GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / firewire / 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/idr.h>
17 #include <linux/jiffies.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 #include <linux/rculist.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 #include <linux/string.h>
25 #include <linux/timer.h>
26 #include <linux/types.h>
27 #include <linux/workqueue.h>
28
29 #include <asm/byteorder.h>
30
31 #include "core.h"
32
33 #define HEADER_PRI(pri)                 ((pri) << 0)
34 #define HEADER_TCODE(tcode)             ((tcode) << 4)
35 #define HEADER_RETRY(retry)             ((retry) << 8)
36 #define HEADER_TLABEL(tlabel)           ((tlabel) << 10)
37 #define HEADER_DESTINATION(destination) ((destination) << 16)
38 #define HEADER_SOURCE(source)           ((source) << 16)
39 #define HEADER_RCODE(rcode)             ((rcode) << 12)
40 #define HEADER_OFFSET_HIGH(offset_high) ((offset_high) << 0)
41 #define HEADER_DATA_LENGTH(length)      ((length) << 16)
42 #define HEADER_EXTENDED_TCODE(tcode)    ((tcode) << 0)
43
44 #define HEADER_GET_TCODE(q)             (((q) >> 4) & 0x0f)
45 #define HEADER_GET_TLABEL(q)            (((q) >> 10) & 0x3f)
46 #define HEADER_GET_RCODE(q)             (((q) >> 12) & 0x0f)
47 #define HEADER_GET_DESTINATION(q)       (((q) >> 16) & 0xffff)
48 #define HEADER_GET_SOURCE(q)            (((q) >> 16) & 0xffff)
49 #define HEADER_GET_OFFSET_HIGH(q)       (((q) >> 0) & 0xffff)
50 #define HEADER_GET_DATA_LENGTH(q)       (((q) >> 16) & 0xffff)
51 #define HEADER_GET_EXTENDED_TCODE(q)    (((q) >> 0) & 0xffff)
52
53 #define HEADER_DESTINATION_IS_BROADCAST(q) \
54         (((q) & HEADER_DESTINATION(0x3f)) == HEADER_DESTINATION(0x3f))
55
56 #define PHY_PACKET_CONFIG       0x0
57 #define PHY_PACKET_LINK_ON      0x1
58 #define PHY_PACKET_SELF_ID      0x2
59
60 #define PHY_CONFIG_GAP_COUNT(gap_count) (((gap_count) << 16) | (1 << 22))
61 #define PHY_CONFIG_ROOT_ID(node_id)     ((((node_id) & 0x3f) << 24) | (1 << 23))
62 #define PHY_IDENTIFIER(id)              ((id) << 30)
63
64 /* returns 0 if the split timeout handler is already running */
65 static int try_cancel_split_timeout(struct fw_transaction *t)
66 {
67         if (t->is_split_transaction)
68                 return del_timer(&t->split_timeout_timer);
69         else
70                 return 1;
71 }
72
73 static int close_transaction(struct fw_transaction *transaction,
74                              struct fw_card *card, int rcode)
75 {
76         struct fw_transaction *t = NULL, *iter;
77         unsigned long flags;
78
79         spin_lock_irqsave(&card->lock, flags);
80         list_for_each_entry(iter, &card->transaction_list, link) {
81                 if (iter == transaction) {
82                         if (!try_cancel_split_timeout(iter)) {
83                                 spin_unlock_irqrestore(&card->lock, flags);
84                                 goto timed_out;
85                         }
86                         list_del_init(&iter->link);
87                         card->tlabel_mask &= ~(1ULL << iter->tlabel);
88                         t = iter;
89                         break;
90                 }
91         }
92         spin_unlock_irqrestore(&card->lock, flags);
93
94         if (t) {
95                 t->callback(card, rcode, NULL, 0, t->callback_data);
96                 return 0;
97         }
98
99  timed_out:
100         return -ENOENT;
101 }
102
103 /*
104  * Only valid for transactions that are potentially pending (ie have
105  * been sent).
106  */
107 int fw_cancel_transaction(struct fw_card *card,
108                           struct fw_transaction *transaction)
109 {
110         /*
111          * Cancel the packet transmission if it's still queued.  That
112          * will call the packet transmission callback which cancels
113          * the transaction.
114          */
115
116         if (card->driver->cancel_packet(card, &transaction->packet) == 0)
117                 return 0;
118
119         /*
120          * If the request packet has already been sent, we need to see
121          * if the transaction is still pending and remove it in that case.
122          */
123
124         return close_transaction(transaction, card, RCODE_CANCELLED);
125 }
126 EXPORT_SYMBOL(fw_cancel_transaction);
127
128 static void split_transaction_timeout_callback(struct timer_list *timer)
129 {
130         struct fw_transaction *t = from_timer(t, timer, split_timeout_timer);
131         struct fw_card *card = t->card;
132         unsigned long flags;
133
134         spin_lock_irqsave(&card->lock, flags);
135         if (list_empty(&t->link)) {
136                 spin_unlock_irqrestore(&card->lock, flags);
137                 return;
138         }
139         list_del(&t->link);
140         card->tlabel_mask &= ~(1ULL << t->tlabel);
141         spin_unlock_irqrestore(&card->lock, flags);
142
143         t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
144 }
145
146 static void start_split_transaction_timeout(struct fw_transaction *t,
147                                             struct fw_card *card)
148 {
149         unsigned long flags;
150
151         spin_lock_irqsave(&card->lock, flags);
152
153         if (list_empty(&t->link) || WARN_ON(t->is_split_transaction)) {
154                 spin_unlock_irqrestore(&card->lock, flags);
155                 return;
156         }
157
158         t->is_split_transaction = true;
159         mod_timer(&t->split_timeout_timer,
160                   jiffies + card->split_timeout_jiffies);
161
162         spin_unlock_irqrestore(&card->lock, flags);
163 }
164
165 static void transmit_complete_callback(struct fw_packet *packet,
166                                        struct fw_card *card, int status)
167 {
168         struct fw_transaction *t =
169             container_of(packet, struct fw_transaction, packet);
170
171         switch (status) {
172         case ACK_COMPLETE:
173                 close_transaction(t, card, RCODE_COMPLETE);
174                 break;
175         case ACK_PENDING:
176                 start_split_transaction_timeout(t, card);
177                 break;
178         case ACK_BUSY_X:
179         case ACK_BUSY_A:
180         case ACK_BUSY_B:
181                 close_transaction(t, card, RCODE_BUSY);
182                 break;
183         case ACK_DATA_ERROR:
184                 close_transaction(t, card, RCODE_DATA_ERROR);
185                 break;
186         case ACK_TYPE_ERROR:
187                 close_transaction(t, card, RCODE_TYPE_ERROR);
188                 break;
189         default:
190                 /*
191                  * In this case the ack is really a juju specific
192                  * rcode, so just forward that to the callback.
