iwlwifi: new debugging feature for dumping data traffic

The traffic buffer will only beallocated and used if either bit 23
(IWL_DX_TX) or bit 24 (IWL_DL_RX) of "debug" is set;
example: "debug=0x800000" - log tx data traffic
         "debug=0x1000000" - log rx data traffic
         "debug=0x1800000" - log both tx and rx traffic

The traffic log will store the beginning portion (64 bytes)  of the
latest 256 of tx and rx packets in the round-robbin buffer for
debugging,
user can examine the log through debugfs file.

How to display the current logged tx/rx traffic and txfifo and rxfifo
read/write point:
"cat traffic_log" in /sys/kernel/debug/ieee80211/phy0/iwlagn/debug
directory

By echo "0" to traffic_log file will empty the traffic log buffer and
reset both tx and rx taffic log index to 0.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 100 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 5315d347a004..1ae2ce3512c3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -2953,6 +2953,106 @@ void iwl_mac_reset_tsf(struct ieee80211_hw *hw)
 }
 EXPORT_SYMBOL(iwl_mac_reset_tsf);
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+
+#define IWL_TRAFFIC_DUMP_SIZE	(IWL_TRAFFIC_ENTRY_SIZE * IWL_TRAFFIC_ENTRIES)
+
+void iwl_reset_traffic_log(struct iwl_priv *priv)
+{
+	priv->tx_traffic_idx = 0;
+	priv->rx_traffic_idx = 0;
+	if (priv->tx_traffic)
+		memset(priv->tx_traffic, 0, IWL_TRAFFIC_DUMP_SIZE);
+	if (priv->rx_traffic)
+		memset(priv->rx_traffic, 0, IWL_TRAFFIC_DUMP_SIZE);
+}
+
+int iwl_alloc_traffic_mem(struct iwl_priv *priv)
+{
+	u32 traffic_size = IWL_TRAFFIC_DUMP_SIZE;
+
+	if (iwl_debug_level & IWL_DL_TX) {
+		if (!priv->tx_traffic) {
+			priv->tx_traffic =
+				kzalloc(traffic_size, GFP_KERNEL);
+			if (!priv->tx_traffic)
+				return -ENOMEM;
+		}
+	}
+	if (iwl_debug_level & IWL_DL_RX) {
+		if (!priv->rx_traffic) {
+			priv->rx_traffic =
+				kzalloc(traffic_size, GFP_KERNEL);
+			if (!priv->rx_traffic)
+				return -ENOMEM;
+		}
+	}
+	iwl_reset_traffic_log(priv);
+	return 0;
+}
+EXPORT_SYMBOL(iwl_alloc_traffic_mem);
+
+void iwl_free_traffic_mem(struct iwl_priv *priv)
+{
+	kfree(priv->tx_traffic);
+	priv->tx_traffic = NULL;
+
+	kfree(priv->rx_traffic);
+	priv->rx_traffic = NULL;
+}
+EXPORT_SYMBOL(iwl_free_traffic_mem);
+
+void iwl_dbg_log_tx_data_frame(struct iwl_priv *priv,
+		      u16 length, struct ieee80211_hdr *header)
+{
+	__le16 fc;
+	u16 len;
+
+	if (likely(!(iwl_debug_level & IWL_DL_TX)))
+		return;
+
+	if (!priv->tx_traffic)
+		return;
+
+	fc = header->frame_control;
+	if (ieee80211_is_data(fc)) {
+		len = (length > IWL_TRAFFIC_ENTRY_SIZE)
+		       ? IWL_TRAFFIC_ENTRY_SIZE : length;
+		memcpy((priv->tx_traffic +
+		       (priv->tx_traffic_idx * IWL_TRAFFIC_ENTRY_SIZE)),
+		       header, len);
+		priv->tx_traffic_idx =
+			(priv->tx_traffic_idx + 1) % IWL_TRAFFIC_ENTRIES;
+	}
+}
+EXPORT_SYMBOL(iwl_dbg_log_tx_data_frame);
+
+void iwl_dbg_log_rx_data_frame(struct iwl_priv *priv,
+		      u16 length, struct ieee80211_hdr *header)
+{
+	__le16 fc;
+	u16 len;
+
+	if (likely(!(iwl_debug_level & IWL_DL_RX)))
+		return;
+
+	if (!priv->rx_traffic)
+		return;
+
+	fc = header->frame_control;
+	if (ieee80211_is_data(fc)) {
+		len = (length > IWL_TRAFFIC_ENTRY_SIZE)
+		       ? IWL_TRAFFIC_ENTRY_SIZE : length;
+		memcpy((priv->rx_traffic +
+		       (priv->rx_traffic_idx * IWL_TRAFFIC_ENTRY_SIZE)),
+		       header, len);
+		priv->rx_traffic_idx =
+			(priv->rx_traffic_idx + 1) % IWL_TRAFFIC_ENTRIES;
+	}
+}
+EXPORT_SYMBOL(iwl_dbg_log_rx_data_frame);
+#endif
+
 #ifdef CONFIG_PM
 
 int iwl_pci_suspend(struct pci_dev *pdev, pm_message_t state)