diff --git a/sys/arm/arm/busdma_machdep.c b/sys/arm/arm/busdma_machdep.c
index 44bc96bed734..17cde2e60e37 100644
--- a/sys/arm/arm/busdma_machdep.c
+++ b/sys/arm/arm/busdma_machdep.c
@@ -168,11 +168,15 @@ static busdma_bufalloc_t standard_allocator;	/* Cache of standard buffers */
 MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
 
 #define	dmat_alignment(dmat)	((dmat)->alignment)
+#define	dmat_bounce_flags(dmat)	(0)
+#define	dmat_boundary(dmat)	((dmat)->boundary)
 #define	dmat_flags(dmat)	((dmat)->flags)
 #define	dmat_highaddr(dmat)	((dmat)->highaddr)
 #define	dmat_lowaddr(dmat)	((dmat)->lowaddr)
 #define	dmat_lockfunc(dmat)	((dmat)->lockfunc)
 #define	dmat_lockfuncarg(dmat)	((dmat)->lockfuncarg)
+#define	dmat_maxsegsz(dmat)	((dmat)->maxsegsz)
+#define	dmat_nsegments(dmat)	((dmat)->nsegments)
 
 #include "../../kern/subr_busdma_bounce.c"
 
@@ -842,47 +846,6 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, pmap_t pmap, bus_dmamap_t map,
 	}
 }
 
-/*
- * Add a single contiguous physical range to the segment list.
- */
-static int
-_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
-    bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
-{
-	int seg;
-
-	/*
-	 * Make sure we don't cross any boundaries.
-	 */
-	if (!vm_addr_bound_ok(curaddr, sgsize, dmat->boundary))
-		sgsize = roundup2(curaddr, dmat->boundary) - curaddr;
-
-	/*
-	 * Insert chunk into a segment, coalescing with
-	 * previous segment if possible.
-	 */
-	seg = *segp;
-	if (seg == -1) {
-		seg = 0;
-		segs[seg].ds_addr = curaddr;
-		segs[seg].ds_len = sgsize;
-	} else {
-		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
-		    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
-		    vm_addr_bound_ok(segs[seg].ds_addr,
-		    segs[seg].ds_len + sgsize, dmat->boundary))
-			segs[seg].ds_len += sgsize;
-		else {
-			if (++seg >= dmat->nsegments)
-				return (0);
-			segs[seg].ds_addr = curaddr;
-			segs[seg].ds_len = sgsize;
-		}
-	}
-	*segp = seg;
-	return (sgsize);
-}
-
 /*
  * Utility function to load a physical buffer.  segp contains
  * the starting segment on entrace, and the ending segment on exit.
diff --git a/sys/arm64/arm64/busdma_bounce.c b/sys/arm64/arm64/busdma_bounce.c
index e62794da2753..385e26e3bd8e 100644
--- a/sys/arm64/arm64/busdma_bounce.c
+++ b/sys/arm64/arm64/busdma_bounce.c
@@ -121,12 +121,16 @@ static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 static MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
 
 #define	dmat_alignment(dmat)	((dmat)->common.alignment)
+#define	dmat_bounce_flags(dmat)	((dmat)->bounce_flags)
+#define	dmat_boundary(dmat)	((dmat)->common.boundary)
 #define	dmat_domain(dmat)	((dmat)->common.domain)
 #define	dmat_flags(dmat)	((dmat)->common.flags)
 #define	dmat_highaddr(dmat)	((dmat)->common.highaddr)
 #define	dmat_lowaddr(dmat)	((dmat)->common.lowaddr)
 #define	dmat_lockfunc(dmat)	((dmat)->common.lockfunc)
 #define	dmat_lockfuncarg(dmat)	((dmat)->common.lockfuncarg)
+#define	dmat_maxsegsz(dmat)	((dmat)->common.maxsegsz)
+#define	dmat_nsegments(dmat)	((dmat)->common.nsegments)
 