193                  */
194                 close_transaction(t, card, status);
195                 break;
196         }
197 }
198
199 static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
200                 int destination_id, int source_id, int generation, int speed,
201                 unsigned long long offset, void *payload, size_t length)
202 {
203         int ext_tcode;
204
205         if (tcode == TCODE_STREAM_DATA) {
206                 packet->header[0] =
207                         HEADER_DATA_LENGTH(length) |
208                         destination_id |
209                         HEADER_TCODE(TCODE_STREAM_DATA);
210                 packet->header_length = 4;
211                 packet->payload = payload;
212                 packet->payload_length = length;
213
214                 goto common;
215         }
216
217         if (tcode > 0x10) {
218                 ext_tcode = tcode & ~0x10;
219                 tcode = TCODE_LOCK_REQUEST;
220         } else
221                 ext_tcode = 0;
222
223         packet->header[0] =
224                 HEADER_RETRY(RETRY_X) |
225                 HEADER_TLABEL(tlabel) |
226                 HEADER_TCODE(tcode) |
227                 HEADER_DESTINATION(destination_id);
228         packet->header[1] =
229                 HEADER_OFFSET_HIGH(offset >> 32) | HEADER_SOURCE(source_id);
230         packet->header[2] =
231                 offset;
232
233         switch (tcode) {
234         case TCODE_WRITE_QUADLET_REQUEST:
235                 packet->header[3] = *(u32 *)payload;
236                 packet->header_length = 16;
237                 packet->payload_length = 0;
238                 break;
239
240         case TCODE_LOCK_REQUEST:
241         case TCODE_WRITE_BLOCK_REQUEST:
242                 packet->header[3] =
243                         HEADER_DATA_LENGTH(length) |
244                         HEADER_EXTENDED_TCODE(ext_tcode);
245                 packet->header_length = 16;
246                 packet->payload = payload;
247                 packet->payload_length = length;
248                 break;
249
250         case TCODE_READ_QUADLET_REQUEST:
251                 packet->header_length = 12;
252                 packet->payload_length = 0;
253                 break;
254
255         case TCODE_READ_BLOCK_REQUEST:
256                 packet->header[3] =
257                         HEADER_DATA_LENGTH(length) |
258                         HEADER_EXTENDED_TCODE(ext_tcode);
259                 packet->header_length = 16;
260                 packet->payload_length = 0;
261                 break;
262
263         default:
264                 WARN(1, "wrong tcode %d\n", tcode);
265         }
266  common:
267         packet->speed = speed;
268         packet->generation = generation;
269         packet->ack = 0;
270         packet->payload_mapped = false;
271 }
272
273 static int allocate_tlabel(struct fw_card *card)
274 {
275         int tlabel;
276
277         tlabel = card->current_tlabel;
278         while (card->tlabel_mask & (1ULL << tlabel)) {
279                 tlabel = (tlabel + 1) & 0x3f;
280                 if (tlabel == card->current_tlabel)
281                         return -EBUSY;
282         }
283
284         card->current_tlabel = (tlabel + 1) & 0x3f;
285         card->tlabel_mask |= 1ULL << tlabel;
286
287         return tlabel;
288 }
289
290 /**
291  * fw_send_request() - submit a request packet for transmission
292  * @card:               interface to send the request at
293  * @t:                  transaction instance to which the request belongs
294  * @tcode:              transaction code
295  * @destination_id:     destination node ID, consisting of bus_ID and phy_ID
296  * @generation:         bus generation in which request and response are valid
297  * @speed:              transmission speed
298  * @offset:             48bit wide offset into destination's address space
299  * @payload:            data payload for the request subaction
300  * @length:             length of the payload, in bytes
301  * @callback:           function to be called when the transaction is completed
302  * @callback_data:      data to be passed to the transaction completion callback
303  *
304  * Submit a request packet into the asynchronous request transmission queue.
305  * Can be called from atomic context.  If you prefer a blocking API, use
306  * fw_run_transaction() in a context that can sleep.
307  *
308  * In case of lock requests, specify one of the firewire-core specific %TCODE_
309  * constants instead of %TCODE_LOCK_REQUEST in @tcode.
310  *
311  * Make sure that the value in @destination_id is not older than the one in
312  * @generation.  Otherwise the request is in danger to be sent to a wrong node.
313  *
314  * In case of asynchronous stream packets i.e. %TCODE_STREAM_DATA, the caller
315  * needs to synthesize @destination_id with fw_stream_packet_destination_id().
316  * It will contain tag, channel, and sy data instead of a node ID then.
317  *
318  * The payload buffer at @data is going to be DMA-mapped except in case of
319  * @length <= 8 or of local (loopback) requests.  Hence make sure that the
320  * buffer complies with the restrictions of the streaming DMA mapping API.
321  * @payload must not be freed before the @callback is called.
322  *
323  * In case of request types without payload, @data is NULL and @length is 0.
