drivers/net/wireless/iwlwifi/mvm/scan.c

   1 /******************************************************************************
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  53  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  54  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  62  *****************************************************************************/
  63
  64 #include <linux/etherdevice.h>
  65 #include <net/mac80211.h>
  66
  67 #include "mvm.h"
  68 #include "iwl-eeprom-parse.h"
  69 #include "fw-api-scan.h"
  70
  71 #define IWL_PLCP_QUIET_THRESH 1
  72 #define IWL_ACTIVE_QUIET_TIME 10
  73
  74 static inline __le16 iwl_mvm_scan_rx_chain(struct iwl_mvm *mvm)
  75 {
  76         u16 rx_chain;
  77         u8 rx_ant = iwl_fw_valid_rx_ant(mvm->fw);
  78
  79         rx_chain = rx_ant << PHY_RX_CHAIN_VALID_POS;
  80         rx_chain |= rx_ant << PHY_RX_CHAIN_FORCE_MIMO_SEL_POS;
  81         rx_chain |= rx_ant << PHY_RX_CHAIN_FORCE_SEL_POS;
  82         rx_chain |= 0x1 << PHY_RX_CHAIN_DRIVER_FORCE_POS;
  83         return cpu_to_le16(rx_chain);
  84 }
  85
  86 static inline __le32 iwl_mvm_scan_max_out_time(struct ieee80211_vif *vif)
  87 {
  88         if (vif->bss_conf.assoc)
  89                 return cpu_to_le32(200 * 1024);
  90         else
  91                 return 0;
  92 }
  93
  94 static inline __le32 iwl_mvm_scan_suspend_time(struct ieee80211_vif *vif)
  95 {
  96         if (vif->bss_conf.assoc)
  97                 return cpu_to_le32(vif->bss_conf.beacon_int);
  98         else
  99                 return 0;
 100 }
 101
 102 static inline __le32
 103 iwl_mvm_scan_rxon_flags(struct cfg80211_scan_request *req)
 104 {
 105         if (req->channels[0]->band == IEEE80211_BAND_2GHZ)
 106                 return cpu_to_le32(PHY_BAND_24);
 107         else
 108                 return cpu_to_le32(PHY_BAND_5);
 109 }
 110
 111 static inline __le32
 112 iwl_mvm_scan_rate_n_flags(struct iwl_mvm *mvm, enum ieee80211_band band,
 113                           bool no_cck)
 114 {
 115         u32 tx_ant;
 116
 117         mvm->scan_last_antenna_idx =
 118                 iwl_mvm_next_antenna(mvm, iwl_fw_valid_tx_ant(mvm->fw),
 119                                      mvm->scan_last_antenna_idx);
 120         tx_ant = BIT(mvm->scan_last_antenna_idx) << RATE_MCS_ANT_POS;
 121
 122         if (band == IEEE80211_BAND_2GHZ && !no_cck)
 123                 return cpu_to_le32(IWL_RATE_1M_PLCP | RATE_MCS_CCK_MSK |
 124                                    tx_ant);
 125         else
 126                 return cpu_to_le32(IWL_RATE_6M_PLCP | tx_ant);
 127 }
 128
 129 /*
 130  * We insert the SSIDs in an inverted order, because the FW will
 131  * invert it back. The most prioritized SSID, which is first in the
 132  * request list, is not copied here, but inserted directly to the probe
 133  * request.
 134  */
 135 static void iwl_mvm_scan_fill_ssids(struct iwl_scan_cmd *cmd,
 136                                     struct cfg80211_scan_request *req)
 137 {
 138         int fw_idx, req_idx;
 139
 140         for (req_idx = req->n_ssids - 1, fw_idx = 0; req_idx > 0;
 141              req_idx--, fw_idx++) {
 142                 cmd->direct_scan[fw_idx].id = WLAN_EID_SSID;
 143                 cmd->direct_scan[fw_idx].len = req->ssids[req_idx].ssid_len;
 144                 memcpy(cmd->direct_scan[fw_idx].ssid,
 145                        req->ssids[req_idx].ssid,
 146                        req->ssids[req_idx].ssid_len);
 147         }
 148 }
 149
 150 /*
 151  * If req->n_ssids > 0, it means we should do an active scan.
 152  * In case of active scan w/o directed scan, we receive a zero-length SSID
 153  * just to notify that this scan is active and not passive.
