From 0c2bef4621c5feb5bda9068c9964b2e9acf57017 Mon Sep 17 00:00:00 2001
From: Monam Agarwal <monamagarwal123@gmail.com>
Date: Mon, 24 Mar 2014 00:51:43 +0530
Subject: mac80211: use RCU_INIT_POINTER

rcu_assign_pointer() ensures that the initialization of a structure is
carried out before storing a pointer to that structure. However, in the
case that NULL is assigned there's no structure to initialize so using
RCU_INIT_POINTER instead is safe and more efficient.

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
[squash eight tiny patches, rewrite commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index bd1fd8ea5105..b297bd3043a8 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -392,7 +392,7 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 	lockdep_assert_held(&local->chanctx_mtx);
 
 	ctx->refcount--;
-	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
+	RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
 
 	sdata->vif.bss_conf.idle = true;
 
-- 
cgit v1.2.3


From 73de86a38962b18edad3205c2358599dd9c83e9f Mon Sep 17 00:00:00 2001
From: Luciano Coelho <luciano.coelho@intel.com>
Date: Thu, 13 Feb 2014 11:31:59 +0200
Subject: cfg80211/mac80211: move interface counting for combination check to
 mac80211

Move the counting part of the interface combination check from
cfg80211 to mac80211.

This is needed to simplify locking when the driver has to perform a
combination check by itself (eg. with channel-switch).

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/cfg80211.h     |  2 --
 net/mac80211/cfg.c         |  2 --
 net/mac80211/chan.c        | 17 +++++++++++
 net/mac80211/ieee80211_i.h |  4 +++
 net/mac80211/util.c        | 72 ++++++++++++++++++++++++++++++++++++++++++++++
 net/wireless/core.h        | 13 ++-------
 net/wireless/ibss.c        |  4 +++
 net/wireless/mesh.c        | 28 ------------------
 net/wireless/mlme.c        | 14 +--------
 net/wireless/nl80211.c     | 29 +++----------------
 net/wireless/util.c        |  5 ++++
 11 files changed, 110 insertions(+), 80 deletions(-)

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

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 92a65c331cf4..fb8afcee62b4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -662,7 +662,6 @@ struct cfg80211_acl_data {
  * @p2p_opp_ps: P2P opportunistic PS
  * @acl: ACL configuration used by the drivers which has support for
  *	MAC address based access control
- * @radar_required: set if radar detection is required
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_chan_def chandef;
@@ -680,7 +679,6 @@ struct cfg80211_ap_settings {
 	u8 p2p_ctwindow;
 	bool p2p_opp_ps;
 	const struct cfg80211_acl_data *acl;
-	bool radar_required;
 };
 
 /**
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 906bc3b05aae..8bf94eaa0456 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -972,7 +972,6 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	sdata->needed_rx_chains = sdata->local->rx_chains;
 
 	mutex_lock(&local->mtx);
-	sdata->radar_required = params->radar_required;
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
 	mutex_unlock(&local->mtx);
@@ -2930,7 +2929,6 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	/* whatever, but channel contexts should not complain about that one */
 	sdata->smps_mode = IEEE80211_SMPS_OFF;
 	sdata->needed_rx_chains = local->rx_chains;
-	sdata->radar_required = true;
 
 	err = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_SHARED);
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index b297bd3043a8..623b336f3efd 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -519,6 +519,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_chanctx *ctx;
+	u8 radar_detect_width = 0;
 	int ret;
 
 	lockdep_assert_held(&local->mtx);
@@ -526,6 +527,22 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 
 	mutex_lock(&local->chanctx_mtx);
+
+	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
+					    chandef,
+					    sdata->wdev.iftype);
+	if (ret < 0)
+		goto out;
+	if (ret > 0)
+		radar_detect_width = BIT(chandef->width);
+
+	sdata->radar_required = ret;
+
+	ret = ieee80211_check_combinations(sdata, chandef, mode,
+					   radar_detect_width);
+	if (ret < 0)
+		goto out;
+
 	__ieee80211_vif_release_channel(sdata);
 
 	ctx = ieee80211_find_chanctx(local, chandef, mode);
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 222c28b75315..09213fd87f8d 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1805,6 +1805,10 @@ int ieee80211_cs_headroom(struct ieee80211_local *local,
 			  enum nl80211_iftype iftype);
 void ieee80211_recalc_dtim(struct ieee80211_local *local,
 			   struct ieee80211_sub_if_data *sdata);
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 73af7398850b..436f98870066 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2797,3 +2797,75 @@ void ieee80211_recalc_dtim(struct ieee80211_local *local,
 
 	ps->dtim_count = dtim_count;
 }
+
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *sdata_iter;
+	enum nl80211_iftype iftype = sdata->wdev.iftype;
+	int num[NUM_NL80211_IFTYPES];
+	struct ieee80211_chanctx *ctx;
+	int num_different_channels = 1;
+	int total = 1;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	if (WARN_ON(hweight32(radar_detect) > 1))
+		return -EINVAL;
+
+	if (WARN_ON(chanmode == IEEE80211_CHANCTX_SHARED && !chandef->chan))
+		return -EINVAL;
+
+	if (WARN_ON(iftype >= NUM_NL80211_IFTYPES))
+		return -EINVAL;
+
+	/* Always allow software iftypes */
+	if (local->hw.wiphy->software_iftypes & BIT(iftype)) {
+		if (radar_detect)
+			return -EINVAL;
+		return 0;
+	}
+
+	memset(num, 0, sizeof(num));
+
+	if (iftype != NL80211_IFTYPE_UNSPECIFIED)
+		num[iftype] = 1;
+
+	list_for_each_entry(ctx, &local->chanctx_list, list) {
+		if (ctx->conf.radar_enabled)
+			radar_detect |= BIT(ctx->conf.def.width);
+		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) {
+			num_different_channels++;
+			continue;
+		}
+		if ((chanmode == IEEE80211_CHANCTX_SHARED) &&
+		    cfg80211_chandef_compatible(chandef,
+						&ctx->conf.def))
+			continue;
+		num_different_channels++;
+	}
+
+	list_for_each_entry_rcu(sdata_iter, &local->interfaces, list) {
+		struct wireless_dev *wdev_iter;
+
+		wdev_iter = &sdata_iter->wdev;
+
+		if (sdata_iter == sdata ||
+		    rcu_access_pointer(sdata_iter->vif.chanctx_conf) == NULL ||
+		    local->hw.wiphy->software_iftypes & BIT(wdev_iter->iftype))
+			continue;
+
+		num[wdev_iter->iftype]++;
+		total++;
+	}
+
+	if (total == 1 && !radar_detect)
+		return 0;
+
+	return cfg80211_check_combinations(local->hw.wiphy,
+					   num_different_channels,
+					   radar_detect, num);
+}
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 6f6f75609852..6684c5d965d8 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -417,6 +417,9 @@ cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
 			      struct wireless_dev *wdev,
 			      enum nl80211_iftype iftype)
 {
+	/* TODO: For this function, we'll probably need to keep some
+	 * kind of interface combination check in cfg80211...
+	 */
 	return cfg80211_can_use_iftype_chan(rdev, wdev, iftype, NULL,
 					    CHAN_MODE_UNDEFINED, 0);
 }
@@ -431,16 +434,6 @@ cfg80211_can_add_interface(struct cfg80211_registered_device *rdev,
 	return cfg80211_can_change_interface(rdev, NULL, iftype);
 }
 
-static inline int
-cfg80211_can_use_chan(struct cfg80211_registered_device *rdev,
-		      struct wireless_dev *wdev,
-		      struct ieee80211_channel *chan,
-		      enum cfg80211_chan_mode chanmode)
-{
-	return cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					    chan, chanmode, 0);
-}
-
 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 {
 	unsigned long end = jiffies;
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index a6b5bdad039c..faf4961d47d8 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -135,6 +135,10 @@ static int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 		radar_detect_width = BIT(params->chandef.width);
 	}
 
+	/* TODO: We need to check the combinations at this point, we
+	 * probably must move this call down to join_ibss() in
+	 * mac80211.
+	 */
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
 					   check_chan,
 					   (params->channel_fixed &&
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 6ebe883653a4..3ddfb7cd335e 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -99,7 +99,6 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 			 const struct mesh_config *conf)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
-	u8 radar_detect_width = 0;
 	int err;
 
