drivers/s390/net/fsm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * A generic FSM based on fsm used in isdn4linux
   4  *
   5  */
   6
   7 #include "fsm.h"
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/timer.h>
  11
  12 MODULE_AUTHOR("(C) 2000 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
  13 MODULE_DESCRIPTION("Finite state machine helper functions");
  14 MODULE_LICENSE("GPL");
  15
  16 fsm_instance *
  17 init_fsm(char *name, const char **state_names, const char **event_names, int nr_states,
  18                 int nr_events, const fsm_node *tmpl, int tmpl_len, gfp_t order)
  19 {
  20         int i;
  21         fsm_instance *this;
  22         fsm_function_t *m;
  23         fsm *f;
  24
  25         this = kzalloc(sizeof(fsm_instance), order);
  26         if (this == NULL) {
  27                 printk(KERN_WARNING
  28                         "fsm(%s): init_fsm: Couldn't alloc instance\n", name);
  29                 return NULL;
  30         }
  31         strlcpy(this->name, name, sizeof(this->name));
  32         init_waitqueue_head(&this->wait_q);
  33
  34         f = kzalloc(sizeof(fsm), order);
  35         if (f == NULL) {
  36                 printk(KERN_WARNING
  37                         "fsm(%s): init_fsm: Couldn't alloc fsm\n", name);
  38                 kfree_fsm(this);
  39                 return NULL;
  40         }
  41         f->nr_events = nr_events;
  42         f->nr_states = nr_states;
  43         f->event_names = event_names;
  44         f->state_names = state_names;
  45         this->f = f;
  46
  47         m = kcalloc(nr_states*nr_events, sizeof(fsm_function_t), order);
  48         if (m == NULL) {
  49                 printk(KERN_WARNING
  50                         "fsm(%s): init_fsm: Couldn't alloc jumptable\n", name);
  51                 kfree_fsm(this);
  52                 return NULL;
  53         }
  54         f->jumpmatrix = m;
  55
  56         for (i = 0; i < tmpl_len; i++) {
  57                 if ((tmpl[i].cond_state >= nr_states) ||
  58                     (tmpl[i].cond_event >= nr_events)   ) {
  59                         printk(KERN_ERR
  60                                 "fsm(%s): init_fsm: Bad template l=%d st(%ld/%ld) ev(%ld/%ld)\n",
  61                                 name, i, (long)tmpl[i].cond_state, (long)f->nr_states,
  62                                 (long)tmpl[i].cond_event, (long)f->nr_events);
  63                         kfree_fsm(this);
  64                         return NULL;
  65                 } else
  66                         m[nr_states * tmpl[i].cond_event + tmpl[i].cond_state] =
  67                                 tmpl[i].function;
  68         }
  69         return this;
  70 }
  71
  72 void
  73 kfree_fsm(fsm_instance *this)
  74 {
  75         if (this) {
  76                 if (this->f) {
  77                         kfree(this->f->jumpmatrix);
  78                         kfree(this->f);
  79                 }
  80                 kfree(this);
  81         } else
  82                 printk(KERN_WARNING
  83                         "fsm: kfree_fsm called with NULL argument\n");
  84 }
  85
  86 #if FSM_DEBUG_HISTORY
  87 void
  88 fsm_print_history(fsm_instance *fi)
  89 {
  90         int idx = 0;
  91         int i;
  92
  93         if (fi->history_size >= FSM_HISTORY_SIZE)
  94                 idx = fi->history_index;
  95
  96         printk(KERN_DEBUG "fsm(%s): History:\n", fi->name);
  97         for (i = 0; i < fi->history_size; i++) {
