mac80211: implement hardware offload for remain-on-channel
Johannes Berg [Sat, 18 Dec 2010 16:20:47 +0000 (17:20 +0100)]
This allows drivers to support remain-on-channel
offload if they implement smarter timing or need
to use a device implementation like iwlwifi.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h
net/mac80211/cfg.c
net/mac80211/driver-ops.h
net/mac80211/driver-trace.h
net/mac80211/ieee80211_i.h
net/mac80211/iface.c
net/mac80211/main.c
net/mac80211/offchannel.c

index 479c35e..5b3fd5a 100644 (file)
@@ -365,6 +365,7 @@ enum mac80211_tx_control_flags {
        IEEE80211_TX_INTFL_NL80211_FRAME_TX     = BIT(21),
        IEEE80211_TX_CTL_LDPC                   = BIT(22),
        IEEE80211_TX_CTL_STBC                   = BIT(23) | BIT(24),
+       IEEE80211_TX_CTL_TX_OFFCHAN             = BIT(25),
 };
 
 #define IEEE80211_TX_CTL_STBC_SHIFT            23
@@ -1824,6 +1825,12 @@ struct ieee80211_ops {
        int (*napi_poll)(struct ieee80211_hw *hw, int budget);
        int (*set_antenna)(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant);
        int (*get_antenna)(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant);
+
+       int (*remain_on_channel)(struct ieee80211_hw *hw,
+                                struct ieee80211_channel *chan,
+                                enum nl80211_channel_type channel_type,
+                                int duration);
+       int (*cancel_remain_on_channel)(struct ieee80211_hw *hw);
 };
 
 /**
@@ -2729,6 +2736,18 @@ void ieee80211_request_smps(struct ieee80211_vif *vif,
  */
 void ieee80211_key_removed(struct ieee80211_key_conf *key_conf);
 
+/**
+ * ieee80211_ready_on_channel - notification of remain-on-channel start
+ * @hw: pointer as obtained from ieee80211_alloc_hw()
+ */
+void ieee80211_ready_on_channel(struct ieee80211_hw *hw);
+
+/**
+ * ieee80211_remain_on_channel_expired - remain_on_channel duration expired
+ * @hw: pointer as obtained from ieee80211_alloc_hw()
+ */
+void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw);
+
 /* Rate control API */
 
 /**
index 5892b03..168a6ba 100644 (file)
@@ -1593,6 +1593,37 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
        return 0;
 }
 
+static int ieee80211_remain_on_channel_hw(struct ieee80211_local *local,
+                                         struct net_device *dev,
+                                         struct ieee80211_channel *chan,
+                                         enum nl80211_channel_type chantype,
+                                         unsigned int duration, u64 *cookie)
+{
+       int ret;
+       u32 random_cookie;
+
+       lockdep_assert_held(&local->mtx);
+
+       if (local->hw_roc_cookie)
+               return -EBUSY;
+       /* must be nonzero */
+       random_cookie = random32() | 1;
+
+       *cookie = random_cookie;
+       local->hw_roc_dev = dev;
+       local->hw_roc_cookie = random_cookie;
+       local->hw_roc_channel = chan;
+       local->hw_roc_channel_type = chantype;
+       local->hw_roc_duration = duration;
+       ret = drv_remain_on_channel(local, chan, chantype, duration);
+       if (ret) {
+               local->hw_roc_channel = NULL;
+               local->hw_roc_cookie = 0;
+       }
+
+       return ret;
+}
+
 static int ieee80211_remain_on_channel(struct wiphy *wiphy,
                                       struct net_device *dev,
                                       struct ieee80211_channel *chan,
@@ -1601,16 +1632,62 @@ static int ieee80211_remain_on_channel(struct wiphy *wiphy,
                                       u64 *cookie)
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       struct ieee80211_local *local = sdata->local;
+
+       if (local->ops->remain_on_channel) {
+               int ret;
+
+               mutex_lock(&local->mtx);
+               ret = ieee80211_remain_on_channel_hw(local, dev,
+                                                    chan, channel_type,
+                                                    duration, cookie);
+               mutex_unlock(&local->mtx);
+
+               return ret;
+       }
 
        return ieee80211_wk_remain_on_channel(sdata, chan, channel_type,
                                              duration, cookie);
 }
 
+static int ieee80211_cancel_remain_on_channel_hw(struct ieee80211_local *local,
+                                                u64 cookie)
+{
+       int ret;
+
+       lockdep_assert_held(&local->mtx);
+
+       if (local->hw_roc_cookie != cookie)
+               return -ENOENT;
+
+       ret = drv_cancel_remain_on_channel(local);
+       if (ret)
+               return ret;
+
+       local->hw_roc_cookie = 0;
+       local->hw_roc_channel = NULL;
+
+       ieee80211_recalc_idle(local);
+
+       return 0;
+}
+
 static int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
                                              struct net_device *dev,
                                              u64 cookie)
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+       struct ieee80211_local *local = sdata->local;
+
+       if (local->ops->cancel_remain_on_channel) {
+               int ret;
+
+               mutex_lock(&local->mtx);
+               ret = ieee80211_cancel_remain_on_channel_hw(local, cookie);
+               mutex_unlock(&local->mtx);
+
+               return ret;
+       }
 
        return ieee80211_wk_cancel_remain_on_channel(sdata, cookie);
 }
@@ -1662,6 +1739,12 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct net_device *dev,
             channel_type != local->_oper_channel_type))
                is_offchan = true;
 
