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-0.2 9 Jul 2003
9 #include "../include/can.h"
10 #include "../include/can_sysdep.h"
11 #include "../include/can_queue.h"
15 extern atomic_t edge_num_cnt;
18 #define DEBUGQUE(fmt,args...) can_printk(KERN_ERR "can_queue (debug): " fmt,\
22 #define DEBUGQUE(fmt,args...)
25 #define ERRMSGQUE(fmt,args...) can_printk(KERN_ERR "can_queue: " 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, int dead_fl)
127 can_spin_irqflags_t flags;
131 if(canqueue_disconnect_edge(edge)<0){
132 ERRMSGQUE("canque_edge_do_dead: canqueue_disconnect_edge failed !!!\n");
136 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
137 list_add(&edge->inpeers,&canque_dead_edges);
138 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
139 canque_dead_tasklet_schedule();
144 /*if(qends->ends_flags & CAN_ENDSF_DEAD){
145 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
146 list_del(&qends->dead_peers);
147 list_add(&qends->dead_peers,&canque_dead_ends);
148 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
149 tasklet_schedule(&canque_dead_tl);
154 * canqueue_notify_kern - notification callback handler for Linux userspace clients
155 * @qends: pointer to the callback side ends structure
156 * @qedge: edge which invoked notification
157 * @what: notification type
159 void canqueue_notify_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge, int what)
161 DEBUGQUE("canqueue_notify_kern for edge %d, use %d and event %d\n",
162 qedge->edge_num,(int)atomic_read(&qedge->edge_used),what);
164 /* delay event delivery for RT-Linux -> kernel notifications */
165 if(canqueue_rtl2lin_check_and_pend(qends,qedge,what)){
166 DEBUGQUE("canqueue_notify_kern postponed\n");
171 case CANQUEUE_NOTIFY_EMPTY:
172 wake_up(&qends->endinfo.fileinfo.emptyq);
173 if(canque_fifo_test_and_clear_fl(&qedge->fifo, FREEONEMPTY))
174 canque_edge_decref(qedge);
176 case CANQUEUE_NOTIFY_SPACE:
177 wake_up(&qends->endinfo.fileinfo.writeq);
178 #ifdef CAN_ENABLE_KERN_FASYNC
179 /* Asynchronous I/O processing */
180 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_OUT);
181 #endif /*CAN_ENABLE_KERN_FASYNC*/
183 case CANQUEUE_NOTIFY_PROC:
184 wake_up(&qends->endinfo.fileinfo.readq);
185 #ifdef CAN_ENABLE_KERN_FASYNC
186 /* Asynchronous I/O processing */
187 kill_fasync(&qends->endinfo.fileinfo.fasync, SIGIO, POLL_IN);
188 #endif /*CAN_ENABLE_KERN_FASYNC*/
190 case CANQUEUE_NOTIFY_NOUSR:
191 wake_up(&qends->endinfo.fileinfo.readq);
192 wake_up(&qends->endinfo.fileinfo.writeq);
193 wake_up(&qends->endinfo.fileinfo.emptyq);
195 case CANQUEUE_NOTIFY_DEAD_WANTED:
196 case CANQUEUE_NOTIFY_DEAD:
197 if(canque_fifo_test_and_clear_fl(&qedge->fifo, READY))
198 canque_edge_decref(qedge);
200 case CANQUEUE_NOTIFY_ATTACH:
206 * canqueue_ends_init_kern - Linux userspace clients specific ends initialization
207 * @qends: pointer to the callback side ends structure
209 int canqueue_ends_init_kern(struct canque_ends_t *qends)
211 canqueue_ends_init_gen(qends);
213 init_waitqueue_head(&qends->endinfo.fileinfo.readq);
214 init_waitqueue_head(&qends->endinfo.fileinfo.writeq);
215 init_waitqueue_head(&qends->endinfo.fileinfo.emptyq);
216 #ifdef CAN_ENABLE_KERN_FASYNC
217 qends->endinfo.fileinfo.fasync=NULL;
218 #endif /*CAN_ENABLE_KERN_FASYNC*/
220 qends->notify=canqueue_notify_kern;
221 DEBUGQUE("canqueue_ends_init_kern\n");
227 * canque_get_inslot4id_wait_kern - find or wait for best outgoing edge and slot for given ID
228 * @qends: ends structure belonging to calling communication object
229 * @qedgep: place to store pointer to found edge
230 * @slotp: place to store pointer to allocated slot
231 * @cmd: command type for slot
232 * @id: communication ID of message to send into edge
233 * @prio: optional priority of message
235 * Same as canque_get_inslot4id(), except, that it waits for free slot
236 * in case, that queue is full. Function is specific for Linux userspace clients.
