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8cc13a09 DV |
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/delay.h> | |
24 | #include "uwb-internal.h" | |
25 | ||
26 | /** | |
27 | * Construct and send the SET DRP IE | |
28 | * | |
29 | * @rc: UWB Host controller | |
30 | * @returns: >= 0 number of bytes still available in the beacon | |
31 | * < 0 errno code on error. | |
32 | * | |
33 | * See WUSB[8.6.2.7]: The host must set all the DRP IEs that it wants the | |
34 | * device to include in its beacon at the same time. We thus have to | |
35 | * traverse all reservations and include the DRP IEs of all PENDING | |
36 | * and NEGOTIATED reservations in a SET DRP command for transmission. | |
37 | * | |
38 | * A DRP Availability IE is appended. | |
39 | * | |
40 | * rc->uwb_dev.mutex is held | |
41 | * | |
42 | * FIXME We currently ignore the returned value indicating the remaining space | |
43 | * in beacon. This could be used to deny reservation requests earlier if | |
44 | * determined that they would cause the beacon space to be exceeded. | |
45 | */ | |
46 | static | |
47 | int uwb_rc_gen_send_drp_ie(struct uwb_rc *rc) | |
48 | { | |
49 | int result; | |
50 | struct device *dev = &rc->uwb_dev.dev; | |
51 | struct uwb_rc_cmd_set_drp_ie *cmd; | |
52 | struct uwb_rc_evt_set_drp_ie reply; | |
53 | struct uwb_rsv *rsv; | |
54 | int num_bytes = 0; | |
55 | u8 *IEDataptr; | |
56 | ||
57 | result = -ENOMEM; | |
58 | /* First traverse all reservations to determine memory needed. */ | |
59 | list_for_each_entry(rsv, &rc->reservations, rc_node) { | |
60 | if (rsv->drp_ie != NULL) | |
61 | num_bytes += rsv->drp_ie->hdr.length + 2; | |
62 | } | |
63 | num_bytes += sizeof(rc->drp_avail.ie); | |
64 | cmd = kzalloc(sizeof(*cmd) + num_bytes, GFP_KERNEL); | |
65 | if (cmd == NULL) | |
66 | goto error; | |
67 | cmd->rccb.bCommandType = UWB_RC_CET_GENERAL; | |
68 | cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_DRP_IE); | |
69 | cmd->wIELength = num_bytes; | |
70 | IEDataptr = (u8 *)&cmd->IEData[0]; | |
71 | ||
72 | /* Next traverse all reservations to place IEs in allocated memory. */ | |
73 | list_for_each_entry(rsv, &rc->reservations, rc_node) { | |
74 | if (rsv->drp_ie != NULL) { | |
75 | memcpy(IEDataptr, rsv->drp_ie, | |
76 | rsv->drp_ie->hdr.length + 2); | |
77 | IEDataptr += rsv->drp_ie->hdr.length + 2; | |
78 | } | |
79 | } | |
80 | memcpy(IEDataptr, &rc->drp_avail.ie, sizeof(rc->drp_avail.ie)); | |
81 | ||
82 | reply.rceb.bEventType = UWB_RC_CET_GENERAL; | |
83 | reply.rceb.wEvent = UWB_RC_CMD_SET_DRP_IE; | |
84 | result = uwb_rc_cmd(rc, "SET-DRP-IE", &cmd->rccb, | |
85 | sizeof(*cmd) + num_bytes, &reply.rceb, | |
86 | sizeof(reply)); | |
87 | if (result < 0) | |
88 | goto error_cmd; | |
89 | result = le16_to_cpu(reply.wRemainingSpace); | |
90 | if (reply.bResultCode != UWB_RC_RES_SUCCESS) { | |
91 | dev_err(&rc->uwb_dev.dev, "SET-DRP-IE: command execution " | |
92 | "failed: %s (%d). RemainingSpace in beacon " | |
93 | "= %d\n", uwb_rc_strerror(reply.bResultCode), | |
94 | reply.bResultCode, result); | |
95 | result = -EIO; | |
96 | } else { | |
