| Nicholas Flintham | 1e3d311 | 2013-04-10 10:48:38 +0100 | [diff] [blame^] | 1 | #ifndef _ASM_MUTEX_H |
| 2 | #define _ASM_MUTEX_H |
| 3 | |
| 4 | #if __LINUX_ARM_ARCH__ < 6 |
| 5 | # include <asm-generic/mutex-xchg.h> |
| 6 | #else |
| 7 | |
| 8 | static inline void |
| 9 | __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) |
| 10 | { |
| 11 | int __ex_flag, __res; |
| 12 | |
| 13 | __asm__ ( |
| 14 | |
| 15 | "ldrex %0, [%2] \n\t" |
| 16 | "sub %0, %0, #1 \n\t" |
| 17 | "strex %1, %0, [%2] " |
| 18 | |
| 19 | : "=&r" (__res), "=&r" (__ex_flag) |
| 20 | : "r" (&(count)->counter) |
| 21 | : "cc","memory" ); |
| 22 | |
| 23 | __res |= __ex_flag; |
| 24 | if (unlikely(__res != 0)) |
| 25 | fail_fn(count); |
| 26 | else |
| 27 | smp_rmb(); |
| 28 | } |
| 29 | |
| 30 | static inline int |
| 31 | __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) |
| 32 | { |
| 33 | int __ex_flag, __res; |
| 34 | |
| 35 | __asm__ ( |
| 36 | |
| 37 | "ldrex %0, [%2] \n\t" |
| 38 | "sub %0, %0, #1 \n\t" |
| 39 | "strex %1, %0, [%2] " |
| 40 | |
| 41 | : "=&r" (__res), "=&r" (__ex_flag) |
| 42 | : "r" (&(count)->counter) |
| 43 | : "cc","memory" ); |
| 44 | |
| 45 | __res |= __ex_flag; |
| 46 | if (unlikely(__res != 0)) |
| 47 | __res = fail_fn(count); |
| 48 | else |
| 49 | smp_rmb(); |
| 50 | |
| 51 | return __res; |
| 52 | } |
| 53 | |
| 54 | static inline void |
| 55 | __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) |
| 56 | { |
| 57 | int __ex_flag, __res, __orig; |
| 58 | |
| 59 | smp_wmb(); |
| 60 | __asm__ ( |
| 61 | |
| 62 | "ldrex %0, [%3] \n\t" |
| 63 | "add %1, %0, #1 \n\t" |
| 64 | "strex %2, %1, [%3] " |
| 65 | |
| 66 | : "=&r" (__orig), "=&r" (__res), "=&r" (__ex_flag) |
| 67 | : "r" (&(count)->counter) |
| 68 | : "cc","memory" ); |
| 69 | |
| 70 | __orig |= __ex_flag; |
| 71 | if (unlikely(__orig != 0)) |
| 72 | fail_fn(count); |
| 73 | } |
| 74 | |
| 75 | #define __mutex_slowpath_needs_to_unlock() 1 |
| 76 | |
| 77 | static inline int |
| 78 | __mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) |
| 79 | { |
| 80 | int __ex_flag, __res, __orig; |
| 81 | |
| 82 | __asm__ ( |
| 83 | |
| 84 | "1: ldrex %0, [%3] \n\t" |
| 85 | "subs %1, %0, #1 \n\t" |
| 86 | "strexeq %2, %1, [%3] \n\t" |
| 87 | "movlt %0, #0 \n\t" |
| 88 | "cmpeq %2, #0 \n\t" |
| 89 | "bgt 1b " |
| 90 | |
| 91 | : "=&r" (__orig), "=&r" (__res), "=&r" (__ex_flag) |
| 92 | : "r" (&count->counter) |
| 93 | : "cc", "memory" ); |
| 94 | if (__orig) |
| 95 | smp_rmb(); |
| 96 | |
| 97 | return __orig; |
| 98 | } |
| 99 | |
| 100 | #endif |
| 101 | #endif |