237 * Return Value: If there is no usable edge negative value is returned.
239 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
240 struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
241 int cmd, unsigned long id, int prio)
244 DEBUGQUE("canque_get_inslot4id_wait_kern for cmd %d, id %ld, prio %d\n",cmd,id,prio);
245 wait_event_interruptible((qends->endinfo.fileinfo.writeq),
246 (ret=canque_get_inslot4id(qends,qedgep,slotp,cmd,id,prio))!=-1);
251 * canque_get_outslot_wait_kern - receive or wait for ready slot for given ends
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 received slot
256 * The same as canque_test_outslot(), except it waits in the case, that there is
257 * no ready slot for given ends. Function is specific for Linux userspace clients.
258 * Return Value: Negative value informs, that there is no ready output
259 * slot for given ends. Positive value is equal to the command
260 * slot has been allocated by the input side.
262 int canque_get_outslot_wait_kern(struct canque_ends_t *qends,
263 struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
266 DEBUGQUE("canque_get_outslot_wait_kern\n");
267 wait_event_interruptible((qends->endinfo.fileinfo.readq),
268 (ret=canque_test_outslot(qends,qedgep,slotp))!=-1);
273 * canque_sync_wait_kern - wait for all slots processing
274 * @qends: ends structure belonging to calling communication object
275 * @qedge: pointer to edge
277 * Functions waits for ends transition into empty state.
278 * Return Value: Positive value indicates, that edge empty state has been reached.
279 * Negative or zero value informs about interrupted wait or other problem.
281 int canque_sync_wait_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
284 DEBUGQUE("canque_sync_wait_kern\n");
285 wait_event_interruptible((qends->endinfo.fileinfo.emptyq),
286 (ret=canque_fifo_test_fl(&qedge->fifo,EMPTY)?1:0));
292 * canque_fifo_init_kern - initialize one CAN FIFO
293 * @fifo: pointer to the FIFO structure
294 * @slotsnr: number of requested slots
296 * Return Value: The negative value indicates, that there is no memory
297 * to allocate space for the requested number of the slots.
299 int canque_fifo_init_kern(struct canque_fifo_t *fifo, int slotsnr)
302 if(!slotsnr) slotsnr=MAX_BUF_LENGTH;
303 size=sizeof(struct canque_slot_t)*slotsnr;
304 fifo->entry=kmalloc(size,GFP_KERNEL);
305 if(!fifo->entry) return -1;
306 fifo->slotsnr=slotsnr;
307 return canque_fifo_init_slots(fifo);
311 * canque_fifo_done_kern - frees slots allocated for CAN FIFO
312 * @fifo: pointer to the FIFO structure
314 int canque_fifo_done_kern(struct canque_fifo_t *fifo)
324 * canque_new_edge_kern - allocate new edge structure in the Linux kernel context
325 * @slotsnr: required number of slots in the newly allocated edge structure
327 * Return Value: Returns pointer to allocated slot structure or %NULL if
328 * there is not enough memory to process operation.
330 struct canque_edge_t *canque_new_edge_kern(int slotsnr)
332 struct canque_edge_t *qedge;
333 qedge = (struct canque_edge_t *)kmalloc(sizeof(struct canque_edge_t), GFP_KERNEL);
334 if(qedge == NULL) return NULL;
336 memset(qedge,0,sizeof(struct canque_edge_t));
337 can_spin_lock_init(&qedge->fifo.fifo_lock);
338 if(canque_fifo_init_kern(&qedge->fifo, slotsnr)<0){
340 DEBUGQUE("canque_new_edge_kern failed\n");
343 atomic_set(&qedge->edge_used,1);
345 qedge->filtmask = canque_filtid2internal(0l, (processlocal<2)? MSG_LOCAL:0);
346 qedge->edge_prio = 0;
348 /* not exactly clean, but enough for debugging */
349 atomic_inc(&edge_num_cnt);
350 qedge->edge_num=atomic_read(&edge_num_cnt);
351 #endif /* CAN_DEBUG */
352 DEBUGQUE("canque_new_edge_kern %d\n",qedge->edge_num);
356 #ifdef USE_SYNC_DISCONNECT_EDGE_KERN
359 * canqueue_disconnect_edge_kern - disconnect edge from communicating entities with wait
360 * @qends: ends structure belonging to calling communication object
361 * @qedge: pointer to edge
363 * Same as canqueue_disconnect_edge(), but tries to wait for state with zero
365 * Return Value: Negative value means, that edge is used and cannot
366 * be disconnected yet. Operation has to be delayed.
