diff --git a/sys/alpha/alpha/mp_machdep.c b/sys/alpha/alpha/mp_machdep.c
index 393802da1651..c2e2fccb42d9 100644
--- a/sys/alpha/alpha/mp_machdep.c
+++ b/sys/alpha/alpha/mp_machdep.c
@@ -282,6 +282,7 @@ globaldata_init(struct globaldata *globaldata, int cpuno, size_t sz)
 	globaldata->gd_other_cpus = all_cpus & ~(1 << cpuno);
 	globaldata->gd_next_asn = 0;
 	globaldata->gd_current_asngen = 1;
+	globaldata->gd_cpuid = cpuno;
 	cpuno_to_globaldata[cpuno] = globaldata;
 }
 
@@ -369,10 +370,14 @@ s_lock_try(struct simplelock *lkp)
 /* lock around the MP rendezvous */
 static struct simplelock smp_rv_lock;
 
+/* only 1 CPU can panic at a time :) */
+struct simplelock	panic_lock;
+
 static void
 init_locks(void)
 {
 	s_lock_init(&smp_rv_lock);
+	s_lock_init(&panic_lock);
 }
 
 void
diff --git a/sys/alpha/include/globaldata.h b/sys/alpha/include/globaldata.h
index 361ae09109c5..5fd6c5948564 100644
--- a/sys/alpha/include/globaldata.h
+++ b/sys/alpha/include/globaldata.h
@@ -62,6 +62,7 @@ struct globaldata {
 	u_int		gd_astpending;
 	SLIST_ENTRY(globaldata) gd_allcpu;
 	int		gd_witness_spin_check;
+	u_int		gd_cpuid;
 #ifdef KTR_PERCPU
 	volatile int	gd_ktr_idx;		/* Index into trace table */
 	char		*gd_ktr_buf;
diff --git a/sys/alpha/include/lock.h b/sys/alpha/include/lock.h
index f2e3448e2de3..ebca86165b28 100644
--- a/sys/alpha/include/lock.h
+++ b/sys/alpha/include/lock.h
@@ -55,6 +55,8 @@ s_unlock(struct simplelock *lkp)
 	lkp->lock_data = 0;
 }
 
+extern struct simplelock	panic_lock;
+
 #if !defined(SIMPLELOCK_DEBUG) && MAXCPU > 1
 /*
  * This set of defines turns on the real functions in i386/isa/apic_ipl.s.
diff --git a/sys/alpha/include/pcpu.h b/sys/alpha/include/pcpu.h
index 361ae09109c5..5fd6c5948564 100644
--- a/sys/alpha/include/pcpu.h
+++ b/sys/alpha/include/pcpu.h
@@ -62,6 +62,7 @@ struct globaldata {
 	u_int		gd_astpending;
 	SLIST_ENTRY(globaldata) gd_allcpu;
 	int		gd_witness_spin_check;
+	u_int		gd_cpuid;
 #ifdef KTR_PERCPU
 	volatile int	gd_ktr_idx;		/* Index into trace table */
 	char		*gd_ktr_buf;
diff --git a/sys/powerpc/include/globaldata.h b/sys/powerpc/include/globaldata.h
index 361ae09109c5..5fd6c5948564 100644
--- a/sys/powerpc/include/globaldata.h
+++ b/sys/powerpc/include/globaldata.h
@@ -62,6 +62,7 @@ struct globaldata {
 	u_int		gd_astpending;
 	SLIST_ENTRY(globaldata) gd_allcpu;
 	int		gd_witness_spin_check;
+	u_int		gd_cpuid;
 #ifdef KTR_PERCPU
 	volatile int	gd_ktr_idx;		/* Index into trace table */
 	char		*gd_ktr_buf;
diff --git a/sys/powerpc/include/pcpu.h b/sys/powerpc/include/pcpu.h
index 361ae09109c5..5fd6c5948564 100644
--- a/sys/powerpc/include/pcpu.h
+++ b/sys/powerpc/include/pcpu.h
@@ -62,6 +62,7 @@ struct globaldata {
 	u_int		gd_astpending;
 	SLIST_ENTRY(globaldata) gd_allcpu;
 	int		gd_witness_spin_check;
+	u_int		gd_cpuid;
 #ifdef KTR_PERCPU
 	volatile int	gd_ktr_idx;		/* Index into trace table */
 	char		*gd_ktr_buf;