1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Core IEEE1394 transaction logic
4  *
5  * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
6  */
7 
8 #include <linux/bug.h>
9 #include <linux/completion.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/firewire.h>
13 #include <linux/firewire-constants.h>
14 #include <linux/fs.h>
15 #include <linux/init.h>
16 #include <linux/idr.h>
17 #include <linux/jiffies.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 #include <linux/rculist.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 #include <linux/string.h>
25 #include <linux/timer.h>
26 #include <linux/types.h>
27 #include <linux/workqueue.h>
28 
29 #include <asm/byteorder.h>
30 
31 #include "core.h"
32 
33 #define HEADER_PRI(pri)			((pri) << 0)
34 #define HEADER_TCODE(tcode)		((tcode) << 4)
35 #define HEADER_RETRY(retry)		((retry) << 8)
36 #define HEADER_TLABEL(tlabel)		((tlabel) << 10)
37 #define HEADER_DESTINATION(destination)	((destination) << 16)
38 #define HEADER_SOURCE(source)		((source) << 16)
39 #define HEADER_RCODE(rcode)		((rcode) << 12)
40 #define HEADER_OFFSET_HIGH(offset_high)	((offset_high) << 0)
41 #define HEADER_DATA_LENGTH(length)	((length) << 16)
42 #define HEADER_EXTENDED_TCODE(tcode)	((tcode) << 0)
43 
44 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
45 #define HEADER_GET_TLABEL(q)		(((q) >> 10) & 0x3f)
46 #define HEADER_GET_RCODE(q)		(((q) >> 12) & 0x0f)
47 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
48 #define HEADER_GET_SOURCE(q)		(((q) >> 16) & 0xffff)
49 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
50 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
51 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
52 
53 #define HEADER_DESTINATION_IS_BROADCAST(q) \
54 	(((q) & HEADER_DESTINATION(0x3f)) == HEADER_DESTINATION(0x3f))
55 
56 #define PHY_PACKET_CONFIG	0x0
57 #define PHY_PACKET_LINK_ON	0x1
58 #define PHY_PACKET_SELF_ID	0x2
59 
60 #define PHY_CONFIG_GAP_COUNT(gap_count)	(((gap_count) << 16) | (1 << 22))
61 #define PHY_CONFIG_ROOT_ID(node_id)	((((node_id) & 0x3f) << 24) | (1 << 23))
62 #define PHY_IDENTIFIER(id)		((id) << 30)
63 
64 /* returns 0 if the split timeout handler is already running */
65 static int try_cancel_split_timeout(struct fw_transaction *t)
66 {
67 	if (t->is_split_transaction)
68 		return del_timer(&t->split_timeout_timer);
69 	else
70 		return 1;
71 }
72 
73 static int close_transaction(struct fw_transaction *transaction,
74 			     struct fw_card *card, int rcode)
75 {
76 	struct fw_transaction *t = NULL, *iter;
77 	unsigned long flags;
78 
79 	spin_lock_irqsave(&card->lock, flags);
80 	list_for_each_entry(iter, &card->transaction_list, link) {
81 		if (iter == transaction) {
82 			if (!try_cancel_split_timeout(iter)) {
83 				spin_unlock_irqrestore(&card->lock, flags);
84 				goto timed_out;
85 			}
86 			list_del_init(&iter->link);
87 			card->tlabel_mask &= ~(1ULL << iter->tlabel);
88 			t = iter;
89 			break;
90 		}
91 	}
92 	spin_unlock_irqrestore(&card->lock, flags);
93 
94 	if (t) {
95 		t->callback(card, rcode, NULL, 0, t->callback_data);
96 		return 0;
97 	}
98 
99  timed_out:
100 	return -ENOENT;
101 }
102 
103 /*
104  * Only valid for transactions that are potentially pending (ie have
105  * been sent).
106  */
107 int fw_cancel_transaction(struct fw_card *card,
108 			  struct fw_transaction *transaction)
109 {
110 	/*
111 	 * Cancel the packet transmission if it's still queued.  That
112 	 * will call the packet transmission callback which cancels
113 	 * the transaction.
114 	 */
115 
116 	if (card->driver->cancel_packet(card, &transaction->packet) == 0)
117 		return 0;
118 
119 	/*
120 	 * If the request packet has already been sent, we need to see
121 	 * if the transaction is still pending and remove it in that case.
122 	 */
123 
124 	return close_transaction(transaction, card, RCODE_CANCELLED);
125 }
126 EXPORT_SYMBOL(fw_cancel_transaction);
127 
128 static void split_transaction_timeout_callback(struct timer_list *timer)
129 {
130 	struct fw_transaction *t = from_timer(t, timer, split_timeout_timer);
131 	struct fw_card *card = t->card;
132 	unsigned long flags;
133 
134 	spin_lock_irqsave(&card->lock, flags);
135 	if (list_empty(&t->link)) {
136 		spin_unlock_irqrestore(&card->lock, flags);
137 		return;
138 	}
139 	list_del(&t->link);
140 	card->tlabel_mask &= ~(1ULL << t->tlabel);
141 	spin_unlock_irqrestore(&card->lock, flags);
142 
143 	t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
144 }
145 
146 static void start_split_transaction_timeout(struct fw_transaction *t,
147 					    struct fw_card *card)
148 {
149 	unsigned long flags;
150 
151 	spin_lock_irqsave(&card->lock, flags);
152 
153 	if (list_empty(&t->link) || WARN_ON(t->is_split_transaction)) {
154 		spin_unlock_irqrestore(&card->lock, flags);
155 		return;
156 	}
157 
158 	t->is_split_transaction = true;
159 	mod_timer(&t->split_timeout_timer,
160 		  jiffies + card->split_timeout_jiffies);
161 
162 	spin_unlock_irqrestore(&card->lock, flags);
163 }
164 
165 static void transmit_complete_callback(struct fw_packet *packet,
166 				       struct fw_card *card, int status)
167 {
168 	struct fw_transaction *t =
169 	    container_of(packet, struct fw_transaction, packet);
170 
171 	switch (status) {
172 	case ACK_COMPLETE:
173 		close_transaction(t, card, RCODE_COMPLETE);
174 		break;
175 	case ACK_PENDING:
176 		start_split_transaction_timeout(t, card);
177 		break;
178 	case ACK_BUSY_X:
179 	case ACK_BUSY_A:
180 	case ACK_BUSY_B:
181 		close_transaction(t, card, RCODE_BUSY);
182 		break;
183 	case ACK_DATA_ERROR:
184 		close_transaction(t, card, RCODE_DATA_ERROR);
185 		break;
186 	case ACK_TYPE_ERROR:
187 		close_transaction(t, card, RCODE_TYPE_ERROR);
188 		break;
189 	default:
190 		/*
191 		 * In this case the ack is really a juju specific
192 		 * rcode, so just forward that to the callback.
