patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / arch / ppc / lib / locks.c

diff --git a/arch/ppc/lib/locks.c b/arch/ppc/lib/locks.c
index 1f85f3e..0eaffa9 100644 (file)
--- a/arch/ppc/lib/locks.c
+++ b/arch/ppc/lib/locks.c
@@ -7,6 +7,7 @@
 #include <linux/config.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
+#include <linux/module.h>
 #include <asm/ppc_asm.h>
 #include <asm/smp.h>
 
@@ -22,7 +23,7 @@
  * since they may inhibit forward progress by other CPUs in getting
  * a lock.
  */
-unsigned long __spin_trylock(volatile unsigned long *lock)
+static inline unsigned long __spin_trylock(volatile unsigned long *lock)
 {
        unsigned long ret;
 
@@ -62,6 +63,7 @@ void _raw_spin_lock(spinlock_t *lock)
        lock->owner_pc = (unsigned long)__builtin_return_address(0);
        lock->owner_cpu = cpu;
 }
+EXPORT_SYMBOL(_raw_spin_lock);
 
 int _raw_spin_trylock(spinlock_t *lock)
 {
@@ -71,6 +73,7 @@ int _raw_spin_trylock(spinlock_t *lock)
        lock->owner_pc = (unsigned long)__builtin_return_address(0);
        return 1;
 }
+EXPORT_SYMBOL(_raw_spin_trylock);
 
 void _raw_spin_unlock(spinlock_t *lp)
 {
@@ -86,6 +89,7 @@ void _raw_spin_unlock(spinlock_t *lp)
        wmb();
        lp->lock = 0;
 }
+EXPORT_SYMBOL(_raw_spin_unlock);
 
 
 /*
@@ -119,6 +123,7 @@ again:
        }
        wmb();
 }
+EXPORT_SYMBOL(_raw_read_lock);
 
 void _raw_read_unlock(rwlock_t *rw)
 {
@@ -129,6 +134,7 @@ void _raw_read_unlock(rwlock_t *rw)
        wmb();
        atomic_dec((atomic_t *) &(rw)->lock);
 }
+EXPORT_SYMBOL(_raw_read_unlock);
 
 void _raw_write_lock(rwlock_t *rw)
 {
@@ -169,6 +175,22 @@ again:
        }
        wmb();
 }
+EXPORT_SYMBOL(_raw_write_lock);
+
+int _raw_write_trylock(rwlock_t *rw)
+{
+       if (test_and_set_bit(31, &(rw)->lock)) /* someone has a write lock */
+               return 0;
+
+       if ((rw)->lock & ~(1<<31)) {    /* someone has a read lock */
+               /* clear our write lock and wait for reads to go away */
+               clear_bit(31,&(rw)->lock);
+               return 0;
+       }
+       wmb();
+       return 1;
+}
+EXPORT_SYMBOL(_raw_write_trylock);
 
 void _raw_write_unlock(rwlock_t *rw)
 {
@@ -179,5 +201,6 @@ void _raw_write_unlock(rwlock_t *rw)
        wmb();
        clear_bit(31,&(rw)->lock);
 }
+EXPORT_SYMBOL(_raw_write_unlock);
 
 #endif