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  1/*
  2 * Ultra Wide Band
  3 * Dynamic Reservation Protocol handling
  4 *
  5 * Copyright (C) 2005-2006 Intel Corporation
  6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  7 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
  8 *
  9 * This program is free software; you can redistribute it and/or
 10 * modify it under the terms of the GNU General Public License version
 11 * 2 as published by the Free Software Foundation.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 20 */
 21#include <linux/kthread.h>
 22#include <linux/freezer.h>
 23#include <linux/slab.h>
 24#include <linux/delay.h>
 25#include "uwb-internal.h"
 26
 27
 28/* DRP Conflict Actions ([ECMA-368 2nd Edition] 17.4.6) */
 29enum uwb_drp_conflict_action {
 30	/* Reservation is maintained, no action needed */
 31	UWB_DRP_CONFLICT_MANTAIN = 0,
 32	
 33	/* the device shall not transmit frames in conflicting MASs in
 34	 * the following superframe. If the device is the reservation
 35	 * target, it shall also set the Reason Code in its DRP IE to
 36	 * Conflict in its beacon in the following superframe.
 37	 */
 38	UWB_DRP_CONFLICT_ACT1,
 39	
 40	/* the device shall not set the Reservation Status bit to ONE
 41	 * and shall not transmit frames in conflicting MASs. If the
 42	 * device is the reservation target, it shall also set the
 43	 * Reason Code in its DRP IE to Conflict.
 44	 */	
 45	UWB_DRP_CONFLICT_ACT2,
 46
 47	/* the device shall not transmit frames in conflicting MASs in
 48	 * the following superframe. It shall remove the conflicting
 49	 * MASs from the reservation or set the Reservation Status to
 50	 * ZERO in its beacon in the following superframe. If the
 51	 * device is the reservation target, it shall also set the
 52	 * Reason Code in its DRP IE to Conflict.
 53	 */
 54	UWB_DRP_CONFLICT_ACT3,
 55};
 56
 57
 58static void uwb_rc_set_drp_cmd_done(struct uwb_rc *rc, void *arg,
 59				    struct uwb_rceb *reply, ssize_t reply_size)
 60{
 61	struct uwb_rc_evt_set_drp_ie *r = (struct uwb_rc_evt_set_drp_ie *)reply;
 62
 63	if (r != NULL) {
 64		if (r->bResultCode != UWB_RC_RES_SUCCESS)
 65			dev_err(&rc->uwb_dev.dev, "SET-DRP-IE failed: %s (%d)\n",
 66				uwb_rc_strerror(r->bResultCode), r->bResultCode);
 67	} else
 68		dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: timeout\n");
 69
 70	spin_lock_bh(&rc->rsvs_lock);
 71	if (rc->set_drp_ie_pending > 1) {
 72		rc->set_drp_ie_pending = 0;
 73		uwb_rsv_queue_update(rc);	
 74	} else {
 75		rc->set_drp_ie_pending = 0;	
 76	}
 77	spin_unlock_bh(&rc->rsvs_lock);
 78}
 79
 80/**
 81 * Construct and send the SET DRP IE
 82 *
 83 * @rc:         UWB Host controller
 84 * @returns:    >= 0 number of bytes still available in the beacon
 85 *              < 0 errno code on error.
 86 *
 87 * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the
 88 * device to include in its beacon at the same time. We thus have to
 89 * traverse all reservations and include the DRP IEs of all PENDING
 90 * and NEGOTIATED reservations in a SET DRP command for transmission.
 91 *
 92 * A DRP Availability IE is appended.
 93 *
 94 * rc->rsvs_mutex is held
 95 *
 96 * FIXME We currently ignore the returned value indicating the remaining space
 97 * in beacon. This could be used to deny reservation requests earlier if
 98 * determined that they would cause the beacon space to be exceeded.
