[RFC] mac80211: make powersave independent of interface type

* [RFC] mac80211: make powersave independent of interface type
@ 2012-10-08 18:07 Marco Porsch
  2012-10-09 18:39 ` Johannes Berg
  0 siblings, 1 reply; 5+ messages in thread
From: Marco Porsch @ 2012-10-08 18:07 UTC (permalink / raw)
  To: johannes; +Cc: linux-wireless, Marco Porsch

This patch prepares mac80211 for a later implementation of mesh or ad-hoc
powersave.
The structures related to powersave (buffer, TIM map, counters) are moved
from the AP-specific interface structure to a generic structure that can
be embedded into any interface type.
The functions related to powersave are prepared to allow easy extension
with different interface types. For example with:

+ } else if (sta->sdata->vif.type == NL80211_IFTYPE_MESH_POINT) {
+			ps = &sdata->u.mesh.ps;


Some references to the AP's beacon structure are removed where they were
obviously not used. Other occurrences are in ieee80211_get_buffered_bc
where I am not sure if they make any sense or not. Should they be removed
too?

Does it make any sense to test for NL80211_IFTYPE_AP and
NL80211_IFTYPE_AP_VLAN everytime?

The patch compiles without warning and has been briefly tested as AP
interface with one client in PS mode.


Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
---
 net/mac80211/debugfs_netdev.c |    6 +--
 net/mac80211/ieee80211_i.h    |   20 +++++----
 net/mac80211/iface.c          |    6 +--
 net/mac80211/rx.c             |   21 ++++++---
 net/mac80211/sta_info.c       |   45 ++++++++++++++-----
 net/mac80211/tx.c             |  100 ++++++++++++++++++++++++-----------------
 6 files changed, 124 insertions(+), 74 deletions(-)

diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 6d5aec9..c83b8ca 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -395,14 +395,14 @@ __IEEE80211_IF_FILE_W(uapsd_max_sp_len);
 
 /* AP attributes */
 IEEE80211_IF_FILE(num_mcast_sta, u.ap.num_mcast_sta, ATOMIC);
-IEEE80211_IF_FILE(num_sta_ps, u.ap.num_sta_ps, ATOMIC);
-IEEE80211_IF_FILE(dtim_count, u.ap.dtim_count, DEC);
+IEEE80211_IF_FILE(num_sta_ps, u.ap.ps.num_sta_ps, ATOMIC);
+IEEE80211_IF_FILE(dtim_count, u.ap.ps.dtim_count, DEC);
 
 static ssize_t ieee80211_if_fmt_num_buffered_multicast(
 	const struct ieee80211_sub_if_data *sdata, char *buf, int buflen)
 {
 	return scnprintf(buf, buflen, "%u\n",
-			 skb_queue_len(&sdata->u.ap.ps_bc_buf));
+			 skb_queue_len(&sdata->u.ap.ps.bc_buf));
 }
 __IEEE80211_IF_FILE(num_buffered_multicast, NULL);
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8c80455..c430302 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -280,23 +280,27 @@ struct probe_resp {
 	u8 data[0];
 };
 
-struct ieee80211_if_ap {
-	struct beacon_data __rcu *beacon;
-	struct probe_resp __rcu *probe_resp;
-
-	struct list_head vlans;
-
+struct ps_data {
 	/* yes, this looks ugly, but guarantees that we can later use
 	 * bitmap_empty :)
 	 * NB: don't touch this bitmap, use sta_info_{set,clear}_tim_bit */
 	u8 tim[sizeof(unsigned long) * BITS_TO_LONGS(IEEE80211_MAX_AID + 1)];
-	struct sk_buff_head ps_bc_buf;
+	struct sk_buff_head bc_buf;
 	atomic_t num_sta_ps; /* number of stations in PS mode */
-	atomic_t num_mcast_sta; /* number of stations receiving multicast */
 	int dtim_count;
 	bool dtim_bc_mc;
 };
 
+struct ieee80211_if_ap {
+	struct beacon_data __rcu *beacon;
+	struct probe_resp __rcu *probe_resp;
+
+	struct list_head vlans;
+
+	struct ps_data ps;
+	atomic_t num_mcast_sta; /* number of stations receiving multicast */
+};
+
 struct ieee80211_if_wds {
 	struct sta_info *sta;
 	u8 remote_addr[ETH_ALEN];
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 6f8a73c..f41b5cf 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -755,8 +755,8 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 		WARN_ON(!list_empty(&sdata->u.ap.vlans));
 
