| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _M68K_SEMAPHORE_HELPER_H |
| 2 | #define _M68K_SEMAPHORE_HELPER_H |
| 3 | |
| 4 | /* |
| 5 | * SMP- and interrupt-safe semaphores helper functions. |
| 6 | * |
| 7 | * (C) Copyright 1996 Linus Torvalds |
| 8 | * |
| 9 | * m68k version by Andreas Schwab |
| 10 | */ |
| 11 | |
| 12 | #include <linux/config.h> |
| 13 | #include <linux/errno.h> |
| 14 | |
| 15 | /* |
| 16 | * These two _must_ execute atomically wrt each other. |
| 17 | */ |
| 18 | static inline void wake_one_more(struct semaphore * sem) |
| 19 | { |
| 20 | atomic_inc(&sem->waking); |
| 21 | } |
| 22 | |
| 23 | #ifndef CONFIG_RMW_INSNS |
| 24 | extern spinlock_t semaphore_wake_lock; |
| 25 | #endif |
| 26 | |
| 27 | static inline int waking_non_zero(struct semaphore *sem) |
| 28 | { |
| 29 | int ret; |
| 30 | #ifndef CONFIG_RMW_INSNS |
| 31 | unsigned long flags; |
| 32 | |
| 33 | spin_lock_irqsave(&semaphore_wake_lock, flags); |
| 34 | ret = 0; |
| 35 | if (atomic_read(&sem->waking) > 0) { |
| 36 | atomic_dec(&sem->waking); |
| 37 | ret = 1; |
| 38 | } |
| 39 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| 40 | #else |
| 41 | int tmp1, tmp2; |
| 42 | |
| 43 | __asm__ __volatile__ |
| 44 | ("1: movel %1,%2\n" |
| 45 | " jle 2f\n" |
| 46 | " subql #1,%2\n" |
| 47 | " casl %1,%2,%3\n" |
| 48 | " jne 1b\n" |
| 49 | " moveq #1,%0\n" |
| 50 | "2:" |
| 51 | : "=d" (ret), "=d" (tmp1), "=d" (tmp2) |
| 52 | : "m" (sem->waking), "0" (0), "1" (sem->waking)); |
| 53 | #endif |
| 54 | |
| 55 | return ret; |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * waking_non_zero_interruptible: |
| 60 | * 1 got the lock |
| 61 | * 0 go to sleep |
| 62 | * -EINTR interrupted |
| 63 | */ |
| 64 | static inline int waking_non_zero_interruptible(struct semaphore *sem, |
| 65 | struct task_struct *tsk) |
| 66 | { |
| 67 | int ret; |
| 68 | #ifndef CONFIG_RMW_INSNS |
| 69 | unsigned long flags; |
| 70 | |
| 71 | spin_lock_irqsave(&semaphore_wake_lock, flags); |
| 72 | ret = 0; |
| 73 | if (atomic_read(&sem->waking) > 0) { |
| 74 | atomic_dec(&sem->waking); |
| 75 | ret = 1; |
| 76 | } else if (signal_pending(tsk)) { |
| 77 | atomic_inc(&sem->count); |
| 78 | ret = -EINTR; |
| 79 | } |
| 80 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| 81 | #else |
| 82 | int tmp1, tmp2; |
| 83 | |
| 84 | __asm__ __volatile__ |
| 85 | ("1: movel %1,%2\n" |
| 86 | " jle 2f\n" |
| 87 | " subql #1,%2\n" |
| 88 | " casl %1,%2,%3\n" |
| 89 | " jne 1b\n" |
| 90 | " moveq #1,%0\n" |
| 91 | " jra %a4\n" |
| 92 | "2:" |
| 93 | : "=d" (ret), "=d" (tmp1), "=d" (tmp2) |
| 94 | : "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking)); |
| 95 | if (signal_pending(tsk)) { |
| 96 | atomic_inc(&sem->count); |
| 97 | ret = -EINTR; |
| 98 | } |
| 99 | next: |
| 100 | #endif |
| 101 | |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * waking_non_zero_trylock: |
| 107 | * 1 failed to lock |
| 108 | * 0 got the lock |
| 109 | */ |
| 110 | static inline int waking_non_zero_trylock(struct semaphore *sem) |
| 111 | { |
| 112 | int ret; |
| 113 | #ifndef CONFIG_RMW_INSNS |
| 114 | unsigned long flags; |
| 115 | |
| 116 | spin_lock_irqsave(&semaphore_wake_lock, flags); |
| 117 | ret = 1; |
| 118 | if (atomic_read(&sem->waking) > 0) { |
| 119 | atomic_dec(&sem->waking); |
| 120 | ret = 0; |
| 121 | } else |
| 122 | atomic_inc(&sem->count); |
| 123 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| 124 | #else |
| 125 | int tmp1, tmp2; |
| 126 | |
| 127 | __asm__ __volatile__ |
| 128 | ("1: movel %1,%2\n" |
| 129 | " jle 2f\n" |
| 130 | " subql #1,%2\n" |
| 131 | " casl %1,%2,%3\n" |
| 132 | " jne 1b\n" |
| 133 | " moveq #0,%0\n" |
| 134 | "2:" |
| 135 | : "=d" (ret), "=d" (tmp1), "=d" (tmp2) |
| 136 | : "m" (sem->waking), "0" (1), "1" (sem->waking)); |
| 137 | if (ret) |
| 138 | atomic_inc(&sem->count); |
| 139 | #endif |
| 140 | return ret; |
| 141 | } |
| 142 | |
| 143 | #endif |