 #include "../../kern/subr_busdma_bounce.c"
 
@@ -711,47 +715,6 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 	}
 }
 
-/*
- * Add a single contiguous physical range to the segment list.
- */
-static bus_size_t
-_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
-    bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
-{
-	int seg;
-
-	/*
-	 * Make sure we don't cross any boundaries.
-	 */
-	if (!vm_addr_bound_ok(curaddr, sgsize, dmat->common.boundary))
-		sgsize = roundup2(curaddr, dmat->common.boundary) - curaddr;
-
-	/*
-	 * Insert chunk into a segment, coalescing with
-	 * previous segment if possible.
-	 */
-	seg = *segp;
-	if (seg == -1) {
-		seg = 0;
-		segs[seg].ds_addr = curaddr;
-		segs[seg].ds_len = sgsize;
-	} else {
-		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
-		    (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
-		    vm_addr_bound_ok(segs[seg].ds_addr,
-		    segs[seg].ds_len + sgsize, dmat->common.boundary))
-			segs[seg].ds_len += sgsize;
-		else {
-			if (++seg >= dmat->common.nsegments)
-				return (0);
-			segs[seg].ds_addr = curaddr;
-			segs[seg].ds_len = sgsize;
-		}
-	}
-	*segp = seg;
-	return (sgsize);
-}
-
 /*
  * Utility function to load a physical buffer.  segp contains
  * the starting segment on entrace, and the ending segment on exit.
diff --git a/sys/kern/subr_busdma_bounce.c b/sys/kern/subr_busdma_bounce.c
index 77b1b358758f..a9cddcb3f39f 100644
--- a/sys/kern/subr_busdma_bounce.c
+++ b/sys/kern/subr_busdma_bounce.c
@@ -451,6 +451,54 @@ free_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 		wakeup(&bounce_map_callbacklist);
 }
 
+/*
+ * Add a single contiguous physical range to the segment list.
+ */
+static bus_size_t
+_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
+    bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
+{
+	int seg;
+
+	KASSERT(curaddr <= BUS_SPACE_MAXADDR,
+	    ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
+	    "hi %#jx",
+	    (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
+	    dmat, dmat_bounce_flags(dmat), (uintmax_t)dmat_lowaddr(dmat),
+	    (uintmax_t)dmat_highaddr(dmat)));
+
+	/*
+	 * Make sure we don't cross any boundaries.
+	 */
+	if (!vm_addr_bound_ok(curaddr, sgsize, dmat_boundary(dmat)))
+		sgsize = roundup2(curaddr, dmat_boundary(dmat)) - curaddr;
+
+	/*
+	 * Insert chunk into a segment, coalescing with
+	 * previous segment if possible.
+	 */
+	seg = *segp;
+	if (seg == -1) {
+		seg = 0;
+		segs[seg].ds_addr = curaddr;
+		segs[seg].ds_len = sgsize;
+	} else {
+		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
+		    (segs[seg].ds_len + sgsize) <= dmat_maxsegsz(dmat) &&
+		    vm_addr_bound_ok(segs[seg].ds_addr,
+		    segs[seg].ds_len + sgsize, dmat_boundary(dmat)))
+			segs[seg].ds_len += sgsize;
+		else {
+			if (++seg >= dmat_nsegments(dmat))
+				return (0);
+			segs[seg].ds_addr = curaddr;
+			segs[seg].ds_len = sgsize;
+		}
+	}
+	*segp = seg;
+	return (sgsize);
+}
+
 static void
 busdma_thread(void *dummy __unused)
 {
diff --git a/sys/powerpc/powerpc/busdma_machdep.c b/sys/powerpc/powerpc/busdma_machdep.c
index bc28619372f0..fad22d49a7f5 100644
--- a/sys/powerpc/powerpc/busdma_machdep.c
+++ b/sys/powerpc/powerpc/busdma_machdep.c
@@ -100,11 +100,15 @@ struct bus_dmamap {
 static MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
 