 		/* free all potentially still buffered bcast frames */
-		local->total_ps_buffered -= skb_queue_len(&sdata->u.ap.ps_bc_buf);
-		skb_queue_purge(&sdata->u.ap.ps_bc_buf);
+		local->total_ps_buffered -= skb_queue_len(&sdata->u.ap.ps.bc_buf);
+		skb_queue_purge(&sdata->u.ap.ps.bc_buf);
 	} else if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 		ieee80211_mgd_stop(sdata);
 	}
@@ -1157,7 +1157,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 		sdata->vif.p2p = true;
 		/* fall through */
 	case NL80211_IFTYPE_AP:
-		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
+		skb_queue_head_init(&sdata->u.ap.ps.bc_buf);
 		INIT_LIST_HEAD(&sdata->u.ap.vlans);
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 61c621e..0573b1b 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1141,12 +1141,19 @@ ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 	return RX_CONTINUE;
 }
 
-static void ap_sta_ps_start(struct sta_info *sta)
+static void sta_ps_start(struct sta_info *sta)
 {
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct ieee80211_local *local = sdata->local;
+	struct ps_data *ps;
 
-	atomic_inc(&sdata->bss->num_sta_ps);
+	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
+	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+		ps = &sdata->bss->ps;
+	else
+		return;
+
+	atomic_inc(&ps->num_sta_ps);
 	set_sta_flag(sta, WLAN_STA_PS_STA);
 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
 		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
@@ -1154,7 +1161,7 @@ static void ap_sta_ps_start(struct sta_info *sta)
 	       sta->sta.addr, sta->sta.aid);
 }
 
-static void ap_sta_ps_end(struct sta_info *sta)
+static void sta_ps_end(struct sta_info *sta)
 {
 	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
 	       sta->sta.addr, sta->sta.aid);
@@ -1181,9 +1188,9 @@ int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
 		return -EINVAL;
 
 	if (start)
-		ap_sta_ps_start(sta_inf);
+		sta_ps_start(sta_inf);
 	else
-		ap_sta_ps_end(sta_inf);
+		sta_ps_end(sta_inf);
 
 	return 0;
 }
@@ -1335,10 +1342,10 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 			 */
 			if (ieee80211_is_data(hdr->frame_control) &&
 			    !ieee80211_has_pm(hdr->frame_control))
-				ap_sta_ps_end(sta);
+				sta_ps_end(sta);
 		} else {
 			if (ieee80211_has_pm(hdr->frame_control))
-				ap_sta_ps_start(sta);
+				sta_ps_start(sta);
 		}
 	}
 
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 797dd36..9e609f1 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -98,6 +98,7 @@ static void free_sta_work(struct work_struct *wk)
 	struct tid_ampdu_tx *tid_tx;
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct ieee80211_local *local = sdata->local;
+	struct ps_data *ps;
 
 	/*
 	 * At this point, when being called as call_rcu callback,
@@ -107,11 +108,17 @@ static void free_sta_work(struct work_struct *wk)
 	 */
 
 	if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
-		BUG_ON(!sdata->bss);
+		if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
+		    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+			BUG_ON(!sdata->bss);
+			ps = &sdata->bss->ps;
+		} else {
+			return;
+		}
 
 		clear_sta_flag(sta, WLAN_STA_PS_STA);
 
-		atomic_dec(&sdata->bss->num_sta_ps);
+		atomic_dec(&ps->num_sta_ps);
 		sta_info_recalc_tim(sta);
 	}
 
@@ -502,22 +509,22 @@ int sta_info_insert(struct sta_info *sta)
 	return err;
 }
 
-static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
+static inline void __bss_tim_set(u8 *tim, u16 id)
 {
 	/*
 	 * This format has been mandated by the IEEE specifications,
 	 * so this line may not be changed to use the __set_bit() format.
 	 */
-	bss->tim[aid / 8] |= (1 << (aid % 8));
+	tim[id / 8] |= (1 << (id % 8));
 }
 
-static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
+static inline void __bss_tim_clear(u8 *tim, u16 id)
 {
 	/*
 	 * This format has been mandated by the IEEE specifications,
 	 * so this line may not be changed to use the __clear_bit() format.
 	 */
-	bss->tim[aid / 8] &= ~(1 << (aid % 8));
+	tim[id / 8] &= ~(1 << (id % 8));
 }
 
 static unsigned long ieee80211_tids_for_ac(int ac)
@@ -541,14 +548,23 @@ static unsigned long ieee80211_tids_for_ac(int ac)
 void sta_info_recalc_tim(struct sta_info *sta)
 {
 	struct ieee80211_local *local = sta->local;
-	struct ieee80211_if_ap *bss = sta->sdata->bss;
+	struct ps_data *ps;
 	unsigned long flags;
 	bool indicate_tim = false;
 	u8 ignore_for_tim = sta->sta.uapsd_queues;
 	int ac;
+	u16 id;
+
+	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
+	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+		if (WARN_ON_ONCE(!sta->sdata->bss))
+			return;
 
