core-transaction.c

   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/jiffies.h>
  17#include <linux/kernel.h>
  18#include <linux/list.h>
  19#include <linux/module.h>
  20#include <linux/rculist.h>
  21#include <linux/slab.h>
  22#include <linux/spinlock.h>
  23#include <linux/string.h>
  24#include <linux/timer.h>
  25#include <linux/types.h>
  26#include <linux/workqueue.h>
  27
  28#include <asm/byteorder.h>
  29
  30#include "core.h"
  31#include "packet-header-definitions.h"
  32#include "phy-packet-definitions.h"
  33#include <trace/events/firewire.h>
  34
  35#define HEADER_DESTINATION_IS_BROADCAST(header) \
  36	((async_header_get_destination(header) & 0x3f) == 0x3f)
  37
  38/* returns 0 if the split timeout handler is already running */
  39static int try_cancel_split_timeout(struct fw_transaction *t)
  40{
  41	if (t->is_split_transaction)
  42		return timer_delete(&t->split_timeout_timer);
  43	else
  44		return 1;
  45}
  46
  47// card->transactions.lock must be acquired in advance.
  48static void remove_transaction_entry(struct fw_card *card, struct fw_transaction *entry)
  49{
  50	list_del_init(&entry->link);
  51	card->transactions.tlabel_mask &= ~(1ULL << entry->tlabel);
  52}
  53
  54// Must be called without holding card->transactions.lock.
  55void fw_cancel_pending_transactions(struct fw_card *card)
  56{
  57	struct fw_transaction *t, *tmp;
  58	LIST_HEAD(pending_list);
  59
  60	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
  61	// local destination never runs in any type of IRQ context.
  62	scoped_guard(spinlock_irqsave, &card->transactions.lock) {
  63		list_for_each_entry_safe(t, tmp, &card->transactions.list, link) {
  64			if (try_cancel_split_timeout(t))
  65				list_move(&t->link, &pending_list);
  66		}
  67	}
  68
  69	list_for_each_entry_safe(t, tmp, &pending_list, link) {
  70		list_del(&t->link);
  71
  72		if (!t->with_tstamp) {
  73			t->callback.without_tstamp(card, RCODE_CANCELLED, NULL, 0,
  74						   t->callback_data);
  75		} else {
  76			t->callback.with_tstamp(card, RCODE_CANCELLED, t->packet.timestamp, 0,
  77						NULL, 0, t->callback_data);
  78		}
  79	}
  80}
  81
  82// card->transactions.lock must be acquired in advance.
  83#define find_and_pop_transaction_entry(card, condition)			\
  84({									\
  85	struct fw_transaction *iter, *t = NULL;				\
  86	list_for_each_entry(iter, &card->transactions.list, link) {	\
  87		if (condition) {					\
  88			t = iter;					\
  89			break;						\
  90		}							\
  91	}								\
  92	if (t && try_cancel_split_timeout(t))				\
  93		remove_transaction_entry(card, t);			\
  94	t;								\
  95})
  96
  97static int close_transaction(struct fw_transaction *transaction, struct fw_card *card, int rcode,
  98			     u32 response_tstamp)
  99{
 100	struct fw_transaction *t;
 101
 102	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 103	// local destination never runs in any type of IRQ context.
 104	scoped_guard(spinlock_irqsave, &card->transactions.lock) {
 105		t = find_and_pop_transaction_entry(card, iter == transaction);
 106		if (!t)
 107			return -ENOENT;
 108	}
 109
 110	if (!t->with_tstamp) {
 111		t->callback.without_tstamp(card, rcode, NULL, 0, t->callback_data);
 112	} else {
 113		t->callback.with_tstamp(card, rcode, t->packet.timestamp, response_tstamp, NULL, 0,
 114					t->callback_data);
 115	}
 116
 117	return 0;
 118}
 119
 120/*
 121 * Only valid for transactions that are potentially pending (ie have
 122 * been sent).
 123 */
 124int fw_cancel_transaction(struct fw_card *card,
 125			  struct fw_transaction *transaction)
 126{
 127	u32 tstamp;
 128
 129	/*
 130	 * Cancel the packet transmission if it's still queued.  That
 131	 * will call the packet transmission callback which cancels
 132	 * the transaction.
 133	 */
 134
 135	if (card->driver->cancel_packet(card, &transaction->packet) == 0)
 136		return 0;
 137
 138	/*
 139	 * If the request packet has already been sent, we need to see
 140	 * if the transaction is still pending and remove it in that case.
 141	 */
 142
 143	if (transaction->packet.ack == 0) {
 144		// The timestamp is reused since it was just read now.
 145		tstamp = transaction->packet.timestamp;
 146	} else {
 147		u32 curr_cycle_time = 0;
 148
 149		(void)fw_card_read_cycle_time(card, &curr_cycle_time);
 150		tstamp = cycle_time_to_ohci_tstamp(curr_cycle_time);
 151	}
 152
 153	return close_transaction(transaction, card, RCODE_CANCELLED, tstamp);
 154}
 155EXPORT_SYMBOL(fw_cancel_transaction);
 156
 157static void split_transaction_timeout_callback(struct timer_list *timer)
 158{
 159	struct fw_transaction *t = timer_container_of(t, timer, split_timeout_timer);
 160	struct fw_card *card = t->card;
 161
 162	scoped_guard(spinlock_irqsave, &card->transactions.lock) {
 163		if (list_empty(&t->link))
 164			return;
 165		remove_transaction_entry(card, t);
 166	}
 167
 168	if (!t->with_tstamp) {
 169		t->callback.without_tstamp(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
 170	} else {
 171		t->callback.with_tstamp(card, RCODE_CANCELLED, t->packet.timestamp,
 172					t->split_timeout_cycle, NULL, 0, t->callback_data);
 173	}
 174}
 175
 176// card->transactions.lock should be acquired in advance for the linked list.
 177static void start_split_transaction_timeout(struct fw_transaction *t, unsigned int delta)
 178{
 179	if (list_empty(&t->link) || WARN_ON(t->is_split_transaction))
 180		return;
 181
 182	t->is_split_transaction = true;
 183
 184	mod_timer(&t->split_timeout_timer, jiffies + delta);
 185}
 186
 187static u32 compute_split_timeout_timestamp(struct fw_card *card, u32 request_timestamp);
 188
 189static void transmit_complete_callback(struct fw_packet *packet,
 190				       struct fw_card *card, int status)
 191{
 192	struct fw_transaction *t =
 193	    container_of(packet, struct fw_transaction, packet);
 194
 195	trace_async_request_outbound_complete((uintptr_t)t, card->index, packet->generation,
 196					      packet->speed, status, packet->timestamp);
 197
 198	switch (status) {
 199	case ACK_COMPLETE:
 200		close_transaction(t, card, RCODE_COMPLETE, packet->timestamp);
 201		break;
 202	case ACK_PENDING:
 203	{
 204		unsigned int delta;
 205
 206		// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 207		// local destination never runs in any type of IRQ context.
