diff --git a/sys/powerpc/include/atomic.h b/sys/powerpc/include/atomic.h
index 710a50f5aba..1c492bbf861 100644
--- a/sys/powerpc/include/atomic.h
+++ b/sys/powerpc/include/atomic.h
@@ -65,6 +65,15 @@
 #define __ATOMIC_ACQ()	__asm __volatile("isync" : : : "memory")
 #endif
 
+#if !defined(__powerpc64__) && defined(_KERNEL)
+/*
+ * 64-bit atomic emulation using a global lock.
+ * Restricted to kernel use.
+ */
+#include <sys/mutex.h>
+extern struct mtx ppc32_atomic64_mtx;
+#endif
+
 static __inline void
 powerpc_lwsync(void)
 {
@@ -114,25 +123,33 @@ powerpc_lwsync(void)
 	: "r" (p), "r" (v), "m" (*p)				\
 	: "cr0", "memory")					\
     /* __atomic_add_long */
+
+#ifdef _KERNEL
+#define __atomic_add_int64_t(p, v, t)				\
+	mtx_lock_spin(&ppc32_atomic64_mtx);			\
+	*p += v;						\
+	mtx_unlock_spin(&ppc32_atomic64_mtx);			\
+	/* __atomic_add_int64_t*/
+#endif
 #endif
 
 #define	_ATOMIC_ADD(type)					\
     static __inline void					\
     atomic_add_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_add_##type(p, v, t);				\
     }								\
 								\
     static __inline void					\
     atomic_add_acq_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_add_##type(p, v, t);				\
 	__ATOMIC_ACQ();						\
     }								\
 								\
     static __inline void					\
     atomic_add_rel_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__ATOMIC_REL();						\
 	__atomic_add_##type(p, v, t);				\
     }								\
@@ -154,6 +171,14 @@ _ATOMIC_ADD(long)
 #define	atomic_add_acq_ptr	atomic_add_acq_long
 #define	atomic_add_rel_ptr	atomic_add_rel_long
 #else
+#ifdef _KERNEL
+_ATOMIC_ADD(int64_t)
+
+#define	atomic_add_64		atomic_add_int64_t
+#define	atomic_add_acq_64	atomic_add_acq_int64_t
+#define	atomic_add_rel_64	atomic_add_rel_int64_t
+#endif
+
 #define	atomic_add_ptr		atomic_add_int
 #define	atomic_add_acq_ptr	atomic_add_acq_int
 #define	atomic_add_rel_ptr	atomic_add_rel_int
@@ -200,25 +225,33 @@ _ATOMIC_ADD(long)
 	: "r" (p), "r" (v), "m" (*p)				\
 	: "cr0", "memory")					\
     /* __atomic_clear_long */
+
+#ifdef _KERNEL
+#define __atomic_clear_int64_t(p, v, t)				\
+        mtx_lock_spin(&ppc32_atomic64_mtx);			\
+        *p &= ~v;						\
+        mtx_unlock_spin(&ppc32_atomic64_mtx);			\
+	/* __atomic_clear_int64_t */
+#endif
 #endif
 
 #define	_ATOMIC_CLEAR(type)					\
     static __inline void					\
     atomic_clear_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_clear_##type(p, v, t);				\
     }								\
 								\
     static __inline void					\
     atomic_clear_acq_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_clear_##type(p, v, t);				\
 	__ATOMIC_ACQ();						\
     }								\
 								\
     static __inline void					\
     atomic_clear_rel_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__ATOMIC_REL();						\
 	__atomic_clear_##type(p, v, t);				\
     }								\
@@ -241,6 +274,14 @@ _ATOMIC_CLEAR(long)
 #define	atomic_clear_acq_ptr	atomic_clear_acq_long
 #define	atomic_clear_rel_ptr	atomic_clear_rel_long
 #else
+#ifdef _KERNEL
+_ATOMIC_CLEAR(int64_t)
+
+#define	atomic_clear_64		atomic_clear_int64_t
+#define	atomic_clear_acq_64	atomic_clear_acq_int64_t
+#define	atomic_clear_rel_64	atomic_clear_rel_int64_t
+#endif
+
 #define	atomic_clear_ptr	atomic_clear_int
 #define	atomic_clear_acq_ptr	atomic_clear_acq_int
 #define	atomic_clear_rel_ptr	atomic_clear_rel_int
@@ -302,25 +343,33 @@ _ATOMIC_CLEAR(long)
 	: "r" (p), "r" (v), "m" (*p)				\
 	: "cr0", "memory")					\
     /* __atomic_set_long */
+
+#ifdef _KERNEL
+#define __atomic_set_int64_t(p, v, t)				\
+	mtx_lock_spin(&ppc32_atomic64_mtx);			\
+	*p |= v;						\
+	mtx_unlock_spin(&ppc32_atomic64_mtx);			\
+	/* __atomic_set_int64_t */
+#endif
 #endif
 
