drivers/net/wireless/intel/iwlwifi/mvm/phy-ctxt.c - arm/linux - 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 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
  * Copyright(c) 2017           Intel Deutschland GmbH
  *
  * 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 <linuxwifi@intel.com>
  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  *
  * BSD LICENSE
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
  * 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 <net/mac80211.h>
 #include "fw-api.h"
 #include "mvm.h"

 /* Maps the driver specific channel width definition to the fw values */
 u8 iwl_mvm_get_channel_width(struct cfg80211_chan_def *chandef)
 {
 	switch (chandef->width) {
 	case NL80211_CHAN_WIDTH_20_NOHT:
 	case NL80211_CHAN_WIDTH_20:
 		return PHY_VHT_CHANNEL_MODE20;
 	case NL80211_CHAN_WIDTH_40:
 		return PHY_VHT_CHANNEL_MODE40;
 	case NL80211_CHAN_WIDTH_80:
 		return PHY_VHT_CHANNEL_MODE80;
 	case NL80211_CHAN_WIDTH_160:
 		return PHY_VHT_CHANNEL_MODE160;
 	default:
 		WARN(1, "Invalid channel width=%u", chandef->width);
 		return PHY_VHT_CHANNEL_MODE20;
 	}
 }

 /*
  * Maps the driver specific control channel position (relative to the center
  * freq) definitions to the the fw values
  */
 u8 iwl_mvm_get_ctrl_pos(struct cfg80211_chan_def *chandef)
 {
 	switch (chandef->chan->center_freq - chandef->center_freq1) {
 	case -70:
 		return PHY_VHT_CTRL_POS_4_BELOW;
 	case -50:
 		return PHY_VHT_CTRL_POS_3_BELOW;
 	case -30:
 		return PHY_VHT_CTRL_POS_2_BELOW;
 	case -10:
 		return PHY_VHT_CTRL_POS_1_BELOW;
 	case  10:
 		return PHY_VHT_CTRL_POS_1_ABOVE;
 	case  30:
 		return PHY_VHT_CTRL_POS_2_ABOVE;
 	case  50:
 		return PHY_VHT_CTRL_POS_3_ABOVE;
 	case  70:
 		return PHY_VHT_CTRL_POS_4_ABOVE;
 	default:
 		WARN(1, "Invalid channel definition");
 	case 0:
 		/*
 		 * The FW is expected to check the control channel position only
 		 * when in HT/VHT and the channel width is not 20MHz. Return
 		 * this value as the default one.
 		 */
 		return PHY_VHT_CTRL_POS_1_BELOW;
 	}
 }

 /*
  * Construct the generic fields of the PHY context command
  */
 static void iwl_mvm_phy_ctxt_cmd_hdr(struct iwl_mvm_phy_ctxt *ctxt,
 				     struct iwl_phy_context_cmd *cmd,
 				     u32 action, u32 apply_time)
 {
 	memset(cmd, 0, sizeof(struct iwl_phy_context_cmd));

 	cmd->id_and_color = cpu_to_le32(FW_CMD_ID_AND_COLOR(ctxt->id,
 							    ctxt->color));
 	cmd->action = cpu_to_le32(action);
 	cmd->apply_time = cpu_to_le32(apply_time);
 }

 /*
  * Add the phy configuration to the PHY context command
  */
 static void iwl_mvm_phy_ctxt_cmd_data(struct iwl_mvm *mvm,
 				      struct iwl_phy_context_cmd *cmd,
 				      struct cfg80211_chan_def *chandef,
 				      u8 chains_static, u8 chains_dynamic)
 {
 	u8 active_cnt, idle_cnt;

 	/* Set the channel info data */
 	cmd->ci.band = (chandef->chan->band == NL80211_BAND_2GHZ ?
 	      PHY_BAND_24 : PHY_BAND_5);

 	cmd->ci.channel = chandef->chan->hw_value;
 	cmd->ci.width = iwl_mvm_get_channel_width(chandef);
 	cmd->ci.ctrl_pos = iwl_mvm_get_ctrl_pos(chandef);

