1 /*
2 * Ultra Wide Band
3 * Life cycle of radio controllers
4 *
5 * Copyright (C) 2005-2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version
10 * 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 * 02110-1301, USA.
21 *
22 *
23 * FIXME: docs
24 *
25 * A UWB radio controller is also a UWB device, so it embeds one...
26 *
27 * List of RCs comes from the 'struct class uwb_rc_class'.
28 */
29
30 #include <linux/kernel.h>
31 #include <linux/string.h>
32 #include <linux/device.h>
33 #include <linux/err.h>
34 #include <linux/random.h>
35 #include <linux/kdev_t.h>
36 #include <linux/etherdevice.h>
37 #include <linux/usb.h>
38 #include <linux/slab.h>
39 #include <linux/export.h>
40
41 #include "uwb-internal.h"
42
uwb_rc_index_match(struct device * dev,const void * data)43 static int uwb_rc_index_match(struct device *dev, const void *data)
44 {
45 const int *index = data;
46 struct uwb_rc *rc = dev_get_drvdata(dev);
47
48 if (rc->index == *index)
49 return 1;
50 return 0;
51 }
52
uwb_rc_find_by_index(int index)53 static struct uwb_rc *uwb_rc_find_by_index(int index)
54 {
55 struct device *dev;
56 struct uwb_rc *rc = NULL;
57
58 dev = class_find_device(&uwb_rc_class, NULL, &index, uwb_rc_index_match);
59 if (dev)
60 rc = dev_get_drvdata(dev);
61 return rc;
62 }
63
uwb_rc_new_index(void)64 static int uwb_rc_new_index(void)
65 {
66 int index = 0;
67
68 for (;;) {
69 if (!uwb_rc_find_by_index(index))
70 return index;
71 if (++index < 0)
72 index = 0;
73 }
74 }
75
76 /**
77 * Release the backing device of a uwb_rc that has been dynamically allocated.
78 */
uwb_rc_sys_release(struct device * dev)79 static void uwb_rc_sys_release(struct device *dev)
80 {
81 struct uwb_dev *uwb_dev = container_of(dev, struct uwb_dev, dev);
82 struct uwb_rc *rc = container_of(uwb_dev, struct uwb_rc, uwb_dev);
83
84 uwb_rc_ie_release(rc);
85 kfree(rc);
86 }
87
88
uwb_rc_init(struct uwb_rc * rc)89 void uwb_rc_init(struct uwb_rc *rc)
90 {
91 struct uwb_dev *uwb_dev = &rc->uwb_dev;
92
93 uwb_dev_init(uwb_dev);
94 rc->uwb_dev.dev.class = &uwb_rc_class;
95 rc->uwb_dev.dev.release = uwb_rc_sys_release;
96 uwb_rc_neh_create(rc);
97 rc->beaconing = -1;
98 rc->scan_type = UWB_SCAN_DISABLED;
99 INIT_LIST_HEAD(&rc->notifs_chain.list);
100 mutex_init(&rc->notifs_chain.mutex);
101 INIT_LIST_HEAD(&rc->uwb_beca.list);
102 mutex_init(&rc->uwb_beca.mutex);
103 uwb_drp_avail_init(rc);
104 uwb_rc_ie_init(rc);
105 uwb_rsv_init(rc);
106 uwb_rc_pal_init(rc);
107 }
108 EXPORT_SYMBOL_GPL(uwb_rc_init);
109
110
uwb_rc_alloc(void)111 struct uwb_rc *uwb_rc_alloc(void)
112 {
113 struct uwb_rc *rc;
114 rc = kzalloc(sizeof(*rc), GFP_KERNEL);
115 if (rc == NULL)
116 return NULL;
117 uwb_rc_init(rc);
118 return rc;
119 }
120 EXPORT_SYMBOL_GPL(uwb_rc_alloc);
121
122 /*
123 * Show the ASIE that is broadcast in the UWB beacon by this uwb_rc device.
