mac80211: add max channel calculation utility function

The utility function has no uses yet. It is aimed
at future chanctx reservation management and
channel switching.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3dd2111..bfc3ca5 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1822,6 +1822,7 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
                                 const struct cfg80211_chan_def *chandef,
                                 enum ieee80211_chanctx_mode chanmode,
                                 u8 radar_detect);
+int ieee80211_max_num_channels(struct ieee80211_local *local);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 5a6cc33..7a376f8 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2873,3 +2873,45 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
                                           num_different_channels,
                                           radar_detect, num);
 }
+
+static void
+ieee80211_iter_max_chans(const struct ieee80211_iface_combination *c,
+                        void *data)
+{
+       u32 *max_num_different_channels = data;
+
+       *max_num_different_channels = max(*max_num_different_channels,
+                                         c->num_different_channels);
+}
+
+int ieee80211_max_num_channels(struct ieee80211_local *local)
+{
+       struct ieee80211_sub_if_data *sdata;
+       int num[NUM_NL80211_IFTYPES] = {};
+       struct ieee80211_chanctx *ctx;
+       int num_different_channels = 0;
+       u8 radar_detect = 0;
+       u32 max_num_different_channels = 1;
+       int err;
+
+       lockdep_assert_held(&local->chanctx_mtx);
+
+       list_for_each_entry(ctx, &local->chanctx_list, list) {
+               num_different_channels++;
+
+               if (ctx->conf.radar_enabled)
+                       radar_detect |= BIT(ctx->conf.def.width);
+       }
+
+       list_for_each_entry_rcu(sdata, &local->interfaces, list)
+               num[sdata->wdev.iftype]++;
+
+       err = cfg80211_iter_combinations(local->hw.wiphy,
+                                        num_different_channels, radar_detect,
+                                        num, ieee80211_iter_max_chans,
+                                        &max_num_different_channels);
+       if (err < 0)
+               return err;
+
+       return max_num_different_channels;
+}