xref: /wlan-dirver/qca-wifi-host-cmn/umac/dfs/core/src/misc/dfs_cac.c (revision 8cfe6b10058a04cafb17eed051f2ddf11bee8931)
1 /*
2  * Copyright (c) 2016-2021 The Linux Foundation. All rights reserved.
3  * Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
4  * All rights reserved.
5  * Copyright (c) 2021-2023 Qualcomm Innovation Center, Inc. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /**
29  * DOC: This file has the functions related to DFS CAC.
30  */
31 
32 #include "../dfs_channel.h"
33 #include "../dfs_zero_cac.h"
34 #include <wlan_objmgr_vdev_obj.h>
35 #include "wlan_dfs_utils_api.h"
36 #include "wlan_dfs_mlme_api.h"
37 #include "../dfs_internal.h"
38 #include "../dfs_process_radar_found_ind.h"
39 
40 #define IS_CHANNEL_WEATHER_RADAR(freq) ((freq >= 5600) && (freq <= 5650))
41 #define ADJACENT_WEATHER_RADAR_CHANNEL   5580
42 #define CH100_START_FREQ                 5490
43 #define CH100                            100
44 
45 /*
46  * dfs_cac_valid_timeout() - Timeout function for dfs_cac_valid_timer
47  *                           cac_valid bit will be reset in this function.
48  *
49  * NB: not using kernel-doc format since the kernel-doc script doesn't
50  *     handle the os_timer_func() macro
51  */
52 static os_timer_func(dfs_cac_valid_timeout)
53 {
54 	struct wlan_dfs *dfs = NULL;
55 
56 	OS_GET_TIMER_ARG(dfs, struct wlan_dfs *);
57 	dfs->dfs_cac_valid = 0;
58 	dfs_info(dfs, WLAN_DEBUG_DFS_ALWAYS, ": Timed out!!");
59 }
60 
61 /**
62  * dfs_clear_cac_started_chan() - Clear dfs cac started channel.
63  * @dfs: Pointer to wlan_dfs structure.
64  */
65 void dfs_clear_cac_started_chan(struct wlan_dfs *dfs)
66 {
67 	qdf_mem_zero(&dfs->dfs_cac_started_chan,
68 		     sizeof(dfs->dfs_cac_started_chan));
69 }
70 
71 static void dfs_clear_nol_history_for_curchan(struct wlan_dfs *dfs)
72 {
73 	struct dfs_channel *chan = dfs->dfs_curchan;
74 	uint16_t sub_channels[MAX_20MHZ_SUBCHANS];
75 	uint8_t num_subchs;
76 
77 	num_subchs = dfs_get_bonding_channel_without_seg_info_for_freq(
78 				chan, sub_channels);
79 
80 	if (dfs->dfs_is_stadfs_enabled)
81 		if (dfs_mlme_is_opmode_sta(dfs->dfs_pdev_obj))
82 			utils_dfs_reg_update_nol_history_chan_for_freq(
83 				dfs->dfs_pdev_obj, sub_channels,
84 				num_subchs, DFS_NOL_HISTORY_RESET);
85 }
86 
87 void dfs_process_cac_completion(struct wlan_dfs *dfs)
88 {
89 	enum phy_ch_width ch_width = CH_WIDTH_INVALID;
90 	uint16_t primary_chan_freq = 0, sec_chan_freq = 0;
91 	struct dfs_channel *dfs_curchan;
92 
93 	dfs->dfs_cac_timer_running = 0;
94 	dfs_curchan = dfs->dfs_curchan;
95 
96 	dfs_info(dfs, WLAN_DEBUG_DFS_ALWAYS, "cac expired, chan %d cur time %d",
97 		 dfs->dfs_curchan->dfs_ch_freq,
98 		 (qdf_system_ticks_to_msecs(qdf_system_ticks()) / 1000));
99 
100 	/*
101 	 * When radar is detected during a CAC we are woken up prematurely to
102 	 * switch to a new channel. Check the channel to decide how to act.
