1 /* can_quekern.c - CAN message queues functions for the Linux kernel
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-0.3 17 Jun 2004
10 #include "./can/can_sysdep.h"
11 #include "./can/can_queue.h"
15 extern atomic_t edge_num_cnt;
18 #define DEBUGQUE(fmt,args...) can_printk(KERN_ERR "can_quesysless (debug): " fmt,\
22 #define DEBUGQUE(fmt,args...)
25 #define ERRMSGQUE(fmt,args...) can_printk(KERN_ERR "can_quesysless: " fmt,\
30 * Modifies Tx message processing
31 * 0 .. local message processing disabled
32 * 1 .. local messages disabled by default but can be enabled by canque_set_filt
33 * 2 .. local messages enabled by default, can be disabled by canque_set_filt
35 extern int processlocal;
37 void canque_dead_func(unsigned long data);
39 /* Support for dead ends structures left after client close */
40 can_spinlock_t canque_dead_func_lock;
41 LIST_HEAD(canque_dead_ends);
42 /* retrieved by list_entry(canque_dead_ends.next,struct canque_ends_t,dead_peers) */
43 LIST_HEAD(canque_dead_edges);
44 /* retrieved by list_entry(canque_dead_edges.next,struct canque_edge_t,inpeers) */
45 // DECLARE_TASKLET(canque_dead_tl, canque_dead_func, 0);
46 /* activated by tasklet_schedule(&canque_dead_tl) */
50 struct canque_edge_t *canque_dead_edges_cut_first(void)
52 can_spin_irqflags_t flags;
53 struct canque_edge_t *edge;
54 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
55 if(list_empty(&canque_dead_edges))
58 edge=list_entry(canque_dead_edges.next,struct canque_edge_t,inpeers);
59 list_del(&edge->inpeers);
61 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
65 void canque_dead_func(unsigned long data)
67 can_spin_irqflags_t flags;
68 struct canque_edge_t *qedge;
69 struct canque_ends_t *qends;
70 struct list_head *entry;
72 while((qedge=canque_dead_edges_cut_first())){
73 DEBUGQUE("edge %d disposed\n",qedge->edge_num);
75 if(canque_fifo_test_fl(&qedge->fifo,RTL_MEM)){
76 canque_dispose_edge_rtl(qedge);
79 #endif /*CAN_WITH_RTL*/
80 canque_fifo_done_kern(&qedge->fifo);
84 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
85 entry=canque_dead_ends.next;
86 while(entry!=&canque_dead_ends){
87 qends=list_entry(entry,struct canque_ends_t,dead_peers);
89 if(!list_empty(&qends->inlist))
91 if(!list_empty(&qends->outlist))
93 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
94 list_del(&qends->dead_peers);
95 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
96 DEBUGQUE("ends structure disposed\n");
98 if(qends->ends_flags&CAN_ENDSF_MEM_RTL){
99 canque_ends_free_rtl(qends);
102 #endif /*CAN_WITH_RTL*/
105 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
108 // static inline void canque_dead_tasklet_schedule(void)
110 // #ifdef CAN_WITH_RTL
111 // if(!rtl_rt_system_is_idle()){
112 // set_bit(CAN_RTL2LIN_PEND_DEAD_b,&canqueue_rtl2lin_pend);
113 // rtl_global_pend_irq (canqueue_rtl_irq);
116 // #endif /*CAN_WITH_RTL*/
118 // tasklet_schedule(&canque_dead_tl);
122 void canque_edge_do_dead(struct canque_edge_t *edge)
124 can_spin_irqflags_t flags;
126 canque_notify_bothends(edge,CANQUEUE_NOTIFY_NOUSR);
128 /* The problem of the above call is, that in RT-Linux to Linux notify
129 case is edge scheduled for delayed notify delivery, this needs
130 to be reflected there */
131 if(atomic_read(&edge->edge_used)>0){
132 can_spin_lock_irqsave(&edge->inends->ends_lock, flags);
133 can_spin_lock(&edge->outends->ends_lock);
134 if(atomic_read(&edge->edge_used)>0){
135 /* left edge to live for a while, banshee comes again in a while */
136 canque_fifo_clear_fl(&edge->fifo,DEAD);
137 can_spin_unlock(&edge->outends->ends_lock);
138 can_spin_unlock_irqrestore(&edge->inends->ends_lock, flags);
139 can_printk(KERN_ERR "can_quertl (debug): canque_edge_do_dead postponed\n");
142 can_spin_unlock(&edge->outends->ends_lock);
143 can_spin_unlock_irqrestore(&edge->inends->ends_lock, flags);
145 #endif /*CAN_WITH_RTL*/
147 if(canqueue_disconnect_edge(edge)<0){
148 ERRMSGQUE("canque_edge_do_dead: canqueue_disconnect_edge failed !!!\n");
152 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
153 list_add(&edge->inpeers,&canque_dead_edges);
154 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
155 // canque_dead_tasklet_schedule();
161 /*if(qends->ends_flags & CAN_ENDSF_DEAD){
162 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
163 list_del(&qends->dead_peers);
164 list_add(&qends->dead_peers,&canque_dead_ends);
165 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
166 tasklet_schedule(&canque_dead_tl);
171 * canqueue_notify_kern - notification callback handler for Linux userspace clients
172 * @qends: pointer to the callback side ends structure
173 * @qedge: edge which invoked notification
174 * @what: notification type
176 * The notification event is handled directly by call of this function except case,
177 * when called from RT-Linux context in mixed mode Linux/RT-Linux compilation.