193 		 */
194 		close_transaction(t, card, status);
195 		break;
196 	}
197 }
198 
199 static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
200 		int destination_id, int source_id, int generation, int speed,
201 		unsigned long long offset, void *payload, size_t length)
202 {
203 	int ext_tcode;
204 
205 	if (tcode == TCODE_STREAM_DATA) {
206 		packet->header[0] =
207 			HEADER_DATA_LENGTH(length) |
208 			destination_id |
209 			HEADER_TCODE(TCODE_STREAM_DATA);
210 		packet->header_length = 4;
211 		packet->payload = payload;
212 		packet->payload_length = length;
213 
214 		goto common;
215 	}
216 
217 	if (tcode > 0x10) {
218 		ext_tcode = tcode & ~0x10;
219 		tcode = TCODE_LOCK_REQUEST;
220 	} else
221 		ext_tcode = 0;
222 
223 	packet->header[0] =
224 		HEADER_RETRY(RETRY_X) |
225 		HEADER_TLABEL(tlabel) |
226 		HEADER_TCODE(tcode) |
227 		HEADER_DESTINATION(destination_id);
228 	packet->header[1] =
229 		HEADER_OFFSET_HIGH(offset >> 32) | HEADER_SOURCE(source_id);
230 	packet->header[2] =
231 		offset;
232 
233 	switch (tcode) {
234 	case TCODE_WRITE_QUADLET_REQUEST:
235 		packet->header[3] = *(u32 *)payload;
236 		packet->header_length = 16;
237 		packet->payload_length = 0;
238 		break;
239 
240 	case TCODE_LOCK_REQUEST:
241 	case TCODE_WRITE_BLOCK_REQUEST:
242 		packet->header[3] =
243 			HEADER_DATA_LENGTH(length) |
244 			HEADER_EXTENDED_TCODE(ext_tcode);
245 		packet->header_length = 16;
246 		packet->payload = payload;
247 		packet->payload_length = length;
248 		break;
249 
250 	case TCODE_READ_QUADLET_REQUEST:
251 		packet->header_length = 12;
252 		packet->payload_length = 0;
253 		break;
254 
255 	case TCODE_READ_BLOCK_REQUEST:
256 		packet->header[3] =
257 			HEADER_DATA_LENGTH(length) |
258 			HEADER_EXTENDED_TCODE(ext_tcode);
259 		packet->header_length = 16;
260 		packet->payload_length = 0;
261 		break;
262 
263 	default:
264 		WARN(1, "wrong tcode %d\n", tcode);
265 	}
266  common:
267 	packet->speed = speed;
268 	packet->generation = generation;
269 	packet->ack = 0;
270 	packet->payload_mapped = false;
271 }
272 
273 static int allocate_tlabel(struct fw_card *card)
274 {
275 	int tlabel;
276 
277 	tlabel = card->current_tlabel;
278 	while (card->tlabel_mask & (1ULL << tlabel)) {
279 		tlabel = (tlabel + 1) & 0x3f;
280 		if (tlabel == card->current_tlabel)
281 			return -EBUSY;
282 	}
283 
284 	card->current_tlabel = (tlabel + 1) & 0x3f;
285 	card->tlabel_mask |= 1ULL << tlabel;
286 
287 	return tlabel;
288 }
289 
290 /**
291  * fw_send_request() - submit a request packet for transmission
292  * @card:		interface to send the request at
293  * @t:			transaction instance to which the request belongs
294  * @tcode:		transaction code
295  * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
296  * @generation:		bus generation in which request and response are valid
297  * @speed:		transmission speed
298  * @offset:		48bit wide offset into destination's address space
299  * @payload:		data payload for the request subaction
300  * @length:		length of the payload, in bytes
301  * @callback:		function to be called when the transaction is completed
302  * @callback_data:	data to be passed to the transaction completion callback
303  *
304  * Submit a request packet into the asynchronous request transmission queue.
305  * Can be called from atomic context.  If you prefer a blocking API, use
306  * fw_run_transaction() in a context that can sleep.
307  *
308  * In case of lock requests, specify one of the firewire-core specific %TCODE_
309  * constants instead of %TCODE_LOCK_REQUEST in @tcode.
310  *
311  * Make sure that the value in @destination_id is not older than the one in
312  * @generation.  Otherwise the request is in danger to be sent to a wrong node.
313  *
314  * In case of asynchronous stream packets i.e. %TCODE_STREAM_DATA, the caller
315  * needs to synthesize @destination_id with fw_stream_packet_destination_id().
316  * It will contain tag, channel, and sy data instead of a node ID then.
317  *
318  * The payload buffer at @data is going to be DMA-mapped except in case of
319  * @length <= 8 or of local (loopback) requests.  Hence make sure that the
320  * buffer complies with the restrictions of the streaming DMA mapping API.
321  * @payload must not be freed before the @callback is called.
322  *
323  * In case of request types without payload, @data is NULL and @length is 0.
324  *
325  * After the transaction is completed successfully or unsuccessfully, the
326  * @callback will be called.  Among its parameters is the response code which
327  * is either one of the rcodes per IEEE 1394 or, in case of internal errors,
328  * the firewire-core specific %RCODE_SEND_ERROR.  The other firewire-core
329  * specific rcodes (%RCODE_CANCELLED, %RCODE_BUSY, %RCODE_GENERATION,
330  * %RCODE_NO_ACK) denote transaction timeout, busy responder, stale request
331  * generation, or missing ACK respectively.
