Index: head/sys/x86/x86/busdma_bounce.c
===================================================================
--- head/sys/x86/x86/busdma_bounce.c
+++ head/sys/x86/x86/busdma_bounce.c
@@ -476,8 +476,7 @@
 		while (buflen != 0) {
 			sgsize = MIN(buflen, dmat->common.maxsegsz);
 			if (bus_dma_run_filter(&dmat->common, curaddr)) {
-				sgsize = MIN(sgsize,
-				    PAGE_SIZE - (curaddr & PAGE_MASK));
+				sgsize = MIN(PAGE_SIZE, sgsize);
 				map->pagesneeded++;
 			}
 			curaddr += sgsize;
@@ -517,8 +516,7 @@
 			else
 				paddr = pmap_extract(pmap, vaddr);
 			if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
-				sg_len = roundup2(sg_len,
-				    dmat->common.alignment);
+				sg_len = PAGE_SIZE;
 				map->pagesneeded++;
 			}
 			vaddr += sg_len;
@@ -554,9 +552,7 @@
 			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 = roundup2(sg_len,
-				    dmat->common.alignment);
-				sg_len = MIN(sg_len, max_sgsize);
+				sg_len = MIN(PAGE_SIZE, max_sgsize);
 				KASSERT((sg_len & (dmat->common.alignment - 1))
 				    == 0, ("Segment size is not aligned"));
 				map->pagesneeded++;
@@ -652,7 +648,7 @@
     int *segp)
 {
 	bus_size_t sgsize;
-	bus_addr_t curaddr;
+	bus_addr_t curaddr, nextaddr;
 	int error;
 
 	if (map == NULL)
@@ -676,9 +672,12 @@
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, curaddr)) {
-			sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
-			curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
-			    sgsize);
+			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 = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 		    segp);
@@ -744,8 +743,7 @@
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, curaddr)) {
-			sgsize = roundup2(sgsize, dmat->common.alignment);
-			sgsize = MIN(sgsize, max_sgsize);
+			sgsize = MIN(PAGE_SIZE, max_sgsize);
 			curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 			    sgsize);
 		} else {
@@ -774,17 +772,6 @@
 	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;
 
@@ -811,10 +798,7 @@
 		if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 		    map->pagesneeded != 0 &&
 		    bus_dma_run_filter(&dmat->common, paddr)) {
-			sgsize = roundup2(sgsize, dmat->common.alignment);
-			sgsize = MIN(sgsize, max_sgsize);
-			KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
-			    ("Segment size is not aligned"));
+			sgsize = MIN(PAGE_SIZE, max_sgsize);
 			/*
 			 * Check if two pages of the user provided buffer
 			 * are used.
@@ -1175,13 +1159,6 @@
 	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"));
@@ -1201,15 +1178,6 @@
 	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);