[RFC v4 05/18] page_pool: use netmem alloc/put APIs in __page_pool_alloc_pages_slow()

[Byungchul Park]

Use netmem alloc/put APIs instead of page alloc/put APIs in
__page_pool_alloc_pages_slow().

While at it, improved some comments.

Signed-off-by: Byungchul Park <byungchul@xxxxxx>
Reviewed-by: Mina Almasry <almasrymina@xxxxxxxxxx>
---
 net/core/page_pool.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index ff3d0d31263c..e80a637f0fa4 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -551,7 +551,7 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
 	unsigned int pp_order = pool->p.order;
 	bool dma_map = pool->dma_map;
 	netmem_ref netmem;
-	int i, nr_pages;
+	int i, nr_netmems;
 
 	/* Don't support bulk alloc for high-order pages */
 	if (unlikely(pp_order))
@@ -561,21 +561,21 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
 	if (unlikely(pool->alloc.count > 0))
 		return pool->alloc.cache[--pool->alloc.count];
 
-	/* Mark empty alloc.cache slots "empty" for alloc_pages_bulk */
+	/* Mark empty alloc.cache slots "empty" for alloc_netmems_bulk_node() */
 	memset(&pool->alloc.cache, 0, sizeof(void *) * bulk);
 
-	nr_pages = alloc_pages_bulk_node(gfp, pool->p.nid, bulk,
-					 (struct page **)pool->alloc.cache);
-	if (unlikely(!nr_pages))
+	nr_netmems = alloc_netmems_bulk_node(gfp, pool->p.nid, bulk,
+					     pool->alloc.cache);
+	if (unlikely(!nr_netmems))
 		return 0;
 
-	/* Pages have been filled into alloc.cache array, but count is zero and
-	 * page element have not been (possibly) DMA mapped.
+	/* Netmems have been filled into alloc.cache array, but count is
+	 * zero and elements have not been (possibly) DMA mapped.
 	 */
-	for (i = 0; i < nr_pages; i++) {
+	for (i = 0; i < nr_netmems; i++) {
 		netmem = pool->alloc.cache[i];
 		if (dma_map && unlikely(!page_pool_dma_map(pool, netmem, gfp))) {
-			put_page(netmem_to_page(netmem));
+			put_netmem(netmem);
 			continue;
 		}
 
@@ -587,7 +587,7 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
 					   pool->pages_state_hold_cnt);
 	}
 
-	/* Return last page */
+	/* Return the last netmem */
 	if (likely(pool->alloc.count > 0)) {
 		netmem = pool->alloc.cache[--pool->alloc.count];
 		alloc_stat_inc(pool, slow);
@@ -595,7 +595,9 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
 		netmem = 0;
 	}
 
-	/* When page just alloc'ed is should/must have refcnt 1. */
+	/* When a netmem has been just allocated, it should/must have
+	 * refcnt 1.
+	 */
 	return netmem;
 }
 
-- 
2.17.1