cw1200: throughput optimization and fine-tuning.

 * Fixed: Do not allocate a dedicated communication channel (buffer) for WSM command stream,
   use it for data traffic when needed.
 * Additional statistics added to DebugFS: counters for TX policy cache misses and unaligned
   skbs memmove.
 * Fixed: Strip IV/ICV in the driver to prevent mac80211 layer from double-verification.

Change-Id: I600664466d577df4c2bc62ff49fb22f2d3b024cc
Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/24482
Reviewed-by: Robert MARKLUND <robert.marklund@stericsson.com>
Tested-by: Robert MARKLUND <robert.marklund@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/25622
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>

4 files changed, 78 insertions, 15 deletions

diff --git a/drivers/staging/cw1200/bh.c b/drivers/staging/cw1200/bh.c
index 177274a00d2..d49f9fdf732 100644
--- a/drivers/staging/cw1200/bh.c
+++ b/drivers/staging/cw1200/bh.c
@@ -120,7 +120,7 @@ int wsm_release_tx_buffer(struct cw1200_common *priv, int count)
 	priv->hw_bufs_used -= count;
 	if (WARN_ON(priv->hw_bufs_used < 0))
 		ret = -1;
-	else if (hw_bufs_used >= priv->wsm_caps.numInpChBufs - 1)
+	else if (hw_bufs_used >= priv->wsm_caps.numInpChBufs)
 		ret = 1;
 	if (!priv->hw_bufs_used)
 		wake_up_interruptible(&priv->hw_bufs_used_wq);
@@ -363,9 +363,7 @@ tx:
 		/* HACK! One buffer is reserved for control path */
 		BUG_ON(priv->hw_bufs_used > priv->wsm_caps.numInpChBufs);
 		tx_allowed =
-			priv->hw_bufs_used + 1 < priv->wsm_caps.numInpChBufs;
-		if (unlikely(!tx_allowed && priv->wsm_cmd.ptr))
-			tx_allowed = 1;
+			priv->hw_bufs_used < priv->wsm_caps.numInpChBufs;
 
 		if (tx && tx_allowed) {
 			size_t tx_len;
diff --git a/drivers/staging/cw1200/debug.c b/drivers/staging/cw1200/debug.c
index b4c2da23135..13c4570372f 100644
--- a/drivers/staging/cw1200/debug.c
+++ b/drivers/staging/cw1200/debug.c
@@ -253,7 +253,10 @@ static int cw1200_status_show(struct seq_file *seq, void *v)
 		d->rx);
 	seq_printf(seq, "AGG RXed:   %d\n",
 		d->rx_agg);
-
+	seq_printf(seq, "TX miss:    %d\n",
+		d->tx_cache_miss);
+	seq_printf(seq, "TX copy:    %d\n",
+		d->tx_copy);
 	seq_printf(seq, "Scan:       %s\n",
 		atomic_read(&priv->scan.in_progress) ? "active" : "idle");
 	seq_printf(seq, "Led state:  0x%.2X\n",
diff --git a/drivers/staging/cw1200/debug.h b/drivers/staging/cw1200/debug.h
index a19083a49b9..e7fc4d2daef 100644
--- a/drivers/staging/cw1200/debug.h
+++ b/drivers/staging/cw1200/debug.h
@@ -13,6 +13,8 @@ struct cw1200_debug_priv {
 	int rx_agg;
 	int tx_multi;
 	int tx_multi_frames;
+	int tx_cache_miss;
+	int tx_copy;
 };
 
 int cw1200_debug_init(struct cw1200_common *priv);
@@ -45,6 +47,16 @@ static inline void cw1200_debug_rxed_agg(struct cw1200_common *priv)
 	++priv->debug->rx_agg;
 }
 
+static inline void cw1200_debug_tx_cache_miss(struct cw1200_common *priv)
+{
+	++priv->debug->tx_cache_miss;
+}
+
+static inline void cw1200_debug_tx_copy(struct cw1200_common *priv)
+{
+	++priv->debug->tx_copy;
+}
+
 #else /* CONFIG_CW1200_DEBUGFS */
 
 static inline int cw1200_debug_init(struct cw1200_common *priv)
@@ -77,6 +89,14 @@ static inline void cw1200_debug_rxed_agg(struct cw1200_common *priv)
 {
 }
 
+static inline void cw1200_debug_tx_cache_miss(struct cw1200_common *priv)
+{
+}
+
+static inline void cw1200_debug_tx_copy(struct cw1200_common *priv)
+{
+}
+
 #endif /* CONFIG_CW1200_DEBUGFS */
 