 208		scoped_guard(spinlock_irqsave, &card->split_timeout.lock) {
 209			t->split_timeout_cycle =
 210				compute_split_timeout_timestamp(card, packet->timestamp) & 0xffff;
 211			delta = card->split_timeout.jiffies;
 212		}
 213
 214		// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 215		// local destination never runs in any type of IRQ context.
 216		scoped_guard(spinlock_irqsave, &card->transactions.lock)
 217			start_split_transaction_timeout(t, delta);
 218		break;
 219	}
 220	case ACK_BUSY_X:
 221	case ACK_BUSY_A:
 222	case ACK_BUSY_B:
 223		close_transaction(t, card, RCODE_BUSY, packet->timestamp);
 224		break;
 225	case ACK_DATA_ERROR:
 226		close_transaction(t, card, RCODE_DATA_ERROR, packet->timestamp);
 227		break;
 228	case ACK_TYPE_ERROR:
 229		close_transaction(t, card, RCODE_TYPE_ERROR, packet->timestamp);
 230		break;
 231	default:
 232		/*
 233		 * In this case the ack is really a juju specific
 234		 * rcode, so just forward that to the callback.
 235		 */
 236		close_transaction(t, card, status, packet->timestamp);
 237		break;
 238	}
 239}
 240
 241static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
 242		int destination_id, int source_id, int generation, int speed,
 243		unsigned long long offset, void *payload, size_t length)
 244{
 245	int ext_tcode;
 246
 247	if (tcode == TCODE_STREAM_DATA) {
 248		// The value of destination_id argument should include tag, channel, and sy fields
 249		// as isochronous packet header has.
 250		packet->header[0] = destination_id;
 251		isoc_header_set_data_length(packet->header, length);
 252		isoc_header_set_tcode(packet->header, TCODE_STREAM_DATA);
 253		packet->header_length = 4;
 254		packet->payload = payload;
 255		packet->payload_length = length;
 256
 257		goto common;
 258	}
 259
 260	if (tcode > 0x10) {
 261		ext_tcode = tcode & ~0x10;
 262		tcode = TCODE_LOCK_REQUEST;
 263	} else
 264		ext_tcode = 0;
 265
 266	async_header_set_retry(packet->header, RETRY_X);
 267	async_header_set_tlabel(packet->header, tlabel);
 268	async_header_set_tcode(packet->header, tcode);
 269	async_header_set_destination(packet->header, destination_id);
 270	async_header_set_source(packet->header, source_id);
 271	async_header_set_offset(packet->header, offset);
 272
 273	switch (tcode) {
 274	case TCODE_WRITE_QUADLET_REQUEST:
 275		async_header_set_quadlet_data(packet->header, *(u32 *)payload);
 276		packet->header_length = 16;
 277		packet->payload_length = 0;
 278		break;
 279
 280	case TCODE_LOCK_REQUEST:
 281	case TCODE_WRITE_BLOCK_REQUEST:
 282		async_header_set_data_length(packet->header, length);
 283		async_header_set_extended_tcode(packet->header, ext_tcode);
 284		packet->header_length = 16;
 285		packet->payload = payload;
 286		packet->payload_length = length;
 287		break;
 288
 289	case TCODE_READ_QUADLET_REQUEST:
 290		packet->header_length = 12;
 291		packet->payload_length = 0;
 292		break;
 293
 294	case TCODE_READ_BLOCK_REQUEST:
 295		async_header_set_data_length(packet->header, length);
 296		async_header_set_extended_tcode(packet->header, ext_tcode);
 297		packet->header_length = 16;
 298		packet->payload_length = 0;
 299		break;
 300
 301	default:
 302		WARN(1, "wrong tcode %d\n", tcode);
 303	}
 304 common:
 305	packet->speed = speed;
 306	packet->generation = generation;
 307	packet->ack = 0;
 308	packet->payload_mapped = false;
 309}
 310
 311static int allocate_tlabel(struct fw_card *card)
 312__must_hold(&card->transactions.lock)
 313{
 314	int tlabel;
 315
 316	lockdep_assert_held(&card->transactions.lock);
 317
 318	tlabel = card->transactions.current_tlabel;
 319	while (card->transactions.tlabel_mask & (1ULL << tlabel)) {
 320		tlabel = (tlabel + 1) & 0x3f;
 321		if (tlabel == card->transactions.current_tlabel)
 322			return -EBUSY;
 323	}
 324
 325	card->transactions.current_tlabel = (tlabel + 1) & 0x3f;
 326	card->transactions.tlabel_mask |= 1ULL << tlabel;
 327
 328	return tlabel;
 329}
 330
 331/**
 332 * __fw_send_request() - submit a request packet for transmission to generate callback for response
 333 *			 subaction with or without time stamp.
 334 * @card:		interface to send the request at
 335 * @t:			transaction instance to which the request belongs
 336 * @tcode:		transaction code
 337 * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
 338 * @generation:		bus generation in which request and response are valid
 339 * @speed:		transmission speed
 340 * @offset:		48bit wide offset into destination's address space
 341 * @payload:		data payload for the request subaction
 342 * @length:		length of the payload, in bytes
 343 * @callback:		union of two functions whether to receive time stamp or not for response
 344 *			subaction.
 345 * @with_tstamp:	Whether to receive time stamp or not for response subaction.
 346 * @callback_data:	data to be passed to the transaction completion callback
 347 *
 348 * Submit a request packet into the asynchronous request transmission queue.
 349 * Can be called from atomic context.  If you prefer a blocking API, use
 350 * fw_run_transaction() in a context that can sleep.
 351 *
 352 * In case of lock requests, specify one of the firewire-core specific %TCODE_
 353 * constants instead of %TCODE_LOCK_REQUEST in @tcode.
 354 *
 355 * Make sure that the value in @destination_id is not older than the one in
 356 * @generation.  Otherwise the request is in danger to be sent to a wrong node.
 357 *
 358 * In case of asynchronous stream packets i.e. %TCODE_STREAM_DATA, the caller
 359 * needs to synthesize @destination_id with fw_stream_packet_destination_id().
 360 * It will contain tag, channel, and sy data instead of a node ID then.
 361 *
 362 * The payload buffer at @data is going to be DMA-mapped except in case of
 363 * @length <= 8 or of local (loopback) requests.  Hence make sure that the
 364 * buffer complies with the restrictions of the streaming DMA mapping API.
 365 * @payload must not be freed before the @callback is called.
 366 *
 367 * In case of request types without payload, @data is NULL and @length is 0.
 368 *
 369 * After the transaction is completed successfully or unsuccessfully, the
 370 * @callback will be called.  Among its parameters is the response code which
 371 * is either one of the rcodes per IEEE 1394 or, in case of internal errors,
 372 * the firewire-core specific %RCODE_SEND_ERROR.  The other firewire-core
 373 * specific rcodes (%RCODE_CANCELLED, %RCODE_BUSY, %RCODE_GENERATION,
 374 * %RCODE_NO_ACK) denote transaction timeout, busy responder, stale request
 375 * generation, or missing ACK respectively.
