net: page_pool: API cleanup and comments

Functions starting with __ usually indicate those which are exported,
but should not be called directly. Update some of those declared in the
API and make it more readable.

page_pool_unmap_page() and page_pool_release_page() were doing
exactly the same thing calling __page_pool_clean_page().  Let's
rename __page_pool_clean_page() to page_pool_release_page() and
export it in order to show up on perf logs and get rid of
page_pool_unmap_page().

Finally rename __page_pool_put_page() to page_pool_put_page() since we
can now directly call it from drivers and rename the existing
page_pool_put_page() to page_pool_put_full_page() since they do the same
thing but the latter is trying to sync the full DMA area.

This patch also updates netsec, mvneta and stmmac drivers which use
those functions.

Suggested-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 22 deletions

diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index cfbed00ba7ee..81d7773f96cd 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -151,6 +151,7 @@ struct page_pool *page_pool_create(const struct page_pool_params *params);
 #ifdef CONFIG_PAGE_POOL
 void page_pool_destroy(struct page_pool *pool);
 void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *));
+void page_pool_release_page(struct page_pool *pool, struct page *page);
 #else
 static inline void page_pool_destroy(struct page_pool *pool)
 {
@@ -160,41 +161,32 @@ static inline void page_pool_use_xdp_mem(struct page_pool *pool,
 					 void (*disconnect)(void *))
 {
 }
+static inline void page_pool_release_page(struct page_pool *pool,
+					  struct page *page)
+{
+}
 #endif
 
-/* Never call this directly, use helpers below */
-void __page_pool_put_page(struct page_pool *pool, struct page *page,
-			  unsigned int dma_sync_size, bool allow_direct);
+void page_pool_put_page(struct page_pool *pool, struct page *page,
+			unsigned int dma_sync_size, bool allow_direct);
 
-static inline void page_pool_put_page(struct page_pool *pool,
-				      struct page *page, bool allow_direct)
+/* Same as above but will try to sync the entire area pool->max_len */
+static inline void page_pool_put_full_page(struct page_pool *pool,
+					   struct page *page, bool allow_direct)
 {
 	/* When page_pool isn't compiled-in, net/core/xdp.c doesn't
 	 * allow registering MEM_TYPE_PAGE_POOL, but shield linker.
 	 */
 #ifdef CONFIG_PAGE_POOL
-	__page_pool_put_page(pool, page, -1, allow_direct);
+	page_pool_put_page(pool, page, -1, allow_direct);
 #endif
 }
-/* Very limited use-cases allow recycle direct */
+
+/* Same as above but the caller must guarantee safe context. e.g NAPI */
 static inline void page_pool_recycle_direct(struct page_pool *pool,
 					    struct page *page)
 {
-	__page_pool_put_page(pool, page, -1, true);
-}
-
-/* Disconnects a page (from a page_pool).  API users can have a need
- * to disconnect a page (from a page_pool), to allow it to be used as
- * a regular page (that will eventually be returned to the normal
- * page-allocator via put_page).
- */
-void page_pool_unmap_page(struct page_pool *pool, struct page *page);
-static inline void page_pool_release_page(struct page_pool *pool,
-					  struct page *page)
-{
-#ifdef CONFIG_PAGE_POOL
-	page_pool_unmap_page(pool, page);
-#endif
+	page_pool_put_full_page(pool, page, true);
 }
 
 static inline dma_addr_t page_pool_get_dma_addr(struct page *page)