1 /* can_queue.c - CAN message queues
2 * Linux CAN-bus device driver.
3 * New CAN queues by Pavel Pisa - OCERA team member
4 * email:pisa@cmp.felk.cvut.cz
5 * This software is released under the GPL-License.
6 * Version lincan-0.2 9 Jul 2003
9 #include "../include/can.h"
10 #include "../include/can_sysdep.h"
11 #include "../include/can_queue.h"
14 * Modifies Tx message processing
15 * 0 .. local message processing disabled
16 * 1 .. local messages disabled by default but can be enabled by canque_set_filt
17 * 2 .. local messages enabled by default, can be disabled by canque_set_filt
19 extern int processlocal;
21 atomic_t edge_num_cnt;
27 #define DEBUGQUE(fmt,args...) can_printk(KERN_ERR "can_queue (debug): " fmt,\
31 #define DEBUGQUE(fmt,args...)
34 #define CANQUE_ROUNDROB 1
38 * canque_fifo_flush_slots - free all ready slots from the FIFO
39 * @fifo: pointer to the FIFO structure
41 * The caller should be prepared to handle situations, when some
42 * slots are held by input or output side slots processing.
43 * These slots cannot be flushed or their processing interrupted.
45 * Return Value: The nonzero value indicates, that queue has not been
46 * empty before the function call.
48 int canque_fifo_flush_slots(struct canque_fifo_t *fifo)
51 can_spin_irqflags_t flags;
52 struct canque_slot_t *slot;
53 can_spin_lock_irqsave(&fifo->fifo_lock, flags);
56 *fifo->tail=fifo->flist;
59 fifo->tail=&fifo->head;
61 canque_fifo_clear_fl(fifo,FULL);
62 ret=canque_fifo_test_and_set_fl(fifo,EMPTY)?0:1;
63 can_spin_unlock_irqrestore(&fifo->fifo_lock, flags);
69 * canque_fifo_init_slots - initializes slot chain of one CAN FIFO
70 * @fifo: pointer to the FIFO structure
72 * Return Value: The negative value indicates, that there is no memory
73 * to allocate space for the requested number of the slots.
75 int canque_fifo_init_slots(struct canque_fifo_t *fifo)
77 struct canque_slot_t *slot;
78 int slotsnr=fifo->slotsnr;
79 if(!fifo->entry || !slotsnr) return -1;
88 fifo->tail=&fifo->head;
89 canque_fifo_set_fl(fifo,EMPTY);
93 /* atomic_dec_and_test(&qedge->edge_used);
94 void atomic_inc(&qedge->edge_used);
95 list_add_tail(struct list_head *new, struct list_head *head)
96 list_for_each(edge,qends->inlist);
97 list_entry(ptr, type, member)
101 * canque_get_inslot - finds one outgoing edge and allocates slot from it
102 * @qends: ends structure belonging to calling communication object
103 * @qedgep: place to store pointer to found edge
104 * @slotp: place to store pointer to allocated slot
105 * @cmd: command type for slot
107 * Function looks for the first non-blocked outgoing edge in @qends structure
108 * and tries to allocate slot from it.
109 * Return Value: If there is no usable edge or there is no free slot in edge
110 * negative value is returned.
112 int canque_get_inslot(struct canque_ends_t *qends,
113 struct canque_edge_t **qedgep, struct canque_slot_t **slotp, int cmd)
116 struct canque_edge_t *edge;
118 edge=canque_first_inedge(qends);
120 if(!canque_fifo_test_fl(&edge->fifo,BLOCK)){
121 ret=canque_fifo_get_inslot(&edge->fifo, slotp, cmd);
124 DEBUGQUE("canque_get_inslot cmd=%d found edge %d\n",cmd,edge->edge_num);
129 canque_edge_decref(edge);
132 DEBUGQUE("canque_get_inslot cmd=%d failed\n",cmd);
137 * canque_get_inslot4id - finds best outgoing edge and slot for given ID
138 * @qends: ends structure belonging to calling communication object
139 * @qedgep: place to store pointer to found edge
140 * @slotp: place to store pointer to allocated slot
141 * @cmd: command type for slot
142 * @id: communication ID of message to send into edge
143 * @prio: optional priority of message
145 * Function looks for the non-blocked outgoing edge accepting messages
146 * with given ID. If edge is found, slot is allocated from that edge.
