iwlwifi: trigger scan synchronously

Scan requesting doesn't need to be asynchronous
since all code paths leading up to it can sleep.
Make the scan request a new util operation that
is hw-specific (to account for 3945 vs. agn)
and call it right in place.

This patch moves a lot of code into iwlagn as
it need not be in iwlcore.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 395 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index c465c8590833..048c6156d3be 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -1111,3 +1111,398 @@ void iwlagn_rx_reply_rx_phy(struct iwl_priv *priv,
 	memcpy(&priv->_agn.last_phy_res, pkt->u.raw,
 	       sizeof(struct iwl_rx_phy_res));
 }
+
+static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
+				     enum ieee80211_band band,
+				     struct iwl_scan_channel *scan_ch)
+{
+	const struct ieee80211_supported_band *sband;
+	const struct iwl_channel_info *ch_info;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int i, added = 0;
+	u16 channel = 0;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband) {
+		IWL_ERR(priv, "invalid band\n");
+		return added;
+	}
+
+	active_dwell = iwl_get_active_dwell_time(priv, band, 0);
+	passive_dwell = iwl_get_passive_dwell_time(priv, band);
+
+	if (passive_dwell <= active_dwell)
+		passive_dwell = active_dwell + 1;
+
+	/* only scan single channel, good enough to reset the RF */
+	/* pick the first valid not in-use channel */
+	if (band == IEEE80211_BAND_5GHZ) {
+		for (i = 14; i < priv->channel_count; i++) {
+			if (priv->channel_info[i].channel !=
+			    le16_to_cpu(priv->staging_rxon.channel)) {
+				channel = priv->channel_info[i].channel;
+				ch_info = iwl_get_channel_info(priv,
+					band, channel);
+				if (is_channel_valid(ch_info))
+					break;
+			}
+		}
+	} else {
+		for (i = 0; i < 14; i++) {
+			if (priv->channel_info[i].channel !=
+			    le16_to_cpu(priv->staging_rxon.channel)) {
+					channel =
+						priv->channel_info[i].channel;
+					ch_info = iwl_get_channel_info(priv,
+						band, channel);
+					if (is_channel_valid(ch_info))
+						break;
+			}
+		}
+	}
+	if (channel) {
+		scan_ch->channel = cpu_to_le16(channel);
+		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		scan_ch->active_dwell = cpu_to_le16(active_dwell);
+		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+		if (band == IEEE80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+		added++;
+	} else
+		IWL_ERR(priv, "no valid channel found\n");
+	return added;
+}
+
+static int iwl_get_channels_for_scan(struct iwl_priv *priv,
+				     enum ieee80211_band band,
+				     u8 is_active, u8 n_probes,
+				     struct iwl_scan_channel *scan_ch)
+{
+	struct ieee80211_channel *chan;
+	const struct ieee80211_supported_band *sband;
+	const struct iwl_channel_info *ch_info;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int added, i;
+	u16 channel;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband)
+		return 0;
+
+	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
+	passive_dwell = iwl_get_passive_dwell_time(priv, band);
+
+	if (passive_dwell <= active_dwell)
+		passive_dwell = active_dwell + 1;
+
+	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
+		chan = priv->scan_request->channels[i];
+
+		if (chan->band != band)
+			continue;
+
+		channel = ieee80211_frequency_to_channel(chan->center_freq);
+		scan_ch->channel = cpu_to_le16(channel);
+
+		ch_info = iwl_get_channel_info(priv, band, channel);
+		if (!is_channel_valid(ch_info)) {
+			IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
+					channel);
+			continue;
+		}
+
+		if (!is_active || is_channel_passive(ch_info) ||
+		    (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
+			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		else
+			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
+
+		if (n_probes)
+			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
+
+		scan_ch->active_dwell = cpu_to_le16(active_dwell);
+		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+
+		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
+		 * power level:
+		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
+		 */
+		if (band == IEEE80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+
+		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
+			       channel, le32_to_cpu(scan_ch->type),
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+				"ACTIVE" : "PASSIVE",