 154  * In order to notify the FW of the number of SSIDs we wish to scan (including
 155  * the zero-length one), we need to set the corresponding bits in chan->type,
 156  * one for each SSID, and set the active bit (first). The first SSID is already
 157  * included in the probe template, so we need to set only req->n_ssids - 1 bits
 158  * in addition to the first bit.
 159  */
 160 static u16 iwl_mvm_get_active_dwell(enum ieee80211_band band, int n_ssids)
 161 {
 162         if (band == IEEE80211_BAND_2GHZ)
 163                 return 30  + 3 * (n_ssids + 1);
 164         return 20  + 2 * (n_ssids + 1);
 165 }
 166
 167 static u16 iwl_mvm_get_passive_dwell(enum ieee80211_band band)
 168 {
 169         return band == IEEE80211_BAND_2GHZ ? 100 + 20 : 100 + 10;
 170 }
 171
 172 static void iwl_mvm_scan_fill_channels(struct iwl_scan_cmd *cmd,
 173                                        struct cfg80211_scan_request *req)
 174 {
 175         u16 passive_dwell = iwl_mvm_get_passive_dwell(req->channels[0]->band);
 176         u16 active_dwell = iwl_mvm_get_active_dwell(req->channels[0]->band,
 177                                                     req->n_ssids);
 178         struct iwl_scan_channel *chan = (struct iwl_scan_channel *)
 179                 (cmd->data + le16_to_cpu(cmd->tx_cmd.len));
 180         int i;
 181
 182         for (i = 0; i < cmd->channel_count; i++) {
 183                 chan->channel = cpu_to_le16(req->channels[i]->hw_value);
 184                 chan->type = cpu_to_le32(BIT(req->n_ssids) - 1);
 185                 if (req->channels[i]->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 186                         chan->type &= cpu_to_le32(~SCAN_CHANNEL_TYPE_ACTIVE);
 187                 chan->active_dwell = cpu_to_le16(active_dwell);
 188                 chan->passive_dwell = cpu_to_le16(passive_dwell);
 189                 chan->iteration_count = cpu_to_le16(1);
 190                 chan++;
 191         }
 192 }
 193
 194 /*
 195  * Fill in probe request with the following parameters:
 196  * TA is our vif HW address, which mac80211 ensures we have.
 197  * Packet is broadcasted, so this is both SA and DA.
 198  * The probe request IE is made out of two: first comes the most prioritized
 199  * SSID if a directed scan is requested. Second comes whatever extra
 200  * information was given to us as the scan request IE.
 201  */
 202 static u16 iwl_mvm_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 203                                   int n_ssids, const u8 *ssid, int ssid_len,
 204                                   const u8 *ie, int ie_len,
 205                                   int left)
 206 {
 207         int len = 0;
 208         u8 *pos = NULL;
 209
 210         /* Make sure there is enough space for the probe request,
 211          * two mandatory IEs and the data */
 212         left -= 24;
 213         if (left < 0)
 214                 return 0;
 215
 216         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 217         eth_broadcast_addr(frame->da);
 218         memcpy(frame->sa, ta, ETH_ALEN);
 219         eth_broadcast_addr(frame->bssid);
 220         frame->seq_ctrl = 0;
 221
 222         len += 24;
 223
 224         /* for passive scans, no need to fill anything */
 225         if (n_ssids == 0)
 226                 return (u16)len;
 227
 228         /* points to the payload of the request */
 229         pos = &frame->u.probe_req.variable[0];
 230
 231         /* fill in our SSID IE */
 232         left -= ssid_len + 2;
 233         if (left < 0)
 234                 return 0;
 235         *pos++ = WLAN_EID_SSID;
 236         *pos++ = ssid_len;
 237         if (ssid && ssid_len) { /* ssid_len may be == 0 even if ssid is valid */
 238                 memcpy(pos, ssid, ssid_len);
 239                 pos += ssid_len;
 240         }
 241
 242         len += ssid_len + 2;
 243
 244         if (WARN_ON(left < ie_len))
 245                 return len;
 246
 247         if (ie && ie_len) {
 248                 memcpy(pos, ie, ie_len);
 249                 len += ie_len;
 250         }
 251
 252         return (u16)len;
 253 }
 254
 255 int iwl_mvm_scan_request(struct iwl_mvm *mvm,