147 * The edges with non-zero mask are preferred over edges open to all messages.
148 * If more edges with mask accepts given message ID, the edge with
149 * highest priority below or equal to required priority is selected.
150 * Return Value: If there is no usable edge or there is no free slot in edge
151 * negative value is returned.
153 int canque_get_inslot4id(struct canque_ends_t *qends,
154 struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
155 int cmd, unsigned long id, int prio)
158 struct canque_edge_t *edge, *bestedge=NULL;
160 canque_for_each_inedge(qends, edge){
161 if(canque_fifo_test_fl(&edge->fifo,BLOCK))
163 if((id^edge->filtid)&edge->filtmask)
166 if(bestedge->filtmask){
167 if (!edge->filtmask) continue;
170 canque_edge_decref(bestedge);
172 canque_edge_incref(bestedge);
176 if(bestedge->edge_prio<edge->edge_prio){
177 if(edge->edge_prio>prio) continue;
179 if(bestedge->edge_prio<=prio) continue;
181 canque_edge_decref(bestedge);
184 canque_edge_incref(bestedge);
186 if((edge=bestedge)!=NULL){
187 ret=canque_fifo_get_inslot(&edge->fifo, slotp, cmd);
190 DEBUGQUE("canque_get_inslot4id cmd=%d id=%ld prio=%d found edge %d\n",cmd,id,prio,edge->edge_num);
193 canque_edge_decref(bestedge);
196 DEBUGQUE("canque_get_inslot4id cmd=%d id=%ld prio=%d failed\n",cmd,id,prio);
202 * canque_put_inslot - schedules filled slot for processing
203 * @qends: ends structure belonging to calling communication object
204 * @qedge: edge slot belong to
205 * @slot: pointer to the prepared slot
207 * Puts slot previously acquired by canque_get_inslot() or canque_get_inslot4id()
208 * function call into FIFO queue and activates edge processing if needed.
209 * Return Value: Positive value informs, that activation of output end
212 int canque_put_inslot(struct canque_ends_t *qends,
213 struct canque_edge_t *qedge, struct canque_slot_t *slot)
216 ret=canque_fifo_put_inslot(&qedge->fifo,slot);
218 canque_activate_edge(qends,qedge);
219 canque_notify_outends(qedge,CANQUEUE_NOTIFY_PROC);
221 canque_edge_decref(qedge);
222 DEBUGQUE("canque_put_inslot for edge %d returned %d\n",qedge->edge_num,ret);
227 * canque_abort_inslot - aborts preparation of the message in the slot
228 * @qends: ends structure belonging to calling communication object
229 * @qedge: edge slot belong to
230 * @slot: pointer to the previously allocated slot
232 * Frees slot previously acquired by canque_get_inslot() or canque_get_inslot4id()
233 * function call. Used when message copying into slot fails.
234 * Return Value: Positive value informs, that queue full state has been negated.
236 int canque_abort_inslot(struct canque_ends_t *qends,
237 struct canque_edge_t *qedge, struct canque_slot_t *slot)
240 ret=canque_fifo_abort_inslot(&qedge->fifo,slot);
242 canque_notify_outends(qedge,CANQUEUE_NOTIFY_SPACE);
244 canque_edge_decref(qedge);
245 DEBUGQUE("canque_abort_inslot for edge %d returned %d\n",qedge->edge_num,ret);
250 * canque_filter_msg2edges - sends message into all edges which accept its ID
251 * @qends: ends structure belonging to calling communication object
252 * @msg: pointer to CAN message
254 * Sends message to all outgoing edges connected to the given ends, which accepts
255 * message communication ID.
