Re: [PATCH 4/5] net: page_pool: refactor dma_map into own function page_pool_dma_map

On Wed, 3 Mar 2021 09:18:25 +0000
Mel Gorman [off-list ref] wrote:

On Tue, Mar 02, 2021 at 08:49:06PM +0200, Ilias Apalodimas wrote:

quoted

On Mon, Mar 01, 2021 at 04:11:59PM +0000, Mel Gorman wrote:  

quoted

From: Jesper Dangaard Brouer <redacted>

In preparation for next patch, move the dma mapping into its own
function, as this will make it easier to follow the changes.

V2: make page_pool_dma_map return boolean (Ilias)
  

[...]
  

quoted

@@ -211,30 +234,14 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
 	if (!page)
 		return NULL;
 
-	if (!(pool->p.flags & PP_FLAG_DMA_MAP))
-		goto skip_dma_map;
-
-	/* Setup DMA mapping: use 'struct page' area for storing DMA-addr
-	 * since dma_addr_t can be either 32 or 64 bits and does not always fit
-	 * into page private data (i.e 32bit cpu with 64bit DMA caps)
-	 * This mapping is kept for lifetime of page, until leaving pool.
-	 */
-	dma = dma_map_page_attrs(pool->p.dev, page, 0,
-				 (PAGE_SIZE << pool->p.order),
-				 pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (dma_mapping_error(pool->p.dev, dma)) {
+	if (pp_flags & PP_FLAG_DMA_MAP &&  

Nit pick but can we have if ((pp_flags & PP_FLAG_DMA_MAP) && ...
  

Done.

Thanks for fixing this nitpick, and carrying the patch.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer