drivers/net/wireless/iwlwifi/mvm/scan.c - nest-hello/linux-3.10 - Git at Google

 /******************************************************************************
  *
  * This file is provided under a dual BSD/GPLv2 license.  When using or
  * redistributing this file, you may do so under either license.
  *
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  * USA
  *
  * The full GNU General Public License is included in this distribution
  * in the file called COPYING.
  *
  * Contact Information:
  *  Intel Linux Wireless <ilw@linux.intel.com>
  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  *
  * BSD LICENSE
  *
  * Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
  *  * Neither the name Intel Corporation nor the names of its
  *    contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  *****************************************************************************/

 #include <linux/etherdevice.h>
 #include <net/mac80211.h>

 #include "mvm.h"
 #include "iwl-eeprom-parse.h"
 #include "fw-api-scan.h"

 #define IWL_PLCP_QUIET_THRESH 1
 #define IWL_ACTIVE_QUIET_TIME 10

 static inline __le16 iwl_mvm_scan_rx_chain(struct iwl_mvm *mvm)
 {
 	u16 rx_chain;
 	u8 rx_ant = iwl_fw_valid_rx_ant(mvm->fw);

 	rx_chain = rx_ant << PHY_RX_CHAIN_VALID_POS;
 	rx_chain |= rx_ant << PHY_RX_CHAIN_FORCE_MIMO_SEL_POS;
 	rx_chain |= rx_ant << PHY_RX_CHAIN_FORCE_SEL_POS;
 	rx_chain |= 0x1 << PHY_RX_CHAIN_DRIVER_FORCE_POS;
 	return cpu_to_le16(rx_chain);
 }

 static inline __le32 iwl_mvm_scan_max_out_time(struct ieee80211_vif *vif)
 {
 	if (vif->bss_conf.assoc)
 		return cpu_to_le32(200 * 1024);
 	else
 		return 0;
 }

 static inline __le32 iwl_mvm_scan_suspend_time(struct ieee80211_vif *vif)
 {
 	if (vif->bss_conf.assoc)
 		return cpu_to_le32(vif->bss_conf.beacon_int);
 	else
 		return 0;
 }

 static inline __le32
 iwl_mvm_scan_rxon_flags(struct cfg80211_scan_request *req)
 {
 	if (req->channels[0]->band == IEEE80211_BAND_2GHZ)
 		return cpu_to_le32(PHY_BAND_24);
 	else
 		return cpu_to_le32(PHY_BAND_5);
 }

 static inline __le32
 iwl_mvm_scan_rate_n_flags(struct iwl_mvm *mvm, enum ieee80211_band band,
 			  bool no_cck)
 {
 	u32 tx_ant;

 	mvm->scan_last_antenna_idx =
 		iwl_mvm_next_antenna(mvm, iwl_fw_valid_tx_ant(mvm->fw),
 				     mvm->scan_last_antenna_idx);
 	tx_ant = BIT(mvm->scan_last_antenna_idx) << RATE_MCS_ANT_POS;

 	if (band == IEEE80211_BAND_2GHZ && !no_cck)
 		return cpu_to_le32(IWL_RATE_1M_PLCP | RATE_MCS_CCK_MSK |
 				   tx_ant);
 	else
 		return cpu_to_le32(IWL_RATE_6M_PLCP | tx_ant);
 }

 /*
  * We insert the SSIDs in an inverted order, because the FW will
  * invert it back. The most prioritized SSID, which is first in the
  * request list, is not copied here, but inserted directly to the probe
  * request.
  */
 static void iwl_mvm_scan_fill_ssids(struct iwl_scan_cmd *cmd,
 				    struct cfg80211_scan_request *req)
 {
 	int fw_idx, req_idx;

 	for (req_idx = req->n_ssids - 1, fw_idx = 0; req_idx > 0;
 	     req_idx--, fw_idx++) {
 		cmd->direct_scan[fw_idx].id = WLAN_EID_SSID;
 		cmd->direct_scan[fw_idx].len = req->ssids[req_idx].ssid_len;
 		memcpy(cmd->direct_scan[fw_idx].ssid,
 		       req->ssids[req_idx].ssid,
 		       req->ssids[req_idx].ssid_len);
 	}
 }

