1 files changed, 373 insertions, 0 deletions

diff --git a/net/mac80211/work.c b/net/mac80211/work.c
new file mode 100644
index 00000000..c6e230ef
--- /dev/null
+++ b/net/mac80211/work.c
@@ -0,0 +1,373 @@
+/*
+ * mac80211 work implementation
+ *
+ * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
+ * Copyright 2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/etherdevice.h>
+#include <linux/crc32.h>
+#include <linux/slab.h>
+#include <net/mac80211.h>
+#include <asm/unaligned.h>
+
+#include "ieee80211_i.h"
+#include "rate.h"
+#include "driver-ops.h"
+
+enum work_action {
+	WORK_ACT_NONE,
+	WORK_ACT_TIMEOUT,
+};
+
+
+/* utils */
+static inline void ASSERT_WORK_MTX(struct ieee80211_local *local)
+{
+	lockdep_assert_held(&local->mtx);
+}
+
+/*
+ * We can have multiple work items (and connection probing)
+ * scheduling this timer, but we need to take care to only
+ * reschedule it when it should fire _earlier_ than it was
+ * asked for before, or if it's not pending right now. This
+ * function ensures that. Note that it then is required to
+ * run this function for all timeouts after the first one
+ * has happened -- the work that runs from this timer will
+ * do that.
+ */
+static void run_again(struct ieee80211_local *local,
+		      unsigned long timeout)
+{
+	ASSERT_WORK_MTX(local);
+
+	if (!timer_pending(&local->work_timer) ||
+	    time_before(timeout, local->work_timer.expires))
+		mod_timer(&local->work_timer, timeout);
+}
+
+void free_work(struct ieee80211_work *wk)
+{
+	kfree_rcu(wk, rcu_head);
+}
+
+static enum work_action __must_check
+ieee80211_remain_on_channel_timeout(struct ieee80211_work *wk)
+{
+	/*
+	 * First time we run, do nothing -- the generic code will
+	 * have switched to the right channel etc.
+	 */
+	if (!wk->started) {
+		wk->timeout = jiffies + msecs_to_jiffies(wk->remain.duration);
+
+		cfg80211_ready_on_channel(wk->sdata->dev, (unsigned long) wk,
+					  wk->chan, wk->chan_type,
+					  wk->remain.duration, GFP_KERNEL);
+
+		return WORK_ACT_NONE;
+	}
+
+	return WORK_ACT_TIMEOUT;
+}
+
+static enum work_action __must_check
+ieee80211_offchannel_tx(struct ieee80211_work *wk)
+{
+	if (!wk->started) {
+		wk->timeout = jiffies + msecs_to_jiffies(wk->offchan_tx.wait);
+
+		/*
+		 * After this, offchan_tx.frame remains but now is no
+		 * longer a valid pointer -- we still need it as the
+		 * cookie for canceling this work/status matching.
+		 */
+		ieee80211_tx_skb(wk->sdata, wk->offchan_tx.frame);
+
+		return WORK_ACT_NONE;
+	}
+
+	return WORK_ACT_TIMEOUT;
+}
+
+static void ieee80211_work_timer(unsigned long data)
+{
+	struct ieee80211_local *local = (void *) data;
+
+	if (local->quiescing)
+		return;
+
+	ieee80211_queue_work(&local->hw, &local->work_work);
+}
+
+static void ieee80211_work_work(struct work_struct *work)
+{
+	struct ieee80211_local *local =
+		container_of(work, struct ieee80211_local, work_work);
+	struct ieee80211_work *wk, *tmp;
+	LIST_HEAD(free_work);
+	enum work_action rma;
+	bool remain_off_channel = false;
+
+	if (local->scanning)
+		return;
+
+	/*
+	 * ieee80211_queue_work() should have picked up most cases,
+	 * here we'll pick the rest.
+	 */
+	if (WARN(local->suspended, "work scheduled while going to suspend\n"))
+		return;
+
+	mutex_lock(&local->mtx);
+
+	ieee80211_recalc_idle(local);
+
+	list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+		bool started = wk->started;
+
+		/* mark work as started if it's on the current off-channel */
+		if (!started && local->tmp_channel &&
+		    wk->chan == local->tmp_channel &&
+		    wk->chan_type == local->tmp_channel_type) {
+			started = true;
+			wk->timeout = jiffies;
+		}
+
+		if (!started && !local->tmp_channel) {
+			ieee80211_offchannel_stop_vifs(local, true);
+
+			local->tmp_channel = wk->chan;
+			local->tmp_channel_type = wk->chan_type;
+
+			ieee80211_hw_config(local, 0);
+
+			started = true;
+			wk->timeout = jiffies;
+		}
+
+		/* don't try to work with items that aren't started */
+		if (!started)
+			continue;
+
+		if (time_is_after_jiffies(wk->timeout)) {
+			/*
+			 * This work item isn't supposed to be worked on
+			 * right now, but take care to adjust the timer
+			 * properly.
