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_quekern (debug): " fmt,\
22 #define DEBUGQUE(fmt,args...)
25 #define ERRMSGQUE(fmt,args...) can_printk(KERN_ERR "can_quekern: " 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 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
87 /* lock can be released there, because only one instance of canque_dead_tl
88 can run at once and all other functions add ends only to head */
89 while(entry!=&canque_dead_ends){
90 qends=list_entry(entry,struct canque_ends_t,dead_peers);
92 if(!list_empty(&qends->inlist))
94 if(!list_empty(&qends->outlist))
96 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
97 list_del(&qends->dead_peers);
98 can_spin_unlock_irqrestore(&canque_dead_func_lock,flags);
99 DEBUGQUE("ends structure disposed\n");
101 if(qends->ends_flags&CAN_ENDSF_MEM_RTL){
102 canque_ends_free_rtl(qends);
105 #endif /*CAN_WITH_RTL*/
111 static inline void canque_dead_tasklet_schedule(void)
114 if(!rtl_rt_system_is_idle()){
115 set_bit(CAN_RTL2LIN_PEND_DEAD_b,&canqueue_rtl2lin_pend);
116 rtl_global_pend_irq (canqueue_rtl_irq);
119 #endif /*CAN_WITH_RTL*/
121 tasklet_schedule(&canque_dead_tl);
125 void canque_edge_do_dead(struct canque_edge_t *edge)
127 can_spin_irqflags_t flags;
129 canque_notify_bothends(edge,CANQUEUE_NOTIFY_NOUSR);
131 /* The problem of the above call is, that in RT-Linux to Linux notify
132 case is edge scheduled for delayed notify delivery, this needs
133 to be reflected there */
134 if(atomic_read(&edge->edge_used)>0){
135 can_spin_lock_irqsave(&edge->inends->ends_lock, flags);
136 can_spin_lock(&edge->outends->ends_lock);
137 if(atomic_read(&edge->edge_used)>0){
138 /* left edge to live for a while, banshee comes again in a while */
139 canque_fifo_clear_fl(&edge->fifo,DEAD);
140 can_spin_unlock(&edge->outends->ends_lock);
141 can_spin_unlock_irqrestore(&edge->inends->ends_lock, flags);
142 can_printk(KERN_ERR "can_quertl (debug): canque_edge_do_dead postponed\n");
145 can_spin_unlock(&edge->outends->ends_lock);
146 can_spin_unlock_irqrestore(&edge->inends->ends_lock, flags);
148 #endif /*CAN_WITH_RTL*/
150 if(canqueue_disconnect_edge(edge)<0){
151 ERRMSGQUE("canque_edge_do_dead: canqueue_disconnect_edge failed !!!\n");
155 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
156 list_add(&edge->inpeers,&canque_dead_edges);
157 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
158 canque_dead_tasklet_schedule();
163 /*if(qends->ends_flags & CAN_ENDSF_DEAD){
164 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
165 list_del(&qends->dead_peers);
166 list_add(&qends->dead_peers,&canque_dead_ends);
167 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
168 tasklet_schedule(&canque_dead_tl);
173 * canqueue_notify_kern - notification callback handler for Linux userspace clients
174 * @qends: pointer to the callback side ends structure
175 * @qedge: edge which invoked notification
176 * @what: notification type
178 * The notification event is handled directly by call of this function except case,
179 * when called from RT-Linux context in mixed mode Linux/RT-Linux compilation.
180 * It is not possible to directly call Linux kernel synchronization primitives
181 * in such case. The notification request is postponed and signaled by @pending_inops flags
182 * by call canqueue_rtl2lin_check_and_pend() function.
183 * The edge reference count is increased until until all pending notifications are processed.
