Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / wireless / iwlwifi / dvm / scan.c
diff --git a/kernel/drivers/net/wireless/iwlwifi/dvm/scan.c b/kernel/drivers/net/wireless/iwlwifi/dvm/scan.c
new file mode 100644 (file)
index 0000000..43bef90
--- /dev/null
@@ -0,0 +1,1084 @@
+/******************************************************************************
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
+ * USA
+ *
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *****************************************************************************/
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/etherdevice.h>
+#include <net/mac80211.h>
+
+#include "dev.h"
+#include "agn.h"
+
+/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
+ * sending probe req.  This should be set long enough to hear probe responses
+ * from more than one AP.  */
+#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
+#define IWL_ACTIVE_DWELL_TIME_52    (20)
+
+#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
+#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
+
+/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
+ * Must be set longer than active dwell time.
+ * For the most reliable scan, set > AP beacon interval (typically 100msec). */
+#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
+#define IWL_PASSIVE_DWELL_TIME_52   (10)
+#define IWL_PASSIVE_DWELL_BASE      (100)
+#define IWL_CHANNEL_TUNE_TIME       5
+#define MAX_SCAN_CHANNEL           50
+
+/* For reset radio, need minimal dwell time only */
+#define IWL_RADIO_RESET_DWELL_TIME     5
+
+static int iwl_send_scan_abort(struct iwl_priv *priv)
+{
+       int ret;
+       struct iwl_host_cmd cmd = {
+               .id = REPLY_SCAN_ABORT_CMD,
+               .flags = CMD_WANT_SKB,
+       };
+       __le32 *status;
+
+       /* Exit instantly with error when device is not ready
+        * to receive scan abort command or it does not perform
+        * hardware scan currently */
+       if (!test_bit(STATUS_READY, &priv->status) ||
+           !test_bit(STATUS_SCAN_HW, &priv->status) ||
+           test_bit(STATUS_FW_ERROR, &priv->status))
+               return -EIO;
+
+       ret = iwl_dvm_send_cmd(priv, &cmd);
+       if (ret)
+               return ret;
+
+       status = (void *)cmd.resp_pkt->data;
+       if (*status != CAN_ABORT_STATUS) {
+               /* The scan abort will return 1 for success or
+                * 2 for "failure".  A failure condition can be
+                * due to simply not being in an active scan which
+                * can occur if we send the scan abort before we
+                * the microcode has notified us that a scan is
+                * completed. */
+               IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
+                              le32_to_cpu(*status));
+               ret = -EIO;
+       }
+
+       iwl_free_resp(&cmd);
+       return ret;
+}
+
+static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
+{
+       /* check if scan was requested from mac80211 */
+       if (priv->scan_request) {
+               IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
+               ieee80211_scan_completed(priv->hw, aborted);
+       }
+
+       priv->scan_type = IWL_SCAN_NORMAL;
+       priv->scan_vif = NULL;
+       priv->scan_request = NULL;
+}
+
+static void iwl_process_scan_complete(struct iwl_priv *priv)
+{
+       bool aborted;
+
+       lockdep_assert_held(&priv->mutex);
+
+       if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
+               return;
+
+       IWL_DEBUG_SCAN(priv, "Completed scan.\n");
+
+       cancel_delayed_work(&priv->scan_check);
+
+       aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+       if (aborted)
+               IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
+
+       if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
+               goto out_settings;
+       }
+
+       if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
+               int err;
+
+               /* Check if mac80211 requested scan during our internal scan */
+               if (priv->scan_request == NULL)
+                       goto out_complete;
+
+               /* If so request a new scan */
+               err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
+                                       priv->scan_request->channels[0]->band);
+               if (err) {
+                       IWL_DEBUG_SCAN(priv,
+                               "failed to initiate pending scan: %d\n", err);
+                       aborted = true;
+                       goto out_complete;
+               }
+
+               return;
+       }
+
+out_complete:
+       iwl_complete_scan(priv, aborted);
+
+out_settings:
+       /* Can we still talk to firmware ? */
+       if (!iwl_is_ready_rf(priv))
+               return;
