Correction of spinlock acquire order.

[lincan.git] / lincan / include / can_queue.h

diff --git a/lincan/include/can_queue.h b/lincan/include/can_queue.h
index 2fc422f4f38d080a294da19df4f7a752d9b7d2fa..3be84691cce7d0647c78051cbfc7bedd0911c002 100644 (file)
--- a/lincan/include/can_queue.h
+++ b/lincan/include/can_queue.h
@@ -1,7 +1,15 @@
+/* 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
 
 #ifndef _CAN_QUEUE_H
 #define _CAN_QUEUE_H
 

-#include "./can.h"
+#include "./canmsg.h"

 #include "./constants.h"
 #include "./can_sysdep.h"
 
 #include "./constants.h"
 #include "./can_sysdep.h"
 


@@ -39,6 +47,7 @@
  * @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.
  * @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.

+ * @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
  *
  * This structure represents CAN FIFO queue. It is implemented as 
  * a single linked list of slots prepared for processing. The empty slots


@@ -52,6 +61,7 @@ struct canque_fifo_t {
        struct canque_slot_t *flist;    /* points the first entry in the free list */
        struct canque_slot_t *entry;    /* points to first allocated entry */
        can_spinlock_t fifo_lock;       /* can_spin_lock_irqsave / can_spin_unlock_irqrestore */
        struct canque_slot_t *flist;    /* points the first entry in the free list */
        struct canque_slot_t *entry;    /* points to first allocated entry */
        can_spinlock_t fifo_lock;       /* can_spin_lock_irqsave / can_spin_unlock_irqrestore */

+       int    slotsnr;

 };
 
 #define CAN_FIFOF_DESTROY_b    15
 };
 
 #define CAN_FIFOF_DESTROY_b    15


@@ -65,6 +75,8 @@ struct canque_fifo_t {
 #define CAN_FIFOF_INACTIVE_b   7
 #define CAN_FIFOF_FREEONEMPTY_b        6
 #define CAN_FIFOF_READY_b      5
 #define CAN_FIFOF_INACTIVE_b   7
 #define CAN_FIFOF_FREEONEMPTY_b        6
 #define CAN_FIFOF_READY_b      5

+#define CAN_FIFOF_NOTIFYPEND_b 4
+#define CAN_FIFOF_RTL_MEM_b    3

 
 #define CAN_FIFOF_DESTROY      (1<<CAN_FIFOF_DESTROY_b)
 #define CAN_FIFOF_ERROR                (1<<CAN_FIFOF_ERROR_b)
 
 #define CAN_FIFOF_DESTROY      (1<<CAN_FIFOF_DESTROY_b)
 #define CAN_FIFOF_ERROR                (1<<CAN_FIFOF_ERROR_b)


@@ -77,6 +89,8 @@ struct canque_fifo_t {
 #define CAN_FIFOF_INACTIVE     (1<<CAN_FIFOF_INACTIVE_b)
 #define CAN_FIFOF_FREEONEMPTY  (1<<CAN_FIFOF_FREEONEMPTY_b)
 #define CAN_FIFOF_READY                (1<<CAN_FIFOF_READY_b)
 #define CAN_FIFOF_INACTIVE     (1<<CAN_FIFOF_INACTIVE_b)
 #define CAN_FIFOF_FREEONEMPTY  (1<<CAN_FIFOF_FREEONEMPTY_b)
 #define CAN_FIFOF_READY                (1<<CAN_FIFOF_READY_b)

+#define CAN_FIFOF_NOTIFYPEND    (1<<CAN_FIFOF_NOTIFYPEND_b)
+#define CAN_FIFOF_RTL_MEM       (1<<CAN_FIFOF_RTL_MEM_b)

 
 #define canque_fifo_test_fl(fifo,fifo_fl) \
   test_bit(CAN_FIFOF_##fifo_fl##_b,&(fifo)->fifo_flags)
 
 #define canque_fifo_test_fl(fifo,fifo_fl) \
   test_bit(CAN_FIFOF_##fifo_fl##_b,&(fifo)->fifo_flags)


@@ -137,7 +151,7 @@ int canque_fifo_put_inslot(struct canque_fifo_t *fifo, struct canque_slot_t *slo
        can_spin_irqflags_t flags;
        slot->next=NULL;
        can_spin_lock_irqsave(&fifo->fifo_lock, flags);
        can_spin_irqflags_t flags;
        slot->next=NULL;
        can_spin_lock_irqsave(&fifo->fifo_lock, flags);

-       if(*fifo->tail) printk(KERN_CRIT "canque_fifo_put_inslot: fifo->tail != NULL\n");
+       if(*fifo->tail) can_printk(KERN_CRIT "canque_fifo_put_inslot: fifo->tail != NULL\n");

        *fifo->tail=slot;
        fifo->tail=&slot->next;
        ret=0;
        *fifo->tail=slot;
        fifo->tail=&slot->next;
        ret=0;