 	/* Set rx the chains */
 	idle_cnt = chains_static;
 	active_cnt = chains_dynamic;

 	/* In scenarios where we only ever use a single-stream rates,
 	 * i.e. legacy 11b/g/a associations, single-stream APs or even
 	 * static SMPS, enable both chains to get diversity, improving
 	 * the case where we're far enough from the AP that attenuation
 	 * between the two antennas is sufficiently different to impact
 	 * performance.
 	 */
 	if (active_cnt == 1 && iwl_mvm_rx_diversity_allowed(mvm)) {
 		idle_cnt = 2;
 		active_cnt = 2;
 	}

 	cmd->rxchain_info = cpu_to_le32(iwl_mvm_get_valid_rx_ant(mvm) <<
 					PHY_RX_CHAIN_VALID_POS);
 	cmd->rxchain_info |= cpu_to_le32(idle_cnt << PHY_RX_CHAIN_CNT_POS);
 	cmd->rxchain_info |= cpu_to_le32(active_cnt <<
 					 PHY_RX_CHAIN_MIMO_CNT_POS);
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 	if (unlikely(mvm->dbgfs_rx_phyinfo))
 		cmd->rxchain_info = cpu_to_le32(mvm->dbgfs_rx_phyinfo);
 #endif

 	cmd->txchain_info = cpu_to_le32(iwl_mvm_get_valid_tx_ant(mvm));
 }

 /*
  * Send a command to apply the current phy configuration. The command is send
  * only if something in the configuration changed: in case that this is the
  * first time that the phy configuration is applied or in case that the phy
  * configuration changed from the previous apply.
  */
 static int iwl_mvm_phy_ctxt_apply(struct iwl_mvm *mvm,
 				  struct iwl_mvm_phy_ctxt *ctxt,
 				  struct cfg80211_chan_def *chandef,
 				  u8 chains_static, u8 chains_dynamic,
 				  u32 action, u32 apply_time)
 {
 	struct iwl_phy_context_cmd cmd;
 	int ret;

 	/* Set the command header fields */
 	iwl_mvm_phy_ctxt_cmd_hdr(ctxt, &cmd, action, apply_time);

 	/* Set the command data */
 	iwl_mvm_phy_ctxt_cmd_data(mvm, &cmd, chandef,
 				  chains_static, chains_dynamic);

 	ret = iwl_mvm_send_cmd_pdu(mvm, PHY_CONTEXT_CMD, 0,
 				   sizeof(struct iwl_phy_context_cmd),
 				   &cmd);
 	if (ret)
 		IWL_ERR(mvm, "PHY ctxt cmd error. ret=%d\n", ret);
 	return ret;
 }

 /*
  * Send a command to add a PHY context based on the current HW configuration.
  */
 int iwl_mvm_phy_ctxt_add(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt,
 			 struct cfg80211_chan_def *chandef,
 			 u8 chains_static, u8 chains_dynamic)
 {
 	WARN_ON(!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) &&
 		ctxt->ref);
 	lockdep_assert_held(&mvm->mutex);

 	ctxt->channel = chandef->chan;

 	return iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
 				      chains_static, chains_dynamic,
 				      FW_CTXT_ACTION_ADD, 0);
 }

 /*
  * Update the number of references to the given PHY context. This is valid only
  * in case the PHY context was already created, i.e., its reference count > 0.
  */
 void iwl_mvm_phy_ctxt_ref(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt)
 {
 	lockdep_assert_held(&mvm->mutex);
 	ctxt->ref++;
 }