 99 */
100int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
101{
102	int result;
103	struct uwb_rc_cmd_set_drp_ie *cmd;
104	struct uwb_rsv *rsv;
105	struct uwb_rsv_move *mv;
106	int num_bytes = 0;
107	u8 *IEDataptr;
108
109	result = -ENOMEM;
110	/* First traverse all reservations to determine memory needed. */
111	list_for_each_entry(rsv, &rc->reservations, rc_node) {
112		if (rsv->drp_ie != NULL) {
113			num_bytes += rsv->drp_ie->hdr.length + 2;
114			if (uwb_rsv_has_two_drp_ies(rsv) &&
115				(rsv->mv.companion_drp_ie != NULL)) {
116				mv = &rsv->mv;
117				num_bytes += mv->companion_drp_ie->hdr.length + 2;	
118			}
119		}
120	}
121	num_bytes += sizeof(rc->drp_avail.ie);
122	cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL);
123	if (cmd == NULL)
124		goto error;
125	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
126	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE);
127	cmd->wIELength = num_bytes;
128	IEDataptr = (u8 *)&cmd->IEData[0];
129
130	/* FIXME: DRV avail IE is not always needed */
131	/* put DRP avail IE first */
132	memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie));
133	IEDataptr += sizeof(struct uwb_ie_drp_avail);
134
135	/* Next traverse all reservations to place IEs in allocated memory. */
136	list_for_each_entry(rsv, &rc->reservations, rc_node) {
137		if (rsv->drp_ie != NULL) {
138			memcpy(IEDataptr, rsv->drp_ie,
139			       rsv->drp_ie->hdr.length + 2);
140			IEDataptr += rsv->drp_ie->hdr.length + 2;
141			
142			if (uwb_rsv_has_two_drp_ies(rsv) &&
143				(rsv->mv.companion_drp_ie != NULL)) {
144				mv = &rsv->mv;
145				memcpy(IEDataptr, mv->companion_drp_ie,
146				       mv->companion_drp_ie->hdr.length + 2);
147				IEDataptr += mv->companion_drp_ie->hdr.length + 2;	
148			}
149		}
150	}
151
152	result = uwb_rc_cmd_async(rc, "SET-DRP-IE", &cmd->rccb, sizeof(*cmd) + num_bytes,
153				  UWB_RC_CET_GENERAL, UWB_RC_CMD_SET_DRP_IE,
154				  uwb_rc_set_drp_cmd_done, NULL);
155	
156	rc->set_drp_ie_pending = 1;
157
158	kfree(cmd);
159error:
160	return result;
161}
162
163/*
164 * Evaluate the action to perform using conflict resolution rules
165 *
166 * Return a uwb_drp_conflict_action.
167 */
168static int evaluate_conflict_action(struct uwb_ie_drp *ext_drp_ie, int ext_beacon_slot,
169				    struct uwb_rsv *rsv, int our_status)
170{
171	int our_tie_breaker = rsv->tiebreaker;
172	int our_type        = rsv->type;
173	int our_beacon_slot = rsv->rc->uwb_dev.beacon_slot;
174
175	int ext_tie_breaker = uwb_ie_drp_tiebreaker(ext_drp_ie);
176	int ext_status      = uwb_ie_drp_status(ext_drp_ie);
177	int ext_type        = uwb_ie_drp_type(ext_drp_ie);
178	
179	
180	/* [ECMA-368 2nd Edition] 17.4.6 */
181	if (ext_type == UWB_DRP_TYPE_PCA && our_type == UWB_DRP_TYPE_PCA) {
182		return UWB_DRP_CONFLICT_MANTAIN;
183	}
184
185	/* [ECMA-368 2nd Edition] 17.4.6-1 */
186	if (our_type == UWB_DRP_TYPE_ALIEN_BP) {
187		return UWB_DRP_CONFLICT_MANTAIN;
188	}
189	
190	/* [ECMA-368 2nd Edition] 17.4.6-2 */
191	if (ext_type == UWB_DRP_TYPE_ALIEN_BP) {