+
+       iwlagn_post_scan(priv);
+}
+
+void iwl_force_scan_end(struct iwl_priv *priv)
+{
+       lockdep_assert_held(&priv->mutex);
+
+       if (!test_bit(STATUS_SCANNING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
+               return;
+       }
+
+       IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
+       clear_bit(STATUS_SCANNING, &priv->status);
+       clear_bit(STATUS_SCAN_HW, &priv->status);
+       clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+       clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
+       iwl_complete_scan(priv, true);
+}
+
+static void iwl_do_scan_abort(struct iwl_priv *priv)
+{
+       int ret;
+
+       lockdep_assert_held(&priv->mutex);
+
+       if (!test_bit(STATUS_SCANNING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
+               return;
+       }
+
+       if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
+               return;
+       }
+
+       ret = iwl_send_scan_abort(priv);
+       if (ret) {
+               IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
+               iwl_force_scan_end(priv);
+       } else
+               IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
+}
+
+/**
+ * iwl_scan_cancel - Cancel any currently executing HW scan
+ */
+int iwl_scan_cancel(struct iwl_priv *priv)
+{
+       IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
+       queue_work(priv->workqueue, &priv->abort_scan);
+       return 0;
+}
+
+/**
+ * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
+ * @ms: amount of time to wait (in milliseconds) for scan to abort
+ *
+ */
+void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies(ms);
+
+       lockdep_assert_held(&priv->mutex);
+
+       IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
+
+       iwl_do_scan_abort(priv);
+
+       while (time_before_eq(jiffies, timeout)) {
+               if (!test_bit(STATUS_SCAN_HW, &priv->status))
+                       goto finished;
+               msleep(20);
+       }
+
+       return;
+
+ finished:
+       /*
+        * Now STATUS_SCAN_HW is clear. This means that the
+        * device finished, but the background work is going
+        * to execute at best as soon as we release the mutex.
+        * Since we need to be able to issue a new scan right
+        * after this function returns, run the complete here.
+        * The STATUS_SCAN_COMPLETE bit will then be cleared
+        * and prevent the background work from "completing"
+        * a possible new scan.
+        */
+       iwl_process_scan_complete(priv);
+}
+
+/* Service response to REPLY_SCAN_CMD (0x80) */
+static int iwl_rx_reply_scan(struct iwl_priv *priv,
+                             struct iwl_rx_cmd_buffer *rxb,
+                             struct iwl_device_cmd *cmd)
+{
+#ifdef CONFIG_IWLWIFI_DEBUG
+       struct iwl_rx_packet *pkt = rxb_addr(rxb);
+       struct iwl_scanreq_notification *notif = (void *)pkt->data;
+
+       IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
+#endif
+       return 0;
+}
+
+/* Service SCAN_START_NOTIFICATION (0x82) */
+static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
+                                   struct iwl_rx_cmd_buffer *rxb,
+                                   struct iwl_device_cmd *cmd)
+{
+       struct iwl_rx_packet *pkt = rxb_addr(rxb);
+       struct iwl_scanstart_notification *notif = (void *)pkt->data;
+
+       priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
+       IWL_DEBUG_SCAN(priv, "Scan start: "
+                      "%d [802.11%s] "
+                      "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
+                      notif->channel,
+                      notif->band ? "bg" : "a",
+                      le32_to_cpu(notif->tsf_high),
+                      le32_to_cpu(notif->tsf_low),
+                      notif->status, notif->beacon_timer);
+
+       return 0;
+}
+
+/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
+static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
+                                     struct iwl_rx_cmd_buffer *rxb,
+                                     struct iwl_device_cmd *cmd)
+{
+#ifdef CONFIG_IWLWIFI_DEBUG
+       struct iwl_rx_packet *pkt = rxb_addr(rxb);
+       struct iwl_scanresults_notification *notif = (void *)pkt->data;
+
+       IWL_DEBUG_SCAN(priv, "Scan ch.res: "
+                      "%d [802.11%s] "
+                      "probe status: %u:%u "
+                      "(TSF: 0x%08X:%08X) - %d "
+                      "elapsed=%lu usec\n",
+                      notif->channel,
+                      notif->band ? "bg" : "a",
+                      notif->probe_status, notif->num_probe_not_sent,
+                      le32_to_cpu(notif->tsf_high),
+                      le32_to_cpu(notif->tsf_low),
