drivers/s390/net/fsm.h

   1 /* $Id: fsm.h,v 1.1.1.1 2002/03/13 19:33:09 mschwide Exp $
   2  */
   3 #ifndef _FSM_H_
   4 #define _FSM_H_
   5
   6 #include <linux/kernel.h>
   7 #include <linux/types.h>
   8 #include <linux/timer.h>
   9 #include <linux/time.h>
  10 #include <linux/slab.h>
  11 #include <linux/sched.h>
  12 #include <linux/string.h>
  13 #include <asm/atomic.h>
  14
  15 /**
  16  * Define this to get debugging messages.
  17  */
  18 #define FSM_DEBUG         0
  19
  20 /**
  21  * Define this to get debugging massages for
  22  * timer handling.
  23  */
  24 #define FSM_TIMER_DEBUG   0
  25
  26 /**
  27  * Define these to record a history of
  28  * Events/Statechanges and print it if a
  29  * action_function is not found.
  30  */
  31 #define FSM_DEBUG_HISTORY 0
  32 #define FSM_HISTORY_SIZE  40
  33
  34 struct fsm_instance_t;
  35
  36 /**
  37  * Definition of an action function, called by a FSM
  38  */
  39 typedef void (*fsm_function_t)(struct fsm_instance_t *, int, void *);
  40
  41 /**
  42  * Internal jump table for a FSM
  43  */
  44 typedef struct {
  45         fsm_function_t *jumpmatrix;
  46         int nr_events;
  47         int nr_states;
  48         const char **event_names;
  49         const char **state_names;
  50 } fsm;
  51
  52 #if FSM_DEBUG_HISTORY
  53 /**
  54  * Element of State/Event history used for debugging.
  55  */
  56 typedef struct {
  57         int state;
  58         int event;
  59 } fsm_history;
  60 #endif
  61
  62 /**
  63  * Representation of a FSM
  64  */
  65 typedef struct fsm_instance_t {
  66         fsm *f;
  67         atomic_t state;
  68         char name[16];
  69         void *userdata;
  70         int userint;
  71 #if FSM_DEBUG_HISTORY
  72         int         history_index;
  73         int         history_size;
  74         fsm_history history[FSM_HISTORY_SIZE];
  75 #endif
  76 } fsm_instance;
  77
  78 /**
  79  * Description of a state-event combination
  80  */
  81 typedef struct {
  82         int cond_state;
  83         int cond_event;
  84         fsm_function_t function;
  85 } fsm_node;
  86
  87 /**
  88  * Description of a FSM Timer.
  89  */
  90 typedef struct {
  91         fsm_instance *fi;
  92         struct timer_list tl;
  93         int expire_event;
  94         void *event_arg;
  95 } fsm_timer;
  96
  97 /**
  98  * Creates an FSM
  99  *
 100  * @param name        Name of this instance for logging purposes.
 101  * @param state_names An array of names for all states for logging purposes.
 102  * @param event_names An array of names for all events for logging purposes.
 103  * @param nr_states   Number of states for this instance.
 104  * @param nr_events   Number of events for this instance.
 105  * @param tmpl        An array of fsm_nodes, describing this FSM.
 106  * @param tmpl_len    Length of the describing array.
 107  * @param order       Parameter for allocation of the FSM data structs.
 108  */
 109 extern fsm_instance *
 110 init_fsm(char *name, const char **state_names,
 111          const char **event_names,
 112          int nr_states, int nr_events, const fsm_node *tmpl,
 113          int tmpl_len, int order);
 114
 115 /**
 116  * Releases an FSM
 117  *
 118  * @param fi Pointer to an FSM, previously created with init_fsm.
 119  */
 120 extern void kfree_fsm(fsm_instance *fi);
 121
 122 #if FSM_DEBUG_HISTORY
 123 extern void
 124 fsm_print_history(fsm_instance *fi);
 125
 126 extern void
 127 fsm_record_history(fsm_instance *fi, int state, int event);
 128 #endif
 129
 130 /**
 131  * Emits an event to a FSM.
 132  * If an action function is defined for the current state/event combination,
 133  * this function is called.
 134  *
 135  * @param fi    Pointer to FSM which should receive the event.
 136  * @param event The event do be delivered.
 137  * @param arg   A generic argument, handed to the action function.
 138  *
 139  * @return      0  on success,
 140  *              1  if current state or event is out of range
 141  *              !0 if state and event in range, but no action defined.
