cregit-Linux how code gets into the kernel

Release 4.8 net/mac80211/offchannel.c

Directory: net/mac80211
/*
 * Off-channel operation helpers
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.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/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"

/*
 * Tell our hardware to disable PS.
 * Optionally inform AP that we will go to sleep so that it will buffer
 * the frames while we are doing off-channel work.  This is optional
 * because we *may* be doing work on-operating channel, and want our
 * hardware unconditionally awake, but still let the AP send us normal frames.
 */

static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; local->offchannel_ps_enabled = false; /* FIXME: what to do when local->pspolling is true? */ del_timer_sync(&local->dynamic_ps_timer); del_timer_sync(&ifmgd->bcn_mon_timer); del_timer_sync(&ifmgd->conn_mon_timer); cancel_work_sync(&local->dynamic_ps_enable_work); if (local->hw.conf.flags & IEEE80211_CONF_PS) { local->offchannel_ps_enabled = true; local->hw.conf.flags &= ~IEEE80211_CONF_PS; ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } if (!local->offchannel_ps_enabled || !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK)) /* * If power save was enabled, no need to send a nullfunc * frame because AP knows that we are sleeping. But if the * hardware is creating the nullfunc frame for power save * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not * enabled) and power save was enabled, the firmware just * sent a null frame with power save disabled. So we need * to send a new nullfunc frame to inform the AP that we * are again sleeping. */ ieee80211_send_nullfunc(local, sdata, true); }

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jouni malinenjouni malinen10173.72%116.67%
luis r. rodriguezluis r. rodriguez2820.44%233.33%
johannes bergjohannes berg75.11%233.33%
ben greearben greear10.73%116.67%
Total137100.00%6100.00%

/* inform AP that we are awake again, unless power save is enabled */
static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; if (!local->ps_sdata) ieee80211_send_nullfunc(local, sdata, false); else if (local->offchannel_ps_enabled) { /* * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware * will send a nullfunc frame with the powersave bit set * even though the AP already knows that we are sleeping. * This could be avoided by sending a null frame with power * save bit disabled before enabling the power save, but * this doesn't gain anything. * * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need * to send a nullfunc frame because AP already knows that * we are sleeping, let's just enable power save mode in * hardware. */ /* TODO: Only set hardware if CONF_PS changed? * TODO: Should we set offchannel_ps_enabled to false? */ local->hw.conf.flags |= IEEE80211_CONF_PS; ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } else if (local->hw.conf.dynamic_ps_timeout > 0) { /* * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer * had been running before leaving the operating channel, * restart the timer now and send a nullfunc frame to inform * the AP that we are awake. */ ieee80211_send_nullfunc(local, sdata, false); mod_timer(&local->dynamic_ps_timer, jiffies + msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); } ieee80211_sta_reset_beacon_monitor(sdata); ieee80211_sta_reset_conn_monitor(sdata); }

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jouni malinenjouni malinen10789.17%120.00%
luis r. rodriguezluis r. rodriguez108.33%240.00%
johannes bergjohannes berg21.67%120.00%
ben greearben greear10.83%120.00%
Total120100.00%5100.00%


void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; if (WARN_ON(local->use_chanctx)) return; /* * notify the AP about us leaving the channel and stop all * STA interfaces. */ /* * Stop queues and transmit all frames queued by the driver * before sending nullfunc to enable powersave at the AP. */ ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, false); ieee80211_flush_queues(local, NULL, false); mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) continue; if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) continue; if (sdata->vif.type != NL80211_IFTYPE_MONITOR) set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); /* Check to see if we should disable beaconing. */ if (sdata->vif.bss_conf.enable_beacon) { set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); sdata->vif.bss_conf.enable_beacon = false; ieee80211_bss_info_change_notify( sdata, BSS_CHANGED_BEACON_ENABLED); } if (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.associated) ieee80211_offchannel_ps_enable(sdata); } mutex_unlock(&local->iflist_mtx); }

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jouni malinenjouni malinen7743.02%19.09%
johannes bergjohannes berg4525.14%545.45%
ben greearben greear3720.67%19.09%
seth forsheeseth forshee168.94%218.18%
luciano coelholuciano coelho21.12%19.09%
emmanuel grumbachemmanuel grumbach21.12%19.09%
Total179100.00%11100.00%


void ieee80211_offchannel_return(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; if (WARN_ON(local->use_chanctx)) return; mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) continue; if (sdata->vif.type != NL80211_IFTYPE_MONITOR) clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); if (!ieee80211_sdata_running(sdata)) continue; /* Tell AP we're back */ if (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.associated) ieee80211_offchannel_ps_disable(sdata); if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state)) { sdata->vif.bss_conf.enable_beacon = true; ieee80211_bss_info_change_notify( sdata, BSS_CHANGED_BEACON_ENABLED); } } mutex_unlock(&local->iflist_mtx); ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, false); }

