mac80211: implement chanctx reservation
In order to support channel switch with multiple vifs and multiple contexts, we implement a concept of channel context reservation. This allows us to reserve a channel context to be used later. The reservation functionality is not tied directly to channel switch and may be used in other situations (eg. reserving a channel context during IBSS join). We first check if an existing compatible context exists and if it does, we reserve it. If there is no compatible context we create a new one and reserve it. Additionally, split ieee80211_vif_copy_chanctx_to_vlans() so we can call it while already holding the chanctx mutex. Signed-off-by: Luciano Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Luciano Coelho
Johannes Berg
parent
77eeba974f
commit
11335a550b
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@ -426,6 +426,9 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
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ctx = container_of(conf, struct ieee80211_chanctx, conf);
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if (sdata->reserved_chanctx)
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ieee80211_vif_unreserve_chanctx(sdata);
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ieee80211_assign_vif_chanctx(sdata, NULL);
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if (ctx->refcount == 0)
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ieee80211_free_chanctx(local, ctx);
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@ -635,6 +638,166 @@ int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
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return ret;
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}
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static void
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__ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
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bool clear)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_sub_if_data *vlan;
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struct ieee80211_chanctx_conf *conf;
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if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
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return;
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lockdep_assert_held(&local->mtx);
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/* Check that conf exists, even when clearing this function
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* must be called with the AP's channel context still there
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* as it would otherwise cause VLANs to have an invalid
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* channel context pointer for a while, possibly pointing
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* to a channel context that has already been freed.
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*/
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conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
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lockdep_is_held(&local->chanctx_mtx));
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WARN_ON(!conf);
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if (clear)
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conf = NULL;
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list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
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rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
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}
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void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
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bool clear)
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{
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struct ieee80211_local *local = sdata->local;
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mutex_lock(&local->chanctx_mtx);
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__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
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mutex_unlock(&local->chanctx_mtx);
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}
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int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
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{
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lockdep_assert_held(&sdata->local->chanctx_mtx);
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if (WARN_ON(!sdata->reserved_chanctx))
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return -EINVAL;
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if (--sdata->reserved_chanctx->refcount == 0)
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ieee80211_free_chanctx(sdata->local, sdata->reserved_chanctx);
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sdata->reserved_chanctx = NULL;
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return 0;
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}
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int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
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const struct cfg80211_chan_def *chandef,
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enum ieee80211_chanctx_mode mode)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_chanctx_conf *conf;
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struct ieee80211_chanctx *new_ctx, *curr_ctx;
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int ret = 0;
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mutex_lock(&local->chanctx_mtx);
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conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
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lockdep_is_held(&local->chanctx_mtx));
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if (!conf) {
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ret = -EINVAL;
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goto out;
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}
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curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
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/* try to find another context with the chandef we want */
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new_ctx = ieee80211_find_chanctx(local, chandef, mode);
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if (!new_ctx) {
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/* create a new context */
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new_ctx = ieee80211_new_chanctx(local, chandef, mode);
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if (IS_ERR(new_ctx)) {
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ret = PTR_ERR(new_ctx);
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goto out;
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}
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}
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new_ctx->refcount++;
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sdata->reserved_chanctx = new_ctx;
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sdata->reserved_chandef = *chandef;
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out:
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mutex_unlock(&local->chanctx_mtx);
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return ret;
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}
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int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
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u32 *changed)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_chanctx *ctx;
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struct ieee80211_chanctx *old_ctx;
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struct ieee80211_chanctx_conf *conf;
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int ret;
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u32 tmp_changed = *changed;
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/* TODO: need to recheck if the chandef is usable etc.? */
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lockdep_assert_held(&local->mtx);
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mutex_lock(&local->chanctx_mtx);
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ctx = sdata->reserved_chanctx;
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if (WARN_ON(!ctx)) {
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ret = -EINVAL;
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goto out;
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}
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conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
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lockdep_is_held(&local->chanctx_mtx));
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if (!conf) {
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ret = -EINVAL;
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goto out;
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}
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old_ctx = container_of(conf, struct ieee80211_chanctx, conf);
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if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
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tmp_changed |= BSS_CHANGED_BANDWIDTH;
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sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
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/* unref our reservation before assigning */
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ctx->refcount--;
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sdata->reserved_chanctx = NULL;
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ret = ieee80211_assign_vif_chanctx(sdata, ctx);
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if (old_ctx->refcount == 0)
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ieee80211_free_chanctx(local, old_ctx);
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if (ret) {
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/* if assign fails refcount stays the same */
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if (ctx->refcount == 0)
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ieee80211_free_chanctx(local, ctx);
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goto out;
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}
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if (sdata->vif.type == NL80211_IFTYPE_AP)
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__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
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*changed = tmp_changed;
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ieee80211_recalc_chanctx_chantype(local, ctx);
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ieee80211_recalc_smps_chanctx(local, ctx);
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ieee80211_recalc_radar_chanctx(local, ctx);
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ieee80211_recalc_chanctx_min_def(local, ctx);
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out:
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mutex_unlock(&local->chanctx_mtx);
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return ret;
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}
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int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
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const struct cfg80211_chan_def *chandef,
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u32 *changed)
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@ -714,40 +877,6 @@ void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
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mutex_unlock(&local->chanctx_mtx);
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}
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void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
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bool clear)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_sub_if_data *vlan;
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struct ieee80211_chanctx_conf *conf;
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lockdep_assert_held(&local->mtx);
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if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
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return;
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mutex_lock(&local->chanctx_mtx);
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/*
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* Check that conf exists, even when clearing this function
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* must be called with the AP's channel context still there
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* as it would otherwise cause VLANs to have an invalid
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* channel context pointer for a while, possibly pointing
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* to a channel context that has already been freed.
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*/
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conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
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lockdep_is_held(&local->chanctx_mtx));
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WARN_ON(!conf);
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if (clear)
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conf = NULL;
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list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
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rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
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mutex_unlock(&local->chanctx_mtx);
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}
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void ieee80211_iter_chan_contexts_atomic(
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struct ieee80211_hw *hw,
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void (*iter)(struct ieee80211_hw *hw,
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@ -756,6 +756,10 @@ struct ieee80211_sub_if_data {
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bool csa_radar_required;
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struct cfg80211_chan_def csa_chandef;
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/* context reservation -- protected with chanctx_mtx */
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struct ieee80211_chanctx *reserved_chanctx;
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struct cfg80211_chan_def reserved_chandef;
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/* used to reconfigure hardware SM PS */
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struct work_struct recalc_smps;
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@ -1770,6 +1774,15 @@ int __must_check
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ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
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const struct cfg80211_chan_def *chandef,
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enum ieee80211_chanctx_mode mode);
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int __must_check
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ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
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const struct cfg80211_chan_def *chandef,
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enum ieee80211_chanctx_mode mode);
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int __must_check
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ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
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u32 *changed);
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int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata);
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int __must_check
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ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
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const struct cfg80211_chan_def *chandef,
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