Index: alpha/alpha/busdma_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/alpha/alpha/busdma_machdep.c,v
retrieving revision 1.28
diff -u -r1.28 busdma_machdep.c
--- alpha/alpha/busdma_machdep.c	4 Feb 2003 16:30:26 -0000	1.28
+++ alpha/alpha/busdma_machdep.c	16 Feb 2003 07:36:30 -0000
@@ -425,11 +425,8 @@
 {
 	vm_offset_t		vaddr;
 	vm_offset_t		paddr;
-#ifdef __GNUC__
-	bus_dma_segment_t	dm_segments[dmat->nsegments];
-#else
-	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
 	bus_dma_segment_t      *sg;
 	int			seg;
 	int			error;
@@ -444,16 +441,16 @@
 		 * of the bus address space.
 		 */
 		vaddr = trunc_page((vm_offset_t) buf);
-		dm_segments[0].ds_addr =
+		stack_dm_segments[0].ds_addr =
 			map->busaddress + (vm_offset_t) buf - vaddr;
-		dm_segments[0].ds_len = buflen;
+		stack_dm_segments[0].ds_len = buflen;
 		buflen = round_page((vm_offset_t) buf + buflen) - vaddr;
 		sgmap_load_region(chipset.sgmap,
 				  map->busaddress,
 				  vaddr,
 				  buflen);
 		map->buflen = buflen;
-		(*callback)(callback_arg, dm_segments, 1, error);
+		(*callback)(callback_arg, stack_dm_segments, 1, error);
 
 		return (0);
 	}
@@ -504,6 +501,14 @@
 		splx(s);
 	}
 
+	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
 	vaddr = (vm_offset_t)buf;
 	sg = &dm_segments[0];
 	seg = 1;
@@ -526,7 +531,8 @@
 		if (sg->ds_len == 0) {
 			sg->ds_addr = paddr + alpha_XXX_dmamap_or;
 			sg->ds_len = size;
-		} else if (paddr == nextpaddr) {
+		} else if (paddr == nextpaddr && 
+		    sg->ds_len + size < dmat->maxsegsz) {
 			sg->ds_len += size;
 		} else {
 			/* Go to the next segment */
@@ -550,6 +556,9 @@
 	}
 
 	(*callback)(callback_arg, dm_segments, seg, error);
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
 
 	return (0);
 }
Index: i386/i386/busdma_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/i386/busdma_machdep.c,v
retrieving revision 1.32
diff -u -r1.32 busdma_machdep.c
--- i386/i386/busdma_machdep.c	4 Feb 2003 16:30:27 -0000	1.32
+++ i386/i386/busdma_machdep.c	16 Feb 2003 02:21:08 -0000
@@ -403,11 +403,8 @@
 {
 	vm_offset_t		vaddr;
 	vm_offset_t		paddr;
-#ifdef __GNUC__
-	bus_dma_segment_t	dm_segments[dmat->nsegments];
-#else
-	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
 	bus_dma_segment_t      *sg;
 	int			seg;
 	int			error;
@@ -463,6 +460,14 @@
 		splx(s);
 	}
 
+	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
 	vaddr = (vm_offset_t)buf;
 	sg = &dm_segments[0];
 	seg = 1;
@@ -484,7 +489,8 @@
 		if (sg->ds_len == 0) {
 			sg->ds_addr = paddr;
 			sg->ds_len = size;
-		} else if (paddr == nextpaddr) {
+		} else if (paddr == nextpaddr && 
+		    sg->ds_len + size < dmat->maxsegsz) {
 			sg->ds_len += size;
 		} else {
 			/* Go to the next segment */
@@ -508,6 +514,9 @@
 	}
 
 	(*callback)(callback_arg, dm_segments, seg, error);
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
 