+       if (chan == local->hw_roc_channel) {
+               /* TODO: check channel type? */
+               is_offchan = false;
+               flags |= IEEE80211_TX_CTL_TX_OFFCHAN;
+       }
+
        if (is_offchan && !offchan)
                return -EBUSY;
 
index af0c439..98d5899 100644 (file)
@@ -465,4 +465,34 @@ static inline int drv_get_antenna(struct ieee80211_local *local,
        return ret;
 }
 
+static inline int drv_remain_on_channel(struct ieee80211_local *local,
+                                       struct ieee80211_channel *chan,
+                                       enum nl80211_channel_type chantype,
+                                       unsigned int duration)
+{
+       int ret;
+
+       might_sleep();
+
+       trace_drv_remain_on_channel(local, chan, chantype, duration);
+       ret = local->ops->remain_on_channel(&local->hw, chan, chantype,
+                                           duration);
+       trace_drv_return_int(local, ret);
+
+       return ret;
+}
+
+static inline int drv_cancel_remain_on_channel(struct ieee80211_local *local)
+{
+       int ret;
+
+       might_sleep();
+
+       trace_drv_cancel_remain_on_channel(local);
+       ret = local->ops->cancel_remain_on_channel(&local->hw);
+       trace_drv_return_int(local, ret);
+
+       return ret;
+}
+
 #endif /* __MAC80211_DRIVER_OPS */
index c2772f2..49c8421 100644 (file)
@@ -933,6 +933,50 @@ TRACE_EVENT(drv_get_antenna,
        )
 );
 
+TRACE_EVENT(drv_remain_on_channel,
+       TP_PROTO(struct ieee80211_local *local, struct ieee80211_channel *chan,
+                enum nl80211_channel_type chantype, unsigned int duration),
+
+       TP_ARGS(local, chan, chantype, duration),
+
+       TP_STRUCT__entry(
+               LOCAL_ENTRY
+               __field(int, center_freq)
+               __field(int, channel_type)
+               __field(unsigned int, duration)
+       ),
+
+       TP_fast_assign(
+               LOCAL_ASSIGN;
+               __entry->center_freq = chan->center_freq;
+               __entry->channel_type = chantype;
+               __entry->duration = duration;
+       ),
+
+       TP_printk(
+               LOCAL_PR_FMT " freq:%dMHz duration:%dms",
+               LOCAL_PR_ARG, __entry->center_freq, __entry->duration
+       )
+);
+
+TRACE_EVENT(drv_cancel_remain_on_channel,
+       TP_PROTO(struct ieee80211_local *local),
+
+       TP_ARGS(local),
+
+       TP_STRUCT__entry(
+               LOCAL_ENTRY
+       ),
+
+       TP_fast_assign(
+               LOCAL_ASSIGN;
+       ),
+
+       TP_printk(
+               LOCAL_PR_FMT, LOCAL_PR_ARG
+       )
+);
+
 /*
  * Tracing for API calls that drivers call.
  */
@@ -1170,6 +1214,42 @@ TRACE_EVENT(api_chswitch_done,
        )
 );
 
+TRACE_EVENT(api_ready_on_channel,
+       TP_PROTO(struct ieee80211_local *local),
+
+       TP_ARGS(local),
+
+       TP_STRUCT__entry(
+               LOCAL_ENTRY
+       ),
+
+       TP_fast_assign(
+               LOCAL_ASSIGN;
+       ),
+
+       TP_printk(
+               LOCAL_PR_FMT, LOCAL_PR_ARG
+       )
+);
+
+TRACE_EVENT(api_remain_on_channel_expired,
+       TP_PROTO(struct ieee80211_local *local),
+
+       TP_ARGS(local),
+
+       TP_STRUCT__entry(
+               LOCAL_ENTRY
+       ),
+
+       TP_fast_assign(
+               LOCAL_ASSIGN;
+       ),
+
+       TP_printk(
+               LOCAL_PR_FMT, LOCAL_PR_ARG
+       )
+);
+
 /*
  * Tracing for internal functions
  * (which may also be called in response to driver calls)
index 95cdd2a..f866af8 100644 (file)
@@ -951,6 +951,13 @@ struct ieee80211_local {
        } debugfs;
 #endif
 
+       struct ieee80211_channel *hw_roc_channel;
+       struct net_device *hw_roc_dev;
+       struct work_struct hw_roc_start, hw_roc_done;
+       enum nl80211_channel_type hw_roc_channel_type;
+       unsigned int hw_roc_duration;
+       u32 hw_roc_cookie;
+
        /* dummy netdev for use w/ NAPI */
        struct net_device napi_dev;
 
