1 /*-
2 * Based on BSD-licensed source modules in the Linux iwlwifi driver,
3 * which were used as the reference documentation for this implementation.
4 *
5 * Driver version we are currently based off of is
6 * Linux 4.7.3 (tag id d7f6728f57e3ecbb7ef34eb7d9f564d514775d75)
7 *
8 ***********************************************************************
9 *
10 *
11 * This file is provided under a dual BSD/GPLv2 license. When using or
12 * redistributing this file, you may do so under either license.
13 *
14 * GPL LICENSE SUMMARY
15 *
16 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
17 * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
18 * Copyright(c) 2015 - 2016 Intel Deutschland GmbH
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of version 2 of the GNU General Public License as
22 * published by the Free Software Foundation.
23 *
24 * This program is distributed in the hope that it will be useful, but
25 * WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
27 * General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with this program; if not, write to the Free Software
31 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
32 * USA
33 *
34 * The full GNU General Public License is included in this distribution
35 * in the file called COPYING.
36 *
37 * Contact Information:
38 * Intel Linux Wireless <linuxwifi@intel.com>
39 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
40 *
41 * BSD LICENSE
42 *
43 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
44 * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
45 * Copyright(c) 2015 - 2016 Intel Deutschland GmbH
46 * All rights reserved.
47 *
48 * Redistribution and use in source and binary forms, with or without
49 * modification, are permitted provided that the following conditions
50 * are met:
51 *
52 * * Redistributions of source code must retain the above copyright
53 * notice, this list of conditions and the following disclaimer.
54 * * Redistributions in binary form must reproduce the above copyright
55 * notice, this list of conditions and the following disclaimer in
56 * the documentation and/or other materials provided with the
57 * distribution.
58 * * Neither the name Intel Corporation nor the names of its
59 * contributors may be used to endorse or promote products derived
60 * from this software without specific prior written permission.
61 *
62 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
63 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
64 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
65 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
66 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
67 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
68 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
69 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
70 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
71 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
72 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
73 *
74 *****************************************************************************/
75
76 /* $FreeBSD$ */
77
78 #ifndef __IF_IWM_STA_H__
79 #define __IF_IWM_STA_H__
80
81 /**
82 * DOC: station table - introduction
83 *
84 * The station table is a list of data structure that reprensent the stations.
85 * In STA/P2P client mode, the driver will hold one station for the AP/ GO.
86 * In GO/AP mode, the driver will have as many stations as associated clients.
87 * All these stations are reflected in the fw's station table. The driver
88 * keeps the fw's station table up to date with the ADD_STA command. Stations
89 * can be removed by the REMOVE_STA command.
90 *
91 * All the data related to a station is held in the structure %iwl_sta
92 * which is embed in the mac80211's %ieee80211_sta (in the drv_priv) area.
93 * This data includes the index of the station in the fw, per tid information
94 * (sequence numbers, Block-ack state machine, etc...). The stations are
95 * created and deleted by the %sta_state callback from %ieee80211_ops.
96 *
97 * The driver holds a map: %fw_id_to_mac_id that allows to fetch a
98 * %ieee80211_sta (and the %iwl_sta embedded into it) based on a fw
99 * station index. That way, the driver is able to get the tid related data in
100 * O(1) in time sensitive paths (Tx / Tx response / BA notification). These
101 * paths are triggered by the fw, and the driver needs to get a pointer to the
102 * %ieee80211 structure. This map helps to get that pointer quickly.
103 */
104
105 /**
106 * DOC: station table - locking
107 *
108 * As stated before, the station is created / deleted by mac80211's %sta_state
109 * callback from %ieee80211_ops which can sleep. The next paragraph explains
110 * the locking of a single stations, the next ones relates to the station
111 * table.
112 *
113 * The station holds the sequence number per tid. So this data needs to be
114 * accessed in the Tx path (which is softIRQ). It also holds the Block-Ack
115 * information (the state machine / and the logic that checks if the queues
116 * were drained), so it also needs to be accessible from the Tx response flow.
117 * In short, the station needs to be access from sleepable context as well as
118 * from tasklets, so the station itself needs a spinlock.
119 *
120 * The writers of %fw_id_to_mac_id map are serialized by the global mutex of
121 * the mvm op_mode. This is possible since %sta_state can sleep.
122 * The pointers in this map are RCU protected, hence we won't replace the
123 * station while we have Tx / Tx response / BA notification running.
124 *
125 * If a station is deleted while it still has packets in its A-MPDU queues,
126 * then the reclaim flow will notice that there is no station in the map for
127 * sta_id and it will dump the responses.
128 */
129
130 /**
131 * DOC: station table - internal stations
132 *
133 * The FW needs a few internal stations that are not reflected in
134 * mac80211, such as broadcast station in AP / GO mode, or AUX sta for
135 * scanning and P2P device (during the GO negotiation).