332  *
333  * Note some timing corner cases:  fw_send_request() may complete much earlier
334  * than when the request packet actually hits the wire.  On the other hand,
335  * transaction completion and hence execution of @callback may happen even
336  * before fw_send_request() returns.
337  */
338 void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
339 		     int destination_id, int generation, int speed,
340 		     unsigned long long offset, void *payload, size_t length,
341 		     fw_transaction_callback_t callback, void *callback_data)
342 {
343 	unsigned long flags;
344 	int tlabel;
345 
346 	/*
347 	 * Allocate tlabel from the bitmap and put the transaction on
348 	 * the list while holding the card spinlock.
349 	 */
350 
351 	spin_lock_irqsave(&card->lock, flags);
352 
353 	tlabel = allocate_tlabel(card);
354 	if (tlabel < 0) {
355 		spin_unlock_irqrestore(&card->lock, flags);
356 		callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
357 		return;
358 	}
359 
360 	t->node_id = destination_id;
361 	t->tlabel = tlabel;
362 	t->card = card;
363 	t->is_split_transaction = false;
364 	timer_setup(&t->split_timeout_timer,
365 		    split_transaction_timeout_callback, 0);
366 	t->callback = callback;
367 	t->callback_data = callback_data;
368 
369 	fw_fill_request(&t->packet, tcode, t->tlabel,
370 			destination_id, card->node_id, generation,
371 			speed, offset, payload, length);
372 	t->packet.callback = transmit_complete_callback;
373 
374 	list_add_tail(&t->link, &card->transaction_list);
375 
376 	spin_unlock_irqrestore(&card->lock, flags);
377 
378 	card->driver->send_request(card, &t->packet);
379 }
380 EXPORT_SYMBOL(fw_send_request);
381 
382 struct transaction_callback_data {
383 	struct completion done;
384 	void *payload;
385 	int rcode;
386 };
387 
388 static void transaction_callback(struct fw_card *card, int rcode,
389 				 void *payload, size_t length, void *data)
390 {
391 	struct transaction_callback_data *d = data;
392 
393 	if (rcode == RCODE_COMPLETE)
394 		memcpy(d->payload, payload, length);
395 	d->rcode = rcode;
396 	complete(&d->done);
397 }
398 
399 /**
400  * fw_run_transaction() - send request and sleep until transaction is completed
401  * @card:		card interface for this request
402  * @tcode:		transaction code
403  * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
404  * @generation:		bus generation in which request and response are valid
405  * @speed:		transmission speed
406  * @offset:		48bit wide offset into destination's address space
407  * @payload:		data payload for the request subaction
408  * @length:		length of the payload, in bytes
409  *
410  * Returns the RCODE.  See fw_send_request() for parameter documentation.
411  * Unlike fw_send_request(), @data points to the payload of the request or/and
412  * to the payload of the response.  DMA mapping restrictions apply to outbound
413  * request payloads of >= 8 bytes but not to inbound response payloads.
414  */
415 int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
416 		       int generation, int speed, unsigned long long offset,
417 		       void *payload, size_t length)
418 {
419 	struct transaction_callback_data d;
420 	struct fw_transaction t;
421 
422 	timer_setup_on_stack(&t.split_timeout_timer, NULL, 0);
423 	init_completion(&d.done);
424 	d.payload = payload;
425 	fw_send_request(card, &t, tcode, destination_id, generation, speed,
426 			offset, payload, length, transaction_callback, &d);
427 	wait_for_completion(&d.done);
428 	destroy_timer_on_stack(&t.split_timeout_timer);
429 
430 	return d.rcode;
431 }
432 EXPORT_SYMBOL(fw_run_transaction);
433 
434 static DEFINE_MUTEX(phy_config_mutex);
435 static DECLARE_COMPLETION(phy_config_done);
436 
437 static void transmit_phy_packet_callback(struct fw_packet *packet,
438 					 struct fw_card *card, int status)
439 {
440 	complete(&phy_config_done);
441 }
442 
443 static struct fw_packet phy_config_packet = {
444 	.header_length	= 12,
445 	.header[0]	= TCODE_LINK_INTERNAL << 4,
446 	.payload_length	= 0,
447 	.speed		= SCODE_100,
448 	.callback	= transmit_phy_packet_callback,
449 };
450 
451 void fw_send_phy_config(struct fw_card *card,
452 			int node_id, int generation, int gap_count)
453 {
454 	long timeout = DIV_ROUND_UP(HZ, 10);
455 	u32 data = PHY_IDENTIFIER(PHY_PACKET_CONFIG);
456 
457 	if (node_id != FW_PHY_CONFIG_NO_NODE_ID)
458 		data |= PHY_CONFIG_ROOT_ID(node_id);
459 
460 	if (gap_count == FW_PHY_CONFIG_CURRENT_GAP_COUNT) {
461 		gap_count = card->driver->read_phy_reg(card, 1);
462 		if (gap_count < 0)
463 			return;
464 
465 		gap_count &= 63;
466 		if (gap_count == 63)
467 			return;
468 	}
469 	data |= PHY_CONFIG_GAP_COUNT(gap_count);
470 
471 	mutex_lock(&phy_config_mutex);
472 
473 	phy_config_packet.header[1] = data;
474 	phy_config_packet.header[2] = ~data;
475 	phy_config_packet.generation = generation;
476 	reinit_completion(&phy_config_done);
477 
478 	card->driver->send_request(card, &phy_config_packet);
479 	wait_for_completion_timeout(&phy_config_done, timeout);
480 
481 	mutex_unlock(&phy_config_mutex);
482 }
483 
484 static struct fw_address_handler *lookup_overlapping_address_handler(
485 	struct list_head *list, unsigned long long offset, size_t length)
486 {
487 	struct fw_address_handler *handler;
488 
489 	list_for_each_entry_rcu(handler, list, link) {
490 		if (handler->offset < offset + length &&
491 		    offset < handler->offset + handler->length)
492 			return handler;
493 	}
494 
495 	return NULL;
496 }
497 
498 static bool is_enclosing_handler(struct fw_address_handler *handler,
499 				 unsigned long long offset, size_t length)
500 {
501 	return handler->offset <= offset &&
502 		offset + length <= handler->offset + handler->length;
503 }
504 
505 static struct fw_address_handler *lookup_enclosing_address_handler(
506 	struct list_head *list, unsigned long long offset, size_t length)
507 {
508 	struct fw_address_handler *handler;
509 
510 	list_for_each_entry_rcu(handler, list, link) {
511 		if (is_enclosing_handler(handler, offset, length))
512 			return handler;
513 	}
514 
515 	return NULL;
516 }
517 
518 static DEFINE_SPINLOCK(address_handler_list_lock);
519 static LIST_HEAD(address_handler_list);
520 
521 const struct fw_address_region fw_high_memory_region =
522 	{ .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
523 EXPORT_SYMBOL(fw_high_memory_region);
524 
525 static const struct fw_address_region low_memory_region =
526 	{ .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
527 
528 #if 0
529 const struct fw_address_region fw_private_region =
530 	{ .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
531 const struct fw_address_region fw_csr_region =
532 	{ .start = CSR_REGISTER_BASE,
533 	  .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM_END,  };
534 const struct fw_address_region fw_unit_space_region =
535 	{ .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
536 #endif  /*  0  */
537 
538 /**
539  * fw_core_add_address_handler() - register for incoming requests
540  * @handler:	callback
541  * @region:	region in the IEEE 1212 node space address range
542  *
543  * region->start, ->end, and handler->length have to be quadlet-aligned.
544  *
545  * When a request is received that falls within the specified address range,
546  * the specified callback is invoked.  The parameters passed to the callback
547  * give the details of the particular request.
548  *
549  * To be called in process context.
550  * Return value:  0 on success, non-zero otherwise.
551  *
552  * The start offset of the handler's address region is determined by
553  * fw_core_add_address_handler() and is returned in handler->offset.
554  *
555  * Address allocations are exclusive, except for the FCP registers.
556  */
557 int fw_core_add_address_handler(struct fw_address_handler *handler,
558 				const struct fw_address_region *region)
559 {
560 	struct fw_address_handler *other;
561 	int ret = -EBUSY;
562 
563 	if (region->start & 0xffff000000000003ULL ||
564 	    region->start >= region->end ||
565 	    region->end   > 0x0001000000000000ULL ||
566 	    handler->length & 3 ||
567 	    handler->length == 0)
568 		return -EINVAL;
569 
570 	spin_lock(&address_handler_list_lock);
571 
572 	handler->offset = region->start;
573 	while (handler->offset + handler->length <= region->end) {
574 		if (is_in_fcp_region(handler->offset, handler->length))
575 			other = NULL;
576 		else
577 			other = lookup_overlapping_address_handler
578 					(&address_handler_list,
579 					 handler->offset, handler->length);
580 		if (other != NULL) {
581 			handler->offset += other->length;
582 		} else {
583 			list_add_tail_rcu(&handler->link, &address_handler_list);
584 			ret = 0;
585 			break;
586 		}
587 	}
588 
589 	spin_unlock(&address_handler_list_lock);
590 
591 	return ret;
592 }
593 EXPORT_SYMBOL(fw_core_add_address_handler);
594 
595 /**
596  * fw_core_remove_address_handler() - unregister an address handler
597  * @handler: callback
598  *
599  * To be called in process context.
600  *
601  * When fw_core_remove_address_handler() returns, @handler->callback() is
602  * guaranteed to not run on any CPU anymore.
603  */
604 void fw_core_remove_address_handler(struct fw_address_handler *handler)
605 {
606 	spin_lock(&address_handler_list_lock);
607 	list_del_rcu(&handler->link);
608 	spin_unlock(&address_handler_list_lock);
609 	synchronize_rcu();
610 }
611 EXPORT_SYMBOL(fw_core_remove_address_handler);
612 
613 struct fw_request {
614 	struct kref kref;
615 	struct fw_packet response;
616 	u32 request_header[4];
617 	int ack;
618 	u32 timestamp;
619 	u32 length;
620 	u32 data[];
621 };
622 
623 void fw_request_get(struct fw_request *request)
624 {
625 	kref_get(&request->kref);
626 }
627 
628 static void release_request(struct kref *kref)
629 {
630 	struct fw_request *request = container_of(kref, struct fw_request, kref);
631 
632 	kfree(request);
633 }
634 
635 void fw_request_put(struct fw_request *request)
636 {
637 	kref_put(&request->kref, release_request);
638 }
639 
640 static void free_response_callback(struct fw_packet *packet,
641 				   struct fw_card *card, int status)
642 {
643 	struct fw_request *request = container_of(packet, struct fw_request, response);
644 
645 	// Decrease the reference count since not at in-flight.
646 	fw_request_put(request);
647 
648 	// Decrease the reference count to release the object.