@@ -1142,6 +1149,7 @@ void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
 void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
 void ieee80211_offchannel_return(struct ieee80211_local *local,
                                 bool enable_beaconing);
+void ieee80211_hw_roc_setup(struct ieee80211_local *local);
 
 /* interface handling */
 int ieee80211_iface_init(void);
index b6db237..8acba45 100644 (file)
@@ -1264,7 +1264,7 @@ u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
 {
        struct ieee80211_sub_if_data *sdata;
        int count = 0;
-       bool working = false, scanning = false;
+       bool working = false, scanning = false, hw_roc = false;
        struct ieee80211_work *wk;
        unsigned int led_trig_start = 0, led_trig_stop = 0;
 
@@ -1308,6 +1308,9 @@ u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
                local->scan_sdata->vif.bss_conf.idle = false;
        }
 
+       if (local->hw_roc_channel)
+               hw_roc = true;
+
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (sdata->old_idle == sdata->vif.bss_conf.idle)
                        continue;
@@ -1316,7 +1319,7 @@ u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
                ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
        }
 
-       if (working || scanning)
+       if (working || scanning || hw_roc)
                led_trig_start |= IEEE80211_TPT_LEDTRIG_FL_WORK;
        else
                led_trig_stop |= IEEE80211_TPT_LEDTRIG_FL_WORK;
@@ -1328,6 +1331,8 @@ u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
 
        ieee80211_mod_tpt_led_trig(local, led_trig_start, led_trig_stop);
 
+       if (hw_roc)
+               return ieee80211_idle_off(local, "hw remain-on-channel");
        if (working)
                return ieee80211_idle_off(local, "working");
        if (scanning)
index 4b088b3..485d36b 100644 (file)
@@ -609,6 +609,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 
        ieee80211_led_names(local);
 
+       ieee80211_hw_roc_setup(local);
+
        return local_to_hw(local);
 }
 EXPORT_SYMBOL(ieee80211_alloc_hw);
@@ -753,7 +755,8 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
                }
        }
 
-       local->hw.wiphy->max_remain_on_channel_duration = 5000;
+       if (!local->ops->remain_on_channel)
+               local->hw.wiphy->max_remain_on_channel_duration = 5000;
 
        result = wiphy_register(local->hw.wiphy);
        if (result < 0)
index 4b56409..49b9ec2 100644 (file)
@@ -14,6 +14,7 @@
  */
 #include <net/mac80211.h>
 #include "ieee80211_i.h"
+#include "driver-trace.h"
 
 /*
  * inform AP that we will go to sleep so that it will buffer the frames
@@ -190,3 +191,77 @@ void ieee80211_offchannel_return(struct ieee80211_local *local,
        }
        mutex_unlock(&local->iflist_mtx);
 }
+
+static void ieee80211_hw_roc_start(struct work_struct *work)
+{
+       struct ieee80211_local *local =
+               container_of(work, struct ieee80211_local, hw_roc_start);
+
+       mutex_lock(&local->mtx);
+
+       if (!local->hw_roc_channel) {
+               mutex_unlock(&local->mtx);
+               return;
+       }
+
+       ieee80211_recalc_idle(local);
+
+       cfg80211_ready_on_channel(local->hw_roc_dev, local->hw_roc_cookie,
+                                 local->hw_roc_channel,
+                                 local->hw_roc_channel_type,
+                                 local->hw_roc_duration,
+                                 GFP_KERNEL);
+       mutex_unlock(&local->mtx);
+}
+
+void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
+{
+       struct ieee80211_local *local = hw_to_local(hw);
+
+       trace_api_ready_on_channel(local);
+
+       ieee80211_queue_work(hw, &local->hw_roc_start);
+}
+EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
+
+static void ieee80211_hw_roc_done(struct work_struct *work)
+{
+       struct ieee80211_local *local =
+               container_of(work, struct ieee80211_local, hw_roc_done);
+
+       mutex_lock(&local->mtx);
+
+       if (!local->hw_roc_channel) {
+               mutex_unlock(&local->mtx);
+               return;
+       }
+
+       cfg80211_remain_on_channel_expired(local->hw_roc_dev,
+                                          local->hw_roc_cookie,
+                                          local->hw_roc_channel,
+                                          local->hw_roc_channel_type,
+                                          GFP_KERNEL);
+
+       local->hw_roc_channel = NULL;
+       local->hw_roc_cookie = 0;
+
+       ieee80211_recalc_idle(local);
+
+       mutex_unlock(&local->mtx);
+}
+
+void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
+{
+       struct ieee80211_local *local = hw_to_local(hw);
+
+       trace_api_remain_on_channel_expired(local);
+
+       ieee80211_queue_work(hw, &local->hw_roc_done);
+}
+EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
+
+void ieee80211_hw_roc_setup(struct ieee80211_local *local)
+{
+       INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
+       INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
+}