+                      le32_to_cpu(notif->statistics[0]),
+                      le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
+#endif
+       return 0;
+}
+
+/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
+static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
+                                      struct iwl_rx_cmd_buffer *rxb,
+                                      struct iwl_device_cmd *cmd)
+{
+       struct iwl_rx_packet *pkt = rxb_addr(rxb);
+       struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
+
+       IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
+                      scan_notif->scanned_channels,
+                      scan_notif->tsf_low,
+                      scan_notif->tsf_high, scan_notif->status);
+
+       IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
+                      (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
+                      jiffies_to_msecs(jiffies - priv->scan_start));
+
+       /*
+        * When aborting, we run the scan completed background work inline
+        * and the background work must then do nothing. The SCAN_COMPLETE
+        * bit helps implement that logic and thus needs to be set before
+        * queueing the work. Also, since the scan abort waits for SCAN_HW
+        * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
+        * to avoid a race there.
+        */
+       set_bit(STATUS_SCAN_COMPLETE, &priv->status);
+       clear_bit(STATUS_SCAN_HW, &priv->status);
+       queue_work(priv->workqueue, &priv->scan_completed);
+
+       if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
+           iwl_advanced_bt_coexist(priv) &&
+           priv->bt_status != scan_notif->bt_status) {
+               if (scan_notif->bt_status) {
+                       /* BT on */
+                       if (!priv->bt_ch_announce)
+                               priv->bt_traffic_load =
+                                       IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
+                       /*
+                        * otherwise, no traffic load information provided
+                        * no changes made
+                        */
+               } else {
+                       /* BT off */
+                       priv->bt_traffic_load =
+                               IWL_BT_COEX_TRAFFIC_LOAD_NONE;
+               }
+               priv->bt_status = scan_notif->bt_status;
+               queue_work(priv->workqueue,
+                          &priv->bt_traffic_change_work);
+       }
+       return 0;
+}
+
+void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
+{
+       /* scan handlers */
+       priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
+       priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
+       priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
+                                       iwl_rx_scan_results_notif;
+       priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
+                                       iwl_rx_scan_complete_notif;
+}
+
+static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
+                                    enum ieee80211_band band, u8 n_probes)
+{
+       if (band == IEEE80211_BAND_5GHZ)
+               return IWL_ACTIVE_DWELL_TIME_52 +
+                       IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
+       else
+               return IWL_ACTIVE_DWELL_TIME_24 +
+                       IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
+}
+
+static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
+{
+       struct iwl_rxon_context *ctx;
+       int limits[NUM_IWL_RXON_CTX] = {};
+       int n_active = 0;
+       u16 limit;
+
+       BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
+
+       /*
+        * If we're associated, we clamp the dwell time 98%
+        * of the beacon interval (minus 2 * channel tune time)
+        * If both contexts are active, we have to restrict to
+        * 1/2 of the minimum of them, because they might be in
+        * lock-step with the time inbetween only half of what
+        * time we'd have in each of them.
+        */
+       for_each_context(priv, ctx) {
+               switch (ctx->staging.dev_type) {
+               case RXON_DEV_TYPE_P2P:
+                       /* no timing constraints */
+                       continue;
+               case RXON_DEV_TYPE_ESS:
+               default:
+                       /* timing constraints if associated */
+                       if (!iwl_is_associated_ctx(ctx))
+                               continue;
+                       break;
+               case RXON_DEV_TYPE_CP:
+               case RXON_DEV_TYPE_2STA:
+                       /*
+                        * These seem to always have timers for TBTT
+                        * active in uCode even when not associated yet.