97 | dev_dbg(dev, "SET-DRP-IE sent. RemainingSpace in beacon " | |
98 | "= %d.\n", result); | |
99 | result = 0; | |
100 | } | |
101 | error_cmd: | |
102 | kfree(cmd); | |
103 | error: | |
104 | return result; | |
105 | ||
106 | } | |
107 | /** | |
108 | * Send all DRP IEs associated with this host | |
109 | * | |
110 | * @returns: >= 0 number of bytes still available in the beacon | |
111 | * < 0 errno code on error. | |
112 | * | |
113 | * As per the protocol we obtain the host controller device lock to access | |
114 | * bandwidth structures. | |
115 | */ | |
116 | int uwb_rc_send_all_drp_ie(struct uwb_rc *rc) | |
117 | { | |
118 | int result; | |
119 | ||
120 | mutex_lock(&rc->uwb_dev.mutex); | |
121 | result = uwb_rc_gen_send_drp_ie(rc); | |
122 | mutex_unlock(&rc->uwb_dev.mutex); | |
123 | return result; | |
124 | } | |
125 | ||
126 | void uwb_drp_handle_timeout(struct uwb_rsv *rsv) | |
127 | { | |
128 | struct device *dev = &rsv->rc->uwb_dev.dev; | |
129 | ||
130 | dev_dbg(dev, "reservation timeout in state %s (%d)\n", | |
131 | uwb_rsv_state_str(rsv->state), rsv->state); | |
132 | ||
133 | switch (rsv->state) { | |
134 | case UWB_RSV_STATE_O_INITIATED: | |
135 | if (rsv->is_multicast) { | |
136 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); | |
137 | return; | |
138 | } | |
139 | break; | |
140 | case UWB_RSV_STATE_O_ESTABLISHED: | |
141 | if (rsv->is_multicast) | |
142 | return; | |
143 | break; | |
144 | default: | |
145 | break; | |
146 | } | |
147 | uwb_rsv_remove(rsv); | |
148 | } | |
149 | ||
150 | /* | |
151 | * Based on the DRP IE, transition a target reservation to a new | |
152 | * state. | |
153 | */ | |
154 | static void uwb_drp_process_target(struct uwb_rc *rc, struct uwb_rsv *rsv, | |
155 | struct uwb_ie_drp *drp_ie) | |
156 | { | |
157 | struct device *dev = &rc->uwb_dev.dev; | |
158 | int status; | |
159 | enum uwb_drp_reason reason_code; | |
160 | ||
161 | status = uwb_ie_drp_status(drp_ie); | |
162 | reason_code = uwb_ie_drp_reason_code(drp_ie); | |
163 | ||
164 | if (status) { | |
165 | switch (reason_code) { | |
166 | case UWB_DRP_REASON_ACCEPTED: | |
167 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED); | |
168 | break; | |
169 | case UWB_DRP_REASON_MODIFIED: | |
170 | dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", | |
171 | reason_code, status); | |
172 | break; | |
173 | default: | |
174 | dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", | |
175 | reason_code, status); | |
176 | } | |
177 | } else { | |
178 | switch (reason_code) { | |
179 | case UWB_DRP_REASON_ACCEPTED: | |
180 | /* New reservations are handled in uwb_rsv_find(). */ | |
181 | break; | |
182 | case UWB_DRP_REASON_DENIED: | |
183 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); | |
184 | break; | |
185 | case UWB_DRP_REASON_CONFLICT: | |
186 | case UWB_DRP_REASON_MODIFIED: | |
187 | dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", | |
188 | reason_code, status); | |
189 | break; | |
190 | default: | |
191 | dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", | |
192 | reason_code, status); | |
193 | } | |
194 | } | |
