From 21f83589644bb2ed98079bf1e2154c8e70ca6a6c Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Sat, 18 Dec 2010 17:20:47 +0100
Subject: mac80211: implement hardware offload for remain-on-channel

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>
---
 net/mac80211/cfg.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

(limited to 'net/mac80211/cfg.c')

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5892b030245..168a6ba8fc2 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -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;
 
-- 
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