 376 *
 377 * Note some timing corner cases:  fw_send_request() may complete much earlier
 378 * than when the request packet actually hits the wire.  On the other hand,
 379 * transaction completion and hence execution of @callback may happen even
 380 * before fw_send_request() returns.
 381 */
 382void __fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
 383		int destination_id, int generation, int speed, unsigned long long offset,
 384		void *payload, size_t length, union fw_transaction_callback callback,
 385		bool with_tstamp, void *callback_data)
 386{
 387	int tlabel;
 388
 389	/*
 390	 * Allocate tlabel from the bitmap and put the transaction on
 391	 * the list while holding the card spinlock.
 392	 */
 393
 394	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 395	// local destination never runs in any type of IRQ context.
 396	scoped_guard(spinlock_irqsave, &card->transactions.lock)
 397		tlabel = allocate_tlabel(card);
 398	if (tlabel < 0) {
 399		if (!with_tstamp) {
 400			callback.without_tstamp(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
 401		} else {
 402			// Timestamping on behalf of hardware.
 403			u32 curr_cycle_time = 0;
 404			u32 tstamp;
 405
 406			(void)fw_card_read_cycle_time(card, &curr_cycle_time);
 407			tstamp = cycle_time_to_ohci_tstamp(curr_cycle_time);
 408
 409			callback.with_tstamp(card, RCODE_SEND_ERROR, tstamp, tstamp, NULL, 0,
 410					     callback_data);
 411		}
 412		return;
 413	}
 414
 415	t->node_id = destination_id;
 416	t->tlabel = tlabel;
 417	t->card = card;
 418	t->is_split_transaction = false;
 419	timer_setup(&t->split_timeout_timer, split_transaction_timeout_callback, 0);
 420	t->callback = callback;
 421	t->with_tstamp = with_tstamp;
 422	t->callback_data = callback_data;
 423	t->packet.callback = transmit_complete_callback;
 424
 425	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 426	// local destination never runs in any type of IRQ context.
 427	scoped_guard(spinlock_irqsave, &card->lock) {
 428		// The node_id field of fw_card can be updated when handling SelfIDComplete.
 429		fw_fill_request(&t->packet, tcode, t->tlabel, destination_id, card->node_id,
 430				generation, speed, offset, payload, length);
 431	}
 432
 433	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 434	// local destination never runs in any type of IRQ context.
 435	scoped_guard(spinlock_irqsave, &card->transactions.lock)
 436		list_add_tail(&t->link, &card->transactions.list);
 437
 438	// Safe with no lock, since the index field of fw_card is immutable once assigned.
 439	trace_async_request_outbound_initiate((uintptr_t)t, card->index, generation, speed,
 440					      t->packet.header, payload,
 441					      tcode_is_read_request(tcode) ? 0 : length / 4);
 442
 443	card->driver->send_request(card, &t->packet);
 444}
 445EXPORT_SYMBOL_GPL(__fw_send_request);
 446
 447struct transaction_callback_data {
 448	struct completion done;
 449	void *payload;
 450	int rcode;
 451};
 452
 453static void transaction_callback(struct fw_card *card, int rcode,
 454				 void *payload, size_t length, void *data)
 455{
 456	struct transaction_callback_data *d = data;
 457
 458	if (rcode == RCODE_COMPLETE)
 459		memcpy(d->payload, payload, length);
 460	d->rcode = rcode;
 461	complete(&d->done);
 462}
 463
 464/**
 465 * fw_run_transaction() - send request and sleep until transaction is completed
 466 * @card:		card interface for this request
 467 * @tcode:		transaction code
 468 * @destination_id:	destination node ID, consisting of bus_ID and phy_ID
 469 * @generation:		bus generation in which request and response are valid
 470 * @speed:		transmission speed
 471 * @offset:		48bit wide offset into destination's address space
 472 * @payload:		data payload for the request subaction
 473 * @length:		length of the payload, in bytes
 474 *
 475 * Returns the RCODE.  See fw_send_request() for parameter documentation.
 476 * Unlike fw_send_request(), @data points to the payload of the request or/and
 477 * to the payload of the response.  DMA mapping restrictions apply to outbound
 478 * request payloads of >= 8 bytes but not to inbound response payloads.
 479 */
 480int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
 481		       int generation, int speed, unsigned long long offset,
 482		       void *payload, size_t length)
 483{
 484	struct transaction_callback_data d;
 485	struct fw_transaction t;
 486
 487	timer_setup_on_stack(&t.split_timeout_timer, NULL, 0);
 488	init_completion(&d.done);
 489	d.payload = payload;
 490	fw_send_request(card, &t, tcode, destination_id, generation, speed,
 491			offset, payload, length, transaction_callback, &d);
 492	wait_for_completion(&d.done);
 493	timer_destroy_on_stack(&t.split_timeout_timer);
 494
 495	return d.rcode;
 496}
 497EXPORT_SYMBOL(fw_run_transaction);
 498
 499static DEFINE_MUTEX(phy_config_mutex);
 500static DECLARE_COMPLETION(phy_config_done);
 501
 502static void transmit_phy_packet_callback(struct fw_packet *packet,
 503					 struct fw_card *card, int status)
 504{
 505	trace_async_phy_outbound_complete((uintptr_t)packet, card->index, packet->generation, status,
 506					  packet->timestamp);
 507	complete(&phy_config_done);
 508}
 509
 510static struct fw_packet phy_config_packet = {
 511	.header_length	= 12,
 512	.payload_length	= 0,
 513	.speed		= SCODE_100,
 514	.callback	= transmit_phy_packet_callback,
 515};
 516
 517void fw_send_phy_config(struct fw_card *card,
 518			int node_id, int generation, int gap_count)
 519{
 520	long timeout = msecs_to_jiffies(100);
 521	u32 data = 0;
 522
 523	phy_packet_set_packet_identifier(&data, PHY_PACKET_PACKET_IDENTIFIER_PHY_CONFIG);
 524
 525	if (node_id != FW_PHY_CONFIG_NO_NODE_ID) {
 526		phy_packet_phy_config_set_root_id(&data, node_id);
 527		phy_packet_phy_config_set_force_root_node(&data, true);
 528	}
 529
 530	if (gap_count == FW_PHY_CONFIG_CURRENT_GAP_COUNT) {
 531		gap_count = card->driver->read_phy_reg(card, 1);
 532		if (gap_count < 0)
 533			return;
 534
 535		gap_count &= 63;
 536		if (gap_count == 63)
 537			return;
 538	}
 539	phy_packet_phy_config_set_gap_count(&data, gap_count);
 540	phy_packet_phy_config_set_gap_count_optimization(&data, true);
 541
 542	guard(mutex)(&phy_config_mutex);
 543
 544	async_header_set_tcode(phy_config_packet.header, TCODE_LINK_INTERNAL);
 545	phy_config_packet.header[1] = data;
 546	phy_config_packet.header[2] = ~data;
 547	phy_config_packet.generation = generation;
 548	reinit_completion(&phy_config_done);
 549