 /*
  * Send a command to modify the PHY context based on the current HW
  * configuration. Note that the function does not check that the configuration
  * changed.
  */
 int iwl_mvm_phy_ctxt_changed(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt,
 			     struct cfg80211_chan_def *chandef,
 			     u8 chains_static, u8 chains_dynamic)
 {
 	enum iwl_ctxt_action action = FW_CTXT_ACTION_MODIFY;

 	lockdep_assert_held(&mvm->mutex);

 	if (fw_has_capa(&mvm->fw->ucode_capa,
 			IWL_UCODE_TLV_CAPA_BINDING_CDB_SUPPORT) &&
 	    ctxt->channel->band != chandef->chan->band) {
 		int ret;

 		/* ... remove it here ...*/
 		ret = iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
 					     chains_static, chains_dynamic,
 					     FW_CTXT_ACTION_REMOVE, 0);
 		if (ret)
 			return ret;

 		/* ... and proceed to add it again */
 		action = FW_CTXT_ACTION_ADD;
 	}

 	ctxt->channel = chandef->chan;
 	return iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
 				      chains_static, chains_dynamic,
 				      action, 0);
 }

 void iwl_mvm_phy_ctxt_unref(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt)
 {
 	lockdep_assert_held(&mvm->mutex);

 	if (WARN_ON_ONCE(!ctxt))
 		return;

 	ctxt->ref--;
 }

 static void iwl_mvm_binding_iterator(void *_data, u8 *mac,
 				     struct ieee80211_vif *vif)
 {
 	unsigned long *data = _data;
 	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

 	if (!mvmvif->phy_ctxt)
 		return;

 	if (vif->type == NL80211_IFTYPE_STATION ||
 	    vif->type == NL80211_IFTYPE_AP)
 		__set_bit(mvmvif->phy_ctxt->id, data);
 }

 int iwl_mvm_phy_ctx_count(struct iwl_mvm *mvm)
 {
 	unsigned long phy_ctxt_counter = 0;

 	ieee80211_iterate_active_interfaces_atomic(mvm->hw,
 						   IEEE80211_IFACE_ITER_NORMAL,
 						   iwl_mvm_binding_iterator,
 						   &phy_ctxt_counter);

 	return hweight8(phy_ctxt_counter);
 }
	/******************************************************************************
	*
	* 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 - 2014 Intel Corporation. All rights reserved.
	* Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
	* Copyright(c) 2017 Intel Deutschland GmbH
	*
	* 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 <linuxwifi@intel.com>
	* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
	*
	* BSD LICENSE
	*
	* Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
	* Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
	* 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 <net/mac80211.h>
	#include "fw-api.h"
	#include "mvm.h"

	/* Maps the driver specific channel width definition to the fw values */
	u8 iwl_mvm_get_channel_width(struct cfg80211_chan_def *chandef)
	{
	switch (chandef->width) {
	case NL80211_CHAN_WIDTH_20_NOHT:
	case NL80211_CHAN_WIDTH_20:
	return PHY_VHT_CHANNEL_MODE20;
	case NL80211_CHAN_WIDTH_40:
	return PHY_VHT_CHANNEL_MODE40;
	case NL80211_CHAN_WIDTH_80:
	return PHY_VHT_CHANNEL_MODE80;
	case NL80211_CHAN_WIDTH_160:
	return PHY_VHT_CHANNEL_MODE160;
	default:
	WARN(1, "Invalid channel width=%u", chandef->width);
	return PHY_VHT_CHANNEL_MODE20;
	}
	}

	/*
	* Maps the driver specific control channel position (relative to the center
	* freq) definitions to the the fw values
	*/
	u8 iwl_mvm_get_ctrl_pos(struct cfg80211_chan_def *chandef)
	{
	switch (chandef->chan->center_freq - chandef->center_freq1) {
	case -70:
	return PHY_VHT_CTRL_POS_4_BELOW;
	case -50:
	return PHY_VHT_CTRL_POS_3_BELOW;
	case -30:
	return PHY_VHT_CTRL_POS_2_BELOW;
	case -10:
	return PHY_VHT_CTRL_POS_1_BELOW;
	case 10:
	return PHY_VHT_CTRL_POS_1_ABOVE;
	case 30:
	return PHY_VHT_CTRL_POS_2_ABOVE;
	case 50:
	return PHY_VHT_CTRL_POS_3_ABOVE;
	case 70:
	return PHY_VHT_CTRL_POS_4_ABOVE;
	default:
	WARN(1, "Invalid channel definition");
	case 0:
	/*
	* The FW is expected to check the control channel position only
	* when in HT/VHT and the channel width is not 20MHz. Return
	* this value as the default one.
	*/
	return PHY_VHT_CTRL_POS_1_BELOW;
	}
	}

