aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/uwb/drp.c
blob: fe328146adb7844f3ab0ba5efd5e7505d9b2b965 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
/*
 * Ultra Wide Band
 * Dynamic Reservation Protocol handling
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 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, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/delay.h>
#include "uwb-internal.h"

/**
 * Construct and send the SET DRP IE
 *
 * @rc:         UWB Host controller
 * @returns:    >= 0 number of bytes still available in the beacon
 *              < 0 errno code on error.
 *
 * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the
 * device to include in its beacon at the same time. We thus have to
 * traverse all reservations and include the DRP IEs of all PENDING
 * and NEGOTIATED reservations in a SET DRP command for transmission.
 *
 * A DRP Availability IE is appended.
 *
 * rc->rsvs_mutex is held
 *
 * FIXME We currently ignore the returned value indicating the remaining space
 * in beacon. This could be used to deny reservation requests earlier if
 * determined that they would cause the beacon space to be exceeded.
 */
int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
{
	int result;
	struct device *dev = &rc->uwb_dev.dev;
	struct uwb_rc_cmd_set_drp_ie *cmd;
	struct uwb_rc_evt_set_drp_ie reply;
	struct uwb_rsv *rsv;
	int num_bytes = 0;
	u8 *IEDataptr;

	result = -ENOMEM;
	/* First traverse all reservations to determine memory needed. */
	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (rsv->drp_ie != NULL)
			num_bytes += rsv->drp_ie->hdr.length + 2;
	}
	num_bytes += sizeof(rc->drp_avail.ie);
	cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL);
	if (cmd == NULL)
		goto error;
	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE);
	cmd->wIELength = num_bytes;
	IEDataptr = (u8 *)&cmd->IEData[0];

	/* Next traverse all reservations to place IEs in allocated memory. */
	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (rsv->drp_ie != NULL) {
			memcpy(IEDataptr, rsv->drp_ie,
			       rsv->drp_ie->hdr.length + 2);
			IEDataptr += rsv->drp_ie->hdr.length + 2;
		}
	}
	memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie));

	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
	reply.rceb.wEvent = UWB_RC_CMD_SET_DRP_IE;
	result = uwb_rc_cmd(rc, "SET-DRP-IE", &cmd->rccb,
			sizeof(*cmd) + num_bytes, &reply.rceb,
			sizeof(reply));
	if (result < 0)
		goto error_cmd;
	result = le16_to_cpu(reply.wRemainingSpace);
	if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
		dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: command execution "
				"failed: %s (%d). RemainingSpace in beacon "
				"= %d\n", uwb_rc_strerror(reply.bResultCode),
				reply.bResultCode, result);
		result = -EIO;
	} else {
		dev_dbg(dev, "SET-DRP-IE sent. RemainingSpace in beacon "
			     "= %d.\n", result);
		result = 0;
	}
error_cmd:
	kfree(cmd);
error:
	return result;
}

void uwb_drp_handle_timeout(struct uwb_rsv *rsv)
{
	struct device *dev = &rsv->rc->uwb_dev.dev;

	dev_dbg(dev, "reservation timeout in state %s (%d)\n",
		uwb_rsv_state_str(rsv->state), rsv->state);

	switch (rsv->state) {
	case UWB_RSV_STATE_O_INITIATED:
		if (rsv->is_multicast) {
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
			return;
		}
		break;
	case UWB_RSV_STATE_O_ESTABLISHED:
		if (rsv->is_multicast)
			return;
		break;
	default:
		break;
	}
	uwb_rsv_remove(rsv);
}

/*
 * Based on the DRP IE, transition a target reservation to a new
 * state.
 */
static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv,
				   struct uwb_ie_drp *drp_ie)
{
	struct device *dev = &rc->uwb_dev.dev;
	int status;
	enum uwb_drp_reason reason_code;

	status = uwb_ie_drp_status(drp_ie);
	reason_code = uwb_ie_drp_reason_code(drp_ie);

	if (status) {
		switch (reason_code) {
		case UWB_DRP_REASON_ACCEPTED:
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
			break;
		case UWB_DRP_REASON_MODIFIED:
			dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n",
				reason_code, status);
			break;
		default:
			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
				 reason_code, status);
		}
	} else {
		switch (reason_code) {
		case UWB_DRP_REASON_ACCEPTED:
			/* New reservations are handled in uwb_rsv_find(). */
			break;
		case UWB_DRP_REASON_DENIED:
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
			break;
		case UWB_DRP_REASON_CONFLICT:
		case UWB_DRP_REASON_MODIFIED:
			dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n",
				reason_code, status);
			break;
		default:
			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
				 reason_code, status);
		}
	}
}

