diff --git a/sys/x86/x86/busdma_bounce.c b/sys/x86/x86/busdma_bounce.c
index 6e9aa70e5292..78d04b94f0de 100644
--- a/sys/x86/x86/busdma_bounce.c
+++ b/sys/x86/x86/busdma_bounce.c
@@ -476,7 +476,8 @@ _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 		while (buflen != 0) {
 			sgsize = MIN(buflen, dmat->common.maxsegsz);
 			if (bus_dma_run_filter(&dmat->common, curaddr)) {
-				sgsize = MIN(PAGE_SIZE, sgsize);
+				sgsize = MIN(sgsize,
+				    PAGE_SIZE - (curaddr & PAGE_MASK));
 				map->pagesneeded++;
 			}
 			curaddr += sgsize;
@@ -516,7 +517,8 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 			else
 				paddr = pmap_extract(pmap, vaddr);
 			if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
-				sg_len = PAGE_SIZE;
+				sg_len = roundup2(sg_len,
+				    dmat->common.alignment);
 				map->pagesneeded++;
 			}
 			vaddr += sg_len;
@@ -552,7 +554,9 @@ _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 			max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 			sg_len = MIN(sg_len, max_sgsize);
 			if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
-				sg_len = MIN(PAGE_SIZE, max_sgsize);
+				sg_len = roundup2(sg_len,
+				    dmat->common.alignment);
+				sg_len = MIN(sg_len, max_sgsize);
 				KASSERT((sg_len & (dmat->common.alignment - 1))
 				    == 0, ("Segment size is not aligned"));
 				map->pagesneeded++;
@@ -648,7 +652,7 @@ bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
     int *segp)
 {
 	bus_size_t sgsize;
-	bus_addr_t curaddr, nextaddr;
+	bus_addr_t curaddr;
 	int error;
 
 	if (map == NULL)
@@ -672,12 +676,9 @@ bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, curaddr)) {
-			nextaddr = 0;
-			sgsize = MIN(PAGE_SIZE, sgsize);
-			if ((curaddr & PAGE_MASK) + sgsize > PAGE_SIZE)
-				nextaddr = roundup2(curaddr, PAGE_SIZE);
-			curaddr = add_bounce_page(dmat, map, 0, curaddr,
-			    nextaddr, sgsize);
+			sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
+			curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
+			    sgsize);
 		}
 		sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 		    segp);
@@ -743,7 +744,8 @@ bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, curaddr)) {
-			sgsize = MIN(PAGE_SIZE, max_sgsize);
+			sgsize = roundup2(sgsize, dmat->common.alignment);
+			sgsize = MIN(sgsize, max_sgsize);
 			curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 			    sgsize);
 		} else {
@@ -772,6 +774,17 @@ bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 	int error, page_index;
 	bus_size_t sgsize, max_sgsize;
 
+	if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
+		/*
+		 * If we have to keep the offset of each page this function
+		 * is not suitable, switch back to bus_dmamap_load_ma_triv
+		 * which is going to do the right thing in this case.
+		 */
+		error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
+		    flags, segs, segp);
+		return (error);
+	}
+
 	if (map == NULL)
 		map = &nobounce_dmamap;
 
@@ -798,7 +811,10 @@ bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, paddr)) {
-			sgsize = MIN(PAGE_SIZE, max_sgsize);
+			sgsize = roundup2(sgsize, dmat->common.alignment);
+			sgsize = MIN(sgsize, max_sgsize);
+			KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
+			    ("Segment size is not aligned"));
 			/*
 			 * Check if two pages of the user provided buffer
 			 * are used.
@@ -1159,6 +1175,13 @@ add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 	bz->active_bpages++;
 	mtx_unlock(&bounce_lock);
 
+	if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
+		/* Page offset needs to be preserved. */
+		bpage->vaddr |= addr1 & PAGE_MASK;
+		bpage->busaddr |= addr1 & PAGE_MASK;
+		KASSERT(addr2 == 0,
+	("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
+	}
 	bpage->datavaddr = vaddr;
 	bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
 	KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
@@ -1178,6 +1201,15 @@ free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 	bz = dmat->bounce_zone;
 	bpage->datavaddr = 0;
 	bpage->datacount = 0;
+	if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
+		/*
+		 * Reset the bounce page to start at offset 0.  Other uses
+		 * of this bounce page may need to store a full page of
+		 * data and/or assume it starts on a page boundary.
+		 */
+		bpage->vaddr &= ~PAGE_MASK;
+		bpage->busaddr &= ~PAGE_MASK;
+	}
 
 	mtx_lock(&bounce_lock);
 	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);