 /*
  * If req->n_ssids > 0, it means we should do an active scan.
  * In case of active scan w/o directed scan, we receive a zero-length SSID
  * just to notify that this scan is active and not passive.
  * In order to notify the FW of the number of SSIDs we wish to scan (including
  * the zero-length one), we need to set the corresponding bits in chan->type,
  * one for each SSID, and set the active bit (first).
  */
 static u16 iwl_mvm_get_active_dwell(enum ieee80211_band band, int n_ssids)
 {
 	if (band == IEEE80211_BAND_2GHZ)
 		return 30  + 3 * (n_ssids + 1);
 	return 20  + 2 * (n_ssids + 1);
 }

 static u16 iwl_mvm_get_passive_dwell(enum ieee80211_band band)
 {
 	return band == IEEE80211_BAND_2GHZ ? 100 + 20 : 100 + 10;
 }

 static void iwl_mvm_scan_fill_channels(struct iwl_scan_cmd *cmd,
 				       struct cfg80211_scan_request *req)
 {
 	u16 passive_dwell = iwl_mvm_get_passive_dwell(req->channels[0]->band);
 	u16 active_dwell = iwl_mvm_get_active_dwell(req->channels[0]->band,
 						    req->n_ssids);
 	struct iwl_scan_channel *chan = (struct iwl_scan_channel *)
 		(cmd->data + le16_to_cpu(cmd->tx_cmd.len));
 	int i;

 	for (i = 0; i < cmd->channel_count; i++) {
 		chan->channel = cpu_to_le16(req->channels[i]->hw_value);
 		chan->type = cpu_to_le32(BIT(req->n_ssids) - 1);
 		if (req->channels[i]->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 			chan->type &= cpu_to_le32(~SCAN_CHANNEL_TYPE_ACTIVE);
 		chan->active_dwell = cpu_to_le16(active_dwell);
 		chan->passive_dwell = cpu_to_le16(passive_dwell);
 		chan->iteration_count = cpu_to_le16(1);
 		chan++;
 	}
 }

 /*
  * Fill in probe request with the following parameters:
  * TA is our vif HW address, which mac80211 ensures we have.
  * Packet is broadcasted, so this is both SA and DA.
  * The probe request IE is made out of two: first comes the most prioritized
  * SSID if a directed scan is requested. Second comes whatever extra
  * information was given to us as the scan request IE.
  */
 static u16 iwl_mvm_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 				  int n_ssids, const u8 *ssid, int ssid_len,
 				  const u8 *ie, int ie_len,
 				  int left)
 {
 	int len = 0;
 	u8 *pos = NULL;

 	/* Make sure there is enough space for the probe request,
 	 * two mandatory IEs and the data */
 	left -= 24;
 	if (left < 0)
 		return 0;

 	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 	eth_broadcast_addr(frame->da);
 	memcpy(frame->sa, ta, ETH_ALEN);
 	eth_broadcast_addr(frame->bssid);
 	frame->seq_ctrl = 0;

 	len += 24;

 	/* for passive scans, no need to fill anything */
 	if (n_ssids == 0)
 		return (u16)len;

 	/* points to the payload of the request */
 	pos = &frame->u.probe_req.variable[0];

