aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/uwb/est.c
blob: f3e232584284a906309247e5ed5f3c0fef54e472 (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
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
/*
 * Ultra Wide Band Radio Control
 * Event Size Tables management
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME: docs
 *
 * Infrastructure, code and data tables for guessing the size of
 * events received on the notification endpoints of UWB radio
 * controllers.
 *
 * You define a table of events and for each, its size and how to get
 * the extra size.
 *
 * ENTRY POINTS:
 *
 * uwb_est_{init/destroy}(): To initialize/release the EST subsystem.
 *
 * uwb_est_[u]register(): To un/register event size tables
 *   uwb_est_grow()
 *
 * uwb_est_find_size(): Get the size of an event
 *   uwb_est_get_size()
 */
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/export.h>

#include "uwb-internal.h"

struct uwb_est {
	u16 type_event_high;
	u16 vendor, product;
	u8 entries;
	const struct uwb_est_entry *entry;
};

static struct uwb_est *uwb_est;
static u8 uwb_est_size;
static u8 uwb_est_used;
static DEFINE_RWLOCK(uwb_est_lock);

/**
 * WUSB Standard Event Size Table, HWA-RC interface
 *
 * Sizes for events and notifications type 0 (general), high nibble 0.
 */
static
struct uwb_est_entry uwb_est_00_00xx[] = {
	[UWB_RC_EVT_IE_RCV] = {
		.size = sizeof(struct uwb_rc_evt_ie_rcv),
		.offset = 1 + offsetof(struct uwb_rc_evt_ie_rcv, wIELength),
	},
	[UWB_RC_EVT_BEACON] = {
		.size = sizeof(struct uwb_rc_evt_beacon),
		.offset = 1 + offsetof(struct uwb_rc_evt_beacon, wBeaconInfoLength),
	},
	[UWB_RC_EVT_BEACON_SIZE] = {
		.size = sizeof(struct uwb_rc_evt_beacon_size),
	},
	[UWB_RC_EVT_BPOIE_CHANGE] = {
		.size = sizeof(struct uwb_rc_evt_bpoie_change),
		.offset = 1 + offsetof(struct uwb_rc_evt_bpoie_change,
				       wBPOIELength),
	},
	[UWB_RC_EVT_BP_SLOT_CHANGE] = {
		.size = sizeof(struct uwb_rc_evt_bp_slot_change),
	},
	[UWB_RC_EVT_BP_SWITCH_IE_RCV] = {
		.size = sizeof(struct uwb_rc_evt_bp_switch_ie_rcv),
		.offset = 1 + offsetof(struct uwb_rc_evt_bp_switch_ie_rcv, wIELength),
	},
	[UWB_RC_EVT_DEV_ADDR_CONFLICT] = {
		.size = sizeof(struct uwb_rc_evt_dev_addr_conflict),
	},
	[UWB_RC_EVT_DRP_AVAIL] = {
		.size = sizeof(struct uwb_rc_evt_drp_avail)
	},
	[UWB_RC_EVT_DRP] = {
		.size = sizeof(struct uwb_rc_evt_drp),
		.offset = 1 + offsetof(struct uwb_rc_evt_drp, ie_length),
	},
	[UWB_RC_EVT_BP_SWITCH_STATUS] = {
		.size = sizeof(struct uwb_rc_evt_bp_switch_status),
	},
	[UWB_RC_EVT_CMD_FRAME_RCV] = {
		.size = sizeof(struct uwb_rc_evt_cmd_frame_rcv),
		.offset = 1 + offsetof(struct uwb_rc_evt_cmd_frame_rcv, dataLength),
	},
	[UWB_RC_EVT_CHANNEL_CHANGE_IE_RCV] = {
		.size = sizeof(struct uwb_rc_evt_channel_change_ie_rcv),
		.offset = 1 + offsetof(struct uwb_rc_evt_channel_change_ie_rcv, wIELength),
	},
	[UWB_RC_CMD_CHANNEL_CHANGE] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_DEV_ADDR_MGMT] = {
		.size = sizeof(struct uwb_rc_evt_dev_addr_mgmt) },
	[UWB_RC_CMD_GET_IE] = {
		.size = sizeof(struct uwb_rc_evt_get_ie),
		.offset = 1 + offsetof(struct uwb_rc_evt_get_ie, wIELength),
	},
	[UWB_RC_CMD_RESET] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SCAN] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SET_BEACON_FILTER] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SET_DRP_IE] = {
		.size = sizeof(struct uwb_rc_evt_set_drp_ie),
	},
	[UWB_RC_CMD_SET_IE] = {
		.size = sizeof(struct uwb_rc_evt_set_ie),
	},
	[UWB_RC_CMD_SET_NOTIFICATION_FILTER] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SET_TX_POWER] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SLEEP] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_START_BEACON] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_STOP_BEACON] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_BP_MERGE] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SEND_COMMAND_FRAME] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
	[UWB_RC_CMD_SET_ASIE_NOTIF] = {
		.size = sizeof(struct uwb_rc_evt_confirm),
	},
};

static
struct uwb_est_entry uwb_est_01_00xx[] = {
	[UWB_RC_DAA_ENERGY_DETECTED] = {
		.size = sizeof(struct uwb_rc_evt_daa_energy_detected),
	},
	[UWB_RC_SET_DAA_ENERGY_MASK] = {
		.size = sizeof(struct uwb_rc_evt_set_daa_energy_mask),
	},
	[UWB_RC_SET_NOTIFICATION_FILTER_EX] = {
		.size = sizeof(struct uwb_rc_evt_set_notification_filter_ex),
	},
};