 	return (0);
 }
Index: ia64/ia64/busdma_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/ia64/ia64/busdma_machdep.c,v
retrieving revision 1.14
diff -u -r1.14 busdma_machdep.c
--- ia64/ia64/busdma_machdep.c	4 Feb 2003 16:30:27 -0000	1.14
+++ ia64/ia64/busdma_machdep.c	16 Feb 2003 18:36:58 -0000
@@ -393,11 +393,8 @@
 {
 	vm_offset_t		vaddr;
 	vm_offset_t		paddr;
-#ifdef __GNUC__
-	bus_dma_segment_t	dm_segments[dmat->nsegments];
-#else
-	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
 	bus_dma_segment_t      *sg;
 	int			seg;
 	int			error;
@@ -412,9 +409,9 @@
 		 * of the bus address space.
 		 */
 		vaddr = trunc_page((vm_offset_t) buf);
-		dm_segments[0].ds_addr =
+		stack_dm_segments[0].ds_addr =
 			map->busaddress + (vm_offset_t) buf - vaddr;
-		dm_segments[0].ds_len = buflen;
+		stack_dm_segments[0].ds_len = buflen;
 		buflen = round_page((vm_offset_t) buf + buflen) - vaddr;
 #if 0
 		sgmap_load_region(chipset.sgmap,
@@ -423,7 +420,7 @@
 				  buflen);
 #endif
 		map->buflen = buflen;
-		(*callback)(callback_arg, dm_segments, 1, error);
+		(*callback)(callback_arg, stack_dm_segments, 1, error);
 
 		return (0);
 	}
@@ -474,6 +471,14 @@
 		splx(s);
 	}
 
+	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
 	vaddr = (vm_offset_t)buf;
 	sg = &dm_segments[0];
 	seg = 1;
@@ -496,7 +501,8 @@
 		if (sg->ds_len == 0) {
 			sg->ds_addr = paddr;
 			sg->ds_len = size;
-		} else if (paddr == nextpaddr) {
+		} else if (paddr == nextpaddr && 
+		    sg->ds_len + size < dmat->maxsegsz) {
 			sg->ds_len += size;
 		} else {
 			/* Go to the next segment */
@@ -520,6 +526,9 @@
 	}
 
 	(*callback)(callback_arg, dm_segments, seg, error);
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
 
 	return (0);
 }
Index: powerpc/powerpc/busdma_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/powerpc/powerpc/busdma_machdep.c,v
retrieving revision 1.7
diff -u -r1.7 busdma_machdep.c
--- powerpc/powerpc/busdma_machdep.c	4 Feb 2003 16:30:26 -0000	1.7
+++ powerpc/powerpc/busdma_machdep.c	16 Feb 2003 18:36:04 -0000
@@ -254,11 +254,8 @@
 {
         vm_offset_t             vaddr;
         vm_offset_t             paddr;
-#ifdef __GNUC__
-        bus_dma_segment_t       dm_segments[dmat->nsegments];
-#else
-        bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
         bus_dma_segment_t      *sg;
         int                     seg;
         int                     error = 0;
@@ -267,7 +264,15 @@
         if (map != NULL)
 		panic("bus_dmamap_load: Invalid map\n");
 
-        vaddr = (vm_offset_t)buf;
+ 	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
+	vaddr = (vm_offset_t)buf;
         sg = &dm_segments[0];
         seg = 1;
         sg->ds_len = 0;
@@ -284,7 +289,8 @@
                 if (sg->ds_len == 0) {
                         sg->ds_addr = paddr;
                         sg->ds_len = size;
-                } else if (paddr == nextpaddr) {
+                } else if (paddr == nextpaddr && 
+		    sg->ds_len + size < dmat->maxsegsz) {
                         sg->ds_len += size;
                 } else {
                         /* Go to the next segment */
@@ -308,7 +314,10 @@
 	}
 
 	(*callback)(callback_arg, dm_segments, seg, error);
-	
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
+
 	return (0);
 }
 
Index: sparc64/sparc64/bus_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/sparc64/bus_machdep.c,v
retrieving revision 1.19
diff -u -r1.19 bus_machdep.c
--- sparc64/sparc64/bus_machdep.c	4 Feb 2003 16:30:27 -0000	1.19
+++ sparc64/sparc64/bus_machdep.c	16 Feb 2003 18:33:06 -0000
@@ -408,14 +408,19 @@
     void *buf, bus_size_t buflen, bus_dmamap_callback_t *callback,
     void *callback_arg, int flags)
 {
-#ifdef __GNUC__
-	bus_dma_segment_t dm_segments[ddmat->dt_nsegments];
-#else
-	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
 	vm_offset_t lastaddr;
 	int error, nsegs;
 
+ 	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
 	error = _nexus_dmamap_load_buffer(ddmat, dm_segments, buf, buflen,
 	    NULL, flags, &lastaddr, &nsegs, 1);
 
@@ -424,6 +429,9 @@
 		map->dm_loaded = 1;
 	} else
 		(*callback)(callback_arg, NULL, 0, error);
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
 
 	return (0);
 }