 550	trace_async_phy_outbound_initiate((uintptr_t)&phy_config_packet, card->index,
 551					  phy_config_packet.generation, phy_config_packet.header[1],
 552					  phy_config_packet.header[2]);
 553
 554	card->driver->send_request(card, &phy_config_packet);
 555	wait_for_completion_timeout(&phy_config_done, timeout);
 556}
 557
 558static struct fw_address_handler *lookup_overlapping_address_handler(
 559	struct list_head *list, unsigned long long offset, size_t length)
 560{
 561	struct fw_address_handler *handler;
 562
 563	list_for_each_entry_rcu(handler, list, link) {
 564		if (handler->offset < offset + length &&
 565		    offset < handler->offset + handler->length)
 566			return handler;
 567	}
 568
 569	return NULL;
 570}
 571
 572static bool is_enclosing_handler(struct fw_address_handler *handler,
 573				 unsigned long long offset, size_t length)
 574{
 575	return handler->offset <= offset &&
 576		offset + length <= handler->offset + handler->length;
 577}
 578
 579static struct fw_address_handler *lookup_enclosing_address_handler(
 580	struct list_head *list, unsigned long long offset, size_t length)
 581{
 582	struct fw_address_handler *handler;
 583
 584	list_for_each_entry_rcu(handler, list, link) {
 585		if (is_enclosing_handler(handler, offset, length))
 586			return handler;
 587	}
 588
 589	return NULL;
 590}
 591
 592static DEFINE_SPINLOCK(address_handler_list_lock);
 593static LIST_HEAD(address_handler_list);
 594
 595const struct fw_address_region fw_high_memory_region =
 596	{ .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
 597EXPORT_SYMBOL(fw_high_memory_region);
 598
 599static const struct fw_address_region low_memory_region =
 600	{ .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
 601
 602#if 0
 603const struct fw_address_region fw_private_region =
 604	{ .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
 605const struct fw_address_region fw_csr_region =
 606	{ .start = CSR_REGISTER_BASE,
 607	  .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM_END,  };
 608const struct fw_address_region fw_unit_space_region =
 609	{ .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
 610#endif  /*  0  */
 611
 612static void complete_address_handler(struct kref *kref)
 613{
 614	struct fw_address_handler *handler = container_of(kref, struct fw_address_handler, kref);
 615
 616	complete(&handler->done);
 617}
 618
 619static void get_address_handler(struct fw_address_handler *handler)
 620{
 621	kref_get(&handler->kref);
 622}
 623
 624static int put_address_handler(struct fw_address_handler *handler)
 625{
 626	return kref_put(&handler->kref, complete_address_handler);
 627}
 628
 629/**
 630 * fw_core_add_address_handler() - register for incoming requests
 631 * @handler:	callback
 632 * @region:	region in the IEEE 1212 node space address range
 633 *
 634 * region->start, ->end, and handler->length have to be quadlet-aligned.
 635 *
 636 * When a request is received that falls within the specified address range, the specified callback
 637 * is invoked.  The parameters passed to the callback give the details of the particular request.
 638 * The callback is invoked in the workqueue context in most cases. However, if the request is
 639 * initiated by the local node, the callback is invoked in the initiator's context.
 640 *
 641 * To be called in process context.
 642 * Return value:  0 on success, non-zero otherwise.
 643 *
 644 * The start offset of the handler's address region is determined by
 645 * fw_core_add_address_handler() and is returned in handler->offset.
 646 *
 647 * Address allocations are exclusive, except for the FCP registers.
 648 */
 649int fw_core_add_address_handler(struct fw_address_handler *handler,
 650				const struct fw_address_region *region)
 651{
 652	struct fw_address_handler *other;
 653	int ret = -EBUSY;
 654
 655	if (region->start & 0xffff000000000003ULL ||
 656	    region->start >= region->end ||
 657	    region->end   > 0x0001000000000000ULL ||
 658	    handler->length & 3 ||
 659	    handler->length == 0)
 660		return -EINVAL;
 661
 662	guard(spinlock)(&address_handler_list_lock);
 663
 664	handler->offset = region->start;
 665	while (handler->offset + handler->length <= region->end) {
 666		if (is_in_fcp_region(handler->offset, handler->length))
 667			other = NULL;
 668		else
 669			other = lookup_overlapping_address_handler
 670					(&address_handler_list,
 671					 handler->offset, handler->length);
 672		if (other != NULL) {
 673			handler->offset += other->length;
 674		} else {
 675			init_completion(&handler->done);
 676			kref_init(&handler->kref);
 677			list_add_tail_rcu(&handler->link, &address_handler_list);
 678			ret = 0;
 679			break;
 680		}
 681	}
 682
 683	return ret;
 684}
 685EXPORT_SYMBOL(fw_core_add_address_handler);
 686
 687/**
 688 * fw_core_remove_address_handler() - unregister an address handler
 689 * @handler: callback
 690 *
 691 * To be called in process context.
 692 *
 693 * When fw_core_remove_address_handler() returns, @handler->callback() is
 694 * guaranteed to not run on any CPU anymore.
 695 */
 696void fw_core_remove_address_handler(struct fw_address_handler *handler)
 697{
 698	scoped_guard(spinlock, &address_handler_list_lock)
 699		list_del_rcu(&handler->link);
 700
 701	synchronize_rcu();
 702
 703	if (!put_address_handler(handler))
 704		wait_for_completion(&handler->done);
 705}
 706EXPORT_SYMBOL(fw_core_remove_address_handler);
 707
 708struct fw_request {
 709	struct kref kref;
 710	struct fw_packet response;
 711	u32 request_header[ASYNC_HEADER_QUADLET_COUNT];
 712	int ack;
 713	u32 timestamp;
 714	u32 length;
 715	u32 data[];
 716};
 717
 718void fw_request_get(struct fw_request *request)
 719{
 720	kref_get(&request->kref);
 721}
 722
 723static void release_request(struct kref *kref)
 724{
 725	struct fw_request *request = container_of(kref, struct fw_request, kref);
 726
 727	kfree(request);
 728}
 729
 730void fw_request_put(struct fw_request *request)
 731{
 732	kref_put(&request->kref, release_request);
 733}
 734
 735static void free_response_callback(struct fw_packet *packet,
 736				   struct fw_card *card, int status)
 737{
 738	struct fw_request *request = container_of(packet, struct fw_request, response);
 739
 740	trace_async_response_outbound_complete((uintptr_t)request, card->index, packet->generation,
 741					       packet->speed, status, packet->timestamp);
 742
 743	// Decrease the reference count since not at in-flight.
 744	fw_request_put(request);
 745
 746	// Decrease the reference count to release the object.
