Fix hang during secondary CPU sibling init caused by nested spinlocks.

[coreboot.git] / src / cpu / x86 / lapic / lapic_cpu_init.c

diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c
index 7c40f6a3c00eb8eccd476c4b5feb72b30a62a811..7f348790e5faaca18fec0667da213633aabb65b0 100644 (file)
--- a/src/cpu/x86/lapic/lapic_cpu_init.c
+++ b/src/cpu/x86/lapic/lapic_cpu_init.c
@@ -227,20 +227,26 @@ int start_cpu(device_t cpu)
 }
 
 /* C entry point of secondary cpus */
+
+// secondary_cpu_lock is used to serialize initialization of secondary CPUs
+// This can be used to avoid interleaved debugging messages.
+
+static spinlock_t secondary_cpu_lock = SPIN_LOCK_UNLOCKED;
+
 void secondary_cpu_init(void)
 {
        atomic_inc(&active_cpus);
+
 #if SERIAL_CPU_INIT == 1
-  #if CONFIG_MAX_CPUS>2
-       spin_lock(&start_cpu_lock);
-  #endif
+       spin_lock(&secondary_cpu_lock);
 #endif
+
        cpu_initialize();
+
 #if SERIAL_CPU_INIT == 1
-  #if CONFIG_MAX_CPUS>2
-       spin_unlock(&start_cpu_lock);
-  #endif
+       spin_unlock(&secondary_cpu_lock);
 #endif
+
        atomic_dec(&active_cpus);
        stop_this_cpu();
 }