-	if (WARN_ON_ONCE(!sta->sdata->bss))
+		ps = &sta->sdata->bss->ps;
+		id = sta->sta.aid;
+	} else {
 		return;
+	}
 
 	/* No need to do anything if the driver does all */
 	if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
@@ -587,9 +603,9 @@ void sta_info_recalc_tim(struct sta_info *sta)
 	spin_lock_irqsave(&local->tim_lock, flags);
 
 	if (indicate_tim)
-		__bss_tim_set(bss, sta->sta.aid);
+		__bss_tim_set(ps->tim, id);
 	else
-		__bss_tim_clear(bss, sta->sta.aid);
+		__bss_tim_clear(ps->tim, id);
 
 	if (local->ops->set_tim) {
 		local->tim_in_locked_section = true;
@@ -948,10 +964,17 @@ static void clear_sta_ps_flags(void *_sta)
 {
 	struct sta_info *sta = _sta;
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
+	struct ps_data *ps;
+
+	if (sdata->vif.type == NL80211_IFTYPE_AP ||
+	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+		ps = &sdata->bss->ps;
+	else
+		return;
 
 	clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
 	if (test_and_clear_sta_flag(sta, WLAN_STA_PS_STA))
-		atomic_dec(&sdata->bss->num_sta_ps);
+		atomic_dec(&ps->num_sta_ps);
 }
 
 /* powersave support code */
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index e0e0d1d..ac9f771 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -330,16 +330,19 @@ static void purge_old_ps_buffers(struct ieee80211_local *local)
 	rcu_read_lock();
 
 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
-		struct ieee80211_if_ap *ap;
-		if (sdata->vif.type != NL80211_IFTYPE_AP)
+		struct ps_data *ps;
+
+		if (sdata->vif.type == NL80211_IFTYPE_AP)
+			ps = &sdata->u.ap.ps;
+		else
 			continue;
-		ap = &sdata->u.ap;
-		skb = skb_dequeue(&ap->ps_bc_buf);
+
+		skb = skb_dequeue(&ps->bc_buf);
 		if (skb) {
 			purged++;
 			dev_kfree_skb(skb);
 		}
-		total += skb_queue_len(&ap->ps_bc_buf);
+		total += skb_queue_len(&ps->bc_buf);
 	}
 
 	/*
@@ -371,25 +374,34 @@ ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
+	struct ps_data *ps;
 
 	/*
 	 * broadcast/multicast frame
 	 *
-	 * If any of the associated stations is in power save mode,
+	 * If any of the neighbor stations is in power save mode,
 	 * the frame is buffered to be sent after DTIM beacon frame.
 	 * This is done either by the hardware or us.
 	 */
 
-	/* powersaving STAs only in AP/VLAN mode */
-	if (!tx->sdata->bss)
+	/* powersaving STAs currently only in AP/VLAN mode */
+	if (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
+	    tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
+		if (!tx->sdata->bss)
+			return TX_CONTINUE;
+
+		ps = &tx->sdata->bss->ps;
+	} else {
 		return TX_CONTINUE;
+	}
+
 
 	/* no buffering for ordered frames */
 	if (ieee80211_has_order(hdr->frame_control))
 		return TX_CONTINUE;
 
 	/* no stations in PS mode */
-	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
+	if (!atomic_read(&ps->num_sta_ps))
 		return TX_CONTINUE;
 
 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
@@ -404,14 +416,14 @@ ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
 		purge_old_ps_buffers(tx->local);
 
-	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
+	if (skb_queue_len(&ps->bc_buf) >= AP_MAX_BC_BUFFER) {
 		ps_dbg(tx->sdata,
 		       "BC TX buffer full - dropping the oldest frame\n");
-		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
+		dev_kfree_skb(skb_dequeue(&ps->bc_buf));
 	} else
 		tx->local->total_ps_buffered++;
 
-	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
+	skb_queue_tail(&ps->bc_buf, tx->skb);
 
 	return TX_QUEUED;
 }
@@ -2209,9 +2221,8 @@ void ieee80211_tx_pending(unsigned long data)
 /* functions for drivers to get certain frames */
 
 static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
-				     struct ieee80211_if_ap *bss,
-				     struct sk_buff *skb,
-				     struct beacon_data *beacon)
+				     struct ps_data *ps,
+				     struct sk_buff *skb)
 {
 	u8 *pos, *tim;
 	int aid0 = 0;
@@ -2219,27 +2230,27 @@ static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 
 	/* Generate bitmap for TIM only if there are any STAs in power save
 	 * mode. */
-	if (atomic_read(&bss->num_sta_ps) > 0)
+	if (atomic_read(&ps->num_sta_ps) > 0)
 		/* in the hope that this is faster than
 		 * checking byte-for-byte */
-		have_bits = !bitmap_empty((unsigned long*)bss->tim,
+		have_bits = !bitmap_empty((unsigned long*)ps->tim,
 					  IEEE80211_MAX_AID+1);
 