649 	fw_request_put(request);
650 }
651 
652 int fw_get_response_length(struct fw_request *r)
653 {
654 	int tcode, ext_tcode, data_length;
655 
656 	tcode = HEADER_GET_TCODE(r->request_header[0]);
657 
658 	switch (tcode) {
659 	case TCODE_WRITE_QUADLET_REQUEST:
660 	case TCODE_WRITE_BLOCK_REQUEST:
661 		return 0;
662 
663 	case TCODE_READ_QUADLET_REQUEST:
664 		return 4;
665 
666 	case TCODE_READ_BLOCK_REQUEST:
667 		data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
668 		return data_length;
669 
670 	case TCODE_LOCK_REQUEST:
671 		ext_tcode = HEADER_GET_EXTENDED_TCODE(r->request_header[3]);
672 		data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
673 		switch (ext_tcode) {
674 		case EXTCODE_FETCH_ADD:
675 		case EXTCODE_LITTLE_ADD:
676 			return data_length;
677 		default:
678 			return data_length / 2;
679 		}
680 
681 	default:
682 		WARN(1, "wrong tcode %d\n", tcode);
683 		return 0;
684 	}
685 }
686 
687 void fw_fill_response(struct fw_packet *response, u32 *request_header,
688 		      int rcode, void *payload, size_t length)
689 {
690 	int tcode, tlabel, extended_tcode, source, destination;
691 
692 	tcode          = HEADER_GET_TCODE(request_header[0]);
693 	tlabel         = HEADER_GET_TLABEL(request_header[0]);
694 	source         = HEADER_GET_DESTINATION(request_header[0]);
695 	destination    = HEADER_GET_SOURCE(request_header[1]);
696 	extended_tcode = HEADER_GET_EXTENDED_TCODE(request_header[3]);
697 
698 	response->header[0] =
699 		HEADER_RETRY(RETRY_1) |
700 		HEADER_TLABEL(tlabel) |
701 		HEADER_DESTINATION(destination);
702 	response->header[1] =
703 		HEADER_SOURCE(source) |
704 		HEADER_RCODE(rcode);
705 	response->header[2] = 0;
706 
707 	switch (tcode) {
708 	case TCODE_WRITE_QUADLET_REQUEST:
709 	case TCODE_WRITE_BLOCK_REQUEST:
710 		response->header[0] |= HEADER_TCODE(TCODE_WRITE_RESPONSE);
711 		response->header_length = 12;
712 		response->payload_length = 0;
713 		break;
714 
715 	case TCODE_READ_QUADLET_REQUEST:
716 		response->header[0] |=
717 			HEADER_TCODE(TCODE_READ_QUADLET_RESPONSE);
718 		if (payload != NULL)
719 			response->header[3] = *(u32 *)payload;
720 		else
721 			response->header[3] = 0;
722 		response->header_length = 16;
723 		response->payload_length = 0;
724 		break;
725 
726 	case TCODE_READ_BLOCK_REQUEST:
727 	case TCODE_LOCK_REQUEST:
728 		response->header[0] |= HEADER_TCODE(tcode + 2);
729 		response->header[3] =
730 			HEADER_DATA_LENGTH(length) |
731 			HEADER_EXTENDED_TCODE(extended_tcode);
732 		response->header_length = 16;
733 		response->payload = payload;
734 		response->payload_length = length;
735 		break;
736 
737 	default:
738 		WARN(1, "wrong tcode %d\n", tcode);
739 	}
740 
741 	response->payload_mapped = false;
742 }
743 EXPORT_SYMBOL(fw_fill_response);
744 
745 static u32 compute_split_timeout_timestamp(struct fw_card *card,
746 					   u32 request_timestamp)
747 {
748 	unsigned int cycles;
749 	u32 timestamp;
750 
751 	cycles = card->split_timeout_cycles;
752 	cycles += request_timestamp & 0x1fff;
753 
754 	timestamp = request_timestamp & ~0x1fff;
755 	timestamp += (cycles / 8000) << 13;
756 	timestamp |= cycles % 8000;
757 
758 	return timestamp;
759 }
760 
761 static struct fw_request *allocate_request(struct fw_card *card,
762 					   struct fw_packet *p)
763 {
764 	struct fw_request *request;
765 	u32 *data, length;
766 	int request_tcode;
767 
768 	request_tcode = HEADER_GET_TCODE(p->header[0]);
769 	switch (request_tcode) {
770 	case TCODE_WRITE_QUADLET_REQUEST:
771 		data = &p->header[3];
772 		length = 4;
773 		break;
774 
775 	case TCODE_WRITE_BLOCK_REQUEST:
776 	case TCODE_LOCK_REQUEST:
777 		data = p->payload;
778 		length = HEADER_GET_DATA_LENGTH(p->header[3]);
779 		break;
780 
781 	case TCODE_READ_QUADLET_REQUEST:
782 		data = NULL;
783 		length = 4;
784 		break;
785 
786 	case TCODE_READ_BLOCK_REQUEST:
787 		data = NULL;
788 		length = HEADER_GET_DATA_LENGTH(p->header[3]);
789 		break;
790 
791 	default:
792 		fw_notice(card, "ERROR - corrupt request received - %08x %08x %08x\n",
793 			 p->header[0], p->header[1], p->header[2]);
794 		return NULL;
795 	}
796 
797 	request = kmalloc(sizeof(*request) + length, GFP_ATOMIC);
798 	if (request == NULL)
799 		return NULL;
800 	kref_init(&request->kref);
801 
802 	request->response.speed = p->speed;
803 	request->response.timestamp =
804 			compute_split_timeout_timestamp(card, p->timestamp);
805 	request->response.generation = p->generation;
806 	request->response.ack = 0;
807 	request->response.callback = free_response_callback;
808 	request->ack = p->ack;
809 	request->timestamp = p->timestamp;
810 	request->length = length;
811 	if (data)
812 		memcpy(request->data, data, length);
813 
814 	memcpy(request->request_header, p->header, sizeof(p->header));
815 
816 	return request;
817 }
818 
819 /**
820  * fw_send_response: - send response packet for asynchronous transaction.
821  * @card:	interface to send the response at.
822  * @request:	firewire request data for the transaction.
823  * @rcode:	response code to send.
824  *
825  * Submit a response packet into the asynchronous response transmission queue. The @request
826  * is going to be released when the transmission successfully finishes later.
827  */
828 void fw_send_response(struct fw_card *card,
829 		      struct fw_request *request, int rcode)
830 {
831 	/* unified transaction or broadcast transaction: don't respond */
832 	if (request->ack != ACK_PENDING ||
833 	    HEADER_DESTINATION_IS_BROADCAST(request->request_header[0])) {
834 		fw_request_put(request);
835 		return;
836 	}
837 
838 	if (rcode == RCODE_COMPLETE)
839 		fw_fill_response(&request->response, request->request_header,
840 				 rcode, request->data,
841 				 fw_get_response_length(request));
842 	else
843 		fw_fill_response(&request->response, request->request_header,
844 				 rcode, NULL, 0);
845 
846 	// Increase the reference count so that the object is kept during in-flight.