 #define	dmat_alignment(dmat)	((dmat)->alignment)
+#define	dmat_bounce_flags(dmat)	(0)
+#define	dmat_boundary(dmat)	((dmat)->boundary)
 #define	dmat_flags(dmat)	((dmat)->flags)
 #define	dmat_highaddr(dmat)	((dmat)->highaddr)
 #define	dmat_lowaddr(dmat)	((dmat)->lowaddr)
 #define	dmat_lockfunc(dmat)	((dmat)->lockfunc)
 #define	dmat_lockfuncarg(dmat)	((dmat)->lockfuncarg)
+#define	dmat_maxsegsz(dmat)	((dmat)->maxsegsz)
+#define	dmat_nsegments(dmat)	((dmat)->nsegments)
 
 #include "../../kern/subr_busdma_bounce.c"
 
@@ -535,47 +539,6 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 	}
 }
 
-/*
- * Add a single contiguous physical range to the segment list.
- */
-static int
-_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
-		   bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
-{
-	int seg;
-
-	/*
-	 * Make sure we don't cross any boundaries.
-	 */
-	if (!vm_addr_bound_ok(curaddr, sgsize, dmat->boundary))
-		sgsize = roundup2(curaddr, dmat->boundary) - curaddr;
-
-	/*
-	 * Insert chunk into a segment, coalescing with
-	 * previous segment if possible.
-	 */
-	seg = *segp;
-	if (seg == -1) {
-		seg = 0;
-		segs[seg].ds_addr = curaddr;
-		segs[seg].ds_len = sgsize;
-	} else {
-		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
-		    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
-		    vm_addr_bound_ok(segs[seg].ds_addr,
-		    segs[seg].ds_len + sgsize, dmat->boundary))
-			segs[seg].ds_len += sgsize;
-		else {
-			if (++seg >= dmat->nsegments)
-				return (0);
-			segs[seg].ds_addr = curaddr;
-			segs[seg].ds_len = sgsize;
-		}
-	}
-	*segp = seg;
-	return (sgsize);
-}
-
 /*
  * Utility function to load a physical buffer.  segp contains
  * the starting segment on entrace, and the ending segment on exit.
diff --git a/sys/riscv/riscv/busdma_bounce.c b/sys/riscv/riscv/busdma_bounce.c
index e504b122ebd1..cb0d7ea29ecd 100644
--- a/sys/riscv/riscv/busdma_bounce.c
+++ b/sys/riscv/riscv/busdma_bounce.c
@@ -111,11 +111,15 @@ static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 static MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
 
 #define	dmat_alignment(dmat)	((dmat)->common.alignment)
+#define	dmat_bounce_flags(dmat)	((dmat)->bounce_flags)
+#define	dmat_boundary(dmat)	((dmat)->common.boundary)
 #define	dmat_flags(dmat)	((dmat)->common.flags)
 #define	dmat_highaddr(dmat)	((dmat)->common.highaddr)
 #define	dmat_lowaddr(dmat)	((dmat)->common.lowaddr)
 #define	dmat_lockfunc(dmat)	((dmat)->common.lockfunc)
 #define	dmat_lockfuncarg(dmat)	((dmat)->common.lockfuncarg)
+#define	dmat_maxsegsz(dmat)	((dmat)->common.maxsegsz)
+#define	dmat_nsegments(dmat)	((dmat)->common.nsegments)
 
 #include "../../kern/subr_busdma_bounce.c"
 
