1 #ifndef __LINUX_SPINLOCK_UP_H 1 #ifndef __LINUX_SPINLOCK_UP_H
2 #define __LINUX_SPINLOCK_UP_H 2 #define __LINUX_SPINLOCK_UP_H
3 3
4 #ifndef __LINUX_INSIDE_SPINLOCK_H !! 4 #ifndef __LINUX_SPINLOCK_H
5 # error "please don't include this file direct 5 # error "please don't include this file directly"
6 #endif 6 #endif
7 7
8 #include <asm/processor.h> /* for cpu_rel 8 #include <asm/processor.h> /* for cpu_relax() */
9 #include <asm/barrier.h> <<
10 9
11 /* 10 /*
12 * include/linux/spinlock_up.h - UP-debug vers 11 * include/linux/spinlock_up.h - UP-debug version of spinlocks.
13 * 12 *
14 * portions Copyright 2005, Red Hat, Inc., Ing 13 * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
15 * Released under the General Public License ( 14 * Released under the General Public License (GPL).
16 * 15 *
17 * In the debug case, 1 means unlocked, 0 mean 16 * In the debug case, 1 means unlocked, 0 means locked. (the values
18 * are inverted, to catch initialization bugs) 17 * are inverted, to catch initialization bugs)
19 * 18 *
20 * No atomicity anywhere, we are on UP. Howeve 19 * No atomicity anywhere, we are on UP. However, we still need
21 * the compiler barriers, because we do not wa 20 * the compiler barriers, because we do not want the compiler to
22 * move potentially faulting instructions (not 21 * move potentially faulting instructions (notably user accesses)
23 * into the locked sequence, resulting in non- 22 * into the locked sequence, resulting in non-atomic execution.
24 */ 23 */
25 24
26 #ifdef CONFIG_DEBUG_SPINLOCK 25 #ifdef CONFIG_DEBUG_SPINLOCK
27 #define arch_spin_is_locked(x) ((x)-> 26 #define arch_spin_is_locked(x) ((x)->slock == 0)
28 27
29 static inline void arch_spin_lock(arch_spinloc 28 static inline void arch_spin_lock(arch_spinlock_t *lock)
30 { 29 {
31 lock->slock = 0; 30 lock->slock = 0;
32 barrier(); 31 barrier();
33 } 32 }
34 33
>> 34 static inline void
>> 35 arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
>> 36 {
>> 37 local_irq_save(flags);
>> 38 lock->slock = 0;
>> 39 barrier();
>> 40 }
>> 41
35 static inline int arch_spin_trylock(arch_spinl 42 static inline int arch_spin_trylock(arch_spinlock_t *lock)
36 { 43 {
37 char oldval = lock->slock; 44 char oldval = lock->slock;
38 45
39 lock->slock = 0; 46 lock->slock = 0;
40 barrier(); 47 barrier();
41 48
42 return oldval > 0; 49 return oldval > 0;
43 } 50 }
44 51
45 static inline void arch_spin_unlock(arch_spinl 52 static inline void arch_spin_unlock(arch_spinlock_t *lock)
46 { 53 {
47 barrier(); 54 barrier();
48 lock->slock = 1; 55 lock->slock = 1;
49 } 56 }
50 57
51 /* 58 /*
52 * Read-write spinlocks. No debug version. 59 * Read-write spinlocks. No debug version.
53 */ 60 */
54 #define arch_read_lock(lock) do { b 61 #define arch_read_lock(lock) do { barrier(); (void)(lock); } while (0)
55 #define arch_write_lock(lock) do { b 62 #define arch_write_lock(lock) do { barrier(); (void)(lock); } while (0)
56 #define arch_read_trylock(lock) ({ barrier(); 63 #define arch_read_trylock(lock) ({ barrier(); (void)(lock); 1; })
57 #define arch_write_trylock(lock) ({ bar 64 #define arch_write_trylock(lock) ({ barrier(); (void)(lock); 1; })
58 #define arch_read_unlock(lock) do { b 65 #define arch_read_unlock(lock) do { barrier(); (void)(lock); } while (0)
59 #define arch_write_unlock(lock) do { barrier() 66 #define arch_write_unlock(lock) do { barrier(); (void)(lock); } while (0)
60 67
61 #else /* DEBUG_SPINLOCK */ 68 #else /* DEBUG_SPINLOCK */
62 #define arch_spin_is_locked(lock) ((void 69 #define arch_spin_is_locked(lock) ((void)(lock), 0)
63 /* for sched/core.c and kernel_lock.c: */ 70 /* for sched/core.c and kernel_lock.c: */
64 # define arch_spin_lock(lock) do { b 71 # define arch_spin_lock(lock) do { barrier(); (void)(lock); } while (0)
>> 72 # define arch_spin_lock_flags(lock, flags) do { barrier(); (void)(lock); } while (0)
65 # define arch_spin_unlock(lock) do { barrier() 73 # define arch_spin_unlock(lock) do { barrier(); (void)(lock); } while (0)
66 # define arch_spin_trylock(lock) ({ bar 74 # define arch_spin_trylock(lock) ({ barrier(); (void)(lock); 1; })
67 #endif /* DEBUG_SPINLOCK */ 75 #endif /* DEBUG_SPINLOCK */
68 76
69 #define arch_spin_is_contended(lock) (((voi 77 #define arch_spin_is_contended(lock) (((void)(lock), 0))
>> 78
>> 79 #define arch_read_can_lock(lock) (((void)(lock), 1))
>> 80 #define arch_write_can_lock(lock) (((void)(lock), 1))
>> 81
>> 82 #define arch_spin_unlock_wait(lock) \
>> 83 do { cpu_relax(); } while (arch_spin_is_locked(lock))
70 84
71 #endif /* __LINUX_SPINLOCK_UP_H */ 85 #endif /* __LINUX_SPINLOCK_UP_H */
72 86
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