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  1/******************************************************************************
  2 *
  3 * GPL LICENSE SUMMARY
  4 *
  5 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of version 2 of the GNU General Public License as
  9 * published by the Free Software Foundation.
 10 *
 11 * This program is distributed in the hope that it will be useful, but
 12 * WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14 * General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 19 * USA
 20 *
 21 * The full GNU General Public License is included in this distribution
 22 * in the file called LICENSE.GPL.
 23 *
 24 * Contact Information:
 25 *  Intel Linux Wireless <ilw@linux.intel.com>
 26 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 27 *****************************************************************************/
 28#include <linux/slab.h>
 29#include <linux/types.h>
 30#include <linux/etherdevice.h>
 31#include <net/mac80211.h>
 32
 33#include "iwl-eeprom.h"
 34#include "iwl-dev.h"
 35#include "iwl-core.h"
 36#include "iwl-sta.h"
 37#include "iwl-io.h"
 38#include "iwl-helpers.h"
 39
 40/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
 41 * sending probe req.  This should be set long enough to hear probe responses
 42 * from more than one AP.  */
 43#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
 44#define IWL_ACTIVE_DWELL_TIME_52    (20)
 45
 46#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
 47#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
 48
 49/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
 50 * Must be set longer than active dwell time.
 51 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
 52#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
 53#define IWL_PASSIVE_DWELL_TIME_52   (10)
 54#define IWL_PASSIVE_DWELL_BASE      (100)
 55#define IWL_CHANNEL_TUNE_TIME       5
 56
 57static int iwl_legacy_send_scan_abort(struct iwl_priv *priv)
 58{
 59	int ret;
 60	struct iwl_rx_packet *pkt;
 61	struct iwl_host_cmd cmd = {
 62		.id = REPLY_SCAN_ABORT_CMD,
 63		.flags = CMD_WANT_SKB,
 64	};
 65
 66	/* Exit instantly with error when device is not ready
 67	 * to receive scan abort command or it does not perform
 68	 * hardware scan currently */
 69	if (!test_bit(STATUS_READY, &priv->status) ||
 70	    !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
 71	    !test_bit(STATUS_SCAN_HW, &priv->status) ||
 72	    test_bit(STATUS_FW_ERROR, &priv->status) ||
 73	    test_bit(STATUS_EXIT_PENDING, &priv->status))
 74		return -EIO;
 75
 76	ret = iwl_legacy_send_cmd_sync(priv, &cmd);
 77	if (ret)
 78		return ret;
 79
 80	pkt = (struct iwl_rx_packet *)cmd.reply_page;
 81	if (pkt->u.status != CAN_ABORT_STATUS) {
 82		/* The scan abort will return 1 for success or
 83		 * 2 for "failure".  A failure condition can be
 84		 * due to simply not being in an active scan which
 85		 * can occur if we send the scan abort before we
 86		 * the microcode has notified us that a scan is
 87		 * completed. */
 88		IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
 89		ret = -EIO;
 90	}
 91
 92	iwl_legacy_free_pages(priv, cmd.reply_page);
 93	return ret;
 94}
 95
 96static void iwl_legacy_complete_scan(struct iwl_priv *priv, bool aborted)
 97{
 98	/* check if scan was requested from mac80211 */
 99	if (priv->scan_request) {
100		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
101		ieee80211_scan_completed(priv->hw, aborted);
102	}
103
104	priv->scan_vif = NULL;
105	priv->scan_request = NULL;
106}
107
108void iwl_legacy_force_scan_end(struct iwl_priv *priv)
109{
110	lockdep_assert_held(&priv->mutex);
111
112	if (!test_bit(STATUS_SCANNING, &priv->status)) {
113		IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
114		return;
115	}
116
117	IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
118	clear_bit(STATUS_SCANNING, &priv->status);
119	clear_bit(STATUS_SCAN_HW, &priv->status);
120	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
121	iwl_legacy_complete_scan(priv, true);
122}
123
124static void iwl_legacy_do_scan_abort(struct iwl_priv *priv)
125{
126	int ret;
127
128	lockdep_assert_held(&priv->mutex);
129
130	if (!test_bit(STATUS_SCANNING, &priv->status)) {