+                        */
+                       break;
+               }
+
+               limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
+       }
+
+       switch (n_active) {
+       case 0:
+               return dwell_time;
+       case 2:
+               limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
+               limit /= 2;
+               dwell_time = min(limit, dwell_time);
+               /* fall through to limit further */
+       case 1:
+               limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
+               limit /= n_active;
+               return min(limit, dwell_time);
+       default:
+               WARN_ON_ONCE(1);
+               return dwell_time;
+       }
+}
+
+static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
+                                     enum ieee80211_band band)
+{
+       u16 passive = (band == IEEE80211_BAND_2GHZ) ?
+           IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
+           IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
+
+       return iwl_limit_dwell(priv, passive);
+}
+
+/* Return valid, unused, channel for a passive scan to reset the RF */
+static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
+                                       enum ieee80211_band band)
+{
+       struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
+       struct iwl_rxon_context *ctx;
+       int i;
+
+       for (i = 0; i < sband->n_channels; i++) {
+               bool busy = false;
+
+               for_each_context(priv, ctx) {
+                       busy = sband->channels[i].hw_value ==
+                               le16_to_cpu(ctx->staging.channel);
+                       if (busy)
+                               break;
+               }
+
+               if (busy)
+                       continue;
+
+               if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
+                       return sband->channels[i].hw_value;
+       }
+
+       return 0;
+}
+
+static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
+                                         struct ieee80211_vif *vif,
+                                         enum ieee80211_band band,
+                                         struct iwl_scan_channel *scan_ch)
+{
+       const struct ieee80211_supported_band *sband;
+       u16 channel;
+
+       sband = iwl_get_hw_mode(priv, band);
+       if (!sband) {
+               IWL_ERR(priv, "invalid band\n");
+               return 0;
+       }
+
+       channel = iwl_get_single_channel_number(priv, band);
+       if (channel) {
+               scan_ch->channel = cpu_to_le16(channel);
+               scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+               scan_ch->active_dwell =
+                       cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+               scan_ch->passive_dwell =
+                       cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+               /* Set txpower levels to defaults */
+               scan_ch->dsp_atten = 110;
+               if (band == IEEE80211_BAND_5GHZ)
+                       scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+               else
+                       scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+               return 1;
+       }
+
+       IWL_ERR(priv, "no valid channel found\n");
+       return 0;
+}
+
+static int iwl_get_channels_for_scan(struct iwl_priv *priv,
+                                    struct ieee80211_vif *vif,
+                                    enum ieee80211_band band,
+                                    u8 is_active, u8 n_probes,
+                                    struct iwl_scan_channel *scan_ch)
+{
+       struct ieee80211_channel *chan;
+       const struct ieee80211_supported_band *sband;
+       u16 passive_dwell = 0;
+       u16 active_dwell = 0;
+       int added, i;
+       u16 channel;
+
+       sband = iwl_get_hw_mode(priv, band);
+       if (!sband)
+               return 0;
+
+       active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
+       passive_dwell = iwl_get_passive_dwell_time(priv, band);
+
+       if (passive_dwell <= active_dwell)
+               passive_dwell = active_dwell + 1;
+
+       for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
+               chan = priv->scan_request->channels[i];
+
+               if (chan->band != band)
+                       continue;
+
+               channel = chan->hw_value;
+               scan_ch->channel = cpu_to_le16(channel);
+
+               if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
+                       scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+               else
+                       scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
+
+               if (n_probes)
+                       scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
+
+               scan_ch->active_dwell = cpu_to_le16(active_dwell);
+               scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+
+               /* Set txpower levels to defaults */
+               scan_ch->dsp_atten = 110;
+
+               /* NOTE: if we were doing 6Mb OFDM for scans we'd use
+                * power level:
+                * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
+                */
+               if (band == IEEE80211_BAND_5GHZ)