847 	fw_request_get(request);
848 
849 	card->driver->send_response(card, &request->response);
850 }
851 EXPORT_SYMBOL(fw_send_response);
852 
853 /**
854  * fw_get_request_speed() - returns speed at which the @request was received
855  * @request: firewire request data
856  */
857 int fw_get_request_speed(struct fw_request *request)
858 {
859 	return request->response.speed;
860 }
861 EXPORT_SYMBOL(fw_get_request_speed);
862 
863 /**
864  * fw_request_get_timestamp: Get timestamp of the request.
865  * @request: The opaque pointer to request structure.
866  *
867  * Get timestamp when 1394 OHCI controller receives the asynchronous request subaction. The
868  * timestamp consists of the low order 3 bits of second field and the full 13 bits of count
869  * field of isochronous cycle time register.
870  *
871  * Returns: timestamp of the request.
872  */
873 u32 fw_request_get_timestamp(const struct fw_request *request)
874 {
875 	return request->timestamp;
876 }
877 EXPORT_SYMBOL_GPL(fw_request_get_timestamp);
878 
879 static void handle_exclusive_region_request(struct fw_card *card,
880 					    struct fw_packet *p,
881 					    struct fw_request *request,
882 					    unsigned long long offset)
883 {
884 	struct fw_address_handler *handler;
885 	int tcode, destination, source;
886 
887 	destination = HEADER_GET_DESTINATION(p->header[0]);
888 	source      = HEADER_GET_SOURCE(p->header[1]);
889 	tcode       = HEADER_GET_TCODE(p->header[0]);
890 	if (tcode == TCODE_LOCK_REQUEST)
891 		tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);
892 
893 	rcu_read_lock();
894 	handler = lookup_enclosing_address_handler(&address_handler_list,
895 						   offset, request->length);
896 	if (handler)
897 		handler->address_callback(card, request,
898 					  tcode, destination, source,
899 					  p->generation, offset,
900 					  request->data, request->length,
901 					  handler->callback_data);
902 	rcu_read_unlock();
903 
904 	if (!handler)
905 		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
906 }
907 
908 static void handle_fcp_region_request(struct fw_card *card,
909 				      struct fw_packet *p,
910 				      struct fw_request *request,
911 				      unsigned long long offset)
912 {
913 	struct fw_address_handler *handler;
914 	int tcode, destination, source;
915 
916 	if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
917 	     offset != (CSR_REGISTER_BASE | CSR_FCP_RESPONSE)) ||
918 	    request->length > 0x200) {
919 		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
920 
921 		return;
922 	}
923 
924 	tcode       = HEADER_GET_TCODE(p->header[0]);
925 	destination = HEADER_GET_DESTINATION(p->header[0]);
926 	source      = HEADER_GET_SOURCE(p->header[1]);
927 
928 	if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
929 	    tcode != TCODE_WRITE_BLOCK_REQUEST) {
930 		fw_send_response(card, request, RCODE_TYPE_ERROR);
931 
932 		return;
933 	}
934 
935 	rcu_read_lock();
936 	list_for_each_entry_rcu(handler, &address_handler_list, link) {
937 		if (is_enclosing_handler(handler, offset, request->length))
938 			handler->address_callback(card, request, tcode,
939 						  destination, source,
940 						  p->generation, offset,
941 						  request->data,
942 						  request->length,
943 						  handler->callback_data);
944 	}
945 	rcu_read_unlock();
946 
947 	fw_send_response(card, request, RCODE_COMPLETE);
948 }
949 
950 void fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
951 {
952 	struct fw_request *request;
953 	unsigned long long offset;
954 
955 	if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
956 		return;
957 
958 	if (TCODE_IS_LINK_INTERNAL(HEADER_GET_TCODE(p->header[0]))) {
959 		fw_cdev_handle_phy_packet(card, p);
960 		return;
961 	}
962 
963 	request = allocate_request(card, p);
964 	if (request == NULL) {
965 		/* FIXME: send statically allocated busy packet. */
966 		return;
967 	}
968 
969 	offset = ((u64)HEADER_GET_OFFSET_HIGH(p->header[1]) << 32) |
970 		p->header[2];
971 
972 	if (!is_in_fcp_region(offset, request->length))
973 		handle_exclusive_region_request(card, p, request, offset);
974 	else
975 		handle_fcp_region_request(card, p, request, offset);
976 
977 }
978 EXPORT_SYMBOL(fw_core_handle_request);
979 
980 void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
981 {
982 	struct fw_transaction *t = NULL, *iter;
983 	unsigned long flags;
984 	u32 *data;
985 	size_t data_length;
986 	int tcode, tlabel, source, rcode;
987 
988 	tcode	= HEADER_GET_TCODE(p->header[0]);
989 	tlabel	= HEADER_GET_TLABEL(p->header[0]);
990 	source	= HEADER_GET_SOURCE(p->header[1]);
991 	rcode	= HEADER_GET_RCODE(p->header[1]);
992 
993 	spin_lock_irqsave(&card->lock, flags);
994 	list_for_each_entry(iter, &card->transaction_list, link) {
995 		if (iter->node_id == source && iter->tlabel == tlabel) {
996 			if (!try_cancel_split_timeout(iter)) {
997 				spin_unlock_irqrestore(&card->lock, flags);
998 				goto timed_out;
999 			}
1000 			list_del_init(&iter->link);
1001 			card->tlabel_mask &= ~(1ULL << iter->tlabel);
1002 			t = iter;
1003 			break;
1004 		}
1005 	}
1006 	spin_unlock_irqrestore(&card->lock, flags);
1007 
1008 	if (!t) {
1009  timed_out:
1010 		fw_notice(card, "unsolicited response (source %x, tlabel %x)\n",
1011 			  source, tlabel);
1012 		return;
1013 	}
1014 
1015 	/*
1016 	 * FIXME: sanity check packet, is length correct, does tcodes
1017 	 * and addresses match.
