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