drivers/net/wireless/iwlwifi/mvm/sta.h

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  63
  64 #ifndef __sta_h__
  65 #define __sta_h__
  66
  67 #include <linux/spinlock.h>
  68 #include <net/mac80211.h>
  69 #include <linux/wait.h>
  70
  71 #include "iwl-trans.h" /* for IWL_MAX_TID_COUNT */
  72 #include "fw-api.h" /* IWL_MVM_STATION_COUNT */
  73 #include "rs.h"
  74
  75 struct iwl_mvm;
  76
  77 /**
  78  * DOC: station table - introduction
  79  *
  80  * The station table is a list of data structure that reprensent the stations.
  81  * In STA/P2P client mode, the driver will hold one station for the AP/ GO.
  82  * In GO/AP mode, the driver will have as many stations as associated clients.
  83  * All these stations are reflected in the fw's station table. The driver
  84  * keeps the fw's station table up to date with the ADD_STA command. Stations
  85  * can be removed by the REMOVE_STA command.
  86  *
  87  * All the data related to a station is held in the structure %iwl_mvm_sta
  88  * which is embed in the mac80211's %ieee80211_sta (in the drv_priv) area.
  89  * This data includes the index of the station in the fw, per tid information
  90  * (sequence numbers, Block-ack state machine, etc...). The stations are
  91  * created and deleted by the %sta_state callback from %ieee80211_ops.
  92  *
  93  * The driver holds a map: %fw_id_to_mac_id that allows to fetch a
  94  * %ieee80211_sta (and the %iwl_mvm_sta embedded into it) based on a fw
  95  * station index. That way, the driver is able to get the tid related data in
  96  * O(1) in time sensitive paths (Tx / Tx response / BA notification). These
  97  * paths are triggered by the fw, and the driver needs to get a pointer to the
  98  * %ieee80211 structure. This map helps to get that pointer quickly.
  99  */
 100
 101 /**
 102  * DOC: station table - locking
 103  *
 104  * As stated before, the station is created / deleted by mac80211's %sta_state
 105  * callback from %ieee80211_ops which can sleep. The next paragraph explains
 106  * the locking of a single stations, the next ones relates to the station
 107  * table.
 108  *
 109  * The station holds the sequence number per tid. So this data needs to be
 110  * accessed in the Tx path (which is softIRQ). It also holds the Block-Ack
 111  * information (the state machine / and the logic that checks if the queues
 112  * were drained), so it also needs to be accessible from the Tx response flow.
 113  * In short, the station needs to be access from sleepable context as well as
 114  * from tasklets, so the station itself needs a spinlock.
 115  *
 116  * The writers of %fw_id_to_mac_id map are serialized by the global mutex of
 117  * the mvm op_mode. This is possible since %sta_state can sleep.
 118  * The pointers in this map are RCU protected, hence we won't replace the
 119  * station while we have Tx / Tx response / BA notification running.
 120  *
 121  * If a station is deleted while it still has packets in its A-MPDU queues,
 122  * then the reclaim flow will notice that there is no station in the map for
 123  * sta_id and it will dump the responses.
 124  */
 125
 126 /**
 127  * DOC: station table - internal stations
 128  *
 129  * The FW needs a few internal stations that are not reflected in
 130  * mac80211, such as broadcast station in AP / GO mode, or AUX sta for
 131  * scanning and P2P device (during the GO negotiation).
 132  * For these kind of stations we have %iwl_mvm_int_sta struct which holds the
 133  * data relevant for them from both %iwl_mvm_sta and %ieee80211_sta.
 134  * Usually the data for these stations is static, so no locking is required,
 135  * and no TID data as this is also not needed.
 136  * One thing to note, is that these stations have an ID in the fw, but not
 137  * in mac80211. In order to "reserve" them a sta_id in %fw_id_to_mac_id
 138  * we fill ERR_PTR(EINVAL) in this mapping and all other dereferencing of
 139  * pointers from this mapping need to check that the value is not error
 140  * or NULL.
 141  *
 142  * Currently there is only one auxiliary station for scanning, initialized
 143  * on init.