 256                          struct ieee80211_vif *vif,
 257                          struct cfg80211_scan_request *req)
 258 {
 259         struct iwl_host_cmd hcmd = {
 260                 .id = SCAN_REQUEST_CMD,
 261                 .len = { 0, },
 262                 .data = { mvm->scan_cmd, },
 263                 .flags = CMD_SYNC,
 264                 .dataflags = { IWL_HCMD_DFL_NOCOPY, },
 265         };
 266         struct iwl_scan_cmd *cmd = mvm->scan_cmd;
 267         int ret;
 268         u32 status;
 269         int ssid_len = 0;
 270         u8 *ssid = NULL;
 271
 272         lockdep_assert_held(&mvm->mutex);
 273         BUG_ON(mvm->scan_cmd == NULL);
 274
 275         IWL_DEBUG_SCAN(mvm, "Handling mac80211 scan request\n");
 276         mvm->scan_status = IWL_MVM_SCAN_OS;
 277         memset(cmd, 0, sizeof(struct iwl_scan_cmd) +
 278                mvm->fw->ucode_capa.max_probe_length +
 279                (MAX_NUM_SCAN_CHANNELS * sizeof(struct iwl_scan_channel)));
 280
 281         cmd->channel_count = (u8)req->n_channels;
 282         cmd->quiet_time = cpu_to_le16(IWL_ACTIVE_QUIET_TIME);
 283         cmd->quiet_plcp_th = cpu_to_le16(IWL_PLCP_QUIET_THRESH);
 284         cmd->rxchain_sel_flags = iwl_mvm_scan_rx_chain(mvm);
 285         cmd->max_out_time = iwl_mvm_scan_max_out_time(vif);
 286         cmd->suspend_time = iwl_mvm_scan_suspend_time(vif);
 287         cmd->rxon_flags = iwl_mvm_scan_rxon_flags(req);
 288         cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP |
 289                                         MAC_FILTER_IN_BEACON);
 290
 291         if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
 292                 cmd->type = cpu_to_le32(SCAN_TYPE_DISCOVERY_FORCED);
 293         else
 294                 cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);
 295
 296         cmd->repeats = cpu_to_le32(1);
 297
 298         /*
 299          * If the user asked for passive scan, don't change to active scan if
 300          * you see any activity on the channel - remain passive.
 301          */
 302         if (req->n_ssids > 0) {
 303                 cmd->passive2active = cpu_to_le16(1);
 304                 cmd->scan_flags |= SCAN_FLAGS_PASSIVE2ACTIVE;
 305                 ssid = req->ssids[0].ssid;
 306                 ssid_len = req->ssids[0].ssid_len;
 307         } else {
 308                 cmd->passive2active = 0;
 309                 cmd->scan_flags &= ~SCAN_FLAGS_PASSIVE2ACTIVE;
 310         }
 311
 312         iwl_mvm_scan_fill_ssids(cmd, req);
 313
 314         cmd->tx_cmd.tx_flags = cpu_to_le32(TX_CMD_FLG_SEQ_CTL);
 315         cmd->tx_cmd.sta_id = mvm->aux_sta.sta_id;
 316         cmd->tx_cmd.life_time = cpu_to_le32(TX_CMD_LIFE_TIME_INFINITE);
 317         cmd->tx_cmd.rate_n_flags =
 318                         iwl_mvm_scan_rate_n_flags(mvm, req->channels[0]->band,
 319                                                   req->no_cck);
 320
 321         cmd->tx_cmd.len =
 322                 cpu_to_le16(iwl_mvm_fill_probe_req(
 323                             (struct ieee80211_mgmt *)cmd->data,
 324                             vif->addr,
 325                             req->n_ssids, ssid, ssid_len,
 326                             req->ie, req->ie_len,
 327                             mvm->fw->ucode_capa.max_probe_length));
 328
 329         iwl_mvm_scan_fill_channels(cmd, req);
 330
 331         cmd->len = cpu_to_le16(sizeof(struct iwl_scan_cmd) +
 332                 le16_to_cpu(cmd->tx_cmd.len) +
 333                 (cmd->channel_count * sizeof(struct iwl_scan_channel)));
 334         hcmd.len[0] = le16_to_cpu(cmd->len);
 335
 336         status = SCAN_RESPONSE_OK;
 337         ret = iwl_mvm_send_cmd_status(mvm, &hcmd, &status);
 338         if (!ret && status == SCAN_RESPONSE_OK) {
 339                 IWL_DEBUG_SCAN(mvm, "Scan request was sent successfully\n");
 340         } else {
 341                 /*
 342                  * If the scan failed, it usually means that the FW was unable
 343                  * to allocate the time events. Warn on it, but maybe we
 344                  * should try to send the command again with different params.
