1/*
2 * Ultra Wide Band Radio Control
3 * Event Size Tables management
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 * Infrastructure, code and data tables for guessing the size of
26 * events received on the notification endpoints of UWB radio
27 * controllers.
28 *
29 * You define a table of events and for each, its size and how to get
30 * the extra size.
31 *
32 * ENTRY POINTS:
33 *
34 * uwb_est_{init/destroy}(): To initialize/release the EST subsystem.
35 *
36 * uwb_est_[u]register(): To un/register event size tables
37 *   uwb_est_grow()
38 *
39 * uwb_est_find_size(): Get the size of an event
40 *   uwb_est_get_size()
41 */
42#include <linux/spinlock.h>
43#include <linux/slab.h>
44#include <linux/export.h>
45
46#include "uwb-internal.h"
47
48struct uwb_est {
49	u16 type_event_high;
50	u16 vendor, product;
51	u8 entries;
52	const struct uwb_est_entry *entry;
53};
54
55static struct uwb_est *uwb_est;
56static u8 uwb_est_size;
57static u8 uwb_est_used;
58static DEFINE_RWLOCK(uwb_est_lock);
59
60/**
61 * WUSB Standard Event Size Table, HWA-RC interface
62 *
63 * Sizes for events and notifications type 0 (general), high nibble 0.
64 */
65static
66struct uwb_est_entry uwb_est_00_00xx[] = {
67	[UWB_RC_EVT_IE_RCV] = {
68		.size = sizeof(struct uwb_rc_evt_ie_rcv),
69		.offset = 1 + offsetof(struct uwb_rc_evt_ie_rcv, wIELength),
70	},
71	[UWB_RC_EVT_BEACON] = {
72		.size = sizeof(struct uwb_rc_evt_beacon),
73		.offset = 1 + offsetof(struct uwb_rc_evt_beacon, wBeaconInfoLength),
74	},
75	[UWB_RC_EVT_BEACON_SIZE] = {
76		.size = sizeof(struct uwb_rc_evt_beacon_size),
77	},
78	[UWB_RC_EVT_BPOIE_CHANGE] = {
79		.size = sizeof(struct uwb_rc_evt_bpoie_change),
80		.offset = 1 + offsetof(struct uwb_rc_evt_bpoie_change,
81				       wBPOIELength),
82	},
83	[UWB_RC_EVT_BP_SLOT_CHANGE] = {
84		.size = sizeof(struct uwb_rc_evt_bp_slot_change),
85	},
86	[UWB_RC_EVT_BP_SWITCH_IE_RCV] = {
87		.size = sizeof(struct uwb_rc_evt_bp_switch_ie_rcv),
88		.offset = 1 + offsetof(struct uwb_rc_evt_bp_switch_ie_rcv, wIELength),
89	},
90	[UWB_RC_EVT_DEV_ADDR_CONFLICT] = {
91		.size = sizeof(struct uwb_rc_evt_dev_addr_conflict),
92	},
93	[UWB_RC_EVT_DRP_AVAIL] = {
94		.size = sizeof(struct uwb_rc_evt_drp_avail)
95	},
96	[UWB_RC_EVT_DRP] = {
97		.size = sizeof(struct uwb_rc_evt_drp),
98		.offset = 1 + offsetof(struct uwb_rc_evt_drp, ie_length),
99	},
100	[UWB_RC_EVT_BP_SWITCH_STATUS] = {
101		.size = sizeof(struct uwb_rc_evt_bp_switch_status),
102	},
103	[UWB_RC_EVT_CMD_FRAME_RCV] = {
104		.size = sizeof(struct uwb_rc_evt_cmd_frame_rcv),
105		.offset = 1 + offsetof(struct uwb_rc_evt_cmd_frame_rcv, dataLength),
106	},
107	[UWB_RC_EVT_CHANNEL_CHANGE_IE_RCV] = {
108		.size = sizeof(struct uwb_rc_evt_channel_change_ie_rcv),
109		.offset = 1 + offsetof(struct uwb_rc_evt_channel_change_ie_rcv, wIELength),
110	},
111	[UWB_RC_CMD_CHANNEL_CHANGE] = {
112		.size = sizeof(struct uwb_rc_evt_confirm),
113	},
114	[UWB_RC_CMD_DEV_ADDR_MGMT] = {
115		.size = sizeof(struct uwb_rc_evt_dev_addr_mgmt) },
116	[UWB_RC_CMD_GET_IE] = {
117		.size = sizeof(struct uwb_rc_evt_get_ie),