124 */
ASIE_show(struct device * dev,struct device_attribute * attr,char * buf)125 static ssize_t ASIE_show(struct device *dev,
126 struct device_attribute *attr, char *buf)
127 {
128 struct uwb_dev *uwb_dev = to_uwb_dev(dev);
129 struct uwb_rc *rc = uwb_dev->rc;
130 struct uwb_ie_hdr *ie;
131 void *ptr;
132 size_t len;
133 int result = 0;
134
135 /* init empty buffer. */
136 result = scnprintf(buf, PAGE_SIZE, "\n");
137 mutex_lock(&rc->ies_mutex);
138 /* walk IEData looking for an ASIE. */
139 ptr = rc->ies->IEData;
140 len = le16_to_cpu(rc->ies->wIELength);
141 for (;;) {
142 ie = uwb_ie_next(&ptr, &len);
143 if (!ie)
144 break;
145 if (ie->element_id == UWB_APP_SPEC_IE) {
146 result = uwb_ie_dump_hex(ie,
147 ie->length + sizeof(struct uwb_ie_hdr),
148 buf, PAGE_SIZE);
149 break;
150 }
151 }
152 mutex_unlock(&rc->ies_mutex);
153
154 return result;
155 }
156
157 /*
158 * Update the ASIE that is broadcast in the UWB beacon by this uwb_rc device.
159 */
ASIE_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)160 static ssize_t ASIE_store(struct device *dev,
161 struct device_attribute *attr,
162 const char *buf, size_t size)
163 {
164 struct uwb_dev *uwb_dev = to_uwb_dev(dev);
165 struct uwb_rc *rc = uwb_dev->rc;
166 char ie_buf[255];
167 int result, ie_len = 0;
168 const char *cur_ptr = buf;
169 struct uwb_ie_hdr *ie;
170
171 /* empty string means clear the ASIE. */
172 if (strlen(buf) <= 1) {
173 uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);
174 return size;
175 }
176
177 /* if non-empty string, convert string of hex chars to binary. */
178 while (ie_len < sizeof(ie_buf)) {
179 int char_count;
180
181 if (sscanf(cur_ptr, " %02hhX %n",
182 &(ie_buf[ie_len]), &char_count) > 0) {
183 ++ie_len;
184 /* skip chars read from cur_ptr. */
185 cur_ptr += char_count;
186 } else {
187 break;
188 }
189 }
190
191 /* validate IE length and type. */
192 if (ie_len < sizeof(struct uwb_ie_hdr)) {
193 dev_err(dev, "%s: Invalid ASIE size %d.\n", __func__, ie_len);
194 return -EINVAL;
195 }
196
197 ie = (struct uwb_ie_hdr *)ie_buf;
198 if (ie->element_id != UWB_APP_SPEC_IE) {
199 dev_err(dev, "%s: Invalid IE element type size = 0x%02X.\n",
200 __func__, ie->element_id);
201 return -EINVAL;
202 }
203
204 /* bounds check length field from user. */
205 if (ie->length > (ie_len - sizeof(struct uwb_ie_hdr)))
206 ie->length = ie_len - sizeof(struct uwb_ie_hdr);
207
208 /*
209 * Valid ASIE received. Remove current ASIE then add the new one using
210 * uwb_rc_ie_add.
211 */
212 uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);
213
214 result = uwb_rc_ie_add(rc, ie, ie->length + sizeof(struct uwb_ie_hdr));
215
216 return result >= 0 ? size : result;
217 }
218 static DEVICE_ATTR_RW(ASIE);
219
220 static struct attribute *rc_attrs[] = {
221 &dev_attr_mac_address.attr,
222 &dev_attr_scan.attr,
223 &dev_attr_beacon.attr,
224 &dev_attr_ASIE.attr,
225 NULL,
226 };
227
228 static struct attribute_group rc_attr_group = {
229 .attrs = rc_attrs,
230 };
231
232 /*
233 * Registration of sysfs specific stuff
234 */
uwb_rc_sys_add(struct uwb_rc * rc)235 static int uwb_rc_sys_add(struct uwb_rc *rc)
236 {
237 return sysfs_create_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
238 }
239
240
__uwb_rc_sys_rm(struct uwb_rc * rc)241 static void __uwb_rc_sys_rm(struct uwb_rc *rc)
242 {
243 sysfs_remove_group(&rc->uwb_dev.dev.kobj, &rc_attr_group);
244 }
245
246 /**
247 * uwb_rc_mac_addr_setup - get an RC's EUI-48 address or set it
248 * @rc: the radio controller.
