drivers/s390/net/fsm.c

   1 /**
   2  * A generic FSM based on fsm used in isdn4linux
   3  *
   4  */
   5
   6 #include "fsm.h"
   7 #include <linux/module.h>
   8 #include <linux/slab.h>
   9 #include <linux/timer.h>
  10
  11 MODULE_AUTHOR("(C) 2000 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
  12 MODULE_DESCRIPTION("Finite state machine helper functions");
  13 MODULE_LICENSE("GPL");
  14
  15 fsm_instance *
  16 init_fsm(char *name, const char **state_names, const char **event_names, int nr_states,
  17                 int nr_events, const fsm_node *tmpl, int tmpl_len, gfp_t order)
  18 {
  19         int i;
  20         fsm_instance *this;
  21         fsm_function_t *m;
  22         fsm *f;
  23
  24         this = kzalloc(sizeof(fsm_instance), order);
  25         if (this == NULL) {
  26                 printk(KERN_WARNING
  27                         "fsm(%s): init_fsm: Couldn't alloc instance\n", name);
  28                 return NULL;
  29         }
  30         strlcpy(this->name, name, sizeof(this->name));
  31         init_waitqueue_head(&this->wait_q);
  32
  33         f = kzalloc(sizeof(fsm), order);
  34         if (f == NULL) {
  35                 printk(KERN_WARNING
  36                         "fsm(%s): init_fsm: Couldn't alloc fsm\n", name);
  37                 kfree_fsm(this);
  38                 return NULL;
  39         }
  40         f->nr_events = nr_events;
  41         f->nr_states = nr_states;
  42         f->event_names = event_names;
  43         f->state_names = state_names;
  44         this->f = f;
  45
  46         m = kcalloc(nr_states*nr_events, sizeof(fsm_function_t), order);
  47         if (m == NULL) {
  48                 printk(KERN_WARNING
  49                         "fsm(%s): init_fsm: Couldn't alloc jumptable\n", name);
  50                 kfree_fsm(this);
  51                 return NULL;
  52         }
  53         f->jumpmatrix = m;
  54
  55         for (i = 0; i < tmpl_len; i++) {
  56                 if ((tmpl[i].cond_state >= nr_states) ||
  57                     (tmpl[i].cond_event >= nr_events)   ) {
  58                         printk(KERN_ERR
  59                                 "fsm(%s): init_fsm: Bad template l=%d st(%ld/%ld) ev(%ld/%ld)\n",
  60                                 name, i, (long)tmpl[i].cond_state, (long)f->nr_states,
  61                                 (long)tmpl[i].cond_event, (long)f->nr_events);
  62                         kfree_fsm(this);
  63                         return NULL;
  64                 } else
  65                         m[nr_states * tmpl[i].cond_event + tmpl[i].cond_state] =
  66                                 tmpl[i].function;
  67         }
  68         return this;
  69 }
  70
  71 void
  72 kfree_fsm(fsm_instance *this)
  73 {
  74         if (this) {
  75                 if (this->f) {
  76                         kfree(this->f->jumpmatrix);
  77                         kfree(this->f);
  78                 }
  79                 kfree(this);
  80         } else
  81                 printk(KERN_WARNING
  82                         "fsm: kfree_fsm called with NULL argument\n");
  83 }
  84
  85 #if FSM_DEBUG_HISTORY
  86 void
  87 fsm_print_history(fsm_instance *fi)
  88 {
  89         int idx = 0;
  90         int i;
  91
  92         if (fi->history_size >= FSM_HISTORY_SIZE)
  93                 idx = fi->history_index;
  94
  95         printk(KERN_DEBUG "fsm(%s): History:\n", fi->name);
  96         for (i = 0; i < fi->history_size; i++) {