 	/* fill in our SSID IE */
 	left -= ssid_len + 2;
 	if (left < 0)
 		return 0;
 	*pos++ = WLAN_EID_SSID;
 	*pos++ = ssid_len;
 	if (ssid && ssid_len) { /* ssid_len may be == 0 even if ssid is valid */
 		memcpy(pos, ssid, ssid_len);
 		pos += ssid_len;
 	}

 	len += ssid_len + 2;

 	if (WARN_ON(left < ie_len))
 		return len;

 	if (ie && ie_len) {
 		memcpy(pos, ie, ie_len);
 		len += ie_len;
 	}

 	return (u16)len;
 }

 int iwl_mvm_scan_request(struct iwl_mvm *mvm,
 			 struct ieee80211_vif *vif,
 			 struct cfg80211_scan_request *req)
 {
 	struct iwl_host_cmd hcmd = {
 		.id = SCAN_REQUEST_CMD,
 		.len = { 0, },
 		.data = { mvm->scan_cmd, },
 		.flags = CMD_SYNC,
 		.dataflags = { IWL_HCMD_DFL_NOCOPY, },
 	};
 	struct iwl_scan_cmd *cmd = mvm->scan_cmd;
 	int ret;
 	u32 status;
 	int ssid_len = 0;
 	u8 *ssid = NULL;

 	lockdep_assert_held(&mvm->mutex);
 	BUG_ON(mvm->scan_cmd == NULL);

 	IWL_DEBUG_SCAN(mvm, "Handling mac80211 scan request\n");
 	mvm->scan_status = IWL_MVM_SCAN_OS;
 	memset(cmd, 0, sizeof(struct iwl_scan_cmd) +
 	       mvm->fw->ucode_capa.max_probe_length +
 	       (MAX_NUM_SCAN_CHANNELS * sizeof(struct iwl_scan_channel)));

 	cmd->channel_count = (u8)req->n_channels;
 	cmd->quiet_time = cpu_to_le16(IWL_ACTIVE_QUIET_TIME);
 	cmd->quiet_plcp_th = cpu_to_le16(IWL_PLCP_QUIET_THRESH);
 	cmd->rxchain_sel_flags = iwl_mvm_scan_rx_chain(mvm);
 	cmd->max_out_time = iwl_mvm_scan_max_out_time(vif);
 	cmd->suspend_time = iwl_mvm_scan_suspend_time(vif);
 	cmd->rxon_flags = iwl_mvm_scan_rxon_flags(req);
 	cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP |
 					MAC_FILTER_IN_BEACON);

 	if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
 		cmd->type = cpu_to_le32(SCAN_TYPE_DISCOVERY_FORCED);
 	else
 		cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);

 	/*
 	 * TODO: This is a WA due to a bug in the FW AUX framework that does not
 	 * properly handle time events that fail to be scheduled
 	 */
 	cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);

 	cmd->repeats = cpu_to_le32(1);

 	/*
 	 * If the user asked for passive scan, don't change to active scan if
 	 * you see any activity on the channel - remain passive.
 	 */
 	if (req->n_ssids > 0) {
 		cmd->passive2active = cpu_to_le16(1);
 		ssid = req->ssids[0].ssid;
 		ssid_len = req->ssids[0].ssid_len;
 	} else {
 		cmd->passive2active = 0;
 	}

 	iwl_mvm_scan_fill_ssids(cmd, req);

 	cmd->tx_cmd.tx_flags = cpu_to_le32(TX_CMD_FLG_SEQ_CTL |
 					   TX_CMD_FLG_BT_DIS);
 	cmd->tx_cmd.sta_id = mvm->aux_sta.sta_id;
 	cmd->tx_cmd.life_time = cpu_to_le32(TX_CMD_LIFE_TIME_INFINITE);
 	cmd->tx_cmd.rate_n_flags =
 			iwl_mvm_scan_rate_n_flags(mvm, req->channels[0]->band,
 						  req->no_cck);

 	cmd->tx_cmd.len =
 		cpu_to_le16(iwl_mvm_fill_probe_req(
 			    (struct ieee80211_mgmt *)cmd->data,
 			    vif->addr,
 			    req->n_ssids, ssid, ssid_len,
 			    req->ie, req->ie_len,
 			    mvm->fw->ucode_capa.max_probe_length));

 	iwl_mvm_scan_fill_channels(cmd, req);