 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
@@ -179,22 +178,6 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 				     NL80211_IFTYPE_MESH_POINT))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy,
-					    &setup->chandef,
-					    NL80211_IFTYPE_MESH_POINT);
-	if (err < 0)
-		return err;
-
-	if (err > 0)
-		radar_detect_width = BIT(setup->chandef.width);
-
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   setup->chandef.chan,
-					   CHAN_MODE_SHARED,
-					   radar_detect_width);
-	if (err)
-		return err;
-
 	err = rdev_join_mesh(rdev, dev, conf, setup);
 	if (!err) {
 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
@@ -240,17 +223,6 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 		if (!netif_running(wdev->netdev))
 			return -ENETDOWN;
 
-		/* cfg80211_can_use_chan() calls
-		 * cfg80211_can_use_iftype_chan() with no radar
-		 * detection, so if we're trying to use a radar
-		 * channel here, something is wrong.
-		 */
-		WARN_ON_ONCE(chandef->chan->flags & IEEE80211_CHAN_RADAR);
-		err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
-					    CHAN_MODE_SHARED);
-		if (err)
-			return err;
-
 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 						     chandef->chan);
 		if (!err)
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index c52ff59a3e96..4b4ba707fab9 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -233,14 +233,8 @@ int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 	if (!req.bss)
 		return -ENOENT;
 
-	err = cfg80211_can_use_chan(rdev, wdev, req.bss->channel,
-				    CHAN_MODE_SHARED);
-	if (err)
-		goto out;
-
 	err = rdev_auth(rdev, dev, &req);
 
-out:
 	cfg80211_put_bss(&rdev->wiphy, req.bss);
 	return err;
 }
@@ -306,16 +300,10 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 	if (!req->bss)
 		return -ENOENT;
 
-	err = cfg80211_can_use_chan(rdev, wdev, chan, CHAN_MODE_SHARED);
-	if (err)
-		goto out;
-
 	err = rdev_assoc(rdev, dev, req);
 	if (!err)
 		cfg80211_hold_bss(bss_from_pub(req->bss));
-
-out:
-	if (err)
+	else
 		cfg80211_put_bss(&rdev->wiphy, req->bss);
 
 	return err;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4f82b9b71db1..2b99aad33ae0 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3155,7 +3155,6 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_ap_settings params;
 	int err;
-	u8 radar_detect_width = 0;
 
 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
@@ -3275,24 +3274,6 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 				     wdev->iftype))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy,
-					    &params.chandef,
-					    NL80211_IFTYPE_AP);
-	if (err < 0)
-		return err;
-
-	if (err > 0) {
-		params.radar_required = true;
-		radar_detect_width = BIT(params.chandef.width);
-	}
-
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   params.chandef.chan,
-					   CHAN_MODE_SHARED,
-					   radar_detect_width);
-	if (err)
-		return err;
-
 	if (info->attrs[NL80211_ATTR_ACL_POLICY]) {
 		params.acl = parse_acl_data(&rdev->wiphy, info);
 		if (IS_ERR(params.acl))
@@ -5823,12 +5804,6 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 	if (!rdev->ops->start_radar_detection)
 		return -EOPNOTSUPP;
 
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   chandef.chan, CHAN_MODE_SHARED,
-					   BIT(chandef.width));
-	if (err)
-		return err;
-
 	cac_time_ms = cfg80211_chandef_dfs_cac_time(&rdev->wiphy, &chandef);
 	if (WARN_ON(!cac_time_ms))
 		cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
@@ -5957,6 +5932,10 @@ skip_beacons:
 		params.radar_required = true;
 	}
 
+	/* TODO: I left this here for now.  With channel switch, the
+	 * verification is a bit more complicated, because we only do
+	 * it later when the channel switch really happens.
+	 */
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
 					   params.chandef.chan,
 					   CHAN_MODE_SHARED,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 46f404df35e3..9bfc4c621509 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1375,6 +1375,11 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 
 	num[iftype] = 1;
 
+	/* TODO: We'll probably not need this anymore, since this
+	 * should only be called with CHAN_MODE_UNDEFINED. There are
+	 * still a couple of pending calls where other chanmodes are
+	 * used, but we should get rid of them.
+	 */
 	switch (chanmode) {
 	case CHAN_MODE_UNDEFINED:
 		break;
-- 
cgit v1.2.3


From 4e141dad266908735967b0961c8d90187825e0bc Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 5 Mar 2014 13:14:08 +0100
Subject: mac80211: protect AP VLAN list with local->mtx

It was impossible to change chanctx of master AP
for AP VLANs because the copy function requires
RTNL which can't be simply taken in mac80211 code
due to possible deadlocks.

This is required for future chanctx reservation
that re-bind vifs to new chanctx. This requires
safe AP VLAN iteration without RTNL.

Now VLANs can be iterated while holding either
RTNL or local->mtx because the list is modified
while holding both of these locks.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/cfg.c         | 5 +++--
 net/mac80211/chan.c        | 2 +-
 net/mac80211/ieee80211_i.h | 4 ++--
 net/mac80211/iface.c       | 9 ++++++++-
 4 files changed, 14 insertions(+), 6 deletions(-)

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

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 23d60110aebd..aa39381ca46d 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -983,10 +983,11 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	mutex_lock(&local->mtx);
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
+	if (!err)
+		ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
 	mutex_unlock(&local->mtx);
 	if (err)
 		return err;
-	ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
 
 	/*
 	 * Apply control port protocol, this allows us to
@@ -1139,8 +1140,8 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
 	local->total_ps_buffered -= skb_queue_len(&sdata->u.ap.ps.bc_buf);
 	skb_queue_purge(&sdata->u.ap.ps.bc_buf);
 
-	ieee80211_vif_copy_chanctx_to_vlans(sdata, true);
 	mutex_lock(&local->mtx);
+	ieee80211_vif_copy_chanctx_to_vlans(sdata, true);
 	ieee80211_vif_release_channel(sdata);
 	mutex_unlock(&local->mtx);
 
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 623b336f3efd..db0a344968eb 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -712,7 +712,7 @@ void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 	struct ieee80211_sub_if_data *vlan;
 	struct ieee80211_chanctx_conf *conf;
 
-	ASSERT_RTNL();
+	lockdep_assert_held(&local->mtx);
 
 	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
 		return;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 09213fd87f8d..c422f81d93ae 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -260,7 +260,7 @@ struct ieee80211_if_ap {
 
 	/* to be used after channel switch. */
 	struct cfg80211_beacon_data *next_beacon;
-	struct list_head vlans;
+	struct list_head vlans; /* write-protected with RTNL and local->mtx */
 
 	struct ps_data ps;
 	atomic_t num_mcast_sta; /* number of stations receiving multicast */
@@ -276,7 +276,7 @@ struct ieee80211_if_wds {
 };
 
 struct ieee80211_if_vlan {
-	struct list_head list;
+	struct list_head list; /* write-protected with RTNL and local->mtx */
 
 	/* used for all tx if the VLAN is configured to 4-addr mode */
 	struct sta_info __rcu *sta;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index ad5badd783d8..90b60633a27a 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -496,7 +496,9 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 		if (!sdata->bss)
 			return -ENOLINK;
 
+		mutex_lock(&local->mtx);
 		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
+		mutex_unlock(&local->mtx);
 
 		master = container_of(sdata->bss,
 				      struct ieee80211_sub_if_data, u.ap);
@@ -726,8 +728,11 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up)
 		drv_stop(local);
  err_del_bss:
 	sdata->bss = NULL;
-	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+		mutex_lock(&local->mtx);
 		list_del(&sdata->u.vlan.list);
+		mutex_unlock(&local->mtx);
+	}
 	/* might already be clear but that doesn't matter */
 	clear_bit(SDATA_STATE_RUNNING, &sdata->state);
 	return res;
@@ -879,7 +884,9 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_AP_VLAN:
+		mutex_lock(&local->mtx);
 		list_del(&sdata->u.vlan.list);
+		mutex_unlock(&local->mtx);
 		RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
 		/* no need to tell driver */
 		break;
-- 
cgit v1.2.3


