cfg80211: mark ieee80211_hdrlen const
This function analyses only its single, value-passed
argument, and has no side effects. Thus it can be
const, which makes mac80211 smaller, for example:
text data bss dec hex filename
362518 16720 884 380122 5ccda mac80211.ko (before)
362358 16720 884 379962 5cc3a mac80211.ko (after)
a 160 byte saving in text size, and an optimisation
because the function won't be called as often.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 2fd06c6..2b403c7 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1715,7 +1715,7 @@
* ieee80211_hdrlen - get header length in bytes from frame control
* @fc: frame control field in little-endian format
*/
-unsigned int ieee80211_hdrlen(__le16 fc);
+unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc);
/**
* ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 0c8a1e8..1eb2416 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -221,7 +221,7 @@
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
EXPORT_SYMBOL(bridge_tunnel_header);
-unsigned int ieee80211_hdrlen(__le16 fc)
+unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc)
{
unsigned int hdrlen = 24;