r8169: remove the obsolete and incorrect AMD workaround
[~shefty/rdma-dev.git] / net / mac80211 / offchannel.c
1 /*
2  * Off-channel operation helpers
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2004, Instant802 Networks, Inc.
6  * Copyright 2005, Devicescape Software, Inc.
7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2009       Johannes Berg <johannes@sipsolutions.net>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 #include <linux/export.h>
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "driver-ops.h"
19
20 /*
21  * Tell our hardware to disable PS.
22  * Optionally inform AP that we will go to sleep so that it will buffer
23  * the frames while we are doing off-channel work.  This is optional
24  * because we *may* be doing work on-operating channel, and want our
25  * hardware unconditionally awake, but still let the AP send us normal frames.
26  */
27 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
28 {
29         struct ieee80211_local *local = sdata->local;
30         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
31
32         local->offchannel_ps_enabled = false;
33
34         /* FIXME: what to do when local->pspolling is true? */
35
36         del_timer_sync(&local->dynamic_ps_timer);
37         del_timer_sync(&ifmgd->bcn_mon_timer);
38         del_timer_sync(&ifmgd->conn_mon_timer);
39
40         cancel_work_sync(&local->dynamic_ps_enable_work);
41
42         if (local->hw.conf.flags & IEEE80211_CONF_PS) {
43                 local->offchannel_ps_enabled = true;
44                 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
45                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
46         }
47
48         if (!local->offchannel_ps_enabled ||
49             !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
50                 /*
51                  * If power save was enabled, no need to send a nullfunc
52                  * frame because AP knows that we are sleeping. But if the
53                  * hardware is creating the nullfunc frame for power save
54                  * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
55                  * enabled) and power save was enabled, the firmware just
56                  * sent a null frame with power save disabled. So we need
57                  * to send a new nullfunc frame to inform the AP that we
58                  * are again sleeping.
59                  */
60                 ieee80211_send_nullfunc(local, sdata, 1);
61 }
62
63 /* inform AP that we are awake again, unless power save is enabled */
64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
65 {
66         struct ieee80211_local *local = sdata->local;
67
68         if (!local->ps_sdata)
69                 ieee80211_send_nullfunc(local, sdata, 0);
70         else if (local->offchannel_ps_enabled) {
71                 /*
72                  * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
73                  * will send a nullfunc frame with the powersave bit set
74                  * even though the AP already knows that we are sleeping.
75                  * This could be avoided by sending a null frame with power
76                  * save bit disabled before enabling the power save, but
77                  * this doesn't gain anything.
78                  *
79                  * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
80                  * to send a nullfunc frame because AP already knows that
81                  * we are sleeping, let's just enable power save mode in
82                  * hardware.
83                  */
84                 /* TODO:  Only set hardware if CONF_PS changed?
85                  * TODO:  Should we set offchannel_ps_enabled to false?
86                  */
87                 local->hw.conf.flags |= IEEE80211_CONF_PS;
88                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
89         } else if (local->hw.conf.dynamic_ps_timeout > 0) {
90                 /*
91                  * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
92                  * had been running before leaving the operating channel,
93                  * restart the timer now and send a nullfunc frame to inform
94                  * the AP that we are awake.
95                  */
96                 ieee80211_send_nullfunc(local, sdata, 0);
97                 mod_timer(&local->dynamic_ps_timer, jiffies +
98                           msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
99         }
100
101         ieee80211_sta_reset_beacon_monitor(sdata);
102         ieee80211_sta_reset_conn_monitor(sdata);
103 }
104
105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
106                                     bool offchannel_ps_enable)
107 {
108         struct ieee80211_sub_if_data *sdata;
109
110         if (WARN_ON(local->use_chanctx))
111                 return;
112
113         /*
114          * notify the AP about us leaving the channel and stop all
115          * STA interfaces.