118		.offset = 1 + offsetof(struct uwb_rc_evt_get_ie, wIELength),
119	},
120	[UWB_RC_CMD_RESET] = {
121		.size = sizeof(struct uwb_rc_evt_confirm),
122	},
123	[UWB_RC_CMD_SCAN] = {
124		.size = sizeof(struct uwb_rc_evt_confirm),
125	},
126	[UWB_RC_CMD_SET_BEACON_FILTER] = {
127		.size = sizeof(struct uwb_rc_evt_confirm),
128	},
129	[UWB_RC_CMD_SET_DRP_IE] = {
130		.size = sizeof(struct uwb_rc_evt_set_drp_ie),
131	},
132	[UWB_RC_CMD_SET_IE] = {
133		.size = sizeof(struct uwb_rc_evt_set_ie),
134	},
135	[UWB_RC_CMD_SET_NOTIFICATION_FILTER] = {
136		.size = sizeof(struct uwb_rc_evt_confirm),
137	},
138	[UWB_RC_CMD_SET_TX_POWER] = {
139		.size = sizeof(struct uwb_rc_evt_confirm),
140	},
141	[UWB_RC_CMD_SLEEP] = {
142		.size = sizeof(struct uwb_rc_evt_confirm),
143	},
144	[UWB_RC_CMD_START_BEACON] = {
145		.size = sizeof(struct uwb_rc_evt_confirm),
146	},
147	[UWB_RC_CMD_STOP_BEACON] = {
148		.size = sizeof(struct uwb_rc_evt_confirm),
149	},
150	[UWB_RC_CMD_BP_MERGE] = {
151		.size = sizeof(struct uwb_rc_evt_confirm),
152	},
153	[UWB_RC_CMD_SEND_COMMAND_FRAME] = {
154		.size = sizeof(struct uwb_rc_evt_confirm),
155	},
156	[UWB_RC_CMD_SET_ASIE_NOTIF] = {
157		.size = sizeof(struct uwb_rc_evt_confirm),
158	},
159};
160
161static
162struct uwb_est_entry uwb_est_01_00xx[] = {
163	[UWB_RC_DAA_ENERGY_DETECTED] = {
164		.size = sizeof(struct uwb_rc_evt_daa_energy_detected),
165	},
166	[UWB_RC_SET_DAA_ENERGY_MASK] = {
167		.size = sizeof(struct uwb_rc_evt_set_daa_energy_mask),
168	},
169	[UWB_RC_SET_NOTIFICATION_FILTER_EX] = {
170		.size = sizeof(struct uwb_rc_evt_set_notification_filter_ex),
171	},
172};
173
174/**
175 * Initialize the EST subsystem
176 *
177 * Register the standard tables also.
178 *
179 * FIXME: tag init
180 */
181int uwb_est_create(void)
182{
183	int result;
184
185	uwb_est_size = 2;
186	uwb_est_used = 0;
187	uwb_est = kcalloc(uwb_est_size, sizeof(uwb_est[0]), GFP_KERNEL);
188	if (uwb_est == NULL)
189		return -ENOMEM;
190
191	result = uwb_est_register(UWB_RC_CET_GENERAL, 0, 0xffff, 0xffff,
192				  uwb_est_00_00xx, ARRAY_SIZE(uwb_est_00_00xx));
193	if (result < 0)
194		goto out;
195	result = uwb_est_register(UWB_RC_CET_EX_TYPE_1, 0, 0xffff, 0xffff,
196				  uwb_est_01_00xx, ARRAY_SIZE(uwb_est_01_00xx));
197out:
198	return result;
199}
200
201
202/** Clean it up */
203void uwb_est_destroy(void)
204{
205	kfree(uwb_est);
206	uwb_est = NULL;
207	uwb_est_size = uwb_est_used = 0;
208}
209
210
211/**
212 * Double the capacity of the EST table
213 *
214 * @returns 0 if ok, < 0 errno no error.
215 */
216static
217int uwb_est_grow(void)
218{
219	size_t actual_size = uwb_est_size * sizeof(uwb_est[0]);
220	void *new = kmalloc(2 * actual_size, GFP_ATOMIC);
221	if (new == NULL)
222		return -ENOMEM;
223	memcpy(new, uwb_est, actual_size);
224	memset(new + actual_size, 0, actual_size);
225	kfree(uwb_est);
226	uwb_est = new;
227	uwb_est_size *= 2;
228	return 0;
229}
230
231
232/**
233 * Register an event size table
234 *
235 * Makes room for it if the table is full, and then inserts  it in the
236 * right position (entries are sorted by type, event_high, vendor and
237 * then product).