131		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
132		return;
133	}
134
135	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
136		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
137		return;
138	}
139
140	ret = iwl_legacy_send_scan_abort(priv);
141	if (ret) {
142		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
143		iwl_legacy_force_scan_end(priv);
144	} else
145		IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
146}
147
148/**
149 * iwl_scan_cancel - Cancel any currently executing HW scan
150 */
151int iwl_legacy_scan_cancel(struct iwl_priv *priv)
152{
153	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
154	queue_work(priv->workqueue, &priv->abort_scan);
155	return 0;
156}
157EXPORT_SYMBOL(iwl_legacy_scan_cancel);
158
159/**
160 * iwl_legacy_scan_cancel_timeout - Cancel any currently executing HW scan
161 * @ms: amount of time to wait (in milliseconds) for scan to abort
162 *
163 */
164int iwl_legacy_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
165{
166	unsigned long timeout = jiffies + msecs_to_jiffies(ms);
167
168	lockdep_assert_held(&priv->mutex);
169
170	IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
171
172	iwl_legacy_do_scan_abort(priv);
173
174	while (time_before_eq(jiffies, timeout)) {
175		if (!test_bit(STATUS_SCAN_HW, &priv->status))
176			break;
177		msleep(20);
178	}
179
180	return test_bit(STATUS_SCAN_HW, &priv->status);
181}
182EXPORT_SYMBOL(iwl_legacy_scan_cancel_timeout);
183
184/* Service response to REPLY_SCAN_CMD (0x80) */
185static void iwl_legacy_rx_reply_scan(struct iwl_priv *priv,
186			      struct iwl_rx_mem_buffer *rxb)
187{
188#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
189	struct iwl_rx_packet *pkt = rxb_addr(rxb);
190	struct iwl_scanreq_notification *notif =
191	    (struct iwl_scanreq_notification *)pkt->u.raw;
192
193	IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
194#endif
195}
196
197/* Service SCAN_START_NOTIFICATION (0x82) */
198static void iwl_legacy_rx_scan_start_notif(struct iwl_priv *priv,
199				    struct iwl_rx_mem_buffer *rxb)
200{
201	struct iwl_rx_packet *pkt = rxb_addr(rxb);
202	struct iwl_scanstart_notification *notif =
203	    (struct iwl_scanstart_notification *)pkt->u.raw;
204	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
205	IWL_DEBUG_SCAN(priv, "Scan start: "
206		       "%d [802.11%s] "
207		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
208		       notif->channel,
209		       notif->band ? "bg" : "a",
210		       le32_to_cpu(notif->tsf_high),
211		       le32_to_cpu(notif->tsf_low),
212		       notif->status, notif->beacon_timer);
213}
214
215/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
216static void iwl_legacy_rx_scan_results_notif(struct iwl_priv *priv,
217				      struct iwl_rx_mem_buffer *rxb)
218{
219#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
220	struct iwl_rx_packet *pkt = rxb_addr(rxb);
221	struct iwl_scanresults_notification *notif =
222	    (struct iwl_scanresults_notification *)pkt->u.raw;
223
224	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
225		       "%d [802.11%s] "
226		       "(TSF: 0x%08X:%08X) - %d "
227		       "elapsed=%lu usec\n",
228		       notif->channel,
229		       notif->band ? "bg" : "a",
230		       le32_to_cpu(notif->tsf_high),
231		       le32_to_cpu(notif->tsf_low),
232		       le32_to_cpu(notif->statistics[0]),
233		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
234#endif
235}
236
237/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
238static void iwl_legacy_rx_scan_complete_notif(struct iwl_priv *priv,
239				       struct iwl_rx_mem_buffer *rxb)
240{
241
242#ifdef CONFIG_IWLWIFI_LEGACY_DEBUG
243	struct iwl_rx_packet *pkt = rxb_addr(rxb);
244	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
245#endif
246
247	IWL_DEBUG_SCAN(priv,
248			"Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
249		       scan_notif->scanned_channels,
250		       scan_notif->tsf_low,
251		       scan_notif->tsf_high, scan_notif->status);
252
253	/* The HW is no longer scanning */
254	clear_bit(STATUS_SCAN_HW, &priv->status);
255
256	IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
257		       (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
