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 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 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 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 92 static inline void jump_label_inc(struct jump_label_key *key) 93 { 94 atomic_inc(&key->enabled); 95 } 96 97 static inline void jump_label_dec(struct jump_label_key *key) 98 { 99 atomic_dec(&key->enabled); 100 } 101 102 static inline void jump_label_dec_deferred(struct jump_label_key_deferred *key) 103 { 104 jump_label_dec(&key->key); 105 } 106 107 static inline int jump_label_text_reserved(void *start, void *end) 108 { 109 return 0; 110 } 111 112 static inline void jump_label_lock(void) {} 113 static inline void jump_label_unlock(void) {} 114 115 static inline bool jump_label_enabled(struct jump_label_key *key) 116 { 117 return !!atomic_read(&key->enabled); 118 } 119 120 static inline int jump_label_apply_nops(struct module *mod) 121 { 122 return 0; 123 } 124 125 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