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-rw-r--r--include/asm-arm/spinlock.h224
1 files changed, 0 insertions, 224 deletions
diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h
deleted file mode 100644
index 2b41ebbfa7ff..000000000000
--- a/include/asm-arm/spinlock.h
+++ /dev/null
@@ -1,224 +0,0 @@
1#ifndef __ASM_SPINLOCK_H
2#define __ASM_SPINLOCK_H
3
4#if __LINUX_ARM_ARCH__ < 6
5#error SMP not supported on pre-ARMv6 CPUs
6#endif
7
8/*
9 * ARMv6 Spin-locking.
10 *
11 * We exclusively read the old value. If it is zero, we may have
12 * won the lock, so we try exclusively storing it. A memory barrier
13 * is required after we get a lock, and before we release it, because
14 * V6 CPUs are assumed to have weakly ordered memory.
15 *
16 * Unlocked value: 0
17 * Locked value: 1
18 */
19
20#define __raw_spin_is_locked(x) ((x)->lock != 0)
21#define __raw_spin_unlock_wait(lock) \
22 do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)
23
24#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
25
26static inline void __raw_spin_lock(raw_spinlock_t *lock)
27{
28 unsigned long tmp;
29
30 __asm__ __volatile__(
31"1: ldrex %0, [%1]\n"
32" teq %0, #0\n"
33#ifdef CONFIG_CPU_32v6K
34" wfene\n"
35#endif
36" strexeq %0, %2, [%1]\n"
37" teqeq %0, #0\n"
38" bne 1b"
39 : "=&r" (tmp)
40 : "r" (&lock->lock), "r" (1)
41 : "cc");
42
43 smp_mb();
44}
45
46static inline int __raw_spin_trylock(raw_spinlock_t *lock)
47{
48 unsigned long tmp;
49
50 __asm__ __volatile__(
51" ldrex %0, [%1]\n"
52" teq %0, #0\n"
53" strexeq %0, %2, [%1]"
54 : "=&r" (tmp)
55 : "r" (&lock->lock), "r" (1)
56 : "cc");
57
58 if (tmp == 0) {
59 smp_mb();
60 return 1;
61 } else {
62 return 0;
63 }
64}
65
66static inline void __raw_spin_unlock(raw_spinlock_t *lock)
67{
68 smp_mb();
69
70 __asm__ __volatile__(
71" str %1, [%0]\n"
72#ifdef CONFIG_CPU_32v6K
73" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */
74" sev"
75#endif
76 :
77 : "r" (&lock->lock), "r" (0)
78 : "cc");
79}
80
81/*
82 * RWLOCKS
83 *
84 *
85 * Write locks are easy - we just set bit 31. When unlocking, we can
86 * just write zero since the lock is exclusively held.
87 */
88
89static inline void __raw_write_lock(raw_rwlock_t *rw)
90{
91 unsigned long tmp;
92
93 __asm__ __volatile__(
94"1: ldrex %0, [%1]\n"
95" teq %0, #0\n"
96#ifdef CONFIG_CPU_32v6K
97" wfene\n"
98#endif
99" strexeq %0, %2, [%1]\n"
100" teq %0, #0\n"
101" bne 1b"
102 : "=&r" (tmp)
103 : "r" (&rw->lock), "r" (0x80000000)
104 : "cc");
105
106 smp_mb();
107}
108
109static inline int __raw_write_trylock(raw_rwlock_t *rw)
110{
111 unsigned long tmp;
112
113 __asm__ __volatile__(
114"1: ldrex %0, [%1]\n"
115" teq %0, #0\n"
116" strexeq %0, %2, [%1]"
117 : "=&r" (tmp)
118 : "r" (&rw->lock), "r" (0x80000000)
119 : "cc");
120
121 if (tmp == 0) {
122 smp_mb();
123 return 1;
124 } else {
125 return 0;
126 }
127}
128
129static inline void __raw_write_unlock(raw_rwlock_t *rw)
130{
131 smp_mb();
132
133 __asm__ __volatile__(
134 "str %1, [%0]\n"
135#ifdef CONFIG_CPU_32v6K
136" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */
137" sev\n"
138#endif
139 :
140 : "r" (&rw->lock), "r" (0)
141 : "cc");
142}
143
144/* write_can_lock - would write_trylock() succeed? */
145#define __raw_write_can_lock(x) ((x)->lock == 0)
146
147/*
148 * Read locks are a bit more hairy:
149 * - Exclusively load the lock value.
150 * - Increment it.
151 * - Store new lock value if positive, and we still own this location.
152 * If the value is negative, we've already failed.
153 * - If we failed to store the value, we want a negative result.
154 * - If we failed, try again.
155 * Unlocking is similarly hairy. We may have multiple read locks
156 * currently active. However, we know we won't have any write
157 * locks.
158 */
159static inline void __raw_read_lock(raw_rwlock_t *rw)
160{
161 unsigned long tmp, tmp2;
162
163 __asm__ __volatile__(
164"1: ldrex %0, [%2]\n"
165" adds %0, %0, #1\n"
166" strexpl %1, %0, [%2]\n"
167#ifdef CONFIG_CPU_32v6K
168" wfemi\n"
169#endif
170" rsbpls %0, %1, #0\n"
171" bmi 1b"
172 : "=&r" (tmp), "=&r" (tmp2)
173 : "r" (&rw->lock)
174 : "cc");
175
176 smp_mb();
177}
178
179static inline void __raw_read_unlock(raw_rwlock_t *rw)
180{
181 unsigned long tmp, tmp2;
182
183 smp_mb();
184
185 __asm__ __volatile__(
186"1: ldrex %0, [%2]\n"
187" sub %0, %0, #1\n"
188" strex %1, %0, [%2]\n"
189" teq %1, #0\n"
190" bne 1b"
191#ifdef CONFIG_CPU_32v6K
192"\n cmp %0, #0\n"
193" mcreq p15, 0, %0, c7, c10, 4\n"
194" seveq"
195#endif
196 : "=&r" (tmp), "=&r" (tmp2)
197 : "r" (&rw->lock)
198 : "cc");
199}
200
201static inline int __raw_read_trylock(raw_rwlock_t *rw)
202{
203 unsigned long tmp, tmp2 = 1;
204
205 __asm__ __volatile__(
206"1: ldrex %0, [%2]\n"
207" adds %0, %0, #1\n"
208" strexpl %1, %0, [%2]\n"
209 : "=&r" (tmp), "+r" (tmp2)
210 : "r" (&rw->lock)
211 : "cc");
212
213 smp_mb();
214 return tmp2 == 0;
215}
216
217/* read_can_lock - would read_trylock() succeed? */
218#define __raw_read_can_lock(x) ((x)->lock < 0x80000000)
219
220#define _raw_spin_relax(lock) cpu_relax()
221#define _raw_read_relax(lock) cpu_relax()
222#define _raw_write_relax(lock) cpu_relax()
223
224#endif /* __ASM_SPINLOCK_H */
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