mac80211: use channel contexts

Instead of operating on a single channel only,
use the new channel context infrastructure in
all mac80211 code.

This enables drivers that want to use the new
channel context infrastructure to use multiple
channels, while nothing should change for all
the other drivers that don't support it.

Right now this disables both TX power settings
and spatial multiplexing powersave. Both need
to be re-enabled on a channel context basis.

Additionally, when channel contexts are used
drop the connection when channel switch is
received rather than trying to handle it. This
will have to be improved later.

[With fixes from Eliad and Emmanuel incorporated]
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 86 insertions, 43 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e714ed8bb198..4add50063161 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -178,20 +178,30 @@ static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
 {
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_supported_band *sband;
+        struct ieee80211_chanctx_conf *chanctx_conf;
+        struct ieee80211_channel *chan;
         struct sta_info *sta;
         u32 changed = 0;
         u16 ht_opmode;
         bool disable_40 = false;
 
-        sband = local->hw.wiphy->bands[local->oper_channel->band];
+        rcu_read_lock();
+        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+        if (WARN_ON(!chanctx_conf)) {
+                rcu_read_unlock();
+                return 0;
+        }
+        chan = chanctx_conf->channel;
+        rcu_read_unlock();
+        sband = local->hw.wiphy->bands[chan->band];
 
         switch (sdata->vif.bss_conf.channel_type) {
         case NL80211_CHAN_HT40PLUS:
-                if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40PLUS)
+                if (chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
                         disable_40 = true;
                 break;
         case NL80211_CHAN_HT40MINUS:
-                if (local->oper_channel->flags & IEEE80211_CHAN_NO_HT40MINUS)
+                if (chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
                         disable_40 = true;
                 break;
         default:
@@ -359,11 +369,21 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
         int i, count, rates_len, supp_rates_len;
         u16 capab;
         struct ieee80211_supported_band *sband;
+        struct ieee80211_chanctx_conf *chanctx_conf;
+        struct ieee80211_channel *chan;
         u32 rates = 0;
 
         lockdep_assert_held(&ifmgd->mtx);
 
-        sband = local->hw.wiphy->bands[local->oper_channel->band];
+        rcu_read_lock();
+        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+        if (WARN_ON(!chanctx_conf)) {
+                rcu_read_unlock();
+                return;
+        }
+        chan = chanctx_conf->channel;
+        rcu_read_unlock();
+        sband = local->hw.wiphy->bands[chan->band];
 
         if (assoc_data->supp_rates_len) {
                 /*
@@ -485,7 +505,7 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
                 *pos++ = WLAN_EID_PWR_CAPABILITY;
                 *pos++ = 2;
                 *pos++ = 0; /* min tx power */
-                *pos++ = local->oper_channel->max_power; /* max tx power */
+                *pos++ = chan->max_power; /* max tx power */
 
                 /* 2. supported channels */
                 /* TODO: get this in reg domain format */
@@ -523,7 +543,7 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 
         if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                 ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
-                                    sband, local->oper_channel, ifmgd->ap_smps);
+                                    sband, chan, ifmgd->ap_smps);
 
         if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                 ieee80211_add_vht_ie(sdata, skb, sband);
@@ -657,18 +677,18 @@ static void ieee80211_chswitch_work(struct work_struct *work)
         if (!ifmgd->associated)
                 goto out;
 
-        sdata->local->oper_channel = sdata->local->csa_channel;
+        sdata->local->_oper_channel = sdata->local->csa_channel;
         if (!sdata->local->ops->channel_switch) {
                 /* call "hw_config" only if doing sw channel switch */
                 ieee80211_hw_config(sdata->local,
                         IEEE80211_CONF_CHANGE_CHANNEL);
         } else {
                 /* update the device channel directly */
-                sdata->local->hw.conf.channel = sdata->local->oper_channel;
+                sdata->local->hw.conf.channel = sdata->local->_oper_channel;
         }
 
         /* XXX: shouldn't really modify cfg80211-owned data! */
-        ifmgd->associated->channel = sdata->local->oper_channel;
+        ifmgd->associated->channel = sdata->local->_oper_channel;
 
