1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3 * Copyright (c) 2014, STMicroelectronics International N.V.
4 * Copyright (c) 2016, Linaro Limited
5 */
6
7 #ifndef __KERNEL_SPINLOCK_H
8 #define __KERNEL_SPINLOCK_H
9
10 #define SPINLOCK_LOCK 1
11 #define SPINLOCK_UNLOCK 0
12
13 #ifndef __ASSEMBLER__
14 #include <assert.h>
15 #include <compiler.h>
16 #include <kernel/thread.h>
17 #include <stdbool.h>
18
19 #ifdef CFG_TEE_CORE_DEBUG
20 void spinlock_count_incr(void);
21 void spinlock_count_decr(void);
22 bool have_spinlock(void);
assert_have_no_spinlock(void)23 static inline void __nostackcheck assert_have_no_spinlock(void)
24 {
25 assert(!have_spinlock());
26 }
27 #else
spinlock_count_incr(void)28 static inline void spinlock_count_incr(void) { }
spinlock_count_decr(void)29 static inline void spinlock_count_decr(void) { }
assert_have_no_spinlock(void)30 static inline void __nostackcheck assert_have_no_spinlock(void) { }
31 #endif
32
33 void __cpu_spin_lock(unsigned int *lock);
34 void __cpu_spin_unlock(unsigned int *lock);
35 /* returns 0 on locking success, non zero on failure */
36 unsigned int __cpu_spin_trylock(unsigned int *lock);
37
cpu_spin_lock_no_dldetect(unsigned int * lock)38 static inline void cpu_spin_lock_no_dldetect(unsigned int *lock)
39 {
40 assert(thread_foreign_intr_disabled());
41 __cpu_spin_lock(lock);
42 spinlock_count_incr();
43 }
44
thread_spin_trylock(unsigned int * lock)45 static inline bool thread_spin_trylock(unsigned int *lock)
46 {
47 assert(thread_get_id_may_fail() != THREAD_ID_INVALID);
48 return !__cpu_spin_trylock(lock);
49 }
50
51 /*
52 * To be used with lot of care: it is not recommended to spin in a thread
53 * context without masking foreign interrupts
54 */
thread_spin_lock(unsigned int * lock)55 static inline void thread_spin_lock(unsigned int *lock)
56 {
57 assert(thread_get_id_may_fail() != THREAD_ID_INVALID);
58 __cpu_spin_lock(lock);
59 }
60
thread_spin_unlock(unsigned int * lock)61 static inline void thread_spin_unlock(unsigned int *lock)
62 {
63 assert(thread_get_id_may_fail() != THREAD_ID_INVALID);
64 __cpu_spin_unlock(lock);
65 }
66
67 #ifdef CFG_TEE_CORE_DEBUG
68 #define cpu_spin_lock(lock) \
69 cpu_spin_lock_dldetect(__func__, __LINE__, lock)
70
cpu_spin_lock_dldetect(const char * func,const int line,unsigned int * lock)71 static inline void cpu_spin_lock_dldetect(const char *func, const int line,
72 unsigned int *lock)
73 {
74 unsigned int retries = 0;
75 unsigned int reminder = 0;
76
77 assert(thread_foreign_intr_disabled());
78
79 while (__cpu_spin_trylock(lock)) {
80 retries++;
81 if (!retries) {
82 /* wrapped, time to report */
83 trace_printf(func, line, TRACE_ERROR, true,
84 "possible spinlock deadlock reminder %u",
85 reminder);
86 if (reminder < UINT_MAX)
87 reminder++;
88 }
89 }
90
91 spinlock_count_incr();
92 }
93 #else
cpu_spin_lock(unsigned int * lock)94 static inline void cpu_spin_lock(unsigned int *lock)
95 {
96 cpu_spin_lock_no_dldetect(lock);
97 }
98 #endif
99
cpu_spin_trylock(unsigned int * lock)100 static inline bool cpu_spin_trylock(unsigned int *lock)
101 {
102 unsigned int rc;
103
104 assert(thread_foreign_intr_disabled());
105 rc = __cpu_spin_trylock(lock);
106 if (!rc)
107 spinlock_count_incr();
108 return !rc;
109 }
110
cpu_spin_unlock(unsigned int * lock)111 static inline void cpu_spin_unlock(unsigned int *lock)
112 {
113 assert(thread_foreign_intr_disabled());
114 __cpu_spin_unlock(lock);
115 spinlock_count_decr();
116 }
117
118 static inline uint32_t __must_check
cpu_spin_lock_xsave_no_dldetect(unsigned int * lock)119 cpu_spin_lock_xsave_no_dldetect(unsigned int *lock)
120 {
121 uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_ALL);
122
123 cpu_spin_lock(lock);
124 return exceptions;
125 }
126
127 #ifdef CFG_TEE_CORE_DEBUG
128 #define cpu_spin_lock_xsave(lock) \
129 cpu_spin_lock_xsave_dldetect(__func__, __LINE__, lock)
130
131 static inline uint32_t __must_check
cpu_spin_lock_xsave_dldetect(const char * func,const int line,unsigned int * lock)132 cpu_spin_lock_xsave_dldetect(const char *func, const int line,
133 unsigned int *lock)
134 {
135 uint32_t exceptions = thread_mask_exceptions(THREAD_EXCP_ALL);
136
137 cpu_spin_lock_dldetect(func, line, lock);
138 return exceptions;
139 }
140 #else
cpu_spin_lock_xsave(unsigned int * lock)141 static inline uint32_t __must_check cpu_spin_lock_xsave(unsigned int *lock)
142 {
143 return cpu_spin_lock_xsave_no_dldetect(lock);
144 }
145 #endif
146
cpu_spin_unlock_xrestore(unsigned int * lock,uint32_t exceptions)147 static inline void cpu_spin_unlock_xrestore(unsigned int *lock,
148 uint32_t exceptions)
149 {
150 cpu_spin_unlock(lock);
151 thread_unmask_exceptions(exceptions);
152 }
153 #endif /* __ASSEMBLER__ */
154
155 #endif /* __KERNEL_SPINLOCK_H */
156