 #endif /* CW1200_DEBUG_H_INCLUDED */
diff --git a/drivers/staging/cw1200/txrx.c b/drivers/staging/cw1200/txrx.c
index eb2802af318..8616d1d2ffe 100644
--- a/drivers/staging/cw1200/txrx.c
+++ b/drivers/staging/cw1200/txrx.c
@@ -323,6 +323,7 @@ static int tx_policy_upload(struct cw1200_common *priv)
 		}
 	}
 	spin_unlock_bh(&cache->lock);
+	cw1200_debug_tx_cache_miss(priv);
 	tx_policy_printk(KERN_DEBUG "[TX policy] Upload %d policies\n",
 				arg.hdr.numTxRatePolicies);
 	return wsm_set_tx_rate_retry_policy(priv, &arg);
@@ -501,6 +502,7 @@ int cw1200_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 		p = skb_push(skb, offset);
 		memmove(p, &p[offset], skb->len - offset);
 		skb_trim(skb, skb->len - offset);
+		cw1200_debug_tx_copy(priv);
 	}
 
 	if (ieee80211_is_action(hdr->frame_control))
@@ -647,7 +649,7 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 
 	if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED)) {
 		/* STA is stopped. */
-		return;
+		goto drop;
 	}
 
 	if (unlikely(arg->status)) {
@@ -656,17 +658,18 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 			hdr->flag |= RX_FLAG_MMIC_ERROR;
 		} else if (arg->status == WSM_STATUS_NO_KEY_FOUND) {
 			txrx_printk(KERN_DEBUG "[RX] No key found.\n");
-			return;
+			goto drop;
 		} else {
 			txrx_printk(KERN_DEBUG "[RX] Receive failure: %d.\n",
 				arg->status);
-			return;
+			goto drop;
 		}
 	}
 
 	if (skb->len < sizeof(struct ieee80211_hdr_3addr)) {
-		wiphy_warn(priv->hw->wiphy, "Mailformed SDU rx'ed.\n");
-		return;
+		wiphy_warn(priv->hw->wiphy, "Mailformed SDU rx'ed. "
+				"Size is lesser than IEEE header.\n");
+		goto drop;
 	}
 
 	frame_control = *(__le16*)skb->data;
@@ -691,13 +694,47 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 	hdr->antenna = 0;
 
 	if (WSM_RX_STATUS_ENCRYPTION(arg->flags)) {
-		hdr->flag |= RX_FLAG_DECRYPTED;
-		if (!arg->status &&
-				(WSM_RX_STATUS_ENCRYPTION(arg->flags) ==
-				 WSM_RX_STATUS_TKIP)) {
+		size_t iv_len = 0, icv_len = 0;
+		size_t hdrlen = ieee80211_hdrlen(frame_control);
+
+		hdr->flag |= RX_FLAG_DECRYPTED | RX_FLAG_IV_STRIPPED;
+
+		/* Oops... There is no fast way to ask mac80211 about
+		 * IV/ICV lengths. Even defineas are not exposed.*/
+		switch (WSM_RX_STATUS_ENCRYPTION(arg->flags)) {
+		case WSM_RX_STATUS_WEP:
+			iv_len = 4 /* WEP_IV_LEN */;
+			icv_len = 4 /* WEP_ICV_LEN */;
+			break;
+		case WSM_RX_STATUS_TKIP:
+			iv_len = 8 /* TKIP_IV_LEN */;
+			icv_len = 4 /* TKIP_ICV_LEN */
+				+ 8 /*MICHAEL_MIC_LEN*/;
 			hdr->flag |= RX_FLAG_MMIC_STRIPPED;
-			skb_trim(skb, skb->len - 8 /*MICHAEL_MIC_LEN*/);
+			break;
+		case WSM_RX_STATUS_AES:
+			iv_len = 8 /* CCMP_HDR_LEN */;
+			icv_len = 8 /* CCMP_MIC_LEN */;
+			break;
+		case WSM_RX_STATUS_WAPI:
+			iv_len = 18 /* WAPI_HDR_LEN */;
+			icv_len = 16 /* WAPI_MIC_LEN */;
+			break;
+		default:
+			WARN_ON("Unknown encryption type");
+			goto drop;
 		}
+
+		if (skb->len < hdrlen + iv_len + icv_len) {
+			wiphy_warn(priv->hw->wiphy, "Mailformed SDU rx'ed. "
+				"Size is lesser than crypto headers.\n");
+			goto drop;
+		}
+
+		/* Remove IV, ICV and MIC */
+		skb_trim(skb, skb->len - icv_len);
+		memmove(skb->data + iv_len, skb->data, hdrlen);
+		skb_pull(skb, iv_len);
 	}
 
 	cw1200_debug_rxed(priv);
@@ -714,6 +751,11 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 	 * system performance. */
 	ieee80211_rx_irqsafe(priv->hw, skb);
 	*skb_p = NULL;
+	return;
+
+drop:
+	/* TODO: update failure counters */
+	return;
 }
 
 /* ******************************************************************** */