 #define	_ATOMIC_SET(type)					\
     static __inline void					\
     atomic_set_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_set_##type(p, v, t);				\
     }								\
 								\
     static __inline void					\
     atomic_set_acq_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__atomic_set_##type(p, v, t);				\
 	__ATOMIC_ACQ();						\
     }								\
 								\
     static __inline void					\
     atomic_set_rel_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;						\
+	u_##type t __unused;					\
 	__ATOMIC_REL();						\
 	__atomic_set_##type(p, v, t);				\
     }								\
@@ -342,6 +391,14 @@ _ATOMIC_SET(long)
 #define	atomic_set_acq_ptr	atomic_set_acq_long
 #define	atomic_set_rel_ptr	atomic_set_rel_long
 #else
+#ifdef _KERNEL
+_ATOMIC_SET(int64_t)
+
+#define	atomic_set_64		atomic_set_int64_t
+#define	atomic_set_acq_64	atomic_set_acq_int64_t
+#define	atomic_set_rel_64	atomic_set_rel_int64_t
+#endif
+
 #define	atomic_set_ptr		atomic_set_int
 #define	atomic_set_acq_ptr	atomic_set_acq_int
 #define	atomic_set_rel_ptr	atomic_set_rel_int
@@ -388,25 +445,32 @@ _ATOMIC_SET(long)
 	: "r" (p), "r" (v), "m" (*p)				\
 	: "cr0", "memory")					\
     /* __atomic_subtract_long */
+#ifdef _KERNEL
+#define __atomic_subtract_int64_t(p, v, t)			\
+	mtx_lock_spin(&ppc32_atomic64_mtx);			\
+	*p -= v;						\
+	mtx_unlock_spin(&ppc32_atomic64_mtx);			\
+	/* __atomic_subtract_int64_t */
+#endif
 #endif
 
 #define	_ATOMIC_SUBTRACT(type)						\
     static __inline void						\
     atomic_subtract_##type(volatile u_##type *p, u_##type v) {		\
-	u_##type t;							\
+	u_##type t __unused;						\
 	__atomic_subtract_##type(p, v, t);				\
     }									\
 									\
     static __inline void						\
     atomic_subtract_acq_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;							\
+	u_##type t __unused;						\
 	__atomic_subtract_##type(p, v, t);				\
 	__ATOMIC_ACQ();							\
     }									\
 									\
     static __inline void						\
     atomic_subtract_rel_##type(volatile u_##type *p, u_##type v) {	\
-	u_##type t;							\
+	u_##type t __unused;						\
 	__ATOMIC_REL();							\
 	__atomic_subtract_##type(p, v, t);				\
     }									\
@@ -428,6 +492,14 @@ _ATOMIC_SUBTRACT(long)
 #define	atomic_subtract_acq_ptr	atomic_subtract_acq_long
 #define	atomic_subtract_rel_ptr	atomic_subtract_rel_long
 #else
+#ifdef _KERNEL
+_ATOMIC_SUBTRACT(int64_t)
+
+#define	atomic_subtract_64	atomic_subtract_int64_t
+#define	atomic_subtract_acq_64	atomic_subtract_acq_int64_t
+#define	atomic_subtract_rel_64	atomic_subtract_rel_int64_t
+#endif
+
 #define	atomic_subtract_ptr	atomic_subtract_int
 #define	atomic_subtract_acq_ptr	atomic_subtract_acq_int
 #define	atomic_subtract_rel_ptr	atomic_subtract_rel_int
@@ -481,6 +553,19 @@ atomic_readandclear_long(volatile u_long *addr)
 
 	return (result);
 }
+#else
+#ifdef _KERNEL
+static __inline uint64_t
+atomic_readandclear_64(volatile uint64_t *addr)
+{
+	uint64_t result;
+	mtx_lock_spin(&ppc32_atomic64_mtx);
+	mb();
+	result = *addr;
+	mtx_unlock_spin(&ppc32_atomic64_mtx);
+	return (result);
+}
+#endif
 #endif
 
 #define	atomic_readandclear_32		atomic_readandclear_int
@@ -699,6 +784,20 @@ atomic_cmpset_long(volatile u_long* p, u_long cmpval, u_long newval)
 
 	return (ret);
 }
+#if defined(_KERNEL) && !defined(__powerpc64__)
+static __inline int
+atomic_cmpset_int64_t(volatile uint64_t *p, uint64_t cmpval, uint64_t newval)
+{
+	int ret = 0;
+	mtx_lock_spin(&ppc32_atomic64_mtx);
+	if (*p == cmpval) {
+		*p = newval;
+		ret = 1;
+	}
+	mtx_unlock_spin(&ppc32_atomic64_mtx);
+	return (ret);
+}
+#endif
 