 144  */
 145
 146 /**
 147  * DOC: station table - AP Station in STA mode
 148  *
 149  * %iwl_mvm_vif includes the index of the AP station in the fw's STA table:
 150  * %ap_sta_id. To get the point to the coresponsding %ieee80211_sta,
 151  * &fw_id_to_mac_id can be used. Due to the way the fw works, we must not remove
 152  * the AP station from the fw before setting the MAC context as unassociated.
 153  * Hence, %fw_id_to_mac_id[%ap_sta_id] will be NULLed when the AP station is
 154  * removed by mac80211, but the station won't be removed in the fw until the
 155  * VIF is set as unassociated. Then, %ap_sta_id will be invalidated.
 156  */
 157
 158 /**
 159  * DOC: station table - Drain vs. Flush
 160  *
 161  * Flush means that all the frames in the SCD queue are dumped regardless the
 162  * station to which they were sent. We do that when we disassociate and before
 163  * we remove the STA of the AP. The flush can be done synchronously against the
 164  * fw.
 165  * Drain means that the fw will drop all the frames sent to a specific station.
 166  * This is useful when a client (if we are IBSS / GO or AP) disassociates. In
 167  * that case, we need to drain all the frames for that client from the AC queues
 168  * that are shared with the other clients. Only then, we can remove the STA in
 169  * the fw. In order to do so, we track the non-AMPDU packets for each station.
 170  * If mac80211 removes a STA and if it still has non-AMPDU packets pending in
 171  * the queues, we mark this station as %EBUSY in %fw_id_to_mac_id, and drop all
 172  * the frames for this STA (%iwl_mvm_rm_sta). When the last frame is dropped
 173  * (we know about it with its Tx response), we remove the station in fw and set
 174  * it as %NULL in %fw_id_to_mac_id: this is the purpose of
 175  * %iwl_mvm_sta_drained_wk.
 176  */
 177
 178 /**
 179  * DOC: station table - fw restart
 180  *
 181  * When the fw asserts, or we have any other issue that requires to reset the
 182  * driver, we require mac80211 to reconfigure the driver. Since the private
 183  * data of the stations is embed in mac80211's %ieee80211_sta, that data will
 184  * not be zeroed and needs to be reinitialized manually.
 185  * %IWL_MVM_STATUS_IN_HW_RESTART is set during restart and that will hint us
 186  * that we must not allocate a new sta_id but reuse the previous one. This
 187  * means that the stations being re-added after the reset will have the same
 188  * place in the fw as before the reset. We do need to zero the %fw_id_to_mac_id
 189  * map, since the stations aren't in the fw any more. Internal stations that
 190  * are not added by mac80211 will be re-added in the init flow that is called
 191  * after the restart: mac80211 call's %iwl_mvm_mac_start which calls to
 192  * %iwl_mvm_up.
 193  */
 194
 195 /**
 196  * DOC: AP mode - PS
 197  *
 198  * When a station is asleep, the fw will set it as "asleep". All the
 199  * non-aggregation frames to that station will be dropped by the fw
 200  * (%TX_STATUS_FAIL_DEST_PS failure code).
 201  * AMPDUs are in a separate queue that is stopped by the fw. We just need to
 202  * let mac80211 know how many frames we have in these queues so that it can
 203  * properly handle trigger frames.
 204  * When the a trigger frame is received, mac80211 tells the driver to send
 205  * frames from the AMPDU queues or AC queue depending on which queue are
 206  * delivery-enabled and what TID has frames to transmit (Note that mac80211 has
 207  * all the knowledege since all the non-agg frames are buffered / filtered, and
 208  * the driver tells mac80211 about agg frames). The driver needs to tell the fw
 209  * to let frames out even if the station is asleep. This is done by
 210  * %iwl_mvm_sta_modify_sleep_tx_count.
 211  * When we receive a frame from that station with PM bit unset, the
 212  * driver needs to let the fw know that this station isn't alseep any more.
 213  * This is done by %iwl_mvm_sta_modify_ps_wake.