258		       jiffies_to_msecs(jiffies - priv->scan_start));
259
260	queue_work(priv->workqueue, &priv->scan_completed);
261}
262
263void iwl_legacy_setup_rx_scan_handlers(struct iwl_priv *priv)
264{
265	/* scan handlers */
266	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_legacy_rx_reply_scan;
267	priv->rx_handlers[SCAN_START_NOTIFICATION] =
268					iwl_legacy_rx_scan_start_notif;
269	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
270					iwl_legacy_rx_scan_results_notif;
271	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
272					iwl_legacy_rx_scan_complete_notif;
273}
274EXPORT_SYMBOL(iwl_legacy_setup_rx_scan_handlers);
275
276inline u16 iwl_legacy_get_active_dwell_time(struct iwl_priv *priv,
277				     enum ieee80211_band band,
278				     u8 n_probes)
279{
280	if (band == IEEE80211_BAND_5GHZ)
281		return IWL_ACTIVE_DWELL_TIME_52 +
282			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
283	else
284		return IWL_ACTIVE_DWELL_TIME_24 +
285			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
286}
287EXPORT_SYMBOL(iwl_legacy_get_active_dwell_time);
288
289u16 iwl_legacy_get_passive_dwell_time(struct iwl_priv *priv,
290			       enum ieee80211_band band,
291			       struct ieee80211_vif *vif)
292{
293	struct iwl_rxon_context *ctx;
294	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
295	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
296	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
297
298	if (iwl_legacy_is_any_associated(priv)) {
299		/*
300		 * If we're associated, we clamp the maximum passive
301		 * dwell time to be 98% of the smallest beacon interval
302		 * (minus 2 * channel tune time)
303		 */
304		for_each_context(priv, ctx) {
305			u16 value;
306
307			if (!iwl_legacy_is_associated_ctx(ctx))
308				continue;
309			value = ctx->vif ? ctx->vif->bss_conf.beacon_int : 0;
310			if ((value > IWL_PASSIVE_DWELL_BASE) || !value)
311				value = IWL_PASSIVE_DWELL_BASE;
312			value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
313			passive = min(value, passive);
314		}
315	}
316
317	return passive;
318}
319EXPORT_SYMBOL(iwl_legacy_get_passive_dwell_time);
320
321void iwl_legacy_init_scan_params(struct iwl_priv *priv)
322{
323	u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
324	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
325		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
326	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
327		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
328}
329EXPORT_SYMBOL(iwl_legacy_init_scan_params);
330
331static int iwl_legacy_scan_initiate(struct iwl_priv *priv,
332				    struct ieee80211_vif *vif)
333{
334	int ret;
335
336	lockdep_assert_held(&priv->mutex);
337
338	if (WARN_ON(!priv->cfg->ops->utils->request_scan))
339		return -EOPNOTSUPP;
340
341	cancel_delayed_work(&priv->scan_check);
342
343	if (!iwl_legacy_is_ready_rf(priv)) {
344		IWL_WARN(priv, "Request scan called when driver not ready.\n");
345		return -EIO;
346	}
347
348	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
349		IWL_DEBUG_SCAN(priv,
350			"Multiple concurrent scan requests in parallel.\n");
351		return -EBUSY;
352	}
353
354	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
355		IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
356		return -EBUSY;
357	}
358
359	IWL_DEBUG_SCAN(priv, "Starting scan...\n");
360
361	set_bit(STATUS_SCANNING, &priv->status);
362	priv->scan_start = jiffies;
363
364	ret = priv->cfg->ops->utils->request_scan(priv, vif);
365	if (ret) {
366		clear_bit(STATUS_SCANNING, &priv->status);
367		return ret;
368	}
369
370	queue_delayed_work(priv->workqueue, &priv->scan_check,
371			   IWL_SCAN_CHECK_WATCHDOG);
372
373	return 0;
374}
375
376int iwl_legacy_mac_hw_scan(struct ieee80211_hw *hw,
377		    struct ieee80211_vif *vif,
378		    struct cfg80211_scan_request *req)
379{
380	struct iwl_priv *priv = hw->priv;
381	int ret;
382
383	IWL_DEBUG_MAC80211(priv, "enter\n");
384
385	if (req->n_channels == 0)
386		return -EINVAL;
387
388	mutex_lock(&priv->mutex);
389
390	if (test_bit(STATUS_SCANNING, &priv->status)) {
391		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
392		ret = -EAGAIN;
393		goto out_unlock;
394	}
395
396	/* mac80211 will only ask for one band at a time */