         /* XXX: wait for a beacon first? */
         ieee80211_wake_queues_by_reason(&sdata->local->hw,
@@ -680,11 +700,8 @@ static void ieee80211_chswitch_work(struct work_struct *work)
 
 void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
 {
-        struct ieee80211_sub_if_data *sdata;
-        struct ieee80211_if_managed *ifmgd;
-
-        sdata = vif_to_sdata(vif);
-        ifmgd = &sdata->u.mgd;
+        struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 
         trace_api_chswitch_done(sdata, success);
         if (!success) {
@@ -723,6 +740,7 @@ void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
         int new_freq = ieee80211_channel_to_frequency(sw_elem->new_ch_num,
                                                       cbss->channel->band);
+        struct ieee80211_chanctx *chanctx;
 
         ASSERT_MGD_MTX(ifmgd);
 
@@ -748,10 +766,34 @@ void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                 return;
         }
 
-        sdata->local->csa_channel = new_ch;
-
         ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
 
+        if (sdata->local->use_chanctx) {
+                sdata_info(sdata,
+                           "not handling channel switch with channel contexts\n");
+                ieee80211_queue_work(&sdata->local->hw,
+                                     &ifmgd->csa_connection_drop_work);
+        }
+
+        mutex_lock(&sdata->local->chanctx_mtx);
+        if (WARN_ON(!rcu_access_pointer(sdata->vif.chanctx_conf))) {
+                mutex_unlock(&sdata->local->chanctx_mtx);
+                return;
+        }
+        chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
+                               struct ieee80211_chanctx, conf);
+        if (chanctx->refcount > 1) {
+                sdata_info(sdata,
+                           "channel switch with multiple interfaces on the same channel, disconnecting\n");
+                ieee80211_queue_work(&sdata->local->hw,
+                                     &ifmgd->csa_connection_drop_work);
+                mutex_unlock(&sdata->local->chanctx_mtx);
+                return;
+        }
+        mutex_unlock(&sdata->local->chanctx_mtx);
+
+        sdata->local->csa_channel = new_ch;
+
         if (sw_elem->mode)
                 ieee80211_stop_queues_by_reason(&sdata->local->hw,
                                 IEEE80211_QUEUE_STOP_REASON_CSA);
@@ -1280,7 +1322,7 @@ static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
         }
 
         use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
-        if (sdata->local->oper_channel->band == IEEE80211_BAND_5GHZ)
+        if (ieee80211_get_sdata_band(sdata) == IEEE80211_BAND_5GHZ)
                 use_short_slot = true;
 
         if (use_protection != bss_conf->use_cts_prot) {
@@ -1465,9 +1507,7 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
         changed |= BSS_CHANGED_BSSID | BSS_CHANGED_HT;
         ieee80211_bss_info_change_notify(sdata, changed);
 
-        /* channel(_type) changes are handled by ieee80211_hw_config */
-        WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
-        ieee80211_hw_config(local, 0);
+        ieee80211_vif_release_channel(sdata);
 
         /* disassociated - set to defaults now */
         ieee80211_set_wmm_default(sdata, false);
@@ -1589,7 +1629,7 @@ static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
 
                 ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
                                          0, (u32) -1, true, false,
-                                         ifmgd->associated->channel);
+                                         ifmgd->associated->channel, false);
         }
 
         ifmgd->probe_timeout = jiffies + msecs_to_jiffies(probe_wait_ms);
@@ -1692,8 +1732,7 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
                 ssid_len = ssid[1];
 
         skb = ieee80211_build_probe_req(sdata, cbss->bssid,
-                                        (u32) -1,
-                                        sdata->local->oper_channel,
+                                        (u32) -1, cbss->channel,
                                         ssid + 2, ssid_len,
                                         NULL, 0, true);
 
