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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef __LINUX_SMPLOCK_H |
| 2 | #define __LINUX_SMPLOCK_H |
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| 3 | |||
| 4 | #include <linux/config.h> |
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| 5 | #include <linux/sched.h> |
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| 6 | #include <linux/spinlock.h> |
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| 7 | |||
| 8 | #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) |
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| 9 | |||
| 10 | extern spinlock_t kernel_flag; |
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| 11 | |||
| 12 | #define kernel_locked() (current->lock_depth >= 0) |
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| 13 | |||
| 14 | #define get_kernel_lock() spin_lock(&kernel_flag) |
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| 15 | #define put_kernel_lock() spin_unlock(&kernel_flag) |
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| 16 | |||
| 17 | /* |
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| 18 | * Release global kernel lock. |
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| 19 | */ |
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| 20 | static inline void release_kernel_lock(struct task_struct *task) |
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| 21 | { |
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| 22 | if (unlikely(task->lock_depth >= 0)) |
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| 23 | put_kernel_lock(); |
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| 24 | } |
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| 25 | |||
| 26 | /* |
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| 27 | * Re-acquire the kernel lock |
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| 28 | */ |
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| 29 | static inline void reacquire_kernel_lock(struct task_struct *task) |
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| 30 | { |
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| 31 | if (unlikely(task->lock_depth >= 0)) |
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| 32 | get_kernel_lock(); |
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| 33 | } |
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| 34 | |||
| 35 | /* |
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| 36 | * Getting the big kernel lock. |
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| 37 | * |
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| 38 | * This cannot happen asynchronously, |
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| 39 | * so we only need to worry about other |
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| 40 | * CPU's. |
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| 41 | */ |
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| 42 | static inline void lock_kernel(void) |
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| 43 | { |
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| 44 | int depth = current->lock_depth+1; |
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| 45 | if (likely(!depth)) |
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| 46 | get_kernel_lock(); |
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| 47 | current->lock_depth = depth; |
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| 48 | } |
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| 49 | |||
| 50 | static inline void unlock_kernel(void) |
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| 51 | { |
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| 52 | if (unlikely(current->lock_depth < 0)) |
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| 53 | BUG(); |
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| 54 | if (likely(--current->lock_depth < 0)) |
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| 55 | put_kernel_lock(); |
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| 56 | } |
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| 57 | |||
| 58 | #else |
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| 59 | |||
| 60 | #define lock_kernel() do { } while(0) |
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| 61 | #define unlock_kernel() do { } while(0) |
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| 62 | #define release_kernel_lock(task) do { } while(0) |
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| 63 | #define reacquire_kernel_lock(task) do { } while(0) |
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| 64 | #define kernel_locked() 1 |
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| 65 | |||
| 66 | #endif /* CONFIG_SMP || CONFIG_PREEMPT */ |
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| 67 | #endif /* __LINUX_SMPLOCK_H */ |