#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
-
-#ifdef CONFIG_PREEMPT_BKL
-/*
- * The 'big kernel semaphore'
- *
- * This mutex is taken and released recursively by lock_kernel()
- * and unlock_kernel(). It is transparently dropped and reacquired
- * over schedule(). It is used to protect legacy code that hasn't
- * been migrated to a proper locking design yet.
- *
- * Note: code locked by this semaphore will only be serialized against
- * other code using the same locking facility. The code guarantees that
- * the task remains on the same CPU.
- *
- * Don't use in new code.
- */
-static DECLARE_MUTEX(kernel_sem);
-
-/*
- * Re-acquire the kernel semaphore.
- *
- * This function is called with preemption off.
- *
- * We are executing in schedule() so the code must be extremely careful
- * about recursion, both due to the down() and due to the enabling of
- * preemption. schedule() will re-check the preemption flag after
- * reacquiring the semaphore.
- */
-int __lockfunc __reacquire_kernel_lock(void)
-{
- struct task_struct *task = current;
- int saved_lock_depth = task->lock_depth;
-
- BUG_ON(saved_lock_depth < 0);
-
- task->lock_depth = -1;
- preempt_enable_no_resched();
-
- down(&kernel_sem);
-
- preempt_disable();
- task->lock_depth = saved_lock_depth;
-
- return 0;
-}
-
-void __lockfunc __release_kernel_lock(void)
-{
- up(&kernel_sem);
-}
-
-/*
- * Getting the big kernel semaphore.
- */
-void __lockfunc lock_kernel(void)
-{
- struct task_struct *task = current;
- int depth = task->lock_depth + 1;
-
- if (likely(!depth))
- /*
- * No recursion worries - we set up lock_depth _after_
- */
- down(&kernel_sem);
-
- task->lock_depth = depth;
-}
-
-void __lockfunc unlock_kernel(void)
-{
- struct task_struct *task = current;
-
- BUG_ON(task->lock_depth < 0);
-
- if (likely(--task->lock_depth < 0))
- up(&kernel_sem);
-}
-
-#else
+#include <linux/semaphore.h>
/*
* The 'big kernel lock'
}
/*
- * These are the BKL spinlocks - we try to be polite about preemption.
+ * These are the BKL spinlocks - we try to be polite about preemption.
* If SMP is not on (ie UP preemption), this all goes away because the
* _raw_spin_trylock() will always succeed.
*/
__unlock_kernel();
}
-#endif
-
EXPORT_SYMBOL(lock_kernel);
EXPORT_SYMBOL(unlock_kernel);