1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_LOCAL_LOCK_H
3 # error "Do not include directly, include linux/local_lock.h"
4 #endif
5 
6 #include <linux/percpu-defs.h>
7 #include <linux/lockdep.h>
8 
9 #ifndef CONFIG_PREEMPT_RT
10 
11 typedef struct {
12 #ifdef CONFIG_DEBUG_LOCK_ALLOC
13 	struct lockdep_map	dep_map;
14 	struct task_struct	*owner;
15 #endif
16 } local_lock_t;
17 
18 #ifdef CONFIG_DEBUG_LOCK_ALLOC
19 # define LOCAL_LOCK_DEBUG_INIT(lockname)		\
20 	.dep_map = {					\
21 		.name = #lockname,			\
22 		.wait_type_inner = LD_WAIT_CONFIG,	\
23 		.lock_type = LD_LOCK_PERCPU,		\
24 	},						\
25 	.owner = NULL,
26 
27 static inline void local_lock_acquire(local_lock_t *l)
28 {
29 	lock_map_acquire(&l->dep_map);
30 	DEBUG_LOCKS_WARN_ON(l->owner);
31 	l->owner = current;
32 }
33 
34 static inline void local_lock_release(local_lock_t *l)
35 {
36 	DEBUG_LOCKS_WARN_ON(l->owner != current);
37 	l->owner = NULL;
38 	lock_map_release(&l->dep_map);
39 }
40 
41 static inline void local_lock_debug_init(local_lock_t *l)
42 {
43 	l->owner = NULL;
44 }
45 #else /* CONFIG_DEBUG_LOCK_ALLOC */
46 # define LOCAL_LOCK_DEBUG_INIT(lockname)
47 static inline void local_lock_acquire(local_lock_t *l) { }
48 static inline void local_lock_release(local_lock_t *l) { }
49 static inline void local_lock_debug_init(local_lock_t *l) { }
50 #endif /* !CONFIG_DEBUG_LOCK_ALLOC */
51 
52 #define INIT_LOCAL_LOCK(lockname)	{ LOCAL_LOCK_DEBUG_INIT(lockname) }
53 
54 #define __local_lock_init(lock)					\
55 do {								\
56 	static struct lock_class_key __key;			\
57 								\
58 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));\
59 	lockdep_init_map_type(&(lock)->dep_map, #lock, &__key,  \
60 			      0, LD_WAIT_CONFIG, LD_WAIT_INV,	\
61 			      LD_LOCK_PERCPU);			\
62 	local_lock_debug_init(lock);				\
63 } while (0)
64 
65 #define __local_lock(lock)					\
66 	do {							\
67 		preempt_disable();				\
68 		local_lock_acquire(this_cpu_ptr(lock));		\
69 	} while (0)
70 
71 #define __local_lock_irq(lock)					\
72 	do {							\
73 		local_irq_disable();				\
74 		local_lock_acquire(this_cpu_ptr(lock));		\
75 	} while (0)
76 
77 #define __local_lock_irqsave(lock, flags)			\
78 	do {							\
79 		local_irq_save(flags);				\
80 		local_lock_acquire(this_cpu_ptr(lock));		\
81 	} while (0)
82 
83 #define __local_unlock(lock)					\
84 	do {							\
85 		local_lock_release(this_cpu_ptr(lock));		\
86 		preempt_enable();				\
87 	} while (0)
88 
89 #define __local_unlock_irq(lock)				\
90 	do {							\
91 		local_lock_release(this_cpu_ptr(lock));		\
92 		local_irq_enable();				\
93 	} while (0)
94 
95 #define __local_unlock_irqrestore(lock, flags)			\
96 	do {							\
97 		local_lock_release(this_cpu_ptr(lock));		\
98 		local_irq_restore(flags);			\
99 	} while (0)
100 
101 #else /* !CONFIG_PREEMPT_RT */
102 
103 /*
104  * On PREEMPT_RT local_lock maps to a per CPU spinlock, which protects the
105  * critical section while staying preemptible.
106  */
107 typedef spinlock_t local_lock_t;
108 
109 #define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))
110 
111 #define __local_lock_init(l)					\
112 	do {							\
113 		local_spin_lock_init((l));			\
114 	} while (0)
115 
116 #define __local_lock(__lock)					\
117 	do {							\
118 		migrate_disable();				\
119 		spin_lock(this_cpu_ptr((__lock)));		\
120 	} while (0)
121 
122 #define __local_lock_irq(lock)			__local_lock(lock)
123 
124 #define __local_lock_irqsave(lock, flags)			\
125 	do {							\
126 		typecheck(unsigned long, flags);		\
127 		flags = 0;					\
128 		__local_lock(lock);				\
129 	} while (0)
130 
131 #define __local_unlock(__lock)					\
132 	do {							\
133 		spin_unlock(this_cpu_ptr((__lock)));		\
134 		migrate_enable();				\
135 	} while (0)
136 
137 #define __local_unlock_irq(lock)		__local_unlock(lock)
138 
139 #define __local_unlock_irqrestore(lock, flags)	__local_unlock(lock)
140 
141 #endif /* CONFIG_PREEMPT_RT */
142