178 * It is not possible to directly call Linux kernel synchronization primitives
179 * in such case. The notification request is postponed and signaled by @pending_inops flags
180 * by call canqueue_rtl2lin_check_and_pend() function.
181 * The edge reference count is increased until until all pending notifications are processed.
183 void canqueue_notify_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge, int what)
185 DEBUGQUE("canqueue_notify_kern for edge %d, use %d and event %d\n",
186 qedge->edge_num,(int)atomic_read(&qedge->edge_used),what);
188 /* delay event delivery for RT-Linux -> kernel notifications */
189 if(canqueue_rtl2lin_check_and_pend(qends,qedge,what)){
190 DEBUGQUE("canqueue_notify_kern postponed\n");
195 case CANQUEUE_NOTIFY_EMPTY:
196 // wake_up(&qends->endinfo.fileinfo.emptyq);
197 if(canque_fifo_test_and_clear_fl(&qedge->fifo, FREEONEMPTY))
198 canque_edge_decref(qedge);
200 case CANQUEUE_NOTIFY_SPACE:
201 // wake_up(&qends->endinfo.fileinfo.writeq);
202 #ifdef CAN_ENABLE_KERN_FASYNC
203 /* Asynchronous I/O processing */
204 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_OUT);
205 #endif /*CAN_ENABLE_KERN_FASYNC*/
207 case CANQUEUE_NOTIFY_PROC:
208 // wake_up(&qends->endinfo.fileinfo.readq);
209 #ifdef CAN_ENABLE_KERN_FASYNC
210 /* Asynchronous I/O processing */
211 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_IN);
212 #endif /*CAN_ENABLE_KERN_FASYNC*/
214 case CANQUEUE_NOTIFY_NOUSR:
215 // wake_up(&qends->endinfo.fileinfo.readq);
216 // wake_up(&qends->endinfo.fileinfo.writeq);
217 // wake_up(&qends->endinfo.fileinfo.emptyq);
219 case CANQUEUE_NOTIFY_DEAD_WANTED:
220 case CANQUEUE_NOTIFY_DEAD:
221 if(canque_fifo_test_and_clear_fl(&qedge->fifo, READY))
222 canque_edge_decref(qedge);
224 case CANQUEUE_NOTIFY_ATTACH:
230 * canqueue_ends_init_kern - Linux userspace clients specific ends initialization
231 * @qends: pointer to the callback side ends structure
233 int canqueue_ends_init_kern(struct canque_ends_t *qends)
235 canqueue_ends_init_gen(qends);
237 init_waitqueue_head(&qends->endinfo.fileinfo.readq);
238 init_waitqueue_head(&qends->endinfo.fileinfo.writeq);
239 init_waitqueue_head(&qends->endinfo.fileinfo.emptyq);
240 #ifdef CAN_ENABLE_KERN_FASYNC
241 qends->endinfo.fileinfo.fasync=NULL;
242 #endif /*CAN_ENABLE_KERN_FASYNC*/
244 qends->notify=canqueue_notify_kern;
245 DEBUGQUE("canqueue_ends_init_kern\n");
251 * canque_get_inslot4id_wait_kern - find or wait for best outgoing edge and slot for given ID
252 * @qends: ends structure belonging to calling communication object
253 * @qedgep: place to store pointer to found edge
254 * @slotp: place to store pointer to allocated slot
255 * @cmd: command type for slot
256 * @id: communication ID of message to send into edge
257 * @prio: optional priority of message
259 * Same as canque_get_inslot4id(), except, that it waits for free slot
260 * in case, that queue is full. Function is specific for Linux userspace clients.
