Index: head/sys/powerpc/include/pcpu.h
===================================================================
--- head/sys/powerpc/include/pcpu.h
+++ head/sys/powerpc/include/pcpu.h
@@ -68,7 +68,8 @@
 	uint8_t		slbstack[1024];				\
 	struct pvo_entry *qmap_pvo;					\
 	struct mtx	qmap_lock;					\
-	char		__pad[1345];
+	uint64_t	opal_hmi_flags;					\
+	char		__pad[1337];
 
 #ifdef __powerpc64__
 #define PCPU_MD_AIM_FIELDS	PCPU_MD_AIM64_FIELDS
Index: head/sys/powerpc/powernv/opal_hmi.c
===================================================================
--- head/sys/powerpc/powernv/opal_hmi.c
+++ head/sys/powerpc/powernv/opal_hmi.c
@@ -84,13 +84,17 @@
 static int
 opal_hmi_handler2(struct trapframe *frame)
 {
-	uint64_t flags;
+	/*
+	 * Use DMAP preallocated pcpu memory to handle
+	 * the phys flags pointer.
+	 */
+	uint64_t *flags = PCPU_PTR(aim.opal_hmi_flags);
 	int err;
 
-	flags = 0;
-	err = opal_call(OPAL_HANDLE_HMI2, vtophys(&flags));
+	*flags = 0;
+	err = opal_call(OPAL_HANDLE_HMI2, DMAP_TO_PHYS((vm_offset_t)flags));
 
-	if (flags & OPAL_HMI_FLAGS_TOD_TB_FAIL)
+	if (*flags & OPAL_HMI_FLAGS_TOD_TB_FAIL)
 		panic("TOD/TB recovery failure");
 
 	if (err == OPAL_SUCCESS)