324  *
325  * After the transaction is completed successfully or unsuccessfully, the
326  * @callback will be called.  Among its parameters is the response code which
327  * is either one of the rcodes per IEEE 1394 or, in case of internal errors,
328  * the firewire-core specific %RCODE_SEND_ERROR.  The other firewire-core
329  * specific rcodes (%RCODE_CANCELLED, %RCODE_BUSY, %RCODE_GENERATION,
330  * %RCODE_NO_ACK) denote transaction timeout, busy responder, stale request
331  * generation, or missing ACK respectively.
332  *
333  * Note some timing corner cases:  fw_send_request() may complete much earlier
334  * than when the request packet actually hits the wire.  On the other hand,
335  * transaction completion and hence execution of @callback may happen even
336  * before fw_send_request() returns.
337  */
338 void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
339                      int destination_id, int generation, int speed,
340                      unsigned long long offset, void *payload, size_t length,
341                      fw_transaction_callback_t callback, void *callback_data)
342 {
343         unsigned long flags;
344         int tlabel;
345
346         /*
347          * Allocate tlabel from the bitmap and put the transaction on
348          * the list while holding the card spinlock.
349          */
350
351         spin_lock_irqsave(&card->lock, flags);
352
353         tlabel = allocate_tlabel(card);
354         if (tlabel < 0) {
355                 spin_unlock_irqrestore(&card->lock, flags);
356                 callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
357                 return;
358         }
359
360         t->node_id = destination_id;
361         t->tlabel = tlabel;
362         t->card = card;
363         t->is_split_transaction = false;
364         timer_setup(&t->split_timeout_timer,
365                     split_transaction_timeout_callback, 0);
366         t->callback = callback;
367         t->callback_data = callback_data;
368
369         fw_fill_request(&t->packet, tcode, t->tlabel,
370                         destination_id, card->node_id, generation,
371                         speed, offset, payload, length);
372         t->packet.callback = transmit_complete_callback;
373
374         list_add_tail(&t->link, &card->transaction_list);
375
376         spin_unlock_irqrestore(&card->lock, flags);
377
378         card->driver->send_request(card, &t->packet);
379 }
380 EXPORT_SYMBOL(fw_send_request);
381
382 struct transaction_callback_data {
383         struct completion done;
384         void *payload;
385         int rcode;
386 };
387
388 static void transaction_callback(struct fw_card *card, int rcode,
389                                  void *payload, size_t length, void *data)
390 {
391         struct transaction_callback_data *d = data;
392
393         if (rcode == RCODE_COMPLETE)
394                 memcpy(d->payload, payload, length);
395         d->rcode = rcode;
396         complete(&d->done);
397 }
398
399 /**
400  * fw_run_transaction() - send request and sleep until transaction is completed
401  * @card:               card interface for this request
402  * @tcode:              transaction code
403  * @destination_id:     destination node ID, consisting of bus_ID and phy_ID
404  * @generation:         bus generation in which request and response are valid
405  * @speed:              transmission speed
406  * @offset:             48bit wide offset into destination's address space
407  * @payload:            data payload for the request subaction
408  * @length:             length of the payload, in bytes
409  *
410  * Returns the RCODE.  See fw_send_request() for parameter documentation.
411  * Unlike fw_send_request(), @data points to the payload of the request or/and
412  * to the payload of the response.  DMA mapping restrictions apply to outbound
413  * request payloads of >= 8 bytes but not to inbound response payloads.
414  */
415 int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
416                        int generation, int speed, unsigned long long offset,
417                        void *payload, size_t length)
418 {
419         struct transaction_callback_data d;
420         struct fw_transaction t;
421
422         timer_setup_on_stack(&t.split_timeout_timer, NULL, 0);
423         init_completion(&d.done);
424         d.payload = payload;
425         fw_send_request(card, &t, tcode, destination_id, generation, speed,
426                         offset, payload, length, transaction_callback, &d);
427         wait_for_completion(&d.done);
428         destroy_timer_on_stack(&t.split_timeout_timer);
429
430         return d.rcode;
431 }
432 EXPORT_SYMBOL(fw_run_transaction);
433
434 static DEFINE_MUTEX(phy_config_mutex);
435 static DECLARE_COMPLETION(phy_config_done);
436
437 static void transmit_phy_packet_callback(struct fw_packet *packet,
438                                          struct fw_card *card, int status)
439 {
440         complete(&phy_config_done);
441 }
442
443 static struct fw_packet phy_config_packet = {
444         .header_length  = 12,
445         .header[0]      = TCODE_LINK_INTERNAL << 4,
446         .payload_length = 0,
447         .speed          = SCODE_100,
448         .callback       = transmit_phy_packet_callback,
449 };
450
451 void fw_send_phy_config(struct fw_card *card,
452                         int node_id, int generation, int gap_count)
453 {
454         long timeout = DIV_ROUND_UP(HZ, 10);
455         u32 data = PHY_IDENTIFIER(PHY_PACKET_CONFIG);
456
457         if (node_id != FW_PHY_CONFIG_NO_NODE_ID)
458                 data |= PHY_CONFIG_ROOT_ID(node_id);
459
460         if (gap_count == FW_PHY_CONFIG_CURRENT_GAP_COUNT) {
461                 gap_count = card->driver->read_phy_reg(card, 1);
462                 if (gap_count < 0)
463                         return;
464
465                 gap_count &= 63;
466                 if (gap_count == 63)
467                         return;
468         }
469         data |= PHY_CONFIG_GAP_COUNT(gap_count);
470
471         mutex_lock(&phy_config_mutex);
472
473         phy_config_packet.header[1] = data;
474         phy_config_packet.header[2] = ~data;
475         phy_config_packet.generation = generation;
476         reinit_completion(&phy_config_done);
477
478         card->driver->send_request(card, &phy_config_packet);
479         wait_for_completion_timeout(&phy_config_done, timeout);
480
481         mutex_unlock(&phy_config_mutex);
482 }
483
484 static struct fw_address_handler *lookup_overlapping_address_handler(