116          */
117         mutex_lock(&local->iflist_mtx);
118         list_for_each_entry(sdata, &local->interfaces, list) {
119                 if (!ieee80211_sdata_running(sdata))
120                         continue;
121
122                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
123                         continue;
124
125                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
126                         set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
127
128                 /* Check to see if we should disable beaconing. */
129                 if (sdata->vif.type == NL80211_IFTYPE_AP ||
130                     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
131                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
132                         ieee80211_bss_info_change_notify(
133                                 sdata, BSS_CHANGED_BEACON_ENABLED);
134
135                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
136                         netif_tx_stop_all_queues(sdata->dev);
137                         if (offchannel_ps_enable &&
138                             (sdata->vif.type == NL80211_IFTYPE_STATION) &&
139                             sdata->u.mgd.associated)
140                                 ieee80211_offchannel_ps_enable(sdata);
141                 }
142         }
143         mutex_unlock(&local->iflist_mtx);
144 }
145
146 void ieee80211_offchannel_return(struct ieee80211_local *local,
147                                  bool offchannel_ps_disable)
148 {
149         struct ieee80211_sub_if_data *sdata;
150
151         if (WARN_ON(local->use_chanctx))
152                 return;
153
154         mutex_lock(&local->iflist_mtx);
155         list_for_each_entry(sdata, &local->interfaces, list) {
156                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
157                         continue;
158
159                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
160                         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
161
162                 if (!ieee80211_sdata_running(sdata))
163                         continue;
164
165                 /* Tell AP we're back */
166                 if (offchannel_ps_disable &&
167                     sdata->vif.type == NL80211_IFTYPE_STATION) {
168                         if (sdata->u.mgd.associated)
169                                 ieee80211_offchannel_ps_disable(sdata);
170                 }
171
172                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
173                         /*
174                          * This may wake up queues even though the driver
175                          * currently has them stopped. This is not very
176                          * likely, since the driver won't have gotten any
177                          * (or hardly any) new packets while we weren't
178                          * on the right channel, and even if it happens
179                          * it will at most lead to queueing up one more
180                          * packet per queue in mac80211 rather than on
181                          * the interface qdisc.
182                          */
183                         netif_tx_wake_all_queues(sdata->dev);
184                 }
185
186                 if (sdata->vif.type == NL80211_IFTYPE_AP ||
187                     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
188                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
189                         ieee80211_bss_info_change_notify(
190                                 sdata, BSS_CHANGED_BEACON_ENABLED);
191         }
192         mutex_unlock(&local->iflist_mtx);
193 }
194
195 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
196 {
197         if (roc->notified)
198                 return;
199
200         if (roc->mgmt_tx_cookie) {
201                 if (!WARN_ON(!roc->frame)) {
202                         ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
203                                                   roc->chan->band);
204                         roc->frame = NULL;
205                 }
206         } else {
207                 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
208                                           roc->chan, roc->req_duration,
209                                           GFP_KERNEL);
210         }
211
212         roc->notified = true;
213 }
214
215 static void ieee80211_hw_roc_start(struct work_struct *work)
216 {
217         struct ieee80211_local *local =
218                 container_of(work, struct ieee80211_local, hw_roc_start);
219         struct ieee80211_roc_work *roc, *dep, *tmp;
220
221         mutex_lock(&local->mtx);
222
223         if (list_empty(&local->roc_list))
224                 goto out_unlock;
225
226         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
227                                list);
228
229         if (!roc->started)
230                 goto out_unlock;
231
232         roc->hw_begun = true;
233         roc->hw_start_time = local->hw_roc_start_time;
234
235         ieee80211_handle_roc_started(roc);
236         list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
237                 ieee80211_handle_roc_started(dep);
238
239                 if (dep->duration > roc->duration) {
240                         u32 dur = dep->duration;
241                         dep->duration = dur - roc->duration;
242                         roc->duration = dur;
243                         list_move(&dep->list, &roc->list);
244                 }
245         }
246  out_unlock:
247         mutex_unlock(&local->mtx);
248 }
249
250 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
251 {
252         struct ieee80211_local *local = hw_to_local(hw);
253
254         local->hw_roc_start_time = jiffies;
255
256         trace_api_ready_on_channel(local);
257
258         ieee80211_queue_work(hw, &local->hw_roc_start);
259 }
260 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
261
262 void ieee80211_start_next_roc(struct ieee80211_local *local)
263 {
264         struct ieee80211_roc_work *roc;
265
266         lockdep_assert_held(&local->mtx);
267
268         if (list_empty(&local->roc_list)) {
269                 ieee80211_run_deferred_scan(local);
270                 return;
271         }
272
273         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
274                                list);
275
276         if (WARN_ON_ONCE(roc->started))
277                 return;
278
279         if (local->ops->remain_on_channel) {
280                 int ret, duration = roc->duration;
281
282                 /* XXX: duplicated, see ieee80211_start_roc_work() */
283                 if (!duration)
284                         duration = 10;
285
286                 ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
287                                             duration);