 142  */
 143 extern __inline__ int
 144 fsm_event(fsm_instance *fi, int event, void *arg)
 145 {
 146         fsm_function_t r;
 147         int state = atomic_read(&fi->state);
 148
 149         if ((state >= fi->f->nr_states) ||
 150             (event >= fi->f->nr_events)       ) {
 151                 printk(KERN_ERR "fsm(%s): Invalid state st(%ld/%ld) ev(%d/%ld)\n",
 152                         fi->name, (long)state,(long)fi->f->nr_states, event,
 153                         (long)fi->f->nr_events);
 154 #if FSM_DEBUG_HISTORY
 155                 fsm_print_history(fi);
 156 #endif
 157                 return 1;
 158         }
 159         r = fi->f->jumpmatrix[fi->f->nr_states * event + state];
 160         if (r) {
 161 #if FSM_DEBUG
 162                 printk(KERN_DEBUG "fsm(%s): state %s event %s\n",
 163                        fi->name, fi->f->state_names[state],
 164                        fi->f->event_names[event]);
 165 #endif
 166 #if FSM_DEBUG_HISTORY
 167                 fsm_record_history(fi, state, event);
 168 #endif
 169                 r(fi, event, arg);
 170                 return 0;
 171         } else {
 172 #if FSM_DEBUG || FSM_DEBUG_HISTORY
 173                 printk(KERN_DEBUG "fsm(%s): no function for event %s in state %s\n",
 174                        fi->name, fi->f->event_names[event],
 175                        fi->f->state_names[state]);
 176 #endif
 177 #if FSM_DEBUG_HISTORY
 178                 fsm_print_history(fi);
 179 #endif
 180                 return !0;
 181         }
 182 }
 183
 184 /**
 185  * Modifies the state of an FSM.
 186  * This does <em>not</em> trigger an event or calls an action function.
 187  *
 188  * @param fi    Pointer to FSM
 189  * @param state The new state for this FSM.
 190  */
 191 extern __inline__ void
 192 fsm_newstate(fsm_instance *fi, int newstate)
 193 {
 194         atomic_set(&fi->state,newstate);
 195 #if FSM_DEBUG_HISTORY
 196         fsm_record_history(fi, newstate, -1);
 197 #endif
 198 #if FSM_DEBUG
 199         printk(KERN_DEBUG "fsm(%s): New state %s\n", fi->name,
 200                 fi->f->state_names[newstate]);
 201 #endif
 202 }
 203
 204 /**
 205  * Retrieves the state of an FSM
 206  *
 207  * @param fi Pointer to FSM
 208  *
 209  * @return The current state of the FSM.
 210  */
 211 extern __inline__ int
 212 fsm_getstate(fsm_instance *fi)
 213 {
 214         return atomic_read(&fi->state);
 215 }
 216
 217 /**
 218  * Retrieves the name of the state of an FSM
 219  *
 220  * @param fi Pointer to FSM
 221  *
 222  * @return The current state of the FSM in a human readable form.
 223  */
 224 extern const char *fsm_getstate_str(fsm_instance *fi);
 225
 226 /**
 227  * Initializes a timer for an FSM.
 228  * This prepares an fsm_timer for usage with fsm_addtimer.
 229  *
 230  * @param fi    Pointer to FSM
 231  * @param timer The timer to be initialized.
 232  */
 233 extern void fsm_settimer(fsm_instance *fi, fsm_timer *);
 234
 235 /**
 236  * Clears a pending timer of an FSM instance.
 237  *
 238  * @param timer The timer to clear.
 239  */
 240 extern void fsm_deltimer(fsm_timer *timer);
 241
 242 /**
 243  * Adds and starts a timer to an FSM instance.
 244  *
 245  * @param timer    The timer to be added. The field fi of that timer
 246  *                 must have been set to point to the instance.
 247  * @param millisec Duration, after which the timer should expire.
 248  * @param event    Event, to trigger if timer expires.
 249  * @param arg      Generic argument, provided to expiry function.
 250  *
 251  * @return         0 on success, -1 if timer is already active.
 252  */
 253 extern int fsm_addtimer(fsm_timer *timer, int millisec, int event, void *arg);
 254
 255 /**
 256  * Modifies a timer of an FSM.
 257  *
 258  * @param timer    The timer to modify.
 259  * @param millisec Duration, after which the timer should expire.
 260  * @param event    Event, to trigger if timer expires.
 261  * @param arg      Generic argument, provided to expiry function.
 262  */
 263 extern void fsm_modtimer(fsm_timer *timer, int millisec, int event, void *arg);
 264
 265 #endif /* _FSM_H_ */