From 33ffd952c252b7943dd5d051af3eeacc0bb3c23e Mon Sep 17 00:00:00 2001
From: Luciano Coelho <luciano.coelho@intel.com>
Date: Thu, 30 Jan 2014 22:08:16 +0200
Subject: mac80211: split ieee80211_vif_change_channel in two

ieee80211_vif_change_channel() locks chanctx_mtx.  When implementing
channel reservation for CS, we will need to call the function to
change channel when the lock is already held, so split the part that
requires the lock out and leave the locking in the original function.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 58 ++++++++++++++++++++++++++++++-----------------------
 1 file changed, 33 insertions(+), 25 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index db0a344968eb..503ee3083409 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -570,39 +570,20 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	return ret;
 }
 
-int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
-				 u32 *changed)
+static int __ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
+					  struct ieee80211_chanctx *ctx,
+					  u32 *changed)
 {
 	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_chanctx_conf *conf;
-	struct ieee80211_chanctx *ctx;
 	const struct cfg80211_chan_def *chandef = &sdata->csa_chandef;
-	int ret;
 	u32 chanctx_changed = 0;
 
-	lockdep_assert_held(&local->mtx);
-
-	/* should never be called if not performing a channel switch. */
-	if (WARN_ON(!sdata->vif.csa_active))
-		return -EINVAL;
-
 	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
 				     IEEE80211_CHAN_DISABLED))
 		return -EINVAL;
 
-	mutex_lock(&local->chanctx_mtx);
-	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
-					 lockdep_is_held(&local->chanctx_mtx));
-	if (!conf) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ctx = container_of(conf, struct ieee80211_chanctx, conf);
-	if (ctx->refcount != 1) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (ctx->refcount != 1)
+		return -EINVAL;
 
 	if (sdata->vif.bss_conf.chandef.width != chandef->width) {
 		chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH;
@@ -620,7 +601,34 @@ int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
 	ieee80211_recalc_radar_chanctx(local, ctx);
 	ieee80211_recalc_chanctx_min_def(local, ctx);
 
-	ret = 0;
+	return 0;
+}
+
+int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
+				 u32 *changed)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *conf;
+	struct ieee80211_chanctx *ctx;
+	int ret;
+
+	lockdep_assert_held(&local->mtx);
+
+	/* should never be called if not performing a channel switch. */
+	if (WARN_ON(!sdata->vif.csa_active))
+		return -EINVAL;
+
+	mutex_lock(&local->chanctx_mtx);
+	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+					 lockdep_is_held(&local->chanctx_mtx));
+	if (!conf) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ctx = container_of(conf, struct ieee80211_chanctx, conf);
+
+	ret = __ieee80211_vif_change_channel(sdata, ctx, changed);
  out:
 	mutex_unlock(&local->chanctx_mtx);
 	return ret;
-- 
cgit v1.2.3


From 77eeba974fad3046d48697f004de43cae3706927 Mon Sep 17 00:00:00 2001
From: Luciano Coelho <luciano.coelho@intel.com>
Date: Tue, 11 Mar 2014 18:24:12 +0200
Subject: mac80211: refactor ieee80211_assign/unassign_vif_chanctx into one

Combine the functions into one, so that we can switch from one context
to the other without having to unassign and assign separately.  This
is needed by the channel reservation functionality because otherwise
we have a small period of time when the chanctx is set to NULL, which
can cause problems if someone else is trying to dereference it.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 85 +++++++++++++++++++++++++++--------------------------
 1 file changed, 43 insertions(+), 42 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 503ee3083409..35079c8061ae 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -300,32 +300,6 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local,
 	ieee80211_recalc_idle(local);
 }
 
-static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
-					struct ieee80211_chanctx *ctx)
-{
-	struct ieee80211_local *local = sdata->local;
-	int ret;
-
-	lockdep_assert_held(&local->chanctx_mtx);
-
-	ret = drv_assign_vif_chanctx(local, sdata, ctx);
-	if (ret)
-		return ret;
-
-	rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
-	ctx->refcount++;
-
-	ieee80211_recalc_txpower(sdata);
-	ieee80211_recalc_chanctx_min_def(local, ctx);
-	sdata->vif.bss_conf.idle = false;
-
-	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
-	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
-		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
-
-	return 0;
-}
-
 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 					      struct ieee80211_chanctx *ctx)
 {
@@ -384,30 +358,57 @@ static void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
 	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
 }
 
-static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
-					   struct ieee80211_chanctx *ctx)
+static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
+					struct ieee80211_chanctx *new_ctx)
 {
 	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *conf;
+	struct ieee80211_chanctx *curr_ctx = NULL;
+	int ret = 0;
 
-	lockdep_assert_held(&local->chanctx_mtx);
+	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+					 lockdep_is_held(&local->chanctx_mtx));
 
-	ctx->refcount--;
-	RCU_INIT_POINTER(sdata->vif.chanctx_conf, NULL);
+	if (conf) {
+		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-	sdata->vif.bss_conf.idle = true;
+		curr_ctx->refcount--;
+		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
+		conf = NULL;
+	}
 
-	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
-	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
-		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
+	if (new_ctx) {
+		ret = drv_assign_vif_chanctx(local, sdata, new_ctx);
+		if (ret)
+			goto out;
+
+		new_ctx->refcount++;
+		conf = &new_ctx->conf;
+	}
 
-	drv_unassign_vif_chanctx(local, sdata, ctx);
+out:
+	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
+
+	sdata->vif.bss_conf.idle = !conf;
 
-	if (ctx->refcount > 0) {
-		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
-		ieee80211_recalc_smps_chanctx(local, ctx);
-		ieee80211_recalc_radar_chanctx(local, ctx);
-		ieee80211_recalc_chanctx_min_def(local, ctx);
+	if (curr_ctx && curr_ctx->refcount > 0) {
+		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
+		ieee80211_recalc_smps_chanctx(local, curr_ctx);
+		ieee80211_recalc_radar_chanctx(local, curr_ctx);
+		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 	}
+
+	if (new_ctx && new_ctx->refcount > 0) {
+		ieee80211_recalc_txpower(sdata);
+		ieee80211_recalc_chanctx_min_def(local, new_ctx);
+	}
+
+	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
+	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
+		ieee80211_bss_info_change_notify(sdata,
+						 BSS_CHANGED_IDLE);
+
+	return ret;
 }
 
 static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
@@ -425,7 +426,7 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 
 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-	ieee80211_unassign_vif_chanctx(sdata, ctx);
+	ieee80211_assign_vif_chanctx(sdata, NULL);
 	if (ctx->refcount == 0)
 		ieee80211_free_chanctx(local, ctx);
 }
-- 
cgit v1.2.3


From 11335a550b6ac924634f0b77b7a84b6c4f3d8477 Mon Sep 17 00:00:00 2001
From: Luciano Coelho <luciano.coelho@intel.com>
Date: Wed, 30 Oct 2013 13:09:39 +0200
Subject: 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>
---
 net/mac80211/chan.c        | 197 +++++++++++++++++++++++++++++++++++++--------
 net/mac80211/ieee80211_i.h |  13 +++
 2 files changed, 176 insertions(+), 34 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 35079c8061ae..baad75610a6a 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -426,6 +426,9 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 
 	ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
+	if (sdata->reserved_chanctx)
+		ieee80211_vif_unreserve_chanctx(sdata);
+
 	ieee80211_assign_vif_chanctx(sdata, NULL);
 	if (ctx->refcount == 0)
 		ieee80211_free_chanctx(local, ctx);
@@ -635,6 +638,166 @@ int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
 	return ret;
 }
 