256 * Return Value: Returns number of edges message has been send to
258 int canque_filter_msg2edges(struct canque_ends_t *qends, struct canmsg_t *msg)
263 struct canque_edge_t *edge;
264 struct canque_slot_t *slot;
266 DEBUGQUE("canque_filter_msg2edges for msg ID 0x%08lx and flags 0x%02x\n",
267 msg->id, msg->flags);
268 msgid = canque_filtid2internal(msg->id, msg->flags);
270 canque_for_each_inedge(qends, edge) {
271 if(canque_fifo_test_fl(&edge->fifo,BLOCK))
273 if((msgid^edge->filtid)&edge->filtmask)
275 ret=canque_fifo_get_inslot(&edge->fifo, &slot, 0);
279 ret=canque_fifo_put_inslot(&edge->fifo,slot);
281 canque_activate_edge(qends,edge);
282 canque_notify_outends(edge,CANQUEUE_NOTIFY_PROC);
287 DEBUGQUE("canque_filter_msg2edges sent msg ID %ld to %d edges\n",msg->id,destnr);
292 * canque_test_outslot - test and retrieve ready slot for given ends
293 * @qends: ends structure belonging to calling communication object
294 * @qedgep: place to store pointer to found edge
295 * @slotp: place to store pointer to received slot
297 * Function takes highest priority active incoming edge and retrieves
298 * oldest ready slot from it.
299 * Return Value: Negative value informs, that there is no ready output
300 * slot for given ends. Positive value is equal to the command
301 * slot has been allocated by the input side.
303 int canque_test_outslot(struct canque_ends_t *qends,
304 struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
306 can_spin_irqflags_t flags;
308 struct canque_edge_t *edge;
311 can_spin_lock_irqsave(&qends->ends_lock, flags);
312 for(prio=CANQUEUE_PRIO_NR;--prio>=0;){
313 while(!list_empty(&qends->active[prio])){
314 edge=list_entry(qends->active[prio].next,struct canque_edge_t,activepeers);
315 if(!canque_fifo_test_fl(&edge->fifo,DEAD)) {
316 /* The first test on unlocked FIFO */
317 if(canque_fifo_test_fl(&edge->fifo,EMPTY)) {
318 can_spin_lock(&edge->fifo.fifo_lock);
319 /* Test has to be repeated to ensure that EMPTY
320 state has not been nagated when locking FIFO */
321 if(canque_fifo_test_fl(&edge->fifo,EMPTY)) {
322 canque_fifo_set_fl(&edge->fifo,INACTIVE);
323 list_del(&edge->activepeers);
324 list_add(&edge->activepeers,&qends->idle);
325 can_spin_unlock(&edge->fifo.fifo_lock);
328 can_spin_unlock(&edge->fifo.fifo_lock);
330 canque_edge_incref(edge);
331 can_spin_unlock_irqrestore(&qends->ends_lock, flags);
333 DEBUGQUE("canque_test_outslot found edge %d\n",edge->edge_num);
334 ret=canque_fifo_test_outslot(&edge->fifo, slotp);
338 canque_edge_decref(edge);
339 can_spin_lock_irqsave(&qends->ends_lock, flags);
341 can_spin_lock(&edge->fifo.fifo_lock);
342 canque_fifo_set_fl(&edge->fifo,INACTIVE);
343 list_del(&edge->activepeers);
344 list_add(&edge->activepeers,&qends->idle);
345 can_spin_unlock(&edge->fifo.fifo_lock);
349 can_spin_unlock_irqrestore(&qends->ends_lock, flags);
351 DEBUGQUE("canque_test_outslot no ready slot\n");
356 * canque_free_outslot - frees processed output slot
357 * @qends: ends structure belonging to calling communication object
358 * @qedge: edge slot belong to
359 * @slot: pointer to the processed slot
361 * Function releases processed slot previously acquired by canque_test_outslot()
363 * Return Value: Return value informs if input side has been notified
364 * to know about change of edge state