261 * Return Value: If there is no usable edge negative value is returned.
263 // int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
264 // struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
265 // int cmd, unsigned long id, int prio)
268 // DEBUGQUE("canque_get_inslot4id_wait_kern for cmd %d, id %ld, prio %d\n",cmd,id,prio);
269 // wait_event_interruptible((qends->endinfo.fileinfo.writeq),
270 // (ret=canque_get_inslot4id(qends,qedgep,slotp,cmd,id,prio))!=-1);
275 * canque_get_outslot_wait_kern - receive or wait for ready slot for given ends
276 * @qends: ends structure belonging to calling communication object
277 * @qedgep: place to store pointer to found edge
278 * @slotp: place to store pointer to received slot
280 * The same as canque_test_outslot(), except it waits in the case, that there is
281 * no ready slot for given ends. Function is specific for Linux userspace clients.
282 * Return Value: Negative value informs, that there is no ready output
283 * slot for given ends. Positive value is equal to the command
284 * slot has been allocated by the input side.
286 // int canque_get_outslot_wait_kern(struct canque_ends_t *qends,
287 // struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
290 // DEBUGQUE("canque_get_outslot_wait_kern\n");
291 // wait_event_interruptible((qends->endinfo.fileinfo.readq),
292 // (ret=canque_test_outslot(qends,qedgep,slotp))!=-1);
297 * canque_sync_wait_kern - wait for all slots processing
298 * @qends: ends structure belonging to calling communication object
299 * @qedge: pointer to edge
301 * Functions waits for ends transition into empty state.
302 * Return Value: Positive value indicates, that edge empty state has been reached.
303 * Negative or zero value informs about interrupted wait or other problem.
305 // int canque_sync_wait_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
308 // DEBUGQUE("canque_sync_wait_kern\n");
309 // wait_event_interruptible((qends->endinfo.fileinfo.emptyq),
310 // (ret=canque_fifo_test_fl(&qedge->fifo,EMPTY)?1:0));
316 * canque_fifo_init_kern - initialize one CAN FIFO
317 * @fifo: pointer to the FIFO structure
318 * @slotsnr: number of requested slots
320 * Return Value: The negative value indicates, that there is no memory
321 * to allocate space for the requested number of the slots.
323 int canque_fifo_init_kern(struct canque_fifo_t *fifo, int slotsnr)
326 if(!slotsnr) slotsnr=MAX_BUF_LENGTH;
327 size=sizeof(struct canque_slot_t)*slotsnr;
328 fifo->entry=malloc(size);
329 if(!fifo->entry) return -1;
330 fifo->slotsnr=slotsnr;
331 return canque_fifo_init_slots(fifo);
335 * canque_fifo_done_kern - frees slots allocated for CAN FIFO
336 * @fifo: pointer to the FIFO structure
338 int canque_fifo_done_kern(struct canque_fifo_t *fifo)
348 * canque_new_edge_kern - allocate new edge structure in the Linux kernel context
349 * @slotsnr: required number of slots in the newly allocated edge structure
351 * Return Value: Returns pointer to allocated slot structure or %NULL if
352 * there is not enough memory to process operation.
354 struct canque_edge_t *canque_new_edge_kern(int slotsnr)
356 struct canque_edge_t *qedge;
357 qedge = (struct canque_edge_t *)malloc(sizeof(struct canque_edge_t));
358 if(qedge == NULL) return NULL;
360 memset(qedge,0,sizeof(struct canque_edge_t));
361 can_spin_lock_init(&qedge->fifo.fifo_lock);
362 if(canque_fifo_init_kern(&qedge->fifo, slotsnr)<0){
364 DEBUGQUE("canque_new_edge_kern failed\n");
367 atomic_set(&qedge->edge_used,1);
369 qedge->filtmask = canque_filtid2internal(0l, (processlocal<2)? MSG_LOCAL:0);
370 qedge->edge_prio = 0;
372 /* not exactly clean, but enough for debugging */
373 atomic_inc(&edge_num_cnt);
374 qedge->edge_num=atomic_read(&edge_num_cnt);
375 #endif /* CAN_DEBUG */
376 DEBUGQUE("canque_new_edge_kern %d\n",qedge->edge_num);
380 #ifdef USE_SYNC_DISCONNECT_EDGE_KERN
382 /*not included in doc
383 * canqueue_disconnect_edge_kern - disconnect edge from communicating entities with wait
384 * @qends: ends structure belonging to calling communication object
385 * @qedge: pointer to edge
387 * Same as canqueue_disconnect_edge(), but tries to wait for state with zero
389 * Return Value: Negative value means, that edge is used and cannot
390 * be disconnected yet. Operation has to be delayed.