 #define	ATOMIC_CMPSET_ACQ_REL(type) \
     static __inline int \
@@ -744,6 +843,13 @@ ATOMIC_CMPSET_ACQ_REL(long);
 #define	atomic_cmpset_acq_ptr	atomic_cmpset_acq_long
 #define	atomic_cmpset_rel_ptr	atomic_cmpset_rel_long
 #else
+#ifdef _KERNEL
+ATOMIC_CMPSET_ACQ_REL(int64_t);
+#define	atomic_cmpset_64	atomic_cmpset_int64_t
+#define	atomic_cmpset_acq_64	atomic_cmpset_acq_int64_t
+#define	atomic_cmpset_rel_64	atomic_cmpset_rel_int64_t
+#endif
+
 #define	atomic_cmpset_ptr	atomic_cmpset_int
 #define	atomic_cmpset_acq_ptr	atomic_cmpset_acq_int
 #define	atomic_cmpset_rel_ptr	atomic_cmpset_rel_int
@@ -868,6 +974,25 @@ atomic_fcmpset_long(volatile u_long *p, u_long *cmpval, u_long newval)
 	return (ret);
 }
 
+#if defined(_KERNEL) && !defined(__powerpc64__)
+static __inline int
+atomic_fcmpset_int64_t(volatile uint64_t *p, uint64_t *cmpval, uint64_t newval)
+{
+	int ret;
+	mtx_lock_spin(&ppc32_atomic64_mtx);
+	if (*p == *cmpval) {
+		*p = newval;
+		ret = 1;
+	}
+	else {
+		*cmpval = newval;
+		ret = 0;
+	}
+	mtx_unlock_spin(&ppc32_atomic64_mtx);
+	return (ret);
+}
+#endif
+
 #define	ATOMIC_FCMPSET_ACQ_REL(type) \
     static __inline int \
     atomic_fcmpset_acq_##type(volatile u_##type *p, \
@@ -911,6 +1036,13 @@ ATOMIC_FCMPSET_ACQ_REL(long);
 #define	atomic_fcmpset_acq_ptr	atomic_fcmpset_acq_long
 #define	atomic_fcmpset_rel_ptr	atomic_fcmpset_rel_long
 #else
+#ifdef _KERNEL
+ATOMIC_FCMPSET_ACQ_REL(int64_t);
+#define	atomic_fcmpset_64	atomic_fcmpset_int64_t;
+#define	atomic_fcmpset_acq_64	atomic_fcmpset_acq_int64_t;
+#define	atomic_fcmpset_rel_64	atomic_fcmpset_rel_int64_t;
+#endif
+
 #define	atomic_fcmpset_ptr	atomic_fcmpset_int
 #define	atomic_fcmpset_acq_ptr	atomic_fcmpset_acq_int
 #define	atomic_fcmpset_rel_ptr	atomic_fcmpset_rel_int
@@ -970,6 +1102,19 @@ atomic_swap_64(volatile u_long *p, u_long v)
 
 	return (prev);
 }
+#else
+#ifdef _KERNEL
+static __inline uint64_t
+atomic_swap_64(volatile uint64_t *p, uint64_t v)
+{
+	uint64_t prev;
+	mtx_lock_spin(&ppc32_atomic64_mtx);
+	prev = *p;
+	*p = v;
+	mtx_unlock_spin(&ppc32_atomic64_mtx);
+	return (prev);
+}
+#endif
 #endif
 
 #define	atomic_fetchadd_32	atomic_fetchadd_int
diff --git a/sys/powerpc/powerpc/machdep.c b/sys/powerpc/powerpc/machdep.c
index 16e440b96b4..6fc805c1f7e 100644
--- a/sys/powerpc/powerpc/machdep.c
+++ b/sys/powerpc/powerpc/machdep.c
@@ -139,6 +139,10 @@ int cacheline_size = 32;
 #endif
 int hw_direct_map = 1;
 
+#ifndef __powerpc64__
+struct mtx ppc32_atomic64_mtx;
+#endif
+
 #ifdef BOOKE
 extern vm_paddr_t kernload;
 #endif
@@ -401,6 +405,10 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
 	 */
 	mutex_init();
 
+#ifndef __powerpc64__
+	mtx_init(&ppc32_atomic64_mtx, "atomic64", NULL, MTX_SPIN);
+#endif
+
 	/*
 	 * Install the OF client interface
 	 */