+static void
+__ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
+				      bool clear)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *vlan;
+	struct ieee80211_chanctx_conf *conf;
+
+	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
+		return;
+
+	lockdep_assert_held(&local->mtx);
+
+	/* Check that conf exists, even when clearing this function
+	 * must be called with the AP's channel context still there
+	 * as it would otherwise cause VLANs to have an invalid
+	 * channel context pointer for a while, possibly pointing
+	 * to a channel context that has already been freed.
+	 */
+	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+				lockdep_is_held(&local->chanctx_mtx));
+	WARN_ON(!conf);
+
+	if (clear)
+		conf = NULL;
+
+	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
+		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
+}
+
+void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
+					 bool clear)
+{
+	struct ieee80211_local *local = sdata->local;
+
+	mutex_lock(&local->chanctx_mtx);
+
+	__ieee80211_vif_copy_chanctx_to_vlans(sdata, clear);
+
+	mutex_unlock(&local->chanctx_mtx);
+}
+
+int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
+{
+	lockdep_assert_held(&sdata->local->chanctx_mtx);
+
+	if (WARN_ON(!sdata->reserved_chanctx))
+		return -EINVAL;
+
+	if (--sdata->reserved_chanctx->refcount == 0)
+		ieee80211_free_chanctx(sdata->local, sdata->reserved_chanctx);
+
+	sdata->reserved_chanctx = NULL;
+
+	return 0;
+}
+
+int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
+				  const struct cfg80211_chan_def *chandef,
+				  enum ieee80211_chanctx_mode mode)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx_conf *conf;
+	struct ieee80211_chanctx *new_ctx, *curr_ctx;
+	int ret = 0;
+
+	mutex_lock(&local->chanctx_mtx);
+
+	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+					 lockdep_is_held(&local->chanctx_mtx));
+	if (!conf) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
+
+	/* try to find another context with the chandef we want */
+	new_ctx = ieee80211_find_chanctx(local, chandef, mode);
+	if (!new_ctx) {
+		/* create a new context */
+		new_ctx = ieee80211_new_chanctx(local, chandef, mode);
+		if (IS_ERR(new_ctx)) {
+			ret = PTR_ERR(new_ctx);
+			goto out;
+		}
+	}
+
+	new_ctx->refcount++;
+	sdata->reserved_chanctx = new_ctx;
+	sdata->reserved_chandef = *chandef;
+out:
+	mutex_unlock(&local->chanctx_mtx);
+	return ret;
+}
+
+int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
+				       u32 *changed)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_chanctx *ctx;
+	struct ieee80211_chanctx *old_ctx;
+	struct ieee80211_chanctx_conf *conf;
+	int ret;
+	u32 tmp_changed = *changed;
+
+	/* TODO: need to recheck if the chandef is usable etc.? */
+
+	lockdep_assert_held(&local->mtx);
+
+	mutex_lock(&local->chanctx_mtx);
+
+	ctx = sdata->reserved_chanctx;
+	if (WARN_ON(!ctx)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+					 lockdep_is_held(&local->chanctx_mtx));
+	if (!conf) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	old_ctx = container_of(conf, struct ieee80211_chanctx, conf);
+
+	if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width)
+		tmp_changed |= BSS_CHANGED_BANDWIDTH;
+
+	sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
+
+	/* unref our reservation before assigning */
+	ctx->refcount--;
+	sdata->reserved_chanctx = NULL;
+
+	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
+	if (old_ctx->refcount == 0)
+		ieee80211_free_chanctx(local, old_ctx);
+	if (ret) {
+		/* if assign fails refcount stays the same */
+		if (ctx->refcount == 0)
+			ieee80211_free_chanctx(local, ctx);
+		goto out;
+	}
+
+	if (sdata->vif.type == NL80211_IFTYPE_AP)
+		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
+
+	*changed = tmp_changed;
+
+	ieee80211_recalc_chanctx_chantype(local, ctx);
+	ieee80211_recalc_smps_chanctx(local, ctx);
+	ieee80211_recalc_radar_chanctx(local, ctx);
+	ieee80211_recalc_chanctx_min_def(local, ctx);
+out:
+	mutex_unlock(&local->chanctx_mtx);
+	return ret;
+}
+
 int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 				   const struct cfg80211_chan_def *chandef,
 				   u32 *changed)
@@ -714,40 +877,6 @@ void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
 	mutex_unlock(&local->chanctx_mtx);
 }
 
-void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
-					 bool clear)
-{
-	struct ieee80211_local *local = sdata->local;
-	struct ieee80211_sub_if_data *vlan;
-	struct ieee80211_chanctx_conf *conf;
-
-	lockdep_assert_held(&local->mtx);
-
-	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
-		return;
-
-	mutex_lock(&local->chanctx_mtx);
-
-	/*
-	 * Check that conf exists, even when clearing this function
-	 * must be called with the AP's channel context still there
-	 * as it would otherwise cause VLANs to have an invalid
-	 * channel context pointer for a while, possibly pointing
-	 * to a channel context that has already been freed.
-	 */
-	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
-				lockdep_is_held(&local->chanctx_mtx));
-	WARN_ON(!conf);
-
-	if (clear)
-		conf = NULL;
-
-	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
-		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);
-
-	mutex_unlock(&local->chanctx_mtx);
-}
-
 void ieee80211_iter_chan_contexts_atomic(
 	struct ieee80211_hw *hw,
 	void (*iter)(struct ieee80211_hw *hw,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c422f81d93ae..3dd21116332f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -756,6 +756,10 @@ struct ieee80211_sub_if_data {
 	bool csa_radar_required;
 	struct cfg80211_chan_def csa_chandef;
 
+	/* context reservation -- protected with chanctx_mtx */
+	struct ieee80211_chanctx *reserved_chanctx;
+	struct cfg80211_chan_def reserved_chandef;
+
 	/* used to reconfigure hardware SM PS */
 	struct work_struct recalc_smps;
 
@@ -1770,6 +1774,15 @@ int __must_check
 ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 			  const struct cfg80211_chan_def *chandef,
 			  enum ieee80211_chanctx_mode mode);
+int __must_check
+ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
+			      const struct cfg80211_chan_def *chandef,
+			      enum ieee80211_chanctx_mode mode);
+int __must_check
+ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
+				   u32 *changed);
+int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata);
+
 int __must_check
 ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
 			       const struct cfg80211_chan_def *chandef,
-- 
cgit v1.2.3


From 5d52ee81101943c507f45c76368026935f6bb75a Mon Sep 17 00:00:00 2001
From: Luciano Coelho <luciano.coelho@intel.com>
Date: Thu, 27 Feb 2014 14:33:47 +0200
Subject: mac80211: allow reservation of a running chanctx

With single-channel drivers, we need to be able to change a running
chanctx if we want to use chanctx reservation.  Not all drivers may be
able to do this, so add a flag that indicates support for it.

Changing a running chanctx can also be used as an optimization in
multi-channel drivers when the context needs to be reserved for future
usage.

Introduce IEEE80211_CHANCTX_RESERVED chanctx mode to mark a channel as
reserved so nobody else can use it (since we know it's going to
change).  In the future, we may allow several vifs to use the same
reservation as long as they plan to use the chanctx on the same
future channel.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/mac80211.h |  7 +++++
 net/mac80211/chan.c    | 79 ++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 68 insertions(+), 18 deletions(-)

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

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index faa7b9cf9cc7..03ab3c08fb70 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1555,6 +1555,12 @@ struct ieee80211_tx_control {
  *	for a single active channel while using channel contexts. When support
  *	is not enabled the default action is to disconnect when getting the
  *	CSA frame.
+ *
+ * @IEEE80211_HW_CHANGE_RUNNING_CHANCTX: The hardware can change a
+ *	channel context on-the-fly.  This is needed for channel switch
+ *	on single-channel hardware.  It can also be used as an
+ *	optimization in certain channel switch cases with
+ *	multi-channel.
  */
 enum ieee80211_hw_flags {
 	IEEE80211_HW_HAS_RATE_CONTROL			= 1<<0,
@@ -1586,6 +1592,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_TIMING_BEACON_ONLY			= 1<<26,
 	IEEE80211_HW_SUPPORTS_HT_CCK_RATES		= 1<<27,
 	IEEE80211_HW_CHANCTX_STA_CSA			= 1<<28,
+	IEEE80211_HW_CHANGE_RUNNING_CHANCTX		= 1<<29,
 };
 
 /**
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index baad75610a6a..57b8ab1bc5c1 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -168,6 +168,27 @@ static void ieee80211_change_chanctx(struct ieee80211_local *local,
 	}
 }
 
+static bool ieee80211_chanctx_is_reserved(struct ieee80211_local *local,
+					  struct ieee80211_chanctx *ctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	bool ret = false;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+	rcu_read_lock();
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+		if (sdata->reserved_chanctx == ctx) {
+			ret = true;
+			break;
+		}
+	}
+
+	rcu_read_unlock();
+	return ret;
+}
+
 static struct ieee80211_chanctx *
 ieee80211_find_chanctx(struct ieee80211_local *local,
 		       const struct cfg80211_chan_def *chandef,
@@ -183,7 +204,12 @@ ieee80211_find_chanctx(struct ieee80211_local *local,
 	list_for_each_entry(ctx, &local->chanctx_list, list) {
 		const struct cfg80211_chan_def *compat;
 