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jouni malinenjouni malinen8754.38%110.00%
johannes bergjohannes berg3823.75%440.00%
eliad pellereliad peller2012.50%110.00%
seth forsheeseth forshee106.25%110.00%
benoit papillaultbenoit papillault21.25%110.00%
luciano coelholuciano coelho21.25%110.00%
stanislaw gruszkastanislaw gruszka10.62%110.00%
Total160100.00%10100.00%


static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc) { /* was never transmitted */ if (roc->frame) { cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie, roc->frame->data, roc->frame->len, false, GFP_KERNEL); ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame); } if (!roc->mgmt_tx_cookie) cfg80211_remain_on_channel_expired(&roc->sdata->wdev, roc->cookie, roc->chan, GFP_KERNEL); list_del(&roc->list); kfree(roc); }

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static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local, unsigned long now) { struct ieee80211_roc_work *roc, *tmp; long remaining_dur_min = LONG_MAX; lockdep_assert_held(&local->mtx); list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { long remaining; if (!roc->started) break; remaining = roc->start_time + msecs_to_jiffies(roc->duration) - now; /* In case of HW ROC, it is possible that the HW finished the * ROC session before the actual requested time. In such a case * end the ROC session (disregarding the remaining time). */ if (roc->abort || roc->hw_begun || remaining <= 0) ieee80211_roc_notify_destroy(roc); else remaining_dur_min = min(remaining_dur_min, remaining); } return remaining_dur_min; }

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static bool ieee80211_recalc_sw_work(struct ieee80211_local *local, unsigned long now) { long dur = ieee80211_end_finished_rocs(local, now); if (dur == LONG_MAX) return false; mod_delayed_work(local->workqueue, &local->roc_work, dur); return true; }

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static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc, unsigned long start_time) { if (WARN_ON(roc->notified)) return; roc->start_time = start_time; roc->started = true; if (roc->mgmt_tx_cookie) { if (!WARN_ON(!roc->frame)) { ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7, roc->chan->band); roc->frame = NULL; } } else { cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie, roc->chan, roc->req_duration, GFP_KERNEL); } roc->notified = true; }

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ilan peerilan peer32.59%114.29%
Total116100.00%7100.00%


static void ieee80211_hw_roc_start(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_start); struct ieee80211_roc_work *roc; mutex_lock(&local->mtx); list_for_each_entry(roc, &local->roc_list, list) { if (!roc->started) break; roc->hw_begun = true; ieee80211_handle_roc_started(roc, local->hw_roc_start_time); } mutex_unlock(&local->mtx); }

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void ieee80211_ready_on_channel(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); local->hw_roc_start_time = jiffies; trace_api_ready_on_channel(local); ieee80211_queue_work(hw, &local->hw_roc_start); }

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EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
static void _ieee80211_start_next_roc(struct ieee80211_local *local) { struct ieee80211_roc_work *roc, *tmp; enum ieee80211_roc_type type; u32 min_dur, max_dur; lockdep_assert_held(&local->mtx); if (WARN_ON(list_empty(&local->roc_list))) return; roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, list); if (WARN_ON(roc->started)) return; min_dur = roc->duration; max_dur = roc->duration; type = roc->type; list_for_each_entry(tmp, &local->roc_list, list) { if (tmp == roc) continue; if (tmp->sdata != roc->sdata || tmp->chan != roc->chan) break; max_dur = max(tmp->duration, max_dur); min_dur = min(tmp->duration, min_dur); type = max(tmp->type, type); } if (local->ops->remain_on_channel) { int ret = drv_remain_on_channel(local, roc->sdata, roc->chan, max_dur, type); if (ret) { wiphy_warn(local->hw.wiphy, "failed to start next HW ROC (%d)\n", ret); /* * queue the work struct again to avoid recursion * when multiple failures occur */ list_for_each_entry(tmp, &local->roc_list, list) { if (tmp->sdata != roc->sdata || tmp->chan != roc->chan) break; tmp->started = true; tmp->abort = true; } ieee80211_queue_work(&local->hw, &local->hw_roc_done); return; } /* we'll notify about the start once the HW calls back */ list_for_each_entry(tmp, &local->roc_list, list) { if (tmp->sdata != roc->sdata || tmp->chan != roc->chan) break; tmp->started = true; } } else { /* If actually operating on the desired channel (with at least * 20 MHz channel width) don't stop all the operations but still * treat it as though the ROC operation started properly, so * other ROC operations won't interfere with this one. */ roc->on_channel = roc->chan == local->_oper_chandef.chan && local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 && local->_oper_chandef.width != NL80211_CHAN_WIDTH_10; /* start this ROC */ ieee80211_recalc_idle(local); if (!roc->on_channel) { ieee80211_offchannel_stop_vifs(local); local->tmp_channel = roc->chan; ieee80211_hw_config(local, 0); } ieee80211_queue_delayed_work(&local->hw, &local->roc_work, msecs_to_jiffies(min_dur)); /* tell userspace or send frame(s) */ list_for_each_entry(tmp, &local->roc_list, list) { if (tmp->sdata != roc->sdata || tmp->chan != roc->chan) break; tmp->on_channel = roc->on_channel; ieee80211_handle_roc_started(tmp, jiffies); } } }

