Pull video into test branch

[linux-drm-fsl-dcu.git] / arch / i386 / kernel / smp.c

diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
index 465188e2d701779878b7363fd8cf46e24ae6f4e0..5285aff8367fec481d33a7ed94c0278815202286 100644 (file)
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -693,6 +693,10 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
                put_cpu();
                return -EBUSY;
        }
+
+       /* 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);
@@ -700,3 +704,30 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
        return 0;
 }
 EXPORT_SYMBOL(smp_call_function_single);
+
+static int convert_apicid_to_cpu(int apic_id)
+{
+       int i;
+
+       for (i = 0; i < NR_CPUS; i++) {
+               if (x86_cpu_to_apicid[i] == apic_id)
+                       return i;
+       }
+       return -1;
+}
+
+int safe_smp_processor_id(void)
+{
+       int apicid, cpuid;
+
+       if (!boot_cpu_has(X86_FEATURE_APIC))
+               return 0;
+
+       apicid = hard_smp_processor_id();
+       if (apicid == BAD_APICID)
+               return 0;
+
+       cpuid = convert_apicid_to_cpu(apicid);
+
+       return cpuid >= 0 ? cpuid : 0;
+}