-		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
+		/* We don't support chanctx reservation for multiple
+		 * vifs yet, so don't allow reserved chanctxs to be
+		 * reused.
+		 */
+		if ((ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) ||
+		    ieee80211_chanctx_is_reserved(local, ctx))
 			continue;
 
 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
@@ -718,11 +744,20 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 	/* try to find another context with the chandef we want */
 	new_ctx = ieee80211_find_chanctx(local, chandef, mode);
 	if (!new_ctx) {
-		/* create a new context */
-		new_ctx = ieee80211_new_chanctx(local, chandef, mode);
-		if (IS_ERR(new_ctx)) {
-			ret = PTR_ERR(new_ctx);
-			goto out;
+		if (curr_ctx->refcount == 1 &&
+		    (local->hw.flags & IEEE80211_HW_CHANGE_RUNNING_CHANCTX)) {
+			/* if we're the only users of the chanctx and
+			 * the driver supports changing a running
+			 * context, reserve our current context
+			 */
+			new_ctx = curr_ctx;
+		} else {
+			/* create a new context and reserve it */
+			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
+			if (IS_ERR(new_ctx)) {
+				ret = PTR_ERR(new_ctx);
+				goto out;
+			}
 		}
 	}
 
@@ -770,22 +805,30 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 
 	sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
 
-	/* unref our reservation before assigning */
+	/* unref our reservation */
 	ctx->refcount--;
 	sdata->reserved_chanctx = NULL;
 
-	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
-	if (old_ctx->refcount == 0)
-		ieee80211_free_chanctx(local, old_ctx);
-	if (ret) {
-		/* if assign fails refcount stays the same */
-		if (ctx->refcount == 0)
-			ieee80211_free_chanctx(local, ctx);
-		goto out;
-	}
+	if (old_ctx == ctx) {
+		/* This is our own context, just change it */
+		ret = __ieee80211_vif_change_channel(sdata, old_ctx,
+						     &tmp_changed);
+		if (ret)
+			goto out;
+	} else {
+		ret = ieee80211_assign_vif_chanctx(sdata, ctx);
+		if (old_ctx->refcount == 0)
+			ieee80211_free_chanctx(local, old_ctx);
+		if (ret) {
+			/* if assign fails refcount stays the same */
+			if (ctx->refcount == 0)
+				ieee80211_free_chanctx(local, ctx);
+			goto out;
+		}
 
-	if (sdata->vif.type == NL80211_IFTYPE_AP)
-		__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
+		if (sdata->vif.type == NL80211_IFTYPE_AP)
+			__ieee80211_vif_copy_chanctx_to_vlans(sdata, false);
+	}
 
 	*changed = tmp_changed;
 
-- 
cgit v1.2.3


From c2b90ad8800db308cdc0db9750c7c0baa07f40d0 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:24 +0200
Subject: mac80211: prevent chanctx overcommit

Do not allocate more channel contexts than a
driver is capable for currently matching interface
combination.

This allows the ieee80211_vif_reserve_chanctx() to
act as a guard against breaking interface
combinations.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 57b8ab1bc5c1..fcb2cd8ffd07 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -9,6 +9,25 @@
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 
+static int ieee80211_num_chanctx(struct ieee80211_local *local)
+{
+	struct ieee80211_chanctx *ctx;
+	int num = 0;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	list_for_each_entry(ctx, &local->chanctx_list, list)
+		num++;
+
+	return num;
+}
+
+static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
+{
+	lockdep_assert_held(&local->chanctx_mtx);
+	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
+}
+
 static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
 {
 	switch (sta->bandwidth) {
@@ -751,13 +770,16 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 			 * context, reserve our current context
 			 */
 			new_ctx = curr_ctx;
-		} else {
+		} else if (ieee80211_can_create_new_chanctx(local)) {
 			/* create a new context and reserve it */
 			new_ctx = ieee80211_new_chanctx(local, chandef, mode);
 			if (IS_ERR(new_ctx)) {
 				ret = PTR_ERR(new_ctx);
 				goto out;
 			}
+		} else {
+			ret = -EBUSY;
+			goto out;
 		}
 	}
 
-- 
cgit v1.2.3


From 093324816b91c9f4a3dd8c78930e43d0a2ef2508 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:25 +0200
Subject: mac80211: add support for radar detection for reservations

Initial chanctx reservation code wasn't aware of
radar detection requirements. This is necessary
for chanctx reservations to be used for channel
switching in the future.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c        | 5 ++++-
 net/mac80211/ieee80211_i.h | 4 +++-
 2 files changed, 7 insertions(+), 2 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index fcb2cd8ffd07..4ed229c0966a 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -742,7 +742,8 @@ int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 
 int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 				  const struct cfg80211_chan_def *chandef,
-				  enum ieee80211_chanctx_mode mode)
+				  enum ieee80211_chanctx_mode mode,
+				  bool radar_required)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_chanctx_conf *conf;
@@ -786,6 +787,7 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 	new_ctx->refcount++;
 	sdata->reserved_chanctx = new_ctx;
 	sdata->reserved_chandef = *chandef;
+	sdata->reserved_radar_required = radar_required;
 out:
 	mutex_unlock(&local->chanctx_mtx);
 	return ret;
@@ -830,6 +832,7 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 	/* unref our reservation */
 	ctx->refcount--;
 	sdata->reserved_chanctx = NULL;
+	sdata->radar_required = sdata->reserved_radar_required;
 
 	if (old_ctx == ctx) {
 		/* This is our own context, just change it */
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index bfc3ca506fbd..4018ba13c028 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -759,6 +759,7 @@ struct ieee80211_sub_if_data {
 	/* context reservation -- protected with chanctx_mtx */
 	struct ieee80211_chanctx *reserved_chanctx;
 	struct cfg80211_chan_def reserved_chandef;
+	bool reserved_radar_required;
 
 	/* used to reconfigure hardware SM PS */
 	struct work_struct recalc_smps;
@@ -1777,7 +1778,8 @@ ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 int __must_check
 ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 			      const struct cfg80211_chan_def *chandef,
-			      enum ieee80211_chanctx_mode mode);
+			      enum ieee80211_chanctx_mode mode,
+			      bool radar_required);
 int __must_check
 ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 				   u32 *changed);
-- 
cgit v1.2.3


From 484298ad1afaf249a4708a5091487132dae80bf9 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:26 +0200
Subject: mac80211: track assigned vifs in chanctx

This can be useful. Provides a more straghtforward
way to iterate over interfaces bound to a given
chanctx and allows tracking chanctx usage
explicitly.

The structure is protected by local->chanctx_mtx.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c        | 4 ++++
 net/mac80211/ieee80211_i.h | 4 ++++
 net/mac80211/iface.c       | 1 +
 3 files changed, 9 insertions(+)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 4ed229c0966a..504526c97867 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -276,6 +276,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
 
+	INIT_LIST_HEAD(&ctx->assigned_vifs);
 	ctx->conf.def = *chandef;
 	ctx->conf.rx_chains_static = 1;
 	ctx->conf.rx_chains_dynamic = 1;
@@ -420,6 +421,7 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 		curr_ctx->refcount--;
 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 		conf = NULL;
+		list_del(&sdata->assigned_chanctx_list);
 	}
 
 	if (new_ctx) {
@@ -429,6 +431,8 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 
 		new_ctx->refcount++;
 		conf = &new_ctx->conf;
+		list_add(&sdata->assigned_chanctx_list,
+			 &new_ctx->assigned_vifs);
 	}
 
 out:
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4018ba13c028..3b3b45a21501 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -691,6 +691,8 @@ struct ieee80211_chanctx {
 	struct list_head list;
 	struct rcu_head rcu_head;
 
+	struct list_head assigned_vifs;
+
 	enum ieee80211_chanctx_mode mode;
 	int refcount;
 	bool driver_present;
@@ -756,6 +758,8 @@ struct ieee80211_sub_if_data {
 	bool csa_radar_required;
 	struct cfg80211_chan_def csa_chandef;
 
+	struct list_head assigned_chanctx_list; /* protected by chanctx_mtx */
+
 	/* context reservation -- protected with chanctx_mtx */
 	struct ieee80211_chanctx *reserved_chanctx;
 	struct cfg80211_chan_def reserved_chandef;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 90b60633a27a..a562d0f489e1 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1291,6 +1291,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 	INIT_WORK(&sdata->work, ieee80211_iface_work);
 	INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);
 	INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work);
+	INIT_LIST_HEAD(&sdata->assigned_chanctx_list);
 
 	switch (type) {
 	case NL80211_IFTYPE_P2P_GO:
-- 
cgit v1.2.3


From e3afb920227d37fe72914350c41621c028539077 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:27 +0200
Subject: mac80211: track reserved vifs in chanctx

This can be useful. Provides a more straghtforward
way to iterate over interfaces taking part in
chanctx reservation and allows tracking chanctx
usage explicitly.