103 	 */
104 	if (WLAN_IS_CHAN_RADAR(dfs, dfs->dfs_curchan)) {
105 		dfs_mlme_mark_dfs(dfs->dfs_pdev_obj,
106 				  dfs_curchan->dfs_ch_ieee,
107 				  dfs_curchan->dfs_ch_freq,
108 				  dfs_curchan->dfs_ch_mhz_freq_seg2,
109 				  dfs_curchan->dfs_ch_flags,
110 				  0);
111 		dfs_debug(dfs, WLAN_DEBUG_DFS,
112 			  "CAC timer on chan %u (%u MHz) stopped due to radar",
113 			  dfs_curchan->dfs_ch_ieee,
114 			  dfs_curchan->dfs_ch_freq);
115 	} else {
116 		dfs_debug(dfs, WLAN_DEBUG_DFS,
117 			  "CAC timer on channel %u (%u MHz) expired;"
118 			  "no radar detected",
119 			  dfs_curchan->dfs_ch_ieee,
120 			  dfs_curchan->dfs_ch_freq);
121 
122 		/* On CAC completion, set the bit 'cac_valid'.
123 		 * CAC will not be re-done if this bit is reset.
124 		 * The flag will be reset when dfs_cac_valid_timer
125 		 * timesout.
126 		 */
127 		if (dfs->dfs_cac_valid_time) {
128 			dfs->dfs_cac_valid = 1;
129 			qdf_timer_mod(&dfs->dfs_cac_valid_timer,
130 				      dfs->dfs_cac_valid_time * 1000);
131 		}
132 
133 		dfs_find_curchwidth_and_center_chan_for_freq(dfs,
134 							     &ch_width,
135 							     &primary_chan_freq,
136 							     &sec_chan_freq);
137 
138 		/* ETSI allows the driver to cache the CAC ( Once CAC done,
139 		 * it can be used in future).
140 		 * Therefore mark the current channel CAC done.
141 		 */
142 		if (utils_get_dfsdomain(dfs->dfs_pdev_obj) == DFS_ETSI_DOMAIN)
143 			dfs_mark_precac_done_for_freq(dfs,
144 						      primary_chan_freq,
145 						      sec_chan_freq,
146 						      ch_width);
147 	}
148 
149 	dfs_clear_cac_started_chan(dfs);
150 
151 	/* Clear NOL history for current channel on successful CAC completion */
152 	dfs_clear_nol_history_for_curchan(dfs);
153 	/* Iterate over the nodes, processing the CAC completion event. */
154 	dfs_mlme_proc_cac(dfs->dfs_pdev_obj, 0);
155 
156 	/* Send a CAC timeout, VAP up event to user space */
157 	dfs_mlme_deliver_event_up_after_cac(dfs->dfs_pdev_obj);
158 
159 	if (dfs->dfs_defer_precac_channel_change == 1) {
160 		dfs_mlme_channel_change_by_precac(dfs->dfs_pdev_obj);
161 		dfs->dfs_defer_precac_channel_change = 0;
162 	}
163 }
164 
165 /**
166  * dfs_cac_timeout() - DFS cactimeout function.
167  * @arg: Container of dfs object.
168  *
169  * Sets dfs_cac_timer_running to 0  and dfs_cac_valid_timer.