 747	fw_request_put(request);
 748}
 749
 750int fw_get_response_length(struct fw_request *r)
 751{
 752	int tcode, ext_tcode, data_length;
 753
 754	tcode = async_header_get_tcode(r->request_header);
 755
 756	switch (tcode) {
 757	case TCODE_WRITE_QUADLET_REQUEST:
 758	case TCODE_WRITE_BLOCK_REQUEST:
 759		return 0;
 760
 761	case TCODE_READ_QUADLET_REQUEST:
 762		return 4;
 763
 764	case TCODE_READ_BLOCK_REQUEST:
 765		data_length = async_header_get_data_length(r->request_header);
 766		return data_length;
 767
 768	case TCODE_LOCK_REQUEST:
 769		ext_tcode = async_header_get_extended_tcode(r->request_header);
 770		data_length = async_header_get_data_length(r->request_header);
 771		switch (ext_tcode) {
 772		case EXTCODE_FETCH_ADD:
 773		case EXTCODE_LITTLE_ADD:
 774			return data_length;
 775		default:
 776			return data_length / 2;
 777		}
 778
 779	default:
 780		WARN(1, "wrong tcode %d\n", tcode);
 781		return 0;
 782	}
 783}
 784
 785void fw_fill_response(struct fw_packet *response, u32 *request_header,
 786		      int rcode, void *payload, size_t length)
 787{
 788	int tcode, tlabel, extended_tcode, source, destination;
 789
 790	tcode = async_header_get_tcode(request_header);
 791	tlabel = async_header_get_tlabel(request_header);
 792	source = async_header_get_destination(request_header); // Exchange.
 793	destination = async_header_get_source(request_header); // Exchange.
 794	extended_tcode = async_header_get_extended_tcode(request_header);
 795
 796	async_header_set_retry(response->header, RETRY_1);
 797	async_header_set_tlabel(response->header, tlabel);
 798	async_header_set_destination(response->header, destination);
 799	async_header_set_source(response->header, source);
 800	async_header_set_rcode(response->header, rcode);
 801	response->header[2] = 0;	// The field is reserved.
 802
 803	switch (tcode) {
 804	case TCODE_WRITE_QUADLET_REQUEST:
 805	case TCODE_WRITE_BLOCK_REQUEST:
 806		async_header_set_tcode(response->header, TCODE_WRITE_RESPONSE);
 807		response->header_length = 12;
 808		response->payload_length = 0;
 809		break;
 810
 811	case TCODE_READ_QUADLET_REQUEST:
 812		async_header_set_tcode(response->header, TCODE_READ_QUADLET_RESPONSE);
 813		if (payload != NULL)
 814			async_header_set_quadlet_data(response->header, *(u32 *)payload);
 815		else
 816			async_header_set_quadlet_data(response->header, 0);
 817		response->header_length = 16;
 818		response->payload_length = 0;
 819		break;
 820
 821	case TCODE_READ_BLOCK_REQUEST:
 822	case TCODE_LOCK_REQUEST:
 823		async_header_set_tcode(response->header, tcode + 2);
 824		async_header_set_data_length(response->header, length);
 825		async_header_set_extended_tcode(response->header, extended_tcode);
 826		response->header_length = 16;
 827		response->payload = payload;
 828		response->payload_length = length;
 829		break;
 830
 831	default:
 832		WARN(1, "wrong tcode %d\n", tcode);
 833	}
 834
 835	response->payload_mapped = false;
 836}
 837EXPORT_SYMBOL(fw_fill_response);
 838
 839static u32 compute_split_timeout_timestamp(struct fw_card *card,
 840					   u32 request_timestamp)
 841__must_hold(&card->split_timeout.lock)
 842{
 843	unsigned int cycles;
 844	u32 timestamp;
 845
 846	lockdep_assert_held(&card->split_timeout.lock);
 847
 848	cycles = card->split_timeout.cycles;
 849	cycles += request_timestamp & 0x1fff;
 850
 851	timestamp = request_timestamp & ~0x1fff;
 852	timestamp += (cycles / 8000) << 13;
 853	timestamp |= cycles % 8000;
 854
 855	return timestamp;
 856}
 857
 858static struct fw_request *allocate_request(struct fw_card *card,
 859					   struct fw_packet *p)
 860{
 861	struct fw_request *request;
 862	u32 *data, length;
 863	int request_tcode;
 864
 865	request_tcode = async_header_get_tcode(p->header);
 866	switch (request_tcode) {
 867	case TCODE_WRITE_QUADLET_REQUEST:
 868		data = &p->header[3];
 869		length = 4;
 870		break;
 871
 872	case TCODE_WRITE_BLOCK_REQUEST:
 873	case TCODE_LOCK_REQUEST:
 874		data = p->payload;
 875		length = async_header_get_data_length(p->header);
 876		break;
 877
 878	case TCODE_READ_QUADLET_REQUEST:
 879		data = NULL;
 880		length = 4;
 881		break;
 882
 883	case TCODE_READ_BLOCK_REQUEST:
 884		data = NULL;
 885		length = async_header_get_data_length(p->header);
 886		break;
 887
 888	default:
 889		fw_notice(card, "ERROR - corrupt request received - %08x %08x %08x\n",
 890			 p->header[0], p->header[1], p->header[2]);
 891		return NULL;
 892	}
 893
 894	request = kmalloc(sizeof(*request) + length, GFP_ATOMIC);
 895	if (request == NULL)
 896		return NULL;
 897	kref_init(&request->kref);
 898
 899	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
 900	// local destination never runs in any type of IRQ context.
 901	scoped_guard(spinlock_irqsave, &card->split_timeout.lock)
 902		request->response.timestamp = compute_split_timeout_timestamp(card, p->timestamp);
 903
 904	request->response.speed = p->speed;
 905	request->response.generation = p->generation;
 906	request->response.ack = 0;
 907	request->response.callback = free_response_callback;
 908	request->ack = p->ack;
 909	request->timestamp = p->timestamp;
 910	request->length = length;
 911	if (data)
 912		memcpy(request->data, data, length);
 913
 914	memcpy(request->request_header, p->header, sizeof(p->header));
 915
 916	return request;
 917}
 918
 919/**
 920 * fw_send_response: - send response packet for asynchronous transaction.
 921 * @card:	interface to send the response at.
 922 * @request:	firewire request data for the transaction.
 923 * @rcode:	response code to send.
 924 *
 925 * Submit a response packet into the asynchronous response transmission queue. The @request
 926 * is going to be released when the transmission successfully finishes later.
 927 */
 928void fw_send_response(struct fw_card *card,
 929		      struct fw_request *request, int rcode)
 930{
 931	u32 *data = NULL;
 932	unsigned int data_length = 0;
 933
 934	/* unified transaction or broadcast transaction: don't respond */
 935	if (request->ack != ACK_PENDING ||
 936	    HEADER_DESTINATION_IS_BROADCAST(request->request_header)) {
 937		fw_request_put(request);
 938		return;
 939	}
 940
 941	if (rcode == RCODE_COMPLETE) {
 942		data = request->data;
 943		data_length = fw_get_response_length(request);
 944	}
 945
 946	fw_fill_response(&request->response, request->request_header, rcode, data, data_length);
 947
 948	// Increase the reference count so that the object is kept during in-flight.