	/*
	* Construct the generic fields of the PHY context command
	*/
	static void iwl_mvm_phy_ctxt_cmd_hdr(struct iwl_mvm_phy_ctxt *ctxt,
	struct iwl_phy_context_cmd *cmd,
	u32 action, u32 apply_time)
	{
	memset(cmd, 0, sizeof(struct iwl_phy_context_cmd));

	cmd->id_and_color = cpu_to_le32(FW_CMD_ID_AND_COLOR(ctxt->id,
	ctxt->color));
	cmd->action = cpu_to_le32(action);
	cmd->apply_time = cpu_to_le32(apply_time);
	}

	/*
	* Add the phy configuration to the PHY context command
	*/
	static void iwl_mvm_phy_ctxt_cmd_data(struct iwl_mvm *mvm,
	struct iwl_phy_context_cmd *cmd,
	struct cfg80211_chan_def *chandef,
	u8 chains_static, u8 chains_dynamic)
	{
	u8 active_cnt, idle_cnt;

	/* Set the channel info data */
	cmd->ci.band = (chandef->chan->band == NL80211_BAND_2GHZ ?
	PHY_BAND_24 : PHY_BAND_5);

	cmd->ci.channel = chandef->chan->hw_value;
	cmd->ci.width = iwl_mvm_get_channel_width(chandef);
	cmd->ci.ctrl_pos = iwl_mvm_get_ctrl_pos(chandef);

	/* Set rx the chains */
	idle_cnt = chains_static;
	active_cnt = chains_dynamic;

	/* In scenarios where we only ever use a single-stream rates,
	* i.e. legacy 11b/g/a associations, single-stream APs or even
	* static SMPS, enable both chains to get diversity, improving
	* the case where we're far enough from the AP that attenuation
	* between the two antennas is sufficiently different to impact
	* performance.
	*/
	if (active_cnt == 1 && iwl_mvm_rx_diversity_allowed(mvm)) {
	idle_cnt = 2;
	active_cnt = 2;
	}

	cmd->rxchain_info = cpu_to_le32(iwl_mvm_get_valid_rx_ant(mvm) <<
	PHY_RX_CHAIN_VALID_POS);
	cmd->rxchain_info \|= cpu_to_le32(idle_cnt << PHY_RX_CHAIN_CNT_POS);
	cmd->rxchain_info \|= cpu_to_le32(active_cnt <<
	PHY_RX_CHAIN_MIMO_CNT_POS);
	#ifdef CONFIG_IWLWIFI_DEBUGFS
	if (unlikely(mvm->dbgfs_rx_phyinfo))
	cmd->rxchain_info = cpu_to_le32(mvm->dbgfs_rx_phyinfo);
	#endif

	cmd->txchain_info = cpu_to_le32(iwl_mvm_get_valid_tx_ant(mvm));
	}

	/*
	* Send a command to apply the current phy configuration. The command is send
	* only if something in the configuration changed: in case that this is the
	* first time that the phy configuration is applied or in case that the phy
	* configuration changed from the previous apply.
	*/
	static int iwl_mvm_phy_ctxt_apply(struct iwl_mvm *mvm,
	struct iwl_mvm_phy_ctxt *ctxt,
	struct cfg80211_chan_def *chandef,
	u8 chains_static, u8 chains_dynamic,
	u32 action, u32 apply_time)
	{
	struct iwl_phy_context_cmd cmd;
	int ret;

