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__ */ 224