diff -urN NVIDIA-Linux-x86-185.18.36-pkg1/usr/src/nv/nv-linux.h NVIDIA-Linux-x86-185.18.36-pkg1-new/usr/src/nv/nv-linux.h
--- NVIDIA-Linux-x86-185.18.36-pkg1/usr/src/nv/nv-linux.h	2009-09-29 13:59:37.000000000 +0100
+++ NVIDIA-Linux-x86-185.18.36-pkg1-new/usr/src/nv/nv-linux.h	2009-09-29 14:48:09.000000000 +0100
@@ -720,9 +720,26 @@
 #define nv_down(lock)                   down(&lock)
 #define nv_up(lock)                     up(&lock)
 
+#if defined(CONFIG_PREEMPT_RT) && \
+  (LINUX_VERSION_CODE == KERNEL_VERSION(2, 6, 31))
+#  define nv_spin_lock_init(lock)              atomic_spin_lock_init(lock)
+#  define nv_spin_lock_irqsave(lock, irq)      atomic_spin_lock_irqsave(lock, irq)
+#  define nv_spin_unlock_irqrestore(lock, irq) atomic_spin_unlock_irqrestore(lock, irq)
+#else
+#  define nv_spin_lock_init(lock)              spin_lock_init(lock)
+#  define nv_spin_lock_irqsave(lock, irq)      spin_lock_irqsave(lock, irq)
+#  define nv_spin_unlock_irqrestore(lock, irq) spin_unlock_irqrestore(lock, irq)
+#endif
+
 #if defined(CONFIG_PREEMPT_RT)
-#define NV_INIT_MUTEX(mutex) init_MUTEX(mutex)
+#if LINUX_VERSION_CODE == KERNEL_VERSION(2, 6, 31)
+#  define nv_spinlock_t atomic_spinlock_t
+#else
+#  define nv_spinlock_t raw_spinlock_t
+#endif
+#define NV_INIT_MUTEX(mutex) semaphore_init(mutex)
 #else
+#define nv_spinlock_t spinlock_t
 #if !defined(__SEMAPHORE_INITIALIZER) && defined(__COMPAT_SEMAPHORE_INITIALIZER)
 #define __SEMAPHORE_INITIALIZER __COMPAT_SEMAPHORE_INITIALIZER
 #endif
diff -urN NVIDIA-Linux-x86-185.18.36-pkg1/usr/src/nv/os-interface.c NVIDIA-Linux-x86-185.18.36-pkg1-new/usr/src/nv/os-interface.c
--- NVIDIA-Linux-x86-185.18.36-pkg1/usr/src/nv/os-interface.c	2009-09-29 13:59:37.000000000 +0100
+++ NVIDIA-Linux-x86-185.18.36-pkg1-new/usr/src/nv/os-interface.c	2009-09-29 14:39:51.000000000 +0100
@@ -87,11 +87,7 @@
 {
     nv_stack_t        *sp;
     struct completion  completion;
-#if defined(CONFIG_PREEMPT_RT)
-    raw_spinlock_t     lock;
-#else
-    spinlock_t         lock;
-#endif
+    nv_spinlock_t      lock;
     S032               count;
 } os_sema_t;
 
@@ -127,7 +123,7 @@
     os_sema = (os_sema_t *)*ppSema;
     os_sema->sp = sp;
     init_completion(&os_sema->completion);
-    spin_lock_init(&os_sema->lock);
+    nv_spin_lock_init(&os_sema->lock);
     os_sema->count = 1;
 
     return RM_OK;
@@ -171,18 +167,18 @@
     os_sema_t *os_sema = (os_sema_t *)pSema;
     unsigned long old_irq;
 
-    spin_lock_irqsave(&os_sema->lock, old_irq);
+    nv_spin_lock_irqsave(&os_sema->lock, old_irq);
     if (os_sema->count <= 0)
     {
         os_sema->count--;
-        spin_unlock_irqrestore(&os_sema->lock, old_irq);
+        nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
         wait_for_completion(&os_sema->completion);
     }
     else
     {
         os_sema->count--;
         rm_disable_interrupts(os_sema->sp);
-        spin_unlock_irqrestore(&os_sema->lock, old_irq);
+        nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
     }
 
     return RM_OK;
@@ -205,17 +201,17 @@
     os_sema_t *os_sema = (os_sema_t *)pSema;
     unsigned long old_irq;
 
-    spin_lock_irqsave(&os_sema->lock, old_irq);
+    nv_spin_lock_irqsave(&os_sema->lock, old_irq);
     if (os_sema->count <= 0)
     {
-        spin_unlock_irqrestore(&os_sema->lock, old_irq);
+        nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
         return FALSE;
     }
     else
     {
         os_sema->count--;
         rm_disable_interrupts(os_sema->sp);
-        spin_unlock_irqrestore(&os_sema->lock, old_irq);
+        nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
         return TRUE;
     }
 
@@ -239,7 +235,7 @@
     unsigned long old_irq;
     BOOL doWakeup;
 
-    spin_lock_irqsave(&os_sema->lock, old_irq);
+    nv_spin_lock_irqsave(&os_sema->lock, old_irq);
     if (os_sema->count < 0)
     {
         doWakeup = TRUE;
@@ -250,7 +246,7 @@
         rm_enable_interrupts(os_sema->sp);
     }
     os_sema->count++;
-    spin_unlock_irqrestore(&os_sema->lock, old_irq);
+    nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
 
     if (doWakeup)
         complete(&os_sema->completion);
@@ -1319,7 +1315,7 @@
     unsigned long oldIrql;
 
     os_sema = (os_sema_t *) pSema;
-    spin_lock_irqsave(&os_sema->lock, oldIrql);
+    nv_spin_lock_irqsave(&os_sema->lock, oldIrql);
 
     return oldIrql;
 }
@@ -1330,7 +1326,7 @@
     unsigned long old_irq = (unsigned long) oldIrql;
 
     os_sema = (os_sema_t *) pSema;
-    spin_unlock_irqrestore(&os_sema->lock, old_irq);
+    nv_spin_unlock_irqrestore(&os_sema->lock, old_irq);
 }