397	priv->scan_request = req;
398	priv->scan_vif = vif;
399	priv->scan_band = req->channels[0]->band;
400
401	ret = iwl_legacy_scan_initiate(priv, vif);
402
403	IWL_DEBUG_MAC80211(priv, "leave\n");
404
405out_unlock:
406	mutex_unlock(&priv->mutex);
407
408	return ret;
409}
410EXPORT_SYMBOL(iwl_legacy_mac_hw_scan);
411
412static void iwl_legacy_bg_scan_check(struct work_struct *data)
413{
414	struct iwl_priv *priv =
415	    container_of(data, struct iwl_priv, scan_check.work);
416
417	IWL_DEBUG_SCAN(priv, "Scan check work\n");
418
419	/* Since we are here firmware does not finish scan and
420	 * most likely is in bad shape, so we don't bother to
421	 * send abort command, just force scan complete to mac80211 */
422	mutex_lock(&priv->mutex);
423	iwl_legacy_force_scan_end(priv);
424	mutex_unlock(&priv->mutex);
425}
426
427/**
428 * iwl_legacy_fill_probe_req - fill in all required fields and IE for probe request
429 */
430
431u16
432iwl_legacy_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
433		       const u8 *ta, const u8 *ies, int ie_len, int left)
434{
435	int len = 0;
436	u8 *pos = NULL;
437
438	/* Make sure there is enough space for the probe request,
439	 * two mandatory IEs and the data */
440	left -= 24;
441	if (left < 0)
442		return 0;
443
444	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
445	memcpy(frame->da, iwlegacy_bcast_addr, ETH_ALEN);
446	memcpy(frame->sa, ta, ETH_ALEN);
447	memcpy(frame->bssid, iwlegacy_bcast_addr, ETH_ALEN);
448	frame->seq_ctrl = 0;
449
450	len += 24;
451
452	/* ...next IE... */
453	pos = &frame->u.probe_req.variable[0];
454
455	/* fill in our indirect SSID IE */
456	left -= 2;
457	if (left < 0)
458		return 0;
459	*pos++ = WLAN_EID_SSID;
460	*pos++ = 0;
461
462	len += 2;
463
464	if (WARN_ON(left < ie_len))
465		return len;
466
467	if (ies && ie_len) {
468		memcpy(pos, ies, ie_len);
469		len += ie_len;
470	}
471
472	return (u16)len;
473}
474EXPORT_SYMBOL(iwl_legacy_fill_probe_req);
475
476static void iwl_legacy_bg_abort_scan(struct work_struct *work)
477{
478	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
479
480	IWL_DEBUG_SCAN(priv, "Abort scan work\n");
481
482	/* We keep scan_check work queued in case when firmware will not
483	 * report back scan completed notification */
484	mutex_lock(&priv->mutex);
485	iwl_legacy_scan_cancel_timeout(priv, 200);
486	mutex_unlock(&priv->mutex);
487}
488
489static void iwl_legacy_bg_scan_completed(struct work_struct *work)
490{
491	struct iwl_priv *priv =
492	    container_of(work, struct iwl_priv, scan_completed);
493	bool aborted;
494
495	IWL_DEBUG_SCAN(priv, "Completed scan.\n");
496
497	cancel_delayed_work(&priv->scan_check);
498
499	mutex_lock(&priv->mutex);
500
501	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
502	if (aborted)
503		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
504
505	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
506		IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
507		goto out_settings;
508	}
509
510	iwl_legacy_complete_scan(priv, aborted);
511
512out_settings:
513	/* Can we still talk to firmware ? */
514	if (!iwl_legacy_is_ready_rf(priv))
515		goto out;
516
517	/*
518	 * We do not commit power settings while scan is pending,
519	 * do it now if the settings changed.
520	 */
521	iwl_legacy_power_set_mode(priv, &priv->power_data.sleep_cmd_next, false);
522	iwl_legacy_set_tx_power(priv, priv->tx_power_next, false);
523
524	priv->cfg->ops->utils->post_scan(priv);
525
526out:
527	mutex_unlock(&priv->mutex);
528}
529
530void iwl_legacy_setup_scan_deferred_work(struct iwl_priv *priv)
531{
532	INIT_WORK(&priv->scan_completed, iwl_legacy_bg_scan_completed);
533	INIT_WORK(&priv->abort_scan, iwl_legacy_bg_abort_scan);
534	INIT_DELAYED_WORK(&priv->scan_check, iwl_legacy_bg_scan_check);
535}
536EXPORT_SYMBOL(iwl_legacy_setup_scan_deferred_work);
537
538void iwl_legacy_cancel_scan_deferred_work(struct iwl_priv *priv)
539{
540	cancel_work_sync(&priv->abort_scan);
541	cancel_work_sync(&priv->scan_completed);
542
543	if (cancel_delayed_work_sync(&priv->scan_check)) {
544		mutex_lock(&priv->mutex);
545		iwl_legacy_force_scan_end(priv);
546		mutex_unlock(&priv->mutex);
547	}
548}
549EXPORT_SYMBOL(iwl_legacy_cancel_scan_deferred_work);