192		/* here we know our_type != UWB_DRP_TYPE_ALIEN_BP */
193		return UWB_DRP_CONFLICT_ACT1;
194	}
195
196	/* [ECMA-368 2nd Edition] 17.4.6-3 */
197	if (our_status == 0 && ext_status == 1) {
198		return UWB_DRP_CONFLICT_ACT2;
199	}
200
201	/* [ECMA-368 2nd Edition] 17.4.6-4 */
202	if (our_status == 1 && ext_status == 0) {
203		return UWB_DRP_CONFLICT_MANTAIN;
204	}
205
206	/* [ECMA-368 2nd Edition] 17.4.6-5a */
207	if (our_tie_breaker == ext_tie_breaker &&
208	    our_beacon_slot <  ext_beacon_slot) {
209		return UWB_DRP_CONFLICT_MANTAIN;
210	}
211
212	/* [ECMA-368 2nd Edition] 17.4.6-5b */
213	if (our_tie_breaker != ext_tie_breaker &&
214	    our_beacon_slot >  ext_beacon_slot) {
215		return UWB_DRP_CONFLICT_MANTAIN;
216	}
217	
218	if (our_status == 0) {
219		if (our_tie_breaker == ext_tie_breaker) {
220			/* [ECMA-368 2nd Edition] 17.4.6-6a */
221			if (our_beacon_slot > ext_beacon_slot) {
222				return UWB_DRP_CONFLICT_ACT2;
223			}
224		} else  {
225			/* [ECMA-368 2nd Edition] 17.4.6-6b */
226			if (our_beacon_slot < ext_beacon_slot) {
227				return UWB_DRP_CONFLICT_ACT2;
228			}
229		}
230	} else {
231		if (our_tie_breaker == ext_tie_breaker) {
232			/* [ECMA-368 2nd Edition] 17.4.6-7a */
233			if (our_beacon_slot > ext_beacon_slot) {
234				return UWB_DRP_CONFLICT_ACT3;
235			}
236		} else {
237			/* [ECMA-368 2nd Edition] 17.4.6-7b */
238			if (our_beacon_slot < ext_beacon_slot) {
239				return UWB_DRP_CONFLICT_ACT3;
240			}
241		}
242	}
243	return UWB_DRP_CONFLICT_MANTAIN;
244}
245
246static void handle_conflict_normal(struct uwb_ie_drp *drp_ie, 
247				   int ext_beacon_slot, 
248				   struct uwb_rsv *rsv, 
249				   struct uwb_mas_bm *conflicting_mas)
250{
251	struct uwb_rc *rc = rsv->rc;
252	struct uwb_rsv_move *mv = &rsv->mv;
253	struct uwb_drp_backoff_win *bow = &rc->bow;
254	int action;
255
256	action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, uwb_rsv_status(rsv));
257
258	if (uwb_rsv_is_owner(rsv)) {
259		switch(action) {
260		case UWB_DRP_CONFLICT_ACT2:
261			/* try move */
262			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_TO_BE_MOVED);
263			if (bow->can_reserve_extra_mases == false)
264				uwb_rsv_backoff_win_increment(rc);
265			
266			break;
267		case UWB_DRP_CONFLICT_ACT3:
268			uwb_rsv_backoff_win_increment(rc);
269			/* drop some mases with reason modified */
270			/* put in the companion the mases to be dropped */
271			bitmap_and(mv->companion_mas.bm, rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS);
272			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
273		default:
274			break;
275		}
276	} else {
277		switch(action) {
278		case UWB_DRP_CONFLICT_ACT2:
279		case UWB_DRP_CONFLICT_ACT3:
280			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);	
281		default:
282			break;
283		}
284
285	}
286	
287}
288
289static void handle_conflict_expanding(struct uwb_ie_drp *drp_ie, int ext_beacon_slot,
290				      struct uwb_rsv *rsv, bool companion_only,
291				      struct uwb_mas_bm *conflicting_mas)
292{
293	struct uwb_rc *rc = rsv->rc;
