static int
 check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
 {
-       if (hwdev && bus + size > *hwdev->dma_mask) {
+       if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
                if (*hwdev->dma_mask >= DMA_32BIT_MASK)
                        printk(KERN_ERR
                            "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
        unsigned long dma_mask;
        int node;
        struct page *page;
+       dma_addr_t addr;
 
        dma_mask = dma_alloc_coherent_mask(hwdev, gfp);
 
        if (!page)
                return NULL;
 
-       if ((page_to_phys(page) + size > dma_mask) && !(gfp & GFP_DMA)) {
+       addr = page_to_phys(page);
+       if (!is_buffer_dma_capable(dma_mask, addr, size) && !(gfp & GFP_DMA)) {
                free_pages((unsigned long)page_address(page), get_order(size));
                gfp |= GFP_DMA;
                goto again;
        }
 
-       *dma_addr = page_to_phys(page);
-       if (check_addr("alloc_coherent", hwdev, *dma_addr, size)) {
+       if (check_addr("alloc_coherent", hwdev, addr, size)) {
+               *dma_addr = addr;
                flush_write_buffers();
                return page_address(page);
        }