rt2x00: Add support for L2 padding during TX/RX

Some hardware require L2 padding between header and payload
because both must be aligned to a 4-byte boundary. This hardware
also is easier during the RX path since we no longer need to
move the entire payload but rather only the header to remove
the padding (mac80211 only wants the payload to be 4-byte aligned).

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 5752aaae906b..e15086af7278 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -227,6 +227,7 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 	enum data_queue_qid qid = skb_get_queue_mapping(entry->skb);
+	unsigned int header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
 	u8 rate_idx, rate_flags;
 
 	/*
@@ -235,13 +236,19 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	rt2x00queue_unmap_skb(rt2x00dev, entry->skb);
 
 	/*
+	 * Remove L2 padding which was added during
+	 */
+	if (test_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags))
+		rt2x00queue_payload_align(entry->skb, true, header_length);
+
+	/*
 	 * If the IV/EIV data was stripped from the frame before it was
 	 * passed to the hardware, we should now reinsert it again because
 	 * mac80211 will expect the the same data to be present it the
 	 * frame as it was passed to us.
 	 */
 	if (test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags))
-		rt2x00crypto_tx_insert_iv(entry->skb);
+		rt2x00crypto_tx_insert_iv(entry->skb, header_length);
 
 	/*
 	 * Send frame to debugfs immediately, after this call is completed
@@ -325,7 +332,7 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 	struct ieee80211_supported_band *sband;
 	const struct rt2x00_rate *rate;
 	unsigned int header_length;
-	unsigned int align;
+	bool l2pad;
 	unsigned int i;
 	int idx = -1;
 
@@ -348,12 +355,15 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 	memset(&rxdesc, 0, sizeof(rxdesc));
 	rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);
 
+	/* Trim buffer to correct size */
+	skb_trim(entry->skb, rxdesc.size);
+
 	/*
 	 * The data behind the ieee80211 header must be
 	 * aligned on a 4 byte boundary.
 	 */
 	header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
-	align = ((unsigned long)(entry->skb->data + header_length)) & 3;
+	l2pad = !!(rxdesc.dev_flags & RXDONE_L2PAD);
 
 	/*
 	 * Hardware might have stripped the IV/EIV/ICV data,
@@ -362,18 +372,11 @@ void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
 	 * in which case we should reinsert the data into the frame.
 	 */
 	if ((rxdesc.dev_flags & RXDONE_CRYPTO_IV) &&
-	    (rxdesc.flags & RX_FLAG_IV_STRIPPED)) {
-		rt2x00crypto_rx_insert_iv(entry->skb, align,
-					  header_length, &rxdesc);
-	} else if (align) {
-		skb_push(entry->skb, align);
-		/* Move entire frame in 1 command */
-		memmove(entry->skb->data, entry->skb->data + align,
-			rxdesc.size);
-	}
-
-	/* Update data pointers, trim buffer to correct size */
-	skb_trim(entry->skb, rxdesc.size);
+	    (rxdesc.flags & RX_FLAG_IV_STRIPPED))
+		rt2x00crypto_rx_insert_iv(entry->skb, l2pad, header_length,
+					  &rxdesc);
+	else
+		rt2x00queue_payload_align(entry->skb, l2pad, header_length);
 
 	/*
 	 * Update RX statistics.