The structure is protected by local->chanctx_mtx.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c        | 14 ++++++++++----
 net/mac80211/ieee80211_i.h |  2 ++
 net/mac80211/iface.c       |  1 +
 3 files changed, 13 insertions(+), 4 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 504526c97867..79eac96d9e5f 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -277,6 +277,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 		return ERR_PTR(-ENOMEM);
 
 	INIT_LIST_HEAD(&ctx->assigned_vifs);
+	INIT_LIST_HEAD(&ctx->reserved_vifs);
 	ctx->conf.def = *chandef;
 	ctx->conf.rx_chains_static = 1;
 	ctx->conf.rx_chains_dynamic = 1;
@@ -731,16 +732,19 @@ void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 
 int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 {
+	struct ieee80211_chanctx *ctx = sdata->reserved_chanctx;
+
 	lockdep_assert_held(&sdata->local->chanctx_mtx);
 
-	if (WARN_ON(!sdata->reserved_chanctx))
+	if (WARN_ON(!ctx))
 		return -EINVAL;
 
-	if (--sdata->reserved_chanctx->refcount == 0)
-		ieee80211_free_chanctx(sdata->local, sdata->reserved_chanctx);
-
+	list_del(&sdata->reserved_chanctx_list);
 	sdata->reserved_chanctx = NULL;
 
+	if (--ctx->refcount == 0)
+		ieee80211_free_chanctx(sdata->local, ctx);
+
 	return 0;
 }
 
@@ -788,6 +792,7 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 		}
 	}
 
+	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
 	new_ctx->refcount++;
 	sdata->reserved_chanctx = new_ctx;
 	sdata->reserved_chandef = *chandef;
@@ -837,6 +842,7 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 	ctx->refcount--;
 	sdata->reserved_chanctx = NULL;
 	sdata->radar_required = sdata->reserved_radar_required;
+	list_del(&sdata->reserved_chanctx_list);
 
 	if (old_ctx == ctx) {
 		/* This is our own context, just change it */
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3b3b45a21501..3eaf6d7fad52 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -692,6 +692,7 @@ struct ieee80211_chanctx {
 	struct rcu_head rcu_head;
 
 	struct list_head assigned_vifs;
+	struct list_head reserved_vifs;
 
 	enum ieee80211_chanctx_mode mode;
 	int refcount;
@@ -759,6 +760,7 @@ struct ieee80211_sub_if_data {
 	struct cfg80211_chan_def csa_chandef;
 
 	struct list_head assigned_chanctx_list; /* protected by chanctx_mtx */
+	struct list_head reserved_chanctx_list; /* protected by chanctx_mtx */
 
 	/* context reservation -- protected with chanctx_mtx */
 	struct ieee80211_chanctx *reserved_chanctx;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index a562d0f489e1..e91569d887e3 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1292,6 +1292,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 	INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work);
 	INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work);
 	INIT_LIST_HEAD(&sdata->assigned_chanctx_list);
+	INIT_LIST_HEAD(&sdata->reserved_chanctx_list);
 
 	switch (type) {
 	case NL80211_IFTYPE_P2P_GO:
-- 
cgit v1.2.3


From 0288157b2ad085e564fb563fbe7794c9ffae4169 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:28 +0200
Subject: mac80211: improve find_chanctx() for reservations

This allows new vifs to be assigned to a chanctx
as long as chanctx's reservation chandefs (if any)
and chanctx's current chandef (implied by assigned
vifs at the time, if any) and the new vif chandef
are all compatible.

This implies it is impossible to assign a new vif
to an in-place reservation chanctx.

This gives no advantages for single-channel
hardware. It makes sense for multi-channel
hardware only.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 56 +++++++++++++++++++++++++++--------------------------
 1 file changed, 29 insertions(+), 27 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 79eac96d9e5f..0dfb04a07f30 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -28,6 +28,29 @@ static bool ieee80211_can_create_new_chanctx(struct ieee80211_local *local)
 	return ieee80211_num_chanctx(local) < ieee80211_max_num_channels(local);
 }
 
+static const struct cfg80211_chan_def *
+ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *ctx,
+				   const struct cfg80211_chan_def *compat)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	list_for_each_entry(sdata, &ctx->reserved_vifs,
+			    reserved_chanctx_list) {
+		if (!compat)
+			compat = &sdata->reserved_chandef;
+
+		compat = cfg80211_chandef_compatible(&sdata->reserved_chandef,
+						     compat);
+		if (!compat)
+			break;
+	}
+
+	return compat;
+}
+
 static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
 {
 	switch (sta->bandwidth) {
@@ -187,27 +210,6 @@ static void ieee80211_change_chanctx(struct ieee80211_local *local,
 	}
 }
 
-static bool ieee80211_chanctx_is_reserved(struct ieee80211_local *local,
-					  struct ieee80211_chanctx *ctx)
-{
-	struct ieee80211_sub_if_data *sdata;
-	bool ret = false;
-
-	lockdep_assert_held(&local->chanctx_mtx);
-	rcu_read_lock();
-	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
-		if (!ieee80211_sdata_running(sdata))
-			continue;
-		if (sdata->reserved_chanctx == ctx) {
-			ret = true;
-			break;
-		}
-	}
-
-	rcu_read_unlock();
-	return ret;
-}
-
 static struct ieee80211_chanctx *
 ieee80211_find_chanctx(struct ieee80211_local *local,
 		       const struct cfg80211_chan_def *chandef,
@@ -223,18 +225,18 @@ ieee80211_find_chanctx(struct ieee80211_local *local,
 	list_for_each_entry(ctx, &local->chanctx_list, list) {
 		const struct cfg80211_chan_def *compat;
 
-		/* We don't support chanctx reservation for multiple
-		 * vifs yet, so don't allow reserved chanctxs to be
-		 * reused.
-		 */
-		if ((ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) ||
-		    ieee80211_chanctx_is_reserved(local, ctx))
+		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
 			continue;
 
 		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
 		if (!compat)
 			continue;
 
+		compat = ieee80211_chanctx_reserved_chandef(local, ctx,
+							    compat);
+		if (!compat)
+			continue;
+
 		ieee80211_change_chanctx(local, ctx, compat);
 
 		return ctx;
-- 
cgit v1.2.3


From 13f348a814e75667a9cc0b00f9a87dae5ab9b943 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:29 +0200
Subject: mac80211: improve chanctx reservation lookup

Use a separate function to look for reservation
chanctx. For multi-interface/channel reservation
search sematics differ slightly.

The new routine allows reservations to be merged
with chanctx that are already reserved by other
interface(s).

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 88 insertions(+), 2 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 0dfb04a07f30..7303eddb1895 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -51,6 +51,93 @@ ieee80211_chanctx_reserved_chandef(struct ieee80211_local *local,
 	return compat;
 }
 