249 *
250 * If the EUI-48 address is 00:00:00:00:00:00 or FF:FF:FF:FF:FF:FF
251 * then a random locally administered EUI-48 is generated and set on
252 * the device. The probability of address collisions is sufficiently
253 * unlikely (1/2^40 = 9.1e-13) that they're not checked for.
254 */
255 static
uwb_rc_mac_addr_setup(struct uwb_rc * rc)256 int uwb_rc_mac_addr_setup(struct uwb_rc *rc)
257 {
258 int result;
259 struct device *dev = &rc->uwb_dev.dev;
260 struct uwb_dev *uwb_dev = &rc->uwb_dev;
261 char devname[UWB_ADDR_STRSIZE];
262 struct uwb_mac_addr addr;
263
264 result = uwb_rc_mac_addr_get(rc, &addr);
265 if (result < 0) {
266 dev_err(dev, "cannot retrieve UWB EUI-48 address: %d\n", result);
267 return result;
268 }
269
270 if (uwb_mac_addr_unset(&addr) || uwb_mac_addr_bcast(&addr)) {
271 addr.data[0] = 0x02; /* locally administered and unicast */
272 get_random_bytes(&addr.data[1], sizeof(addr.data)-1);
273
274 result = uwb_rc_mac_addr_set(rc, &addr);
275 if (result < 0) {
276 uwb_mac_addr_print(devname, sizeof(devname), &addr);
277 dev_err(dev, "cannot set EUI-48 address %s: %d\n",
278 devname, result);
279 return result;
280 }
281 }
282 uwb_dev->mac_addr = addr;
283 return 0;
284 }
285
286
287
uwb_rc_setup(struct uwb_rc * rc)288 static int uwb_rc_setup(struct uwb_rc *rc)
289 {
290 int result;
291 struct device *dev = &rc->uwb_dev.dev;
292
293 result = uwb_radio_setup(rc);
294 if (result < 0) {
295 dev_err(dev, "cannot setup UWB radio: %d\n", result);
296 goto error;
297 }
298 result = uwb_rc_mac_addr_setup(rc);
299 if (result < 0) {
300 dev_err(dev, "cannot setup UWB MAC address: %d\n", result);
301 goto error;
302 }
303 result = uwb_rc_dev_addr_assign(rc);
304 if (result < 0) {
305 dev_err(dev, "cannot assign UWB DevAddr: %d\n", result);
306 goto error;
307 }
308 result = uwb_rc_ie_setup(rc);
309 if (result < 0) {
310 dev_err(dev, "cannot setup IE subsystem: %d\n", result);
311 goto error_ie_setup;
312 }
313 result = uwb_rsv_setup(rc);
314 if (result < 0) {
315 dev_err(dev, "cannot setup reservation subsystem: %d\n", result);
316 goto error_rsv_setup;
317 }
318 uwb_dbg_add_rc(rc);
319 return 0;
320
321 error_rsv_setup:
322 uwb_rc_ie_release(rc);
323 error_ie_setup:
324 error:
325 return result;
326 }
327
328
329 /**
330 * Register a new UWB radio controller
331 *
332 * Did you call uwb_rc_init() on your rc?
333 *
334 * We assume that this is being called with a > 0 refcount on
335 * it [through ops->{get|put}_device(). We'll take our own, though.