 	cmd->len = cpu_to_le16(sizeof(struct iwl_scan_cmd) +
 		le16_to_cpu(cmd->tx_cmd.len) +
 		(cmd->channel_count * sizeof(struct iwl_scan_channel)));
 	hcmd.len[0] = le16_to_cpu(cmd->len);

 	status = SCAN_RESPONSE_OK;
 	ret = iwl_mvm_send_cmd_status(mvm, &hcmd, &status);
 	if (!ret && status == SCAN_RESPONSE_OK) {
 		IWL_DEBUG_SCAN(mvm, "Scan request was sent successfully\n");
 	} else {
 		/*
 		 * If the scan failed, it usually means that the FW was unable
 		 * to allocate the time events. Warn on it, but maybe we
 		 * should try to send the command again with different params.
 		 */
 		IWL_ERR(mvm, "Scan failed! status 0x%x ret %d\n",
 			status, ret);
 		mvm->scan_status = IWL_MVM_SCAN_NONE;
 		ret = -EIO;
 	}
 	return ret;
 }

 int iwl_mvm_rx_scan_response(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 			  struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_cmd_response *resp = (void *)pkt->data;

 	IWL_DEBUG_SCAN(mvm, "Scan response received. status 0x%x\n",
 		       le32_to_cpu(resp->status));
 	return 0;
 }

 int iwl_mvm_rx_scan_complete(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 			  struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_scan_complete_notif *notif = (void *)pkt->data;

 	IWL_DEBUG_SCAN(mvm, "Scan complete: status=0x%x scanned channels=%d\n",
 		       notif->status, notif->scanned_channels);

 	mvm->scan_status = IWL_MVM_SCAN_NONE;
 	ieee80211_scan_completed(mvm->hw, notif->status != SCAN_COMP_STATUS_OK);

 	return 0;
 }

 static bool iwl_mvm_scan_abort_notif(struct iwl_notif_wait_data *notif_wait,
 				     struct iwl_rx_packet *pkt, void *data)
 {
 	struct iwl_mvm *mvm =
 		container_of(notif_wait, struct iwl_mvm, notif_wait);
 	struct iwl_scan_complete_notif *notif;
 	u32 *resp;

 	switch (pkt->hdr.cmd) {
 	case SCAN_ABORT_CMD:
 		resp = (void *)pkt->data;
 		if (*resp == CAN_ABORT_STATUS) {
 			IWL_DEBUG_SCAN(mvm,
 				       "Scan can be aborted, wait until completion\n");
 			return false;
 		}

 		IWL_DEBUG_SCAN(mvm, "Scan cannot be aborted, exit now: %d\n",
 			       *resp);
 		return true;

 	case SCAN_COMPLETE_NOTIFICATION:
 		notif = (void *)pkt->data;
 		IWL_DEBUG_SCAN(mvm, "Scan aborted: status 0x%x\n",
 			       notif->status);
 		return true;

 	default:
 		WARN_ON(1);
 		return false;
 	};
 }

 void iwl_mvm_cancel_scan(struct iwl_mvm *mvm)
 {
 	struct iwl_notification_wait wait_scan_abort;
 	static const u8 scan_abort_notif[] = { SCAN_ABORT_CMD,
 					       SCAN_COMPLETE_NOTIFICATION };
 	int ret;

 	iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_abort,
 				   scan_abort_notif,
 				   ARRAY_SIZE(scan_abort_notif),
 				   iwl_mvm_scan_abort_notif, NULL);

 	ret = iwl_mvm_send_cmd_pdu(mvm, SCAN_ABORT_CMD, CMD_SYNC, 0, NULL);
 	if (ret) {
 		IWL_ERR(mvm, "Couldn't send SCAN_ABORT_CMD: %d\n", ret);
 		goto out_remove_notif;
 	}

