htc_drv_beacon.c

/*
 * Copyright (c) 2010 Atheros Communications 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 "htc.h"

#define FUDGE 2

static void ath9k_htc_beacon_config_sta(struct ath9k_htc_priv *priv,
					struct htc_beacon_config *bss_conf)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct ath9k_beacon_state bs;
	enum ath9k_int imask = 0;
	int dtimperiod, dtimcount, sleepduration;
	int cfpperiod, cfpcount, bmiss_timeout;
	u32 nexttbtt = 0, intval, tsftu;
	__be32 htc_imask = 0;
	u64 tsf;
	int num_beacons, offset, dtim_dec_count, cfp_dec_count;
	int ret;
	u8 cmd_rsp;

	memset(&bs, 0, sizeof(bs));

	intval = bss_conf->beacon_interval & ATH9K_BEACON_PERIOD;
	bmiss_timeout = (ATH_DEFAULT_BMISS_LIMIT * bss_conf->beacon_interval);

	/*
	 * Setup dtim and cfp parameters according to
	 * last beacon we received (which may be none).
	 */
	dtimperiod = bss_conf->dtim_period;
	if (dtimperiod <= 0)		/* NB: 0 if not known */
		dtimperiod = 1;
	dtimcount = 1;
	if (dtimcount >= dtimperiod)	/* NB: sanity check */
		dtimcount = 0;
	cfpperiod = 1;			/* NB: no PCF support yet */
	cfpcount = 0;

	sleepduration = intval;
	if (sleepduration <= 0)
		sleepduration = intval;

	/*
	 * Pull nexttbtt forward to reflect the current
	 * TSF and calculate dtim+cfp state for the result.
	 */
	tsf = ath9k_hw_gettsf64(priv->ah);
	tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;

	num_beacons = tsftu / intval + 1;
	offset = tsftu % intval;
	nexttbtt = tsftu - offset;
	if (offset)
		nexttbtt += intval;

	/* DTIM Beacon every dtimperiod Beacon */
	dtim_dec_count = num_beacons % dtimperiod;
	/* CFP every cfpperiod DTIM Beacon */
	cfp_dec_count = (num_beacons / dtimperiod) % cfpperiod;
	if (dtim_dec_count)
		cfp_dec_count++;

	dtimcount -= dtim_dec_count;
	if (dtimcount < 0)
		dtimcount += dtimperiod;

	cfpcount -= cfp_dec_count;
	if (cfpcount < 0)
		cfpcount += cfpperiod;

	bs.bs_intval = intval;
	bs.bs_nexttbtt = nexttbtt;
	bs.bs_dtimperiod = dtimperiod*intval;
	bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
	bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
	bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
	bs.bs_cfpmaxduration = 0;

	/*
	 * Calculate the number of consecutive beacons to miss* before taking
	 * a BMISS interrupt. The configuration is specified in TU so we only
	 * need calculate based	on the beacon interval.  Note that we clamp the
	 * result to at most 15 beacons.
	 */
	if (sleepduration > intval) {
		bs.bs_bmissthreshold = ATH_DEFAULT_BMISS_LIMIT / 2;
	} else {
		bs.bs_bmissthreshold = DIV_ROUND_UP(bmiss_timeout, intval);
		if (bs.bs_bmissthreshold > 15)
			bs.bs_bmissthreshold = 15;
		else if (bs.bs_bmissthreshold <= 0)
			bs.bs_bmissthreshold = 1;
	}

	/*
	 * Calculate sleep duration. The configuration is given in ms.
	 * We ensure a multiple of the beacon period is used. Also, if the sleep
	 * duration is greater than the DTIM period then it makes senses
	 * to make it a multiple of that.
	 *
	 * XXX fixed at 100ms
	 */

	bs.bs_sleepduration = roundup(IEEE80211_MS_TO_TU(100), sleepduration);
	if (bs.bs_sleepduration > bs.bs_dtimperiod)
		bs.bs_sleepduration = bs.bs_dtimperiod;

	/* TSF out of range threshold fixed at 1 second */
	bs.bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;

	ath_dbg(common, ATH_DBG_CONFIG, "intval: %u tsf: %llu tsftu: %u\n",
		intval, tsf, tsftu);
	ath_dbg(common, ATH_DBG_CONFIG,
		"bmiss: %u sleep: %u cfp-period: %u maxdur: %u next: %u\n",
		bs.bs_bmissthreshold, bs.bs_sleepduration,
		bs.bs_cfpperiod, bs.bs_cfpmaxduration, bs.bs_cfpnext);

