From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
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 <john.fastabend@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Cc: Anatoly Burakov <anatoly.burakov@xxxxxxxxx>
Cc: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
Cc: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
Cc: Maryam Tahhan <mtahhan@xxxxxxxxxx>
Cc: xdp-hints@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
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 f787c3f524b0..3e952e569418 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;
--
2.38.1.584.g0f3c55d4c2-goog