185 void canqueue_notify_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge, int what)
187 DEBUGQUE("canqueue_notify_kern for edge %d, use %d and event %d\n",
188 qedge->edge_num,(int)atomic_read(&qedge->edge_used),what);
190 /* delay event delivery for RT-Linux -> kernel notifications */
191 if(canqueue_rtl2lin_check_and_pend(qends,qedge,what)){
192 DEBUGQUE("canqueue_notify_kern postponed\n");
197 case CANQUEUE_NOTIFY_EMPTY:
198 wake_up(&qends->endinfo.fileinfo.emptyq);
199 if(canque_fifo_test_and_clear_fl(&qedge->fifo, FREEONEMPTY))
200 canque_edge_decref(qedge);
202 case CANQUEUE_NOTIFY_SPACE:
203 wake_up(&qends->endinfo.fileinfo.writeq);
204 #ifdef CAN_ENABLE_KERN_FASYNC
205 /* Asynchronous I/O processing */
206 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_OUT);
207 #endif /*CAN_ENABLE_KERN_FASYNC*/
209 case CANQUEUE_NOTIFY_PROC:
210 wake_up(&qends->endinfo.fileinfo.readq);
211 #ifdef CAN_ENABLE_KERN_FASYNC
212 /* Asynchronous I/O processing */
213 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_IN);
214 #endif /*CAN_ENABLE_KERN_FASYNC*/
216 case CANQUEUE_NOTIFY_NOUSR:
217 wake_up(&qends->endinfo.fileinfo.readq);
218 wake_up(&qends->endinfo.fileinfo.writeq);
219 wake_up(&qends->endinfo.fileinfo.emptyq);
221 case CANQUEUE_NOTIFY_DEAD_WANTED:
222 case CANQUEUE_NOTIFY_DEAD:
223 if(canque_fifo_test_and_clear_fl(&qedge->fifo, READY))
224 canque_edge_decref(qedge);
226 case CANQUEUE_NOTIFY_ATTACH:
232 * canqueue_ends_init_kern - Linux userspace clients specific ends initialization
233 * @qends: pointer to the callback side ends structure
235 int canqueue_ends_init_kern(struct canque_ends_t *qends)
237 canqueue_ends_init_gen(qends);
239 init_waitqueue_head(&qends->endinfo.fileinfo.readq);
240 init_waitqueue_head(&qends->endinfo.fileinfo.writeq);
241 init_waitqueue_head(&qends->endinfo.fileinfo.emptyq);
242 #ifdef CAN_ENABLE_KERN_FASYNC
243 qends->endinfo.fileinfo.fasync=NULL;
244 #endif /*CAN_ENABLE_KERN_FASYNC*/
246 qends->notify=canqueue_notify_kern;
247 DEBUGQUE("canqueue_ends_init_kern\n");
253 * canque_get_inslot4id_wait_kern - find or wait for best outgoing edge and slot for given ID
254 * @qends: ends structure belonging to calling communication object
255 * @qedgep: place to store pointer to found edge
256 * @slotp: place to store pointer to allocated slot
257 * @cmd: command type for slot
258 * @id: communication ID of message to send into edge
259 * @prio: optional priority of message
261 * Same as canque_get_inslot4id(), except, that it waits for free slot
262 * in case, that queue is full. Function is specific for Linux userspace clients.
263 * Return Value: If there is no usable edge negative value is returned.
265 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
266 struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
267 int cmd, unsigned long id, int prio)
270 DEBUGQUE("canque_get_inslot4id_wait_kern for cmd %d, id %ld, prio %d\n",cmd,id,prio);
271 wait_event_interruptible((qends->endinfo.fileinfo.writeq),
272 (ret=canque_get_inslot4id(qends,qedgep,slotp,cmd,id,prio))!=-1);
277 * canque_get_outslot_wait_kern - receive or wait for ready slot for given ends
278 * @qends: ends structure belonging to calling communication object
279 * @qedgep: place to store pointer to found edge
280 * @slotp: place to store pointer to received slot
282 * The same as canque_test_outslot(), except it waits in the case, that there is
283 * no ready slot for given ends. Function is specific for Linux userspace clients.