294	struct uwb_drp_backoff_win *bow = &rc->bow;
295	struct uwb_rsv_move *mv = &rsv->mv;
296	int action;
297	
298	if (companion_only) {
299		/* status of companion is 0 at this point */
300		action = evaluate_conflict_action(drp_ie, ext_beacon_slot, rsv, 0);
301		if (uwb_rsv_is_owner(rsv)) {
302			switch(action) {
303			case UWB_DRP_CONFLICT_ACT2:
304			case UWB_DRP_CONFLICT_ACT3:
305				uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
306				rsv->needs_release_companion_mas = false;
307				if (bow->can_reserve_extra_mases == false)
308					uwb_rsv_backoff_win_increment(rc);
309				uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
310			}
311		} else { /* rsv is target */			
312			switch(action) {
313			case UWB_DRP_CONFLICT_ACT2:
314			case UWB_DRP_CONFLICT_ACT3:
315				uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_EXPANDING_CONFLICT);
316                                /* send_drp_avail_ie = true; */
317			}
318		}
319	} else { /* also base part of the reservation is conflicting */		
320		if (uwb_rsv_is_owner(rsv)) {
321			uwb_rsv_backoff_win_increment(rc);
322			/* remove companion part */
323			uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
324
325			/* drop some mases with reason modified */
326
327			/* put in the companion the mases to be dropped */
328			bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS);
329			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);
330		} else { /* it is a target rsv */
331			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
332                        /* send_drp_avail_ie = true; */
333		}
334	}
335}
336
337static void uwb_drp_handle_conflict_rsv(struct uwb_rc *rc, struct uwb_rsv *rsv,
338					struct uwb_rc_evt_drp *drp_evt, 
339					struct uwb_ie_drp *drp_ie,
340					struct uwb_mas_bm *conflicting_mas)
341{
342	struct uwb_rsv_move *mv;
343
344	/* check if the conflicting reservation has two drp_ies */
345	if (uwb_rsv_has_two_drp_ies(rsv)) {
346		mv = &rsv->mv;
347		if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS)) {
348			handle_conflict_expanding(drp_ie, drp_evt->beacon_slot_number,
349						  rsv, false, conflicting_mas);
350		} else {
351			if (bitmap_intersects(mv->companion_mas.bm, conflicting_mas->bm, UWB_NUM_MAS)) {
352				handle_conflict_expanding(drp_ie, drp_evt->beacon_slot_number,
353							  rsv, true, conflicting_mas);	
354			}
355		}
356	} else if (bitmap_intersects(rsv->mas.bm, conflicting_mas->bm, UWB_NUM_MAS)) {
357		handle_conflict_normal(drp_ie, drp_evt->beacon_slot_number, rsv, conflicting_mas);
358	}
359}
360
361static void uwb_drp_handle_all_conflict_rsv(struct uwb_rc *rc,
362					    struct uwb_rc_evt_drp *drp_evt, 
363					    struct uwb_ie_drp *drp_ie,
364					    struct uwb_mas_bm *conflicting_mas)
365{
366	struct uwb_rsv *rsv;
367	
368	list_for_each_entry(rsv, &rc->reservations, rc_node) {
369		uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie, conflicting_mas);	
370	}
371}
372	
373/*
374 * Based on the DRP IE, transition a target reservation to a new
375 * state.