336 *
337 * @parent_dev is our real device, the one that provides the actual UWB device
338 */
uwb_rc_add(struct uwb_rc * rc,struct device * parent_dev,void * priv)339 int uwb_rc_add(struct uwb_rc *rc, struct device *parent_dev, void *priv)
340 {
341 int result;
342 struct device *dev;
343 char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
344
345 rc->index = uwb_rc_new_index();
346
347 dev = &rc->uwb_dev.dev;
348 dev_set_name(dev, "uwb%d", rc->index);
349
350 rc->priv = priv;
351
352 init_waitqueue_head(&rc->uwbd.wq);
353 INIT_LIST_HEAD(&rc->uwbd.event_list);
354 spin_lock_init(&rc->uwbd.event_list_lock);
355
356 uwbd_start(rc);
357
358 result = rc->start(rc);
359 if (result < 0)
360 goto error_rc_start;
361
362 result = uwb_rc_setup(rc);
363 if (result < 0) {
364 dev_err(dev, "cannot setup UWB radio controller: %d\n", result);
365 goto error_rc_setup;
366 }
367
368 result = uwb_dev_add(&rc->uwb_dev, parent_dev, rc);
369 if (result < 0 && result != -EADDRNOTAVAIL)
370 goto error_dev_add;
371
372 result = uwb_rc_sys_add(rc);
373 if (result < 0) {
374 dev_err(parent_dev, "cannot register UWB radio controller "
375 "dev attributes: %d\n", result);
376 goto error_sys_add;
377 }
378
379 uwb_mac_addr_print(macbuf, sizeof(macbuf), &rc->uwb_dev.mac_addr);
380 uwb_dev_addr_print(devbuf, sizeof(devbuf), &rc->uwb_dev.dev_addr);
381 dev_info(dev,
382 "new uwb radio controller (mac %s dev %s) on %s %s\n",
383 macbuf, devbuf, parent_dev->bus->name, dev_name(parent_dev));
384 rc->ready = 1;
385 return 0;
386
387 error_sys_add:
388 uwb_dev_rm(&rc->uwb_dev);
389 error_dev_add:
390 error_rc_setup:
391 rc->stop(rc);
392 error_rc_start:
393 uwbd_stop(rc);
394 return result;
395 }
396 EXPORT_SYMBOL_GPL(uwb_rc_add);
397
398
uwb_dev_offair_helper(struct device * dev,void * priv)399 static int uwb_dev_offair_helper(struct device *dev, void *priv)
400 {
401 struct uwb_dev *uwb_dev = to_uwb_dev(dev);
402
403 return __uwb_dev_offair(uwb_dev, uwb_dev->rc);
404 }
405
406 /*
407 * Remove a Radio Controller; stop beaconing/scanning, disconnect all children
408 */
uwb_rc_rm(struct uwb_rc * rc)409 void uwb_rc_rm(struct uwb_rc *rc)
410 {
411 rc->ready = 0;
412
413 uwb_dbg_del_rc(rc);
414 uwb_rsv_remove_all(rc);
415 uwb_radio_shutdown(rc);
416
417 rc->stop(rc);
418
419 uwbd_stop(rc);
420 uwb_rc_neh_destroy(rc);
421
422 uwb_dev_lock(&rc->uwb_dev);
423 rc->priv = NULL;
424 rc->cmd = NULL;
425 uwb_dev_unlock(&rc->uwb_dev);
426 mutex_lock(&rc->uwb_beca.mutex);
427 uwb_dev_for_each(rc, uwb_dev_offair_helper, NULL);
428 __uwb_rc_sys_rm(rc);
429 mutex_unlock(&rc->uwb_beca.mutex);
430 uwb_rsv_cleanup(rc);
431 uwb_beca_release(rc);
432 uwb_dev_rm(&rc->uwb_dev);
433 }
434 EXPORT_SYMBOL_GPL(uwb_rc_rm);
435
find_rc_try_get(struct device * dev,const void * data)436 static int find_rc_try_get(struct device *dev, const void *data)
437 {
438 const struct uwb_rc *target_rc = data;
439 struct uwb_rc *rc = dev_get_drvdata(dev);
440
441 if (rc == NULL) {
442 WARN_ON(1);
443 return 0;
444 }
445 if (rc == target_rc) {
446 if (rc->ready == 0)
447 return 0;
448 else
449 return 1;
450 }
451 return 0;
452 }
453
454 /**
455 * Given a radio controller descriptor, validate and refcount it
456 *
457 * @returns NULL if the rc does not exist or is quiescing; the ptr to
458 * it otherwise.
