iwlwifi: format and show statistics counter from uCode

To help debug uCode related problem, adding "delta" and "max"
information in debugfs statistics counters display.

Those information show the delta between two statistics report from
uCode, user can monitor the counters for any "un-normal" behavior.
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Jay Sternberg<jay.e.sternberg@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-dev.h

@@ -1162,6 +1162,8 @@ struct iwl_priv {
 	struct iwl_notif_statistics statistics;
 #ifdef CONFIG_IWLWIFI_DEBUG
 	struct iwl_notif_statistics accum_statistics;
+	struct iwl_notif_statistics delta_statistics;
+	struct iwl_notif_statistics max_delta;
 #endif
 
 	/* context information */

drivers/net/wireless/iwlwifi/iwl-rx.c

@@ -564,15 +564,24 @@ static void iwl_accumulative_statistics(struct iwl_priv *priv,
 	int i;
 	__le32 *prev_stats;
 	u32 *accum_stats;
+	u32 *delta, *max_delta;
 
 	prev_stats = (__le32 *)&priv->statistics;
 	accum_stats = (u32 *)&priv->accum_statistics;
+	delta = (u32 *)&priv->delta_statistics;
+	max_delta = (u32 *)&priv->max_delta;
 
 	for (i = sizeof(__le32); i < sizeof(struct iwl_notif_statistics);
-	     i += sizeof(__le32), stats++, prev_stats++, accum_stats++)
-		if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats))
-			*accum_stats += (le32_to_cpu(*stats) -
+	     i += sizeof(__le32), stats++, prev_stats++, delta++,
+	     max_delta++, accum_stats++) {
+		if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats)) {
+			*delta = (le32_to_cpu(*stats) -
 				le32_to_cpu(*prev_stats));
+			*accum_stats += *delta;
+			if (*delta > *max_delta)
+				*max_delta = *delta;
+		}
+	}
 
 	/* reset accumulative statistics for "no-counter" type statistics */
 	priv->accum_statistics.general.temperature =
@@ -641,6 +650,10 @@ void iwl_reply_statistics(struct iwl_priv *priv,
 #ifdef CONFIG_IWLWIFI_DEBUG
 		memset(&priv->accum_statistics, 0,
 			sizeof(struct iwl_notif_statistics));
+		memset(&priv->delta_statistics, 0,
+			sizeof(struct iwl_notif_statistics));
+		memset(&priv->max_delta, 0,
+			sizeof(struct iwl_notif_statistics));
 #endif
 		IWL_DEBUG_RX(priv, "Statistics have been cleared\n");
 	}