@@ -253,9 +267,7 @@ int canque_fifo_again_outslot(struct canque_fifo_t *fifo, struct canque_slot_t *
 
 int canque_fifo_flush_slots(struct canque_fifo_t *fifo);
 
 
 int canque_fifo_flush_slots(struct canque_fifo_t *fifo);
 

-int canque_fifo_init_slots(struct canque_fifo_t *fifo, int slotsnr);
-
-int canque_fifo_done(struct canque_fifo_t *fifo);
+int canque_fifo_init_slots(struct canque_fifo_t *fifo);

 
 #define CANQUEUE_PRIO_NR  3
 
 
 #define CANQUEUE_PRIO_NR  3
 


@@ -281,6 +293,9 @@ struct chip_t;
  * @edge_used: the atomic usage counter, mainly used for safe destruction of the edge.
  * @edge_prio: the assigned queue priority from the range 0 to %CANQUEUE_PRIO_NR-1
  * @edge_num: edge sequential number intended for debugging purposes only
  * @edge_used: the atomic usage counter, mainly used for safe destruction of the edge.
  * @edge_prio: the assigned queue priority from the range 0 to %CANQUEUE_PRIO_NR-1
  * @edge_num: edge sequential number intended for debugging purposes only

+ * @pending_peers: edges with pending delayed events (RTL->Linux calls)
+ * @pending_inops: bitmask of pending operations
+ * @pending_outops: bitmask of pending operations

  *
  * This structure represents one direction connection from messages source 
  * (@inends) to message consumer (@outends) fifo ends hub. The edge contains
  *
  * This structure represents one direction connection from messages source 
  * (@inends) to message consumer (@outends) fifo ends hub. The edge contains


@@ -298,6 +313,11 @@ struct canque_edge_t {
        atomic_t edge_used;
        int edge_prio;
        int edge_num;
        atomic_t edge_used;
        int edge_prio;
        int edge_num;

+    #ifdef CAN_WITH_RTL
+       struct list_head pending_peers;
+       unsigned long pending_inops;
+       unsigned long pending_outops;
+    #endif /*CAN_WITH_RTL*/

 };
 
 /**
 };
 
 /**


@@ -307,6 +327,8 @@ struct canque_edge_t {
  *     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.
  *     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.
  * @ends_lock: the lock synchronizing operations between threads accessing
  *     same ends structure.
  * @notify: pointer to notify procedure. The next state changes are notified.


@@ -322,6 +344,7 @@ struct canque_edge_t {
  * @context: space to store ends user specific information
  * @endinfo: space to store some other ends usage specific informations
  *     mainly for waking-up by the notify calls.
  * @context: space to store ends user specific information
  * @endinfo: space to store some other ends usage specific informations
  *     mainly for waking-up by the notify calls.

+ * @dead_peers: used to chain ends wanting for postponed destruction

  *
  * Structure represents place to connect edges to for CAN communication entity.
  * The zero, one or more incoming and outgoing edges can be connected to
  *
  * Structure represents place to connect edges to for CAN communication entity.
  * The zero, one or more incoming and outgoing edges can be connected to


@@ -345,10 +368,26 @@ struct canque_ends_t {
                        struct fasync_struct *fasync;
                    #endif /*CAN_ENABLE_KERN_FASYNC*/
                } fileinfo;
                        struct fasync_struct *fasync;
                    #endif /*CAN_ENABLE_KERN_FASYNC*/
                } fileinfo;

+           #ifdef CAN_WITH_RTL
+               struct {
+                       rtl_spinlock_t rtl_lock;
+                       rtl_wait_t rtl_readq;
+                       atomic_t   rtl_readq_age;
+                       rtl_wait_t rtl_writeq;
+                       atomic_t   rtl_writeq_age;
+                       rtl_wait_t rtl_emptyq;
+                       atomic_t   rtl_emptyq_age;
+                       unsigned long pend_flags;
+               } rtlinfo;
+           #endif /*CAN_WITH_RTL*/

                struct {
                struct {

-                       wait_queue_head_t daemonq;

                        struct msgobj_t *msgobj;
                        struct chip_t *chip;
                        struct msgobj_t *msgobj;
                        struct chip_t *chip;

+                   #ifndef CAN_WITH_RTL
+                       wait_queue_head_t daemonq;
+                   #else /*CAN_WITH_RTL*/
+                       pthread_t worker_thread;
+                   #endif /*CAN_WITH_RTL*/

                } chipinfo;
        } endinfo;
        struct list_head dead_peers;
                } chipinfo;
        } endinfo;
        struct list_head dead_peers;


@@ -367,7 +406,8 @@ struct canque_ends_t {
 #define CANQUEUE_NOTIFY_ERRTX_SEND 0x11002 /* tx send error */
 #define CANQUEUE_NOTIFY_ERRTX_BUS  0x11003 /* tx bus error */
 