1018 	 */
1019 
1020 	switch (tcode) {
1021 	case TCODE_READ_QUADLET_RESPONSE:
1022 		data = (u32 *) &p->header[3];
1023 		data_length = 4;
1024 		break;
1025 
1026 	case TCODE_WRITE_RESPONSE:
1027 		data = NULL;
1028 		data_length = 0;
1029 		break;
1030 
1031 	case TCODE_READ_BLOCK_RESPONSE:
1032 	case TCODE_LOCK_RESPONSE:
1033 		data = p->payload;
1034 		data_length = HEADER_GET_DATA_LENGTH(p->header[3]);
1035 		break;
1036 
1037 	default:
1038 		/* Should never happen, this is just to shut up gcc. */
1039 		data = NULL;
1040 		data_length = 0;
1041 		break;
1042 	}
1043 
1044 	/*
1045 	 * The response handler may be executed while the request handler
1046 	 * is still pending.  Cancel the request handler.
1047 	 */
1048 	card->driver->cancel_packet(card, &t->packet);
1049 
1050 	t->callback(card, rcode, data, data_length, t->callback_data);
1051 }
1052 EXPORT_SYMBOL(fw_core_handle_response);
1053 
1054 /**
1055  * fw_rcode_string - convert a firewire result code to an error description
1056  * @rcode: the result code
1057  */
1058 const char *fw_rcode_string(int rcode)
1059 {
1060 	static const char *const names[] = {
1061 		[RCODE_COMPLETE]       = "no error",
1062 		[RCODE_CONFLICT_ERROR] = "conflict error",
1063 		[RCODE_DATA_ERROR]     = "data error",
1064 		[RCODE_TYPE_ERROR]     = "type error",
1065 		[RCODE_ADDRESS_ERROR]  = "address error",
1066 		[RCODE_SEND_ERROR]     = "send error",
1067 		[RCODE_CANCELLED]      = "timeout",
1068 		[RCODE_BUSY]           = "busy",
1069 		[RCODE_GENERATION]     = "bus reset",
1070 		[RCODE_NO_ACK]         = "no ack",
1071 	};
1072 
1073 	if ((unsigned int)rcode < ARRAY_SIZE(names) && names[rcode])
1074 		return names[rcode];
1075 	else
1076 		return "unknown";
1077 }
1078 EXPORT_SYMBOL(fw_rcode_string);
1079 
1080 static const struct fw_address_region topology_map_region =
1081 	{ .start = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP,
1082 	  .end   = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP_END, };
1083 
1084 static void handle_topology_map(struct fw_card *card, struct fw_request *request,
1085 		int tcode, int destination, int source, int generation,
1086 		unsigned long long offset, void *payload, size_t length,
1087 		void *callback_data)
1088 {
1089 	int start;
1090 
1091 	if (!TCODE_IS_READ_REQUEST(tcode)) {
1092 		fw_send_response(card, request, RCODE_TYPE_ERROR);
1093 		return;
1094 	}
1095 
1096 	if ((offset & 3) > 0 || (length & 3) > 0) {
1097 		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
1098 		return;
1099 	}
1100 
1101 	start = (offset - topology_map_region.start) / 4;
1102 	memcpy(payload, &card->topology_map[start], length);
1103 
1104 	fw_send_response(card, request, RCODE_COMPLETE);
1105 }
1106 
1107 static struct fw_address_handler topology_map = {
1108 	.length			= 0x400,
1109 	.address_callback	= handle_topology_map,
1110 };
1111 
1112 static const struct fw_address_region registers_region =
1113 	{ .start = CSR_REGISTER_BASE,
1114 	  .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM, };
1115 
1116 static void update_split_timeout(struct fw_card *card)
1117 {
1118 	unsigned int cycles;
1119 
1120 	cycles = card->split_timeout_hi * 8000 + (card->split_timeout_lo >> 19);
1121 
1122 	/* minimum per IEEE 1394, maximum which doesn't overflow OHCI */
1123 	cycles = clamp(cycles, 800u, 3u * 8000u);
1124 
1125 	card->split_timeout_cycles = cycles;
1126 	card->split_timeout_jiffies = DIV_ROUND_UP(cycles * HZ, 8000);
1127 }
1128 
1129 static void handle_registers(struct fw_card *card, struct fw_request *request,
1130 		int tcode, int destination, int source, int generation,
1131 		unsigned long long offset, void *payload, size_t length,
1132 		void *callback_data)
1133 {
1134 	int reg = offset & ~CSR_REGISTER_BASE;
1135 	__be32 *data = payload;
1136 	int rcode = RCODE_COMPLETE;
1137 	unsigned long flags;
1138 
1139 	switch (reg) {
1140 	case CSR_PRIORITY_BUDGET:
1141 		if (!card->priority_budget_implemented) {
1142 			rcode = RCODE_ADDRESS_ERROR;
1143 			break;
1144 		}
1145 		fallthrough;
1146 
1147 	case CSR_NODE_IDS:
1148 		/*
1149 		 * per IEEE 1394-2008 8.3.22.3, not IEEE 1394.1-2004 3.2.8
1150 		 * and 9.6, but interoperable with IEEE 1394.1-2004 bridges
1151 		 */
1152 		fallthrough;
1153 
1154 	case CSR_STATE_CLEAR:
1155 	case CSR_STATE_SET:
1156 	case CSR_CYCLE_TIME:
1157 	case CSR_BUS_TIME:
1158 	case CSR_BUSY_TIMEOUT:
1159 		if (tcode == TCODE_READ_QUADLET_REQUEST)
1160 			*data = cpu_to_be32(card->driver->read_csr(card, reg));
1161 		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1162 			card->driver->write_csr(card, reg, be32_to_cpu(*data));
1163 		else
1164 			rcode = RCODE_TYPE_ERROR;
1165 		break;
1166 
1167 	case CSR_RESET_START:
1168 		if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1169 			card->driver->write_csr(card, CSR_STATE_CLEAR,
1170 						CSR_STATE_BIT_ABDICATE);
1171 		else
1172 			rcode = RCODE_TYPE_ERROR;
1173 		break;
1174 
1175 	case CSR_SPLIT_TIMEOUT_HI:
1176 		if (tcode == TCODE_READ_QUADLET_REQUEST) {
1177 			*data = cpu_to_be32(card->split_timeout_hi);