284 * Return Value: Negative value informs, that there is no ready output
285 * slot for given ends. Positive value is equal to the command
286 * slot has been allocated by the input side.
288 int canque_get_outslot_wait_kern(struct canque_ends_t *qends,
289 struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
292 DEBUGQUE("canque_get_outslot_wait_kern\n");
293 wait_event_interruptible((qends->endinfo.fileinfo.readq),
294 (ret=canque_test_outslot(qends,qedgep,slotp))!=-1);
299 * canque_sync_wait_kern - wait for all slots processing
300 * @qends: ends structure belonging to calling communication object
301 * @qedge: pointer to edge
303 * Functions waits for ends transition into empty state.
304 * Return Value: Positive value indicates, that edge empty state has been reached.
305 * Negative or zero value informs about interrupted wait or other problem.
307 int canque_sync_wait_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
310 DEBUGQUE("canque_sync_wait_kern\n");
311 wait_event_interruptible((qends->endinfo.fileinfo.emptyq),
312 (ret=canque_fifo_test_fl(&qedge->fifo,EMPTY)?1:0));
318 * canque_fifo_init_kern - initialize one CAN FIFO
319 * @fifo: pointer to the FIFO structure
320 * @slotsnr: number of requested slots
322 * Return Value: The negative value indicates, that there is no memory
323 * to allocate space for the requested number of the slots.
325 int canque_fifo_init_kern(struct canque_fifo_t *fifo, int slotsnr)
328 if(!slotsnr) slotsnr=MAX_BUF_LENGTH;
329 size=sizeof(struct canque_slot_t)*slotsnr;
330 fifo->entry=malloc(size);
331 if(!fifo->entry) return -1;
332 fifo->slotsnr=slotsnr;
333 return canque_fifo_init_slots(fifo);
337 * canque_fifo_done_kern - frees slots allocated for CAN FIFO
338 * @fifo: pointer to the FIFO structure
340 int canque_fifo_done_kern(struct canque_fifo_t *fifo)
350 * canque_new_edge_kern - allocate new edge structure in the Linux kernel context
351 * @slotsnr: required number of slots in the newly allocated edge structure
353 * Return Value: Returns pointer to allocated slot structure or %NULL if
354 * there is not enough memory to process operation.
356 struct canque_edge_t *canque_new_edge_kern(int slotsnr)
358 struct canque_edge_t *qedge;
359 qedge = (struct canque_edge_t *)malloc(sizeof(struct canque_edge_t));
360 if(qedge == NULL) return NULL;
362 memset(qedge,0,sizeof(struct canque_edge_t));
363 can_spin_lock_init(&qedge->fifo.fifo_lock);
364 if(canque_fifo_init_kern(&qedge->fifo, slotsnr)<0){
366 DEBUGQUE("canque_new_edge_kern failed\n");
369 atomic_set(&qedge->edge_used,1);
371 qedge->filtmask = canque_filtid2internal(0l, (processlocal<2)? MSG_LOCAL:0);
372 qedge->edge_prio = 0;
374 /* not exactly clean, but enough for debugging */
375 atomic_inc(&edge_num_cnt);
376 qedge->edge_num=atomic_read(&edge_num_cnt);
377 #endif /* CAN_DEBUG */
378 DEBUGQUE("canque_new_edge_kern %d\n",qedge->edge_num);
382 #ifdef USE_SYNC_DISCONNECT_EDGE_KERN
384 /*not included in doc
385 * canqueue_disconnect_edge_kern - disconnect edge from communicating entities with wait
386 * @qends: ends structure belonging to calling communication object
387 * @qedge: pointer to edge
389 * Same as canqueue_disconnect_edge(), but tries to wait for state with zero
391 * Return Value: Negative value means, that edge is used and cannot
392 * be disconnected yet. Operation has to be delayed.