+                       scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+               else
+                       scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+
+               IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
+                              channel, le32_to_cpu(scan_ch->type),
+                              (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+                               "ACTIVE" : "PASSIVE",
+                              (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+                              active_dwell : passive_dwell);
+
+               scan_ch++;
+               added++;
+       }
+
+       IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
+       return added;
+}
+
+/**
+ * iwl_fill_probe_req - fill in all required fields and IE for probe request
+ */
+
+static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
+                             const u8 *ies, int ie_len, const u8 *ssid,
+                             u8 ssid_len, int left)
+{
+       int len = 0;
+       u8 *pos = NULL;
+
+       /* Make sure there is enough space for the probe request,
+        * two mandatory IEs and the data */
+       left -= 24;
+       if (left < 0)
+               return 0;
+
+       frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
+       eth_broadcast_addr(frame->da);
+       memcpy(frame->sa, ta, ETH_ALEN);
+       eth_broadcast_addr(frame->bssid);
+       frame->seq_ctrl = 0;
+
+       len += 24;
+
+       /* ...next IE... */
+       pos = &frame->u.probe_req.variable[0];
+
+       /* fill in our SSID IE */
+       left -= ssid_len + 2;
+       if (left < 0)
+               return 0;
+       *pos++ = WLAN_EID_SSID;
+       *pos++ = ssid_len;
+       if (ssid && ssid_len) {
+               memcpy(pos, ssid, ssid_len);
+               pos += ssid_len;
+       }
+
+       len += ssid_len + 2;
+
+       if (WARN_ON(left < ie_len))
+               return len;
+
+       if (ies && ie_len) {
+               memcpy(pos, ies, ie_len);
+               len += ie_len;
+       }
+
+       return (u16)len;
+}
+
+static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
+{
+       struct iwl_host_cmd cmd = {
+               .id = REPLY_SCAN_CMD,
+               .len = { sizeof(struct iwl_scan_cmd), },
+       };
+       struct iwl_scan_cmd *scan;
+       struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
+       u32 rate_flags = 0;
+       u16 cmd_len = 0;
+       u16 rx_chain = 0;
+       enum ieee80211_band band;
+       u8 n_probes = 0;
+       u8 rx_ant = priv->nvm_data->valid_rx_ant;
+       u8 rate;
+       bool is_active = false;
+       int  chan_mod;
+       u8 active_chains;
+       u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
+       int ret;
+       int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
+                           MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
+                           priv->fw->ucode_capa.max_probe_length;
+       const u8 *ssid = NULL;
+       u8 ssid_len = 0;
+
+       if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
+                   (!priv->scan_request ||
+                    priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
+               return -EINVAL;
+
+       lockdep_assert_held(&priv->mutex);
+
+       if (vif)
+               ctx = iwl_rxon_ctx_from_vif(vif);
+
+       if (!priv->scan_cmd) {
+               priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
+               if (!priv->scan_cmd) {
+                       IWL_DEBUG_SCAN(priv,
+                                      "fail to allocate memory for scan\n");
+                       return -ENOMEM;
+               }
+       }
+       scan = priv->scan_cmd;
+       memset(scan, 0, scan_cmd_size);
+
+       scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
+       scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
+
+       if (iwl_is_any_associated(priv)) {
+               u16 interval = 0;
+               u32 extra;
+               u32 suspend_time = 100;
+               u32 scan_suspend_time = 100;
+
+               IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
+               switch (priv->scan_type) {
+               case IWL_SCAN_RADIO_RESET:
+                       interval = 0;
+                       break;
+               case IWL_SCAN_NORMAL:
+                       interval = vif->bss_conf.beacon_int;
+                       break;
+               }
+
+               scan->suspend_time = 0;
+               scan->max_out_time = cpu_to_le32(200 * 1024);
+               if (!interval)
+                       interval = suspend_time;
+
+               extra = (suspend_time / interval) << 22;
+               scan_suspend_time = (extra |
+                   ((suspend_time % interval) * 1024));
+               scan->suspend_time = cpu_to_le32(scan_suspend_time);
+               IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
+                              scan_suspend_time, interval);
+       }
+
+       switch (priv->scan_type) {
+       case IWL_SCAN_RADIO_RESET:
+               IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
+               /*
+                * Override quiet time as firmware checks that active
+                * dwell is >= quiet; since we use passive scan it'll
+                * not actually be used.