485         struct list_head *list, unsigned long long offset, size_t length)
486 {
487         struct fw_address_handler *handler;
488
489         list_for_each_entry_rcu(handler, list, link) {
490                 if (handler->offset < offset + length &&
491                     offset < handler->offset + handler->length)
492                         return handler;
493         }
494
495         return NULL;
496 }
497
498 static bool is_enclosing_handler(struct fw_address_handler *handler,
499                                  unsigned long long offset, size_t length)
500 {
501         return handler->offset <= offset &&
502                 offset + length <= handler->offset + handler->length;
503 }
504
505 static struct fw_address_handler *lookup_enclosing_address_handler(
506         struct list_head *list, unsigned long long offset, size_t length)
507 {
508         struct fw_address_handler *handler;
509
510         list_for_each_entry_rcu(handler, list, link) {
511                 if (is_enclosing_handler(handler, offset, length))
512                         return handler;
513         }
514
515         return NULL;
516 }
517
518 static DEFINE_SPINLOCK(address_handler_list_lock);
519 static LIST_HEAD(address_handler_list);
520
521 const struct fw_address_region fw_high_memory_region =
522         { .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
523 EXPORT_SYMBOL(fw_high_memory_region);
524
525 static const struct fw_address_region low_memory_region =
526         { .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
527
528 #if 0
529 const struct fw_address_region fw_private_region =
530         { .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
531 const struct fw_address_region fw_csr_region =
532         { .start = CSR_REGISTER_BASE,
533           .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM_END,  };
534 const struct fw_address_region fw_unit_space_region =
535         { .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
536 #endif  /*  0  */
537
538 static bool is_in_fcp_region(u64 offset, size_t length)
539 {
540         return offset >= (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
541                 offset + length <= (CSR_REGISTER_BASE | CSR_FCP_END);
542 }
543
544 /**
545  * fw_core_add_address_handler() - register for incoming requests
546  * @handler:    callback
547  * @region:     region in the IEEE 1212 node space address range
548  *
549  * region->start, ->end, and handler->length have to be quadlet-aligned.
550  *
551  * When a request is received that falls within the specified address range,
552  * the specified callback is invoked.  The parameters passed to the callback
553  * give the details of the particular request.
554  *
555  * To be called in process context.
556  * Return value:  0 on success, non-zero otherwise.
557  *
558  * The start offset of the handler's address region is determined by
559  * fw_core_add_address_handler() and is returned in handler->offset.
560  *
561  * Address allocations are exclusive, except for the FCP registers.
562  */
563 int fw_core_add_address_handler(struct fw_address_handler *handler,
564                                 const struct fw_address_region *region)
565 {
566         struct fw_address_handler *other;
567         int ret = -EBUSY;
568
569         if (region->start & 0xffff000000000003ULL ||
570             region->start >= region->end ||
571             region->end   > 0x0001000000000000ULL ||
572             handler->length & 3 ||
573             handler->length == 0)
574                 return -EINVAL;
575
576         spin_lock(&address_handler_list_lock);
577
578         handler->offset = region->start;
579         while (handler->offset + handler->length <= region->end) {
580                 if (is_in_fcp_region(handler->offset, handler->length))
581                         other = NULL;
582                 else
583                         other = lookup_overlapping_address_handler
584                                         (&address_handler_list,
585                                          handler->offset, handler->length);
586                 if (other != NULL) {
587                         handler->offset += other->length;
588                 } else {
589                         list_add_tail_rcu(&handler->link, &address_handler_list);
590                         ret = 0;
591                         break;
592                 }
593         }
594
595         spin_unlock(&address_handler_list_lock);
596
597         return ret;
598 }
599 EXPORT_SYMBOL(fw_core_add_address_handler);
600
601 /**
602  * fw_core_remove_address_handler() - unregister an address handler
603  * @handler: callback
604  *
605  * To be called in process context.
606  *
607  * When fw_core_remove_address_handler() returns, @handler->callback() is
608  * guaranteed to not run on any CPU anymore.
609  */
610 void fw_core_remove_address_handler(struct fw_address_handler *handler)
611 {
612         spin_lock(&address_handler_list_lock);
613         list_del_rcu(&handler->link);
614         spin_unlock(&address_handler_list_lock);
615         synchronize_rcu();
616 }
617 EXPORT_SYMBOL(fw_core_remove_address_handler);
618
619 struct fw_request {
620         struct fw_packet response;
621         u32 request_header[4];
622         int ack;
623         u32 timestamp;
624         u32 length;
625         u32 data[];
626 };
627
628 static void free_response_callback(struct fw_packet *packet,
629                                    struct fw_card *card, int status)
630 {
631         struct fw_request *request;
632
633         request = container_of(packet, struct fw_request, response);
634         kfree(request);
635 }
636
637 int fw_get_response_length(struct fw_request *r)
638 {
639         int tcode, ext_tcode, data_length;
640
641         tcode = HEADER_GET_TCODE(r->request_header[0]);
642
643         switch (tcode) {
644         case TCODE_WRITE_QUADLET_REQUEST:
645         case TCODE_WRITE_BLOCK_REQUEST:
646                 return 0;
647
648         case TCODE_READ_QUADLET_REQUEST:
649                 return 4;
650
651         case TCODE_READ_BLOCK_REQUEST:
652                 data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
653                 return data_length;
654
655         case TCODE_LOCK_REQUEST:
656                 ext_tcode = HEADER_GET_EXTENDED_TCODE(r->request_header[3]);
657                 data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
658                 switch (ext_tcode) {
659                 case EXTCODE_FETCH_ADD:
660                 case EXTCODE_LITTLE_ADD:
661                         return data_length;
662                 default:
663                         return data_length / 2;
664                 }
665
666         default:
667                 WARN(1, "wrong tcode %d\n", tcode);
668                 return 0;
669         }
670 }
671
672 void fw_fill_response(struct fw_packet *response, u32 *request_header,
673                       int rcode, void *payload, size_t length)
674 {
675         int tcode, tlabel, extended_tcode, source, destination;
676
677         tcode          = HEADER_GET_TCODE(request_header[0]);
678         tlabel         = HEADER_GET_TLABEL(request_header[0]);
679         source         = HEADER_GET_DESTINATION(request_header[0]);
680         destination    = HEADER_GET_SOURCE(request_header[1]);
681         extended_tcode = HEADER_GET_EXTENDED_TCODE(request_header[3]);
682
683         response->header[0] =
684                 HEADER_RETRY(RETRY_1) |
685                 HEADER_TLABEL(tlabel) |
686                 HEADER_DESTINATION(destination);
687         response->header[1] =
688                 HEADER_SOURCE(source) |
689                 HEADER_RCODE(rcode);
690         response->header[2] = 0;
691
692         switch (tcode) {
693         case TCODE_WRITE_QUADLET_REQUEST:
694         case TCODE_WRITE_BLOCK_REQUEST:
695                 response->header[0] |= HEADER_TCODE(TCODE_WRITE_RESPONSE);
696                 response->header_length = 12;
697                 response->payload_length = 0;
698                 break;
699
700         case TCODE_READ_QUADLET_REQUEST:
701                 response->header[0] |=
702                         HEADER_TCODE(TCODE_READ_QUADLET_RESPONSE);
703                 if (payload != NULL)
704                         response->header[3] = *(u32 *)payload;
705                 else
706                         response->header[3] = 0;
707                 response->header_length = 16;
708                 response->payload_length = 0;
709                 break;
710
711         case TCODE_READ_BLOCK_REQUEST:
712         case TCODE_LOCK_REQUEST:
713                 response->header[0] |= HEADER_TCODE(tcode + 2);
714                 response->header[3] =
715                         HEADER_DATA_LENGTH(length) |
716                         HEADER_EXTENDED_TCODE(extended_tcode);
717                 response->header_length = 16;
718                 response->payload = payload;
719                 response->payload_length = length;
720                 break;
721
722         default:
723                 WARN(1, "wrong tcode %d\n", tcode);
724         }
725
726         response->payload_mapped = false;
727 }
728 EXPORT_SYMBOL(fw_fill_response);
729
730 static u32 compute_split_timeout_timestamp(struct fw_card *card,
731                                            u32 request_timestamp)
732 {
733         unsigned int cycles;
734         u32 timestamp;
735
736         cycles = card->split_timeout_cycles;
737         cycles += request_timestamp & 0x1fff;
738
739         timestamp = request_timestamp & ~0x1fff;
740         timestamp += (cycles / 8000) << 13;
741         timestamp |= cycles % 8000;
742
743         return timestamp;
744 }
745
746 static struct fw_request *allocate_request(struct fw_card *card,
747                                            struct fw_packet *p)
748 {
749         struct fw_request *request;
750         u32 *data, length;
751         int request_tcode;
752
753         request_tcode = HEADER_GET_TCODE(p->header[0]);
754         switch (request_tcode) {
755         case TCODE_WRITE_QUADLET_REQUEST:
756                 data = &p->header[3];
757                 length = 4;
758                 break;
759
760         case TCODE_WRITE_BLOCK_REQUEST:
761         case TCODE_LOCK_REQUEST:
762                 data = p->payload;
763                 length = HEADER_GET_DATA_LENGTH(p->header[3]);
764                 break;
765
766         case TCODE_READ_QUADLET_REQUEST:
767                 data = NULL;
768                 length = 4;
769                 break;
770
771         case TCODE_READ_BLOCK_REQUEST:
772                 data = NULL;
773                 length = HEADER_GET_DATA_LENGTH(p->header[3]);
774                 break;
775
776         default:
777                 fw_notice(card, "ERROR - corrupt request received - %08x %08x %08x\n",
778                          p->header[0], p->header[1], p->header[2]);
779                 return NULL;
780         }
781
782         request = kmalloc(sizeof(*request) + length, GFP_ATOMIC);
783         if (request == NULL)
784                 return NULL;
785
786         request->response.speed = p->speed;
787         request->response.timestamp =
788                         compute_split_timeout_timestamp(card, p->timestamp);
789         request->response.generation = p->generation;
790         request->response.ack = 0;
791         request->response.callback = free_response_callback;
792         request->ack = p->ack;
793         request->timestamp = p->timestamp;
794         request->length = length;
795         if (data)
796                 memcpy(request->data, data, length);
797
798         memcpy(request->request_header, p->header, sizeof(p->header));
799
800         return request;
801 }
802
803 void fw_send_response(struct fw_card *card,
804                       struct fw_request *request, int rcode)
805 {
806         if (WARN_ONCE(!request, "invalid for FCP address handlers"))
807                 return;
808
809         /* unified transaction or broadcast transaction: don't respond */
810         if (request->ack != ACK_PENDING ||
811             HEADER_DESTINATION_IS_BROADCAST(request->request_header[0])) {
812                 kfree(request);
813                 return;
814         }
815
816         if (rcode == RCODE_COMPLETE)
817                 fw_fill_response(&request->response, request->request_header,
818                                  rcode, request->data,
819                                  fw_get_response_length(request));
820         else
821                 fw_fill_response(&request->response, request->request_header,
822                                  rcode, NULL, 0);
823
824         card->driver->send_response(card, &request->response);
825 }
826 EXPORT_SYMBOL(fw_send_response);
827
828 /**
829  * fw_get_request_speed() - returns speed at which the @request was received
830  * @request: firewire request data
831  */
832 int fw_get_request_speed(struct fw_request *request)
833 {
834         return request->response.speed;
835 }
836 EXPORT_SYMBOL(fw_get_request_speed);
837
838 /**
839  * fw_request_get_timestamp: Get timestamp of the request.