394 int canqueue_disconnect_edge_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
396 canque_fifo_set_fl(&qedge->fifo,BLOCK);
397 DEBUGQUE("canqueue_disconnect_edge_kern %d called\n",qedge->edge_num);
398 if(!canque_fifo_test_and_set_fl(&qedge->fifo,DEAD)){
399 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_DEAD);
401 if(atomic_read(&qedge->edge_used)>0)
402 atomic_dec(&qedge->edge_used);
404 DEBUGQUE("canqueue_disconnect_edge_kern %d waiting\n",qedge->edge_num);
405 wait_event((qends->endinfo.fileinfo.emptyq),
406 (canqueue_disconnect_edge(qedge)>=0));
408 /*set_current_state(TASK_UNINTERRUPTIBLE);*/
409 /*schedule_timeout(HZ);*/
412 DEBUGQUE("canqueue_disconnect_edge_kern cannot set DEAD\n");
418 int canqueue_disconnect_list_kern(struct canque_ends_t *qends, struct list_head *list)
420 struct canque_edge_t *edge;
421 can_spin_irqflags_t flags;
423 can_spin_lock_irqsave(&qends->ends_lock,flags);
424 if(list_empty(list)){
425 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
428 if(list == &qends->inlist)
429 edge=list_entry(list->next,struct canque_edge_t,inpeers);
431 edge=list_entry(list->next,struct canque_edge_t,outpeers);
432 atomic_inc(&edge->edge_used);
433 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
434 if(canqueue_disconnect_edge_kern(qends, edge)>=0) {
435 /* Free edge memory */
436 canque_fifo_done_kern(&edge->fifo);
439 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
440 canque_edge_decref(edge);
441 DEBUGQUE("canqueue_disconnect_list_kern in troubles\n");
442 DEBUGQUE("the edge %d has usage count %d and flags %ld\n",edge->edge_num,atomic_read(&edge->edge_used),edge->fifo.fifo_flags);
448 #endif /*USE_SYNC_DISCONNECT_EDGE_KERN*/
451 int canqueue_ends_sync_all_kern(struct canque_ends_t *qends)
453 struct canque_edge_t *qedge;
455 canque_for_each_inedge(qends, qedge){
456 DEBUGQUE("canque_sync_wait_kern called for edge %d\n",qedge->edge_num);
457 canque_sync_wait_kern(qends, qedge);
463 void canqueue_ends_dispose_postpone(struct canque_ends_t *qends)
465 can_spin_irqflags_t flags;
467 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
468 qends->ends_flags |= CAN_ENDSF_DEAD;
469 list_add(&qends->dead_peers,&canque_dead_ends);
470 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
471 canque_dead_tasklet_schedule();
476 * canqueue_ends_dispose_kern - finalizing of the ends structure for Linux kernel clients
477 * @qends: pointer to ends structure
478 * @sync: flag indicating, that user wants to wait for processing of all remaining
481 * Return Value: Function should be designed such way to not fail.
483 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync)
487 DEBUGQUE("canqueue_ends_dispose_kern\n");
488 canqueue_block_inlist(qends);
489 canqueue_block_outlist(qends);
491 /*Wait for sending of all pending messages in the output FIFOs*/
493 canqueue_ends_sync_all_kern(qends);
495 /* Finish or kill all outgoing edges listed in inends */
496 delayed=canqueue_ends_kill_inlist(qends, 1);
497 /* Kill all incoming edges listed in outends */
498 delayed|=canqueue_ends_kill_outlist(qends);
500 wake_up(&qends->endinfo.fileinfo.readq);
501 wake_up(&qends->endinfo.fileinfo.writeq);
502 wake_up(&qends->endinfo.fileinfo.emptyq);
505 canqueue_ends_dispose_postpone(qends);
507 DEBUGQUE("canqueue_ends_dispose_kern delayed\n");
512 DEBUGQUE("canqueue_ends_dispose_kern finished\n");
516 void canqueue_kern_initialize()
518 can_spin_lock_init(&canque_dead_func_lock);