  98                 int e = fi->history[idx].event;
  99                 int s = fi->history[idx++].state;
 100                 idx %= FSM_HISTORY_SIZE;
 101                 if (e == -1)
 102                         printk(KERN_DEBUG "  S=%s\n",
 103                                fi->f->state_names[s]);
 104                 else
 105                         printk(KERN_DEBUG "  S=%s E=%s\n",
 106                                fi->f->state_names[s],
 107                                fi->f->event_names[e]);
 108         }
 109         fi->history_size = fi->history_index = 0;
 110 }
 111
 112 void
 113 fsm_record_history(fsm_instance *fi, int state, int event)
 114 {
 115         fi->history[fi->history_index].state = state;
 116         fi->history[fi->history_index++].event = event;
 117         fi->history_index %= FSM_HISTORY_SIZE;
 118         if (fi->history_size < FSM_HISTORY_SIZE)
 119                 fi->history_size++;
 120 }
 121 #endif
 122
 123 const char *
 124 fsm_getstate_str(fsm_instance *fi)
 125 {
 126         int st = atomic_read(&fi->state);
 127         if (st >= fi->f->nr_states)
 128                 return "Invalid";
 129         return fi->f->state_names[st];
 130 }
 131
 132 static void
 133 fsm_expire_timer(struct timer_list *t)
 134 {
 135         fsm_timer *this = from_timer(this, t, tl);
 136 #if FSM_TIMER_DEBUG
 137         printk(KERN_DEBUG "fsm(%s): Timer %p expired\n",
 138                this->fi->name, this);
 139 #endif
 140         fsm_event(this->fi, this->expire_event, this->event_arg);
 141 }
 142
 143 void
 144 fsm_settimer(fsm_instance *fi, fsm_timer *this)
 145 {
 146         this->fi = fi;
 147 #if FSM_TIMER_DEBUG
 148         printk(KERN_DEBUG "fsm(%s): Create timer %p\n", fi->name,
 149                this);
 150 #endif
 151         timer_setup(&this->tl, fsm_expire_timer, 0);
 152 }
 153
 154 void
 155 fsm_deltimer(fsm_timer *this)
 156 {
 157 #if FSM_TIMER_DEBUG
 158         printk(KERN_DEBUG "fsm(%s): Delete timer %p\n", this->fi->name,
 159                 this);
 160 #endif
 161         del_timer(&this->tl);
 162 }
 163
 164 int
 165 fsm_addtimer(fsm_timer *this, int millisec, int event, void *arg)
 166 {
 167
 168 #if FSM_TIMER_DEBUG
 169         printk(KERN_DEBUG "fsm(%s): Add timer %p %dms\n",
 170                this->fi->name, this, millisec);
 171 #endif
 172
 173         timer_setup(&this->tl, fsm_expire_timer, 0);
 174         this->expire_event = event;
 175         this->event_arg = arg;
 176         this->tl.expires = jiffies + (millisec * HZ) / 1000;
 177         add_timer(&this->tl);
 178         return 0;
 179 }
 180
 181 /* FIXME: this function is never used, why */
 182 void
 183 fsm_modtimer(fsm_timer *this, int millisec, int event, void *arg)
 184 {
 185
 186 #if FSM_TIMER_DEBUG
 187         printk(KERN_DEBUG "fsm(%s): Restart timer %p %dms\n",
 188                 this->fi->name, this, millisec);
 189 #endif
 190
 191         del_timer(&this->tl);
 192         timer_setup(&this->tl, fsm_expire_timer, 0);
 193         this->expire_event = event;
 194         this->event_arg = arg;
 195         this->tl.expires = jiffies + (millisec * HZ) / 1000;
 196         add_timer(&this->tl);
 197 }
 198
 199 EXPORT_SYMBOL(init_fsm);
 200 EXPORT_SYMBOL(kfree_fsm);
 201 EXPORT_SYMBOL(fsm_settimer);
 202 EXPORT_SYMBOL(fsm_deltimer);
 203 EXPORT_SYMBOL(fsm_addtimer);
 204 EXPORT_SYMBOL(fsm_modtimer);
 205 EXPORT_SYMBOL(fsm_getstate_str);
 206
 207 #if FSM_DEBUG_HISTORY
 208 EXPORT_SYMBOL(fsm_print_history);
 209 EXPORT_SYMBOL(fsm_record_history);
 210 #endif