 	ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_abort, 1 * HZ);
 	if (ret)
 		IWL_ERR(mvm, "%s - failed on timeout\n", __func__);

 	return;

 out_remove_notif:
 	iwl_remove_notification(&mvm->notif_wait, &wait_scan_abort);
 }
	/******************************************************************************
	*
	* This file is provided under a dual BSD/GPLv2 license. When using or
	* redistributing this file, you may do so under either license.
	*
	* GPL LICENSE SUMMARY
	*
	* Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of version 2 of the GNU General Public License as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
	* USA
	*
	* The full GNU General Public License is included in this distribution
	* in the file called COPYING.
	*
	* Contact Information:
	* Intel Linux Wireless <ilw@linux.intel.com>
	* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
	*
	* BSD LICENSE
	*
	* Copyright(c) 2012 - 2013 Intel Corporation. All rights reserved.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name Intel Corporation nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*****************************************************************************/

	#include <linux/etherdevice.h>
	#include <net/mac80211.h>

	#include "mvm.h"
	#include "iwl-eeprom-parse.h"
	#include "fw-api-scan.h"

	#define IWL_PLCP_QUIET_THRESH 1
	#define IWL_ACTIVE_QUIET_TIME 10

	static inline __le16 iwl_mvm_scan_rx_chain(struct iwl_mvm *mvm)
	{
	u16 rx_chain;
	u8 rx_ant = iwl_fw_valid_rx_ant(mvm->fw);

	rx_chain = rx_ant << PHY_RX_CHAIN_VALID_POS;
	rx_chain \|= rx_ant << PHY_RX_CHAIN_FORCE_MIMO_SEL_POS;
	rx_chain \|= rx_ant << PHY_RX_CHAIN_FORCE_SEL_POS;
	rx_chain \|= 0x1 << PHY_RX_CHAIN_DRIVER_FORCE_POS;
	return cpu_to_le16(rx_chain);
	}

	static inline __le32 iwl_mvm_scan_max_out_time(struct ieee80211_vif *vif)
	{
	if (vif->bss_conf.assoc)
	return cpu_to_le32(200 * 1024);
	else
	return 0;
	}

	static inline __le32 iwl_mvm_scan_suspend_time(struct ieee80211_vif *vif)
	{
	if (vif->bss_conf.assoc)
	return cpu_to_le32(vif->bss_conf.beacon_int);
	else
	return 0;
	}

	static inline __le32
	iwl_mvm_scan_rxon_flags(struct cfg80211_scan_request *req)
	{
	if (req->channels[0]->band == IEEE80211_BAND_2GHZ)
	return cpu_to_le32(PHY_BAND_24);
	else
	return cpu_to_le32(PHY_BAND_5);
	}

	static inline __le32
	iwl_mvm_scan_rate_n_flags(struct iwl_mvm *mvm, enum ieee80211_band band,
	bool no_cck)
	{
	u32 tx_ant;

	mvm->scan_last_antenna_idx =
	iwl_mvm_next_antenna(mvm, iwl_fw_valid_tx_ant(mvm->fw),
	mvm->scan_last_antenna_idx);
	tx_ant = BIT(mvm->scan_last_antenna_idx) << RATE_MCS_ANT_POS;

	if (band == IEEE80211_BAND_2GHZ && !no_cck)
	return cpu_to_le32(IWL_RATE_1M_PLCP \| RATE_MCS_CCK_MSK \|
	tx_ant);
	else
	return cpu_to_le32(IWL_RATE_6M_PLCP \| tx_ant);
	}

	/*
	* We insert the SSIDs in an inverted order, because the FW will
	* invert it back. The most prioritized SSID, which is first in the
	* request list, is not copied here, but inserted directly to the probe
	* request.
	*/
	static void iwl_mvm_scan_fill_ssids(struct iwl_scan_cmd *cmd,
	struct cfg80211_scan_request *req)
	{
	int fw_idx, req_idx;

	for (req_idx = req->n_ssids - 1, fw_idx = 0; req_idx > 0;
	req_idx--, fw_idx++) {
	cmd->direct_scan[fw_idx].id = WLAN_EID_SSID;
	cmd->direct_scan[fw_idx].len = req->ssids[req_idx].ssid_len;
	memcpy(cmd->direct_scan[fw_idx].ssid,
	req->ssids[req_idx].ssid,
	req->ssids[req_idx].ssid_len);
	}
	}

