use direct_map above, it now must be considered an error. */
        if (! alpha_mv.mv_pci_tbi) {
                printk_once(KERN_WARNING "pci_map_single: no HW sg\n");
-               return 0;
+               return DMA_MAPPING_ERROR;
        }
 
        arena = hose->sg_pci;
        if (dma_ofs < 0) {
                printk(KERN_WARNING "pci_map_single failed: "
                       "could not allocate dma page tables\n");
-               return 0;
+               return DMA_MAPPING_ERROR;
        }
 
        paddr &= PAGE_MASK;
        memset(cpu_addr, 0, size);
 
        *dma_addrp = pci_map_single_1(pdev, cpu_addr, size, 0);
-       if (*dma_addrp == 0) {
+       if (*dma_addrp == DMA_MAPPING_ERROR) {
                free_pages((unsigned long)cpu_addr, order);
                if (alpha_mv.mv_pci_tbi || (gfp & GFP_DMA))
                        return NULL;
                sg->dma_address
                  = pci_map_single_1(pdev, SG_ENT_VIRT_ADDRESS(sg),
                                     sg->length, dac_allowed);
-               return sg->dma_address != 0;
+               return sg->dma_address != DMA_MAPPING_ERROR;
        }
 
        start = sg;
        return 0;
 }
 
-static int alpha_pci_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
-       return dma_addr == 0;
-}
-
 const struct dma_map_ops alpha_pci_ops = {
        .alloc                  = alpha_pci_alloc_coherent,
        .free                   = alpha_pci_free_coherent,
        .unmap_page             = alpha_pci_unmap_page,
        .map_sg                 = alpha_pci_map_sg,
        .unmap_sg               = alpha_pci_unmap_sg,
-       .mapping_error          = alpha_pci_mapping_error,
        .dma_supported          = alpha_pci_supported,
 };
 EXPORT_SYMBOL(alpha_pci_ops);