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+			       active_dwell : passive_dwell);
+
+		scan_ch++;
+		added++;
+	}
+
+	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
+	return added;
+}
+
+void iwlagn_request_scan(struct iwl_priv *priv)
+{
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_CMD,
+		.len = sizeof(struct iwl_scan_cmd),
+		.flags = CMD_SIZE_HUGE,
+	};
+	struct iwl_scan_cmd *scan;
+	struct ieee80211_conf *conf = NULL;
+	u32 rate_flags = 0;
+	u16 cmd_len;
+	u16 rx_chain = 0;
+	enum ieee80211_band band;
+	u8 n_probes = 0;
+	u8 rx_ant = priv->hw_params.valid_rx_ant;
+	u8 rate;
+	bool is_active = false;
+	int  chan_mod;
+	u8 active_chains;
+
+	conf = ieee80211_get_hw_conf(priv->hw);
+
+	cancel_delayed_work(&priv->scan_check);
+
+	if (!iwl_is_ready(priv)) {
+		IWL_WARN(priv, "request scan called when driver not ready.\n");
+		goto done;
+	}
+
+	/* Make sure the scan wasn't canceled before this queued work
+	 * was given the chance to run... */
+	if (!test_bit(STATUS_SCANNING, &priv->status))
+		goto done;
+
+	/* This should never be called or scheduled if there is currently
+	 * a scan active in the hardware. */
+	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
+		IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
+			       "Ignoring second request.\n");
+		goto done;
+	}
+
+	if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
+		goto done;
+	}
+
+	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
+		goto done;
+	}
+
+	if (iwl_is_rfkill(priv)) {
+		IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
+		goto done;
+	}
+
+	if (!test_bit(STATUS_READY, &priv->status)) {
+		IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
+		goto done;
+	}
+
+	if (!priv->scan_cmd) {
+		priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
+					 IWL_MAX_SCAN_SIZE, GFP_KERNEL);
+		if (!priv->scan_cmd) {
+			IWL_DEBUG_SCAN(priv,
+				       "fail to allocate memory for scan\n");
+			goto done;
+		}
+	}
+	scan = priv->scan_cmd;
+	memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
+
+	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
+	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
+
+	if (iwl_is_associated(priv)) {
+		u16 interval = 0;
+		u32 extra;
+		u32 suspend_time = 100;
+		u32 scan_suspend_time = 100;
+		unsigned long flags;
+
+		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
+		spin_lock_irqsave(&priv->lock, flags);
+		interval = priv->beacon_int;
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+		scan->suspend_time = 0;
+		scan->max_out_time = cpu_to_le32(200 * 1024);
+		if (!interval)
+			interval = suspend_time;
+
+		extra = (suspend_time / interval) << 22;
+		scan_suspend_time = (extra |
+		    ((suspend_time % interval) * 1024));
+		scan->suspend_time = cpu_to_le32(scan_suspend_time);
+		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
+			       scan_suspend_time, interval);
+	}
+
+	if (priv->is_internal_short_scan) {
+		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
+	} else if (priv->scan_request->n_ssids) {
+		int i, p = 0;
+		IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
+		for (i = 0; i < priv->scan_request->n_ssids; i++) {
+			/* always does wildcard anyway */
+			if (!priv->scan_request->ssids[i].ssid_len)
+				continue;
+			scan->direct_scan[p].id = WLAN_EID_SSID;
+			scan->direct_scan[p].len =
+				priv->scan_request->ssids[i].ssid_len;
+			memcpy(scan->direct_scan[p].ssid,
+			       priv->scan_request->ssids[i].ssid,
+			       priv->scan_request->ssids[i].ssid_len);
+			n_probes++;
+			p++;
+		}
+		is_active = true;
+	} else
+		IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
+
+	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
+	scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
+	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+
+	switch (priv->scan_band) {
+	case IEEE80211_BAND_2GHZ:
+		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
+		chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
+				       >> RXON_FLG_CHANNEL_MODE_POS;
+		if (chan_mod == CHANNEL_MODE_PURE_40) {
+			rate = IWL_RATE_6M_PLCP;
+		} else {
+			rate = IWL_RATE_1M_PLCP;
+			rate_flags = RATE_MCS_CCK_MSK;
+		}
+		scan->good_CRC_th = 0;
+		break;
+	case IEEE80211_BAND_5GHZ:
+		rate = IWL_RATE_6M_PLCP;
+		/*
+		 * If active scaning is requested but a certain channel
+		 * is marked passive, we can do active scanning if we
+		 * detect transmissions.
