mac80211: implement multi-vif in-place reservations

Multi-vif in-place reservations happen when
it is impossible to allocate more channel contexts
as indicated by interface combinations.

Such reservations are not finalized until all
assigned interfaces are ready.

This still doesn't handle all possible cases
(i.e. degradation of number of channels) properly.

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

1 files changed, 8 insertions, 1 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e31458201278..1b42aa16ec03 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1698,7 +1698,9 @@ int ieee80211_reconfig(struct ieee80211_local *local)
         if (local->use_chanctx) {
                 mutex_lock(&local->chanctx_mtx);
                 list_for_each_entry(ctx, &local->chanctx_list, list)
-                        WARN_ON(drv_add_chanctx(local, ctx));
+                        if (ctx->replace_state !=
+                            IEEE80211_CHANCTX_REPLACES_OTHER)
+                                WARN_ON(drv_add_chanctx(local, ctx));
                 mutex_unlock(&local->chanctx_mtx);
 
                 list_for_each_entry(sdata, &local->interfaces, list) {
@@ -2972,6 +2974,8 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
                 num[iftype] = 1;
 
         list_for_each_entry(ctx, &local->chanctx_list, list) {
+                if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
+                        continue;
                 if (ctx->conf.radar_enabled)
                         radar_detect |= BIT(ctx->conf.def.width);
                 if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) {
@@ -3030,6 +3034,9 @@ int ieee80211_max_num_channels(struct ieee80211_local *local)
         lockdep_assert_held(&local->chanctx_mtx);
 
         list_for_each_entry(ctx, &local->chanctx_list, list) {
+                if (ctx->replace_state == IEEE80211_CHANCTX_WILL_BE_REPLACED)
+                        continue;
+
                 num_different_channels++;
 
                 if (ctx->conf.radar_enabled)