Pull button into test branch

[linux-drm-fsl-dcu.git] / arch / x86_64 / kernel / smp.c

diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 4f67697f5036faf1f37222ced236c0b3a04626c7..af1ec4d23cf89131f16e5063f31c81a6810c63ba 100644 (file)
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -376,16 +376,20 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
        /* prevent preemption and reschedule on another processor */
        int me = get_cpu();
        if (cpu == me) {
-               WARN_ON(1);
                put_cpu();
-               return -EBUSY;
+               return 0;
        }
+
+       /* Can deadlock when called with interrupts disabled */
+       WARN_ON(irqs_disabled());
+
        spin_lock_bh(&call_lock);
        __smp_call_function_single(cpu, func, info, nonatomic, wait);
        spin_unlock_bh(&call_lock);
        put_cpu();
        return 0;
 }
+EXPORT_SYMBOL(smp_call_function_single);
 
 /*
  * this function sends a 'generic call function' IPI to all other CPUs