 214  *
 215  * TODO - EOSP handling
 216  */
 217
 218 /**
 219  * enum iwl_mvm_agg_state
 220  *
 221  * The state machine of the BA agreement establishment / tear down.
 222  * These states relate to a specific RA / TID.
 223  *
 224  * @IWL_AGG_OFF: aggregation is not used
 225  * @IWL_AGG_STARTING: aggregation are starting (between start and oper)
 226  * @IWL_AGG_ON: aggregation session is up
 227  * @IWL_EMPTYING_HW_QUEUE_ADDBA: establishing a BA session - waiting for the
 228  *      HW queue to be empty from packets for this RA /TID.
 229  * @IWL_EMPTYING_HW_QUEUE_DELBA: tearing down a BA session - waiting for the
 230  *      HW queue to be empty from packets for this RA /TID.
 231  */
 232 enum iwl_mvm_agg_state {
 233         IWL_AGG_OFF = 0,
 234         IWL_AGG_STARTING,
 235         IWL_AGG_ON,
 236         IWL_EMPTYING_HW_QUEUE_ADDBA,
 237         IWL_EMPTYING_HW_QUEUE_DELBA,
 238 };
 239
 240 /**
 241  * struct iwl_mvm_tid_data - holds the states for each RA / TID
 242  * @seq_number: the next WiFi sequence number to use
 243  * @next_reclaimed: the WiFi sequence number of the next packet to be acked.
 244  *      This is basically (last acked packet++).
 245  * @rate_n_flags: Rate at which Tx was attempted. Holds the data between the
 246  *      Tx response (TX_CMD), and the block ack notification (COMPRESSED_BA).
 247  * @state: state of the BA agreement establishment / tear down.
 248  * @txq_id: Tx queue used by the BA session
 249  * @ssn: the first packet to be sent in AGG HW queue in Tx AGG start flow, or
 250  *      the first packet to be sent in legacy HW queue in Tx AGG stop flow.
 251  *      Basically when next_reclaimed reaches ssn, we can tell mac80211 that
 252  *      we are ready to finish the Tx AGG stop / start flow.
 253  * @wait_for_ba: Expect block-ack before next Tx reply
 254  */
 255 struct iwl_mvm_tid_data {
 256         u16 seq_number;
 257         u16 next_reclaimed;
 258         /* The rest is Tx AGG related */
 259         u32 rate_n_flags;
 260         enum iwl_mvm_agg_state state;
 261         u16 txq_id;
 262         u16 ssn;
 263         bool wait_for_ba;
 264 };
 265
 266 /**
 267  * struct iwl_mvm_sta - representation of a station in the driver
 268  * @sta_id: the index of the station in the fw (will be replaced by id_n_color)
 269  * @tfd_queue_msk: the tfd queues used by the station
 270  * @mac_id_n_color: the MAC context this station is linked to
 271  * @tid_disable_agg: bitmap: if bit(tid) is set, the fw won't send ampdus for
 272  *      tid.
 273  * @max_agg_bufsize: the maximal size of the AGG buffer for this station
 274  * @bt_reduced_txpower: is reduced tx power enabled for this station
 275  * @lock: lock to protect the whole struct. Since %tid_data is access from Tx
 276  * and from Tx response flow, it needs a spinlock.
 277  * @tid_data: per tid data. Look at %iwl_mvm_tid_data.
 278  *
 279  * When mac80211 creates a station it reserves some space (hw->sta_data_size)
 280  * in the structure for use by driver. This structure is placed in that
 281  * space.