840  * @request: The opaque pointer to request structure.
841  *
842  * Get timestamp when 1394 OHCI controller receives the asynchronous request subaction. The
843  * timestamp consists of the low order 3 bits of second field and the full 13 bits of count
844  * field of isochronous cycle time register.
845  *
846  * Returns: timestamp of the request.
847  */
848 u32 fw_request_get_timestamp(const struct fw_request *request)
849 {
850         return request->timestamp;
851 }
852 EXPORT_SYMBOL_GPL(fw_request_get_timestamp);
853
854 static void handle_exclusive_region_request(struct fw_card *card,
855                                             struct fw_packet *p,
856                                             struct fw_request *request,
857                                             unsigned long long offset)
858 {
859         struct fw_address_handler *handler;
860         int tcode, destination, source;
861
862         destination = HEADER_GET_DESTINATION(p->header[0]);
863         source      = HEADER_GET_SOURCE(p->header[1]);
864         tcode       = HEADER_GET_TCODE(p->header[0]);
865         if (tcode == TCODE_LOCK_REQUEST)
866                 tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);
867
868         rcu_read_lock();
869         handler = lookup_enclosing_address_handler(&address_handler_list,
870                                                    offset, request->length);
871         if (handler)
872                 handler->address_callback(card, request,
873                                           tcode, destination, source,
874                                           p->generation, offset,
875                                           request->data, request->length,
876                                           handler->callback_data);
877         rcu_read_unlock();
878
879         if (!handler)
880                 fw_send_response(card, request, RCODE_ADDRESS_ERROR);
881 }
882
883 static void handle_fcp_region_request(struct fw_card *card,
884                                       struct fw_packet *p,
885                                       struct fw_request *request,
886                                       unsigned long long offset)
887 {
888         struct fw_address_handler *handler;
889         int tcode, destination, source;
890
891         if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
892              offset != (CSR_REGISTER_BASE | CSR_FCP_RESPONSE)) ||
893             request->length > 0x200) {
894                 fw_send_response(card, request, RCODE_ADDRESS_ERROR);
895
896                 return;
897         }
898
899         tcode       = HEADER_GET_TCODE(p->header[0]);
900         destination = HEADER_GET_DESTINATION(p->header[0]);
901         source      = HEADER_GET_SOURCE(p->header[1]);
902
903         if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
904             tcode != TCODE_WRITE_BLOCK_REQUEST) {
905                 fw_send_response(card, request, RCODE_TYPE_ERROR);
906
907                 return;
908         }
909
910         rcu_read_lock();
911         list_for_each_entry_rcu(handler, &address_handler_list, link) {
912                 if (is_enclosing_handler(handler, offset, request->length))
913                         handler->address_callback(card, NULL, tcode,
914                                                   destination, source,
915                                                   p->generation, offset,
916                                                   request->data,
917                                                   request->length,
918                                                   handler->callback_data);
919         }
920         rcu_read_unlock();
921
922         fw_send_response(card, request, RCODE_COMPLETE);
923 }
924
925 void fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
926 {
927         struct fw_request *request;
928         unsigned long long offset;
929
930         if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
931                 return;
932
933         if (TCODE_IS_LINK_INTERNAL(HEADER_GET_TCODE(p->header[0]))) {
934                 fw_cdev_handle_phy_packet(card, p);
935                 return;
936         }
937
938         request = allocate_request(card, p);
939         if (request == NULL) {
940                 /* FIXME: send statically allocated busy packet. */
941                 return;
942         }
943
944         offset = ((u64)HEADER_GET_OFFSET_HIGH(p->header[1]) << 32) |
945                 p->header[2];
946
947         if (!is_in_fcp_region(offset, request->length))
948                 handle_exclusive_region_request(card, p, request, offset);
949         else
950                 handle_fcp_region_request(card, p, request, offset);
951
952 }
953 EXPORT_SYMBOL(fw_core_handle_request);
954
955 void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
956 {
957         struct fw_transaction *t = NULL, *iter;
958         unsigned long flags;
959         u32 *data;
960         size_t data_length;
961         int tcode, tlabel, source, rcode;
962
963         tcode   = HEADER_GET_TCODE(p->header[0]);
964         tlabel  = HEADER_GET_TLABEL(p->header[0]);
965         source  = HEADER_GET_SOURCE(p->header[1]);
966         rcode   = HEADER_GET_RCODE(p->header[1]);
967
968         spin_lock_irqsave(&card->lock, flags);
969         list_for_each_entry(iter, &card->transaction_list, link) {
970                 if (iter->node_id == source && iter->tlabel == tlabel) {
971                         if (!try_cancel_split_timeout(iter)) {
972                                 spin_unlock_irqrestore(&card->lock, flags);
973                                 goto timed_out;
974                         }
975                         list_del_init(&iter->link);
976                         card->tlabel_mask &= ~(1ULL << iter->tlabel);
977                         t = iter;
978                         break;
979                 }
980         }
981         spin_unlock_irqrestore(&card->lock, flags);
982
983         if (!t) {
984  timed_out:
985                 fw_notice(card, "unsolicited response (source %x, tlabel %x)\n",
986                           source, tlabel);
987                 return;
988         }
989
990         /*
991          * FIXME: sanity check packet, is length correct, does tcodes
992          * and addresses match.
993          */
994
995         switch (tcode) {
996         case TCODE_READ_QUADLET_RESPONSE:
997                 data = (u32 *) &p->header[3];
998                 data_length = 4;
999                 break;
1000
1001         case TCODE_WRITE_RESPONSE:
1002                 data = NULL;
1003                 data_length = 0;
1004                 break;
1005
1006         case TCODE_READ_BLOCK_RESPONSE:
1007         case TCODE_LOCK_RESPONSE:
1008                 data = p->payload;
1009                 data_length = HEADER_GET_DATA_LENGTH(p->header[3]);
1010                 break;
1011
1012         default:
1013                 /* Should never happen, this is just to shut up gcc. */
1014                 data = NULL;
1015                 data_length = 0;
1016                 break;
1017         }
1018
1019         /*
1020          * The response handler may be executed while the request handler
1021          * is still pending.  Cancel the request handler.
