xref: /openbmc/linux/drivers/s390/net/fsm.c (revision 87c2ce3b)
1 /**
2  * $Id: fsm.c,v 1.6 2003/10/15 11:37:29 mschwide Exp $
3  *
4  * A generic FSM based on fsm used in isdn4linux
5  *
6  */
7 
8 #include "fsm.h"
9 #include <linux/config.h>
10 #include <linux/module.h>
11 #include <linux/timer.h>
12 
13 MODULE_AUTHOR("(C) 2000 IBM Corp. by Fritz Elfert (felfert@millenux.com)");
14 MODULE_DESCRIPTION("Finite state machine helper functions");
15 MODULE_LICENSE("GPL");
16 
17 fsm_instance *
18 init_fsm(char *name, const char **state_names, const char **event_names, int nr_states,
19 		int nr_events, const fsm_node *tmpl, int tmpl_len, gfp_t order)
20 {
21 	int i;
22 	fsm_instance *this;
23 	fsm_function_t *m;
24 	fsm *f;
25 
26 	this = (fsm_instance *)kmalloc(sizeof(fsm_instance), order);
27 	if (this == NULL) {
28 		printk(KERN_WARNING
29 			"fsm(%s): init_fsm: Couldn't alloc instance\n", name);
30 		return NULL;
31 	}
32 	memset(this, 0, sizeof(fsm_instance));
33 	strlcpy(this->name, name, sizeof(this->name));
34 
35 	f = (fsm *)kmalloc(sizeof(fsm), order);
36 	if (f == NULL) {
37 		printk(KERN_WARNING
38 			"fsm(%s): init_fsm: Couldn't alloc fsm\n", name);
39 		kfree_fsm(this);
40 		return NULL;
41 	}
42 	memset(f, 0, sizeof(fsm));
43 	f->nr_events = nr_events;
44 	f->nr_states = nr_states;
45 	f->event_names = event_names;
46 	f->state_names = state_names;
47 	this->f = f;
48 
49 	m = (fsm_function_t *)kmalloc(
50 			sizeof(fsm_function_t) * nr_states * nr_events, order);
51 	if (m == NULL) {
52 		printk(KERN_WARNING
53 			"fsm(%s): init_fsm: Couldn't alloc jumptable\n", name);
54 		kfree_fsm(this);
55 		return NULL;
56 	}
57 	memset(m, 0, sizeof(fsm_function_t) * f->nr_states * f->nr_events);
58 	f->jumpmatrix = m;
59 
60 	for (i = 0; i < tmpl_len; i++) {
61 		if ((tmpl[i].cond_state >= nr_states) ||
62 		    (tmpl[i].cond_event >= nr_events)   ) {
63 			printk(KERN_ERR
64 				"fsm(%s): init_fsm: Bad template l=%d st(%ld/%ld) ev(%ld/%ld)\n",
65 				name, i, (long)tmpl[i].cond_state, (long)f->nr_states,
66 				(long)tmpl[i].cond_event, (long)f->nr_events);
67 			kfree_fsm(this);
68 			return NULL;
69 		} else
70 			m[nr_states * tmpl[i].cond_event + tmpl[i].cond_state] =
71 				tmpl[i].function;
72 	}
73 	return this;
74 }
75 
76 void
77 kfree_fsm(fsm_instance *this)
78 {
79 	if (this) {
80 		if (this->f) {
81 			kfree(this->f->jumpmatrix);
82 			kfree(this->f);
83 		}
84 		kfree(this);
85 	} else
86 		printk(KERN_WARNING
87 			"fsm: kfree_fsm called with NULL argument\n");
88 }
89 
90 #if FSM_DEBUG_HISTORY
91 void
92 fsm_print_history(fsm_instance *fi)
93 {
94 	int idx = 0;
95 	int i;
96 
97 	if (fi->history_size >= FSM_HISTORY_SIZE)
98 		idx = fi->history_index;
99 
100 	printk(KERN_DEBUG "fsm(%s): History:\n", fi->name);
101 	for (i = 0; i < fi->history_size; i++) {
102 		int e = fi->history[idx].event;
103 		int s = fi->history[idx++].state;
104 		idx %= FSM_HISTORY_SIZE;
105 		if (e == -1)
106 			printk(KERN_DEBUG "  S=%s\n",