+			 */
+			run_again(local, wk->timeout);
+			continue;
+		}
+
+		switch (wk->type) {
+		default:
+			WARN_ON(1);
+			/* nothing */
+			rma = WORK_ACT_NONE;
+			break;
+		case IEEE80211_WORK_ABORT:
+			rma = WORK_ACT_TIMEOUT;
+			break;
+		case IEEE80211_WORK_REMAIN_ON_CHANNEL:
+			rma = ieee80211_remain_on_channel_timeout(wk);
+			break;
+		case IEEE80211_WORK_OFFCHANNEL_TX:
+			rma = ieee80211_offchannel_tx(wk);
+			break;
+		}
+
+		wk->started = started;
+
+		switch (rma) {
+		case WORK_ACT_NONE:
+			/* might have changed the timeout */
+			run_again(local, wk->timeout);
+			break;
+		case WORK_ACT_TIMEOUT:
+			list_del_rcu(&wk->list);
+			synchronize_rcu();
+			list_add(&wk->list, &free_work);
+			break;
+		default:
+			WARN(1, "unexpected: %d", rma);
+		}
+	}
+
+	list_for_each_entry(wk, &local->work_list, list) {
+		if (!wk->started)
+			continue;
+		if (wk->chan != local->tmp_channel ||
+		    wk->chan_type != local->tmp_channel_type)
+			continue;
+		remain_off_channel = true;
+	}
+
+	if (!remain_off_channel && local->tmp_channel) {
+		local->tmp_channel = NULL;
+		ieee80211_hw_config(local, 0);
+
+		ieee80211_offchannel_return(local, true);
+
+		/* give connection some time to breathe */
+		run_again(local, jiffies + HZ/2);
+	}
+
+	if (list_empty(&local->work_list) && local->scan_req &&
+	    !local->scanning)
+		ieee80211_queue_delayed_work(&local->hw,
+					     &local->scan_work,
+					     round_jiffies_relative(0));
+
+	ieee80211_recalc_idle(local);
+
+	mutex_unlock(&local->mtx);
+
+	list_for_each_entry_safe(wk, tmp, &free_work, list) {
+		wk->done(wk, NULL);
+		list_del(&wk->list);
+		kfree(wk);
+	}
+}
+
+void ieee80211_add_work(struct ieee80211_work *wk)
+{
+	struct ieee80211_local *local;
+
+	if (WARN_ON(!wk->chan))
+		return;
+
+	if (WARN_ON(!wk->sdata))
+		return;
+
+	if (WARN_ON(!wk->done))
+		return;
+
+	if (WARN_ON(!ieee80211_sdata_running(wk->sdata)))
+		return;
+
+	wk->started = false;
+
+	local = wk->sdata->local;
+	mutex_lock(&local->mtx);
+	list_add_tail(&wk->list, &local->work_list);
+	mutex_unlock(&local->mtx);
+
+	ieee80211_queue_work(&local->hw, &local->work_work);
+}
+
+void ieee80211_work_init(struct ieee80211_local *local)
+{
+	INIT_LIST_HEAD(&local->work_list);
+	setup_timer(&local->work_timer, ieee80211_work_timer,
+		    (unsigned long)local);
+	INIT_WORK(&local->work_work, ieee80211_work_work);
+}
+
+void ieee80211_work_purge(struct ieee80211_sub_if_data *sdata)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_work *wk;
+	bool cleanup = false;
+
+	mutex_lock(&local->mtx);
+	list_for_each_entry(wk, &local->work_list, list) {
+		if (wk->sdata != sdata)
+			continue;
+		cleanup = true;
+		wk->type = IEEE80211_WORK_ABORT;
+		wk->started = true;
+		wk->timeout = jiffies;
+	}
+	mutex_unlock(&local->mtx);
+
+	/* run cleanups etc. */
+	if (cleanup)
+		ieee80211_work_work(&local->work_work);
+
+	mutex_lock(&local->mtx);
+	list_for_each_entry(wk, &local->work_list, list) {
+		if (wk->sdata != sdata)
+			continue;
+		WARN_ON(1);
+		break;
+	}
+	mutex_unlock(&local->mtx);
+}
+
+static enum work_done_result ieee80211_remain_done(struct ieee80211_work *wk,
+						   struct sk_buff *skb)
+{
+	/*
+	 * We are done serving the remain-on-channel command.
+	 */
+	cfg80211_remain_on_channel_expired(wk->sdata->dev, (unsigned long) wk,
+					   wk->chan, wk->chan_type,
+					   GFP_KERNEL);
+
+	return WORK_DONE_DESTROY;
+}
+
+int ieee80211_wk_remain_on_channel(struct ieee80211_sub_if_data *sdata,
+				   struct ieee80211_channel *chan,
+				   enum nl80211_channel_type channel_type,
+				   unsigned int duration, u64 *cookie)
+{
+	struct ieee80211_work *wk;
+
+	wk = kzalloc(sizeof(*wk), GFP_KERNEL);
+	if (!wk)
+		return -ENOMEM;
+
+	wk->type = IEEE80211_WORK_REMAIN_ON_CHANNEL;
+	wk->chan = chan;
+	wk->chan_type = channel_type;
+	wk->sdata = sdata;
+	wk->done = ieee80211_remain_done;
+
+	wk->remain.duration = duration;
+
+	*cookie = (unsigned long) wk;
+
+	ieee80211_add_work(wk);
+
+	return 0;
+}
+
+int ieee80211_wk_cancel_remain_on_channel(struct ieee80211_sub_if_data *sdata,
+					  u64 cookie)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_work *wk, *tmp;
+	bool found = false;
+
+	mutex_lock(&local->mtx);
+	list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+		if ((unsigned long) wk == cookie) {
+			wk->timeout = jiffies;
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&local->mtx);
+
+	if (!found)
+		return -ENOENT;
+
+	ieee80211_queue_work(&local->hw, &local->work_work);
+
+	return 0;
+}