+                */
+               scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+               break;
+       case IWL_SCAN_NORMAL:
+               if (priv->scan_request->n_ssids) {
+                       int i, p = 0;
+                       IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
+                       /*
+                        * The highest priority SSID is inserted to the
+                        * probe request template.
+                        */
+                       ssid_len = priv->scan_request->ssids[0].ssid_len;
+                       ssid = priv->scan_request->ssids[0].ssid;
+
+                       /*
+                        * Invert the order of ssids, the firmware will invert
+                        * it back.
+                        */
+                       for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
+                               scan->direct_scan[p].id = WLAN_EID_SSID;
+                               scan->direct_scan[p].len =
+                                       priv->scan_request->ssids[i].ssid_len;
+                               memcpy(scan->direct_scan[p].ssid,
+                                      priv->scan_request->ssids[i].ssid,
+                                      priv->scan_request->ssids[i].ssid_len);
+                               n_probes++;
+                               p++;
+                       }
+                       is_active = true;
+               } else
+                       IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
+               break;
+       }
+
+       scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
+       scan->tx_cmd.sta_id = ctx->bcast_sta_id;
+       scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+
+       switch (priv->scan_band) {
+       case IEEE80211_BAND_2GHZ:
+               scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
+               chan_mod = le32_to_cpu(
+                       priv->contexts[IWL_RXON_CTX_BSS].active.flags &
+                                               RXON_FLG_CHANNEL_MODE_MSK)
+                                      >> RXON_FLG_CHANNEL_MODE_POS;
+               if ((priv->scan_request && priv->scan_request->no_cck) ||
+                   chan_mod == CHANNEL_MODE_PURE_40) {
+                       rate = IWL_RATE_6M_PLCP;
+               } else {
+                       rate = IWL_RATE_1M_PLCP;
+                       rate_flags = RATE_MCS_CCK_MSK;
+               }
+               /*
+                * Internal scans are passive, so we can indiscriminately set
+                * the BT ignore flag on 2.4 GHz since it applies to TX only.
+                */
+               if (priv->lib->bt_params &&
+                   priv->lib->bt_params->advanced_bt_coexist)
+                       scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
+               break;
+       case IEEE80211_BAND_5GHZ:
+               rate = IWL_RATE_6M_PLCP;
+               break;
+       default:
+               IWL_WARN(priv, "Invalid scan band\n");
+               return -EIO;
+       }
+
+       /*
+        * If active scanning is requested but a certain channel is
+        * marked passive, we can do active scanning if we detect
+        * transmissions.
+        *
+        * There is an issue with some firmware versions that triggers
+        * a sysassert on a "good CRC threshold" of zero (== disabled),
+        * on a radar channel even though this means that we should NOT
+        * send probes.
+        *
+        * The "good CRC threshold" is the number of frames that we
+        * need to receive during our dwell time on a channel before
+        * sending out probes -- setting this to a huge value will
+        * mean we never reach it, but at the same time work around
+        * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
+        * here instead of IWL_GOOD_CRC_TH_DISABLED.
+        *
+        * This was fixed in later versions along with some other
+        * scan changes, and the threshold behaves as a flag in those
+        * versions.