@@ -547,47 +551,6 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 	}
 }
 
-/*
- * Add a single contiguous physical range to the segment list.
- */
-static bus_size_t
-_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
-    bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
-{
-	int seg;
-
-	/*
-	 * Make sure we don't cross any boundaries.
-	 */
-	if (!vm_addr_bound_ok(curaddr, sgsize, dmat->common.boundary))
-		sgsize = roundup2(curaddr, dmat->common.boundary) - curaddr;
-
-	/*
-	 * Insert chunk into a segment, coalescing with
-	 * previous segment if possible.
-	 */
-	seg = *segp;
-	if (seg == -1) {
-		seg = 0;
-		segs[seg].ds_addr = curaddr;
-		segs[seg].ds_len = sgsize;
-	} else {
-		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
-		    (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
-		    vm_addr_bound_ok(segs[seg].ds_addr,
-		    segs[seg].ds_len + sgsize, dmat->common.boundary))
-			segs[seg].ds_len += sgsize;
-		else {
-			if (++seg >= dmat->common.nsegments)
-				return (0);
-			segs[seg].ds_addr = curaddr;
-			segs[seg].ds_len = sgsize;
-		}
-	}
-	*segp = seg;
-	return (sgsize);
-}
-
 /*
  * Utility function to load a physical buffer.  segp contains
  * the starting segment on entrace, and the ending segment on exit.
diff --git a/sys/x86/x86/busdma_bounce.c b/sys/x86/x86/busdma_bounce.c
index ef96f5ba7bdc..07fbfd6dffcb 100644
--- a/sys/x86/x86/busdma_bounce.c
+++ b/sys/x86/x86/busdma_bounce.c
@@ -108,12 +108,16 @@ static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 static MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
 
 #define	dmat_alignment(dmat)	((dmat)->common.alignment)
+#define	dmat_bounce_flags(dmat)	((dmat)->bounce_flags)
+#define	dmat_boundary(dmat)	((dmat)->common.boundary)
 #define	dmat_domain(dmat)	((dmat)->common.domain)
 #define	dmat_flags(dmat)	((dmat)->common.flags)
 #define	dmat_highaddr(dmat)	((dmat)->common.highaddr)
 #define	dmat_lowaddr(dmat)	((dmat)->common.lowaddr)
 #define	dmat_lockfunc(dmat)	((dmat)->common.lockfunc)
 #define	dmat_lockfuncarg(dmat)	((dmat)->common.lockfuncarg)
+#define	dmat_maxsegsz(dmat)	((dmat)->common.maxsegsz)
+#define	dmat_nsegments(dmat)	((dmat)->common.nsegments)
 
 #include "../../kern/subr_busdma_bounce.c"
 
@@ -622,54 +626,6 @@ _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 	}
 }
 
-/*
- * Add a single contiguous physical range to the segment list.
- */
-static bus_size_t
-_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
-    bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
-{
-	int seg;
-
-	KASSERT(curaddr <= BUS_SPACE_MAXADDR,
-	    ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
-	    "hi %#jx",
-	    (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
-	    dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
-	    (uintmax_t)dmat->common.highaddr));
-
-	/*
-	 * Make sure we don't cross any boundaries.
-	 */
-	if (!vm_addr_bound_ok(curaddr, sgsize, dmat->common.boundary))
-		sgsize = roundup2(curaddr, dmat->common.boundary) - curaddr;
-
-	/*
-	 * Insert chunk into a segment, coalescing with
-	 * previous segment if possible.
-	 */
-	seg = *segp;
-	if (seg == -1) {
-		seg = 0;
-		segs[seg].ds_addr = curaddr;
-		segs[seg].ds_len = sgsize;
-	} else {
-		if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
-		    (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
-		    vm_addr_bound_ok(segs[seg].ds_addr,
-		    segs[seg].ds_len + sgsize, dmat->common.boundary))
-			segs[seg].ds_len += sgsize;
-		else {
-			if (++seg >= dmat->common.nsegments)
-				return (0);
-			segs[seg].ds_addr = curaddr;
-			segs[seg].ds_len = sgsize;
-		}
-	}
-	*segp = seg;
-	return (sgsize);
-}
-
 /*
  * Utility function to load a physical buffer.  segp contains
  * the starting segment on entrace, and the ending segment on exit.