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void ieee80211_start_next_roc(struct ieee80211_local *local) { struct ieee80211_roc_work *roc; lockdep_assert_held(&local->mtx); if (list_empty(&local->roc_list)) { ieee80211_run_deferred_scan(local); return; } /* defer roc if driver is not started (i.e. during reconfig) */ if (local->in_reconfig) return; roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, list); if (WARN_ON_ONCE(roc->started)) return; if (local->ops->remain_on_channel) { _ieee80211_start_next_roc(local); } else { /* delay it a bit */ ieee80211_queue_delayed_work(&local->hw, &local->roc_work, round_jiffies_relative(HZ/2)); } }

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johannes bergjohannes berg10492.04%571.43%
eliad pellereliad peller87.08%114.29%
alan coxalan cox10.88%114.29%
Total113100.00%7100.00%


static void __ieee80211_roc_work(struct ieee80211_local *local) { struct ieee80211_roc_work *roc; bool on_channel; lockdep_assert_held(&local->mtx); if (WARN_ON(local->ops->remain_on_channel)) return; roc = list_first_entry_or_null(&local->roc_list, struct ieee80211_roc_work, list); if (!roc) return; if (!roc->started) { WARN_ON(local->use_chanctx); _ieee80211_start_next_roc(local); } else { on_channel = roc->on_channel; if (ieee80211_recalc_sw_work(local, jiffies)) return; /* careful - roc pointer became invalid during recalc */ if (!on_channel) { ieee80211_flush_queues(local, NULL, false); local->tmp_channel = NULL; ieee80211_hw_config(local, 0); ieee80211_offchannel_return(local); } ieee80211_recalc_idle(local); ieee80211_start_next_roc(local); } }

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emmanuel grumbachemmanuel grumbach21.38%116.67%
Total145100.00%6100.00%


static void ieee80211_roc_work(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, roc_work.work); mutex_lock(&local->mtx); __ieee80211_roc_work(local); mutex_unlock(&local->mtx); }

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jouni malinenjouni malinen918.37%133.33%
Total49100.00%3100.00%


static void ieee80211_hw_roc_done(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_done); mutex_lock(&local->mtx); ieee80211_end_finished_rocs(local, jiffies); /* if there's another roc, start it now */ ieee80211_start_next_roc(local); mutex_unlock(&local->mtx); }

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void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); trace_api_remain_on_channel_expired(local); ieee80211_queue_work(hw, &local->hw_roc_done); }

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EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
static bool ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local, struct ieee80211_roc_work *new_roc, struct ieee80211_roc_work *cur_roc) { unsigned long now = jiffies; unsigned long remaining; if (WARN_ON(!cur_roc->started)) return false; /* if it was scheduled in the hardware, but not started yet, * we can only combine if the older one had a longer duration */ if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration) return false; remaining = cur_roc->start_time + msecs_to_jiffies(cur_roc->duration) - now; /* if it doesn't fit entirely, schedule a new one */ if (new_roc->duration > jiffies_to_msecs(remaining)) return false; /* add just after the current one so we combine their finish later */ list_add(&new_roc->list, &cur_roc->list); /* if the existing one has already begun then let this one also * begin, otherwise they'll both be marked properly by the work * struct that runs once the driver notifies us of the beginning */ if (cur_roc->hw_begun) { new_roc->hw_begun = true; ieee80211_handle_roc_started(new_roc, now); } return true; }