376 */
377static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv,
378				   struct uwb_ie_drp *drp_ie, struct uwb_rc_evt_drp *drp_evt)
379{
380	struct device *dev = &rc->uwb_dev.dev;
381	struct uwb_rsv_move *mv = &rsv->mv;
382	int status;
383	enum uwb_drp_reason reason_code;
384	struct uwb_mas_bm mas;
385	
386	status = uwb_ie_drp_status(drp_ie);
387	reason_code = uwb_ie_drp_reason_code(drp_ie);
388	uwb_drp_ie_to_bm(&mas, drp_ie);
389
390	switch (reason_code) {
391	case UWB_DRP_REASON_ACCEPTED:
392
393		if (rsv->state == UWB_RSV_STATE_T_CONFLICT) {
394			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_CONFLICT);
395			break;
396		}
397
398		if (rsv->state == UWB_RSV_STATE_T_EXPANDING_ACCEPTED) {
399			/* drp_ie is companion */
400			if (!bitmap_equal(rsv->mas.bm, mas.bm, UWB_NUM_MAS))
401				/* stroke companion */
402				uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);	
403		} else {
404			if (!bitmap_equal(rsv->mas.bm, mas.bm, UWB_NUM_MAS)) {
405				if (uwb_drp_avail_reserve_pending(rc, &mas) == -EBUSY) {
406					/* FIXME: there is a conflict, find
407					 * the conflicting reservations and
408					 * take a sensible action. Consider
409					 * that in drp_ie there is the
410					 * "neighbour" */
411					uwb_drp_handle_all_conflict_rsv(rc, drp_evt, drp_ie, &mas);
412				} else {
413					/* accept the extra reservation */
414					bitmap_copy(mv->companion_mas.bm, mas.bm, UWB_NUM_MAS);
415					uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
416				}
417			} else {
418				if (status) {
419					uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
420				}
421			}
422			
423		}
424		break;
425
426	case UWB_DRP_REASON_MODIFIED:
427		/* check to see if we have already modified the reservation */
428		if (bitmap_equal(rsv->mas.bm, mas.bm, UWB_NUM_MAS)) {
429			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
430			break;
431		}
432
433		/* find if the owner wants to expand or reduce */
434		if (bitmap_subset(mas.bm, rsv->mas.bm, UWB_NUM_MAS)) {
435			/* owner is reducing */
436			bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mas.bm, UWB_NUM_MAS);
437			uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
438		}
439
440		bitmap_copy(rsv->mas.bm, mas.bm, UWB_NUM_MAS);
441		uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_RESIZED);
442		break;
443	default:
444		dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
445			 reason_code, status);
446	}
447}
448
449/*
450 * Based on the DRP IE, transition an owner reservation to a new
451 * state.
452 */
453static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv,
454				  struct uwb_dev *src, struct uwb_ie_drp *drp_ie,
455				  struct uwb_rc_evt_drp *drp_evt)
456{
457	struct device *dev = &rc->uwb_dev.dev;
458	struct uwb_rsv_move *mv = &rsv->mv;
459	int status;
460	enum uwb_drp_reason reason_code;
461	struct uwb_mas_bm mas;
462
463	status = uwb_ie_drp_status(drp_ie);
464	reason_code = uwb_ie_drp_reason_code(drp_ie);
465	uwb_drp_ie_to_bm(&mas, drp_ie);
466
467	if (status) {
468		switch (reason_code) {
469		case UWB_DRP_REASON_ACCEPTED:
470			switch (rsv->state) {
471			case UWB_RSV_STATE_O_PENDING:
472			case UWB_RSV_STATE_O_INITIATED:
473			case UWB_RSV_STATE_O_ESTABLISHED:
474				uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
475				break;
476			case UWB_RSV_STATE_O_MODIFIED:
477				if (bitmap_equal(mas.bm, rsv->mas.bm, UWB_NUM_MAS)) {
478					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
479				} else {