/**
 * Initialize the EST subsystem
 *
 * Register the standard tables also.
 *
 * FIXME: tag init
 */
int uwb_est_create(void)
{
	int result;

	uwb_est_size = 2;
	uwb_est_used = 0;
	uwb_est = kcalloc(uwb_est_size, sizeof(uwb_est[0]), GFP_KERNEL);
	if (uwb_est == NULL)
		return -ENOMEM;

	result = uwb_est_register(UWB_RC_CET_GENERAL, 0, 0xffff, 0xffff,
				  uwb_est_00_00xx, ARRAY_SIZE(uwb_est_00_00xx));
	if (result < 0)
		goto out;
	result = uwb_est_register(UWB_RC_CET_EX_TYPE_1, 0, 0xffff, 0xffff,
				  uwb_est_01_00xx, ARRAY_SIZE(uwb_est_01_00xx));
out:
	return result;
}


/** Clean it up */
void uwb_est_destroy(void)
{
	kfree(uwb_est);
	uwb_est = NULL;
	uwb_est_size = uwb_est_used = 0;
}


/**
 * Double the capacity of the EST table
 *
 * @returns 0 if ok, < 0 errno no error.
 */
static
int uwb_est_grow(void)
{
	size_t actual_size = uwb_est_size * sizeof(uwb_est[0]);
	void *new = kmalloc(2 * actual_size, GFP_ATOMIC);
	if (new == NULL)
		return -ENOMEM;
	memcpy(new, uwb_est, actual_size);
	memset(new + actual_size, 0, actual_size);
	kfree(uwb_est);
	uwb_est = new;
	uwb_est_size *= 2;
	return 0;
}


/**
 * Register an event size table
 *
 * Makes room for it if the table is full, and then inserts  it in the
 * right position (entries are sorted by type, event_high, vendor and
 * then product).
 *
 * @vendor:  vendor code for matching against the device (0x0000 and
 *           0xffff mean any); use 0x0000 to force all to match without
 *           checking possible vendor specific ones, 0xfffff to match
 *           after checking vendor specific ones.
 *
 * @product: product code from that vendor; same matching rules, use
 *           0x0000 for not allowing vendor specific matches, 0xffff
 *           for allowing.
 *
 * This arragement just makes the tables sort differenty. Because the
 * table is sorted by growing type-event_high-vendor-product, a zero
 * vendor will match before than a 0x456a vendor, that will match
 * before a 0xfffff vendor.
 *
 * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 */
/* FIXME: add bus type to vendor/product code */
int uwb_est_register(u8 type, u8 event_high, u16 vendor, u16 product,
		     const struct uwb_est_entry *entry, size_t entries)
{
	unsigned long flags;
	unsigned itr;
	int result = 0;

	write_lock_irqsave(&uwb_est_lock, flags);
	if (uwb_est_used == uwb_est_size) {
		result = uwb_est_grow();
		if (result < 0)
			goto out;
	}
	/* Find the right spot to insert it in */
	for (itr = 0; itr < uwb_est_used; itr++)
		if (uwb_est[itr].type_event_high < type
		    && uwb_est[itr].vendor < vendor
		    && uwb_est[itr].product < product)
			break;

	/* Shift others to make room for the new one? */
	if (itr < uwb_est_used)
		memmove(&uwb_est[itr+1], &uwb_est[itr], uwb_est_used - itr);
	uwb_est[itr].type_event_high = type << 8 | event_high;
	uwb_est[itr].vendor = vendor;
	uwb_est[itr].product = product;
	uwb_est[itr].entry = entry;
	uwb_est[itr].entries = entries;
	uwb_est_used++;
out:
	write_unlock_irqrestore(&uwb_est_lock, flags);
	return result;
}
EXPORT_SYMBOL_GPL(uwb_est_register);


/**
 * Unregister an event size table
 *
 * This just removes the specified entry and moves the ones after it
 * to fill in the gap. This is needed to keep the list sorted; no
 * reallocation is done to reduce the size of the table.
 *
 * We unregister by all the data we used to register instead of by
 * pointer to the @entry array because we might have used the same
 * table for a bunch of IDs (for example).
 *
 * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
 */
int uwb_est_unregister(u8 type, u8 event_high, u16 vendor, u16 product,
		       const struct uwb_est_entry *entry, size_t entries)
{
	unsigned long flags;
	unsigned itr;
	struct uwb_est est_cmp = {
		.type_event_high = type << 8 | event_high,
		.vendor = vendor,
		.product = product,
		.entry = entry,
		.entries = entries
	};
	write_lock_irqsave(&uwb_est_lock, flags);
	for (itr = 0; itr < uwb_est_used; itr++)
		if (!memcmp(&uwb_est[itr], &est_cmp, sizeof(est_cmp)))
			goto found;
	write_unlock_irqrestore(&uwb_est_lock, flags);
	return -ENOENT;

found:
	if (itr < uwb_est_used - 1)	/* Not last one? move ones above */
		memmove(&uwb_est[itr], &uwb_est[itr+1], uwb_est_used - itr - 1);
	uwb_est_used--;
	write_unlock_irqrestore(&uwb_est_lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(uwb_est_unregister);


