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

   1 /******************************************************************************
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  51  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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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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  60  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  61  *
  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).
 157  */
 158 static u16 iwl_mvm_get_active_dwell(enum ieee80211_band band, int n_ssids)
 159 {
 160         if (band == IEEE80211_BAND_2GHZ)
 161                 return 30  + 3 * (n_ssids + 1);
 162         return 20  + 2 * (n_ssids + 1);
 163 }
 164
 165 static u16 iwl_mvm_get_passive_dwell(enum ieee80211_band band)
 166 {
 167         return band == IEEE80211_BAND_2GHZ ? 100 + 20 : 100 + 10;
 168 }
 169
 170 static void iwl_mvm_scan_fill_channels(struct iwl_scan_cmd *cmd,
 171                                        struct cfg80211_scan_request *req)
 172 {
 173         u16 passive_dwell = iwl_mvm_get_passive_dwell(req->channels[0]->band);
 174         u16 active_dwell = iwl_mvm_get_active_dwell(req->channels[0]->band,
 175                                                     req->n_ssids);
 176         struct iwl_scan_channel *chan = (struct iwl_scan_channel *)
 177                 (cmd->data + le16_to_cpu(cmd->tx_cmd.len));
 178         int i;
 179
 180         for (i = 0; i < cmd->channel_count; i++) {
 181                 chan->channel = cpu_to_le16(req->channels[i]->hw_value);
 182                 chan->type = cpu_to_le32(BIT(req->n_ssids) - 1);
 183                 if (req->channels[i]->flags & IEEE80211_CHAN_PASSIVE_SCAN)
 184                         chan->type &= cpu_to_le32(~SCAN_CHANNEL_TYPE_ACTIVE);
 185                 chan->active_dwell = cpu_to_le16(active_dwell);
 186                 chan->passive_dwell = cpu_to_le16(passive_dwell);
 187                 chan->iteration_count = cpu_to_le16(1);
 188                 chan++;
 189         }
 190 }
 191
 192 /*
 193  * Fill in probe request with the following parameters:
 194  * TA is our vif HW address, which mac80211 ensures we have.
 195  * Packet is broadcasted, so this is both SA and DA.
 196  * The probe request IE is made out of two: first comes the most prioritized
 197  * SSID if a directed scan is requested. Second comes whatever extra
 198  * information was given to us as the scan request IE.
 199  */
 200 static u16 iwl_mvm_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 201                                   int n_ssids, const u8 *ssid, int ssid_len,
 202                                   const u8 *ie, int ie_len,
 203                                   int left)
 204 {
 205         int len = 0;
 206         u8 *pos = NULL;
 207
 208         /* Make sure there is enough space for the probe request,
 209          * two mandatory IEs and the data */
 210         left -= 24;
 211         if (left < 0)
 212                 return 0;
 213
 214         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 215         eth_broadcast_addr(frame->da);
 216         memcpy(frame->sa, ta, ETH_ALEN);
 217         eth_broadcast_addr(frame->bssid);
 218         frame->seq_ctrl = 0;
 219
 220         len += 24;
 221
 222         /* for passive scans, no need to fill anything */
 223         if (n_ssids == 0)
 224                 return (u16)len;
 225
 226         /* points to the payload of the request */
 227         pos = &frame->u.probe_req.variable[0];
 228
 229         /* fill in our SSID IE */
 230         left -= ssid_len + 2;
 231         if (left < 0)
 232                 return 0;
 233         *pos++ = WLAN_EID_SSID;
 234         *pos++ = ssid_len;
 235         if (ssid && ssid_len) { /* ssid_len may be == 0 even if ssid is valid */
 236                 memcpy(pos, ssid, ssid_len);
 237                 pos += ssid_len;
 238         }
 239
 240         len += ssid_len + 2;
 241
 242         if (WARN_ON(left < ie_len))
 243                 return len;
 244
 245         if (ie && ie_len) {
 246                 memcpy(pos, ie, ie_len);
 247                 len += ie_len;
 248         }
 249
 250         return (u16)len;
 251 }
 252
 253 int iwl_mvm_scan_request(struct iwl_mvm *mvm,
