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...) printk(KERN_ERR "can_queue (debug): " fmt,\
22 #define DEBUGQUE(fmt,args...)
25 #define ERRMSGQUE(fmt,args...) 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 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)
53 struct canque_edge_t *edge;
54 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 spin_unlock_irqrestore(&canque_dead_func_lock, flags);
65 void canque_dead_func(unsigned long data)
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);
77 spin_lock_irqsave(&canque_dead_func_lock, flags);
78 entry=canque_dead_ends.next;
79 spin_unlock_irqrestore(&canque_dead_func_lock,flags);
80 while(entry!=&canque_dead_ends){
81 qends=list_entry(canque_dead_ends.next,struct canque_ends_t,dead_peers);
83 if(!list_empty(&qends->inlist))
85 if(!list_empty(&qends->outlist))
87 spin_lock_irqsave(&canque_dead_func_lock, flags);
88 list_del(&qends->dead_peers);
89 spin_unlock_irqrestore(&canque_dead_func_lock,flags);
90 DEBUGQUE("ends structure disposed\n");
97 void canque_edge_do_dead(struct canque_edge_t *edge, int dead_fl)
103 if(canqueue_disconnect_edge(edge)<0){
104 ERRMSGQUE("canque_edge_do_dead: canqueue_disconnect_edge failed !!!\n");
108 spin_lock_irqsave(&canque_dead_func_lock, flags);
109 list_add(&edge->inpeers,&canque_dead_edges);
110 spin_unlock_irqrestore(&canque_dead_func_lock, flags);
111 tasklet_schedule(&canque_dead_tl);
116 /*if(qends->ends_flags & CAN_ENDSF_DEAD){
117 spin_lock_irqsave(&canque_dead_func_lock, flags);
118 list_del(&qends->dead_peers);
119 list_add(&qends->dead_peers,&canque_dead_ends);
120 spin_unlock_irqrestore(&canque_dead_func_lock, flags);
121 tasklet_schedule(&canque_dead_tl);
126 * canqueue_notify_kern - notification callback handler for Linux userspace clients
127 * @qends: pointer to the callback side ends structure
128 * @qedge: edge which invoked notification
129 * @what: notification type
131 void canqueue_notify_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge, int what)
133 DEBUGQUE("canqueue_notify_kern for edge %d, use %d and event %d\n",
134 qedge->edge_num,(int)atomic_read(&qedge->edge_used),what);
136 case CANQUEUE_NOTIFY_EMPTY:
137 wake_up(&qends->endinfo.fileinfo.emptyq);
138 if(canque_fifo_test_and_clear_fl(&qedge->fifo, FREEONEMPTY))
139 canque_edge_decref(qedge);
141 case CANQUEUE_NOTIFY_SPACE:
142 wake_up(&qends->endinfo.fileinfo.writeq);
144 case CANQUEUE_NOTIFY_PROC:
145 wake_up(&qends->endinfo.fileinfo.readq);
147 case CANQUEUE_NOTIFY_NOUSR:
148 wake_up(&qends->endinfo.fileinfo.readq);
149 wake_up(&qends->endinfo.fileinfo.writeq);
150 wake_up(&qends->endinfo.fileinfo.emptyq);
152 case CANQUEUE_NOTIFY_DEAD_WANTED:
153 case CANQUEUE_NOTIFY_DEAD:
154 if(canque_fifo_test_and_clear_fl(&qedge->fifo, READY))
155 canque_edge_decref(qedge);
157 case CANQUEUE_NOTIFY_ATTACH:
163 * canqueue_ends_init_kern - Linux userspace clients specific ends initialization
164 * @qends: pointer to the callback side ends structure
166 int canqueue_ends_init_kern(struct canque_ends_t *qends)
168 canqueue_ends_init_gen(qends);
170 init_waitqueue_head(&qends->endinfo.fileinfo.readq);
171 init_waitqueue_head(&qends->endinfo.fileinfo.writeq);
172 init_waitqueue_head(&qends->endinfo.fileinfo.emptyq);
173 qends->notify=canqueue_notify_kern;
174 DEBUGQUE("canqueue_ends_init_kern\n");
180 * canque_get_inslot4id_wait_kern - find or wait for best outgoing edge and slot for given ID
181 * @qends: ends structure belonging to calling communication object
182 * @qedgep: place to store pointer to found edge
183 * @slotp: place to store pointer to allocated slot
184 * @cmd: command type for slot
185 * @id: communication ID of message to send into edge
186 * @prio: optional priority of message
188 * Same as canque_get_inslot4id(), except, that it waits for free slot
189 * in case, that queue is full. Function is specific for Linux userspace clients.