107 			       fi->f->state_names[s]);
108 		else
109 			printk(KERN_DEBUG "  S=%s E=%s\n",
110 			       fi->f->state_names[s],
111 			       fi->f->event_names[e]);
112 	}
113 	fi->history_size = fi->history_index = 0;
114 }
115 
116 void
117 fsm_record_history(fsm_instance *fi, int state, int event)
118 {
119 	fi->history[fi->history_index].state = state;
120 	fi->history[fi->history_index++].event = event;
121 	fi->history_index %= FSM_HISTORY_SIZE;
122 	if (fi->history_size < FSM_HISTORY_SIZE)
123 		fi->history_size++;
124 }
125 #endif
126 
127 const char *
128 fsm_getstate_str(fsm_instance *fi)
129 {
130 	int st = atomic_read(&fi->state);
131 	if (st >= fi->f->nr_states)
132 		return "Invalid";
133 	return fi->f->state_names[st];
134 }
135 
136 static void
137 fsm_expire_timer(fsm_timer *this)
138 {
139 #if FSM_TIMER_DEBUG
140 	printk(KERN_DEBUG "fsm(%s): Timer %p expired\n",
141 	       this->fi->name, this);
142 #endif
143 	fsm_event(this->fi, this->expire_event, this->event_arg);
144 }
145 
146 void
147 fsm_settimer(fsm_instance *fi, fsm_timer *this)
148 {
149 	this->fi = fi;
150 	this->tl.function = (void *)fsm_expire_timer;
151 	this->tl.data = (long)this;
152 #if FSM_TIMER_DEBUG
153 	printk(KERN_DEBUG "fsm(%s): Create timer %p\n", fi->name,
154 	       this);
155 #endif
156 	init_timer(&this->tl);
157 }
158 
159 void
160 fsm_deltimer(fsm_timer *this)
161 {
162 #if FSM_TIMER_DEBUG
163 	printk(KERN_DEBUG "fsm(%s): Delete timer %p\n", this->fi->name,
164 		this);
165 #endif
166 	del_timer(&this->tl);
167 }
168 
169 int
170 fsm_addtimer(fsm_timer *this, int millisec, int event, void *arg)
171 {
172 
173 #if FSM_TIMER_DEBUG
174 	printk(KERN_DEBUG "fsm(%s): Add timer %p %dms\n",
175 	       this->fi->name, this, millisec);
176 #endif
177 
178 	init_timer(&this->tl);
179 	this->tl.function = (void *)fsm_expire_timer;
180 	this->tl.data = (long)this;
181 	this->expire_event = event;
182 	this->event_arg = arg;
183 	this->tl.expires = jiffies + (millisec * HZ) / 1000;
184 	add_timer(&this->tl);
185 	return 0;
186 }
187 
188 /* FIXME: this function is never used, why */
189 void
190 fsm_modtimer(fsm_timer *this, int millisec, int event, void *arg)
191 {
192 
193 #if FSM_TIMER_DEBUG
194 	printk(KERN_DEBUG "fsm(%s): Restart timer %p %dms\n",
195 		this->fi->name, this, millisec);
196 #endif
197 
198 	del_timer(&this->tl);
199 	init_timer(&this->tl);
200 	this->tl.function = (void *)fsm_expire_timer;
201 	this->tl.data = (long)this;
202 	this->expire_event = event;
203 	this->event_arg = arg;
204 	this->tl.expires = jiffies + (millisec * HZ) / 1000;
205 	add_timer(&this->tl);
206 }
207 
208 EXPORT_SYMBOL(init_fsm);
209 EXPORT_SYMBOL(kfree_fsm);
210 EXPORT_SYMBOL(fsm_settimer);
211 EXPORT_SYMBOL(fsm_deltimer);
212 EXPORT_SYMBOL(fsm_addtimer);
213 EXPORT_SYMBOL(fsm_modtimer);
214 EXPORT_SYMBOL(fsm_getstate_str);
215 
216 #if FSM_DEBUG_HISTORY
217 EXPORT_SYMBOL(fsm_print_history);
218 EXPORT_SYMBOL(fsm_record_history);
219 #endif
220