459 */
__uwb_rc_try_get(struct uwb_rc * target_rc)460 struct uwb_rc *__uwb_rc_try_get(struct uwb_rc *target_rc)
461 {
462 struct device *dev;
463 struct uwb_rc *rc = NULL;
464
465 dev = class_find_device(&uwb_rc_class, NULL, target_rc,
466 find_rc_try_get);
467 if (dev) {
468 rc = dev_get_drvdata(dev);
469 __uwb_rc_get(rc);
470 }
471 return rc;
472 }
473 EXPORT_SYMBOL_GPL(__uwb_rc_try_get);
474
475 /*
476 * RC get for external refcount acquirers...
477 *
478 * Increments the refcount of the device and it's backend modules
479 */
uwb_rc_get(struct uwb_rc * rc)480 static inline struct uwb_rc *uwb_rc_get(struct uwb_rc *rc)
481 {
482 if (rc->ready == 0)
483 return NULL;
484 uwb_dev_get(&rc->uwb_dev);
485 return rc;
486 }
487
find_rc_grandpa(struct device * dev,const void * data)488 static int find_rc_grandpa(struct device *dev, const void *data)
489 {
490 const struct device *grandpa_dev = data;
491 struct uwb_rc *rc = dev_get_drvdata(dev);
492
493 if (rc->uwb_dev.dev.parent->parent == grandpa_dev) {
494 rc = uwb_rc_get(rc);
495 return 1;
496 }
497 return 0;
498 }
499
500 /**
501 * Locate and refcount a radio controller given a common grand-parent
502 *
503 * @grandpa_dev Pointer to the 'grandparent' device structure.
504 * @returns NULL If the rc does not exist or is quiescing; the ptr to
505 * it otherwise, properly referenced.
506 *
507 * The Radio Control interface (or the UWB Radio Controller) is always
508 * an interface of a device. The parent is the interface, the
509 * grandparent is the device that encapsulates the interface.
510 *
511 * There is no need to lock around as the "grandpa" would be
512 * refcounted by the target, and to remove the referemes, the
513 * uwb_rc_class->sem would have to be taken--we hold it, ergo we
514 * should be safe.
515 */
uwb_rc_get_by_grandpa(const struct device * grandpa_dev)516 struct uwb_rc *uwb_rc_get_by_grandpa(const struct device *grandpa_dev)
517 {
518 struct device *dev;
519 struct uwb_rc *rc = NULL;
520
521 dev = class_find_device(&uwb_rc_class, NULL, grandpa_dev,
522 find_rc_grandpa);
523 if (dev)
524 rc = dev_get_drvdata(dev);
525 return rc;
526 }
527 EXPORT_SYMBOL_GPL(uwb_rc_get_by_grandpa);
528
529 /**
530 * Find a radio controller by device address
531 *
532 * @returns the pointer to the radio controller, properly referenced
533 */
find_rc_dev(struct device * dev,const void * data)534 static int find_rc_dev(struct device *dev, const void *data)
535 {
536 const struct uwb_dev_addr *addr = data;
537 struct uwb_rc *rc = dev_get_drvdata(dev);
538
539 if (rc == NULL) {
540 WARN_ON(1);
541 return 0;
542 }
543 if (!uwb_dev_addr_cmp(&rc->uwb_dev.dev_addr, addr)) {
544 rc = uwb_rc_get(rc);
545 return 1;
546 }
547 return 0;
548 }
549
uwb_rc_get_by_dev(const struct uwb_dev_addr * addr)550 struct uwb_rc *uwb_rc_get_by_dev(const struct uwb_dev_addr *addr)
551 {
552 struct device *dev;
553 struct uwb_rc *rc = NULL;
554
555 dev = class_find_device(&uwb_rc_class, NULL, addr, find_rc_dev);
556 if (dev)
557 rc = dev_get_drvdata(dev);
558
559 return rc;
560 }
561 EXPORT_SYMBOL_GPL(uwb_rc_get_by_dev);
562
563 /**
564 * Drop a reference on a radio controller
565 *
566 * This is the version that should be done by entities external to the
567 * UWB Radio Control stack (ie: clients of the API).
568 */
uwb_rc_put(struct uwb_rc * rc)569 void uwb_rc_put(struct uwb_rc *rc)
570 {
571 __uwb_rc_put(rc);
572 }
573 EXPORT_SYMBOL_GPL(uwb_rc_put);
574