1178 		} else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1179 			spin_lock_irqsave(&card->lock, flags);
1180 			card->split_timeout_hi = be32_to_cpu(*data) & 7;
1181 			update_split_timeout(card);
1182 			spin_unlock_irqrestore(&card->lock, flags);
1183 		} else {
1184 			rcode = RCODE_TYPE_ERROR;
1185 		}
1186 		break;
1187 
1188 	case CSR_SPLIT_TIMEOUT_LO:
1189 		if (tcode == TCODE_READ_QUADLET_REQUEST) {
1190 			*data = cpu_to_be32(card->split_timeout_lo);
1191 		} else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1192 			spin_lock_irqsave(&card->lock, flags);
1193 			card->split_timeout_lo =
1194 					be32_to_cpu(*data) & 0xfff80000;
1195 			update_split_timeout(card);
1196 			spin_unlock_irqrestore(&card->lock, flags);
1197 		} else {
1198 			rcode = RCODE_TYPE_ERROR;
1199 		}
1200 		break;
1201 
1202 	case CSR_MAINT_UTILITY:
1203 		if (tcode == TCODE_READ_QUADLET_REQUEST)
1204 			*data = card->maint_utility_register;
1205 		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1206 			card->maint_utility_register = *data;
1207 		else
1208 			rcode = RCODE_TYPE_ERROR;
1209 		break;
1210 
1211 	case CSR_BROADCAST_CHANNEL:
1212 		if (tcode == TCODE_READ_QUADLET_REQUEST)
1213 			*data = cpu_to_be32(card->broadcast_channel);
1214 		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1215 			card->broadcast_channel =
1216 			    (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
1217 			    BROADCAST_CHANNEL_INITIAL;
1218 		else
1219 			rcode = RCODE_TYPE_ERROR;
1220 		break;
1221 
1222 	case CSR_BUS_MANAGER_ID:
1223 	case CSR_BANDWIDTH_AVAILABLE:
1224 	case CSR_CHANNELS_AVAILABLE_HI:
1225 	case CSR_CHANNELS_AVAILABLE_LO:
1226 		/*
1227 		 * FIXME: these are handled by the OHCI hardware and
1228 		 * the stack never sees these request. If we add
1229 		 * support for a new type of controller that doesn't
1230 		 * handle this in hardware we need to deal with these
1231 		 * transactions.
1232 		 */
1233 		BUG();
1234 		break;
1235 
1236 	default:
1237 		rcode = RCODE_ADDRESS_ERROR;
1238 		break;
1239 	}
1240 
1241 	fw_send_response(card, request, rcode);
1242 }
1243 
1244 static struct fw_address_handler registers = {
1245 	.length			= 0x400,
1246 	.address_callback	= handle_registers,
1247 };
1248 
1249 static void handle_low_memory(struct fw_card *card, struct fw_request *request,
1250 		int tcode, int destination, int source, int generation,
1251 		unsigned long long offset, void *payload, size_t length,
1252 		void *callback_data)
1253 {
1254 	/*
1255 	 * This catches requests not handled by the physical DMA unit,
1256 	 * i.e., wrong transaction types or unauthorized source nodes.
1257 	 */
1258 	fw_send_response(card, request, RCODE_TYPE_ERROR);
1259 }
1260 
1261 static struct fw_address_handler low_memory = {
1262 	.length			= FW_MAX_PHYSICAL_RANGE,
1263 	.address_callback	= handle_low_memory,
1264 };
1265 
1266 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1267 MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
1268 MODULE_LICENSE("GPL");
1269 
1270 static const u32 vendor_textual_descriptor[] = {
1271 	/* textual descriptor leaf () */
1272 	0x00060000,
1273 	0x00000000,
1274 	0x00000000,
1275 	0x4c696e75,		/* L i n u */
1276 	0x78204669,		/* x   F i */
1277 	0x72657769,		/* r e w i */
1278 	0x72650000,		/* r e     */
1279 };
1280 
1281 static const u32 model_textual_descriptor[] = {
1282 	/* model descriptor leaf () */
1283 	0x00030000,
1284 	0x00000000,
1285 	0x00000000,
1286 	0x4a756a75,		/* J u j u */
1287 };
1288 
1289 static struct fw_descriptor vendor_id_descriptor = {
1290 	.length = ARRAY_SIZE(vendor_textual_descriptor),
1291 	.immediate = 0x03001f11,
1292 	.key = 0x81000000,
1293 	.data = vendor_textual_descriptor,
1294 };
1295 
1296 static struct fw_descriptor model_id_descriptor = {
1297 	.length = ARRAY_SIZE(model_textual_descriptor),
1298 	.immediate = 0x17023901,
1299 	.key = 0x81000000,
1300 	.data = model_textual_descriptor,
1301 };
1302 
1303 static int __init fw_core_init(void)
1304 {
1305 	int ret;
1306 
1307 	fw_workqueue = alloc_workqueue("firewire", WQ_MEM_RECLAIM, 0);
1308 	if (!fw_workqueue)
1309 		return -ENOMEM;
1310 
1311 	ret = bus_register(&fw_bus_type);
1312 	if (ret < 0) {
1313 		destroy_workqueue(fw_workqueue);
1314 		return ret;
1315 	}
1316 
1317 	fw_cdev_major = register_chrdev(0, "firewire", &fw_device_ops);
1318 	if (fw_cdev_major < 0) {
1319 		bus_unregister(&fw_bus_type);
1320 		destroy_workqueue(fw_workqueue);
1321 		return fw_cdev_major;
1322 	}
1323 
1324 	fw_core_add_address_handler(&topology_map, &topology_map_region);
1325 	fw_core_add_address_handler(&registers, &registers_region);
1326 	fw_core_add_address_handler(&low_memory, &low_memory_region);
1327 	fw_core_add_descriptor(&vendor_id_descriptor);
1328 	fw_core_add_descriptor(&model_id_descriptor);
1329 
1330 	return 0;
1331 }
1332 
1333 static void __exit fw_core_cleanup(void)
1334 {
1335 	unregister_chrdev(fw_cdev_major, "firewire");
1336 	bus_unregister(&fw_bus_type);
1337 	destroy_workqueue(fw_workqueue);
1338 	idr_destroy(&fw_device_idr);
1339 }
1340 
1341 module_init(fw_core_init);
1342 module_exit(fw_core_cleanup);
1343