480					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MODIFIED);	
481				}
482				break;
483				
484			case UWB_RSV_STATE_O_MOVE_REDUCING: /* shouldn' t be a problem */
485				if (bitmap_equal(mas.bm, rsv->mas.bm, UWB_NUM_MAS)) {
486					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
487				} else {
488					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);	
489				}
490				break;
491			case UWB_RSV_STATE_O_MOVE_EXPANDING:
492				if (bitmap_equal(mas.bm, mv->companion_mas.bm, UWB_NUM_MAS)) {
493					/* Companion reservation accepted */
494					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
495				} else {
496					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
497				}
498				break;
499			case UWB_RSV_STATE_O_MOVE_COMBINING:
500				if (bitmap_equal(mas.bm, rsv->mas.bm, UWB_NUM_MAS))
501					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
502				else
503					uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
504				break;
505			default:
506				break;	
507			}
508			break;
509		default:
510			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
511				 reason_code, status);
512		}
513	} else {
514		switch (reason_code) {
515		case UWB_DRP_REASON_PENDING:
516			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING);
517			break;
518		case UWB_DRP_REASON_DENIED:
519			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
520			break;
521		case UWB_DRP_REASON_CONFLICT:
522			/* resolve the conflict */
523			bitmap_complement(mas.bm, src->last_availability_bm,
524					  UWB_NUM_MAS);
525			uwb_drp_handle_conflict_rsv(rc, rsv, drp_evt, drp_ie, &mas);
526			break;
527		default:
528			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
529				 reason_code, status);
530		}
531	}
532}
533
534static void uwb_cnflt_alien_stroke_timer(struct uwb_cnflt_alien *cnflt)
535{
536	unsigned timeout_us = UWB_MAX_LOST_BEACONS * UWB_SUPERFRAME_LENGTH_US;
537	mod_timer(&cnflt->timer, jiffies + usecs_to_jiffies(timeout_us));
538}
539
540static void uwb_cnflt_update_work(struct work_struct *work)
541{
542	struct uwb_cnflt_alien *cnflt = container_of(work,
543						     struct uwb_cnflt_alien,
544						     cnflt_update_work);
545	struct uwb_cnflt_alien *c;
546	struct uwb_rc *rc = cnflt->rc;
547	
548	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
549	
550	mutex_lock(&rc->rsvs_mutex);
551
552	list_del(&cnflt->rc_node);
553
554	/* update rc global conflicting alien bitmap */
555	bitmap_zero(rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
556
557	list_for_each_entry(c, &rc->cnflt_alien_list, rc_node) {
558		bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm, c->mas.bm, UWB_NUM_MAS);			
559	}
560	
561	queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work, usecs_to_jiffies(delay_us));
562
563	kfree(cnflt);
564	mutex_unlock(&rc->rsvs_mutex);
565}
566
567static void uwb_cnflt_timer(unsigned long arg)
568{
569	struct uwb_cnflt_alien *cnflt = (struct uwb_cnflt_alien *)arg;
570
571	queue_work(cnflt->rc->rsv_workq, &cnflt->cnflt_update_work);
572}
573
574/*
575 * We have received an DRP_IE of type Alien BP and we need to make
576 * sure we do not transmit in conflicting MASs.
577 */
578static void uwb_drp_handle_alien_drp(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
579{
580	struct device *dev = &rc->uwb_dev.dev;
581	struct uwb_mas_bm mas;
582	struct uwb_cnflt_alien *cnflt;
583	char buf[72];
584	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;
585	
586	uwb_drp_ie_to_bm(&mas, drp_ie);