-	if (bss->dtim_count == 0)
-		bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
+	if (ps->dtim_count == 0)
+		ps->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
 	else
-		bss->dtim_count--;
+		ps->dtim_count--;
 
 	tim = pos = (u8 *) skb_put(skb, 6);
 	*pos++ = WLAN_EID_TIM;
 	*pos++ = 4;
-	*pos++ = bss->dtim_count;
+	*pos++ = ps->dtim_count;
 	*pos++ = sdata->vif.bss_conf.dtim_period;
 
-	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
+	if (ps->dtim_count == 0 && !skb_queue_empty(&ps->bc_buf))
 		aid0 = 1;
 
-	bss->dtim_bc_mc = aid0 == 1;
+	ps->dtim_bc_mc = aid0 == 1;
 
 	if (have_bits) {
 		/* Find largest even number N1 so that bits numbered 1 through
@@ -2247,14 +2258,14 @@ static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 		 * (N2 + 1) x 8 through 2007 are 0. */
 		n1 = 0;
 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
-			if (bss->tim[i]) {
+			if (ps->tim[i]) {
 				n1 = i & 0xfe;
 				break;
 			}
 		}
 		n2 = n1;
 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
-			if (bss->tim[i]) {
+			if (ps->tim[i]) {
 				n2 = i;
 				break;
 			}
@@ -2264,7 +2275,7 @@ static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 		*pos++ = n1 | aid0;
 		/* Part Virt Bitmap */
 		skb_put(skb, n2 - n1);
-		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
+		memcpy(pos, ps->tim + n1, n2 - n1 + 1);
 
 		tim[1] = n2 - n1 + 4;
 	} else {
@@ -2281,8 +2292,6 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 	struct sk_buff *skb = NULL;
 	struct ieee80211_tx_info *info;
 	struct ieee80211_sub_if_data *sdata = NULL;
-	struct ieee80211_if_ap *ap = NULL;
-	struct beacon_data *beacon;
 	enum ieee80211_band band = local->oper_channel->band;
 	struct ieee80211_tx_rate_control txrc;
 
@@ -2299,8 +2308,9 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 		*tim_length = 0;
 
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
-		ap = &sdata->u.ap;
-		beacon = rcu_dereference(ap->beacon);
+		struct ieee80211_if_ap *ap = &sdata->u.ap;
+		struct beacon_data *beacon = rcu_dereference(ap->beacon);
+
 		if (beacon) {
 			/*
 			 * headroom, head length,
@@ -2324,14 +2334,12 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 			 * of the tim bitmap in mac80211 and the driver.
 			 */
 			if (local->tim_in_locked_section) {
-				ieee80211_beacon_add_tim(sdata, ap, skb,
-							 beacon);
+				ieee80211_beacon_add_tim(sdata, &ap->ps, skb);
 			} else {
 				unsigned long flags;
 
 				spin_lock_irqsave(&local->tim_lock, flags);
-				ieee80211_beacon_add_tim(sdata, ap, skb,
-							 beacon);
+				ieee80211_beacon_add_tim(sdata, &ap->ps, skb);
 				spin_unlock_irqrestore(&local->tim_lock, flags);
 			}
 
@@ -2651,29 +2659,37 @@ ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
 	struct sk_buff *skb = NULL;
 	struct ieee80211_tx_data tx;
 	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_if_ap *bss = NULL;
-	struct beacon_data *beacon;
+	struct ps_data *ps;
 	struct ieee80211_tx_info *info;
 
 	sdata = vif_to_sdata(vif);
-	bss = &sdata->u.ap;
 
 	rcu_read_lock();
-	beacon = rcu_dereference(bss->beacon);
 
-	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
+	if (sdata->vif.type == NL80211_IFTYPE_AP) {
+		struct beacon_data *beacon =
+				rcu_dereference(sdata->u.ap.beacon);
+
+		/* XXX is there any use for beacon here? */
+
+		if (!beacon || !beacon->head)
+			goto out;
+
+		ps = &sdata->u.ap.ps;
+	} else {
 		goto out;
+	}
 
-	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
+	if (ps->dtim_count != 0 || !ps->dtim_bc_mc)
 		goto out; /* send buffered bc/mc only after DTIM beacon */
 
 	while (1) {
-		skb = skb_dequeue(&bss->ps_bc_buf);
+		skb = skb_dequeue(&ps->bc_buf);
 		if (!skb)
 			goto out;
 		local->total_ps_buffered--;
 
-		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
+		if (!skb_queue_empty(&ps->bc_buf) && skb->len >= 2) {
 			struct ieee80211_hdr *hdr =
 				(struct ieee80211_hdr *) skb->data;
 			/* more buffered multicast/broadcast frames ==> set
-- 
1.7.9.5


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