diff --git a/sys/arm64/arm64/efirt_machdep.c b/sys/arm64/arm64/efirt_machdep.c
--- a/sys/arm64/arm64/efirt_machdep.c
+++ b/sys/arm64/arm64/efirt_machdep.c
@@ -144,13 +144,8 @@
 vm_offset_t
 efi_phys_to_kva(vm_paddr_t paddr)
 {
-	vm_offset_t vaddr;
-
-	if (PHYS_IN_DMAP(paddr)) {
-		vaddr = PHYS_TO_DMAP(paddr);
-		if (pmap_klookup(vaddr, NULL))
-			return (vaddr);
-	}
+	if (PHYS_IN_DMAP(paddr))
+		return (PHYS_TO_DMAP(paddr));
 
 	/* TODO: Map memory not in the DMAP */
 
diff --git a/sys/arm64/arm64/machdep.c b/sys/arm64/arm64/machdep.c
--- a/sys/arm64/arm64/machdep.c
+++ b/sys/arm64/arm64/machdep.c
@@ -444,7 +444,7 @@
 	/*
 	 * If it is within the DMAP region and is writable use that.
 	 */
-	if (PHYS_IN_DMAP(pa)) {
+	if (PHYS_IN_DMAP_RANGE(pa)) {
 		addr = (void *)PHYS_TO_DMAP(pa);
 		if (PAR_SUCCESS(arm64_address_translate_s1e1w(
 		    (vm_offset_t)addr))) {
diff --git a/sys/arm64/arm64/minidump_machdep.c b/sys/arm64/arm64/minidump_machdep.c
--- a/sys/arm64/arm64/minidump_machdep.c
+++ b/sys/arm64/arm64/minidump_machdep.c
@@ -202,7 +202,8 @@
 				if ((l3e & ATTR_DESCR_MASK) != L3_PAGE)
 					continue;
 				pa = PTE_TO_PHYS(l3e);
-				if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
+				if (PHYS_IN_DMAP_RANGE(pa) &&
+				    vm_phys_is_dumpable(pa))
 					vm_page_dump_add(state->dump_bitset,
 					    pa);
 			}
@@ -216,7 +217,7 @@
 	dumpsize += round_page(sizeof(dump_avail));
 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
 	VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
-		if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
+		if (PHYS_IN_DMAP_RANGE(pa) && vm_phys_is_dumpable(pa))
 			dumpsize += PAGE_SIZE;
 		else
 			vm_page_dump_drop(state->dump_bitset, pa);
@@ -347,7 +348,7 @@
 			 * We always write a page, even if it is zero. If pa
 			 * is malformed, write the zeroed tmpbuffer.
 			 */
-			if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
+			if (PHYS_IN_DMAP_RANGE(pa) && vm_phys_is_dumpable(pa))
 				error = blk_write(di, NULL, pa, PAGE_SIZE);
 			else
 				error = blk_write(di, (char *)&tmpbuffer, 0,
diff --git a/sys/arm64/include/vmparam.h b/sys/arm64/include/vmparam.h
--- a/sys/arm64/include/vmparam.h
+++ b/sys/arm64/include/vmparam.h
@@ -223,9 +223,21 @@
 #define	DMAP_MIN_PHYSADDR	(dmap_phys_base)
 #define	DMAP_MAX_PHYSADDR	(dmap_phys_max)
 
-/* True if pa is in the dmap range */
-#define	PHYS_IN_DMAP(pa)	((pa) >= DMAP_MIN_PHYSADDR && \
+/*
+ * Checks to see if a physical address is in the DMAP range.
+ * - PHYS_IN_DMAP_RANGE will return true that may be within the DMAP range
+ *   but not accessible through the DMAP, e.g. device memory between two
+ *   DMAP physical address regions.
+ * - PHYS_IN_DMAP will check if DMAP address is mapped before returning true.
+ *
+ * PHYS_IN_DMAP_RANGE should only be used when a check on the address is
+ * performed, e.g. by checking the physical address is within phys_avail,
+ * or checking the virtual address is mapped.
+ */
+#define	PHYS_IN_DMAP_RANGE(pa)	((pa) >= DMAP_MIN_PHYSADDR && \
     (pa) < DMAP_MAX_PHYSADDR)
+#define	PHYS_IN_DMAP(pa)	(PHYS_IN_DMAP_RANGE(pa) && \
+    pmap_klookup(PHYS_TO_DMAP(pa), NULL))
 /* True if va is in the dmap range */
 #define	VIRT_IN_DMAP(va)	((va) >= DMAP_MIN_ADDRESS && \
     (va) < (dmap_max_addr))
@@ -233,7 +245,7 @@
 #define	PMAP_HAS_DMAP	1
 #define	PHYS_TO_DMAP(pa)						\
 ({									\
-	KASSERT(PHYS_IN_DMAP(pa),					\
+	KASSERT(PHYS_IN_DMAP_RANGE(pa),					\
 	    ("%s: PA out of range, PA: 0x%lx", __func__,		\
 	    (vm_paddr_t)(pa)));						\
 	((pa) - dmap_phys_base) + DMAP_MIN_ADDRESS;			\