Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index 694d055..2cbcdbd 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h
@@ -16,14 +16,16 @@
* page_pool_alloc_pages() call. Drivers should likely use
* page_pool_dev_alloc_pages() replacing dev_alloc_pages().
*
- * If page_pool handles DMA mapping (use page->private), then API user
- * is responsible for invoking page_pool_put_page() once. In-case of
- * elevated refcnt, the DMA state is released, assuming other users of
- * the page will eventually call put_page().
+ * API keeps track of in-flight pages, in-order to let API user know
+ * when it is safe to dealloactor page_pool object. Thus, API users
+ * must make sure to call page_pool_release_page() when a page is
+ * "leaving" the page_pool. Or call page_pool_put_page() where
+ * appropiate. For maintaining correct accounting.
*
- * If no DMA mapping is done, then it can act as shim-layer that
- * fall-through to alloc_page. As no state is kept on the page, the
- * regular put_page() call is sufficient.
+ * API user must only call page_pool_put_page() once on a page, as it
+ * will either recycle the page, or in case of elevated refcnt, it
+ * will release the DMA mapping and in-flight state accounting. We
+ * hope to lift this requirement in the future.
*/
#ifndef _NET_PAGE_POOL_H
#define _NET_PAGE_POOL_H
@@ -66,9 +68,10 @@
};
struct page_pool {
- struct rcu_head rcu;
struct page_pool_params p;
+ u32 pages_state_hold_cnt;
+
/*
* Data structure for allocation side
*
@@ -96,6 +99,14 @@
* TODO: Implement bulk return pages into this structure.
*/
struct ptr_ring ring;
+
+ atomic_t pages_state_release_cnt;
+
+ /* A page_pool is strictly tied to a single RX-queue being
+ * protected by NAPI, due to above pp_alloc_cache. This
+ * refcnt serves purpose is to simplify drivers error handling.
+ */
+ refcount_t user_cnt;
};
struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
@@ -107,9 +118,36 @@
return page_pool_alloc_pages(pool, gfp);
}
+/* get the stored dma direction. A driver might decide to treat this locally and
+ * avoid the extra cache line from page_pool to determine the direction
+ */
+static
+inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
+{
+ return pool->p.dma_dir;
+}
+
struct page_pool *page_pool_create(const struct page_pool_params *params);
-void page_pool_destroy(struct page_pool *pool);
+void __page_pool_free(struct page_pool *pool);
+static inline void page_pool_free(struct page_pool *pool)
+{
+ /* 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_free(pool);
+#endif
+}
+
+/* Drivers use this instead of page_pool_free */
+static inline void page_pool_destroy(struct page_pool *pool)
+{
+ if (!pool)
+ return;
+
+ page_pool_free(pool);
+}
/* Never call this directly, use helpers below */
void __page_pool_put_page(struct page_pool *pool,
@@ -132,6 +170,43 @@
__page_pool_put_page(pool, page, true);
}
+/* API user MUST have disconnected alloc-side (not allowed to call
+ * page_pool_alloc_pages()) before calling this. The free-side can
+ * still run concurrently, to handle in-flight packet-pages.
+ *
+ * A request to shutdown can fail (with false) if there are still
+ * in-flight packet-pages.
+ */
+bool __page_pool_request_shutdown(struct page_pool *pool);
+static inline bool page_pool_request_shutdown(struct page_pool *pool)
+{
+ bool safe_to_remove = false;
+
+#ifdef CONFIG_PAGE_POOL
+ safe_to_remove = __page_pool_request_shutdown(pool);
+#endif
+ return safe_to_remove;
+}
+
+/* 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
+}
+
+static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
+{
+ return page->dma_addr;
+}
+
static inline bool is_page_pool_compiled_in(void)
{
#ifdef CONFIG_PAGE_POOL
@@ -141,4 +216,14 @@
#endif
}
+static inline void page_pool_get(struct page_pool *pool)
+{
+ refcount_inc(&pool->user_cnt);
+}
+
+static inline bool page_pool_put(struct page_pool *pool)
+{
+ return refcount_dec_and_test(&pool->user_cnt);
+}
+
#endif /* _NET_PAGE_POOL_H */