368 int canqueue_disconnect_edge_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
370 canque_fifo_set_fl(&qedge->fifo,BLOCK);
371 DEBUGQUE("canqueue_disconnect_edge_kern %d called\n",qedge->edge_num);
372 if(!canque_fifo_test_and_set_fl(&qedge->fifo,DEAD)){
373 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_DEAD);
375 if(atomic_read(&qedge->edge_used)>0)
376 atomic_dec(&qedge->edge_used);
378 DEBUGQUE("canqueue_disconnect_edge_kern %d waiting\n",qedge->edge_num);
379 wait_event((qends->endinfo.fileinfo.emptyq),
380 (canqueue_disconnect_edge(qedge)>=0));
382 /*set_current_state(TASK_UNINTERRUPTIBLE);*/
383 /*schedule_timeout(HZ);*/
386 DEBUGQUE("canqueue_disconnect_edge_kern cannot set DEAD\n");
392 int canqueue_disconnect_list_kern(struct canque_ends_t *qends, struct list_head *list)
394 struct canque_edge_t *edge;
395 can_spin_irqflags_t flags;
397 can_spin_lock_irqsave(&qends->ends_lock,flags);
398 if(list_empty(list)){
399 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
402 if(list == &qends->inlist)
403 edge=list_entry(list->next,struct canque_edge_t,inpeers);
405 edge=list_entry(list->next,struct canque_edge_t,outpeers);
406 atomic_inc(&edge->edge_used);
407 can_spin_unlock_irqrestore(&qends->ends_lock,flags);
408 if(canqueue_disconnect_edge_kern(qends, edge)>=0) {
409 /* Free edge memory */
410 canque_fifo_done_kern(&edge->fifo);
413 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
414 canque_edge_decref(edge);
415 DEBUGQUE("canqueue_disconnect_list_kern in troubles\n");
416 DEBUGQUE("the edge %d has usage count %d and flags %ld\n",edge->edge_num,atomic_read(&edge->edge_used),edge->fifo.fifo_flags);
422 #endif /*USE_SYNC_DISCONNECT_EDGE_KERN*/
425 int canqueue_ends_sync_all_kern(struct canque_ends_t *qends)
427 struct canque_edge_t *qedge;
429 canque_for_each_inedge(qends, qedge){
430 DEBUGQUE("canque_sync_wait_kern called for edge %d\n",qedge->edge_num);
431 canque_sync_wait_kern(qends, qedge);
437 void canqueue_ends_dispose_postpone(struct canque_ends_t *qends)
439 can_spin_irqflags_t flags;
441 can_spin_lock_irqsave(&canque_dead_func_lock, flags);
442 qends->ends_flags |= CAN_ENDSF_DEAD;
443 list_add(&qends->dead_peers,&canque_dead_ends);
444 can_spin_unlock_irqrestore(&canque_dead_func_lock, flags);
445 canque_dead_tasklet_schedule();
450 * canqueue_ends_dispose_kern - finalizing of the ends structure for Linux kernel clients
451 * @qends: pointer to ends structure
452 * @sync: flag indicating, that user wants to wait for processing of all remaining
455 * Return Value: Function should be designed such way to not fail.
457 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync)
461 DEBUGQUE("canqueue_ends_dispose_kern\n");
462 canqueue_block_inlist(qends);
463 canqueue_block_outlist(qends);
465 /*Wait for sending of all pending messages in the output FIFOs*/
467 canqueue_ends_sync_all_kern(qends);
469 /* Finish or kill all outgoing edges listed in inends */
470 delayed=canqueue_ends_kill_inlist(qends, 1);
471 /* Kill all incoming edges listed in outends */
472 delayed|=canqueue_ends_kill_outlist(qends);
474 wake_up(&qends->endinfo.fileinfo.readq);
475 wake_up(&qends->endinfo.fileinfo.writeq);
476 wake_up(&qends->endinfo.fileinfo.emptyq);
479 canqueue_ends_dispose_postpone(qends);
481 DEBUGQUE("canqueue_ends_dispose_kern delayed\n");
486 DEBUGQUE("canqueue_ends_dispose_kern finished\n");
490 void canqueue_kern_initialize()
492 can_spin_lock_init(&canque_dead_func_lock);