	/* Set the command header fields */
	iwl_mvm_phy_ctxt_cmd_hdr(ctxt, &cmd, action, apply_time);

	/* Set the command data */
	iwl_mvm_phy_ctxt_cmd_data(mvm, &cmd, chandef,
	chains_static, chains_dynamic);

	ret = iwl_mvm_send_cmd_pdu(mvm, PHY_CONTEXT_CMD, 0,
	sizeof(struct iwl_phy_context_cmd),
	&cmd);
	if (ret)
	IWL_ERR(mvm, "PHY ctxt cmd error. ret=%d\n", ret);
	return ret;
	}

	/*
	* Send a command to add a PHY context based on the current HW configuration.
	*/
	int iwl_mvm_phy_ctxt_add(struct iwl_mvm mvm, struct iwl_mvm_phy_ctxt ctxt,
	struct cfg80211_chan_def *chandef,
	u8 chains_static, u8 chains_dynamic)
	{
	WARN_ON(!test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) &&
	ctxt->ref);
	lockdep_assert_held(&mvm->mutex);

	ctxt->channel = chandef->chan;

	return iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
	chains_static, chains_dynamic,
	FW_CTXT_ACTION_ADD, 0);
	}

	/*
	* Update the number of references to the given PHY context. This is valid only
	* in case the PHY context was already created, i.e., its reference count > 0.
	*/
	void iwl_mvm_phy_ctxt_ref(struct iwl_mvm mvm, struct iwl_mvm_phy_ctxt ctxt)
	{
	lockdep_assert_held(&mvm->mutex);
	ctxt->ref++;
	}

	/*
	* Send a command to modify the PHY context based on the current HW
	* configuration. Note that the function does not check that the configuration
	* changed.
	*/
	int iwl_mvm_phy_ctxt_changed(struct iwl_mvm mvm, struct iwl_mvm_phy_ctxt ctxt,
	struct cfg80211_chan_def *chandef,
	u8 chains_static, u8 chains_dynamic)
	{
	enum iwl_ctxt_action action = FW_CTXT_ACTION_MODIFY;

	lockdep_assert_held(&mvm->mutex);

	if (fw_has_capa(&mvm->fw->ucode_capa,
	IWL_UCODE_TLV_CAPA_BINDING_CDB_SUPPORT) &&
	ctxt->channel->band != chandef->chan->band) {
	int ret;

	/* ... remove it here ...*/
	ret = iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
	chains_static, chains_dynamic,
	FW_CTXT_ACTION_REMOVE, 0);
	if (ret)
	return ret;

	/* ... and proceed to add it again */
	action = FW_CTXT_ACTION_ADD;
	}

	ctxt->channel = chandef->chan;
	return iwl_mvm_phy_ctxt_apply(mvm, ctxt, chandef,
	chains_static, chains_dynamic,
	action, 0);
	}

	void iwl_mvm_phy_ctxt_unref(struct iwl_mvm mvm, struct iwl_mvm_phy_ctxt ctxt)
	{
	lockdep_assert_held(&mvm->mutex);

	if (WARN_ON_ONCE(!ctxt))
	return;

	ctxt->ref--;
	}

	static void iwl_mvm_binding_iterator(void _data, u8 mac,
	struct ieee80211_vif *vif)
	{
	unsigned long *data = _data;
	struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);

	if (!mvmvif->phy_ctxt)
	return;

	if (vif->type == NL80211_IFTYPE_STATION \|\|
	vif->type == NL80211_IFTYPE_AP)
	__set_bit(mvmvif->phy_ctxt->id, data);
	}

	int iwl_mvm_phy_ctx_count(struct iwl_mvm *mvm)
	{
	unsigned long phy_ctxt_counter = 0;

	ieee80211_iterate_active_interfaces_atomic(mvm->hw,
	IEEE80211_IFACE_ITER_NORMAL,
	iwl_mvm_binding_iterator,
	&phy_ctxt_counter);

	return hweight8(phy_ctxt_counter);
	}