From 94ecc5ca4dbf1f01bae6e32f5cd88c0fc5dc3cc9 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Thu, 19 Jan 2023 14:15:33 -0800 Subject: [PATCH] xsk: Add cb area to struct xdp_buff_xsk MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add an area after the xdp_buff in struct xdp_buff_xsk that drivers can use to stash extra information to use in metadata kfuncs. The maximum size of 24 bytes means the full xdp_buff_xsk structure will take up exactly two cache lines (with the cb field spanning both). Also add a macro drivers can use to check their own wrapping structs against the available size. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Jakub Kicinski Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Suggested-by: Jakub Kicinski Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230119221536.3349901-15-sdf@google.com Signed-off-by: Martin KaFai Lau --- include/net/xsk_buff_pool.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h index f787c3f524b03..3e952e5694188 100644 --- a/include/net/xsk_buff_pool.h +++ b/include/net/xsk_buff_pool.h @@ -19,8 +19,11 @@ struct xdp_sock; struct device; struct page; +#define XSK_PRIV_MAX 24 + struct xdp_buff_xsk { struct xdp_buff xdp; + u8 cb[XSK_PRIV_MAX]; dma_addr_t dma; dma_addr_t frame_dma; struct xsk_buff_pool *pool; @@ -28,6 +31,8 @@ struct xdp_buff_xsk { struct list_head free_list_node; }; +#define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb)) + struct xsk_dma_map { dma_addr_t *dma_pages; struct device *dev; -- 2.49.0