 #define CANQUEUE_NOTIFY_ERRTX_SEND 0x11002 /* tx send error */
 #define CANQUEUE_NOTIFY_ERRTX_BUS  0x11003 /* tx bus error */
 

-#define CAN_ENDSF_DEAD (1<<0)
+#define CAN_ENDSF_DEAD   (1<<0)
+#define CAN_ENDSF_MEM_RTL (1<<1)

 
 /**
  * canque_notify_inends - request to send notification to the input ends
 
 /**
  * canque_notify_inends - request to send notification to the input ends


@@ -413,7 +453,8 @@ void canque_notify_bothends(struct canque_edge_t *qedge, int what)
  * @inends: input side of the edge
  *
  * Function call moves output side of the edge from idle onto active edges
  * @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)
  */
 static inline
 void canque_activate_edge(struct canque_ends_t *inends, struct canque_edge_t *qedge)


@@ -422,19 +463,16 @@ void canque_activate_edge(struct canque_ends_t *inends, struct canque_edge_t *qe
        struct canque_ends_t *outends;
        if(qedge->edge_prio>=CANQUEUE_PRIO_NR)
                qedge->edge_prio=CANQUEUE_PRIO_NR-1;
        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)){
        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_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);

 }
 
 /**
 }
 
 /**


@@ -495,10 +533,20 @@ int canqueue_ends_kill_inlist(struct canque_ends_t *qends, int send_rest);
 
 int canqueue_ends_kill_outlist(struct canque_ends_t *qends);
 
 
 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 */
 
 /* 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_incref(struct canque_edge_t *edge)
 {


@@ -506,27 +554,79 @@ void canque_edge_incref(struct canque_edge_t *edge)
 }
 
 static inline
 }
 
 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;
 {
        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)) {
        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)
 
 static inline
 struct canque_edge_t *canque_first_inedge(struct canque_ends_t *qends)


@@ -636,6 +736,10 @@ struct canque_edge_t *canque_next_outedge(struct canque_ends_t *qends, struct ca
 
 /* Linux kernel specific functions */
 
 
 /* Linux kernel specific functions */
 

+int canque_fifo_init_kern(struct canque_fifo_t *fifo, int slotsnr);
+
+int canque_fifo_done_kern(struct canque_fifo_t *fifo);
+

 struct canque_edge_t *canque_new_edge_kern(int slotsnr);
 
 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,
 struct canque_edge_t *canque_new_edge_kern(int slotsnr);
 
 int canque_get_inslot4id_wait_kern(struct canque_ends_t *qends,


@@ -651,7 +755,53 @@ int canqueue_ends_init_kern(struct canque_ends_t *qends);
 
 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync);
 
 
 int canqueue_ends_dispose_kern(struct canque_ends_t *qends, int sync);
 

+void canqueue_ends_dispose_postpone(struct canque_ends_t *qends);
+

 void canqueue_kern_initialize(void);
 
 void canqueue_kern_initialize(void);
 

+#ifdef CAN_WITH_RTL
+
+extern struct tasklet_struct canque_dead_tl;   /*publication required only for RTL*/
+
+/* RT-Linux specific functions and variables */
+
+extern int canqueue_rtl_irq;
+
+extern unsigned long canqueue_rtl2lin_pend;
+
+#define CAN_RTL2LIN_PEND_DEAD_b 0
+
+void canqueue_rtl_initialize(void);
+void canqueue_rtl_done(void);
+
+int canqueue_rtl2lin_check_and_pend(struct canque_ends_t *qends,
+                        struct canque_edge_t *qedge, int what);
+
+struct canque_edge_t *canque_new_edge_rtl(int slotsnr);
+
+void canque_dispose_edge_rtl(struct canque_edge_t *qedge);
+
+int canque_get_inslot4id_wait_rtl(struct canque_ends_t *qends,
+       struct canque_edge_t **qedgep, struct canque_slot_t **slotp,
+       int cmd, unsigned long id, int prio);
+
+int canque_get_outslot_wait_rtl(struct canque_ends_t *qends,
+       struct canque_edge_t **qedgep, struct canque_slot_t **slotp);
+
+int canque_sync_wait_rtl(struct canque_ends_t *qends, struct canque_edge_t *qedge);
+
+void canque_ends_free_rtl(struct canque_ends_t *qends);
+
+int canqueue_ends_init_rtl(struct canque_ends_t *qends);
+
+int canqueue_ends_dispose_rtl(struct canque_ends_t *qends, int sync);
+
+#else /*CAN_WITH_RTL*/
+
+static inline int canqueue_rtl2lin_check_and_pend(struct canque_ends_t *qends,
+                       struct canque_edge_t *qedge, int what) { return 0; }
+
+#endif /*CAN_WITH_RTL*/
+

 
 #endif /*_CAN_QUEUE_H*/
 
 #endif /*_CAN_QUEUE_H*/