/**
 * Get the size of an event from a table
 *
 * @rceb: pointer to the buffer with the event
 * @rceb_size: size of the area pointed to by @rceb in bytes.
 * @returns: > 0      Size of the event
 *	     -ENOSPC  An area big enough was not provided to look
 *		      ahead into the event's guts and guess the size.
 *	     -EINVAL  Unknown event code (wEvent).
 *
 * This will look at the received RCEB and guess what is the total
 * size. For variable sized events, it will look further ahead into
 * their length field to see how much data should be read.
 *
 * Note this size is *not* final--the neh (Notification/Event Handle)
 * might specificy an extra size to add.
 */
static
ssize_t uwb_est_get_size(struct uwb_rc *uwb_rc, struct uwb_est *est,
			 u8 event_low, const struct uwb_rceb *rceb,
			 size_t rceb_size)
{
	unsigned offset;
	ssize_t size;
	struct device *dev = &uwb_rc->uwb_dev.dev;
	const struct uwb_est_entry *entry;

	size = -ENOENT;
	if (event_low >= est->entries) {	/* in range? */
		dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u out of range\n",
			est, est->type_event_high, est->vendor, est->product,
			est->entries, event_low);
		goto out;
	}
	size = -ENOENT;
	entry = &est->entry[event_low];
	if (entry->size == 0 && entry->offset == 0) {	/* unknown? */
		dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u unknown\n",
			est, est->type_event_high, est->vendor,	est->product,
			est->entries, event_low);
		goto out;
	}
	offset = entry->offset;	/* extra fries with that? */
	if (offset == 0)
		size = entry->size;
	else {
		/* Ops, got an extra size field at 'offset'--read it */
		const void *ptr = rceb;
		size_t type_size = 0;
		offset--;
		size = -ENOSPC;			/* enough data for more? */
		switch (entry->type) {
		case UWB_EST_16:  type_size = sizeof(__le16); break;
		case UWB_EST_8:   type_size = sizeof(u8);     break;
		default: 	 BUG();
		}
		if (offset + type_size > rceb_size) {
			dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
				"not enough data to read extra size\n",
				est, est->type_event_high, est->vendor,
				est->product, est->entries);
			goto out;
		}
		size = entry->size;
		ptr += offset;
		switch (entry->type) {
		case UWB_EST_16:  size += le16_to_cpu(*(__le16 *)ptr); break;
		case UWB_EST_8:   size += *(u8 *)ptr;                  break;
		default: 	 BUG();
		}
	}
out:
	return size;
}


/**
 * Guesses the size of a WA event
 *
 * @rceb: pointer to the buffer with the event
 * @rceb_size: size of the area pointed to by @rceb in bytes.
 * @returns: > 0      Size of the event
 *	     -ENOSPC  An area big enough was not provided to look
 *		      ahead into the event's guts and guess the size.
 *	     -EINVAL  Unknown event code (wEvent).
 *
 * This will look at the received RCEB and guess what is the total
 * size by checking all the tables registered with
 * uwb_est_register(). For variable sized events, it will look further
 * ahead into their length field to see how much data should be read.
 *
 * Note this size is *not* final--the neh (Notification/Event Handle)
 * might specificy an extra size to add or replace.
 */
ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
			  size_t rceb_size)
{
	/* FIXME: add vendor/product data */
	ssize_t size;
	struct device *dev = &rc->uwb_dev.dev;
	unsigned long flags;
	unsigned itr;
	u16 type_event_high, event;

	read_lock_irqsave(&uwb_est_lock, flags);
	size = -ENOSPC;
	if (rceb_size < sizeof(*rceb))
		goto out;
	event = le16_to_cpu(rceb->wEvent);
	type_event_high = rceb->bEventType << 8 | (event & 0xff00) >> 8;
	for (itr = 0; itr < uwb_est_used; itr++) {
		if (uwb_est[itr].type_event_high != type_event_high)
			continue;
		size = uwb_est_get_size(rc, &uwb_est[itr],
					event & 0x00ff, rceb, rceb_size);
		/* try more tables that might handle the same type */
		if (size != -ENOENT)
			goto out;
	}
	dev_dbg(dev,
		"event 0x%02x/%04x/%02x: no handlers available; RCEB %4ph\n",
		(unsigned) rceb->bEventType,
		(unsigned) le16_to_cpu(rceb->wEvent),
		(unsigned) rceb->bEventContext,
		rceb);
	size = -ENOENT;
out:
	read_unlock_irqrestore(&uwb_est_lock, flags);
	return size;
}
EXPORT_SYMBOL_GPL(uwb_est_find_size);