587	bitmap_scnprintf(buf, sizeof(buf), mas.bm, UWB_NUM_MAS);
588	
589	list_for_each_entry(cnflt, &rc->cnflt_alien_list, rc_node) {
590		if (bitmap_equal(cnflt->mas.bm, mas.bm, UWB_NUM_MAS)) {
591			/* Existing alien BP reservation conflicting
592			 * bitmap, just reset the timer */
593			uwb_cnflt_alien_stroke_timer(cnflt);
594			return;
595		}
596	}
597
598	/* New alien BP reservation conflicting bitmap */
599
600	/* alloc and initialize new uwb_cnflt_alien */
601	cnflt = kzalloc(sizeof(struct uwb_cnflt_alien), GFP_KERNEL);
602	if (!cnflt)
603		dev_err(dev, "failed to alloc uwb_cnflt_alien struct\n");
604	INIT_LIST_HEAD(&cnflt->rc_node);
605	init_timer(&cnflt->timer);
606	cnflt->timer.function = uwb_cnflt_timer;
607	cnflt->timer.data     = (unsigned long)cnflt;
608
609	cnflt->rc = rc;
610	INIT_WORK(&cnflt->cnflt_update_work, uwb_cnflt_update_work);
611	
612	bitmap_copy(cnflt->mas.bm, mas.bm, UWB_NUM_MAS);
613
614	list_add_tail(&cnflt->rc_node, &rc->cnflt_alien_list);
615
616	/* update rc global conflicting alien bitmap */
617	bitmap_or(rc->cnflt_alien_bitmap.bm, rc->cnflt_alien_bitmap.bm, mas.bm, UWB_NUM_MAS);
618
619	queue_delayed_work(rc->rsv_workq, &rc->rsv_alien_bp_work, usecs_to_jiffies(delay_us));
620	
621	/* start the timer */
622	uwb_cnflt_alien_stroke_timer(cnflt);
623}
624
625static void uwb_drp_process_not_involved(struct uwb_rc *rc,
626					 struct uwb_rc_evt_drp *drp_evt, 
627					 struct uwb_ie_drp *drp_ie)
628{
629	struct uwb_mas_bm mas;
630	
631	uwb_drp_ie_to_bm(&mas, drp_ie);
632	uwb_drp_handle_all_conflict_rsv(rc, drp_evt, drp_ie, &mas);
633}
634
635static void uwb_drp_process_involved(struct uwb_rc *rc, struct uwb_dev *src,
636				     struct uwb_rc_evt_drp *drp_evt,
637				     struct uwb_ie_drp *drp_ie)
638{
639	struct uwb_rsv *rsv;
640
641	rsv = uwb_rsv_find(rc, src, drp_ie);
642	if (!rsv) {
643		/*
644		 * No reservation? It's either for a recently
645		 * terminated reservation; or the DRP IE couldn't be
646		 * processed (e.g., an invalid IE or out of memory).
647		 */
648		return;
649	}
650	
651	/*
652	 * Do nothing with DRP IEs for reservations that have been
653	 * terminated.
654	 */
655	if (rsv->state == UWB_RSV_STATE_NONE) {
656		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
657		return;
658	}
659			
660	if (uwb_ie_drp_owner(drp_ie))
661		uwb_drp_process_target(rc, rsv, drp_ie, drp_evt);
662	else
663		uwb_drp_process_owner(rc, rsv, src, drp_ie, drp_evt);
664	
665}
666
667
668static bool uwb_drp_involves_us(struct uwb_rc *rc, struct uwb_ie_drp *drp_ie)
669{
670	return uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, &drp_ie->dev_addr) == 0;
671}
672
673/*
674 * Process a received DRP IE.
675 */
676static void uwb_drp_process(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
677			    struct uwb_dev *src, struct uwb_ie_drp *drp_ie)
678{
679	if (uwb_ie_drp_type(drp_ie) == UWB_DRP_TYPE_ALIEN_BP)
680		uwb_drp_handle_alien_drp(rc, drp_ie);
681	else if (uwb_drp_involves_us(rc, drp_ie))
682		uwb_drp_process_involved(rc, src, drp_evt, drp_ie);
683	else
684		uwb_drp_process_not_involved(rc, drp_evt, drp_ie);
685}
686
687/*
688 * Process a received DRP Availability IE
689 */
690static void uwb_drp_availability_process(struct uwb_rc *rc, struct uwb_dev *src,
691					 struct uwb_ie_drp_avail *drp_availability_ie)
692{
693	bitmap_copy(src->last_availability_bm,
694		    drp_availability_ie->bmp, UWB_NUM_MAS);
695}
696
697/*
698 * Process all the DRP IEs (both DRP IEs and the DRP Availability IE)
699 * from a device.
