| Nicholas Flintham | 1e3d311 | 2013-04-10 10:48:38 +0100 | [diff] [blame^] | 1 | #ifndef __LINUX_BIT_SPINLOCK_H |
| 2 | #define __LINUX_BIT_SPINLOCK_H |
| 3 | |
| 4 | #include <linux/kernel.h> |
| 5 | #include <linux/preempt.h> |
| 6 | #include <linux/atomic.h> |
| 7 | #include <linux/bug.h> |
| 8 | |
| 9 | static inline void bit_spin_lock(int bitnum, unsigned long *addr) |
| 10 | { |
| 11 | preempt_disable(); |
| 12 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
| 13 | while (unlikely(test_and_set_bit_lock(bitnum, addr))) { |
| 14 | preempt_enable(); |
| 15 | do { |
| 16 | cpu_relax(); |
| 17 | } while (test_bit(bitnum, addr)); |
| 18 | preempt_disable(); |
| 19 | } |
| 20 | #endif |
| 21 | __acquire(bitlock); |
| 22 | } |
| 23 | |
| 24 | static inline int bit_spin_trylock(int bitnum, unsigned long *addr) |
| 25 | { |
| 26 | preempt_disable(); |
| 27 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
| 28 | if (unlikely(test_and_set_bit_lock(bitnum, addr))) { |
| 29 | preempt_enable(); |
| 30 | return 0; |
| 31 | } |
| 32 | #endif |
| 33 | __acquire(bitlock); |
| 34 | return 1; |
| 35 | } |
| 36 | |
| 37 | static inline void bit_spin_unlock(int bitnum, unsigned long *addr) |
| 38 | { |
| 39 | #ifdef CONFIG_DEBUG_SPINLOCK |
| 40 | BUG_ON(!test_bit(bitnum, addr)); |
| 41 | #endif |
| 42 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
| 43 | clear_bit_unlock(bitnum, addr); |
| 44 | #endif |
| 45 | preempt_enable(); |
| 46 | __release(bitlock); |
| 47 | } |
| 48 | |
| 49 | static inline void __bit_spin_unlock(int bitnum, unsigned long *addr) |
| 50 | { |
| 51 | #ifdef CONFIG_DEBUG_SPINLOCK |
| 52 | BUG_ON(!test_bit(bitnum, addr)); |
| 53 | #endif |
| 54 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
| 55 | __clear_bit_unlock(bitnum, addr); |
| 56 | #endif |
| 57 | preempt_enable(); |
| 58 | __release(bitlock); |
| 59 | } |
| 60 | |
| 61 | static inline int bit_spin_is_locked(int bitnum, unsigned long *addr) |
| 62 | { |
| 63 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
| 64 | return test_bit(bitnum, addr); |
| 65 | #elif defined CONFIG_PREEMPT_COUNT |
| 66 | return preempt_count(); |
| 67 | #else |
| 68 | return 1; |
| 69 | #endif |
| 70 | } |
| 71 | |
| 72 | #endif |
| 73 | |