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static int ieee80211_start_roc_work(struct ieee80211_local *local, struct ieee80211_sub_if_data *sdata, struct ieee80211_channel *channel, unsigned int duration, u64 *cookie, struct sk_buff *txskb, enum ieee80211_roc_type type) { struct ieee80211_roc_work *roc, *tmp; bool queued = false, combine_started = true; int ret; lockdep_assert_held(&local->mtx); if (local->use_chanctx && !local->ops->remain_on_channel) return -EOPNOTSUPP; roc = kzalloc(sizeof(*roc), GFP_KERNEL); if (!roc) return -ENOMEM; /* * If the duration is zero, then the driver * wouldn't actually do anything. Set it to * 10 for now. * * TODO: cancel the off-channel operation * when we get the SKB's TX status and * the wait time was zero before. */ if (!duration) duration = 10; roc->chan = channel; roc->duration = duration; roc->req_duration = duration; roc->frame = txskb; roc->type = type; roc->sdata = sdata; /* * cookie is either the roc cookie (for normal roc) * or the SKB (for mgmt TX) */ if (!txskb) { roc->cookie = ieee80211_mgmt_tx_cookie(local); *cookie = roc->cookie; } else { roc->mgmt_tx_cookie = *cookie; } /* if there's no need to queue, handle it immediately */ if (list_empty(&local->roc_list) && !local->scanning && !ieee80211_is_radar_required(local)) { /* if not HW assist, just queue & schedule work */ if (!local->ops->remain_on_channel) { list_add_tail(&roc->list, &local->roc_list); ieee80211_queue_delayed_work(&local->hw, &local->roc_work, 0); } else { /* otherwise actually kick it off here * (for error handling) */ ret = drv_remain_on_channel(local, sdata, channel, duration, type); if (ret) { kfree(roc); return ret; } roc->started = true; list_add_tail(&roc->list, &local->roc_list); } return 0; } /* otherwise handle queueing */ list_for_each_entry(tmp, &local->roc_list, list) { if (tmp->chan != channel || tmp->sdata != sdata) continue; /* * Extend this ROC if possible: If it hasn't started, add * just after the new one to combine. */ if (!tmp->started) { list_add(&roc->list, &tmp->list); queued = true; break; } if (!combine_started) continue; if (!local->ops->remain_on_channel) { /* If there's no hardware remain-on-channel, and * doing so won't push us over the maximum r-o-c * we allow, then we can just add the new one to * the list and mark it as having started now. * If it would push over the limit, don't try to * combine with other started ones (that haven't * been running as long) but potentially sort it * with others that had the same fate. */ unsigned long now = jiffies; u32 elapsed = jiffies_to_msecs(now - tmp->start_time); struct wiphy *wiphy = local->hw.wiphy; u32 max_roc = wiphy->max_remain_on_channel_duration; if (elapsed + roc->duration > max_roc) { combine_started = false; continue; } list_add(&roc->list, &tmp->list); queued = true; roc->on_channel = tmp->on_channel; ieee80211_handle_roc_started(roc, now); ieee80211_recalc_sw_work(local, now); break; } queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp); if (queued) break; /* if it wasn't queued, perhaps it can be combined with * another that also couldn't get combined previously, * but no need to check for already started ones, since * that can't work. */ combine_started = false; } if (!queued) list_add_tail(&roc->list, &local->roc_list); return 0; }

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int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev, struct ieee80211_channel *chan, unsigned int duration, u64 *cookie) { struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev); struct ieee80211_local *local = sdata->local; int ret; mutex_lock(&local->mtx); ret = ieee80211_start_roc_work(local, sdata, chan, duration, cookie, NULL, IEEE80211_ROC_TYPE_NORMAL); mutex_unlock(&local->mtx); return ret; }

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static int ieee80211_cancel_roc(struct ieee80211_local *local, u64 cookie, bool mgmt_tx) { struct ieee80211_roc_work *roc, *tmp, *found = NULL; int ret; if (!cookie) return -ENOENT; mutex_lock(&local->mtx); list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { if (!mgmt_tx && roc->cookie != cookie) continue; else if (mgmt_tx && roc->mgmt_tx_cookie != cookie) continue; found = roc; break; } if (!found) { mutex_unlock(&local->mtx); return -ENOENT; } if (!found->started) { ieee80211_roc_notify_destroy(found); goto out_unlock; } if (local->ops->remain_on_channel) { ret = drv_cancel_remain_on_channel(local); if (WARN_ON_ONCE(ret)) { mutex_unlock(&local->mtx); return ret; } /* TODO: * if multiple items were combined here then we really shouldn't * cancel them all - we should wait for as much time as needed * for the longest remaining one, and only then cancel ... */ list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { if (!roc->started) break; if (roc == found) found = NULL; ieee80211_roc_notify_destroy(roc); } /* that really must not happen - it was started */ WARN_ON(found);