Index: sys/amd64/amd64/busdma_machdep.c
===================================================================
--- sys/amd64/amd64/busdma_machdep.c	(revision 237444)
+++ sys/amd64/amd64/busdma_machdep.c	(working copy)
@@ -515,6 +515,12 @@
 	   (dmat->alignment < dmat->maxsize) &&
 	    dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
 		*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
+	} else if (dmat->nsegments >= btoc(dmat->maxsize) &&
+		   dmat->alignment <= PAGE_SIZE &&
+		   (dmat->boundary == 0 || dmat->boundary >= dmat->lowaddr)) {
+		/* Page-based multi-segment allocations allowed */
+		*vaddr = wiredmalloc(dmat->maxsize, M_DEVBUF, mflags,
+		    0ul, dmat->lowaddr);
 	} else {
 		/*
 		 * XXX Use Contigmalloc until it is merged into this facility
Index: sys/sys/malloc.h
===================================================================
--- sys/sys/malloc.h	(revision 237444)
+++ sys/sys/malloc.h	(working copy)
@@ -166,10 +166,18 @@
  */
 typedef void malloc_type_list_func_t(struct malloc_type *, void *);
 
+/* Allocate wired, contiguous physical memory */
 void	contigfree(void *addr, unsigned long size, struct malloc_type *type);
 void	*contigmalloc(unsigned long size, struct malloc_type *type, int flags,
 	    vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
 	    unsigned long boundary) __malloc_like;
+
+/* Allocate wired physical memory */
+#define wiredfree(addr, size, type)	contigfree((addr), (size), (type))
+void	*wiredmalloc(unsigned long size, struct malloc_type *type, int flags,
+	    vm_paddr_t low, vm_paddr_t high) __malloc_like;
+
+/* General memory allocation */
 void	free(void *addr, struct malloc_type *type);
 void	*malloc(unsigned long size, struct malloc_type *type, int flags) __malloc_like;
 void	malloc_init(void *);
Index: sys/kern/kern_malloc.c
===================================================================
--- sys/kern/kern_malloc.c	(revision 237444)
+++ sys/kern/kern_malloc.c	(working copy)
@@ -779,6 +779,41 @@
 	return (NULL);
 }
 
+
+/*
+** The wiredmalloc() function allocates size bytes of physical memory that
+** is page-aligned.  If successful, the allocation will reside between
+** physical addresses low and high.  The returned pointer points to a wired
+** kernel virtual address range of size bytes allocated from the kernel
+** virtual address (KVA) map.
+**
+** The following flags are supported:
+**   M_ZERO   - Allocated memory will be zero-filled
+**   M_NOWAIT - Return NULL rather than blocking on resource shortage
+**
+** This function has a similar interface and functionality to contigmalloc
+** except that:
+** 1) the allocated region is not guaranteed to be physically contiguous
+** 2) no boundary can be specified
+** 3) alignment is always PAGE_SIZE
+*/
+void *
+wiredmalloc(
+	unsigned long size,	/* should be size_t here and for malloc() */
+	struct malloc_type *type,
+	int flags,
+	vm_paddr_t low,
+	vm_paddr_t high)
+{
+	void *ret;
+
+	ret = (void *)kmem_alloc_attr(kernel_map, size, flags, low, high,
+	    VM_MEMATTR_DEFAULT);
+	if (ret != NULL)
+		malloc_type_allocated(type, round_page(size));
+	return (ret);
+}
+
 static int
 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
 {