1022          */
1023         card->driver->cancel_packet(card, &t->packet);
1024
1025         t->callback(card, rcode, data, data_length, t->callback_data);
1026 }
1027 EXPORT_SYMBOL(fw_core_handle_response);
1028
1029 /**
1030  * fw_rcode_string - convert a firewire result code to an error description
1031  * @rcode: the result code
1032  */
1033 const char *fw_rcode_string(int rcode)
1034 {
1035         static const char *const names[] = {
1036                 [RCODE_COMPLETE]       = "no error",
1037                 [RCODE_CONFLICT_ERROR] = "conflict error",
1038                 [RCODE_DATA_ERROR]     = "data error",
1039                 [RCODE_TYPE_ERROR]     = "type error",
1040                 [RCODE_ADDRESS_ERROR]  = "address error",
1041                 [RCODE_SEND_ERROR]     = "send error",
1042                 [RCODE_CANCELLED]      = "timeout",
1043                 [RCODE_BUSY]           = "busy",
1044                 [RCODE_GENERATION]     = "bus reset",
1045                 [RCODE_NO_ACK]         = "no ack",
1046         };
1047
1048         if ((unsigned int)rcode < ARRAY_SIZE(names) && names[rcode])
1049                 return names[rcode];
1050         else
1051                 return "unknown";
1052 }
1053 EXPORT_SYMBOL(fw_rcode_string);
1054
1055 static const struct fw_address_region topology_map_region =
1056         { .start = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP,
1057           .end   = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP_END, };
1058
1059 static void handle_topology_map(struct fw_card *card, struct fw_request *request,
1060                 int tcode, int destination, int source, int generation,
1061                 unsigned long long offset, void *payload, size_t length,
1062                 void *callback_data)
1063 {
1064         int start;
1065
1066         if (!TCODE_IS_READ_REQUEST(tcode)) {
1067                 fw_send_response(card, request, RCODE_TYPE_ERROR);
1068                 return;
1069         }
1070
1071         if ((offset & 3) > 0 || (length & 3) > 0) {
1072                 fw_send_response(card, request, RCODE_ADDRESS_ERROR);
1073                 return;
1074         }
1075
1076         start = (offset - topology_map_region.start) / 4;
1077         memcpy(payload, &card->topology_map[start], length);
1078
1079         fw_send_response(card, request, RCODE_COMPLETE);
1080 }
1081
1082 static struct fw_address_handler topology_map = {
1083         .length                 = 0x400,
1084         .address_callback       = handle_topology_map,
1085 };
1086
1087 static const struct fw_address_region registers_region =
1088         { .start = CSR_REGISTER_BASE,
1089           .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM, };
1090
1091 static void update_split_timeout(struct fw_card *card)
1092 {
1093         unsigned int cycles;
1094
1095         cycles = card->split_timeout_hi * 8000 + (card->split_timeout_lo >> 19);
1096
1097         /* minimum per IEEE 1394, maximum which doesn't overflow OHCI */
1098         cycles = clamp(cycles, 800u, 3u * 8000u);
1099
1100         card->split_timeout_cycles = cycles;
1101         card->split_timeout_jiffies = DIV_ROUND_UP(cycles * HZ, 8000);
1102 }
1103
1104 static void handle_registers(struct fw_card *card, struct fw_request *request,
1105                 int tcode, int destination, int source, int generation,
1106                 unsigned long long offset, void *payload, size_t length,
1107                 void *callback_data)
1108 {
1109         int reg = offset & ~CSR_REGISTER_BASE;
1110         __be32 *data = payload;
1111         int rcode = RCODE_COMPLETE;
1112         unsigned long flags;
1113
1114         switch (reg) {
1115         case CSR_PRIORITY_BUDGET:
1116                 if (!card->priority_budget_implemented) {
1117                         rcode = RCODE_ADDRESS_ERROR;
1118                         break;
1119                 }
1120                 fallthrough;
1121
1122         case CSR_NODE_IDS:
1123                 /*
1124                  * per IEEE 1394-2008 8.3.22.3, not IEEE 1394.1-2004 3.2.8
1125                  * and 9.6, but interoperable with IEEE 1394.1-2004 bridges
1126                  */
1127                 fallthrough;
1128
1129         case CSR_STATE_CLEAR:
1130         case CSR_STATE_SET:
1131         case CSR_CYCLE_TIME:
1132         case CSR_BUS_TIME:
1133         case CSR_BUSY_TIMEOUT:
1134                 if (tcode == TCODE_READ_QUADLET_REQUEST)
1135                         *data = cpu_to_be32(card->driver->read_csr(card, reg));
1136                 else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1137                         card->driver->write_csr(card, reg, be32_to_cpu(*data));
1138                 else
1139                         rcode = RCODE_TYPE_ERROR;
1140                 break;
1141
1142         case CSR_RESET_START:
1143                 if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1144                         card->driver->write_csr(card, CSR_STATE_CLEAR,
1145                                                 CSR_STATE_BIT_ABDICATE);
1146                 else
1147                         rcode = RCODE_TYPE_ERROR;
1148                 break;
1149
1150         case CSR_SPLIT_TIMEOUT_HI:
1151                 if (tcode == TCODE_READ_QUADLET_REQUEST) {
1152                         *data = cpu_to_be32(card->split_timeout_hi);
1153                 } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1154                         spin_lock_irqsave(&card->lock, flags);
1155                         card->split_timeout_hi = be32_to_cpu(*data) & 7;
1156                         update_split_timeout(card);
1157                         spin_unlock_irqrestore(&card->lock, flags);
1158                 } else {
1159                         rcode = RCODE_TYPE_ERROR;
1160                 }
1161                 break;
1162
1163         case CSR_SPLIT_TIMEOUT_LO:
1164                 if (tcode == TCODE_READ_QUADLET_REQUEST) {
