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/*-
* Based on BSD-licensed source modules in the Linux iwlwifi driver,
* which were used as the reference documentation for this implementation.
*
* Driver version we are currently based off of is
* Linux 4.7.3 (tag id d7f6728f57e3ecbb7ef34eb7d9f564d514775d75)
*
***********************************************************************
*
*
* 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) 2015 - 2016 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
* Copyright(c) 2015 - 2016 Intel Deutschland 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.
*
*****************************************************************************/
#ifndef __IF_IWM_STA_H__
#define __IF_IWM_STA_H__
/**
* DOC: station table - introduction
*
* The station table is a list of data structure that reprensent the stations.
* In STA/P2P client mode, the driver will hold one station for the AP/ GO.
* In GO/AP mode, the driver will have as many stations as associated clients.
* All these stations are reflected in the fw's station table. The driver
* keeps the fw's station table up to date with the ADD_STA command. Stations
* can be removed by the REMOVE_STA command.
*
* All the data related to a station is held in the structure %iwl_sta
* which is embed in the mac80211's %ieee80211_sta (in the drv_priv) area.
* This data includes the index of the station in the fw, per tid information
* (sequence numbers, Block-ack state machine, etc...). The stations are
* created and deleted by the %sta_state callback from %ieee80211_ops.
*
* The driver holds a map: %fw_id_to_mac_id that allows to fetch a
* %ieee80211_sta (and the %iwl_sta embedded into it) based on a fw
* station index. That way, the driver is able to get the tid related data in
* O(1) in time sensitive paths (Tx / Tx response / BA notification). These
* paths are triggered by the fw, and the driver needs to get a pointer to the
* %ieee80211 structure. This map helps to get that pointer quickly.
*/
/**
* DOC: station table - locking
*
* As stated before, the station is created / deleted by mac80211's %sta_state
* callback from %ieee80211_ops which can sleep. The next paragraph explains
* the locking of a single stations, the next ones relates to the station
* table.
*
* The station holds the sequence number per tid. So this data needs to be
* accessed in the Tx path (which is softIRQ). It also holds the Block-Ack
* information (the state machine / and the logic that checks if the queues
* were drained), so it also needs to be accessible from the Tx response flow.
* In short, the station needs to be access from sleepable context as well as
* from tasklets, so the station itself needs a spinlock.
*
* The writers of %fw_id_to_mac_id map are serialized by the global mutex of
* the mvm op_mode. This is possible since %sta_state can sleep.
* The pointers in this map are RCU protected, hence we won't replace the
* station while we have Tx / Tx response / BA notification running.
*
* If a station is deleted while it still has packets in its A-MPDU queues,
* then the reclaim flow will notice that there is no station in the map for
* sta_id and it will dump the responses.
*/
/**
* DOC: station table - internal stations
*
* The FW needs a few internal stations that are not reflected in
* mac80211, such as broadcast station in AP / GO mode, or AUX sta for
* scanning and P2P device (during the GO negotiation).
* For these kind of stations we have %iwl_int_sta struct which holds the
* data relevant for them from both %iwl_sta and %ieee80211_sta.
* Usually the data for these stations is static, so no locking is required,
* and no TID data as this is also not needed.
* One thing to note, is that these stations have an ID in the fw, but not
* in mac80211. In order to "reserve" them a sta_id in %fw_id_to_mac_id
* we fill ERR_PTR(EINVAL) in this mapping and all other dereferencing of
* pointers from this mapping need to check that the value is not error
* or NULL.
*
* Currently there is only one auxiliary station for scanning, initialized
* on init.
*/
/**
* DOC: station table - AP Station in STA mode
*
* %iwl_vif includes the index of the AP station in the fw's STA table:
* %ap_sta_id. To get the point to the corresponding %ieee80211_sta,
* &fw_id_to_mac_id can be used. Due to the way the fw works, we must not remove
* the AP station from the fw before setting the MAC context as unassociated.
* Hence, %fw_id_to_mac_id[%ap_sta_id] will be NULLed when the AP station is
* removed by mac80211, but the station won't be removed in the fw until the
* VIF is set as unassociated. Then, %ap_sta_id will be invalidated.
*/
/**
* DOC: station table - Drain vs. Flush
*
* Flush means that all the frames in the SCD queue are dumped regardless the
* station to which they were sent. We do that when we disassociate and before
* we remove the STA of the AP. The flush can be done synchronously against the
* fw.
* Drain means that the fw will drop all the frames sent to a specific station.
* This is useful when a client (if we are IBSS / GO or AP) disassociates. In
* that case, we need to drain all the frames for that client from the AC queues
* that are shared with the other clients. Only then, we can remove the STA in
* the fw. In order to do so, we track the non-AMPDU packets for each station.
* If mac80211 removes a STA and if it still has non-AMPDU packets pending in
* the queues, we mark this station as %EBUSY in %fw_id_to_mac_id, and drop all
* the frames for this STA (%iwl_rm_sta). When the last frame is dropped
* (we know about it with its Tx response), we remove the station in fw and set
* it as %NULL in %fw_id_to_mac_id: this is the purpose of
* %iwl_sta_drained_wk.
*/
/**
* DOC: station table - fw restart
*
* When the fw asserts, or we have any other issue that requires to reset the
* driver, we require mac80211 to reconfigure the driver. Since the private
* data of the stations is embed in mac80211's %ieee80211_sta, that data will
* not be zeroed and needs to be reinitialized manually.
* %IWL_STATUS_IN_HW_RESTART is set during restart and that will hint us
* that we must not allocate a new sta_id but reuse the previous one. This
* means that the stations being re-added after the reset will have the same
* place in the fw as before the reset. We do need to zero the %fw_id_to_mac_id
* map, since the stations aren't in the fw any more. Internal stations that
* are not added by mac80211 will be re-added in the init flow that is called
* after the restart: mac80211 call's %iwl_mac_start which calls to
* %iwl_up.
*/
/**
* Send the STA info to the FW.
*
* @sc: the iwm_softc* to use
* @sta: the STA
* @update: this is true if the FW is being updated about a STA it already knows
* about. Otherwise (if this is a new STA), this should be false.
* @flags: if update==true, this marks what is being changed via ORs of values
* from enum iwm_sta_modify_flag. Otherwise, this is ignored.
*/
extern int iwm_sta_send_to_fw(struct iwm_softc *sc, struct iwm_node *in,
boolean_t update);
extern int iwm_add_sta(struct iwm_softc *sc, struct iwm_node *in);
extern int iwm_update_sta(struct iwm_softc *sc, struct iwm_node *in);
extern int iwm_rm_sta(struct iwm_softc *sc, struct ieee80211vap *vap,
boolean_t is_assoc);
extern int iwm_rm_sta_id(struct iwm_softc *sc, struct ieee80211vap *vap);
extern int iwm_add_aux_sta(struct iwm_softc *sc);
extern void iwm_del_aux_sta(struct iwm_softc *sc);
extern int iwm_drain_sta(struct iwm_softc *sc, struct iwm_vap *ivp,
boolean_t drain);
#endif /* __IF_IWM_STA_H__ */
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