+        */
+       if (priv->new_scan_threshold_behaviour)
+               scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+                                               IWL_GOOD_CRC_TH_DISABLED;
+       else
+               scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+                                               IWL_GOOD_CRC_TH_NEVER;
+
+       band = priv->scan_band;
+
+       if (band == IEEE80211_BAND_2GHZ &&
+           priv->lib->bt_params &&
+           priv->lib->bt_params->advanced_bt_coexist) {
+               /* transmit 2.4 GHz probes only on first antenna */
+               scan_tx_antennas = first_antenna(scan_tx_antennas);
+       }
+
+       priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
+                                                   priv->scan_tx_ant[band],
+                                                   scan_tx_antennas);
+       rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
+       scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
+
+       /*
+        * In power save mode while associated use one chain,
+        * otherwise use all chains
+        */
+       if (test_bit(STATUS_POWER_PMI, &priv->status) &&
+           !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
+               /* rx_ant has been set to all valid chains previously */
+               active_chains = rx_ant &
+                               ((u8)(priv->chain_noise_data.active_chains));
+               if (!active_chains)
+                       active_chains = rx_ant;
+
+               IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
+                               priv->chain_noise_data.active_chains);
+
+               rx_ant = first_antenna(active_chains);
+       }
+       if (priv->lib->bt_params &&
+           priv->lib->bt_params->advanced_bt_coexist &&
+           priv->bt_full_concurrent) {
+               /* operated as 1x1 in full concurrency mode */
+               rx_ant = first_antenna(rx_ant);
+       }
+
+       /* MIMO is not used here, but value is required */
+       rx_chain |=
+               priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
+       rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
+       rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
+       rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
+       scan->rx_chain = cpu_to_le16(rx_chain);
+       switch (priv->scan_type) {
+       case IWL_SCAN_NORMAL:
+               cmd_len = iwl_fill_probe_req(
+                                       (struct ieee80211_mgmt *)scan->data,
+                                       vif->addr,
+                                       priv->scan_request->ie,
+                                       priv->scan_request->ie_len,
+                                       ssid, ssid_len,
+                                       scan_cmd_size - sizeof(*scan));
+               break;
+       case IWL_SCAN_RADIO_RESET:
+               /* use bcast addr, will not be transmitted but must be valid */
+               cmd_len = iwl_fill_probe_req(
+                                       (struct ieee80211_mgmt *)scan->data,
+                                       iwl_bcast_addr, NULL, 0,
+                                       NULL, 0,
+                                       scan_cmd_size - sizeof(*scan));
+               break;
+       default:
+               BUG();
+       }
+       scan->tx_cmd.len = cpu_to_le16(cmd_len);
+
+       scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
+                              RXON_FILTER_BCON_AWARE_MSK);
+
+       switch (priv->scan_type) {
+       case IWL_SCAN_RADIO_RESET:
+               scan->channel_count =
+                       iwl_get_channel_for_reset_scan(priv, vif, band,
+                               (void *)&scan->data[cmd_len]);
+               break;
+       case IWL_SCAN_NORMAL:
+               scan->channel_count =
+                       iwl_get_channels_for_scan(priv, vif, band,
+                               is_active, n_probes,
+                               (void *)&scan->data[cmd_len]);
+               break;
+       }
+
+       if (scan->channel_count == 0) {
+               IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
+               return -EIO;
+       }
+
+       cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
+           scan->channel_count * sizeof(struct iwl_scan_channel);
+       cmd.data[0] = scan;
+       cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
+       scan->len = cpu_to_le16(cmd.len[0]);
+
+       /* set scan bit here for PAN params */
+       set_bit(STATUS_SCAN_HW, &priv->status);
+
+       ret = iwlagn_set_pan_params(priv);
+       if (ret) {
+               clear_bit(STATUS_SCAN_HW, &priv->status);
+               return ret;
+       }
+
+       ret = iwl_dvm_send_cmd(priv, &cmd);
+       if (ret) {
+               clear_bit(STATUS_SCAN_HW, &priv->status);
+               iwlagn_set_pan_params(priv);
+       }
+
