powerpc: Fix DMA offset for non-coherent DMA

After Becky's work we can almost have different DMA offsets
between on-chip devices and PCI. Almost because there's a
problem with the non-coherent DMA code that basically ignores
the programmed offset to use the global one for everything.
This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/dma.c

@@ -30,11 +30,15 @@ static unsigned long get_dma_direct_offset(struct device *dev)
 void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 				dma_addr_t *dma_handle, gfp_t flag)
 {
+	void *ret;
 #ifdef CONFIG_NOT_COHERENT_CACHE
-	return __dma_alloc_coherent(size, dma_handle, flag);
+	ret = __dma_alloc_coherent(size, dma_handle, flag);
+	if (ret == NULL)
+		return NULL;
+	*dma_handle += get_dma_direct_offset(dev);
+	return ret;
 #else
 	struct page *page;
-	void *ret;
 	int node = dev_to_node(dev);
 
 	/* ignore region specifiers */

arch/powerpc/lib/dma-noncoherent.c

@@ -203,7 +203,7 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
 		/*
 		 * Set the "dma handle"
 		 */
-		*handle = page_to_bus(page);
+		*handle = page_to_phys(page);
 
 		do {
 			BUG_ON(!pte_none(*pte));