+static const struct cfg80211_chan_def *
+ieee80211_chanctx_non_reserved_chandef(struct ieee80211_local *local,
+				       struct ieee80211_chanctx *ctx,
+				       const struct cfg80211_chan_def *compat)
+{
+	struct ieee80211_sub_if_data *sdata;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	list_for_each_entry(sdata, &ctx->assigned_vifs,
+			    assigned_chanctx_list) {
+		if (sdata->reserved_chanctx != NULL)
+			continue;
+
+		if (!compat)
+			compat = &sdata->vif.bss_conf.chandef;
+
+		compat = cfg80211_chandef_compatible(
+				&sdata->vif.bss_conf.chandef, compat);
+		if (!compat)
+			break;
+	}
+
+	return compat;
+}
+
+static const struct cfg80211_chan_def *
+ieee80211_chanctx_combined_chandef(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *ctx,
+				   const struct cfg80211_chan_def *compat)
+{
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	compat = ieee80211_chanctx_reserved_chandef(local, ctx, compat);
+	if (!compat)
+		return NULL;
+
+	compat = ieee80211_chanctx_non_reserved_chandef(local, ctx, compat);
+	if (!compat)
+		return NULL;
+
+	return compat;
+}
+
+static bool
+ieee80211_chanctx_can_reserve_chandef(struct ieee80211_local *local,
+				      struct ieee80211_chanctx *ctx,
+				      const struct cfg80211_chan_def *def)
+{
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	if (ieee80211_chanctx_combined_chandef(local, ctx, def))
+		return true;
+
+	if (!list_empty(&ctx->reserved_vifs) &&
+	    ieee80211_chanctx_reserved_chandef(local, ctx, def))
+		return true;
+
+	return false;
+}
+
+static struct ieee80211_chanctx *
+ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
+				   const struct cfg80211_chan_def *chandef,
+				   enum ieee80211_chanctx_mode mode)
+{
+	struct ieee80211_chanctx *ctx;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
+		return NULL;
+
+	list_for_each_entry(ctx, &local->chanctx_list, list) {
+		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
+			continue;
+
+		if (!ieee80211_chanctx_can_reserve_chandef(local, ctx,
+							   chandef))
+			continue;
+
+		return ctx;
+	}
+
+	return NULL;
+}
+
 static enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
 {
 	switch (sta->bandwidth) {
@@ -771,8 +858,7 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 
 	curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-	/* try to find another context with the chandef we want */
-	new_ctx = ieee80211_find_chanctx(local, chandef, mode);
+	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 	if (!new_ctx) {
 		if (curr_ctx->refcount == 1 &&
 		    (local->hw.flags & IEEE80211_HW_CHANGE_RUNNING_CHANCTX)) {
-- 
cgit v1.2.3


From ed68ebcaf9688a15cbd249476334d37717d49468 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:30 +0200
Subject: mac80211: split ieee80211_new_chanctx()

The function did a little too much. Split it up so
the code can be easily reused in the future.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 56 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 13 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 7303eddb1895..247133fe36bc 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -351,19 +351,17 @@ static bool ieee80211_is_radar_required(struct ieee80211_local *local)
 }
 
 static struct ieee80211_chanctx *
-ieee80211_new_chanctx(struct ieee80211_local *local,
-		      const struct cfg80211_chan_def *chandef,
-		      enum ieee80211_chanctx_mode mode)
+ieee80211_alloc_chanctx(struct ieee80211_local *local,
+			const struct cfg80211_chan_def *chandef,
+			enum ieee80211_chanctx_mode mode)
 {
 	struct ieee80211_chanctx *ctx;
-	u32 changed;
-	int err;
 
 	lockdep_assert_held(&local->chanctx_mtx);
 
 	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
 	if (!ctx)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	INIT_LIST_HEAD(&ctx->assigned_vifs);
 	INIT_LIST_HEAD(&ctx->reserved_vifs);
@@ -373,31 +371,63 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 	ctx->mode = mode;
 	ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
 	ieee80211_recalc_chanctx_min_def(local, ctx);
+
+	return ctx;
+}
+
+static int ieee80211_add_chanctx(struct ieee80211_local *local,
+				 struct ieee80211_chanctx *ctx)
+{
+	u32 changed;
+	int err;
+
+	lockdep_assert_held(&local->mtx);
+	lockdep_assert_held(&local->chanctx_mtx);
+
 	if (!local->use_chanctx)
 		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;
 
-	/* we hold the mutex to prevent idle from changing */
-	lockdep_assert_held(&local->mtx);
 	/* turn idle off *before* setting channel -- some drivers need that */
 	changed = ieee80211_idle_off(local);
 	if (changed)
 		ieee80211_hw_config(local, changed);
 
 	if (!local->use_chanctx) {
-		local->_oper_chandef = *chandef;
+		local->_oper_chandef = ctx->conf.def;
 		ieee80211_hw_config(local, 0);
 	} else {
 		err = drv_add_chanctx(local, ctx);
 		if (err) {
-			kfree(ctx);
 			ieee80211_recalc_idle(local);
-			return ERR_PTR(err);
+			return err;
 		}
 	}
 
-	/* and keep the mutex held until the new chanctx is on the list */
-	list_add_rcu(&ctx->list, &local->chanctx_list);
+	return 0;
+}
+
+static struct ieee80211_chanctx *
+ieee80211_new_chanctx(struct ieee80211_local *local,
+		      const struct cfg80211_chan_def *chandef,
+		      enum ieee80211_chanctx_mode mode)
+{
+	struct ieee80211_chanctx *ctx;
+	int err;
+
+	lockdep_assert_held(&local->mtx);
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	ctx = ieee80211_alloc_chanctx(local, chandef, mode);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
 
+	err = ieee80211_add_chanctx(local, ctx);
+	if (err) {
+		kfree(ctx);
+		return ERR_PTR(err);
+	}
+
+	list_add_rcu(&ctx->list, &local->chanctx_list);
 	return ctx;
 }
 
-- 
cgit v1.2.3


From 1f0d54cdcf822894cebebaa6cdc4e838c32bfb08 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:31 +0200
Subject: mac80211: split ieee80211_free_chanctx()

The function did a little too much. Split it up so
the code can be easily reused in the future.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 247133fe36bc..e4166b3af5d4 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -431,14 +431,11 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
 	return ctx;
 }
 
-static void ieee80211_free_chanctx(struct ieee80211_local *local,
-				   struct ieee80211_chanctx *ctx)
+static void ieee80211_del_chanctx(struct ieee80211_local *local,
+				  struct ieee80211_chanctx *ctx)
 {
-	bool check_single_channel = false;
 	lockdep_assert_held(&local->chanctx_mtx);
 
-	WARN_ON_ONCE(ctx->refcount != 0);
-
 	if (!local->use_chanctx) {
 		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
 		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
@@ -448,8 +445,9 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local,
 		/* NOTE: Disabling radar is only valid here for
 		 * single channel context. To be sure, check it ...
 		 */
-		if (local->hw.conf.radar_enabled)
-			check_single_channel = true;
+		WARN_ON(local->hw.conf.radar_enabled &&
+			!list_empty(&local->chanctx_list));
+
 		local->hw.conf.radar_enabled = false;
 
 		ieee80211_hw_config(local, 0);
@@ -457,13 +455,19 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local,
 		drv_remove_chanctx(local, ctx);
 	}
 
-	list_del_rcu(&ctx->list);
-	kfree_rcu(ctx, rcu_head);
+	ieee80211_recalc_idle(local);
+}
 
-	/* throw a warning if this wasn't the only channel context. */
-	WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));
+static void ieee80211_free_chanctx(struct ieee80211_local *local,
+				   struct ieee80211_chanctx *ctx)
+{
+	lockdep_assert_held(&local->chanctx_mtx);
 
-	ieee80211_recalc_idle(local);
+	WARN_ON_ONCE(ctx->refcount != 0);
+
+	list_del_rcu(&ctx->list);
+	ieee80211_del_chanctx(local, ctx);
+	kfree_rcu(ctx, rcu_head);
 }
 
 static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
-- 
cgit v1.2.3


From c0166da9fee2aa8de9d1f9460f62d02176c22350 Mon Sep 17 00:00:00 2001
From: Michal Kazior <michal.kazior@tieto.com>
Date: Wed, 9 Apr 2014 15:29:33 +0200
Subject: mac80211: compute chanctx refcount on-the-fly

It doesn't make much sense to store refcount in
the chanctx structure. One still needs to hold
chanctx_mtx to get the value safely. Besides,
refcount isn't on performance critical paths.