238 *
239 * @vendor:  vendor code for matching against the device (0x0000 and
240 *           0xffff mean any); use 0x0000 to force all to match without
241 *           checking possible vendor specific ones, 0xfffff to match
242 *           after checking vendor specific ones.
243 *
244 * @product: product code from that vendor; same matching rules, use
245 *           0x0000 for not allowing vendor specific matches, 0xffff
246 *           for allowing.
247 *
248 * This arragement just makes the tables sort differenty. Because the
249 * table is sorted by growing type-event_high-vendor-product, a zero
250 * vendor will match before than a 0x456a vendor, that will match
251 * before a 0xfffff vendor.
252 *
253 * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
254 */
255/* FIXME: add bus type to vendor/product code */
256int uwb_est_register(u8 type, u8 event_high, u16 vendor, u16 product,
257		     const struct uwb_est_entry *entry, size_t entries)
258{
259	unsigned long flags;
260	unsigned itr;
261	int result = 0;
262
263	write_lock_irqsave(&uwb_est_lock, flags);
264	if (uwb_est_used == uwb_est_size) {
265		result = uwb_est_grow();
266		if (result < 0)
267			goto out;
268	}
269	/* Find the right spot to insert it in */
270	for (itr = 0; itr < uwb_est_used; itr++)
271		if (uwb_est[itr].type_event_high < type
272		    && uwb_est[itr].vendor < vendor
273		    && uwb_est[itr].product < product)
274			break;
275
276	/* Shift others to make room for the new one? */
277	if (itr < uwb_est_used)
278		memmove(&uwb_est[itr+1], &uwb_est[itr], uwb_est_used - itr);
279	uwb_est[itr].type_event_high = type << 8 | event_high;
280	uwb_est[itr].vendor = vendor;
281	uwb_est[itr].product = product;
282	uwb_est[itr].entry = entry;
283	uwb_est[itr].entries = entries;
284	uwb_est_used++;
285out:
286	write_unlock_irqrestore(&uwb_est_lock, flags);
287	return result;
288}
289EXPORT_SYMBOL_GPL(uwb_est_register);
290
291
292/**
293 * Unregister an event size table
294 *
295 * This just removes the specified entry and moves the ones after it
296 * to fill in the gap. This is needed to keep the list sorted; no
297 * reallocation is done to reduce the size of the table.
298 *
299 * We unregister by all the data we used to register instead of by
300 * pointer to the @entry array because we might have used the same
301 * table for a bunch of IDs (for example).
302 *
303 * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
304 */
305int uwb_est_unregister(u8 type, u8 event_high, u16 vendor, u16 product,
306		       const struct uwb_est_entry *entry, size_t entries)
307{
308	unsigned long flags;
309	unsigned itr;
310	struct uwb_est est_cmp = {
311		.type_event_high = type << 8 | event_high,
312		.vendor = vendor,
313		.product = product,
314		.entry = entry,
315		.entries = entries
316	};
317	write_lock_irqsave(&uwb_est_lock, flags);
318	for (itr = 0; itr < uwb_est_used; itr++)
319		if (!memcmp(&uwb_est[itr], &est_cmp, sizeof(est_cmp)))
320			goto found;
321	write_unlock_irqrestore(&uwb_est_lock, flags);
322	return -ENOENT;
323
324found:
325	if (itr < uwb_est_used - 1)	/* Not last one? move ones above */
326		memmove(&uwb_est[itr], &uwb_est[itr+1], uwb_est_used - itr - 1);
327	uwb_est_used--;
328	write_unlock_irqrestore(&uwb_est_lock, flags);
329	return 0;
330}
331EXPORT_SYMBOL_GPL(uwb_est_unregister);
332
333
334/**
335 * Get the size of an event from a table
336 *
337 * @rceb: pointer to the buffer with the event
338 * @rceb_size: size of the area pointed to by @rceb in bytes.
339 * @returns: > 0      Size of the event
340 *	     -ENOSPC  An area big enough was not provided to look
341 *		      ahead into the event's guts and guess the size.
342 *	     -EINVAL  Unknown event code (wEvent).
343 *
344 * This will look at the received RCEB and guess what is the total
345 * size. For variable sized events, it will look further ahead into
346 * their length field to see how much data should be read.
