From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Tue, 22 Dec 2020 22:09:29 +0100
Patch-mainline: v5.12-rc1
Subject: net, xdp: Introduce xdp_prepare_buff utility routine
Git-commit: be9df4aff65f18caa79b35f88f42c3d5a43af14f
References: bsc#1193507

Introduce xdp_prepare_buff utility routine to initialize per-descriptor
xdp_buff fields (e.g. xdp_buff pointers). Rely on xdp_prepare_buff() in
all XDP capable drivers.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Acked-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/45f46f12295972a97da8ca01990b3e71501e9d89.1608670965.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Olaf Hering <ohering@suse.de>
---
 include/net/xdp.h                             | 12 +++++++++++
 28 files changed, 105 insertions(+), 152 deletions(-)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 8a589f7e08e0..0cf3976ce77c 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -83,6 +83,18 @@ xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
 	xdp->rxq = rxq;
 }
 
+static __always_inline void
+xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start,
+		 int headroom, int data_len, const bool meta_valid)
+{
+	unsigned char *data = hard_start + headroom;
+
+	xdp->data_hard_start = hard_start;
+	xdp->data = data;
+	xdp->data_end = data + data_len;
+	xdp->data_meta = meta_valid ? data : data + 1;
+}
+
 struct netdev_bpf;
 int xdp_attachment_query(struct xdp_attachment_info *info,
 			 struct netdev_bpf *bpf);