This will make implementing chanctx reservation
refcounting a little easier.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/cfg.c         |  2 +-
 net/mac80211/chan.c        | 59 +++++++++++++++++++++++++++++++++++-----------
 net/mac80211/ieee80211_i.h |  3 ++-
 net/mac80211/mlme.c        |  2 +-
 4 files changed, 49 insertions(+), 17 deletions(-)

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

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9620d4fba0d1..4d15a1566cd5 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3251,7 +3251,7 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 
 	/* don't handle for multi-VIF cases */
 	chanctx = container_of(conf, struct ieee80211_chanctx, conf);
-	if (chanctx->refcount > 1) {
+	if (ieee80211_chanctx_refcount(local, chanctx) > 1) {
 		mutex_unlock(&local->chanctx_mtx);
 		return -EBUSY;
 	}
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index e4166b3af5d4..d8b1b8614842 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -9,6 +9,41 @@
 #include "ieee80211_i.h"
 #include "driver-ops.h"
 
+static int ieee80211_chanctx_num_assigned(struct ieee80211_local *local,
+					  struct ieee80211_chanctx *ctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	int num = 0;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	list_for_each_entry(sdata, &ctx->assigned_vifs, assigned_chanctx_list)
+		num++;
+
+	return num;
+}
+
+static int ieee80211_chanctx_num_reserved(struct ieee80211_local *local,
+					  struct ieee80211_chanctx *ctx)
+{
+	struct ieee80211_sub_if_data *sdata;
+	int num = 0;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	list_for_each_entry(sdata, &ctx->reserved_vifs, reserved_chanctx_list)
+		num++;
+
+	return num;
+}
+
+int ieee80211_chanctx_refcount(struct ieee80211_local *local,
+			       struct ieee80211_chanctx *ctx)
+{
+	return ieee80211_chanctx_num_assigned(local, ctx) +
+	       ieee80211_chanctx_num_reserved(local, ctx);
+}
+
 static int ieee80211_num_chanctx(struct ieee80211_local *local)
 {
 	struct ieee80211_chanctx *ctx;
@@ -463,7 +498,7 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local,
 {
 	lockdep_assert_held(&local->chanctx_mtx);
 
-	WARN_ON_ONCE(ctx->refcount != 0);
+	WARN_ON_ONCE(ieee80211_chanctx_refcount(local, ctx) != 0);
 
 	list_del_rcu(&ctx->list);
 	ieee80211_del_chanctx(local, ctx);
@@ -542,7 +577,6 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 	if (conf) {
 		curr_ctx = container_of(conf, struct ieee80211_chanctx, conf);
 
-		curr_ctx->refcount--;
 		drv_unassign_vif_chanctx(local, sdata, curr_ctx);
 		conf = NULL;
 		list_del(&sdata->assigned_chanctx_list);
@@ -553,7 +587,6 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
 		if (ret)
 			goto out;
 
-		new_ctx->refcount++;
 		conf = &new_ctx->conf;
 		list_add(&sdata->assigned_chanctx_list,
 			 &new_ctx->assigned_vifs);
@@ -564,14 +597,14 @@ out:
 
 	sdata->vif.bss_conf.idle = !conf;
 
-	if (curr_ctx && curr_ctx->refcount > 0) {
+	if (curr_ctx && ieee80211_chanctx_num_assigned(local, curr_ctx) > 0) {
 		ieee80211_recalc_chanctx_chantype(local, curr_ctx);
 		ieee80211_recalc_smps_chanctx(local, curr_ctx);
 		ieee80211_recalc_radar_chanctx(local, curr_ctx);
 		ieee80211_recalc_chanctx_min_def(local, curr_ctx);
 	}
 
-	if (new_ctx && new_ctx->refcount > 0) {
+	if (new_ctx && ieee80211_chanctx_num_assigned(local, new_ctx) > 0) {
 		ieee80211_recalc_txpower(sdata);
 		ieee80211_recalc_chanctx_min_def(local, new_ctx);
 	}
@@ -603,7 +636,7 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
 		ieee80211_vif_unreserve_chanctx(sdata);
 
 	ieee80211_assign_vif_chanctx(sdata, NULL);
-	if (ctx->refcount == 0)
+	if (ieee80211_chanctx_refcount(local, ctx) == 0)
 		ieee80211_free_chanctx(local, ctx);
 }
 
@@ -735,7 +768,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
 	if (ret) {
 		/* if assign fails refcount stays the same */
-		if (ctx->refcount == 0)
+		if (ieee80211_chanctx_refcount(local, ctx) == 0)
 			ieee80211_free_chanctx(local, ctx);
 		goto out;
 	}
@@ -759,7 +792,7 @@ static int __ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata,
 				     IEEE80211_CHAN_DISABLED))
 		return -EINVAL;
 
-	if (ctx->refcount != 1)
+	if (ieee80211_chanctx_refcount(local, ctx) != 1)
 		return -EINVAL;
 
 	if (sdata->vif.bss_conf.chandef.width != chandef->width) {
@@ -865,7 +898,7 @@ int ieee80211_vif_unreserve_chanctx(struct ieee80211_sub_if_data *sdata)
 	list_del(&sdata->reserved_chanctx_list);
 	sdata->reserved_chanctx = NULL;
 
-	if (--ctx->refcount == 0)
+	if (ieee80211_chanctx_refcount(sdata->local, ctx) == 0)
 		ieee80211_free_chanctx(sdata->local, ctx);
 
 	return 0;
@@ -894,7 +927,7 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 
 	new_ctx = ieee80211_find_reservation_chanctx(local, chandef, mode);
 	if (!new_ctx) {
-		if (curr_ctx->refcount == 1 &&
+		if (ieee80211_chanctx_refcount(local, curr_ctx) == 1 &&
 		    (local->hw.flags & IEEE80211_HW_CHANGE_RUNNING_CHANCTX)) {
 			/* if we're the only users of the chanctx and
 			 * the driver supports changing a running
@@ -915,7 +948,6 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata,
 	}
 
 	list_add(&sdata->reserved_chanctx_list, &new_ctx->reserved_vifs);
-	new_ctx->refcount++;
 	sdata->reserved_chanctx = new_ctx;
 	sdata->reserved_chandef = *chandef;
 	sdata->reserved_radar_required = radar_required;
@@ -961,7 +993,6 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 	sdata->vif.bss_conf.chandef = sdata->reserved_chandef;
 
 	/* unref our reservation */
-	ctx->refcount--;
 	sdata->reserved_chanctx = NULL;
 	sdata->radar_required = sdata->reserved_radar_required;
 	list_del(&sdata->reserved_chanctx_list);
@@ -974,11 +1005,11 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata,
 			goto out;
 	} else {
 		ret = ieee80211_assign_vif_chanctx(sdata, ctx);
-		if (old_ctx->refcount == 0)
+		if (ieee80211_chanctx_refcount(local, old_ctx) == 0)
 			ieee80211_free_chanctx(local, old_ctx);
 		if (ret) {
 			/* if assign fails refcount stays the same */
-			if (ctx->refcount == 0)
+			if (ieee80211_chanctx_refcount(local, ctx) == 0)
 				ieee80211_free_chanctx(local, ctx);
 			goto out;
 		}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3eaf6d7fad52..b455f62d357a 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -695,7 +695,6 @@ struct ieee80211_chanctx {
 	struct list_head reserved_vifs;
 
 	enum ieee80211_chanctx_mode mode;
-	int refcount;
 	bool driver_present;
 
 	struct ieee80211_chanctx_conf conf;
@@ -1803,6 +1802,8 @@ void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata);
 void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata);
 void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 					 bool clear);
+int ieee80211_chanctx_refcount(struct ieee80211_local *local,
+			       struct ieee80211_chanctx *ctx);
 
 void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
 				   struct ieee80211_chanctx *chanctx);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index dee50aefd6e8..98755ce49af3 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1089,7 +1089,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 	}
 	chanctx = container_of(rcu_access_pointer(sdata->vif.chanctx_conf),
 			       struct ieee80211_chanctx, conf);
-	if (chanctx->refcount > 1) {
+	if (ieee80211_chanctx_refcount(local, chanctx) > 1) {
 		sdata_info(sdata,
 			   "channel switch with multiple interfaces on the same channel, disconnecting\n");
 		ieee80211_queue_work(&local->hw,
-- 
cgit v1.2.3


From 33926eb7785ac7ce7d45d1ae5afb0780a4270342 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 9 Apr 2014 21:31:13 +0200
Subject: mac80211: mark local variable __maybe_unused

The 'local' variable in __ieee80211_vif_copy_chanctx_to_vlans()
is only used/needed when lockdep is compiled in, mark it as such
to avoid compile warnings in the other case.

While at it, fix some indentation where it's used.

Reviewed-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/chan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index d8b1b8614842..3702d642cd8f 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -848,7 +848,7 @@ static void
 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 				      bool clear)
 {
-	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_local *local __maybe_unused = sdata->local;
 	struct ieee80211_sub_if_data *vlan;
 	struct ieee80211_chanctx_conf *conf;
 
@@ -864,7 +864,7 @@ __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 	 * to a channel context that has already been freed.
 	 */
 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
-				lockdep_is_held(&local->chanctx_mtx));
+					 lockdep_is_held(&local->chanctx_mtx));
 	WARN_ON(!conf);
 
 	if (clear)
-- 
cgit v1.2.3