392 int canqueue_disconnect_edge_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
394 canque_fifo_set_fl(&qedge->fifo,BLOCK);
395 DEBUGQUE("canqueue_disconnect_edge_kern %d called\n",qedge->edge_num);
396 if(!canque_fifo_test_and_set_fl(&qedge->fifo,DEAD)){
397 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_DEAD);
399 if(atomic_read(&qedge->edge_used)>0)
400 atomic_dec(&qedge->edge_used);
402 DEBUGQUE("canqueue_disconnect_edge_kern %d waiting\n",qedge->edge_num);
403 wait_event((qends->endinfo.fileinfo.emptyq),
404 (canqueue_disconnect_edge(qedge)>=0));
406 /*set_current_state(TASK_UNINTERRUPTIBLE);*/
407 /*schedule_timeout(HZ);*/
410 DEBUGQUE("canqueue_disconnect_edge_kern cannot set DEAD\n");
416 int canqueue_disconnect_list_kern(struct canque_ends_t *qends, struct list_head *list)
418 struct canque_edge_t *edge;
419 can_spin_irqflags_t flags;
421 can_spin_lock_irqsave(&qends->ends_lock,flags);
422 if(list_empty(list)){
423 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
426 if(list == &qends->inlist)
427 edge=list_entry(list->next,struct canque_edge_t,inpeers);
429 edge=list_entry(list->next,struct canque_edge_t,outpeers);
430 atomic_inc(&edge->edge_used);
431 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
432 if(canqueue_disconnect_edge_kern(qends, edge)>=0) {
433 /* Free edge memory */
434 canque_fifo_done_kern(&edge->fifo);
437 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
438 canque_edge_decref(edge);
439 DEBUGQUE("canqueue_disconnect_list_kern in troubles\n");
440 DEBUGQUE("the edge %d has usage count %d and flags %ld\n",edge->edge_num,atomic_read(&edge->edge_used),edge->fifo.fifo_flags);
446 #endif /*USE_SYNC_DISCONNECT_EDGE_KERN*/
449 // int canqueue_ends_sync_all_kern(struct canque_ends_t *qends)
451 // struct canque_edge_t *qedge;
453 // canque_for_each_inedge(qends, qedge){
454 // DEBUGQUE("canque_sync_wait_kern called for edge %d\n",qedge->edge_num);
455 // canque_sync_wait_kern(qends, qedge);
461 void canqueue_ends_dispose_postpone(struct canque_ends_t *qends)
463 can_spin_irqflags_t flags;
465 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
466 qends->ends_flags |= CAN_ENDSF_DEAD;
467 list_add(&qends->dead_peers,&canque_dead_ends);
468 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
470 // canque_dead_tasklet_schedule();
475 * canqueue_ends_dispose_kern - finalizing of the ends structure for Linux kernel clients
476 * @qends: pointer to ends structure
477 * @sync: flag indicating, that user wants to wait for processing of all remaining
480 * Return Value: Function should be designed such way to not fail.
482 // int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync)
486 // DEBUGQUE("canqueue_ends_dispose_kern\n");
487 // canqueue_block_inlist(qends);
488 // canqueue_block_outlist(qends);
490 // /*Wait for sending of all pending messages in the output FIFOs*/
492 // canqueue_ends_sync_all_kern(qends);
494 // /* Finish or kill all outgoing edges listed in inends */
495 // delayed=canqueue_ends_kill_inlist(qends, 1);
496 // /* Kill all incoming edges listed in outends */
497 // delayed|=canqueue_ends_kill_outlist(qends);
499 // // wake_up(&qends->endinfo.fileinfo.readq);
500 // // wake_up(&qends->endinfo.fileinfo.writeq);
501 // // wake_up(&qends->endinfo.fileinfo.emptyq);
504 // canqueue_ends_dispose_postpone(qends);
506 // DEBUGQUE("canqueue_ends_dispose_kern delayed\n");
511 // DEBUGQUE("canqueue_ends_dispose_kern finished\n");
515 void canqueue_kern_initialize()
517 can_spin_lock_init(&canque_dead_func_lock);