@@ -1804,6 +1843,7 @@ static void ieee80211_destroy_auth_data(struct ieee80211_sub_if_data *sdata,
 
                 memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
+                ieee80211_vif_release_channel(sdata);
         }
 
         cfg80211_put_bss(auth_data->bss);
@@ -2030,6 +2070,7 @@ static void ieee80211_destroy_assoc_data(struct ieee80211_sub_if_data *sdata,
 
                 memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BSSID);
+                ieee80211_vif_release_channel(sdata);
         }
 
         kfree(assoc_data);
@@ -2091,7 +2132,7 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata,
                 return false;
         }
 
-        sband = local->hw.wiphy->bands[local->oper_channel->band];
+        sband = local->hw.wiphy->bands[ieee80211_get_sdata_band(sdata)];
 
         if (elems.ht_cap_elem && !(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
@@ -2369,6 +2410,8 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         size_t baselen;
         struct ieee802_11_elems elems;
         struct ieee80211_local *local = sdata->local;
+        struct ieee80211_chanctx_conf *chanctx_conf;
+        struct ieee80211_channel *chan;
         u32 changed = 0;
         bool erp_valid, directed_tim = false;
         u8 erp_value = 0;
@@ -2382,8 +2425,19 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         if (baselen > len)
                 return;
 
-        if (rx_status->freq != local->oper_channel->center_freq)
+        rcu_read_lock();
+        chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+        if (!chanctx_conf) {
+                rcu_read_unlock();
                 return;
+        }
+
+        if (rx_status->freq != chanctx_conf->channel->center_freq) {
+                rcu_read_unlock();
+                return;
+        }
+        chan = chanctx_conf->channel;
+        rcu_read_unlock();
 
         if (ifmgd->assoc_data && !ifmgd->assoc_data->have_beacon &&
             ether_addr_equal(mgmt->bssid, ifmgd->assoc_data->bss->bssid)) {
@@ -2546,7 +2600,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
             !(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {
                 struct ieee80211_supported_band *sband;
 
-                sband = local->hw.wiphy->bands[local->oper_channel->band];
+                sband = local->hw.wiphy->bands[chan->band];
 
                 changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
                                                   bssid, true);
@@ -2555,7 +2609,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         if (elems.country_elem && elems.pwr_constr_elem &&
             mgmt->u.probe_resp.capab_info &
                                 cpu_to_le16(WLAN_CAPABILITY_SPECTRUM_MGMT))
-                ieee80211_handle_pwr_constr(sdata, local->oper_channel,
+                ieee80211_handle_pwr_constr(sdata, chan,
                                             elems.country_elem,
                                             elems.country_elem_len,
                                             elems.pwr_constr_elem);
@@ -2728,7 +2782,7 @@ static int ieee80211_probe_auth(struct ieee80211_sub_if_data *sdata)
                  */
                 ieee80211_send_probe_req(sdata, NULL, ssidie + 2, ssidie[1],
                                          NULL, 0, (u32) -1, true, false,
-                                         auth_data->bss->channel);
+                                         auth_data->bss->channel, false);
         }
 
         auth_data->timeout = jiffies + IEEE80211_AUTH_TIMEOUT;
@@ -3118,20 +3172,9 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
-        if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
-                /* can only fail due to HT40+/- mismatch */
-                channel_type = NL80211_CHAN_HT20;
-                sdata_info(sdata,
-                           "disabling 40 MHz due to multi-vif mismatch\n");
-                ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
-                WARN_ON(!ieee80211_set_channel_type(local, sdata,
-                                                    channel_type));
-        }
-
-        local->oper_channel = cbss->channel;
-        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-
-        return 0;
+        ieee80211_vif_release_channel(sdata);
+        return ieee80211_vif_use_channel(sdata, cbss->channel, channel_type,
+                                         IEEE80211_CHANCTX_SHARED);
 }
 
 static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
@@ -3201,7 +3244,7 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
                 sdata->vif.bss_conf.basic_rates = basic_rates;
 
                 /* cf. IEEE 802.11 9.2.12 */
-                if (local->oper_channel->band == IEEE80211_BAND_2GHZ &&
+                if (cbss->channel->band == IEEE80211_BAND_2GHZ &&
                     have_higher_than_11mbit)
                         sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
                 else