347 *
348 * Note this size is *not* final--the neh (Notification/Event Handle)
349 * might specificy an extra size to add.
350 */
351static
352ssize_t uwb_est_get_size(struct uwb_rc *uwb_rc, struct uwb_est *est,
353			 u8 event_low, const struct uwb_rceb *rceb,
354			 size_t rceb_size)
355{
356	unsigned offset;
357	ssize_t size;
358	struct device *dev = &uwb_rc->uwb_dev.dev;
359	const struct uwb_est_entry *entry;
360
361	size = -ENOENT;
362	if (event_low >= est->entries) {	/* in range? */
363		dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u out of range\n",
364			est, est->type_event_high, est->vendor, est->product,
365			est->entries, event_low);
366		goto out;
367	}
368	size = -ENOENT;
369	entry = &est->entry[event_low];
370	if (entry->size == 0 && entry->offset == 0) {	/* unknown? */
371		dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: event %u unknown\n",
372			est, est->type_event_high, est->vendor,	est->product,
373			est->entries, event_low);
374		goto out;
375	}
376	offset = entry->offset;	/* extra fries with that? */
377	if (offset == 0)
378		size = entry->size;
379	else {
380		/* Ops, got an extra size field at 'offset'--read it */
381		const void *ptr = rceb;
382		size_t type_size = 0;
383		offset--;
384		size = -ENOSPC;			/* enough data for more? */
385		switch (entry->type) {
386		case UWB_EST_16:  type_size = sizeof(__le16); break;
387		case UWB_EST_8:   type_size = sizeof(u8);     break;
388		default: 	 BUG();
389		}
390		if (offset + type_size > rceb_size) {
391			dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
392				"not enough data to read extra size\n",
393				est, est->type_event_high, est->vendor,
394				est->product, est->entries);
395			goto out;
396		}
397		size = entry->size;
398		ptr += offset;
399		switch (entry->type) {
400		case UWB_EST_16:  size += le16_to_cpu(*(__le16 *)ptr); break;
401		case UWB_EST_8:   size += *(u8 *)ptr;                  break;
402		default: 	 BUG();
403		}
404	}
405out:
406	return size;
407}
408
409
410/**
411 * Guesses the size of a WA event
412 *
413 * @rceb: pointer to the buffer with the event
414 * @rceb_size: size of the area pointed to by @rceb in bytes.
415 * @returns: > 0      Size of the event
416 *	     -ENOSPC  An area big enough was not provided to look
417 *		      ahead into the event's guts and guess the size.
418 *	     -EINVAL  Unknown event code (wEvent).
419 *
420 * This will look at the received RCEB and guess what is the total
421 * size by checking all the tables registered with
422 * uwb_est_register(). For variable sized events, it will look further
423 * ahead into their length field to see how much data should be read.
424 *
425 * Note this size is *not* final--the neh (Notification/Event Handle)
426 * might specificy an extra size to add or replace.
427 */
428ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
429			  size_t rceb_size)
430{
431	/* FIXME: add vendor/product data */
432	ssize_t size;
433	struct device *dev = &rc->uwb_dev.dev;
434	unsigned long flags;
435	unsigned itr;
436	u16 type_event_high, event;
437
438	read_lock_irqsave(&uwb_est_lock, flags);
439	size = -ENOSPC;
440	if (rceb_size < sizeof(*rceb))
441		goto out;
442	event = le16_to_cpu(rceb->wEvent);
443	type_event_high = rceb->bEventType << 8 | (event & 0xff00) >> 8;
444	for (itr = 0; itr < uwb_est_used; itr++) {
445		if (uwb_est[itr].type_event_high != type_event_high)
446			continue;
447		size = uwb_est_get_size(rc, &uwb_est[itr],
448					event & 0x00ff, rceb, rceb_size);
449		/* try more tables that might handle the same type */
450		if (size != -ENOENT)
451			goto out;
452	}
453	dev_dbg(dev,
454		"event 0x%02x/%04x/%02x: no handlers available; RCEB %4ph\n",
455		(unsigned) rceb->bEventType,
456		(unsigned) le16_to_cpu(rceb->wEvent),
457		(unsigned) rceb->bEventContext,
458		rceb);
459	size = -ENOENT;
460out:
461	read_unlock_irqrestore(&uwb_est_lock, flags);
462	return size;
463}
464EXPORT_SYMBOL_GPL(uwb_est_find_size);
465