jump_label: add arch_jump_label_transform_static() to optimise non-live code updates
[linux-2.6.git] / include / linux / jump_label.h
1 #ifndef _LINUX_JUMP_LABEL_H
2 #define _LINUX_JUMP_LABEL_H
3
4 #include <linux/types.h>
5 #include <linux/compiler.h>
6
7 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
8
9 struct jump_label_key {
10         atomic_t enabled;
11         struct jump_entry *entries;
12 #ifdef CONFIG_MODULES
13         struct jump_label_mod *next;
14 #endif
15 };
16
17 # include <asm/jump_label.h>
18 # define HAVE_JUMP_LABEL
19 #endif
20
21 enum jump_label_type {
22         JUMP_LABEL_DISABLE = 0,
23         JUMP_LABEL_ENABLE,
24 };
25
26 struct module;
27
28 #ifdef HAVE_JUMP_LABEL
29
30 #ifdef CONFIG_MODULES
31 #define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL, NULL}
32 #else
33 #define JUMP_LABEL_INIT {ATOMIC_INIT(0), NULL}
34 #endif
35
36 static __always_inline bool static_branch(struct jump_label_key *key)
37 {
38         return arch_static_branch(key);
39 }
40
41 extern struct jump_entry __start___jump_table[];
42 extern struct jump_entry __stop___jump_table[];
43
44 extern void jump_label_lock(void);
45 extern void jump_label_unlock(void);
46 extern void arch_jump_label_transform(struct jump_entry *entry,
47                                       enum jump_label_type type);
48 extern void arch_jump_label_transform_static(struct jump_entry *entry,
49                                              enum jump_label_type type);
50 extern int jump_label_text_reserved(void *start, void *end);
51 extern void jump_label_inc(struct jump_label_key *key);
52 extern void jump_label_dec(struct jump_label_key *key);
53 extern bool jump_label_enabled(struct jump_label_key *key);
54 extern void jump_label_apply_nops(struct module *mod);
55
56 #else
57
58 #include <linux/atomic.h>
59
60 #define JUMP_LABEL_INIT {ATOMIC_INIT(0)}
61
62 struct jump_label_key {
63         atomic_t enabled;
64 };
65
66 static __always_inline bool static_branch(struct jump_label_key *key)
67 {
68         if (unlikely(atomic_read(&key->enabled)))
69                 return true;
70         return false;
71 }
72
73 static inline void jump_label_inc(struct jump_label_key *key)
74 {
75         atomic_inc(&key->enabled);
76 }
77
78 static inline void jump_label_dec(struct jump_label_key *key)
79 {
80         atomic_dec(&key->enabled);
81 }
82
83 static inline int jump_label_text_reserved(void *start, void *end)
84 {
85         return 0;
86 }
87
88 static inline void jump_label_lock(void) {}
89 static inline void jump_label_unlock(void) {}
90
91 static inline bool jump_label_enabled(struct jump_label_key *key)
92 {
93         return !!atomic_read(&key->enabled);
94 }
95
96 static inline int jump_label_apply_nops(struct module *mod)
97 {
98         return 0;
99 }
100
101 #endif
102
103 #endif