wil6210: add TX latency statistics

Collect statistics of TX latency. The latency is measured from the time
the HW gets aware of new SKB to transmit until the HW indicates tx
complete for this SKB.
The statistics are shown via new "tx_latency" debugfs.

Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 125 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index 99b1fc5b796f..5d1e48d80f0d 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -1800,6 +1800,126 @@ static const struct file_operations fops_mids = {
 	.llseek		= seq_lseek,
 };
 
+static int wil_tx_latency_debugfs_show(struct seq_file *s, void *data)
+__acquires(&p->tid_rx_lock) __releases(&p->tid_rx_lock)
+{
+	struct wil6210_priv *wil = s->private;
+	int i, bin;
+
+	for (i = 0; i < ARRAY_SIZE(wil->sta); i++) {
+		struct wil_sta_info *p = &wil->sta[i];
+		char *status = "unknown";
+		u8 aid = 0;
+		u8 mid;
+
+		if (!p->tx_latency_bins)
+			continue;
+
+		switch (p->status) {
+		case wil_sta_unused:
+			status = "unused   ";
+			break;
+		case wil_sta_conn_pending:
+			status = "pending  ";
+			break;
+		case wil_sta_connected:
+			status = "connected";
+			aid = p->aid;
+			break;
+		}
+		mid = (p->status != wil_sta_unused) ? p->mid : U8_MAX;
+		seq_printf(s, "[%d] %pM %s MID %d AID %d\n", i, p->addr, status,
+			   mid, aid);
+
+		if (p->status == wil_sta_connected) {
+			u64 num_packets = 0;
+			u64 tx_latency_avg = p->stats.tx_latency_total_us;
+
+			seq_puts(s, "Tx/Latency bin:");
+			for (bin = 0; bin < WIL_NUM_LATENCY_BINS; bin++) {
+				seq_printf(s, " %lld",
+					   p->tx_latency_bins[bin]);
+				num_packets += p->tx_latency_bins[bin];
+			}
+			seq_puts(s, "\n");
+			if (!num_packets)
+				continue;
+			do_div(tx_latency_avg, num_packets);
+			seq_printf(s, "Tx/Latency min/avg/max (us): %d/%lld/%d",
+				   p->stats.tx_latency_min_us,
+				   tx_latency_avg,
+				   p->stats.tx_latency_max_us);
+
+			seq_puts(s, "\n");
+		}
+	}
+
+	return 0;
+}
+
+static int wil_tx_latency_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, wil_tx_latency_debugfs_show,
+			   inode->i_private);
+}
+
+static ssize_t wil_tx_latency_write(struct file *file, const char __user *buf,
+				    size_t len, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct wil6210_priv *wil = s->private;
+	int val, rc, i;
+	bool enable;
+
+	rc = kstrtoint_from_user(buf, len, 0, &val);
+	if (rc) {
+		wil_err(wil, "Invalid argument\n");
+		return rc;
+	}
+	if (val == 1)
+		/* default resolution */
+		val = 500;
+	if (val && (val < 50 || val > 1000)) {
+		wil_err(wil, "Invalid resolution %d\n", val);
+		return -EINVAL;
+	}
+
+	enable = !!val;
+	if (wil->tx_latency == enable)
+		return len;
+
+	wil_info(wil, "%s TX latency measurements (resolution %dusec)\n",
+		 enable ? "Enabling" : "Disabling", val);
+
+	if (enable) {
+		size_t sz = sizeof(u64) * WIL_NUM_LATENCY_BINS;
+
+		wil->tx_latency_res = val;
+		for (i = 0; i < ARRAY_SIZE(wil->sta); i++) {
+			struct wil_sta_info *sta = &wil->sta[i];
+
+			kfree(sta->tx_latency_bins);
+			sta->tx_latency_bins = kzalloc(sz, GFP_KERNEL);
+			if (!sta->tx_latency_bins)
+				return -ENOMEM;
+			sta->stats.tx_latency_min_us = U32_MAX;
+			sta->stats.tx_latency_max_us = 0;
+			sta->stats.tx_latency_total_us = 0;
+		}
+	}
+	wil->tx_latency = enable;
+
+	return len;
+}
+
+static const struct file_operations fops_tx_latency = {
+	.open		= wil_tx_latency_seq_open,
+	.release	= single_release,
+	.read		= seq_read,
+	.write		= wil_tx_latency_write,
+	.llseek		= seq_lseek,
+};
+
 static ssize_t wil_read_file_led_cfg(struct file *file, char __user *user_buf,
 				     size_t count, loff_t *ppos)
 {
@@ -2133,6 +2253,7 @@ static const struct {
 	{"srings",	0444,		&fops_srings},
 	{"status_msg",	0444,		&fops_status_msg},
 	{"rx_buff_mgmt",	0444,	&fops_rx_buff_mgmt},
+	{"tx_latency",	0644,		&fops_tx_latency},
 };
 
 static void wil6210_debugfs_init_files(struct wil6210_priv *wil,
@@ -2249,10 +2370,14 @@ int wil6210_debugfs_init(struct wil6210_priv *wil)
 
 void wil6210_debugfs_remove(struct wil6210_priv *wil)
 {
+	int i;
+
 	debugfs_remove_recursive(wil->debug);
 	wil->debug = NULL;
 
 	kfree(wil->dbg_data.data_arr);
+	for (i = 0; i < ARRAY_SIZE(wil->sta); i++)
+		kfree(wil->sta[i].tx_latency_bins);
 
 	/* free pmc memory without sending command to fw, as it will
 	 * be reset on the way down anyway