1165                         *data = cpu_to_be32(card->split_timeout_lo);
1166                 } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
1167                         spin_lock_irqsave(&card->lock, flags);
1168                         card->split_timeout_lo =
1169                                         be32_to_cpu(*data) & 0xfff80000;
1170                         update_split_timeout(card);
1171                         spin_unlock_irqrestore(&card->lock, flags);
1172                 } else {
1173                         rcode = RCODE_TYPE_ERROR;
1174                 }
1175                 break;
1176
1177         case CSR_MAINT_UTILITY:
1178                 if (tcode == TCODE_READ_QUADLET_REQUEST)
1179                         *data = card->maint_utility_register;
1180                 else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1181                         card->maint_utility_register = *data;
1182                 else
1183                         rcode = RCODE_TYPE_ERROR;
1184                 break;
1185
1186         case CSR_BROADCAST_CHANNEL:
1187                 if (tcode == TCODE_READ_QUADLET_REQUEST)
1188                         *data = cpu_to_be32(card->broadcast_channel);
1189                 else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
1190                         card->broadcast_channel =
1191                             (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
1192                             BROADCAST_CHANNEL_INITIAL;
1193                 else
1194                         rcode = RCODE_TYPE_ERROR;
1195                 break;
1196
1197         case CSR_BUS_MANAGER_ID:
1198         case CSR_BANDWIDTH_AVAILABLE:
1199         case CSR_CHANNELS_AVAILABLE_HI:
1200         case CSR_CHANNELS_AVAILABLE_LO:
1201                 /*
1202                  * FIXME: these are handled by the OHCI hardware and
1203                  * the stack never sees these request. If we add
1204                  * support for a new type of controller that doesn't
1205                  * handle this in hardware we need to deal with these
1206                  * transactions.
1207                  */
1208                 BUG();
1209                 break;
1210
1211         default:
1212                 rcode = RCODE_ADDRESS_ERROR;
1213                 break;
1214         }
1215
1216         fw_send_response(card, request, rcode);
1217 }
1218
1219 static struct fw_address_handler registers = {
1220         .length                 = 0x400,
1221         .address_callback       = handle_registers,
1222 };
1223
1224 static void handle_low_memory(struct fw_card *card, struct fw_request *request,
1225                 int tcode, int destination, int source, int generation,
1226                 unsigned long long offset, void *payload, size_t length,
1227                 void *callback_data)
1228 {
1229         /*
1230          * This catches requests not handled by the physical DMA unit,
1231          * i.e., wrong transaction types or unauthorized source nodes.
1232          */
1233         fw_send_response(card, request, RCODE_TYPE_ERROR);
1234 }
1235
1236 static struct fw_address_handler low_memory = {
1237         .length                 = FW_MAX_PHYSICAL_RANGE,
1238         .address_callback       = handle_low_memory,
1239 };
1240
1241 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1242 MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
1243 MODULE_LICENSE("GPL");
1244
1245 static const u32 vendor_textual_descriptor[] = {
1246         /* textual descriptor leaf () */
1247         0x00060000,
1248         0x00000000,
1249         0x00000000,
1250         0x4c696e75,             /* L i n u */
1251         0x78204669,             /* x   F i */
1252         0x72657769,             /* r e w i */
1253         0x72650000,             /* r e     */
1254 };
1255
1256 static const u32 model_textual_descriptor[] = {
1257         /* model descriptor leaf () */
1258         0x00030000,
1259         0x00000000,
1260         0x00000000,
1261         0x4a756a75,             /* J u j u */
1262 };
1263
1264 static struct fw_descriptor vendor_id_descriptor = {
1265         .length = ARRAY_SIZE(vendor_textual_descriptor),
1266         .immediate = 0x03001f11,
1267         .key = 0x81000000,
1268         .data = vendor_textual_descriptor,
1269 };
1270
1271 static struct fw_descriptor model_id_descriptor = {
1272         .length = ARRAY_SIZE(model_textual_descriptor),
1273         .immediate = 0x17023901,
1274         .key = 0x81000000,
1275         .data = model_textual_descriptor,
1276 };
1277
1278 static int __init fw_core_init(void)
1279 {
1280         int ret;
1281
1282         fw_workqueue = alloc_workqueue("firewire", WQ_MEM_RECLAIM, 0);
1283         if (!fw_workqueue)
1284                 return -ENOMEM;
1285
1286         ret = bus_register(&fw_bus_type);
1287         if (ret < 0) {
1288                 destroy_workqueue(fw_workqueue);
1289                 return ret;
1290         }
1291
1292         fw_cdev_major = register_chrdev(0, "firewire", &fw_device_ops);
1293         if (fw_cdev_major < 0) {
1294                 bus_unregister(&fw_bus_type);
1295                 destroy_workqueue(fw_workqueue);
1296                 return fw_cdev_major;
1297         }
1298
1299         fw_core_add_address_handler(&topology_map, &topology_map_region);
1300         fw_core_add_address_handler(&registers, &registers_region);
1301         fw_core_add_address_handler(&low_memory, &low_memory_region);
1302         fw_core_add_descriptor(&vendor_id_descriptor);
1303         fw_core_add_descriptor(&model_id_descriptor);
1304
1305         return 0;
1306 }
1307
1308 static void __exit fw_core_cleanup(void)
1309 {
1310         unregister_chrdev(fw_cdev_major, "firewire");
1311         bus_unregister(&fw_bus_type);
1312         destroy_workqueue(fw_workqueue);
1313         idr_destroy(&fw_device_idr);
1314 }
1315
1316 module_init(fw_core_init);
1317 module_exit(fw_core_cleanup);