+       return ret;
+}
+
+void iwl_init_scan_params(struct iwl_priv *priv)
+{
+       u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
+       if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
+               priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
+       if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
+               priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
+}
+
+int __must_check iwl_scan_initiate(struct iwl_priv *priv,
+                                  struct ieee80211_vif *vif,
+                                  enum iwl_scan_type scan_type,
+                                  enum ieee80211_band band)
+{
+       int ret;
+
+       lockdep_assert_held(&priv->mutex);
+
+       cancel_delayed_work(&priv->scan_check);
+
+       if (!iwl_is_ready_rf(priv)) {
+               IWL_WARN(priv, "Request scan called when driver not ready.\n");
+               return -EIO;
+       }
+
+       if (test_bit(STATUS_SCAN_HW, &priv->status)) {
+               IWL_DEBUG_SCAN(priv,
+                       "Multiple concurrent scan requests in parallel.\n");
+               return -EBUSY;
+       }
+
+       if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
+               return -EBUSY;
+       }
+
+       IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
+                       scan_type == IWL_SCAN_NORMAL ? "" :
+                       "internal short ");
+
+       set_bit(STATUS_SCANNING, &priv->status);
+       priv->scan_type = scan_type;
+       priv->scan_start = jiffies;
+       priv->scan_band = band;
+
+       ret = iwlagn_request_scan(priv, vif);
+       if (ret) {
+               clear_bit(STATUS_SCANNING, &priv->status);
+               priv->scan_type = IWL_SCAN_NORMAL;
+               return ret;
+       }
+
+       queue_delayed_work(priv->workqueue, &priv->scan_check,
+                          IWL_SCAN_CHECK_WATCHDOG);
+
+       return 0;
+}
+
+
+/*
+ * internal short scan, this function should only been called while associated.
+ * It will reset and tune the radio to prevent possible RF related problem
+ */
+void iwl_internal_short_hw_scan(struct iwl_priv *priv)
+{
+       queue_work(priv->workqueue, &priv->start_internal_scan);
+}
+
+static void iwl_bg_start_internal_scan(struct work_struct *work)
+{
+       struct iwl_priv *priv =
+               container_of(work, struct iwl_priv, start_internal_scan);
+
+       IWL_DEBUG_SCAN(priv, "Start internal scan\n");
+
+       mutex_lock(&priv->mutex);
+
+       if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
+               IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
+               goto unlock;
+       }
+
+       if (test_bit(STATUS_SCANNING, &priv->status)) {
+               IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
+               goto unlock;
+       }
+
+       if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
+               IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
+ unlock:
+       mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_scan_check(struct work_struct *data)
+{
+       struct iwl_priv *priv =
+           container_of(data, struct iwl_priv, scan_check.work);
+
+       IWL_DEBUG_SCAN(priv, "Scan check work\n");
+
+       /* Since we are here firmware does not finish scan and
+        * most likely is in bad shape, so we don't bother to
+        * send abort command, just force scan complete to mac80211 */
+       mutex_lock(&priv->mutex);
+       iwl_force_scan_end(priv);
+       mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_abort_scan(struct work_struct *work)
+{
+       struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
+
+       IWL_DEBUG_SCAN(priv, "Abort scan work\n");
+
+       /* We keep scan_check work queued in case when firmware will not
+        * report back scan completed notification */
+       mutex_lock(&priv->mutex);
+       iwl_scan_cancel_timeout(priv, 200);
+       mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_scan_completed(struct work_struct *work)
+{
+       struct iwl_priv *priv =
+               container_of(work, struct iwl_priv, scan_completed);
+
+       mutex_lock(&priv->mutex);
+       iwl_process_scan_complete(priv);
+       mutex_unlock(&priv->mutex);
+}
+
+void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
+{
+       INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
+       INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
+       INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
+       INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
+}
+
+void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
+{
+       cancel_work_sync(&priv->start_internal_scan);
+       cancel_work_sync(&priv->abort_scan);
+       cancel_work_sync(&priv->scan_completed);
+
+       if (cancel_delayed_work_sync(&priv->scan_check)) {
+               mutex_lock(&priv->mutex);
+               iwl_force_scan_end(priv);
+               mutex_unlock(&priv->mutex);
+       }
+}