1 #ifndef _LINUX_JUMP_LABEL_H
2 #define _LINUX_JUMP_LABEL_H
3
4 #include <linux/types.h>
5 #include <linux/compiler.h>
6 #include <linux/workqueue.h>
7
8 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
9
10 struct jump_label_key {
11 atomic_t enabled;
12 struct jump_entry *entries;
13 #ifdef CONFIG_MODULES
14 struct jump_label_mod *next;
15 #endif
16 };
17
18 struct jump_label_key_deferred {
19 struct jump_label_key key;
20 unsigned long timeout;
21 struct delayed_work work;
22 };
23
24 # include <asm/jump_label.h>
25 # define HAVE_JUMP_LABEL
26 #endif /* CC_HAVE_ASM_GOTO && CONFIG_JUMP_LABEL */
27
28 enum jump_label_type {
29 JUMP_LABEL_DISABLE = 0,
30 JUMP_LABEL_ENABLE,
31 };
32
33 struct module;
34
35 #ifdef HAVE_JUMP_LABEL
36
37 #ifdef CONFIG_MODULES
38 #define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL, NULL}
39 #else
40 #define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL}
41 #endif
42
static_branch(struct jump_label_key * key)43 static __always_inline bool static_branch(struct jump_label_key *key)
44 {
45 return arch_static_branch(key);
46 }
47
48 extern struct jump_entry __start___jump_table[];
49 extern struct jump_entry __stop___jump_table[];
50
51 extern void jump_label_init(void);
52 extern void jump_label_lock(void);
53 extern void jump_label_unlock(void);
54 extern void arch_jump_label_transform(struct jump_entry *entry,
55 enum jump_label_type type);
56 extern void arch_jump_label_transform_static(struct jump_entry *entry,
57 enum jump_label_type type);
58 extern int jump_label_text_reserved(void *start, void *end);
59 extern void jump_label_inc(struct jump_label_key *key);
60 extern void jump_label_dec(struct jump_label_key *key);
61 extern void jump_label_dec_deferred(struct jump_label_key_deferred *key);
62 extern bool jump_label_enabled(struct jump_label_key *key);
63 extern void jump_label_apply_nops(struct module *mod);
64 extern void jump_label_rate_limit(struct jump_label_key_deferred *key,
65 unsigned long rl);
66
67 #else /* !HAVE_JUMP_LABEL */
68
69 #include <linux/atomic.h>
70
71 #define JUMP_LABEL_INIT {ATOMIC_INIT(0)}
72
73 struct jump_label_key {
74 atomic_t enabled;
75 };
76
jump_label_init(void)77 static __always_inline void jump_label_init(void)
78 {
79 }
80
81 struct jump_label_key_deferred {
82 struct jump_label_key key;
83 };
84
static_branch(struct jump_label_key * key)85 static __always_inline bool static_branch(struct jump_label_key *key)
86 {
87 if (unlikely(atomic_read(&key->enabled)))
88 return true;
89 return false;
90 }
91
jump_label_inc(struct jump_label_key * key)92 static inline void jump_label_inc(struct jump_label_key *key)
93 {
94 atomic_inc(&key->enabled);
95 }
96
jump_label_dec(struct jump_label_key * key)97 static inline void jump_label_dec(struct jump_label_key *key)
98 {
99 atomic_dec(&key->enabled);
100 }
101
jump_label_dec_deferred(struct jump_label_key_deferred * key)102 static inline void jump_label_dec_deferred(struct jump_label_key_deferred *key)
103 {
104 jump_label_dec(&key->key);
105 }
106
jump_label_text_reserved(void * start,void * end)107 static inline int jump_label_text_reserved(void *start, void *end)
108 {
109 return 0;
110 }
111
jump_label_lock(void)112 static inline void jump_label_lock(void) {}
jump_label_unlock(void)113 static inline void jump_label_unlock(void) {}
114
jump_label_enabled(struct jump_label_key * key)115 static inline bool jump_label_enabled(struct jump_label_key *key)
116 {
117 return !!atomic_read(&key->enabled);
118 }
119
jump_label_apply_nops(struct module * mod)120 static inline int jump_label_apply_nops(struct module *mod)
121 {
122 return 0;
123 }
124
jump_label_rate_limit(struct jump_label_key_deferred * key,unsigned long rl)125 static inline void jump_label_rate_limit(struct jump_label_key_deferred *key,
126 unsigned long rl)
127 {
128 }
129 #endif /* HAVE_JUMP_LABEL */
130
131 #define jump_label_key_enabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(1), })
132 #define jump_label_key_disabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(0), })
133
134 #endif /* _LINUX_JUMP_LABEL_H */
135