/*
 * Based on the DRP IE, transition an owner reservation to a new
 * state.
 */
static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv,
				  struct uwb_ie_drp *drp_ie)
{
	struct device *dev = &rc->uwb_dev.dev;
	int status;
	enum uwb_drp_reason reason_code;

	status = uwb_ie_drp_status(drp_ie);
	reason_code = uwb_ie_drp_reason_code(drp_ie);

	if (status) {
		switch (reason_code) {
		case UWB_DRP_REASON_ACCEPTED:
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
			break;
		case UWB_DRP_REASON_MODIFIED:
			dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n",
				reason_code, status);
			break;
		default:
			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
				 reason_code, status);
		}
	} else {
		switch (reason_code) {
		case UWB_DRP_REASON_PENDING:
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING);
			break;
		case UWB_DRP_REASON_DENIED:
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
			break;
		case UWB_DRP_REASON_CONFLICT:
		case UWB_DRP_REASON_MODIFIED:
			dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n",
				reason_code, status);
			break;
		default:
			dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n",
				 reason_code, status);
		}
	}
}

/*
 * Process a received DRP IE, it's either for a reservation owned by
 * the RC or targeted at it (or it's for a WUSB cluster reservation).
 */
static void uwb_drp_process(struct uwb_rc *rc, struct uwb_dev *src,
		     struct uwb_ie_drp *drp_ie)
{
	struct uwb_rsv *rsv;

	rsv = uwb_rsv_find(rc, src, drp_ie);
	if (!rsv) {
		/*
		 * No reservation? It's either for a recently
		 * terminated reservation; or the DRP IE couldn't be
		 * processed (e.g., an invalid IE or out of memory).
		 */
		return;
	}

	/*
	 * Do nothing with DRP IEs for reservations that have been
	 * terminated.
	 */
	if (rsv->state == UWB_RSV_STATE_NONE) {
		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
		return;
	}

	if (uwb_ie_drp_owner(drp_ie))
		uwb_drp_process_target(rc, rsv, drp_ie);
	else
		uwb_drp_process_owner(rc, rsv, drp_ie);
}


/*
 * Process all the DRP IEs (both DRP IEs and the DRP Availability IE)
 * from a device.
 */
static
void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
			 size_t ielen, struct uwb_dev *src_dev)
{
	struct device *dev = &rc->uwb_dev.dev;
	struct uwb_ie_hdr *ie_hdr;
	void *ptr;

	ptr = drp_evt->ie_data;
	for (;;) {
		ie_hdr = uwb_ie_next(&ptr, &ielen);
		if (!ie_hdr)
			break;

		switch (ie_hdr->element_id) {
		case UWB_IE_DRP_AVAILABILITY:
			/* FIXME: does something need to be done with this? */
			break;
		case UWB_IE_DRP:
			uwb_drp_process(rc, src_dev, (struct uwb_ie_drp *)ie_hdr);
			break;
		default:
			dev_warn(dev, "unexpected IE in DRP notification\n");
			break;
		}
	}

	if (ielen > 0)
		dev_warn(dev, "%d octets remaining in DRP notification\n",
			 (int)ielen);
}


/*
 * Go through all the DRP IEs and find the ones that conflict with our
 * reservations.
 *
 * FIXME: must resolve the conflict according the the rules in
 * [ECMA-368].
 */
static
void uwb_drp_process_conflict_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt,
				  size_t ielen, struct uwb_dev *src_dev)
{
	struct device *dev = &rc->uwb_dev.dev;
	struct uwb_ie_hdr *ie_hdr;
	struct uwb_ie_drp *drp_ie;
	void *ptr;

	ptr = drp_evt->ie_data;
	for (;;) {
		ie_hdr = uwb_ie_next(&ptr, &ielen);
		if (!ie_hdr)
			break;

		drp_ie = container_of(ie_hdr, struct uwb_ie_drp, hdr);