170  */
171 #ifdef CONFIG_CHAN_FREQ_API
172 static enum qdf_hrtimer_restart_status
173 dfs_cac_timeout(qdf_hrtimer_data_t *arg)
174 {
175 	struct wlan_dfs *dfs;
176 
177 	dfs = container_of(arg, struct wlan_dfs, dfs_cac_timer);
178 
179 	if (dfs_is_hw_mode_switch_in_progress(dfs))
180 		dfs->dfs_defer_params.is_cac_completed = true;
181 	else
182 		dfs_process_cac_completion(dfs);
183 
184 	return QDF_HRTIMER_NORESTART;
185 }
186 #endif
187 
188 #ifdef QCA_SUPPORT_DFS_CAC
189 void dfs_cac_timer_attach(struct wlan_dfs *dfs)
190 {
191 	dfs->dfs_cac_timeout_override = -1;
192 	dfs->wlan_dfs_cac_time = WLAN_DFS_WAIT_MS;
193 	qdf_hrtimer_init(&dfs->dfs_cac_timer,
194 			 dfs_cac_timeout,
195 			 QDF_CLOCK_MONOTONIC,
196 			 QDF_HRTIMER_MODE_REL,
197 			 QDF_CONTEXT_TASKLET);
198 	qdf_timer_init(NULL,
199 			&(dfs->dfs_cac_valid_timer),
200 			dfs_cac_valid_timeout,
201 			(void *)(dfs),
202 			QDF_TIMER_TYPE_WAKE_APPS);
203 }
204 
205 void dfs_cac_timer_reset(struct wlan_dfs *dfs)
206 {
207 	qdf_hrtimer_cancel(&dfs->dfs_cac_timer);
208 	dfs_get_override_cac_timeout(dfs,
209 			&(dfs->dfs_cac_timeout_override));
210 	dfs_clear_cac_started_chan(dfs);
211 }
212 
213 void dfs_cac_timer_detach(struct wlan_dfs *dfs)
214 {
215 	qdf_hrtimer_kill(&dfs->dfs_cac_timer);
216 	qdf_timer_free(&dfs->dfs_cac_valid_timer);
217 	dfs->dfs_cac_valid = 0;
218 }
219 
220 int dfs_is_ap_cac_timer_running(struct wlan_dfs *dfs)
221 {
222 	return dfs->dfs_cac_timer_running;
223 }
224 
225 #ifdef CONFIG_CHAN_FREQ_API
226 void dfs_start_cac_timer(struct wlan_dfs *dfs)
227 {
228 	int cac_timeout = 0;
229 	struct dfs_channel *chan = dfs->dfs_curchan;
230 
231 	cac_timeout =
232 	    dfs_mlme_get_cac_timeout_for_freq(dfs->dfs_pdev_obj,
233 					      chan->dfs_ch_freq,
234 					      chan->dfs_ch_mhz_freq_seg2,
235 					      chan->dfs_ch_flags);
236 
237 	dfs->dfs_cac_started_chan = *chan;
238 
239 	dfs_deliver_cac_state_events(dfs);
240 	dfs_debug(dfs, WLAN_DEBUG_DFS,
241 		  "chan = %d cfreq2 = %d timeout = %d sec, curr_time = %d sec",
242 		  chan->dfs_ch_ieee, chan->dfs_ch_vhtop_ch_freq_seg2,
243 		  cac_timeout,
244 		  qdf_system_ticks_to_msecs(qdf_system_ticks()) / 1000);
245 
246 	qdf_hrtimer_start(&dfs->dfs_cac_timer,
247 			  qdf_time_ms_to_ktime(cac_timeout * 1000),
248 			  QDF_HRTIMER_MODE_REL);
249 	dfs->dfs_cac_aborted = 0;
250 }
251 #endif
252 
253 void dfs_cancel_cac_timer(struct wlan_dfs *dfs)
254 {
255 	qdf_hrtimer_cancel(&dfs->dfs_cac_timer);
256 	dfs_clear_cac_started_chan(dfs);
257 }
258 
259 void dfs_send_dfs_events_for_chan(struct wlan_dfs *dfs,
260 				  struct dfs_channel *chan,
261 				  enum WLAN_DFS_EVENTS event)
262 {
263 	uint8_t nchannels, i;
264 	qdf_freq_t freq_list[MAX_20MHZ_SUBCHANS];
265 
266 	nchannels =
267 		dfs_get_bonding_channel_without_seg_info_for_freq(chan,
268 								  freq_list);
