#ifndef __LINUX_SMPLOCK_H #define __LINUX_SMPLOCK_H #include <linux/config.h> #include <linux/sched.h> #include <linux/spinlock.h> #ifdef CONFIG_LOCK_KERNEL #define kernel_locked() (current->lock_depth >= 0) extern int __lockfunc __reacquire_kernel_lock(void); extern void __lockfunc __release_kernel_lock(void); /* * Release/re-acquire global kernel lock for the scheduler */ #define release_kernel_lock(tsk) do { \ if (unlikely((tsk)->lock_depth >= 0)) \ __release_kernel_lock(); \ } while (0) /* * Non-SMP kernels will never block on the kernel lock, * so we are better off returning a constant zero from * reacquire_kernel_lock() so that the compiler can see * it at compile-time. */ #if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_BKL) # define return_value_on_smp return #else # define return_value_on_smp #endif static inline int reacquire_kernel_lock(struct task_struct *task) { if (unlikely(task->lock_depth >= 0)) return_value_on_smp __reacquire_kernel_lock(); return 0; } extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); extern void __lockfunc unlock_kernel(void) __releases(kernel_lock); #else #define lock_kernel() do { } while(0) #define unlock_kernel() do { } while(0) #define release_kernel_lock(task) do { } while(0) #define reacquire_kernel_lock(task) 0 #define kernel_locked() 1 #endif /* CONFIG_LOCK_KERNEL */ #endif /* __LINUX_SMPLOCK_H */