366 int canque_free_outslot(struct canque_ends_t *qends,
367 struct canque_edge_t *qedge, struct canque_slot_t *slot)
370 can_spin_irqflags_t flags;
371 ret=canque_fifo_free_outslot(&qedge->fifo, slot);
372 if(ret&CAN_FIFOF_EMPTY){
373 canque_notify_inends(qedge,CANQUEUE_NOTIFY_EMPTY);
375 if(ret&CAN_FIFOF_FULL)
376 canque_notify_inends(qedge,CANQUEUE_NOTIFY_SPACE);
377 can_spin_lock_irqsave(&qends->ends_lock, flags);
378 if((ret&CAN_FIFOF_EMPTY) || CANQUE_ROUNDROB ){
379 can_spin_lock(&qedge->fifo.fifo_lock);
380 if(canque_fifo_test_fl(&qedge->fifo,EMPTY)){
381 canque_fifo_set_fl(&qedge->fifo,INACTIVE);
382 list_del(&qedge->activepeers);
383 list_add(&qedge->activepeers,&qends->idle);
385 list_del(&qedge->activepeers);
386 list_add_tail(&qedge->activepeers,&qends->active[qedge->edge_prio]);
388 can_spin_unlock(&qedge->fifo.fifo_lock);
390 can_spin_unlock_irqrestore(&qends->ends_lock, flags);
391 canque_edge_decref(qedge);
392 DEBUGQUE("canque_free_outslot for edge %d returned %d\n",qedge->edge_num,ret);
397 * canque_again_outslot - reschedule output slot to process it again later
398 * @qends: ends structure belonging to calling communication object
399 * @qedge: edge slot belong to
400 * @slot: pointer to the slot for re-processing
402 * Function reschedules slot previously acquired by canque_test_outslot()
403 * function call for second time processing.
404 * Return Value: Function cannot fail.
406 int canque_again_outslot(struct canque_ends_t *qends,
407 struct canque_edge_t *qedge, struct canque_slot_t *slot)
410 ret=canque_fifo_again_outslot(&qedge->fifo, slot);
411 canque_edge_decref(qedge);
412 DEBUGQUE("canque_again_outslot for edge %d returned %d\n",qedge->edge_num,ret);
417 * canque_set_filt - sets filter for specified edge
418 * @qedge: pointer to the edge
419 * @filtid: ID to set for the edge
420 * @filtmask: mask used for ID match check
421 * @filtflags: required filer flags
423 * Return Value: Negative value is returned if edge is in the process of delete.
425 int canque_set_filt(struct canque_edge_t *qedge,
426 unsigned long filtid, unsigned long filtmask, int filtflags)
429 can_spin_irqflags_t flags;
431 can_spin_lock_irqsave(&qedge->fifo.fifo_lock,flags);
433 if(!(filtflags&MSG_PROCESSLOCAL) && (processlocal<2))
434 filtflags |= MSG_LOCAL_MASK;
436 qedge->filtid=canque_filtid2internal(filtid, filtflags);
437 qedge->filtmask=canque_filtid2internal(filtmask, filtflags>>MSG_FILT_MASK_SHIFT);
439 if(canque_fifo_test_fl(&qedge->fifo,DEAD)) ret=-1;
440 else ret=canque_fifo_test_and_set_fl(&qedge->fifo,BLOCK)?1:0;
442 can_spin_unlock_irqrestore(&qedge->fifo.fifo_lock,flags);
444 canque_notify_bothends(qedge,CANQUEUE_NOTIFY_FILTCH);
446 can_spin_lock_irqsave(&qedge->fifo.fifo_lock,flags);
447 if(!ret) canque_fifo_clear_fl(&qedge->fifo,BLOCK);
448 can_spin_unlock_irqrestore(&qedge->fifo.fifo_lock,flags);
450 DEBUGQUE("canque_set_filt for edge %d, ID %ld, mask %ld, flags %d returned %d\n",
451 qedge->edge_num,filtid,filtmask,filtflags,ret);
456 * canque_flush - fluesh all ready slots in the edge
457 * @qedge: pointer to the edge
459 * Tries to flush all allocated slots from the edge, but there could
460 * exist some slots associated to edge which are processed by input
461 * or output side and cannot be flushed at this moment.
