5 files changed, 153 insertions, 5 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 9448a5b1bb15..389e86a54fc4 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -712,6 +712,28 @@ struct ieee80211_conf {
 };
 
 /**
+ * struct ieee80211_channel_switch - holds the channel switch data
+ *
+ * The information provided in this structure is required for channel switch
+ * operation.
+ *
+ * @timestamp: value in microseconds of the 64-bit Time Synchronization
+ *      Function (TSF) timer when the frame containing the channel switch
+ *      announcement was received. This is simply the rx.mactime parameter
+ *      the driver passed into mac80211.
+ * @block_tx: Indicates whether transmission must be blocked before the
+ *      scheduled channel switch, as indicated by the AP.
+ * @channel: the new channel to switch to
+ * @count: the number of TBTT's until the channel switch event
+ */
+struct ieee80211_channel_switch {
+        u64 timestamp;
+        bool block_tx;
+        struct ieee80211_channel *channel;
+        u8 count;
+};
+
+/**
  * struct ieee80211_vif - per-interface data
  *
  * Data in this structure is continually present for driver
@@ -1631,6 +1653,11 @@ enum ieee80211_ampdu_mlme_action {
  * @flush: Flush all pending frames from the hardware queue, making sure
  *      that the hardware queues are empty. If the parameter @drop is set
  *      to %true, pending frames may be dropped. The callback can sleep.
+ *
+ * @channel_switch: Drivers that need (or want) to offload the channel
+ *      switch operation for CSAs received from the AP may implement this
+ *      callback. They must then call ieee80211_chswitch_done() to indicate
+ *      completion of the channel switch.
  */
 struct ieee80211_ops {
         int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -1694,6 +1721,8 @@ struct ieee80211_ops {
         int (*testmode_cmd)(struct ieee80211_hw *hw, void *data, int len);
 #endif
         void (*flush)(struct ieee80211_hw *hw, bool drop);
+        void (*channel_switch)(struct ieee80211_hw *hw,
+                               struct ieee80211_channel_switch *ch_switch);
 };
 
 /**
@@ -2444,6 +2473,16 @@ void ieee80211_cqm_rssi_notify(struct ieee80211_vif *vif,
                                enum nl80211_cqm_rssi_threshold_event rssi_event,
                                gfp_t gfp);
 
+/**
+ * ieee80211_chswitch_done - Complete channel switch process
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @success: make the channel switch successful or not
+ *
+ * Complete the channel switch post-process: set the new operational channel
+ * and wake up the suspended queues.
+ */
+void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success);
+
 /* Rate control API */
 
 /**
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 997008e236ff..5662bb5190c3 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -373,4 +373,15 @@ static inline void drv_flush(struct ieee80211_local *local, bool drop)
         if (local->ops->flush)
                 local->ops->flush(&local->hw, drop);
 }
+
+static inline void drv_channel_switch(struct ieee80211_local *local,
+                                     struct ieee80211_channel_switch *ch_switch)
+{
+        might_sleep();
+
+        local->ops->channel_switch(&local->hw, ch_switch);
+
+        trace_drv_channel_switch(local, ch_switch);
+}
+
 #endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index ce734b58d07a..6a9b2342a9c2 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -774,6 +774,34 @@ TRACE_EVENT(drv_flush,
         )
 );
 
+TRACE_EVENT(drv_channel_switch,
+        TP_PROTO(struct ieee80211_local *local,
+                 struct ieee80211_channel_switch *ch_switch),
+
+        TP_ARGS(local, ch_switch),
+
+        TP_STRUCT__entry(
+                LOCAL_ENTRY
+                __field(u64, timestamp)
+                __field(bool, block_tx)
+                __field(u16, freq)
+                __field(u8, count)
+        ),
+
+        TP_fast_assign(
+                LOCAL_ASSIGN;
+                __entry->timestamp = ch_switch->timestamp;
+                __entry->block_tx = ch_switch->block_tx;
+                __entry->freq = ch_switch->channel->center_freq;
+                __entry->count = ch_switch->count;
+        ),
+
+        TP_printk(
+                LOCAL_PR_FMT " new freq:%u count:%d",
+                LOCAL_PR_ARG, __entry->freq, __entry->count
+        )
+);
+
 /*
  * Tracing for API calls that drivers call.
  */
@@ -992,6 +1020,27 @@ TRACE_EVENT(api_sta_block_awake,
         )
 );
 