190 * Return Value: If there is no usable edge negative value is returned.
192 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
193 struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
194 int cmd, unsigned long id, int prio)
197 DEBUGQUE("canque_get_inslot4id_wait_kern for cmd %d, id %ld, prio %d\n",cmd,id,prio);
198 wait_event_interruptible((qends->endinfo.fileinfo.writeq),
199 (ret=canque_get_inslot4id(qends,qedgep,slotp,cmd,id,prio))!=-1);
204 * canque_get_outslot_wait_kern - receive or wait for ready slot for given ends
205 * @qends: ends structure belonging to calling communication object
206 * @qedgep: place to store pointer to found edge
207 * @slotp: place to store pointer to received slot
209 * The same as canque_test_outslot(), except it waits in the case, that there is
210 * no ready slot for given ends. Function is specific for Linux userspace clients.
211 * Return Value: Negative value informs, that there is no ready output
212 * slot for given ends. Positive value is equal to the command
213 * slot has been allocated by the input side.
215 int canque_get_outslot_wait_kern(struct canque_ends_t *qends,
216 struct canque_edge_t **qedgep, struct canque_slot_t **slotp)
219 DEBUGQUE("canque_get_outslot_wait_kern\n");
220 wait_event_interruptible((qends->endinfo.fileinfo.readq),
221 (ret=canque_test_outslot(qends,qedgep,slotp))!=-1);
226 * canque_sync_wait_kern - wait for all slots processing
227 * @qends: ends structure belonging to calling communication object
228 * @qedge: pointer to edge
230 * Functions waits for ends transition into empty state.
231 * Return Value: Positive value indicates, that edge empty state has been reached.
232 * Negative or zero value informs about interrupted wait or other problem.
234 int canque_sync_wait_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
237 DEBUGQUE("canque_sync_wait_kern\n");
238 wait_event_interruptible((qends->endinfo.fileinfo.emptyq),
239 (ret=canque_fifo_test_fl(&qedge->fifo,EMPTY)?1:0));
245 * canque_new_edge_kern - allocate new edge structure in the Linux kernel context
246 * @slotsnr: required number of slots in the newly allocated edge structure
248 * Return Value: Returns pointer to allocated slot structure or %NULL if
249 * there is not enough memory to process operation.
251 struct canque_edge_t *canque_new_edge_kern(int slotsnr)
253 struct canque_edge_t *qedge;
254 qedge = (struct canque_edge_t *)kmalloc(sizeof(struct canque_edge_t), GFP_KERNEL);
255 if(qedge == NULL) return NULL;
257 memset(qedge,0,sizeof(struct canque_edge_t));
258 spin_lock_init(&qedge->fifo.fifo_lock);
259 if(canque_fifo_init_slots(&qedge->fifo, slotsnr)<0){
261 DEBUGQUE("canque_new_edge_kern failed\n");
264 atomic_set(&qedge->edge_used,1);
266 qedge->filtmask = canque_filtid2internal(0l, (processlocal<2)? MSG_LOCAL:0);
267 qedge->edge_prio = 0;
269 /* not exactly clean, but enough for debugging */
270 atomic_inc(&edge_num_cnt);
271 qedge->edge_num=atomic_read(&edge_num_cnt);
272 #endif /* CAN_DEBUG */
273 DEBUGQUE("canque_new_edge_kern %d\n",qedge->edge_num);
277 #ifdef USE_DELAYED_DISCONNECT_EDGE_KERN
280 * canqueue_disconnect_edge_kern - disconnect edge from communicating entities with wait
281 * @qends: ends structure belonging to calling communication object
282 * @qedge: pointer to edge
284 * Same as canqueue_disconnect_edge(), but tries to wait for state with zero
286 * Return Value: Negative value means, that edge is used and cannot
287 * be disconnected yet. Operation has to be delayed.