	/*
	* If req->n_ssids > 0, it means we should do an active scan.
	* In case of active scan w/o directed scan, we receive a zero-length SSID
	* just to notify that this scan is active and not passive.
	* In order to notify the FW of the number of SSIDs we wish to scan (including
	* the zero-length one), we need to set the corresponding bits in chan->type,
	* one for each SSID, and set the active bit (first).
	*/
	static u16 iwl_mvm_get_active_dwell(enum ieee80211_band band, int n_ssids)
	{
	if (band == IEEE80211_BAND_2GHZ)
	return 30 + 3 * (n_ssids + 1);
	return 20 + 2 * (n_ssids + 1);
	}

	static u16 iwl_mvm_get_passive_dwell(enum ieee80211_band band)
	{
	return band == IEEE80211_BAND_2GHZ ? 100 + 20 : 100 + 10;
	}

	static void iwl_mvm_scan_fill_channels(struct iwl_scan_cmd *cmd,
	struct cfg80211_scan_request *req)
	{
	u16 passive_dwell = iwl_mvm_get_passive_dwell(req->channels[0]->band);
	u16 active_dwell = iwl_mvm_get_active_dwell(req->channels[0]->band,
	req->n_ssids);
	struct iwl_scan_channel chan = (struct iwl_scan_channel )
	(cmd->data + le16_to_cpu(cmd->tx_cmd.len));
	int i;

	for (i = 0; i < cmd->channel_count; i++) {
	chan->channel = cpu_to_le16(req->channels[i]->hw_value);
	chan->type = cpu_to_le32(BIT(req->n_ssids) - 1);
	if (req->channels[i]->flags & IEEE80211_CHAN_PASSIVE_SCAN)
	chan->type &= cpu_to_le32(~SCAN_CHANNEL_TYPE_ACTIVE);
	chan->active_dwell = cpu_to_le16(active_dwell);
	chan->passive_dwell = cpu_to_le16(passive_dwell);
	chan->iteration_count = cpu_to_le16(1);
	chan++;
	}
	}

	/*
	* Fill in probe request with the following parameters:
	* TA is our vif HW address, which mac80211 ensures we have.
	* Packet is broadcasted, so this is both SA and DA.
	* The probe request IE is made out of two: first comes the most prioritized
	* SSID if a directed scan is requested. Second comes whatever extra
	* information was given to us as the scan request IE.
	*/
	static u16 iwl_mvm_fill_probe_req(struct ieee80211_mgmt frame, const u8 ta,
	int n_ssids, const u8 *ssid, int ssid_len,
	const u8 *ie, int ie_len,
	int left)
	{
	int len = 0;
	u8 *pos = NULL;

	/* Make sure there is enough space for the probe request,
	* two mandatory IEs and the data */
	left -= 24;
	if (left < 0)
	return 0;

	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
	eth_broadcast_addr(frame->da);
	memcpy(frame->sa, ta, ETH_ALEN);
	eth_broadcast_addr(frame->bssid);
	frame->seq_ctrl = 0;

	len += 24;

	/* for passive scans, no need to fill anything */
	if (n_ssids == 0)
	return (u16)len;

	/* points to the payload of the request */
	pos = &frame->u.probe_req.variable[0];