+		 */
+		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
+
+		/* Force use of chains B and C (0x6) for scan Rx
+		 * Avoid A (0x1) for the device has off-channel reception
+		 * on A-band.
+		 */
+		if (priv->cfg->off_channel_workaround)
+			rx_ant = ANT_BC;
+		break;
+	default:
+		IWL_WARN(priv, "Invalid scan band count\n");
+		goto done;
+	}
+
+	band = priv->scan_band;
+
+	priv->scan_tx_ant[band] =
+			iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
+	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
+	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
+
+	/* In power save mode use one chain, otherwise use all chains */
+	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
+		/* rx_ant has been set to all valid chains previously */
+		active_chains = rx_ant &
+				((u8)(priv->chain_noise_data.active_chains));
+		if (!active_chains)
+			active_chains = rx_ant;
+
+		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
+				priv->chain_noise_data.active_chains);
+
+		rx_ant = first_antenna(active_chains);
+	}
+	/* MIMO is not used here, but value is required */
+	rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
+	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
+	scan->rx_chain = cpu_to_le16(rx_chain);
+	if (!priv->is_internal_short_scan) {
+		cmd_len = iwl_fill_probe_req(priv,
+					(struct ieee80211_mgmt *)scan->data,
+					priv->scan_request->ie,
+					priv->scan_request->ie_len,
+					IWL_MAX_SCAN_SIZE - sizeof(*scan));
+	} else {
+		cmd_len = iwl_fill_probe_req(priv,
+					(struct ieee80211_mgmt *)scan->data,
+					NULL, 0,
+					IWL_MAX_SCAN_SIZE - sizeof(*scan));
+
+	}
+	scan->tx_cmd.len = cpu_to_le16(cmd_len);
+	if (iwl_is_monitor_mode(priv))
+		scan->filter_flags = RXON_FILTER_PROMISC_MSK;
+
+	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
+			       RXON_FILTER_BCON_AWARE_MSK);
+
+	if (priv->is_internal_short_scan) {
+		scan->channel_count =
+			iwl_get_single_channel_for_scan(priv, band,
+				(void *)&scan->data[le16_to_cpu(
+				scan->tx_cmd.len)]);
+	} else {
+		scan->channel_count =
+			iwl_get_channels_for_scan(priv, band,
+				is_active, n_probes,
+				(void *)&scan->data[le16_to_cpu(
+				scan->tx_cmd.len)]);
+	}
+	if (scan->channel_count == 0) {
+		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
+		goto done;
+	}
+
+	cmd.len += le16_to_cpu(scan->tx_cmd.len) +
+	    scan->channel_count * sizeof(struct iwl_scan_channel);
+	cmd.data = scan;
+	scan->len = cpu_to_le16(cmd.len);
+
+	set_bit(STATUS_SCAN_HW, &priv->status);
+	if (iwl_send_cmd_sync(priv, &cmd))
+		goto done;
+
+	queue_delayed_work(priv->workqueue, &priv->scan_check,
+			   IWL_SCAN_CHECK_WATCHDOG);
+
+	return;
+
+ done:
+	/* Cannot perform scan. Make sure we clear scanning
+	* bits from status so next scan request can be performed.
+	* If we don't clear scanning status bit here all next scan
+	* will fail
+	*/
+	clear_bit(STATUS_SCAN_HW, &priv->status);
+	clear_bit(STATUS_SCANNING, &priv->status);
+	/* inform mac80211 scan aborted */
+	queue_work(priv->workqueue, &priv->scan_completed);
+}