195 | } | |
196 | ||
197 | /* | |
198 | * Based on the DRP IE, transition an owner reservation to a new | |
199 | * state. | |
200 | */ | |
201 | static void uwb_drp_process_owner(struct uwb_rc *rc, struct uwb_rsv *rsv, | |
202 | struct uwb_ie_drp *drp_ie) | |
203 | { | |
204 | struct device *dev = &rc->uwb_dev.dev; | |
205 | int status; | |
206 | enum uwb_drp_reason reason_code; | |
207 | ||
208 | status = uwb_ie_drp_status(drp_ie); | |
209 | reason_code = uwb_ie_drp_reason_code(drp_ie); | |
210 | ||
211 | if (status) { | |
212 | switch (reason_code) { | |
213 | case UWB_DRP_REASON_ACCEPTED: | |
214 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED); | |
215 | break; | |
216 | case UWB_DRP_REASON_MODIFIED: | |
217 | dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", | |
218 | reason_code, status); | |
219 | break; | |
220 | default: | |
221 | dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", | |
222 | reason_code, status); | |
223 | } | |
224 | } else { | |
225 | switch (reason_code) { | |
226 | case UWB_DRP_REASON_PENDING: | |
227 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_PENDING); | |
228 | break; | |
229 | case UWB_DRP_REASON_DENIED: | |
230 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); | |
231 | break; | |
232 | case UWB_DRP_REASON_CONFLICT: | |
233 | case UWB_DRP_REASON_MODIFIED: | |
234 | dev_err(dev, "FIXME: unhandled reason code (%d/%d)\n", | |
235 | reason_code, status); | |
236 | break; | |
237 | default: | |
238 | dev_warn(dev, "ignoring invalid DRP IE state (%d/%d)\n", | |
239 | reason_code, status); | |
240 | } | |
241 | } | |
242 | } | |
243 | ||
244 | /* | |
245 | * Process a received DRP IE, it's either for a reservation owned by | |
246 | * the RC or targeted at it (or it's for a WUSB cluster reservation). | |
247 | */ | |
248 | static void uwb_drp_process(struct uwb_rc *rc, struct uwb_dev *src, | |
249 | struct uwb_ie_drp *drp_ie) | |
250 | { | |
251 | struct uwb_rsv *rsv; | |
252 | ||
253 | rsv = uwb_rsv_find(rc, src, drp_ie); | |
254 | if (!rsv) { | |
255 | /* | |
256 | * No reservation? It's either for a recently | |
257 | * terminated reservation; or the DRP IE couldn't be | |
258 | * processed (e.g., an invalid IE or out of memory). | |
259 | */ | |
260 | return; | |
261 | } | |
262 | ||
263 | /* | |
264 | * Do nothing with DRP IEs for reservations that have been | |
265 | * terminated. | |
266 | */ | |
267 | if (rsv->state == UWB_RSV_STATE_NONE) { | |
268 | uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); | |
269 | return; | |
270 | } | |
271 | ||
272 | if (uwb_ie_drp_owner(drp_ie)) | |
273 | uwb_drp_process_target(rc, rsv, drp_ie); | |
274 | else | |
275 | uwb_drp_process_owner(rc, rsv, drp_ie); | |
276 | } | |
277 | ||
278 | ||
279 | /* | |
280 | * Process all the DRP IEs (both DRP IEs and the DRP Availability IE) | |
281 | * from a device. | |
282 | */ | |
283 | static | |
284 | void uwb_drp_process_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt, | |
285 | size_t ielen, struct uwb_dev *src_dev) | |
286 | { | |
287 | struct device *dev = &rc->uwb_dev.dev; | |
288 | struct uwb_ie_hdr *ie_hdr; | |