 254                          struct ieee80211_vif *vif,
 255                          struct cfg80211_scan_request *req)
 256 {
 257         struct iwl_host_cmd hcmd = {
 258                 .id = SCAN_REQUEST_CMD,
 259                 .len = { 0, },
 260                 .data = { mvm->scan_cmd, },
 261                 .flags = CMD_SYNC,
 262                 .dataflags = { IWL_HCMD_DFL_NOCOPY, },
 263         };
 264         struct iwl_scan_cmd *cmd = mvm->scan_cmd;
 265         int ret;
 266         u32 status;
 267         int ssid_len = 0;
 268         u8 *ssid = NULL;
 269
 270         lockdep_assert_held(&mvm->mutex);
 271         BUG_ON(mvm->scan_cmd == NULL);
 272
 273         IWL_DEBUG_SCAN(mvm, "Handling mac80211 scan request\n");
 274         mvm->scan_status = IWL_MVM_SCAN_OS;
 275         memset(cmd, 0, sizeof(struct iwl_scan_cmd) +
 276                mvm->fw->ucode_capa.max_probe_length +
 277                (MAX_NUM_SCAN_CHANNELS * sizeof(struct iwl_scan_channel)));
 278
 279         cmd->channel_count = (u8)req->n_channels;
 280         cmd->quiet_time = cpu_to_le16(IWL_ACTIVE_QUIET_TIME);
 281         cmd->quiet_plcp_th = cpu_to_le16(IWL_PLCP_QUIET_THRESH);
 282         cmd->rxchain_sel_flags = iwl_mvm_scan_rx_chain(mvm);
 283         cmd->max_out_time = iwl_mvm_scan_max_out_time(vif);
 284         cmd->suspend_time = iwl_mvm_scan_suspend_time(vif);
 285         cmd->rxon_flags = iwl_mvm_scan_rxon_flags(req);
 286         cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP |
 287                                         MAC_FILTER_IN_BEACON);
 288
 289         if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
 290                 cmd->type = cpu_to_le32(SCAN_TYPE_DISCOVERY_FORCED);
 291         else
 292                 cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);
 293
 294         /*
 295          * TODO: This is a WA due to a bug in the FW AUX framework that does not
 296          * properly handle time events that fail to be scheduled
 297          */
 298         cmd->type = cpu_to_le32(SCAN_TYPE_FORCED);
 299
 300         cmd->repeats = cpu_to_le32(1);
 301
 302         /*
 303          * If the user asked for passive scan, don't change to active scan if
 304          * you see any activity on the channel - remain passive.
 305          */
 306         if (req->n_ssids > 0) {
 307                 cmd->passive2active = cpu_to_le16(1);
 308                 ssid = req->ssids[0].ssid;
 309                 ssid_len = req->ssids[0].ssid_len;
 310         } else {
 311                 cmd->passive2active = 0;
 312         }
 313
 314         iwl_mvm_scan_fill_ssids(cmd, req);
 315
 316         cmd->tx_cmd.tx_flags = cpu_to_le32(TX_CMD_FLG_SEQ_CTL |
 317                                            TX_CMD_FLG_BT_DIS);
 318         cmd->tx_cmd.sta_id = mvm->aux_sta.sta_id;
 319         cmd->tx_cmd.life_time = cpu_to_le32(TX_CMD_LIFE_TIME_INFINITE);
 320         cmd->tx_cmd.rate_n_flags =
 321                         iwl_mvm_scan_rate_n_flags(mvm, req->channels[0]->band,
 322                                                   req->no_cck);
 323
 324         cmd->tx_cmd.len =
 325                 cpu_to_le16(iwl_mvm_fill_probe_req(
 326                             (struct ieee80211_mgmt *)cmd->data,
 327                             vif->addr,
 328                             req->n_ssids, ssid, ssid_len,
 329                             req->ie, req->ie_len,
 330                             mvm->fw->ucode_capa.max_probe_length));
 331
 332         iwl_mvm_scan_fill_channels(cmd, req);
 333
 334         cmd->len = cpu_to_le16(sizeof(struct iwl_scan_cmd) +
 335                 le16_to_cpu(cmd->tx_cmd.len) +
 336                 (cmd->channel_count * sizeof(struct iwl_scan_channel)));
 337         hcmd.len[0] = le16_to_cpu(cmd->len);
 338
 339         status = SCAN_RESPONSE_OK;
 340         ret = iwl_mvm_send_cmd_status(mvm, &hcmd, &status);
 341         if (!ret && status == SCAN_RESPONSE_OK) {
 342                 IWL_DEBUG_SCAN(mvm, "Scan request was sent successfully\n");
 343         } else {
 344                 /*
 345                  * If the scan failed, it usually means that the FW was unable
 346                  * to allocate the time events. Warn on it, but maybe we
 347                  * should try to send the command again with different params.
