+/* can_queue.h - CAN queues and message passing infrastructure
+ * Linux CAN-bus device driver.
+ * Written by Pavel Pisa - OCERA team member
+ * email:pisa@cmp.felk.cvut.cz
+ * This software is released under the GPL-License.
+ * Version lincan-0.3 17 Jun 2004
+ */
+
#ifndef _CAN_QUEUE_H
#define _CAN_QUEUE_H
-#include "./can.h"
+#include "./canmsg.h"
#include "./constants.h"
#include "./can_sysdep.h"
* @flist: pointer to list of the free slots associated with queue
* @entry: pointer to the memory allocated for the list slots.
* @fifo_lock: the lock to ensure atomicity of slot manipulation operations.
- * @slotnr: number of allocated slots
+ * @slotsnr: number of allocated slots
*
* This structure represents CAN FIFO queue. It is implemented as
* a single linked list of slots prepared for processing. The empty slots
* with ready messages. The array is indexed by the edges priorities.
* @idle: the list of the edges directed to the ends structure with empty FIFOs.
* @inlist: the list of outgoing edges input sides.
+ * @outlist: the list of all incoming edges output sides. Each of there edges
+ * is listed on one of @active or @idle lists.
* @ends_lock: the lock synchronizing operations between threads accessing
* same ends structure.
* @notify: pointer to notify procedure. The next state changes are notified.
* @inends: input side of the edge
*
* Function call moves output side of the edge from idle onto active edges
- * list.
+ * list. This function has to be called with edge reference count held.
+ * that is same as for most of other edge functions.
*/
static inline
void canque_activate_edge(struct canque_ends_t *inends, struct canque_edge_t *qedge)
struct canque_ends_t *outends;
if(qedge->edge_prio>=CANQUEUE_PRIO_NR)
qedge->edge_prio=CANQUEUE_PRIO_NR-1;
- can_spin_lock_irqsave(&inends->ends_lock, flags);
if((outends=qedge->outends)){
- can_spin_lock(&outends->ends_lock);
+ can_spin_lock_irqsave(&outends->ends_lock, flags);
can_spin_lock(&qedge->fifo.fifo_lock);
if(!canque_fifo_test_fl(&qedge->fifo,EMPTY)){
list_del(&qedge->activepeers);
list_add_tail(&qedge->activepeers,&outends->active[qedge->edge_prio]);
}
can_spin_unlock(&qedge->fifo.fifo_lock);
- can_spin_unlock(&outends->ends_lock);
-
+ can_spin_unlock_irqrestore(&outends->ends_lock, flags);
}
- can_spin_unlock_irqrestore(&inends->ends_lock, flags);
}
/**
int canqueue_ends_kill_outlist(struct canque_ends_t *qends);
+int canqueue_ends_filt_conjuction(struct canque_ends_t *qends, struct canfilt_t *filt);
+
+int canqueue_ends_flush_inlist(struct canque_ends_t *qends);
+
+int canqueue_ends_flush_outlist(struct canque_ends_t *qends);
+
/* edge reference and traversal functions */
-void canque_edge_do_dead(struct canque_edge_t *edge, int dead_fl);
+void canque_edge_do_dead(struct canque_edge_t *edge);
+/**
+ * canque_edge_incref - increments edge reference count
+ * @qedg: pointer to the edge structure
+ */
static inline
void canque_edge_incref(struct canque_edge_t *edge)
{
}
static inline
-void canque_edge_decref(struct canque_edge_t *edge)
+can_spin_irqflags_t canque_edge_lock_both_ends(struct canque_edge_t *edge)
+{
+ can_spin_irqflags_t flags;
+ if(edge->inends<edge->outends) {
+ can_spin_lock_irqsave(&edge->inends->ends_lock, flags);
+ can_spin_lock(&edge->outends->ends_lock);
+ }else{
+ can_spin_lock_irqsave(&edge->outends->ends_lock, flags);
+ if(edge->outends!=edge->inends) can_spin_lock(&edge->inends->ends_lock);
+ }
+ return flags;
+}
+
+static inline
+void canque_edge_unlock_both_ends(struct canque_edge_t *edge, can_spin_irqflags_t flags)
+{
+ if(edge->outends!=edge->inends) can_spin_unlock(&edge->outends->ends_lock);
+ can_spin_unlock_irqrestore(&edge->inends->ends_lock, flags);
+}
+
+/* Non-inlined version of edge reference decrement */
+void __canque_edge_decref(struct canque_edge_t *edge);
+
+static inline
+void __canque_edge_decref_body(struct canque_edge_t *edge)
{
can_spin_irqflags_t flags;
- struct canque_ends_t *inends=edge->inends;
- struct canque_ends_t *outends=edge->outends;
- int dead_fl;
+ int dead_fl=0;
- can_spin_lock_irqsave(&inends->ends_lock, flags);
- can_spin_lock(&outends->ends_lock);
+ flags=canque_edge_lock_both_ends(edge);
if(atomic_dec_and_test(&edge->edge_used)) {
- dead_fl=canque_fifo_test_and_set_fl(&edge->fifo,DEAD);
- /*This should not be there, but it cannot be outside of the lock :-(*/
- canque_notify_bothends(edge,CANQUEUE_NOTIFY_NOUSR);
- can_spin_unlock(&outends->ends_lock);
- can_spin_unlock_irqrestore(&inends->ends_lock, flags);
- canque_edge_do_dead(edge, dead_fl);
- } else {
- can_spin_unlock(&outends->ends_lock);
- can_spin_unlock_irqrestore(&inends->ends_lock, flags);
+ dead_fl=!canque_fifo_test_and_set_fl(&edge->fifo,DEAD);
+ /* Because of former evolution of edge references
+ management notify of CANQUEUE_NOTIFY_NOUSR could
+ be moved to canque_edge_do_dead :-) */
}
+ canque_edge_unlock_both_ends(edge, flags);
+ if(dead_fl) canque_edge_do_dead(edge);
+}
+
+#ifndef CAN_HAVE_ARCH_CMPXCHG
+/**
+ * canque_edge_decref - decrements edge reference count
+ * @qedg: pointer to the edge structure
+ *
+ * This function has to be called without lock held for both ends of edge.
+ * If reference count drops to 0, function canque_edge_do_dead()
+ * is called.
+ */
+static inline
+void canque_edge_decref(struct canque_edge_t *edge)
+{
+ __canque_edge_decref_body(edge);
+}
+#else
+static inline
+void canque_edge_decref(struct canque_edge_t *edge)
+{
+ int x, y;
+
+ x = atomic_read(&edge->edge_used);
+ do{
+ if(x<=1)
+ return __canque_edge_decref(edge);
+ y=x;
+ /* This code strongly depends on the definition of atomic_t !!!! */
+ /* x=cmpxchg(&edge->edge_used, x, x-1); */
+ /* Next alternative could be more portable */
+ x=__cmpxchg(&edge->edge_used, x, x-1, sizeof(atomic_t));
+ /* If even this does not help, comment out CAN_HAVE_ARCH_CMPXCHG in can_sysdep.h */
+ } while(x!=y);
}
+#endif
static inline
struct canque_edge_t *canque_first_inedge(struct canque_ends_t *qends)
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