mac80211: round IEEE80211_TX_STATUS_HEADROOM up to multiple of 4

[ Upstream commit 651b9920d7a694ffb1f885aef2bbb068a25d9d66 ]

This ensures that mac80211 allocated management frames are properly
aligned, which makes copying them more efficient.
For instance, mt76 uses iowrite32_copy to copy beacon frames to beacon
template memory on the chip.
Misaligned 32-bit accesses cause CPU exceptions on MIPS and should be
avoided.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 7a49a31..ec11cb1 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3898,7 +3898,7 @@ static inline int ieee80211_sta_ps_transition_ni(struct ieee80211_sta *sta,
  * The TX headroom reserved by mac80211 for its own tx_status functions.
  * This is enough for the radiotap header.
  */
-#define IEEE80211_TX_STATUS_HEADROOM   14
+#define IEEE80211_TX_STATUS_HEADROOM   ALIGN(14, 4)
 
 /**
  * ieee80211_sta_set_buffered - inform mac80211 about driver-buffered frames