	/* Set the computed STA beacon timers */

	WMI_CMD(WMI_DISABLE_INTR_CMDID);
	ath9k_hw_set_sta_beacon_timers(priv->ah, &bs);
	imask |= ATH9K_INT_BMISS;
	htc_imask = cpu_to_be32(imask);
	WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
}

static void ath9k_htc_beacon_config_ap(struct ath9k_htc_priv *priv,
				       struct htc_beacon_config *bss_conf)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	enum ath9k_int imask = 0;
	u32 nexttbtt, intval, tsftu;
	__be32 htc_imask = 0;
	int ret;
	u8 cmd_rsp;
	u64 tsf;

	intval = bss_conf->beacon_interval & ATH9K_BEACON_PERIOD;
	intval /= ATH9K_HTC_MAX_BCN_VIF;
	nexttbtt = intval;

	if (priv->op_flags & OP_TSF_RESET) {
		ath9k_hw_reset_tsf(priv->ah);
		priv->op_flags &= ~OP_TSF_RESET;
	} else {
		/*
		 * Pull nexttbtt forward to reflect the current TSF.
		 */
		tsf = ath9k_hw_gettsf64(priv->ah);
		tsftu = TSF_TO_TU(tsf >> 32, tsf) + FUDGE;
		do {
			nexttbtt += intval;
		} while (nexttbtt < tsftu);
	}

	if (priv->op_flags & OP_ENABLE_BEACON)
		imask |= ATH9K_INT_SWBA;

	ath_dbg(common, ATH_DBG_CONFIG,
		"AP Beacon config, intval: %d, nexttbtt: %u "
		"imask: 0x%x\n",
		bss_conf->beacon_interval, nexttbtt, imask);

	WMI_CMD(WMI_DISABLE_INTR_CMDID);
	ath9k_hw_beaconinit(priv->ah, TU_TO_USEC(nexttbtt), TU_TO_USEC(intval));
	priv->cur_beacon_conf.bmiss_cnt = 0;
	htc_imask = cpu_to_be32(imask);
	WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
}

static void ath9k_htc_beacon_config_adhoc(struct ath9k_htc_priv *priv,
					  struct htc_beacon_config *bss_conf)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	enum ath9k_int imask = 0;
	u32 nexttbtt, intval, tsftu;
	__be32 htc_imask = 0;
	int ret;
	u8 cmd_rsp;
	u64 tsf;

	intval = bss_conf->beacon_interval & ATH9K_BEACON_PERIOD;
	nexttbtt = intval;

	/*
	 * Pull nexttbtt forward to reflect the current TSF.
	 */
	tsf = ath9k_hw_gettsf64(priv->ah);
	tsftu = TSF_TO_TU(tsf >> 32, tsf) + FUDGE;
	do {
		nexttbtt += intval;
	} while (nexttbtt < tsftu);

	if (priv->op_flags & OP_ENABLE_BEACON)
		imask |= ATH9K_INT_SWBA;

	ath_dbg(common, ATH_DBG_CONFIG,
		"IBSS Beacon config, intval: %d, nexttbtt: %u, imask: 0x%x\n",
		bss_conf->beacon_interval, nexttbtt, imask);

	WMI_CMD(WMI_DISABLE_INTR_CMDID);
	ath9k_hw_beaconinit(priv->ah, TU_TO_USEC(nexttbtt), TU_TO_USEC(intval));
	priv->cur_beacon_conf.bmiss_cnt = 0;
	htc_imask = cpu_to_be32(imask);
	WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
}

void ath9k_htc_beaconep(void *drv_priv, struct sk_buff *skb,
			enum htc_endpoint_id ep_id, bool txok)
{
	dev_kfree_skb_any(skb);
}

static void ath9k_htc_send_beacon(struct ath9k_htc_priv *priv,
				  int slot)
{
	struct ieee80211_vif *vif;
	struct ath9k_htc_vif *avp;
	struct tx_beacon_header beacon_hdr;
	struct ath9k_htc_tx_ctl tx_ctl;
	struct ieee80211_tx_info *info;
	struct sk_buff *beacon;
	u8 *tx_fhdr;

	memset(&beacon_hdr, 0, sizeof(struct tx_beacon_header));
	memset(&tx_ctl, 0, sizeof(struct ath9k_htc_tx_ctl));

	spin_lock_bh(&priv->beacon_lock);

	vif = priv->cur_beacon_conf.bslot[slot];
	avp = (struct ath9k_htc_vif *)vif->drv_priv;

	if (unlikely(priv->op_flags & OP_SCANNING)) {
		spin_unlock_bh(&priv->beacon_lock);
		return;
	}