  97                 int e = fi->history[idx].event;
  98                 int s = fi->history[idx++].state;
  99                 idx %= FSM_HISTORY_SIZE;
 100                 if (e == -1)
 101                         printk(KERN_DEBUG "  S=%s\n",
 102                                fi->f->state_names[s]);
 103                 else
 104                         printk(KERN_DEBUG "  S=%s E=%s\n",
 105                                fi->f->state_names[s],
 106                                fi->f->event_names[e]);
 107         }
 108         fi->history_size = fi->history_index = 0;
 109 }
 110
 111 void
 112 fsm_record_history(fsm_instance *fi, int state, int event)
 113 {
 114         fi->history[fi->history_index].state = state;
 115         fi->history[fi->history_index++].event = event;
 116         fi->history_index %= FSM_HISTORY_SIZE;
 117         if (fi->history_size < FSM_HISTORY_SIZE)
 118                 fi->history_size++;
 119 }
 120 #endif
 121
 122 const char *
 123 fsm_getstate_str(fsm_instance *fi)
 124 {
 125         int st = atomic_read(&fi->state);
 126         if (st >= fi->f->nr_states)
 127                 return "Invalid";
 128         return fi->f->state_names[st];
 129 }
 130
 131 static void
 132 fsm_expire_timer(struct timer_list *t)
 133 {
 134         fsm_timer *this = from_timer(this, t, tl);
 135 #if FSM_TIMER_DEBUG
 136         printk(KERN_DEBUG "fsm(%s): Timer %p expired\n",
 137                this->fi->name, this);
 138 #endif
 139         fsm_event(this->fi, this->expire_event, this->event_arg);
 140 }
 141
 142 void
 143 fsm_settimer(fsm_instance *fi, fsm_timer *this)
 144 {
 145         this->fi = fi;
 146 #if FSM_TIMER_DEBUG
 147         printk(KERN_DEBUG "fsm(%s): Create timer %p\n", fi->name,
 148                this);
 149 #endif
 150         timer_setup(&this->tl, fsm_expire_timer, 0);
 151 }
 152
 153 void
 154 fsm_deltimer(fsm_timer *this)
 155 {
 156 #if FSM_TIMER_DEBUG
 157         printk(KERN_DEBUG "fsm(%s): Delete timer %p\n", this->fi->name,
 158                 this);
 159 #endif
 160         del_timer(&this->tl);
 161 }
 162
 163 int
 164 fsm_addtimer(fsm_timer *this, int millisec, int event, void *arg)
 165 {
 166
 167 #if FSM_TIMER_DEBUG
 168         printk(KERN_DEBUG "fsm(%s): Add timer %p %dms\n",
 169                this->fi->name, this, millisec);
 170 #endif
 171
 172         timer_setup(&this->tl, fsm_expire_timer, 0);
 173         this->expire_event = event;
 174         this->event_arg = arg;
 175         this->tl.expires = jiffies + (millisec * HZ) / 1000;
 176         add_timer(&this->tl);
 177         return 0;
 178 }
 179
 180 /* FIXME: this function is never used, why */
 181 void
 182 fsm_modtimer(fsm_timer *this, int millisec, int event, void *arg)
 183 {
 184
 185 #if FSM_TIMER_DEBUG
 186         printk(KERN_DEBUG "fsm(%s): Restart timer %p %dms\n",
 187                 this->fi->name, this, millisec);
 188 #endif
 189
 190         del_timer(&this->tl);
 191         timer_setup(&this->tl, fsm_expire_timer, 0);
 192         this->expire_event = event;
 193         this->event_arg = arg;
 194         this->tl.expires = jiffies + (millisec * HZ) / 1000;
 195         add_timer(&this->tl);
 196 }
 197
 198 EXPORT_SYMBOL(init_fsm);
 199 EXPORT_SYMBOL(kfree_fsm);
 200 EXPORT_SYMBOL(fsm_settimer);
 201 EXPORT_SYMBOL(fsm_deltimer);
 202 EXPORT_SYMBOL(fsm_addtimer);
 203 EXPORT_SYMBOL(fsm_modtimer);
 204 EXPORT_SYMBOL(fsm_getstate_str);
 205
 206 #if FSM_DEBUG_HISTORY
 207 EXPORT_SYMBOL(fsm_print_history);
 208 EXPORT_SYMBOL(fsm_record_history);
 209 #endif