
 	struct ath_node *an = (struct ath_node *)sta->drv_priv;
+
 	debugfs_create_file("node_aggr", S_IRUGO, dir, an, &fops_node_aggr);
+	debugfs_create_file("node_recv", S_IRUGO, dir, an, &fops_node_recv);
 }