	/* Get a new beacon */
	beacon = ieee80211_beacon_get(priv->hw, vif);
	if (!beacon) {
		spin_unlock_bh(&priv->beacon_lock);
		return;
	}

	info = IEEE80211_SKB_CB(beacon);
	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
		struct ieee80211_hdr *hdr =
			(struct ieee80211_hdr *) beacon->data;
		avp->seq_no += 0x10;
		hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
		hdr->seq_ctrl |= cpu_to_le16(avp->seq_no);
	}

	tx_ctl.type = ATH9K_HTC_NORMAL;
	beacon_hdr.vif_index = avp->index;
	tx_fhdr = skb_push(beacon, sizeof(beacon_hdr));
	memcpy(tx_fhdr, (u8 *) &beacon_hdr, sizeof(beacon_hdr));

	htc_send(priv->htc, beacon, priv->beacon_ep, &tx_ctl);

	spin_unlock_bh(&priv->beacon_lock);
}

static int ath9k_htc_choose_bslot(struct ath9k_htc_priv *priv)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	unsigned long flags;
	u64 tsf;
	u32 tsftu;
	u16 intval;
	int slot;

	intval = priv->cur_beacon_conf.beacon_interval & ATH9K_BEACON_PERIOD;

	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
	tsf = priv->wmi->tsf;
	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);

	tsftu = TSF_TO_TU(tsf >> 32, tsf);
	slot = ((tsftu % intval) * ATH9K_HTC_MAX_BCN_VIF) / intval;
	slot = ATH9K_HTC_MAX_BCN_VIF - slot - 1;

	ath_dbg(common, ATH_DBG_BEACON,
		"Choose slot: %d, tsf: %llu, tsftu: %u, intval: %u\n",
		slot, tsf, tsftu, intval);

	return slot;
}

void ath9k_htc_swba(struct ath9k_htc_priv *priv)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	unsigned long flags;
	int slot;

	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
	if (priv->wmi->beacon_pending != 0) {
		spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);
		priv->cur_beacon_conf.bmiss_cnt++;
		if (priv->cur_beacon_conf.bmiss_cnt > BSTUCK_THRESHOLD) {
			ath_dbg(common, ATH_DBG_BEACON,
				"Beacon stuck, HW reset\n");
			ath9k_htc_reset(priv);
		}
		return;
	}
	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);

	if (priv->cur_beacon_conf.bmiss_cnt) {
		ath_dbg(common, ATH_DBG_BEACON,
			"Resuming beacon xmit after %u misses\n",
			priv->cur_beacon_conf.bmiss_cnt);
		priv->cur_beacon_conf.bmiss_cnt = 0;
	}

	slot = ath9k_htc_choose_bslot(priv);
	spin_lock_bh(&priv->beacon_lock);
	if (priv->cur_beacon_conf.bslot[slot] == NULL) {
		spin_unlock_bh(&priv->beacon_lock);
		return;
	}
	spin_unlock_bh(&priv->beacon_lock);

	ath9k_htc_send_beacon(priv, slot);
}

/* Currently, only for IBSS */
void ath9k_htc_beaconq_config(struct ath9k_htc_priv *priv)
{
	struct ath_hw *ah = priv->ah;
	struct ath9k_tx_queue_info qi, qi_be;
	int qnum = priv->hwq_map[WME_AC_BE];

	memset(&qi, 0, sizeof(struct ath9k_tx_queue_info));
	memset(&qi_be, 0, sizeof(struct ath9k_tx_queue_info));

	ath9k_hw_get_txq_props(ah, qnum, &qi_be);

	qi.tqi_aifs = qi_be.tqi_aifs;
	/* For WIFI Beacon Distribution
	 * Long slot time  : 2x cwmin
	 * Short slot time : 4x cwmin
	 */
	if (ah->slottime == ATH9K_SLOT_TIME_20)
		qi.tqi_cwmin = 2*qi_be.tqi_cwmin;
	else
		qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
	qi.tqi_cwmax = qi_be.tqi_cwmax;

	if (!ath9k_hw_set_txq_props(ah, priv->beaconq, &qi)) {
		ath_err(ath9k_hw_common(ah),
			"Unable to update beacon queue %u!\n", qnum);
	} else {
		ath9k_hw_resettxqueue(ah, priv->beaconq);
	}
}

void ath9k_htc_assign_bslot(struct ath9k_htc_priv *priv,
			    struct ieee80211_vif *vif)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *)vif->drv_priv;
	int i = 0;

	spin_lock_bh(&priv->beacon_lock);
	for (i = 0; i < ATH9K_HTC_MAX_BCN_VIF; i++) {
		if (priv->cur_beacon_conf.bslot[i] == NULL) {
			avp->bslot = i;
			break;
		}
	}

	priv->cur_beacon_conf.bslot[avp->bslot] = vif;
	spin_unlock_bh(&priv->beacon_lock);

