ath11k: Add support for ring backpressure stats

Add support for collecting and dumping the ring backpressure
stats via debugfs. Stats are dumped only if events are
received for the specific ring.

Below command can be used to obtain these stats as part of soc dp stats.
cat /sys/kernel/debug/ath11k/ipq8074/soc_dp_stats

 Sample Output - When No stats available:

 Backpressure Stats
 ==================
 No Ring Backpressure stats received

 Sample Output -  When ring bp stats available for specific ring

 Backpressure Stats
 ==================
 Ring: REO2SW1_RING
 count: 1
 hp: 2
 tp: 2
 seen before: 4ms

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.1.0.1-01213-QCAHKSWPL_SILICONZ-1

Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1591768308-32005-3-git-send-email-srirrama@codeaurora.org

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath11k/debug.c b/drivers/net/wireless/ath/ath11k/debug.c
index 647d5a50043f..62a1aa0565a9 100644
--- a/drivers/net/wireless/ath/ath11k/debug.c
+++ b/drivers/net/wireless/ath/ath11k/debug.c
@@ -12,6 +12,43 @@
 #include "debug_htt_stats.h"
 #include "peer.h"
 
+static const char *htt_bp_umac_ring[HTT_SW_UMAC_RING_IDX_MAX] = {
+	"REO2SW1_RING",
+	"REO2SW2_RING",
+	"REO2SW3_RING",
+	"REO2SW4_RING",
+	"WBM2REO_LINK_RING",
+	"REO2TCL_RING",
+	"REO2FW_RING",
+	"RELEASE_RING",
+	"PPE_RELEASE_RING",
+	"TCL2TQM_RING",
+	"TQM_RELEASE_RING",
+	"REO_RELEASE_RING",
+	"WBM2SW0_RELEASE_RING",
+	"WBM2SW1_RELEASE_RING",
+	"WBM2SW2_RELEASE_RING",
+	"WBM2SW3_RELEASE_RING",
+	"REO_CMD_RING",
+	"REO_STATUS_RING",
+};
+
+static const char *htt_bp_lmac_ring[HTT_SW_LMAC_RING_IDX_MAX] = {
+	"FW2RXDMA_BUF_RING",
+	"FW2RXDMA_STATUS_RING",
+	"FW2RXDMA_LINK_RING",
+	"SW2RXDMA_BUF_RING",
+	"WBM2RXDMA_LINK_RING",
+	"RXDMA2FW_RING",
+	"RXDMA2SW_RING",
+	"RXDMA2RELEASE_RING",
+	"RXDMA2REO_RING",
+	"MONITOR_STATUS_RING",
+	"MONITOR_BUF_RING",
+	"MONITOR_DESC_RING",
+	"MONITOR_DEST_RING",
+};
+
 void ath11k_info(struct ath11k_base *ab, const char *fmt, ...)
 {
 	struct va_format vaf = {
@@ -739,6 +776,72 @@ static const struct file_operations fops_extd_rx_stats = {
 	.open = simple_open,
 };
 
+static int ath11k_fill_bp_stats(struct ath11k_base *ab,
+				struct ath11k_bp_stats *bp_stats,
+				char *buf, int len, int size)
+{
+	lockdep_assert_held(&ab->base_lock);
+
+	len += scnprintf(buf + len, size - len, "count: %u\n",
+			 bp_stats->count);
+	len += scnprintf(buf + len, size - len, "hp: %u\n",
+			 bp_stats->hp);
+	len += scnprintf(buf + len, size - len, "tp: %u\n",
+			 bp_stats->tp);
+	len += scnprintf(buf + len, size - len, "seen before: %ums\n\n",
+			 jiffies_to_msecs(jiffies - bp_stats->jiffies));
+	return len;
+}
+
+static ssize_t ath11k_debug_dump_soc_ring_bp_stats(struct ath11k_base *ab,
+						   char *buf, int size)
+{
+	struct ath11k_bp_stats *bp_stats;
+	bool stats_rxd = false;
+	u8 i, pdev_idx;
+	int len = 0;
+
+	len += scnprintf(buf + len, size - len, "\nBackpressure Stats\n");
+	len += scnprintf(buf + len, size - len, "==================\n");
+
+	spin_lock_bh(&ab->base_lock);
+	for (i = 0; i < HTT_SW_UMAC_RING_IDX_MAX; i++) {
+		bp_stats = &ab->soc_stats.bp_stats.umac_ring_bp_stats[i];
+
+		if (!bp_stats->count)
+			continue;
+
+		len += scnprintf(buf + len, size - len, "Ring: %s\n",
+				 htt_bp_umac_ring[i]);
+		len = ath11k_fill_bp_stats(ab, bp_stats, buf, len, size);
+		stats_rxd = true;
+	}
+
+	for (i = 0; i < HTT_SW_LMAC_RING_IDX_MAX; i++) {
+		for (pdev_idx = 0; pdev_idx < MAX_RADIOS; pdev_idx++) {
+			bp_stats =
+				&ab->soc_stats.bp_stats.lmac_ring_bp_stats[i][pdev_idx];
+
+			if (!bp_stats->count)
+				continue;
+
+			len += scnprintf(buf + len, size - len, "Ring: %s\n",
+					 htt_bp_lmac_ring[i]);
+			len += scnprintf(buf + len, size - len, "pdev: %d\n",
+					 pdev_idx);
+			len = ath11k_fill_bp_stats(ab, bp_stats, buf, len, size);
+			stats_rxd = true;
+		}
+	}
+	spin_unlock_bh(&ab->base_lock);
+
+	if (!stats_rxd)
+		len += scnprintf(buf + len, size - len,
+				 "No Ring Backpressure stats received\n\n");
+
+	return len;
+}
+
 static ssize_t ath11k_debug_dump_soc_dp_stats(struct file *file,
 					      char __user *user_buf,
 					      size_t count, loff_t *ppos)
@@ -799,6 +902,8 @@ static ssize_t ath11k_debug_dump_soc_dp_stats(struct file *file,
 			 "\nMisc Transmit Failures: %d\n",
 			 atomic_read(&soc_stats->tx_err.misc_fail));
 
+	len += ath11k_debug_dump_soc_ring_bp_stats(ab, buf + len, size - len);
+
 	if (len > size)
 		len = size;
 	retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);