288
289                 roc->started = true;
290
291                 if (ret) {
292                         wiphy_warn(local->hw.wiphy,
293                                    "failed to start next HW ROC (%d)\n", ret);
294                         /*
295                          * queue the work struct again to avoid recursion
296                          * when multiple failures occur
297                          */
298                         ieee80211_remain_on_channel_expired(&local->hw);
299                 }
300         } else {
301                 /* delay it a bit */
302                 ieee80211_queue_delayed_work(&local->hw, &roc->work,
303                                              round_jiffies_relative(HZ/2));
304         }
305 }
306
307 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
308 {
309         struct ieee80211_roc_work *dep, *tmp;
310
311         /* was never transmitted */
312         if (roc->frame) {
313                 cfg80211_mgmt_tx_status(&roc->sdata->wdev,
314                                         (unsigned long)roc->frame,
315                                         roc->frame->data, roc->frame->len,
316                                         false, GFP_KERNEL);
317                 kfree_skb(roc->frame);
318         }
319
320         if (!roc->mgmt_tx_cookie)
321                 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
322                                                    roc->cookie, roc->chan,
323                                                    GFP_KERNEL);
324
325         list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
326                 ieee80211_roc_notify_destroy(dep);
327
328         kfree(roc);
329 }
330
331 void ieee80211_sw_roc_work(struct work_struct *work)
332 {
333         struct ieee80211_roc_work *roc =
334                 container_of(work, struct ieee80211_roc_work, work.work);
335         struct ieee80211_sub_if_data *sdata = roc->sdata;
336         struct ieee80211_local *local = sdata->local;
337         bool started;
338
339         mutex_lock(&local->mtx);
340
341         if (roc->abort)
342                 goto finish;
343
344         if (WARN_ON(list_empty(&local->roc_list)))
345                 goto out_unlock;
346
347         if (WARN_ON(roc != list_first_entry(&local->roc_list,
348                                             struct ieee80211_roc_work,
349                                             list)))
350                 goto out_unlock;
351
352         if (!roc->started) {
353                 struct ieee80211_roc_work *dep;
354
355                 /* start this ROC */
356
357                 /* switch channel etc */
358                 ieee80211_recalc_idle(local);
359
360                 local->tmp_channel = roc->chan;
361                 ieee80211_hw_config(local, 0);
362
363                 /* tell userspace or send frame */
364                 ieee80211_handle_roc_started(roc);
365                 list_for_each_entry(dep, &roc->dependents, list)
366                         ieee80211_handle_roc_started(dep);
367
368                 /* if it was pure TX, just finish right away */
369                 if (!roc->duration)
370                         goto finish;
371
372                 roc->started = true;
373                 ieee80211_queue_delayed_work(&local->hw, &roc->work,
374                                              msecs_to_jiffies(roc->duration));
375         } else {
376                 /* finish this ROC */
377  finish:
378                 list_del(&roc->list);
379                 started = roc->started;
380                 ieee80211_roc_notify_destroy(roc);
381
382                 if (started) {
383                         drv_flush(local, false);
384
385                         local->tmp_channel = NULL;
386                         ieee80211_hw_config(local, 0);
387
388                         ieee80211_offchannel_return(local, true);
389                 }
390
391                 ieee80211_recalc_idle(local);
392
393                 if (started)
394                         ieee80211_start_next_roc(local);
395         }
396
397  out_unlock:
398         mutex_unlock(&local->mtx);
399 }
400
401 static void ieee80211_hw_roc_done(struct work_struct *work)
402 {
403         struct ieee80211_local *local =
404                 container_of(work, struct ieee80211_local, hw_roc_done);
405         struct ieee80211_roc_work *roc;
406
407         mutex_lock(&local->mtx);
408
409         if (list_empty(&local->roc_list))
410                 goto out_unlock;
411
412         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
413                                list);
414
415         if (!roc->started)
416                 goto out_unlock;
417
418         list_del(&roc->list);
419
420         ieee80211_roc_notify_destroy(roc);
421
422         /* if there's another roc, start it now */
423         ieee80211_start_next_roc(local);
424
425  out_unlock:
426         mutex_unlock(&local->mtx);
427 }
428
429 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
430 {
431         struct ieee80211_local *local = hw_to_local(hw);
432
433         trace_api_remain_on_channel_expired(local);
434
435         ieee80211_queue_work(hw, &local->hw_roc_done);
436 }
437 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
438
439 void ieee80211_roc_setup(struct ieee80211_local *local)
440 {
441         INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
442         INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
443         INIT_LIST_HEAD(&local->roc_list);
444 }
445
446 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
447 {
448         struct ieee80211_local *local = sdata->local;
449         struct ieee80211_roc_work *roc, *tmp;
450         LIST_HEAD(tmp_list);
451
452         mutex_lock(&local->mtx);
453         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
454                 if (roc->sdata != sdata)
455                         continue;
456
457                 if (roc->started && local->ops->remain_on_channel) {
458                         /* can race, so ignore return value */
459                         drv_cancel_remain_on_channel(local);
460                 }
461
462                 list_move_tail(&roc->list, &tmp_list);
463                 roc->abort = true;
464         }
465         mutex_unlock(&local->mtx);
466
467         list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
468                 if (local->ops->remain_on_channel) {
469                         list_del(&roc->list);
470                         ieee80211_roc_notify_destroy(roc);
471                 } else {
472                         ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
473
474                         /* work will clean up etc */
475                         flush_delayed_work(&roc->work);
476                 }
477         }
478
479         WARN_ON_ONCE(!list_empty(&tmp_list));
480 }