 282  *
 283  */
 284 struct iwl_mvm_sta {
 285         u32 sta_id;
 286         u32 tfd_queue_msk;
 287         u32 mac_id_n_color;
 288         u16 tid_disable_agg;
 289         u8 max_agg_bufsize;
 290         bool bt_reduced_txpower;
 291         spinlock_t lock;
 292         struct iwl_mvm_tid_data tid_data[IWL_MAX_TID_COUNT];
 293         struct iwl_lq_sta lq_sta;
 294         struct ieee80211_vif *vif;
 295
 296 #ifdef CONFIG_PM_SLEEP
 297         u16 last_seq_ctl;
 298 #endif
 299 };
 300
 301 /**
 302  * struct iwl_mvm_int_sta - representation of an internal station (auxiliary or
 303  * broadcast)
 304  * @sta_id: the index of the station in the fw (will be replaced by id_n_color)
 305  * @tfd_queue_msk: the tfd queues used by the station
 306  */
 307 struct iwl_mvm_int_sta {
 308         u32 sta_id;
 309         u32 tfd_queue_msk;
 310 };
 311
 312 int iwl_mvm_sta_send_to_fw(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 313                            bool update);
 314 int iwl_mvm_add_sta(struct iwl_mvm *mvm,
 315                     struct ieee80211_vif *vif,
 316                     struct ieee80211_sta *sta);
 317 int iwl_mvm_update_sta(struct iwl_mvm *mvm,
 318                        struct ieee80211_vif *vif,
 319                        struct ieee80211_sta *sta);
 320 int iwl_mvm_rm_sta(struct iwl_mvm *mvm,
 321                    struct ieee80211_vif *vif,
 322                    struct ieee80211_sta *sta);
 323 int iwl_mvm_rm_sta_id(struct iwl_mvm *mvm,
 324                       struct ieee80211_vif *vif,
 325                       u8 sta_id);
 326 int iwl_mvm_set_sta_key(struct iwl_mvm *mvm,
 327                         struct ieee80211_vif *vif,
 328                         struct ieee80211_sta *sta,
 329                         struct ieee80211_key_conf *key,
 330                         bool have_key_offset);
 331 int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm,
 332                            struct ieee80211_vif *vif,
 333                            struct ieee80211_sta *sta,
 334                            struct ieee80211_key_conf *keyconf);
 335
 336 void iwl_mvm_update_tkip_key(struct iwl_mvm *mvm,
 337                              struct ieee80211_vif *vif,
 338                              struct ieee80211_key_conf *keyconf,
 339                              struct ieee80211_sta *sta, u32 iv32,
 340                              u16 *phase1key);
 341
 342 /* AMPDU */
 343 int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 344                        int tid, u16 ssn, bool start);
 345 int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 346                         struct ieee80211_sta *sta, u16 tid, u16 *ssn);
 347 int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 348                         struct ieee80211_sta *sta, u16 tid, u8 buf_size);
 349 int iwl_mvm_sta_tx_agg_stop(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 350                             struct ieee80211_sta *sta, u16 tid);
 351 int iwl_mvm_sta_tx_agg_flush(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 352                             struct ieee80211_sta *sta, u16 tid);
 353
 354 int iwl_mvm_add_aux_sta(struct iwl_mvm *mvm);
 355 int iwl_mvm_allocate_int_sta(struct iwl_mvm *mvm, struct iwl_mvm_int_sta *sta,
 356                              u32 qmask);
 357 void iwl_mvm_dealloc_int_sta(struct iwl_mvm *mvm,
 358                              struct iwl_mvm_int_sta *sta);
 359 int iwl_mvm_send_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 360                            struct iwl_mvm_int_sta *bsta);
 361 int iwl_mvm_send_rm_bcast_sta(struct iwl_mvm *mvm,
 362                               struct iwl_mvm_int_sta *bsta);
 363 int iwl_mvm_add_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 364                           struct iwl_mvm_int_sta *bsta);
 365 int iwl_mvm_rm_bcast_sta(struct iwl_mvm *mvm, struct iwl_mvm_int_sta *bsta);
 366 void iwl_mvm_sta_drained_wk(struct work_struct *wk);
 367 void iwl_mvm_sta_modify_ps_wake(struct iwl_mvm *mvm,
 368                                 struct ieee80211_sta *sta);
 369 void iwl_mvm_sta_modify_sleep_tx_count(struct iwl_mvm *mvm,
 370                                        struct ieee80211_sta *sta,
 371                                        enum ieee80211_frame_release_type reason,
 372                                        u16 cnt);
 373 int iwl_mvm_drain_sta(struct iwl_mvm *mvm, struct iwl_mvm_sta *mvmsta,
 374                       bool drain);
 375
 376 #endif /* __sta_h__ */