	/* fill in our SSID IE */
	left -= ssid_len + 2;
	if (left < 0)
	return 0;
	*pos++ = WLAN_EID_SSID;
	*pos++ = ssid_len;
	if (ssid && ssid_len) { /* ssid_len may be == 0 even if ssid is valid */
	memcpy(pos, ssid, ssid_len);
	pos += ssid_len;
	}

	len += ssid_len + 2;

	if (WARN_ON(left < ie_len))
	return len;

	if (ie && ie_len) {
	memcpy(pos, ie, ie_len);
	len += ie_len;
	}

	return (u16)len;
	}

	int iwl_mvm_scan_request(struct iwl_mvm *mvm,
	struct ieee80211_vif *vif,
	struct cfg80211_scan_request *req)
	{
	struct iwl_host_cmd hcmd = {
	.id = SCAN_REQUEST_CMD,
	.len = { 0, },
	.data = { mvm->scan_cmd, },
	.flags = CMD_SYNC,
	.dataflags = { IWL_HCMD_DFL_NOCOPY, },
	};
	struct iwl_scan_cmd *cmd = mvm->scan_cmd;
	int ret;
	u32 status;
	int ssid_len = 0;
	u8 *ssid = NULL;

	lockdep_assert_held(&mvm->mutex);
	BUG_ON(mvm->scan_cmd == NULL);

	IWL_DEBUG_SCAN(mvm, "Handling mac80211 scan request\n");
	mvm->scan_status = IWL_MVM_SCAN_OS;
	memset(cmd, 0, sizeof(struct iwl_scan_cmd) +
	mvm->fw->ucode_capa.max_probe_length +
	(MAX_NUM_SCAN_CHANNELS * sizeof(struct iwl_scan_channel)));

	cmd->channel_count = (u8)req->n_channels;
	cmd->quiet_time = cpu_to_le16(IWL_ACTIVE_QUIET_TIME);
	cmd->quiet_plcp_th = cpu_to_le16(IWL_PLCP_QUIET_THRESH);
	cmd->rxchain_sel_flags = iwl_mvm_scan_rx_chain(mvm);
	cmd->max_out_time = iwl_mvm_scan_max_out_time(vif);
	cmd->suspend_time = iwl_mvm_scan_suspend_time(vif);
	cmd->rxon_flags = iwl_mvm_scan_rxon_flags(req);
	cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP \|
	MAC_FILTER_IN_BEACON);

	if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
	cmd->type = cpu_to_le32(SCAN_TYPE_DISCOVERY_FORCED);
	else
	cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);

	/*
	* TODO: This is a WA due to a bug in the FW AUX framework that does not
	* properly handle time events that fail to be scheduled
	*/
	cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);

	cmd->repeats = cpu_to_le32(1);

	/*
	* If the user asked for passive scan, don't change to active scan if
	* you see any activity on the channel - remain passive.
	*/
	if (req->n_ssids > 0) {
	cmd->passive2active = cpu_to_le16(1);
	ssid = req->ssids[0].ssid;
	ssid_len = req->ssids[0].ssid_len;
	} else {
	cmd->passive2active = 0;
	}

	iwl_mvm_scan_fill_ssids(cmd, req);

	cmd->tx_cmd.tx_flags = cpu_to_le32(TX_CMD_FLG_SEQ_CTL \|
	TX_CMD_FLG_BT_DIS);
	cmd->tx_cmd.sta_id = mvm->aux_sta.sta_id;
	cmd->tx_cmd.life_time = cpu_to_le32(TX_CMD_LIFE_TIME_INFINITE);
	cmd->tx_cmd.rate_n_flags =
	iwl_mvm_scan_rate_n_flags(mvm, req->channels[0]->band,
	req->no_cck);

	cmd->tx_cmd.len =
	cpu_to_le16(iwl_mvm_fill_probe_req(
	(struct ieee80211_mgmt *)cmd->data,
	vif->addr,
	req->n_ssids, ssid, ssid_len,
	req->ie, req->ie_len,
	mvm->fw->ucode_capa.max_probe_length));

	iwl_mvm_scan_fill_channels(cmd, req);

	cmd->len = cpu_to_le16(sizeof(struct iwl_scan_cmd) +
	le16_to_cpu(cmd->tx_cmd.len) +
	(cmd->channel_count * sizeof(struct iwl_scan_channel)));
	hcmd.len[0] = le16_to_cpu(cmd->len);

