mac80211: support paged rx SKBs

Mac80211 drivers can now pass paged SKBs to mac80211 via
ieee80211_rx{_irqsafe}. The implementation currently use
skb_linearize() in a few places i.e. management frame
handling, software decryption, defragmentation and A-MSDU
process. We will optimize them one by one later.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Cc: Kalle Valo <kalle.valo@iki.fi>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 1a8f50af49a0..ecaae10426f9 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1822,7 +1822,10 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw);
  * ieee80211_rx - receive frame
  *
  * Use this function to hand received frames to mac80211. The receive
- * buffer in @skb must start with an IEEE 802.11 header.
+ * buffer in @skb must start with an IEEE 802.11 header. In case of a
+ * paged @skb is used, the driver is recommended to put the ieee80211
+ * header of the frame on the linear part of the @skb to avoid memory
+ * allocation and/or memcpy by the stack.
  *
  * This function may not be called in IRQ context. Calls to this function
  * for a single hardware must be synchronized against each other. Calls to