mac80211: add TX fastpath

In order to speed up mac80211's TX path, add the "fast-xmit" cache
that will cache the data frame 802.11 header and other data to be
able to build the frame more quickly. This cache is rebuilt when
external triggers imply changes, but a lot of the checks done per
packet today are simplified away to the check for the cache.

There's also a more detailed description in the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 265e42721a66..4aa5e893cbaa 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -137,6 +137,9 @@ static int ieee80211_set_noack_map(struct wiphy *wiphy,
         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
         sdata->noack_map = noack_map;
+
+        ieee80211_check_fast_xmit_iface(sdata);
+
         return 0;
 }
 
@@ -2099,10 +2102,14 @@ static int ieee80211_set_wiphy_params(struct wiphy *wiphy, u32 changed)
         int err;
 
         if (changed & WIPHY_PARAM_FRAG_THRESHOLD) {
+                ieee80211_check_fast_xmit_all(local);
+
                 err = drv_set_frag_threshold(local, wiphy->frag_threshold);
 
-                if (err)
+                if (err) {
+                        ieee80211_check_fast_xmit_all(local);
                         return err;
+                }
         }
 
         if ((changed & WIPHY_PARAM_COVERAGE_CLASS) ||