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(size: sizeof(fsm_instance), flags: 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 | strscpy(p: this->name, q: name, size: sizeof(this->name)); |
32 | init_waitqueue_head(&this->wait_q); |
33 | |
34 | f = kzalloc(size: sizeof(fsm), flags: order); |
35 | if (f == NULL) { |
36 | printk(KERN_WARNING |
37 | "fsm(%s): init_fsm: Couldn't alloc fsm\n" , name); |
38 | kfree_fsm(fi: 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(n: nr_states*nr_events, size: sizeof(fsm_function_t), flags: order); |
48 | if (m == NULL) { |
49 | printk(KERN_WARNING |
50 | "fsm(%s): init_fsm: Couldn't alloc jumptable\n" , name); |
51 | kfree_fsm(fi: 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(fi: 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(objp: this->f->jumpmatrix); |
78 | kfree(objp: this->f); |
79 | } |
80 | kfree(objp: 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(v: &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(fi: this->fi, event: this->expire_event, arg: 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(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(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(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(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 |
211 | |