 949	fw_request_get(request);
 950
 951	trace_async_response_outbound_initiate((uintptr_t)request, card->index,
 952					       request->response.generation, request->response.speed,
 953					       request->response.header, data,
 954					       data ? data_length / 4 : 0);
 955
 956	card->driver->send_response(card, &request->response);
 957}
 958EXPORT_SYMBOL(fw_send_response);
 959
 960/**
 961 * fw_get_request_speed() - returns speed at which the @request was received
 962 * @request: firewire request data
 963 */
 964int fw_get_request_speed(struct fw_request *request)
 965{
 966	return request->response.speed;
 967}
 968EXPORT_SYMBOL(fw_get_request_speed);
 969
 970/**
 971 * fw_request_get_timestamp: Get timestamp of the request.
 972 * @request: The opaque pointer to request structure.
 973 *
 974 * Get timestamp when 1394 OHCI controller receives the asynchronous request subaction. The
 975 * timestamp consists of the low order 3 bits of second field and the full 13 bits of count
 976 * field of isochronous cycle time register.
 977 *
 978 * Returns: timestamp of the request.
 979 */
 980u32 fw_request_get_timestamp(const struct fw_request *request)
 981{
 982	return request->timestamp;
 983}
 984EXPORT_SYMBOL_GPL(fw_request_get_timestamp);
 985
 986static void handle_exclusive_region_request(struct fw_card *card,
 987					    struct fw_packet *p,
 988					    struct fw_request *request,
 989					    unsigned long long offset)
 990{
 991	struct fw_address_handler *handler;
 992	int tcode, destination, source;
 993
 994	destination = async_header_get_destination(p->header);
 995	source = async_header_get_source(p->header);
 996	tcode = async_header_get_tcode(p->header);
 997	if (tcode == TCODE_LOCK_REQUEST)
 998		tcode = 0x10 + async_header_get_extended_tcode(p->header);
 999
1000	scoped_guard(rcu) {
1001		handler = lookup_enclosing_address_handler(&address_handler_list, offset,
1002							   request->length);
1003		if (handler)
1004			get_address_handler(handler);
1005	}
1006
1007	if (!handler) {
1008		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
1009		return;
1010	}
1011
1012	// Outside the RCU read-side critical section. Without spinlock. With reference count.
1013	handler->address_callback(card, request, tcode, destination, source, p->generation, offset,
1014				  request->data, request->length, handler->callback_data);
1015	put_address_handler(handler);
1016}
1017
1018// To use kmalloc allocator efficiently, this should be power of two.
1019#define BUFFER_ON_KERNEL_STACK_SIZE	4
1020
1021static void handle_fcp_region_request(struct fw_card *card,
1022				      struct fw_packet *p,
1023				      struct fw_request *request,
1024				      unsigned long long offset)
1025{
1026	struct fw_address_handler *buffer_on_kernel_stack[BUFFER_ON_KERNEL_STACK_SIZE];
1027	struct fw_address_handler *handler, **handlers;
1028	int tcode, destination, source, i, count, buffer_size;
1029
1030	if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
1031	     offset != (CSR_REGISTER_BASE | CSR_FCP_RESPONSE)) ||
1032	    request->length > 0x200) {
1033		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
1034
1035		return;
1036	}
1037
1038	tcode = async_header_get_tcode(p->header);
1039	destination = async_header_get_destination(p->header);
1040	source = async_header_get_source(p->header);
1041
1042	if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
1043	    tcode != TCODE_WRITE_BLOCK_REQUEST) {
1044		fw_send_response(card, request, RCODE_TYPE_ERROR);
1045
1046		return;
1047	}
1048
1049	count = 0;
1050	handlers = buffer_on_kernel_stack;
1051	buffer_size = ARRAY_SIZE(buffer_on_kernel_stack);
1052	scoped_guard(rcu) {
1053		list_for_each_entry_rcu(handler, &address_handler_list, link) {
1054			if (is_enclosing_handler(handler, offset, request->length)) {
1055				if (count >= buffer_size) {
1056					int next_size = buffer_size * 2;
1057					struct fw_address_handler **buffer_on_kernel_heap;
1058
1059					if (handlers == buffer_on_kernel_stack)
1060						buffer_on_kernel_heap = NULL;
1061					else
1062						buffer_on_kernel_heap = handlers;
1063
1064					buffer_on_kernel_heap =
1065						krealloc_array(buffer_on_kernel_heap, next_size,
1066							sizeof(*buffer_on_kernel_heap), GFP_ATOMIC);
1067					// FCP is used for purposes unrelated to significant system
1068					// resources (e.g. storage or networking), so allocation
1069					// failures are not considered so critical.
1070					if (!buffer_on_kernel_heap)
1071						break;
1072
1073					if (handlers == buffer_on_kernel_stack) {
1074						memcpy(buffer_on_kernel_heap, buffer_on_kernel_stack,
1075						       sizeof(buffer_on_kernel_stack));
1076					}
1077
1078					handlers = buffer_on_kernel_heap;
1079					buffer_size = next_size;
1080				}
1081				get_address_handler(handler);
1082				handlers[count++] = handler;
1083			}
1084		}
1085	}
1086
1087	for (i = 0; i < count; ++i) {
1088		handler = handlers[i];
1089		handler->address_callback(card, request, tcode, destination, source,
1090					  p->generation, offset, request->data,
1091					  request->length, handler->callback_data);
1092		put_address_handler(handler);
1093	}
1094
1095	if (handlers != buffer_on_kernel_stack)
1096		kfree(handlers);
1097
1098	fw_send_response(card, request, RCODE_COMPLETE);
1099}
1100
1101void fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
1102{
1103	struct fw_request *request;
1104	unsigned long long offset;
1105	unsigned int tcode;
1106
1107	if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
1108		return;
1109
1110	tcode = async_header_get_tcode(p->header);
1111	if (tcode_is_link_internal(tcode)) {
1112		trace_async_phy_inbound((uintptr_t)p, card->index, p->generation, p->ack, p->timestamp,
1113					 p->header[1], p->header[2]);
1114		fw_cdev_handle_phy_packet(card, p);
1115		return;
1116	}
1117
1118	request = allocate_request(card, p);
1119	if (request == NULL) {
1120		/* FIXME: send statically allocated busy packet. */
1121		return;
1122	}
1123
1124	trace_async_request_inbound((uintptr_t)request, card->index, p->generation, p->speed,
1125				    p->ack, p->timestamp, p->header, request->data,
1126				    tcode_is_read_request(tcode) ? 0 : request->length / 4);
1127
1128	offset = async_header_get_offset(p->header);
1129
1130	if (!is_in_fcp_region(offset, request->length))
1131		handle_exclusive_region_request(card, p, request, offset);
1132	else
1133		handle_fcp_region_request(card, p, request, offset);
1134
1135}
1136EXPORT_SYMBOL(fw_core_handle_request);
1137
1138void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
1139{
1140	struct fw_transaction *t = NULL;
1141	u32 *data;
1142	size_t data_length;
1143	int tcode, tlabel, source, rcode;
1144
1145	tcode = async_header_get_tcode(p->header);
1146	tlabel = async_header_get_tlabel(p->header);
1147	source = async_header_get_source(p->header);
1148	rcode = async_header_get_rcode(p->header);
1149
1150	// FIXME: sanity check packet, is length correct, does tcodes
1151	// and addresses match to the transaction request queried later.
