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Subject: [PATCH bpf v3 2/9] xsk: introduce helper to determine rxq-

quoted

frag_size

rxq->frag_size is basically a step between consecutive strictly
aligned
frames. In ZC mode, chunk size fits exactly, but if chunks are
unaligned, there is no safe way to determine accessible space to grow
tailroom.

Report frag_size to be zero, if chunks are unaligned, chunk_size
otherwise.

Fixes: 24ea50127ecf ("xsk: support mbuf on ZC RX")
Signed-off-by: Larysa Zaremba <redacted>
---
 include/net/xdp_sock_drv.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 242e34f771cc..09d972f4bd60 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h

@@ -51,6 +51,11 @@ static inline u32 xsk_pool_get_rx_frame_size(struct

xsk_buff_pool *pool)
 	return xsk_pool_get_chunk_size(pool) -
xsk_pool_get_headroom(pool);  }

+static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool
*pool)
+{
+	return pool->unaligned ? 0 : xsk_pool_get_chunk_size(pool); }
+
 static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
 					 struct xdp_rxq_info *rxq)
 {

@@ -337,6 +342,11 @@ static inline u32

xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
 	return 0;
 }

+static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool
*pool)
+{
+	return 0;
+}
+
 static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
 					 struct xdp_rxq_info *rxq)
 {
--
2.52.0