289 int canqueue_disconnect_edge_kern(struct canque_ends_t *qends, struct canque_edge_t *qedge)
291 canque_fifo_set_fl(&qedge->fifo,BLOCK);
292 DEBUGQUE("canqueue_disconnect_edge_kern %d called\n",qedge->edge_num);
293 if(!canque_fifo_test_and_set_fl(&qedge->fifo,DEAD)){
294 canque_notify_bothends(qedge, CANQUEUE_NOTIFY_DEAD);
296 if(atomic_read(&qedge->edge_used)>0)
297 atomic_dec(&qedge->edge_used);
299 DEBUGQUE("canqueue_disconnect_edge_kern %d waiting\n",qedge->edge_num);
300 wait_event((qends->endinfo.fileinfo.emptyq),
301 (canqueue_disconnect_edge(qedge)>=0));
303 /*set_current_state(TASK_UNINTERRUPTIBLE);*/
304 /*schedule_timeout(HZ);*/
307 DEBUGQUE("canqueue_disconnect_edge_kern cannot set DEAD\n");
313 int canqueue_disconnect_list_kern(struct canque_ends_t *qends, struct list_head *list)
315 struct canque_edge_t *edge;
318 spin_lock_irqsave(&qends->ends_lock,flags);
319 if(list_empty(list)){
320 spin_unlock_irqrestore(&qends->ends_lock,flags);
323 if(list == &qends->inlist)
324 edge=list_entry(list->next,struct canque_edge_t,inpeers);
326 edge=list_entry(list->next,struct canque_edge_t,outpeers);
327 atomic_inc(&edge->edge_used);
328 spin_unlock_irqrestore(&qends->ends_lock,flags);
329 if(canqueue_disconnect_edge_kern(qends, edge)>=0) {
330 /* Free edge memory */
331 canque_fifo_done(&edge->fifo);
334 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
335 canque_edge_decref(edge);
336 DEBUGQUE("canqueue_disconnect_list_kern in troubles\n");
337 DEBUGQUE("the edge %d has usage count %d and flags %ld\n",edge->edge_num,atomic_read(&edge->edge_used),edge->fifo.fifo_flags);
343 #endif /*USE_DELAYED_DISCONNECT_EDGE_KERN*/
346 int canqueue_ends_sync_all_kern(struct canque_ends_t *qends)
348 struct canque_edge_t *qedge;
350 canque_for_each_inedge(qends, qedge){
351 DEBUGQUE("canque_sync_wait_kern called for edge %d\n",qedge->edge_num);
352 canque_sync_wait_kern(qends, qedge);
357 int canqueue_ends_done_inends(struct canque_ends_t *qends, int send_rest)
359 struct canque_edge_t *edge;
361 canque_for_each_inedge(qends, edge){
362 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
364 canque_edge_incref(edge);
365 if(!canque_fifo_test_and_set_fl(&edge->fifo, FREEONEMPTY)){
366 if(!canque_fifo_test_fl(&edge->fifo, EMPTY))
368 if(!canque_fifo_test_and_clear_fl(&edge->fifo, FREEONEMPTY))
371 canque_edge_decref(edge);
374 return list_empty(&qends->inlist)?0:1;
378 int canqueue_ends_done_outends(struct canque_ends_t *qends)
380 struct canque_edge_t *edge;
382 canque_for_each_outedge(qends, edge){
383 canque_notify_bothends(edge, CANQUEUE_NOTIFY_DEAD_WANTED);
385 return list_empty(&qends->outlist)?0:1;
390 * canqueue_ends_dispose_kern - finalizing of the ends structure for Linux kernel clients
391 * @qends: pointer to ends structure
392 * @sync: flag indicating, that user wants to wait for processing of all remaining
395 * Return Value: Function should be designed such way to not fail.
397 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync)
402 DEBUGQUE("canqueue_ends_dispose_kern\n");
403 canqueue_block_inlist(qends);
404 canqueue_block_outlist(qends);
406 /*Wait for sending of all pending messages in the output FIFOs*/
408 canqueue_ends_sync_all_kern(qends);
410 /* Finish all outgoing edges listed in inends */
411 delayed=canqueue_ends_done_inends(qends, 1);
413 delayed|=canqueue_ends_done_outends(qends);
415 wake_up(&qends->endinfo.fileinfo.readq);
416 wake_up(&qends->endinfo.fileinfo.writeq);
417 wake_up(&qends->endinfo.fileinfo.emptyq);
420 spin_lock_irqsave(&canque_dead_func_lock, flags);
421 qends->ends_flags |= CAN_ENDSF_DEAD;
422 list_add(&qends->dead_peers,&canque_dead_ends);
423 spin_unlock_irqrestore(&canque_dead_func_lock, flags);
424 tasklet_schedule(&canque_dead_tl);
426 DEBUGQUE("canqueue_ends_dispose_kern delayed\n");
431 DEBUGQUE("canqueue_ends_dispose_kern finished\n");
435 void canqueue_kern_initialize()