+TRACE_EVENT(api_chswitch_done,
+        TP_PROTO(struct ieee80211_sub_if_data *sdata, bool success),
+
+        TP_ARGS(sdata, success),
+
+        TP_STRUCT__entry(
+                VIF_ENTRY
+                __field(bool, success)
+        ),
+
+        TP_fast_assign(
+                VIF_ASSIGN;
+                __entry->success = success;
+        ),
+
+        TP_printk(
+                VIF_PR_FMT " success=%d",
+                VIF_PR_ARG, __entry->success
+        )
+);
+
 /*
  * Tracing for internal functions
  * (which may also be called in response to driver calls)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 69e7f4131f46..1c8e24706685 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -999,7 +999,8 @@ int ieee80211_max_network_latency(struct notifier_block *nb,
                                   unsigned long data, void *dummy);
 void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                       struct ieee80211_channel_sw_ie *sw_elem,
-                                      struct ieee80211_bss *bss);
+                                      struct ieee80211_bss *bss,
+                                      u64 timestamp);
 void ieee80211_sta_quiesce(struct ieee80211_sub_if_data *sdata);
 void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata);
 
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7bfb0ebaaf00..6b74489fb9c6 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -341,7 +341,11 @@ static void ieee80211_chswitch_work(struct work_struct *work)
                 goto out;
 
         sdata->local->oper_channel = sdata->local->csa_channel;
-        ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_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);
+        }
 
         /* XXX: shouldn't really modify cfg80211-owned data! */
         ifmgd->associated->channel = sdata->local->oper_channel;
@@ -353,6 +357,29 @@ static void ieee80211_chswitch_work(struct work_struct *work)
         mutex_unlock(&ifmgd->mtx);
 }
 
+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;
+
+        trace_api_chswitch_done(sdata, success);
+        if (!success) {
+                /*
+                 * If the channel switch was not successful, stay
+                 * around on the old channel. We currently lack
+                 * good handling of this situation, possibly we
+                 * should just drop the association.
+                 */
+                sdata->local->csa_channel = sdata->local->oper_channel;
+        }
+
+        ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
+}
+EXPORT_SYMBOL(ieee80211_chswitch_done);
+
 static void ieee80211_chswitch_timer(unsigned long data)
 {
         struct ieee80211_sub_if_data *sdata =
@@ -369,7 +396,8 @@ static void ieee80211_chswitch_timer(unsigned long data)
 
 void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                                       struct ieee80211_channel_sw_ie *sw_elem,
-                                      struct ieee80211_bss *bss)
+                                      struct ieee80211_bss *bss,
+                                      u64 timestamp)
 {
         struct cfg80211_bss *cbss =
                 container_of((void *)bss, struct cfg80211_bss, priv);
@@ -397,6 +425,24 @@ void ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
         sdata->local->csa_channel = new_ch;
 
+        if (sdata->local->ops->channel_switch) {
+                /* use driver's channel switch callback */
+                struct ieee80211_channel_switch ch_switch;
+                memset(&ch_switch, 0, sizeof(ch_switch));
+                ch_switch.timestamp = timestamp;
+                if (sw_elem->mode) {
+                        ch_switch.block_tx = true;
+                        ieee80211_stop_queues_by_reason(&sdata->local->hw,
+                                        IEEE80211_QUEUE_STOP_REASON_CSA);
+                }
+                ch_switch.channel = new_ch;
+                ch_switch.count = sw_elem->count;
+                ifmgd->flags |= IEEE80211_STA_CSA_RECEIVED;
+                drv_channel_switch(sdata->local, &ch_switch);
+                return;
+        }
+
+        /* channel switch handled in software */
         if (sw_elem->count <= 1) {
                 ieee80211_queue_work(&sdata->local->hw, &ifmgd->chswitch_work);
         } else {
@@ -1316,7 +1362,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                                                         ETH_ALEN) == 0)) {
                 struct ieee80211_channel_sw_ie *sw_elem =
                         (struct ieee80211_channel_sw_ie *)elems->ch_switch_elem;
-                ieee80211_sta_process_chanswitch(sdata, sw_elem, bss);
+                ieee80211_sta_process_chanswitch(sdata, sw_elem,
+                                                 bss, rx_status->mactime);
         }
 }
 
@@ -1648,7 +1695,8 @@ static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 
                         ieee80211_sta_process_chanswitch(sdata,
                                         &mgmt->u.action.u.chan_switch.sw_elem,
-                                        (void *)ifmgd->associated->priv);
+                                        (void *)ifmgd->associated->priv,
+                                        rx_status->mactime);
                         break;
                 }
                 mutex_unlock(&ifmgd->mtx);