700 */
701static
702void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
703			 size_t ielen, struct uwb_dev *src_dev)
704{
705	struct device *dev = &rc->uwb_dev.dev;
706	struct uwb_ie_hdr *ie_hdr;
707	void *ptr;
708
709	ptr = drp_evt->ie_data;
710	for (;;) {
711		ie_hdr = uwb_ie_next(&ptr, &ielen);
712		if (!ie_hdr)
713			break;
714
715		switch (ie_hdr->element_id) {
716		case UWB_IE_DRP_AVAILABILITY:
717			uwb_drp_availability_process(rc, src_dev, (struct uwb_ie_drp_avail *)ie_hdr);
718			break;
719		case UWB_IE_DRP:
720			uwb_drp_process(rc, drp_evt, src_dev, (struct uwb_ie_drp *)ie_hdr);
721			break;
722		default:
723			dev_warn(dev, "unexpected IE in DRP notification\n");
724			break;
725		}
726	}
727
728	if (ielen > 0)
729		dev_warn(dev, "%d octets remaining in DRP notification\n",
730			 (int)ielen);
731}
732
733/**
734 * uwbd_evt_handle_rc_drp - handle a DRP_IE event
735 * @evt: the DRP_IE event from the radio controller
736 *
737 * This processes DRP notifications from the radio controller, either
738 * initiating a new reservation or transitioning an existing
739 * reservation into a different state.
740 *
741 * DRP notifications can occur for three different reasons:
742 *
743 * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as
744 *   the target or source have been received.
745 *
746 *   These DRP IEs could be new or for an existing reservation.
747 *
748 *   If the DRP IE for an existing reservation ceases to be to
749 *   received for at least mMaxLostBeacons, the reservation should be
750 *   considered to be terminated.  Note that the TERMINATE reason (see
751 *   below) may not always be signalled (e.g., the remote device has
752 *   two or more reservations established with the RC).
753 *
754 * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon
755 *   group conflict with the RC's reservations.
756 *
757 * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received
758 *   from a device (i.e., it's terminated all reservations).
759 *
760 * Only the software state of the reservations is changed; the setting
761 * of the radio controller's DRP IEs is done after all the events in
762 * an event buffer are processed.  This saves waiting multiple times
763 * for the SET_DRP_IE command to complete.
764 */
765int uwbd_evt_handle_rc_drp(struct uwb_event *evt)
766{
767	struct device *dev = &evt->rc->uwb_dev.dev;
768	struct uwb_rc *rc = evt->rc;
769	struct uwb_rc_evt_drp *drp_evt;
770	size_t ielength, bytes_left;
771	struct uwb_dev_addr src_addr;
772	struct uwb_dev *src_dev;
773
774	/* Is there enough data to decode the event (and any IEs in
775	   its payload)? */
776	if (evt->notif.size < sizeof(*drp_evt)) {
777		dev_err(dev, "DRP event: Not enough data to decode event "
778			"[%zu bytes left, %zu needed]\n",
779			evt->notif.size, sizeof(*drp_evt));
780		return 0;
781	}
782	bytes_left = evt->notif.size - sizeof(*drp_evt);
783	drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb);
784	ielength = le16_to_cpu(drp_evt->ie_length);
785	if (bytes_left != ielength) {
786		dev_err(dev, "DRP event: Not enough data in payload [%zu"
787			"bytes left, %zu declared in the event]\n",
788			bytes_left, ielength);
789		return 0;
790	}
791
792	memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr));
793	src_dev = uwb_dev_get_by_devaddr(rc, &src_addr);
794	if (!src_dev) {
795		/*
796		 * A DRP notification from an unrecognized device.
797		 *
798		 * This is probably from a WUSB device that doesn't
799		 * have an EUI-48 and therefore doesn't show up in the
800		 * UWB device database.  It's safe to simply ignore
801		 * these.
802		 */
803		return 0;
804	}
805
806	mutex_lock(&rc->rsvs_mutex);
807
808	/* We do not distinguish from the reason */
809	uwb_drp_process_all(rc, drp_evt, ielength, src_dev);
810
811	mutex_unlock(&rc->rsvs_mutex);
812
813	uwb_dev_put(src_dev);
814	return 0;
815}