462 * Return Value: The nonzero value indicates, that queue has not been
463 * empty before the function call.
465 int canque_flush(struct canque_edge_t *qedge)
468 can_spin_irqflags_t flags;
470 ret=canque_fifo_flush_slots(&qedge->fifo);
472 canque_notify_inends(qedge,CANQUEUE_NOTIFY_EMPTY);
473 canque_notify_inends(qedge,CANQUEUE_NOTIFY_SPACE);
474 can_spin_lock_irqsave(&qedge->outends->ends_lock, flags);
475 can_spin_lock(&qedge->fifo.fifo_lock);
476 if(canque_fifo_test_fl(&qedge->fifo,EMPTY)){
477 list_del(&qedge->activepeers);
478 list_add(&qedge->activepeers,&qedge->outends->idle);
480 can_spin_unlock(&qedge->fifo.fifo_lock);
481 can_spin_unlock_irqrestore(&qedge->outends->ends_lock, flags);
483 DEBUGQUE("canque_flush for edge %d returned %d\n",qedge->edge_num,ret);
488 * canqueue_ends_init_gen - subsystem independent routine to initialize ends state
489 * @qends: pointer to the ends structure
491 * Return Value: Cannot fail.
493 int canqueue_ends_init_gen(struct canque_ends_t *qends)
497 for(i=CANQUEUE_PRIO_NR;--i>=0;){
498 INIT_LIST_HEAD(&qends->active[i]);
500 INIT_LIST_HEAD(&qends->idle);
501 INIT_LIST_HEAD(&qends->inlist);
502 INIT_LIST_HEAD(&qends->outlist);
503 can_spin_lock_init(&qends->ends_lock);
509 * canqueue_connect_edge - connect edge between two communication entities
510 * @qedge: pointer to edge
511 * @inends: pointer to ends the input of the edge should be connected to
512 * @outends: pointer to ends the output of the edge should be connected to
514 * Return Value: Negative value informs about failed operation.
516 int canqueue_connect_edge(struct canque_edge_t *qedge, struct canque_ends_t *inends, struct canque_ends_t *outends)
518 can_spin_irqflags_t flags;
519 if(qedge == NULL) return -1;
520 DEBUGQUE("canqueue_connect_edge %d\n",qedge->edge_num);
521 canque_edge_incref(qedge);
522 can_spin_lock_irqsave(&inends->ends_lock, flags);
523 can_spin_lock(&outends->ends_lock);
524 can_spin_lock(&qedge->fifo.fifo_lock);
525 qedge->inends=inends;
526 list_add(&qedge->inpeers,&inends->inlist);
527 qedge->outends=outends;
528 list_add(&qedge->outpeers,&outends->outlist);
529 list_add(&qedge->activepeers,&outends->idle);
530 can_spin_unlock(&qedge->fifo.fifo_lock);
531 can_spin_unlock(&outends->ends_lock);
532 can_spin_unlock_irqrestore(&inends->ends_lock, flags);
533 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_ATTACH);
535 if(canque_fifo_test_and_set_fl(&qedge->fifo, READY))
536 canque_edge_decref(qedge);
541 * canqueue_disconnect_edge - disconnect edge from communicating entities
542 * @qedge: pointer to edge
544 * Return Value: Negative value means, that edge is used by somebody
545 * other and cannot be disconnected. Operation has to be delayed.