	status = SCAN_RESPONSE_OK;
	ret = iwl_mvm_send_cmd_status(mvm, &hcmd, &status);
	if (!ret && status == SCAN_RESPONSE_OK) {
	IWL_DEBUG_SCAN(mvm, "Scan request was sent successfully\n");
	} else {
	/*
	* If the scan failed, it usually means that the FW was unable
	* to allocate the time events. Warn on it, but maybe we
	* should try to send the command again with different params.
	*/
	IWL_ERR(mvm, "Scan failed! status 0x%x ret %d\n",
	status, ret);
	mvm->scan_status = IWL_MVM_SCAN_NONE;
	ret = -EIO;
	}
	return ret;
	}

	int iwl_mvm_rx_scan_response(struct iwl_mvm mvm, struct iwl_rx_cmd_buffer rxb,
	struct iwl_device_cmd *cmd)
	{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_cmd_response resp = (void )pkt->data;

	IWL_DEBUG_SCAN(mvm, "Scan response received. status 0x%x\n",
	le32_to_cpu(resp->status));
	return 0;
	}

	int iwl_mvm_rx_scan_complete(struct iwl_mvm mvm, struct iwl_rx_cmd_buffer rxb,
	struct iwl_device_cmd *cmd)
	{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_scan_complete_notif notif = (void )pkt->data;

	IWL_DEBUG_SCAN(mvm, "Scan complete: status=0x%x scanned channels=%d\n",
	notif->status, notif->scanned_channels);

	mvm->scan_status = IWL_MVM_SCAN_NONE;
	ieee80211_scan_completed(mvm->hw, notif->status != SCAN_COMP_STATUS_OK);

	return 0;
	}

	static bool iwl_mvm_scan_abort_notif(struct iwl_notif_wait_data *notif_wait,
	struct iwl_rx_packet pkt, void data)
	{
	struct iwl_mvm *mvm =
	container_of(notif_wait, struct iwl_mvm, notif_wait);
	struct iwl_scan_complete_notif *notif;
	u32 *resp;

	switch (pkt->hdr.cmd) {
	case SCAN_ABORT_CMD:
	resp = (void *)pkt->data;
	if (*resp == CAN_ABORT_STATUS) {
	IWL_DEBUG_SCAN(mvm,
	"Scan can be aborted, wait until completion\n");
	return false;
	}

	IWL_DEBUG_SCAN(mvm, "Scan cannot be aborted, exit now: %d\n",
	*resp);
	return true;

	case SCAN_COMPLETE_NOTIFICATION:
	notif = (void *)pkt->data;
	IWL_DEBUG_SCAN(mvm, "Scan aborted: status 0x%x\n",
	notif->status);
	return true;

	default:
	WARN_ON(1);
	return false;
	};
	}

	void iwl_mvm_cancel_scan(struct iwl_mvm *mvm)
	{
	struct iwl_notification_wait wait_scan_abort;
	static const u8 scan_abort_notif[] = { SCAN_ABORT_CMD,
	SCAN_COMPLETE_NOTIFICATION };
	int ret;

	iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_abort,
	scan_abort_notif,
	ARRAY_SIZE(scan_abort_notif),
	iwl_mvm_scan_abort_notif, NULL);

	ret = iwl_mvm_send_cmd_pdu(mvm, SCAN_ABORT_CMD, CMD_SYNC, 0, NULL);
	if (ret) {
	IWL_ERR(mvm, "Couldn't send SCAN_ABORT_CMD: %d\n", ret);
	goto out_remove_notif;
	}

	ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_abort, 1 * HZ);
	if (ret)
	IWL_ERR(mvm, "%s - failed on timeout\n", __func__);

	return;

	out_remove_notif:
	iwl_remove_notification(&mvm->notif_wait, &wait_scan_abort);
	}