		/* FIXME: check if this DRP IE conflicts. */
	}

	if (ielen > 0)
		dev_warn(dev, "%d octets remaining in DRP notification\n",
			 (int)ielen);
}


/*
 * Terminate all reservations owned by, or targeted at, 'uwb_dev'.
 */
static void uwb_drp_terminate_all(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
{
	struct uwb_rsv *rsv;

	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (rsv->owner == uwb_dev
		    || (rsv->target.type == UWB_RSV_TARGET_DEV && rsv->target.dev == uwb_dev))
			uwb_rsv_remove(rsv);
	}
}


/**
 * uwbd_evt_handle_rc_drp - handle a DRP_IE event
 * @evt: the DRP_IE event from the radio controller
 *
 * This processes DRP notifications from the radio controller, either
 * initiating a new reservation or transitioning an existing
 * reservation into a different state.
 *
 * DRP notifications can occur for three different reasons:
 *
 * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as
 *   the target or source have been recieved.
 *
 *   These DRP IEs could be new or for an existing reservation.
 *
 *   If the DRP IE for an existing reservation ceases to be to
 *   recieved for at least mMaxLostBeacons, the reservation should be
 *   considered to be terminated.  Note that the TERMINATE reason (see
 *   below) may not always be signalled (e.g., the remote device has
 *   two or more reservations established with the RC).
 *
 * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon
 *   group conflict with the RC's reservations.
 *
 * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received
 *   from a device (i.e., it's terminated all reservations).
 *
 * Only the software state of the reservations is changed; the setting
 * of the radio controller's DRP IEs is done after all the events in
 * an event buffer are processed.  This saves waiting multiple times
 * for the SET_DRP_IE command to complete.
 */
int uwbd_evt_handle_rc_drp(struct uwb_event *evt)
{
	struct device *dev = &evt->rc->uwb_dev.dev;
	struct uwb_rc *rc = evt->rc;
	struct uwb_rc_evt_drp *drp_evt;
	size_t ielength, bytes_left;
	struct uwb_dev_addr src_addr;
	struct uwb_dev *src_dev;
	int reason;

	/* Is there enough data to decode the event (and any IEs in
	   its payload)? */
	if (evt->notif.size < sizeof(*drp_evt)) {
		dev_err(dev, "DRP event: Not enough data to decode event "
			"[%zu bytes left, %zu needed]\n",
			evt->notif.size, sizeof(*drp_evt));
		return 0;
	}
	bytes_left = evt->notif.size - sizeof(*drp_evt);
	drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb);
	ielength = le16_to_cpu(drp_evt->ie_length);
	if (bytes_left != ielength) {
		dev_err(dev, "DRP event: Not enough data in payload [%zu"
			"bytes left, %zu declared in the event]\n",
			bytes_left, ielength);
		return 0;
	}

	memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr));
	src_dev = uwb_dev_get_by_devaddr(rc, &src_addr);
	if (!src_dev) {
		/*
		 * A DRP notification from an unrecognized device.
		 *
		 * This is probably from a WUSB device that doesn't
		 * have an EUI-48 and therefore doesn't show up in the
		 * UWB device database.  It's safe to simply ignore
		 * these.
		 */
		return 0;
	}

	mutex_lock(&rc->rsvs_mutex);

	reason = uwb_rc_evt_drp_reason(drp_evt);

	switch (reason) {
	case UWB_DRP_NOTIF_DRP_IE_RCVD:
		uwb_drp_process_all(rc, drp_evt, ielength, src_dev);
		break;
	case UWB_DRP_NOTIF_CONFLICT:
		uwb_drp_process_conflict_all(rc, drp_evt, ielength, src_dev);
		break;
	case UWB_DRP_NOTIF_TERMINATE:
		uwb_drp_terminate_all(rc, src_dev);
		break;
	default:
		dev_warn(dev, "ignored DRP event with reason code: %d\n", reason);
		break;
	}

	mutex_unlock(&rc->rsvs_mutex);

	uwb_dev_put(src_dev);
	return 0;
}