diff options
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/channel.c')
-rw-r--r-- | drivers/net/wireless/ath/ath9k/channel.c | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c new file mode 100644 index 000000000000..ba214ebdcd16 --- /dev/null +++ b/drivers/net/wireless/ath/ath9k/channel.c @@ -0,0 +1,685 @@ +/* + * Copyright (c) 2014 Qualcomm Atheros, Inc. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "ath9k.h" + +/* Set/change channels. If the channel is really being changed, it's done + * by reseting the chip. To accomplish this we must first cleanup any pending + * DMA, then restart stuff. + */ +static int ath_set_channel(struct ath_softc *sc) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ieee80211_hw *hw = sc->hw; + struct ath9k_channel *hchan; + struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef; + struct ieee80211_channel *chan = chandef->chan; + int pos = chan->hw_value; + int old_pos = -1; + int r; + + if (test_bit(ATH_OP_INVALID, &common->op_flags)) + return -EIO; + + if (ah->curchan) + old_pos = ah->curchan - &ah->channels[0]; + + ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n", + chan->center_freq, chandef->width); + + /* update survey stats for the old channel before switching */ + spin_lock_bh(&common->cc_lock); + ath_update_survey_stats(sc); + spin_unlock_bh(&common->cc_lock); + + ath9k_cmn_get_channel(hw, ah, chandef); + + /* If the operating channel changes, change the survey in-use flags + * along with it. + * Reset the survey data for the new channel, unless we're switching + * back to the operating channel from an off-channel operation. + */ + if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) { + if (sc->cur_survey) + sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE; + + sc->cur_survey = &sc->survey[pos]; + + memset(sc->cur_survey, 0, sizeof(struct survey_info)); + sc->cur_survey->filled |= SURVEY_INFO_IN_USE; + } else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) { + memset(&sc->survey[pos], 0, sizeof(struct survey_info)); + } + + hchan = &sc->sc_ah->channels[pos]; + r = ath_reset_internal(sc, hchan); + if (r) + return r; + + /* The most recent snapshot of channel->noisefloor for the old + * channel is only available after the hardware reset. Copy it to + * the survey stats now. + */ + if (old_pos >= 0) + ath_update_survey_nf(sc, old_pos); + + /* Enable radar pulse detection if on a DFS channel. Spectral + * scanning and radar detection can not be used concurrently. + */ + if (hw->conf.radar_enabled) { + u32 rxfilter; + + /* set HW specific DFS configuration */ + ath9k_hw_set_radar_params(ah); + rxfilter = ath9k_hw_getrxfilter(ah); + rxfilter |= ATH9K_RX_FILTER_PHYRADAR | + ATH9K_RX_FILTER_PHYERR; + ath9k_hw_setrxfilter(ah, rxfilter); + ath_dbg(common, DFS, "DFS enabled at freq %d\n", + chan->center_freq); + } else { + /* perform spectral scan if requested. */ + if (test_bit(ATH_OP_SCANNING, &common->op_flags) && + sc->spectral_mode == SPECTRAL_CHANSCAN) + ath9k_spectral_scan_trigger(hw); + } + + return 0; +} + +static bool +ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp, + bool powersave) +{ + struct ieee80211_vif *vif = avp->vif; + struct ieee80211_sta *sta = NULL; + struct ieee80211_hdr_3addr *nullfunc; + struct ath_tx_control txctl; + struct sk_buff *skb; + int band = sc->cur_chan->chandef.chan->band; + + switch (vif->type) { + case NL80211_IFTYPE_STATION: + if (!vif->bss_conf.assoc) + return false; + + skb = ieee80211_nullfunc_get(sc->hw, vif); + if (!skb) + return false; + + nullfunc = (struct ieee80211_hdr_3addr *) skb->data; + if (powersave) + nullfunc->frame_control |= + cpu_to_le16(IEEE80211_FCTL_PM); + + skb_set_queue_mapping(skb, IEEE80211_AC_VO); + if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) { + dev_kfree_skb_any(skb); + return false; + } + break; + default: + return false; + } + + memset(&txctl, 0, sizeof(txctl)); + txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO]; + txctl.sta = sta; + txctl.force_channel = true; + if (ath_tx_start(sc->hw, skb, &txctl)) { + ieee80211_free_txskb(sc->hw, skb); + return false; + } + + return true; +} + +void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct ath_vif *avp; + bool active = false; + u8 n_active = 0; + + if (!ctx) + return; + + list_for_each_entry(avp, &ctx->vifs, list) { + struct ieee80211_vif *vif = avp->vif; + + switch (vif->type) { + case NL80211_IFTYPE_P2P_CLIENT: + case NL80211_IFTYPE_STATION: + if (vif->bss_conf.assoc) + active = true; + break; + default: + active = true; + break; + } + } + ctx->active = active; + + ath_for_each_chanctx(sc, ctx) { + if (!ctx->assigned || list_empty(&ctx->vifs)) + continue; + n_active++; + } + + if (n_active <= 1) { + clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags); + return; + } + if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags)) + return; + ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL); +} + +static bool +ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave) +{ + struct ath_vif *avp; + bool sent = false; + + rcu_read_lock(); + list_for_each_entry(avp, &sc->cur_chan->vifs, list) { + if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave)) + sent = true; + } + rcu_read_unlock(); + + return sent; +} + +static bool ath_chanctx_defer_switch(struct ath_softc *sc) +{ + if (sc->cur_chan == &sc->offchannel.chan) + return false; + + switch (sc->sched.state) { + case ATH_CHANCTX_STATE_SWITCH: + return false; + case ATH_CHANCTX_STATE_IDLE: + if (!sc->cur_chan->switch_after_beacon) + return false; + + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON; + break; + default: + break; + } + + return true; +} + +static void ath_chanctx_set_next(struct ath_softc *sc, bool force) +{ + struct timespec ts; + bool measure_time = false; + bool send_ps = false; + + spin_lock_bh(&sc->chan_lock); + if (!sc->next_chan) { + spin_unlock_bh(&sc->chan_lock); + return; + } + + if (!force && ath_chanctx_defer_switch(sc)) { + spin_unlock_bh(&sc->chan_lock); + return; + } + + if (sc->cur_chan != sc->next_chan) { + sc->cur_chan->stopped = true; + spin_unlock_bh(&sc->chan_lock); + + if (sc->next_chan == &sc->offchannel.chan) { + getrawmonotonic(&ts); + measure_time = true; + } + __ath9k_flush(sc->hw, ~0, true); + + if (ath_chanctx_send_ps_frame(sc, true)) + __ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO), false); + + send_ps = true; + spin_lock_bh(&sc->chan_lock); + + if (sc->cur_chan != &sc->offchannel.chan) { + getrawmonotonic(&sc->cur_chan->tsf_ts); + sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah); + } + } + sc->cur_chan = sc->next_chan; + sc->cur_chan->stopped = false; + sc->next_chan = NULL; + sc->sched.offchannel_duration = 0; + if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE) + sc->sched.state = ATH_CHANCTX_STATE_IDLE; + + spin_unlock_bh(&sc->chan_lock); + + if (sc->sc_ah->chip_fullsleep || + memcmp(&sc->cur_chandef, &sc->cur_chan->chandef, + sizeof(sc->cur_chandef))) { + ath_set_channel(sc); + if (measure_time) + sc->sched.channel_switch_time = + ath9k_hw_get_tsf_offset(&ts, NULL); + } + if (send_ps) + ath_chanctx_send_ps_frame(sc, false); + + ath_offchannel_channel_change(sc); + ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH); +} + +void ath_chanctx_work(struct work_struct *work) +{ + struct ath_softc *sc = container_of(work, struct ath_softc, + chanctx_work); + mutex_lock(&sc->mutex); + ath_chanctx_set_next(sc, false); + mutex_unlock(&sc->mutex); +} + +void ath_chanctx_init(struct ath_softc *sc) +{ + struct ath_chanctx *ctx; + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct ieee80211_supported_band *sband; + struct ieee80211_channel *chan; + int i, j; + + sband = &common->sbands[IEEE80211_BAND_2GHZ]; + if (!sband->n_channels) + sband = &common->sbands[IEEE80211_BAND_5GHZ]; + + chan = &sband->channels[0]; + for (i = 0; i < ATH9K_NUM_CHANCTX; i++) { + ctx = &sc->chanctx[i]; + cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20); + INIT_LIST_HEAD(&ctx->vifs); + ctx->txpower = ATH_TXPOWER_MAX; + for (j = 0; j < ARRAY_SIZE(ctx->acq); j++) + INIT_LIST_HEAD(&ctx->acq[j]); + } + ctx = &sc->offchannel.chan; + cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20); + INIT_LIST_HEAD(&ctx->vifs); + ctx->txpower = ATH_TXPOWER_MAX; + for (j = 0; j < ARRAY_SIZE(ctx->acq); j++) + INIT_LIST_HEAD(&ctx->acq[j]); + sc->offchannel.chan.offchannel = true; + +} + +void ath9k_chanctx_force_active(struct ieee80211_hw *hw, + struct ieee80211_vif *vif) +{ + struct ath_softc *sc = hw->priv; + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + struct ath_vif *avp = (struct ath_vif *) vif->drv_priv; + bool changed = false; + + if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags)) + return; + + if (!avp->chanctx) + return; + + mutex_lock(&sc->mutex); + + spin_lock_bh(&sc->chan_lock); + if (sc->next_chan || (sc->cur_chan != avp->chanctx)) { + sc->next_chan = avp->chanctx; + changed = true; + } + sc->sched.state = ATH_CHANCTX_STATE_FORCE_ACTIVE; + spin_unlock_bh(&sc->chan_lock); + + if (changed) + ath_chanctx_set_next(sc, true); + + mutex_unlock(&sc->mutex); +} + +void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx, + struct cfg80211_chan_def *chandef) +{ + struct ath_common *common = ath9k_hw_common(sc->sc_ah); + + spin_lock_bh(&sc->chan_lock); + + if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) && + (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) { + sc->sched.offchannel_pending = true; + spin_unlock_bh(&sc->chan_lock); + return; + } + + sc->next_chan = ctx; + if (chandef) + ctx->chandef = *chandef; + + if (sc->next_chan == &sc->offchannel.chan) { + sc->sched.offchannel_duration = + TU_TO_USEC(sc->offchannel.duration) + + sc->sched.channel_switch_time; + } + spin_unlock_bh(&sc->chan_lock); + ieee80211_queue_work(sc->hw, &sc->chanctx_work); +} + +void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx, + struct cfg80211_chan_def *chandef) +{ + bool cur_chan; + + spin_lock_bh(&sc->chan_lock); + if (chandef) + memcpy(&ctx->chandef, chandef, sizeof(*chandef)); + cur_chan = sc->cur_chan == ctx; + spin_unlock_bh(&sc->chan_lock); + + if (!cur_chan) + return; + + ath_set_channel(sc); +} + +struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc, bool active) +{ + struct ath_chanctx *ctx; + + ath_for_each_chanctx(sc, ctx) { + if (!ctx->assigned || list_empty(&ctx->vifs)) + continue; + if (active && !ctx->active) + continue; + + if (ctx->switch_after_beacon) + return ctx; + } + + return &sc->chanctx[0]; +} + +void ath_chanctx_offchan_switch(struct ath_softc *sc, + struct ieee80211_channel *chan) +{ + struct cfg80211_chan_def chandef; + + cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT); + + ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef); +} + +static struct ath_chanctx * +ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx) +{ + int idx = ctx - &sc->chanctx[0]; + + return &sc->chanctx[!idx]; +} + +static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc) +{ + struct ath_chanctx *prev, *cur; + struct timespec ts; + u32 cur_tsf, prev_tsf, beacon_int; + s32 offset; + + beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval); + + cur = sc->cur_chan; + prev = ath_chanctx_get_next(sc, cur); + + getrawmonotonic(&ts); + cur_tsf = (u32) cur->tsf_val + + ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts); + + prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf; + prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts); + + /* Adjust the TSF time of the AP chanctx to keep its beacons + * at half beacon interval offset relative to the STA chanctx. + */ + offset = cur_tsf - prev_tsf; + + /* Ignore stale data or spurious timestamps */ + if (offset < 0 || offset > 3 * beacon_int) + return; + + offset = beacon_int / 2 - (offset % beacon_int); + prev->tsf_val += offset; +} + +void ath_chanctx_timer(unsigned long data) +{ + struct ath_softc *sc = (struct ath_softc *) data; + + ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER); +} + +/* Configure the TSF based hardware timer for a channel switch. + * Also set up backup software timer, in case the gen timer fails. + * This could be caused by a hardware reset. + */ +static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time) +{ + struct ath_hw *ah = sc->sc_ah; + + ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000); + tsf_time -= ath9k_hw_gettsf32(ah); + tsf_time = msecs_to_jiffies(tsf_time / 1000) + 1; + mod_timer(&sc->sched.timer, tsf_time); +} + +void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif, + enum ath_chanctx_event ev) +{ + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + struct ath_beacon_config *cur_conf; + struct ath_vif *avp = NULL; + struct ath_chanctx *ctx; + u32 tsf_time; + u32 beacon_int; + bool noa_changed = false; + + if (vif) + avp = (struct ath_vif *) vif->drv_priv; + + spin_lock_bh(&sc->chan_lock); + + switch (ev) { + case ATH_CHANCTX_EVENT_BEACON_PREPARE: + if (avp->offchannel_duration) + avp->offchannel_duration = 0; + + if (avp->chanctx != sc->cur_chan) + break; + + if (sc->sched.offchannel_pending) { + sc->sched.offchannel_pending = false; + sc->next_chan = &sc->offchannel.chan; + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON; + } + + ctx = ath_chanctx_get_next(sc, sc->cur_chan); + if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) { + sc->next_chan = ctx; + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON; + } + + /* if the timer missed its window, use the next interval */ + if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER) + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON; + + if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON) + break; + + sc->sched.beacon_pending = true; + sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER); + + cur_conf = &sc->cur_chan->beacon; + beacon_int = TU_TO_USEC(cur_conf->beacon_interval); + + /* defer channel switch by a quarter beacon interval */ + tsf_time = sc->sched.next_tbtt + beacon_int / 4; + sc->sched.switch_start_time = tsf_time; + sc->cur_chan->last_beacon = sc->sched.next_tbtt; + + /* Prevent wrap-around issues */ + if (avp->periodic_noa_duration && + tsf_time - avp->periodic_noa_start > BIT(30)) + avp->periodic_noa_duration = 0; + + if (ctx->active && !avp->periodic_noa_duration) { + avp->periodic_noa_start = tsf_time; + avp->periodic_noa_duration = + TU_TO_USEC(cur_conf->beacon_interval) / 2 - + sc->sched.channel_switch_time; + noa_changed = true; + } else if (!ctx->active && avp->periodic_noa_duration) { + avp->periodic_noa_duration = 0; + noa_changed = true; + } + + /* If at least two consecutive beacons were missed on the STA + * chanctx, stay on the STA channel for one extra beacon period, + * to resync the timer properly. + */ + if (ctx->active && sc->sched.beacon_miss >= 2) + sc->sched.offchannel_duration = 3 * beacon_int / 2; + + if (sc->sched.offchannel_duration) { + noa_changed = true; + avp->offchannel_start = tsf_time; + avp->offchannel_duration = + sc->sched.offchannel_duration; + } + + if (noa_changed) + avp->noa_index++; + break; + case ATH_CHANCTX_EVENT_BEACON_SENT: + if (!sc->sched.beacon_pending) + break; + + sc->sched.beacon_pending = false; + if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON) + break; + + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER; + ath_chanctx_setup_timer(sc, sc->sched.switch_start_time); + break; + case ATH_CHANCTX_EVENT_TSF_TIMER: + if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER) + break; + + if (!sc->cur_chan->switch_after_beacon && + sc->sched.beacon_pending) + sc->sched.beacon_miss++; + + sc->sched.state = ATH_CHANCTX_STATE_SWITCH; + ieee80211_queue_work(sc->hw, &sc->chanctx_work); + break; + case ATH_CHANCTX_EVENT_BEACON_RECEIVED: + if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) || + sc->cur_chan == &sc->offchannel.chan) + break; + + ath_chanctx_adjust_tbtt_delta(sc); + sc->sched.beacon_pending = false; + sc->sched.beacon_miss = 0; + + /* TSF time might have been updated by the incoming beacon, + * need update the channel switch timer to reflect the change. + */ + tsf_time = sc->sched.switch_start_time; + tsf_time -= (u32) sc->cur_chan->tsf_val + + ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL); + tsf_time += ath9k_hw_gettsf32(ah); + + + ath_chanctx_setup_timer(sc, tsf_time); + break; + case ATH_CHANCTX_EVENT_ASSOC: + if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE || + avp->chanctx != sc->cur_chan) + break; + + sc->sched.state = ATH_CHANCTX_STATE_IDLE; + /* fall through */ + case ATH_CHANCTX_EVENT_SWITCH: + if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) || + sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE || + sc->cur_chan->switch_after_beacon || + sc->cur_chan == &sc->offchannel.chan) + break; + + /* If this is a station chanctx, stay active for a half + * beacon period (minus channel switch time) + */ + sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan); + cur_conf = &sc->cur_chan->beacon; + + sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER; + + tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2; + if (sc->sched.beacon_miss >= 2) { + sc->sched.beacon_miss = 0; + tsf_time *= 3; + } + + tsf_time -= sc->sched.channel_switch_time; + tsf_time += ath9k_hw_gettsf32(sc->sc_ah); + sc->sched.switch_start_time = tsf_time; + + ath_chanctx_setup_timer(sc, tsf_time); + sc->sched.beacon_pending = true; + break; + case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL: + if (sc->cur_chan == &sc->offchannel.chan || + sc->cur_chan->switch_after_beacon) + break; + + sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan); + ieee80211_queue_work(sc->hw, &sc->chanctx_work); + break; + case ATH_CHANCTX_EVENT_UNASSIGN: + if (sc->cur_chan->assigned) { + if (sc->next_chan && !sc->next_chan->assigned && + sc->next_chan != &sc->offchannel.chan) + sc->sched.state = ATH_CHANCTX_STATE_IDLE; + break; + } + + ctx = ath_chanctx_get_next(sc, sc->cur_chan); + sc->sched.state = ATH_CHANCTX_STATE_IDLE; + if (!ctx->assigned) + break; + + sc->next_chan = ctx; + ieee80211_queue_work(sc->hw, &sc->chanctx_work); + break; + } + + spin_unlock_bh(&sc->chan_lock); +} |