547 int canqueue_disconnect_edge(struct canque_edge_t *qedge)
550 can_spin_irqflags_t flags;
551 struct canque_ends_t *inends, *outends;
553 inends=qedge->inends;
554 if(inends) can_spin_lock_irqsave(&inends->ends_lock,flags);
555 outends=qedge->outends;
556 if(outends) can_spin_lock(&outends->ends_lock);
557 can_spin_lock(&qedge->fifo.fifo_lock);
558 if(atomic_read(&qedge->edge_used)==0) {
560 list_del(&qedge->activepeers);
561 mb(); /* memory barrier for list_empty use in canque_dead_func */
562 list_del(&qedge->outpeers);
566 list_del(&qedge->inpeers);
571 can_spin_unlock(&qedge->fifo.fifo_lock);
572 if(outends) can_spin_unlock(&outends->ends_lock);
573 if(inends) can_spin_unlock_irqrestore(&inends->ends_lock,flags);
574 DEBUGQUE("canqueue_disconnect_edge %d returned %d\n",qedge->edge_num,ret);
580 * canqueue_block_inlist - block slot allocation of all outgoing edges of specified ends
581 * @qends: pointer to ends structure
583 void canqueue_block_inlist(struct canque_ends_t *qends)
585 struct canque_edge_t *edge;
587 canque_for_each_inedge(qends, edge) {
588 canque_fifo_set_fl(&edge->fifo,BLOCK);
594 * canqueue_block_outlist - block slot allocation of all incoming edges of specified ends
595 * @qends: pointer to ends structure
597 void canqueue_block_outlist(struct canque_ends_t *qends)
599 struct canque_edge_t *edge;
601 canque_for_each_outedge(qends, edge) {
602 canque_fifo_set_fl(&edge->fifo,BLOCK);
608 * canqueue_ends_kill_inlist - sends request to die to all outgoing edges
609 * @qends: pointer to ends structure
610 * @send_rest: select, whether already allocated slots should be processed
611 * by FIFO output side
613 * Return Value: Non-zero value means, that not all edges could be immediately
614 * disconnected and that ends structure memory release has to be delayed
616 int canqueue_ends_kill_inlist(struct canque_ends_t *qends, int send_rest)
618 struct canque_edge_t *edge;
620 canque_for_each_inedge(qends, edge){
621 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
623 canque_edge_incref(edge);
624 if(!canque_fifo_test_and_set_fl(&edge->fifo, FREEONEMPTY)){
625 if(!canque_fifo_test_fl(&edge->fifo, EMPTY))
627 if(!canque_fifo_test_and_clear_fl(&edge->fifo, FREEONEMPTY))
630 canque_edge_decref(edge);
633 return list_empty(&qends->inlist)?0:1;
638 * canqueue_ends_kill_outlist - sends request to die to all incoming edges
639 * @qends: pointer to ends structure
641 * Return Value: Non-zero value means, that not all edges could be immediately
642 * disconnected and that ends structure memory release has to be delayed
644 int canqueue_ends_kill_outlist(struct canque_ends_t *qends)
646 struct canque_edge_t *edge;
648 canque_for_each_outedge(qends, edge){
649 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
651 return list_empty(&qends->outlist)?0:1;
656 * canqueue_ends_filt_conjuction - computes conjunction of incoming edges filters filters
657 * @qends: pointer to ends structure
658 * @filt: pointer the filter structure filled by computed filters conjunction
660 * Return Value: Number of incoming edges
662 int canqueue_ends_filt_conjuction(struct canque_ends_t *qends, struct canfilt_t *filt)
664 struct canque_edge_t *edge;
666 unsigned long filtid=0;
667 unsigned long filtmask=~0;
668 unsigned long local_only=canque_filtid2internal(0,MSG_LOCAL);
670 canque_for_each_inedge(qends, edge){
671 /* skip edges processing only local messages */
672 if(edge->filtid & edge->filtmask & local_only)
676 filtid = edge->filtid;
678 filtmask &= ~(filtid ^ edge->filtid);
680 filtmask &= edge->filtmask;
683 filt->id = filtid & MSG_ID_MASK;
684 filt->mask = filtmask & MSG_ID_MASK;
687 filt->flags = filtid & MSG_EXT;
688 if(filtmask & (MSG_EXT))
689 filt->flags |= MSG_EXT_MASK;
690 if(filtid & (MSG_RTR<<1))
691 filt->flags |= MSG_RTR<<1;
692 if(filtmask & (MSG_RTR<<1))
693 filt->flags |= MSG_RTR_MASK;