 348                  */
 349                 IWL_ERR(mvm, "Scan failed! status 0x%x ret %d\n",
 350                         status, ret);
 351                 mvm->scan_status = IWL_MVM_SCAN_NONE;
 352                 ret = -EIO;
 353         }
 354         return ret;
 355 }
 356
 357 int iwl_mvm_rx_scan_response(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 358                           struct iwl_device_cmd *cmd)
 359 {
 360         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 361         struct iwl_cmd_response *resp = (void *)pkt->data;
 362
 363         IWL_DEBUG_SCAN(mvm, "Scan response received. status 0x%x\n",
 364                        le32_to_cpu(resp->status));
 365         return 0;
 366 }
 367
 368 int iwl_mvm_rx_scan_complete(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 369                           struct iwl_device_cmd *cmd)
 370 {
 371         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 372         struct iwl_scan_complete_notif *notif = (void *)pkt->data;
 373
 374         IWL_DEBUG_SCAN(mvm, "Scan complete: status=0x%x scanned channels=%d\n",
 375                        notif->status, notif->scanned_channels);
 376
 377         mvm->scan_status = IWL_MVM_SCAN_NONE;
 378         ieee80211_scan_completed(mvm->hw, notif->status != SCAN_COMP_STATUS_OK);
 379
 380         return 0;
 381 }
 382
 383 static bool iwl_mvm_scan_abort_notif(struct iwl_notif_wait_data *notif_wait,
 384                                      struct iwl_rx_packet *pkt, void *data)
 385 {
 386         struct iwl_mvm *mvm =
 387                 container_of(notif_wait, struct iwl_mvm, notif_wait);
 388         struct iwl_scan_complete_notif *notif;
 389         u32 *resp;
 390
 391         switch (pkt->hdr.cmd) {
 392         case SCAN_ABORT_CMD:
 393                 resp = (void *)pkt->data;
 394                 if (*resp == CAN_ABORT_STATUS) {
 395                         IWL_DEBUG_SCAN(mvm,
 396                                        "Scan can be aborted, wait until completion\n");
 397                         return false;
 398                 }
 399
 400                 IWL_DEBUG_SCAN(mvm, "Scan cannot be aborted, exit now: %d\n",
 401                                *resp);
 402                 return true;
 403
 404         case SCAN_COMPLETE_NOTIFICATION:
 405                 notif = (void *)pkt->data;
 406                 IWL_DEBUG_SCAN(mvm, "Scan aborted: status 0x%x\n",
 407                                notif->status);
 408                 return true;
 409
 410         default:
 411                 WARN_ON(1);
 412                 return false;
 413         };
 414 }
 415
 416 void iwl_mvm_cancel_scan(struct iwl_mvm *mvm)
 417 {
 418         struct iwl_notification_wait wait_scan_abort;
 419         static const u8 scan_abort_notif[] = { SCAN_ABORT_CMD,
 420                                                SCAN_COMPLETE_NOTIFICATION };
 421         int ret;
 422
 423         iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_abort,
 424                                    scan_abort_notif,
 425                                    ARRAY_SIZE(scan_abort_notif),
 426                                    iwl_mvm_scan_abort_notif, NULL);
 427
 428         ret = iwl_mvm_send_cmd_pdu(mvm, SCAN_ABORT_CMD, CMD_SYNC, 0, NULL);
 429         if (ret) {
 430                 IWL_ERR(mvm, "Couldn't send SCAN_ABORT_CMD: %d\n", ret);
 431                 goto out_remove_notif;
 432         }
 433
 434         ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_abort, 1 * HZ);
 435         if (ret)
 436                 IWL_ERR(mvm, "%s - failed on timeout\n", __func__);
 437
 438         return;
 439
 440 out_remove_notif:
 441         iwl_remove_notification(&mvm->notif_wait, &wait_scan_abort);
 442 }