289 | void *ptr; | |
290 | ||
291 | ptr = drp_evt->ie_data; | |
292 | for (;;) { | |
293 | ie_hdr = uwb_ie_next(&ptr, &ielen); | |
294 | if (!ie_hdr) | |
295 | break; | |
296 | ||
297 | switch (ie_hdr->element_id) { | |
298 | case UWB_IE_DRP_AVAILABILITY: | |
299 | /* FIXME: does something need to be done with this? */ | |
300 | break; | |
301 | case UWB_IE_DRP: | |
302 | uwb_drp_process(rc, src_dev, (struct uwb_ie_drp *)ie_hdr); | |
303 | break; | |
304 | default: | |
305 | dev_warn(dev, "unexpected IE in DRP notification\n"); | |
306 | break; | |
307 | } | |
308 | } | |
309 | ||
310 | if (ielen > 0) | |
311 | dev_warn(dev, "%d octets remaining in DRP notification\n", | |
312 | (int)ielen); | |
313 | } | |
314 | ||
315 | ||
316 | /* | |
317 | * Go through all the DRP IEs and find the ones that conflict with our | |
318 | * reservations. | |
319 | * | |
320 | * FIXME: must resolve the conflict according the the rules in | |
321 | * [ECMA-368]. | |
322 | */ | |
323 | static | |
324 | void uwb_drp_process_conflict_all(struct uwb_rc *rc, struct uwb_rc_evt_drp *drp_evt, | |
325 | size_t ielen, struct uwb_dev *src_dev) | |
326 | { | |
327 | struct device *dev = &rc->uwb_dev.dev; | |
328 | struct uwb_ie_hdr *ie_hdr; | |
329 | struct uwb_ie_drp *drp_ie; | |
330 | void *ptr; | |
331 | ||
332 | ptr = drp_evt->ie_data; | |
333 | for (;;) { | |
334 | ie_hdr = uwb_ie_next(&ptr, &ielen); | |
335 | if (!ie_hdr) | |
336 | break; | |
337 | ||
338 | drp_ie = container_of(ie_hdr, struct uwb_ie_drp, hdr); | |
339 | ||
340 | /* FIXME: check if this DRP IE conflicts. */ | |
341 | } | |
342 | ||
343 | if (ielen > 0) | |
344 | dev_warn(dev, "%d octets remaining in DRP notification\n", | |
345 | (int)ielen); | |
346 | } | |
347 | ||
348 | ||
349 | /* | |
350 | * Terminate all reservations owned by, or targeted at, 'uwb_dev'. | |
351 | */ | |
352 | static void uwb_drp_terminate_all(struct uwb_rc *rc, struct uwb_dev *uwb_dev) | |
353 | { | |
354 | struct uwb_rsv *rsv; | |
355 | ||
356 | list_for_each_entry(rsv, &rc->reservations, rc_node) { | |
357 | if (rsv->owner == uwb_dev | |
358 | || (rsv->target.type == UWB_RSV_TARGET_DEV && rsv->target.dev == uwb_dev)) | |
359 | uwb_rsv_remove(rsv); | |
360 | } | |
361 | } | |
362 | ||
363 | ||
364 | /** | |
365 | * uwbd_evt_handle_rc_drp - handle a DRP_IE event | |
366 | * @evt: the DRP_IE event from the radio controller | |
367 | * | |
368 | * This processes DRP notifications from the radio controller, either | |
369 | * initiating a new reservation or transitioning an existing | |
370 | * reservation into a different state. | |
371 | * | |
372 | * DRP notifications can occur for three different reasons: | |
373 | * | |
374 | * - UWB_DRP_NOTIF_DRP_IE_RECVD: one or more DRP IEs with the RC as | |
375 | * the target or source have been recieved. | |
376 | * | |
377 | * These DRP IEs could be new or for an existing reservation. | |
378 | * | |
379 | * If the DRP IE for an existing reservation ceases to be to | |
380 | * recieved for at least mMaxLostBeacons, the reservation should be | |
381 | * considered to be terminated. Note that the TERMINATE reason (see | |
