iwlwifi: allocate 128 bytes linear buffer for rx skb

Allocate 128 bytes linear buffer for rx skb. The first 64 bytes is
reserved for mac80211 usage (for radiotap header expansion, etc).
The frame header starts from the second 64 bytes.

Cc: Johannes Berg <johannes@sipsolutions.net>
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-3945.c

@@ -564,7 +564,7 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 		return;
 	}
 
-	skb = alloc_skb(IWL_LINK_HDR_MAX, GFP_ATOMIC);
+	skb = alloc_skb(IWL_LINK_HDR_MAX * 2, GFP_ATOMIC);
 	if (!skb) {
 		IWL_ERR(priv, "alloc_skb failed\n");
 		return;
@@ -575,6 +575,7 @@ static void iwl3945_pass_packet_to_mac80211(struct iwl_priv *priv,
 				       (struct ieee80211_hdr *)rxb_addr(rxb),
 				       le32_to_cpu(rx_end->status), stats);
 
+	skb_reserve(skb, IWL_LINK_HDR_MAX);
 	skb_add_rx_frag(skb, 0, rxb->page,
 			(void *)rx_hdr->payload - (void *)pkt, len);
 

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

@@ -937,12 +937,13 @@ static void iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
 	    iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
 		return;
 
-	skb = alloc_skb(IWL_LINK_HDR_MAX, GFP_ATOMIC);
+	skb = alloc_skb(IWL_LINK_HDR_MAX * 2, GFP_ATOMIC);
 	if (!skb) {
 		IWL_ERR(priv, "alloc_skb failed\n");
 		return;
 	}
 
+	skb_reserve(skb, IWL_LINK_HDR_MAX);
 	skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
 
 	/* mac80211 currently doesn't support paged SKB. Convert it to