1152	//
1153	// For the tracepoints event, let us decode the header here against the concern.
1154
1155	switch (tcode) {
1156	case TCODE_READ_QUADLET_RESPONSE:
1157		data = (u32 *) &p->header[3];
1158		data_length = 4;
1159		break;
1160
1161	case TCODE_WRITE_RESPONSE:
1162		data = NULL;
1163		data_length = 0;
1164		break;
1165
1166	case TCODE_READ_BLOCK_RESPONSE:
1167	case TCODE_LOCK_RESPONSE:
1168		data = p->payload;
1169		data_length = async_header_get_data_length(p->header);
1170		break;
1171
1172	default:
1173		/* Should never happen, this is just to shut up gcc. */
1174		data = NULL;
1175		data_length = 0;
1176		break;
1177	}
1178
1179	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
1180	// local destination never runs in any type of IRQ context.
1181	scoped_guard(spinlock_irqsave, &card->transactions.lock) {
1182		t = find_and_pop_transaction_entry(card,
1183				iter->node_id == source && iter->tlabel == tlabel);
1184	}
1185
1186	trace_async_response_inbound((uintptr_t)t, card->index, p->generation, p->speed, p->ack,
1187				     p->timestamp, p->header, data, data_length / 4);
1188
1189	if (!t) {
1190		fw_notice(card, "unsolicited response (source %x, tlabel %x)\n",
1191			  source, tlabel);
1192		return;
1193	}
1194
1195	/*
1196	 * The response handler may be executed while the request handler
1197	 * is still pending.  Cancel the request handler.
1198	 */
1199	card->driver->cancel_packet(card, &t->packet);
1200
1201	if (!t->with_tstamp) {
1202		t->callback.without_tstamp(card, rcode, data, data_length, t->callback_data);
1203	} else {
1204		t->callback.with_tstamp(card, rcode, t->packet.timestamp, p->timestamp, data,
1205					data_length, t->callback_data);
1206	}
1207}
1208EXPORT_SYMBOL(fw_core_handle_response);
1209
1210/**
1211 * fw_rcode_string - convert a firewire result code to an error description
1212 * @rcode: the result code
1213 */
1214const char *fw_rcode_string(int rcode)
1215{
1216	static const char *const names[] = {
1217		[RCODE_COMPLETE]       = "no error",
1218		[RCODE_CONFLICT_ERROR] = "conflict error",
1219		[RCODE_DATA_ERROR]     = "data error",
1220		[RCODE_TYPE_ERROR]     = "type error",
1221		[RCODE_ADDRESS_ERROR]  = "address error",
1222		[RCODE_SEND_ERROR]     = "send error",
1223		[RCODE_CANCELLED]      = "timeout",
1224		[RCODE_BUSY]           = "busy",
1225		[RCODE_GENERATION]     = "bus reset",
1226		[RCODE_NO_ACK]         = "no ack",
1227	};
1228
1229	if ((unsigned int)rcode < ARRAY_SIZE(names) && names[rcode])
1230		return names[rcode];
1231	else
1232		return "unknown";
1233}
1234EXPORT_SYMBOL(fw_rcode_string);
1235
1236static const struct fw_address_region topology_map_region =
1237	{ .start = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP,
1238	  .end   = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP_END, };
1239
1240static void handle_topology_map(struct fw_card *card, struct fw_request *request,
1241		int tcode, int destination, int source, int generation,
1242		unsigned long long offset, void *payload, size_t length,
1243		void *callback_data)
1244{
1245	int start;
1246
1247	if (!tcode_is_read_request(tcode)) {
1248		fw_send_response(card, request, RCODE_TYPE_ERROR);
1249		return;
1250	}
1251
1252	if ((offset & 3) > 0 || (length & 3) > 0) {
1253		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
1254		return;
1255	}
1256
1257	start = (offset - topology_map_region.start) / 4;
1258
1259	// NOTE: This can be without irqsave when we can guarantee that fw_send_request() for local
1260	// destination never runs in any type of IRQ context.
1261	scoped_guard(spinlock_irqsave, &card->topology_map.lock)
1262		memcpy(payload, &card->topology_map.buffer[start], length);
1263
1264	fw_send_response(card, request, RCODE_COMPLETE);
1265}
1266
1267static struct fw_address_handler topology_map = {
1268	.length			= 0x400,
1269	.address_callback	= handle_topology_map,
1270};
1271
1272static const struct fw_address_region registers_region =
1273	{ .start = CSR_REGISTER_BASE,
1274	  .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM, };
1275
1276static void update_split_timeout(struct fw_card *card)
1277__must_hold(&card->split_timeout.lock)
1278{
1279	unsigned int cycles;
1280
1281	cycles = card->split_timeout.hi * 8000 + (card->split_timeout.lo >> 19);
1282
1283	/* minimum per IEEE 1394, maximum which doesn't overflow OHCI */
1284	cycles = clamp(cycles, 800u, 3u * 8000u);
1285
1286	card->split_timeout.cycles = cycles;
1287	card->split_timeout.jiffies = isoc_cycles_to_jiffies(cycles);
1288}
1289
1290static void handle_registers(struct fw_card *card, struct fw_request *request,
1291		int tcode, int destination, int source, int generation,
1292		unsigned long long offset, void *payload, size_t length,
1293		void *callback_data)
1294{
1295	int reg = offset & ~CSR_REGISTER_BASE;
1296	__be32 *data = payload;
1297	int rcode = RCODE_COMPLETE;
1298
1299	switch (reg) {
1300	case CSR_PRIORITY_BUDGET:
1301		if (!card->priority_budget_implemented) {
1302			rcode = RCODE_ADDRESS_ERROR;
1303			break;
1304		}
1305		fallthrough;
1306
1307	case CSR_NODE_IDS:
1308		/*
1309		 * per IEEE 1394-2008 8.3.22.3, not IEEE 1394.1-2004 3.2.8
1310		 * and 9.6, but interoperable with IEEE 1394.1-2004 bridges
1311		 */
1312		fallthrough;
1313
1314	case CSR_STATE_CLEAR:
1315	case CSR_STATE_SET:
1316	case CSR_CYCLE_TIME:
1317	case CSR_BUS_TIME:
1318	case CSR_BUSY_TIMEOUT:
1319		if (tcode == TCODE_READ_QUADLET_REQUEST)
1320			*data = cpu_to_be32(card->driver->read_csr(card, reg));
1321		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1322			card->driver->write_csr(card, reg, be32_to_cpu(*data));
1323		else
1324			rcode = RCODE_TYPE_ERROR;
1325		break;
1326
1327	case CSR_RESET_START:
1328		if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1329			card->driver->write_csr(card, CSR_STATE_CLEAR,
1330						CSR_STATE_BIT_ABDICATE);
1331		else
1332			rcode = RCODE_TYPE_ERROR;
1333		break;
1334
1335	case CSR_SPLIT_TIMEOUT_HI:
1336		if (tcode == TCODE_READ_QUADLET_REQUEST) {
1337			*data = cpu_to_be32(card->split_timeout.hi);
1338		} else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1339			// NOTE: This can be without irqsave when we can guarantee that
1340			// __fw_send_request() for local destination never runs in any type of IRQ
1341			// context.
