forked from mirrors/linux
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
#ifndef __LINUX_SMPLOCK_H
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#define __LINUX_SMPLOCK_H
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#ifdef CONFIG_LOCK_KERNEL
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#define kernel_locked() (current->lock_depth >= 0)
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extern int __lockfunc __reacquire_kernel_lock(void);
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extern void __lockfunc __release_kernel_lock(void);
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/*
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* Release/re-acquire global kernel lock for the scheduler
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*/
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#define release_kernel_lock(tsk) do { \
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if (unlikely((tsk)->lock_depth >= 0)) \
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__release_kernel_lock(); \
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} while (0)
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/*
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* Non-SMP kernels will never block on the kernel lock,
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* so we are better off returning a constant zero from
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* reacquire_kernel_lock() so that the compiler can see
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* it at compile-time.
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*/
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#if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_BKL)
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# define return_value_on_smp return
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#else
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# define return_value_on_smp
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#endif
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static inline int reacquire_kernel_lock(struct task_struct *task)
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{
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if (unlikely(task->lock_depth >= 0))
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return_value_on_smp __reacquire_kernel_lock();
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return 0;
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}
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extern void __lockfunc lock_kernel(void) __acquires(kernel_lock);
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extern void __lockfunc unlock_kernel(void) __releases(kernel_lock);
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#else
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#define lock_kernel() do { } while(0)
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#define unlock_kernel() do { } while(0)
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#define release_kernel_lock(task) do { } while(0)
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#define reacquire_kernel_lock(task) 0
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#define kernel_locked() 1
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#endif /* CONFIG_LOCK_KERNEL */
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#endif /* __LINUX_SMPLOCK_H */
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