269 	for (i = 0; i < nchannels; i++)
270 		utils_dfs_deliver_event(dfs->dfs_pdev_obj,
271 					freq_list[i],
272 					event);
273 }
274 
275 void dfs_cac_stop(struct wlan_dfs *dfs)
276 {
277 	uint32_t phyerr;
278 	struct dfs_channel *chan;
279 
280 	chan = &dfs->dfs_cac_started_chan;
281 	dfs_get_debug_info(dfs, (void *)&phyerr);
282 	dfs_debug(dfs, WLAN_DEBUG_DFS,
283 		"Stopping CAC Timer %d procphyerr 0x%08x",
284 		 dfs->dfs_curchan->dfs_ch_freq, phyerr);
285 	qdf_hrtimer_cancel(&dfs->dfs_cac_timer);
286 
287 	dfs_send_dfs_events_for_chan(dfs, chan, WLAN_EV_CAC_RESET);
288 
289 	if (dfs->dfs_cac_timer_running)
290 		dfs->dfs_cac_aborted = 1;
291 	dfs_clear_cac_started_chan(dfs);
292 	dfs->dfs_cac_timer_running = 0;
293 }
294 
295 void dfs_stacac_stop(struct wlan_dfs *dfs)
296 {
297 	uint32_t phyerr;
298 
299 	dfs_get_debug_info(dfs, (void *)&phyerr);
300 	dfs_debug(dfs, WLAN_DEBUG_DFS,
301 		"Stopping STA CAC Timer %d procphyerr 0x%08x",
302 		 dfs->dfs_curchan->dfs_ch_freq, phyerr);
303 	dfs_clear_cac_started_chan(dfs);
304 }
305 
306 int dfs_override_cac_timeout(struct wlan_dfs *dfs, int cac_timeout)
307 {
308 	if (!dfs)
309 		return -EIO;
310 
311 	dfs->dfs_cac_timeout_override = cac_timeout;
312 	dfs_info(dfs, WLAN_DEBUG_DFS_ALWAYS, "CAC timeout is now %s %d",
313 		 (cac_timeout == -1) ? "default" : "overridden",
314 		 cac_timeout);
315 
316 	return 0;
317 }
318 
319 int dfs_get_override_cac_timeout(struct wlan_dfs *dfs, int *cac_timeout)
320 {
321 	if (!dfs)
322 		return -EIO;
323 
324 	(*cac_timeout) = dfs->dfs_cac_timeout_override;
325 
326 	return 0;
327 }
328 
329 #ifdef CONFIG_CHAN_FREQ_API
330 void dfs_cac_valid_reset_for_freq(struct wlan_dfs *dfs,
331 				  uint16_t prevchan_freq,
332 				  uint32_t prevchan_flags)
333 {
334 	if (dfs->dfs_cac_valid_time) {
335 		if ((prevchan_freq != dfs->dfs_curchan->dfs_ch_freq) ||
336 		    (prevchan_flags != dfs->dfs_curchan->dfs_ch_flags)) {
337 			dfs_err(dfs, WLAN_DEBUG_DFS_ALWAYS,
338 				"Cancelling timer & clearing cac_valid");
339 			qdf_timer_stop(&dfs->dfs_cac_valid_timer);
340 			dfs->dfs_cac_valid = 0;
341 		}
342 	}
343 }
344 #endif
345 #endif
346 
347 #ifdef CONFIG_CHAN_FREQ_API
348 bool
349 dfs_is_subset_channel_for_freq(uint16_t *old_subchans_freq,
350 			       uint8_t old_n_chans,
351 			       uint16_t *new_subchans_freq,
352 			       uint8_t new_n_chans)
353 {
354 	bool is_found;
355 	int i, j;
356 
357 	if (!new_n_chans)
358 		return true;
359 
360 	if (new_n_chans > old_n_chans)
361 		return false;
362 
363 	for (i = 0; i < new_n_chans; i++) {
364 		is_found = false;
365 		for (j = 0; j < old_n_chans; j++) {
366 			if (new_subchans_freq[i] == old_subchans_freq[j]) {
367 				is_found = true;
368 				break;
369 			}
370 		}
371 
372 		/* If new_subchans[i] is not found in old_subchans, then,
373 		 * new_chan is not subset of old_chan.
