[RFC PATCH v3 09/20] netdev: add XDP_SETUP_ZC_RX command

[David Wei <dw@davidwei.uk>]

From: David Wei <davidhwei@meta.com>

RFC ONLY, NOT FOR UPSTREAM
This will be replaced with a separate ndo callback or some other
mechanism in next patchset revisions.

This patch adds a new XDP_SETUP_ZC_RX command that will be used in a
later patch to enable or disable ZC RX for a specific RX queue.

We are open to suggestions on a better way of doing this. Google's TCP
devmem proposal sets up struct netdev_rx_queue which persists across
device reset, then expects userspace to use an out-of-band method (e.g.
ethtool) to reset the device, thus re-filling a hardware Rx queue.

Signed-off-by: David Wei <dw@davidwei.uk>
---
 include/linux/netdevice.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a4bdc35c7d6f..5b4df0b6a6c0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1097,6 +1097,7 @@ enum bpf_netdev_command {
 	BPF_OFFLOAD_MAP_ALLOC,
 	BPF_OFFLOAD_MAP_FREE,
 	XDP_SETUP_XSK_POOL,
+	XDP_SETUP_ZC_RX,
 };
 
 struct bpf_prog_offload_ops;
@@ -1135,6 +1136,11 @@ struct netdev_bpf {
 			struct xsk_buff_pool *pool;
 			u16 queue_id;
 		} xsk;
+		/* XDP_SETUP_ZC_RX */
+		struct {
+			struct io_zc_rx_ifq *ifq;
+			u16 queue_id;
+		} zc_rx;
 	};
 };
 
-- 
2.39.3