 345                  */
 346                 IWL_ERR(mvm, "Scan failed! status 0x%x ret %d\n",
 347                         status, ret);
 348                 mvm->scan_status = IWL_MVM_SCAN_NONE;
 349                 ret = -EIO;
 350         }
 351         return ret;
 352 }
 353
 354 int iwl_mvm_rx_scan_response(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 355                           struct iwl_device_cmd *cmd)
 356 {
 357         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 358         struct iwl_cmd_response *resp = (void *)pkt->data;
 359
 360         IWL_DEBUG_SCAN(mvm, "Scan response received. status 0x%x\n",
 361                        le32_to_cpu(resp->status));
 362         return 0;
 363 }
 364
 365 int iwl_mvm_rx_scan_complete(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 366                           struct iwl_device_cmd *cmd)
 367 {
 368         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 369         struct iwl_scan_complete_notif *notif = (void *)pkt->data;
 370
 371         IWL_DEBUG_SCAN(mvm, "Scan complete: status=0x%x scanned channels=%d\n",
 372                        notif->status, notif->scanned_channels);
 373
 374         mvm->scan_status = IWL_MVM_SCAN_NONE;
 375         ieee80211_scan_completed(mvm->hw, notif->status != SCAN_COMP_STATUS_OK);
 376
 377         return 0;
 378 }
 379
 380 static bool iwl_mvm_scan_abort_notif(struct iwl_notif_wait_data *notif_wait,
 381                                      struct iwl_rx_packet *pkt, void *data)
 382 {
 383         struct iwl_mvm *mvm =
 384                 container_of(notif_wait, struct iwl_mvm, notif_wait);
 385         struct iwl_scan_complete_notif *notif;
 386         u32 *resp;
 387
 388         switch (pkt->hdr.cmd) {
 389         case SCAN_ABORT_CMD:
 390                 resp = (void *)pkt->data;
 391                 if (*resp == CAN_ABORT_STATUS) {
 392                         IWL_DEBUG_SCAN(mvm,
 393                                        "Scan can be aborted, wait until completion\n");
 394                         return false;
 395                 }
 396
 397                 /*
 398                  * If scan cannot be aborted, it means that we had a
 399                  * SCAN_COMPLETE_NOTIFICATION in the pipe and it called
 400                  * ieee80211_scan_completed already.
 401                  */
 402                 IWL_DEBUG_SCAN(mvm, "Scan cannot be aborted, exit now: %d\n",
 403                                *resp);
 404                 return true;
 405
 406         case SCAN_COMPLETE_NOTIFICATION:
 407                 notif = (void *)pkt->data;
 408                 IWL_DEBUG_SCAN(mvm, "Scan aborted: status 0x%x\n",
 409                                notif->status);
 410                 return true;
 411
 412         default:
 413                 WARN_ON(1);
 414                 return false;
 415         };
 416 }
 417
 418 void iwl_mvm_cancel_scan(struct iwl_mvm *mvm)
 419 {
 420         struct iwl_notification_wait wait_scan_abort;
 421         static const u8 scan_abort_notif[] = { SCAN_ABORT_CMD,
 422                                                SCAN_COMPLETE_NOTIFICATION };
 423         int ret;
 424
 425         if (mvm->scan_status == IWL_MVM_SCAN_NONE)
 426                 return;
 427
 428         iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_abort,
 429                                    scan_abort_notif,
 430                                    ARRAY_SIZE(scan_abort_notif),
 431                                    iwl_mvm_scan_abort_notif, NULL);
 432
 433         ret = iwl_mvm_send_cmd_pdu(mvm, SCAN_ABORT_CMD,
 434                                    CMD_SYNC | CMD_SEND_IN_RFKILL, 0, NULL);
 435         if (ret) {
 436                 IWL_ERR(mvm, "Couldn't send SCAN_ABORT_CMD: %d\n", ret);
 437                 /* mac80211's state will be cleaned in the fw_restart flow */
 438                 goto out_remove_notif;
 439         }
 440
 441         ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_abort, 1 * HZ);
 442         if (ret)
 443                 IWL_ERR(mvm, "%s - failed on timeout\n", __func__);
 444
 445         return;
 446
 447 out_remove_notif:
 448         iwl_remove_notification(&mvm->notif_wait, &wait_scan_abort);
 449 }