374 		 */
375 		if (!is_found)
376 			break;
377 	}
378 
379 	return is_found;
380 }
381 #endif
382 
383 #ifdef CONFIG_CHAN_FREQ_API
384 uint8_t
385 dfs_find_dfs_sub_channels_for_freq(struct wlan_dfs *dfs,
386 				   struct dfs_channel *chan,
387 				   uint16_t *subchan_arr)
388 {
389 	if (WLAN_IS_CHAN_MODE_160(chan) || WLAN_IS_CHAN_MODE_80_80(chan)) {
390 		if (WLAN_IS_CHAN_DFS(chan) && WLAN_IS_CHAN_DFS_CFREQ2(chan))
391 			return dfs_get_bonding_channel_without_seg_info_for_freq
392 				(chan, subchan_arr);
393 		if (WLAN_IS_CHAN_DFS(chan))
394 			return dfs_get_bonding_channels_for_freq(dfs,
395 								 chan,
396 								 SEG_ID_PRIMARY,
397 								 DETECTOR_ID_0,
398 								 subchan_arr);
399 		if (WLAN_IS_CHAN_DFS_CFREQ2(chan))
400 			return dfs_get_bonding_channels_for_freq
401 				(dfs, chan, SEG_ID_SECONDARY,
402 				 DETECTOR_ID_0, subchan_arr);
403 		/* All channels in 160/80_80 BW are non DFS, return 0
404 		 * as number of subchannels
405 		 */
406 		return 0;
407 	} else if (WLAN_IS_CHAN_DFS(chan)) {
408 		return dfs_get_bonding_channel_without_seg_info_for_freq
409 			(chan, subchan_arr);
410 	}
411 	/* All channels are non DFS, return 0 as number of subchannels*/
412 	return 0;
413 }
414 #endif
415 
416 #ifdef CONFIG_CHAN_FREQ_API
417 bool
418 dfs_is_new_chan_subset_of_old_chan(struct wlan_dfs *dfs,
419 				   struct dfs_channel *new_chan,
420 				   struct dfs_channel *old_chan)
421 {
422 	uint16_t new_subchans[MAX_20MHZ_SUBCHANS];
423 	uint16_t old_subchans[MAX_20MHZ_SUBCHANS];
424 	uint8_t n_new_subchans = 0;
425 	uint8_t n_old_subchans = 0;
426 
427 	/* Given channel is the old channel. i.e. The channel which
428 	 * should have the new channel as subset.
429 	 */
430 	n_old_subchans = dfs_find_dfs_sub_channels_for_freq(dfs, old_chan,
431 							    old_subchans);
432 	/* cur_chan is the new channel to be check if subset of old channel */
433 	n_new_subchans = dfs_find_dfs_sub_channels_for_freq(dfs, new_chan,
434 							    new_subchans);
435 
436 	return dfs_is_subset_channel_for_freq(old_subchans,
437 					      n_old_subchans,
438 					      new_subchans,
439 					      n_new_subchans);
440 }
441 #endif
442 
443 #ifdef QCA_SUPPORT_DFS_CAC
444 bool dfs_is_cac_required(struct wlan_dfs *dfs,
445 			 struct dfs_channel *cur_chan,
446 			 struct dfs_channel *prev_chan,
447 			 bool *continue_current_cac,
448 			 bool is_vap_restart)
449 {
450 	struct dfs_channel *cac_started_chan = &dfs->dfs_cac_started_chan;
451 
452 	if (!WLAN_IS_PRIMARY_OR_SECONDARY_CHAN_DFS(cur_chan)) {
453 		dfs_debug(dfs, WLAN_DEBUG_DFS, "Skip CAC on non-DFS channel");
454 		return false;
455 	}
456 
457 	if (dfs->dfs_ignore_dfs || dfs->dfs_cac_valid || dfs->dfs_ignore_cac) {
458 		dfs_debug(dfs, WLAN_DEBUG_DFS,
459 			  "Skip CAC, ignore_dfs = %d cac_valid = %d ignore_cac = %d",
460 			  dfs->dfs_ignore_dfs, dfs->dfs_cac_valid,
461 			  dfs->dfs_ignore_cac);
462 		return false;
463 	}
464 
465 	/* In case of RCAC, check if CAC is completed only on the RCAC channel
466 	 * and do not check the CAC info on current operating channel.
