Merge branches 'release', 'asus', 'sony-laptop' and 'thinkpad' into release

[sfrench/cifs-2.6.git] / lib / kernel_lock.c

diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
index cb5490ec00f20f4fea3640275192f20d942a7fba..812dbf00844bc08a4a844bda6729377b1923a5c5 100644 (file)
--- a/lib/kernel_lock.c
+++ b/lib/kernel_lock.c
@@ -2,19 +2,18 @@
  * lib/kernel_lock.c
  *
  * This is the traditional BKL - big kernel lock. Largely
- * relegated to obsolescense, but used by various less
+ * relegated to obsolescence, but used by various less
  * important (or lazy) subsystems.
  */
 #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 reaquired
+ * 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.
  *
@@ -86,123 +85,6 @@ void __lockfunc unlock_kernel(void)
                up(&kernel_sem);
 }
 
-#else
-
-/*
- * The 'big kernel lock'
- *
- * This spinlock is taken and released recursively by lock_kernel()
- * and unlock_kernel().  It is transparently dropped and reaquired
- * over schedule().  It is used to protect legacy code that hasn't
- * been migrated to a proper locking design yet.
- *
- * Don't use in new code.
- */
-static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(kernel_flag);
-
-
-/*
- * Acquire/release the underlying lock from the scheduler.
- *
- * This is called with preemption disabled, and should
- * return an error value if it cannot get the lock and
- * TIF_NEED_RESCHED gets set.
- *
- * If it successfully gets the lock, it should increment
- * the preemption count like any spinlock does.
- *
- * (This works on UP too - _raw_spin_trylock will never
- * return false in that case)
- */
-int __lockfunc __reacquire_kernel_lock(void)
-{
-       while (!_raw_spin_trylock(&kernel_flag)) {
-               if (test_thread_flag(TIF_NEED_RESCHED))
-                       return -EAGAIN;
-               cpu_relax();
-       }
-       preempt_disable();
-       return 0;
-}
-
-void __lockfunc __release_kernel_lock(void)
-{
-       _raw_spin_unlock(&kernel_flag);
-       preempt_enable_no_resched();
-}
-
-/*
- * 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.
- */
-#ifdef CONFIG_PREEMPT
-static inline void __lock_kernel(void)
-{
-       preempt_disable();
-       if (unlikely(!_raw_spin_trylock(&kernel_flag))) {
-               /*
-                * If preemption was disabled even before this
-                * was called, there's nothing we can be polite
-                * about - just spin.
-                */
-               if (preempt_count() > 1) {
-                       _raw_spin_lock(&kernel_flag);
-                       return;
-               }
-
-               /*
-                * Otherwise, let's wait for the kernel lock
-                * with preemption enabled..
-                */
-               do {
-                       preempt_enable();
-                       while (spin_is_locked(&kernel_flag))
-                               cpu_relax();
-                       preempt_disable();
-               } while (!_raw_spin_trylock(&kernel_flag));
-       }
-}
-
-#else
-
-/*
- * Non-preemption case - just get the spinlock
- */
-static inline void __lock_kernel(void)
-{
-       _raw_spin_lock(&kernel_flag);
-}
-#endif
-
-static inline void __unlock_kernel(void)
-{
-       spin_unlock(&kernel_flag);
-}
-
-/*
- * Getting the big kernel lock.
- *
- * This cannot happen asynchronously, so we only need to
- * worry about other CPU's.
- */
-void __lockfunc lock_kernel(void)
-{
-       int depth = current->lock_depth+1;
-       if (likely(!depth))
-               __lock_kernel();
-       current->lock_depth = depth;
-}
-
-void __lockfunc unlock_kernel(void)
-{
-       BUG_ON(current->lock_depth < 0);
-       if (likely(--current->lock_depth < 0))
-               __unlock_kernel();
-}
-
-#endif
-
 EXPORT_SYMBOL(lock_kernel);
 EXPORT_SYMBOL(unlock_kernel);