1342			scoped_guard(spinlock_irqsave, &card->split_timeout.lock) {
1343				card->split_timeout.hi = be32_to_cpu(*data) & 7;
1344				update_split_timeout(card);
1345			}
1346		} else {
1347			rcode = RCODE_TYPE_ERROR;
1348		}
1349		break;
1350
1351	case CSR_SPLIT_TIMEOUT_LO:
1352		if (tcode == TCODE_READ_QUADLET_REQUEST) {
1353			*data = cpu_to_be32(card->split_timeout.lo);
1354		} else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1355			// NOTE: This can be without irqsave when we can guarantee that
1356			// __fw_send_request() for local destination never runs in any type of IRQ
1357			// context.
1358			scoped_guard(spinlock_irqsave, &card->split_timeout.lock) {
1359				card->split_timeout.lo = be32_to_cpu(*data) & 0xfff80000;
1360				update_split_timeout(card);
1361			}
1362		} else {
1363			rcode = RCODE_TYPE_ERROR;
1364		}
1365		break;
1366
1367	case CSR_MAINT_UTILITY:
1368		if (tcode == TCODE_READ_QUADLET_REQUEST)
1369			*data = card->maint_utility_register;
1370		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1371			card->maint_utility_register = *data;
1372		else
1373			rcode = RCODE_TYPE_ERROR;
1374		break;
1375
1376	case CSR_BROADCAST_CHANNEL:
1377		if (tcode == TCODE_READ_QUADLET_REQUEST)
1378			*data = cpu_to_be32(card->broadcast_channel);
1379		else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1380			card->broadcast_channel =
1381			    (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
1382			    BROADCAST_CHANNEL_INITIAL;
1383		else
1384			rcode = RCODE_TYPE_ERROR;
1385		break;
1386
1387	case CSR_BUS_MANAGER_ID:
1388	case CSR_BANDWIDTH_AVAILABLE:
1389	case CSR_CHANNELS_AVAILABLE_HI:
1390	case CSR_CHANNELS_AVAILABLE_LO:
1391		/*
1392		 * FIXME: these are handled by the OHCI hardware and
1393		 * the stack never sees these request. If we add
1394		 * support for a new type of controller that doesn't
1395		 * handle this in hardware we need to deal with these
1396		 * transactions.
1397		 */
1398		BUG();
1399		break;
1400
1401	default:
1402		rcode = RCODE_ADDRESS_ERROR;
1403		break;
1404	}
1405
1406	fw_send_response(card, request, rcode);
1407}
1408
1409static struct fw_address_handler registers = {
1410	.length			= 0x400,
1411	.address_callback	= handle_registers,
1412};
1413
1414static void handle_low_memory(struct fw_card *card, struct fw_request *request,
1415		int tcode, int destination, int source, int generation,
1416		unsigned long long offset, void *payload, size_t length,
1417		void *callback_data)
1418{
1419	/*
1420	 * This catches requests not handled by the physical DMA unit,
1421	 * i.e., wrong transaction types or unauthorized source nodes.
1422	 */
1423	fw_send_response(card, request, RCODE_TYPE_ERROR);
1424}
1425
1426static struct fw_address_handler low_memory = {
1427	.length			= FW_MAX_PHYSICAL_RANGE,
1428	.address_callback	= handle_low_memory,
1429};
1430
1431MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1432MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
1433MODULE_LICENSE("GPL");
1434
1435static const u32 vendor_textual_descriptor[] = {
1436	/* textual descriptor leaf () */
1437	0x00060000,
1438	0x00000000,
1439	0x00000000,
1440	0x4c696e75,		/* L i n u */
1441	0x78204669,		/* x   F i */
1442	0x72657769,		/* r e w i */
1443	0x72650000,		/* r e     */
1444};
1445
1446static const u32 model_textual_descriptor[] = {
1447	/* model descriptor leaf () */
1448	0x00030000,
1449	0x00000000,
1450	0x00000000,
1451	0x4a756a75,		/* J u j u */
1452};
1453
1454static struct fw_descriptor vendor_id_descriptor = {
1455	.length = ARRAY_SIZE(vendor_textual_descriptor),
1456	.immediate = 0x03001f11,
1457	.key = 0x81000000,
1458	.data = vendor_textual_descriptor,
1459};
1460
1461static struct fw_descriptor model_id_descriptor = {
1462	.length = ARRAY_SIZE(model_textual_descriptor),
1463	.immediate = 0x17023901,
1464	.key = 0x81000000,
1465	.data = model_textual_descriptor,
1466};
1467
1468static int __init fw_core_init(void)
1469{
1470	int ret;
1471
1472	fw_workqueue = alloc_workqueue("firewire", WQ_MEM_RECLAIM | WQ_UNBOUND,
1473				       0);
1474	if (!fw_workqueue)
1475		return -ENOMEM;
1476
1477	ret = bus_register(&fw_bus_type);
1478	if (ret < 0) {
1479		destroy_workqueue(fw_workqueue);
1480		return ret;
1481	}
1482
1483	fw_cdev_major = register_chrdev(0, "firewire", &fw_device_ops);
1484	if (fw_cdev_major < 0) {
1485		bus_unregister(&fw_bus_type);
1486		destroy_workqueue(fw_workqueue);
1487		return fw_cdev_major;
1488	}
1489
1490	fw_core_add_address_handler(&topology_map, &topology_map_region);
1491	fw_core_add_address_handler(&registers, &registers_region);
1492	fw_core_add_address_handler(&low_memory, &low_memory_region);
1493	fw_core_add_descriptor(&vendor_id_descriptor);
1494	fw_core_add_descriptor(&model_id_descriptor);
1495
1496	return 0;
1497}
1498
1499static void __exit fw_core_cleanup(void)
1500{
1501	unregister_chrdev(fw_cdev_major, "firewire");
1502	bus_unregister(&fw_bus_type);
1503	destroy_workqueue(fw_workqueue);
1504	xa_destroy(&fw_device_xa);
1505}
1506
1507module_init(fw_core_init);
1508module_exit(fw_core_cleanup);