467 	 */
468 	if (dfs_is_agile_rcac_enabled(dfs) &&
469 	    dfs_is_rcac_cac_done(dfs, cur_chan, prev_chan))
470 		return false;
471 
472 	/* If the channel has completed PRE-CAC then CAC can be skipped here. */
473 	if (dfs_is_precac_done(dfs, cur_chan)) {
474 		dfs_debug(dfs, WLAN_DEBUG_DFS,
475 			  "PRE-CAC already done on this channel %d",
476 			  cur_chan->dfs_ch_ieee);
477 		return false;
478 	}
479 
480 	if (dfs_is_ap_cac_timer_running(dfs)) {
481 		/* Check if we should continue the existing CAC or
482 		 * cancel the existing CAC.
483 		 * For example: - if an existing VAP(0) is already in
484 		 * DFS wait state (which means the radio(wifi) is
485 		 * running the CAC) and it is in channel A and another
486 		 * VAP(1) comes up in the same channel then instead of
487 		 * cancelling the CAC we can let the CAC continue.
488 		 */
489 		if (dfs_is_new_chan_subset_of_old_chan(dfs,
490 						       cur_chan,
491 						       cac_started_chan)) {
492 			if (continue_current_cac)
493 				*continue_current_cac = true;
494 		} else {
495 			/* New CAC is needed, cancel the running CAC
496 			 * timer.
497 			 * 1) When AP is in DFS_WAIT state and it is in
498 			 *    channel A and user restarts the AP vap in
499 			 *    channel B, then cancel the running CAC in
500 			 *    channel A and start new CAC in channel B.
501 			 *
502 			 * 2) When AP detects the RADAR during CAC in
503 			 *    channel A, it cancels the running CAC and
504 			 *    tries to find channel B with the reduced
505 			 *    bandwidth with of channel A.
506 			 *    In this case, since the CAC is aborted by
507 			 *    the RADAR, AP should start the CAC again.
508 			 */
509 			dfs_cancel_cac_timer(dfs);
510 		}
511 	} else { /* CAC timer is not running. */
512 		/* If channel change happens via VAP DOWN/UP on subset channels,
513 		 * (eg: from 52 HT80 to 64 HT80) CAC done information
514 		 * (of 52 HT80) based on subset logic
515 		 * (as 52 and 64 HT80 are subsets of each other)
516 		 * is not expected to be preserved as VAP has come up
517 		 * from DOWN state. Hence do not skip CAC on 64 HT80.
518 		 * is_vap_restart flag is used as an identifier to indicate if
519 		 * vap has come up from a DOWN state or UP state (vap restart).
520 		 */
521 		if (!is_vap_restart) {
522 			dfs_debug(dfs, WLAN_DEBUG_DFS, "CAC is needed");
523 			return true;
524 		}
525 		if (dfs_is_new_chan_subset_of_old_chan(dfs,
526 						       cur_chan,
527 						       prev_chan)) {
528 			/* AP bandwidth reduce case:
529 			 * When AP detects the RADAR in in-service monitoring
530 			 * mode in channel A, it cancels the running CAC and
531 			 * tries to find the channel B with the reduced
532 			 * bandwidth of channel A.
533 			 * If the new channel B is subset of the channel A
534 			 * then AP skips the CAC.
535 			 */
536 			if (!dfs->dfs_cac_aborted) {
537 				dfs_debug(dfs, WLAN_DEBUG_DFS, "Skip CAC");
538 				return false;
539 			}
540 		}
541 	}
542 
543 	return true;
544 }
545 #endif
546