382 | * below) may not always be signalled (e.g., the remote device has | |
383 | * two or more reservations established with the RC). | |
384 | * | |
385 | * - UWB_DRP_NOTIF_CONFLICT: DRP IEs from any device in the beacon | |
386 | * group conflict with the RC's reservations. | |
387 | * | |
388 | * - UWB_DRP_NOTIF_TERMINATE: DRP IEs are no longer being received | |
389 | * from a device (i.e., it's terminated all reservations). | |
390 | * | |
391 | * Only the software state of the reservations is changed; the setting | |
392 | * of the radio controller's DRP IEs is done after all the events in | |
393 | * an event buffer are processed. This saves waiting multiple times | |
394 | * for the SET_DRP_IE command to complete. | |
395 | */ | |
396 | int uwbd_evt_handle_rc_drp(struct uwb_event *evt) | |
397 | { | |
398 | struct device *dev = &evt->rc->uwb_dev.dev; | |
399 | struct uwb_rc *rc = evt->rc; | |
400 | struct uwb_rc_evt_drp *drp_evt; | |
401 | size_t ielength, bytes_left; | |
402 | struct uwb_dev_addr src_addr; | |
403 | struct uwb_dev *src_dev; | |
404 | int reason; | |
405 | ||
406 | /* Is there enough data to decode the event (and any IEs in | |
407 | its payload)? */ | |
408 | if (evt->notif.size < sizeof(*drp_evt)) { | |
409 | dev_err(dev, "DRP event: Not enough data to decode event " | |
410 | "[%zu bytes left, %zu needed]\n", | |
411 | evt->notif.size, sizeof(*drp_evt)); | |
412 | return 0; | |
413 | } | |
414 | bytes_left = evt->notif.size - sizeof(*drp_evt); | |
415 | drp_evt = container_of(evt->notif.rceb, struct uwb_rc_evt_drp, rceb); | |
416 | ielength = le16_to_cpu(drp_evt->ie_length); | |
417 | if (bytes_left != ielength) { | |
418 | dev_err(dev, "DRP event: Not enough data in payload [%zu" | |
419 | "bytes left, %zu declared in the event]\n", | |
420 | bytes_left, ielength); | |
421 | return 0; | |
422 | } | |
423 | ||
424 | memcpy(src_addr.data, &drp_evt->src_addr, sizeof(src_addr)); | |
425 | src_dev = uwb_dev_get_by_devaddr(rc, &src_addr); | |
426 | if (!src_dev) { | |
427 | /* | |
428 | * A DRP notification from an unrecognized device. | |
429 | * | |
430 | * This is probably from a WUSB device that doesn't | |
431 | * have an EUI-48 and therefore doesn't show up in the | |
432 | * UWB device database. It's safe to simply ignore | |
433 | * these. | |
434 | */ | |
435 | return 0; | |
436 | } | |
437 | ||
438 | mutex_lock(&rc->rsvs_mutex); | |
439 | ||
440 | reason = uwb_rc_evt_drp_reason(drp_evt); | |
441 | ||
442 | switch (reason) { | |
443 | case UWB_DRP_NOTIF_DRP_IE_RCVD: | |
444 | uwb_drp_process_all(rc, drp_evt, ielength, src_dev); | |
445 | break; | |
446 | case UWB_DRP_NOTIF_CONFLICT: | |
447 | uwb_drp_process_conflict_all(rc, drp_evt, ielength, src_dev); | |
448 | break; | |
449 | case UWB_DRP_NOTIF_TERMINATE: | |
450 | uwb_drp_terminate_all(rc, src_dev); | |
451 | break; | |
452 | default: | |
453 | dev_warn(dev, "ignored DRP event with reason code: %d\n", reason); | |
454 | break; | |
455 | } | |
456 | ||
457 | mutex_unlock(&rc->rsvs_mutex); | |
458 | ||
459 | uwb_dev_put(src_dev); | |
460 | return 0; | |
461 | } |