	ath_dbg(common, ATH_DBG_CONFIG,
		"Added interface at beacon slot: %d\n", avp->bslot);
}

void ath9k_htc_remove_bslot(struct ath9k_htc_priv *priv,
			    struct ieee80211_vif *vif)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *)vif->drv_priv;

	spin_lock_bh(&priv->beacon_lock);
	priv->cur_beacon_conf.bslot[avp->bslot] = NULL;
	spin_unlock_bh(&priv->beacon_lock);

	ath_dbg(common, ATH_DBG_CONFIG,
		"Removed interface at beacon slot: %d\n", avp->bslot);
}

static void ath9k_htc_beacon_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
{
	bool *beacon_configured = (bool *)data;
	struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *) vif->drv_priv;

	if (vif->type == NL80211_IFTYPE_STATION &&
	    avp->beacon_configured)
		*beacon_configured = true;
}

static bool ath9k_htc_check_beacon_config(struct ath9k_htc_priv *priv,
					  struct ieee80211_vif *vif)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct htc_beacon_config *cur_conf = &priv->cur_beacon_conf;
	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
	bool beacon_configured;

	/*
	 * Changing the beacon interval when multiple AP interfaces
	 * are configured will affect beacon transmission of all
	 * of them.
	 */
	if ((priv->ah->opmode == NL80211_IFTYPE_AP) &&
	    (priv->num_ap_vif > 1) &&
	    (vif->type == NL80211_IFTYPE_AP) &&
	    (cur_conf->beacon_interval != bss_conf->beacon_int)) {
		ath_dbg(common, ATH_DBG_CONFIG,
			"Changing beacon interval of multiple AP interfaces !\n");
		return false;
	}

	/*
	 * If the HW is operating in AP mode, any new station interfaces that
	 * are added cannot change the beacon parameters.
	 */
	if (priv->num_ap_vif &&
	    (vif->type != NL80211_IFTYPE_AP)) {
		ath_dbg(common, ATH_DBG_CONFIG,
			"HW in AP mode, cannot set STA beacon parameters\n");
		return false;
	}

	/*
	 * The beacon parameters are configured only for the first
	 * station interface.
	 */
	if ((priv->ah->opmode == NL80211_IFTYPE_STATION) &&
	    (priv->num_sta_vif > 1) &&
	    (vif->type == NL80211_IFTYPE_STATION)) {
		beacon_configured = false;
		ieee80211_iterate_active_interfaces_atomic(priv->hw,
							   ath9k_htc_beacon_iter,
							   &beacon_configured);

		if (beacon_configured) {
			ath_dbg(common, ATH_DBG_CONFIG,
				"Beacon already configured for a station interface\n");
			return false;
		}
	}

	return true;
}

void ath9k_htc_beacon_config(struct ath9k_htc_priv *priv,
			     struct ieee80211_vif *vif)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct htc_beacon_config *cur_conf = &priv->cur_beacon_conf;
	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
	struct ath9k_htc_vif *avp = (struct ath9k_htc_vif *) vif->drv_priv;

	if (!ath9k_htc_check_beacon_config(priv, vif))
		return;

	cur_conf->beacon_interval = bss_conf->beacon_int;
	if (cur_conf->beacon_interval == 0)
		cur_conf->beacon_interval = 100;

	cur_conf->dtim_period = bss_conf->dtim_period;
	cur_conf->bmiss_timeout =
		ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;

	switch (vif->type) {
	case NL80211_IFTYPE_STATION:
		ath9k_htc_beacon_config_sta(priv, cur_conf);
		avp->beacon_configured = true;
		break;
	case NL80211_IFTYPE_ADHOC:
		ath9k_htc_beacon_config_adhoc(priv, cur_conf);
		break;
	case NL80211_IFTYPE_AP:
		ath9k_htc_beacon_config_ap(priv, cur_conf);
		break;
	default:
		ath_dbg(common, ATH_DBG_CONFIG,
			"Unsupported beaconing mode\n");
		return;
	}
}

void ath9k_htc_beacon_reconfig(struct ath9k_htc_priv *priv)
{
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct htc_beacon_config *cur_conf = &priv->cur_beacon_conf;

	switch (priv->ah->opmode) {
	case NL80211_IFTYPE_STATION:
		ath9k_htc_beacon_config_sta(priv, cur_conf);
		break;
	case NL80211_IFTYPE_ADHOC:
		ath9k_htc_beacon_config_adhoc(priv, cur_conf);
		break;
	case NL80211_IFTYPE_AP:
		ath9k_htc_beacon_config_ap(priv, cur_conf);
		break;
	default:
		ath_dbg(common, ATH_DBG_CONFIG,
			"Unsupported beaconing mode\n");
		return;
	}
}