136 * For these kind of stations we have %iwl_int_sta struct which holds the
137 * data relevant for them from both %iwl_sta and %ieee80211_sta.
138 * Usually the data for these stations is static, so no locking is required,
139 * and no TID data as this is also not needed.
140 * One thing to note, is that these stations have an ID in the fw, but not
141 * in mac80211. In order to "reserve" them a sta_id in %fw_id_to_mac_id
142 * we fill ERR_PTR(EINVAL) in this mapping and all other dereferencing of
143 * pointers from this mapping need to check that the value is not error
144 * or NULL.
145 *
146 * Currently there is only one auxiliary station for scanning, initialized
147 * on init.
148 */
149
150 /**
151 * DOC: station table - AP Station in STA mode
152 *
153 * %iwl_vif includes the index of the AP station in the fw's STA table:
154 * %ap_sta_id. To get the point to the corresponding %ieee80211_sta,
155 * &fw_id_to_mac_id can be used. Due to the way the fw works, we must not remove
156 * the AP station from the fw before setting the MAC context as unassociated.
157 * Hence, %fw_id_to_mac_id[%ap_sta_id] will be NULLed when the AP station is
158 * removed by mac80211, but the station won't be removed in the fw until the
159 * VIF is set as unassociated. Then, %ap_sta_id will be invalidated.
160 */
161
162 /**
163 * DOC: station table - Drain vs. Flush
164 *
165 * Flush means that all the frames in the SCD queue are dumped regardless the
166 * station to which they were sent. We do that when we disassociate and before
167 * we remove the STA of the AP. The flush can be done synchronously against the
168 * fw.
169 * Drain means that the fw will drop all the frames sent to a specific station.
170 * This is useful when a client (if we are IBSS / GO or AP) disassociates. In
171 * that case, we need to drain all the frames for that client from the AC queues
172 * that are shared with the other clients. Only then, we can remove the STA in
173 * the fw. In order to do so, we track the non-AMPDU packets for each station.
174 * If mac80211 removes a STA and if it still has non-AMPDU packets pending in
175 * the queues, we mark this station as %EBUSY in %fw_id_to_mac_id, and drop all
176 * the frames for this STA (%iwl_rm_sta). When the last frame is dropped
177 * (we know about it with its Tx response), we remove the station in fw and set
178 * it as %NULL in %fw_id_to_mac_id: this is the purpose of
179 * %iwl_sta_drained_wk.
180 */
181
182 /**
183 * DOC: station table - fw restart
184 *
185 * When the fw asserts, or we have any other issue that requires to reset the
186 * driver, we require mac80211 to reconfigure the driver. Since the private
187 * data of the stations is embed in mac80211's %ieee80211_sta, that data will
188 * not be zeroed and needs to be reinitialized manually.
189 * %IWL_STATUS_IN_HW_RESTART is set during restart and that will hint us
190 * that we must not allocate a new sta_id but reuse the previous one. This
191 * means that the stations being re-added after the reset will have the same
192 * place in the fw as before the reset. We do need to zero the %fw_id_to_mac_id
193 * map, since the stations aren't in the fw any more. Internal stations that
194 * are not added by mac80211 will be re-added in the init flow that is called
195 * after the restart: mac80211 call's %iwl_mac_start which calls to
196 * %iwl_up.
197 */
198
199 /**
200 * Send the STA info to the FW.
201 *
202 * @sc: the iwm_softc* to use
203 * @sta: the STA
204 * @update: this is true if the FW is being updated about a STA it already knows
205 * about. Otherwise (if this is a new STA), this should be false.
206 * @flags: if update==true, this marks what is being changed via ORs of values
207 * from enum iwm_sta_modify_flag. Otherwise, this is ignored.
208 */
209 extern int iwm_sta_send_to_fw(struct iwm_softc *sc, struct iwm_node *in,
210 boolean_t update);
211 extern int iwm_add_sta(struct iwm_softc *sc, struct iwm_node *in);
212 extern int iwm_update_sta(struct iwm_softc *sc, struct iwm_node *in);
213 extern int iwm_rm_sta(struct iwm_softc *sc, struct ieee80211vap *vap,
214 boolean_t is_assoc);
215 extern int iwm_rm_sta_id(struct iwm_softc *sc, struct ieee80211vap *vap);
216
217 extern int iwm_add_aux_sta(struct iwm_softc *sc);
218 extern void iwm_del_aux_sta(struct iwm_softc *sc);
219
220 extern int iwm_drain_sta(struct iwm_softc *sc, struct iwm_vap *ivp,
221 boolean_t drain);
222
223 #endif /* __IF_IWM_STA_H__ */
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