[RFC PATCH 10/24] netdevice: added XDP_{UN,}REGISTER_XSK command to ndo_bpf

[Björn Töpel]

From: Magnus Karlsson <magnus.karls...@intel.com>

Here, ndo_bpf is extended with two sub-commands: XDP_REGISTER_XSK and
XDP_UNREGISTER_XSK. They are used to support zero copy allocators with
XDP sockets.

Signed-off-by: Magnus Karlsson <magnus.karls...@intel.com>
---
 include/linux/netdevice.h | 17 +++++++++++++++++
 include/net/xdp_sock.h    | 30 +++++++++++++++++++++++++++++-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 36cc7e92bd8e..a997649dd5cc 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -810,10 +810,18 @@ enum bpf_netdev_command {
        BPF_OFFLOAD_DESTROY,
        BPF_OFFLOAD_MAP_ALLOC,
        BPF_OFFLOAD_MAP_FREE,
+       /* Registers callbacks with the driver that is used to support
+        * AF_XDP sockets in zero copy mode.
+        */
+       XDP_REGISTER_XSK,
+       /* Unregisters and AF_XDP socket in zero copy mode. */
+       XDP_UNREGISTER_XSK,
 };
 
 struct bpf_prog_offload_ops;
 struct netlink_ext_ack;
+struct xsk_tx_parms;
+struct xsk_rx_parms;
 
 struct netdev_bpf {
        enum bpf_netdev_command command;
@@ -844,6 +852,15 @@ struct netdev_bpf {
                struct {
                        struct bpf_offloaded_map *offmap;
                };
+               /* XDP_REGISTER_XSK, XDP_UNREGISTER_XSK
+                * All fields used for XDP_REGISTER_XSK.
+                * queue_id the only field used for XDP_UNREGISTER_XSK.
+                */
+               struct {
+                       struct xsk_tx_parms *tx_parms;
+                       struct xsk_rx_parms *rx_parms;
+                       u32 queue_id;
+               } xsk;
        };
 };
 
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index 132489fe0e70..866ea7191217 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -1,8 +1,36 @@
 #ifndef _LINUX_AF_XDP_SOCK_H
 #define _LINUX_AF_XDP_SOCK_H
 
-struct xdp_sock;
+#include <linux/dma-direction.h>
+
+struct buff_pool;
+struct net_device;
 struct xdp_buff;
+struct xdp_sock;
+
+/* These two functions have to be called from the same serializing conext,
+ * for example the same NAPI context.
+ * They should not be called for the XDP_SKB path, only XDP_DRV.
+ */
+
+struct xsk_tx_parms {
+       void (*tx_completion)(u32 start, u32 npackets,
+                             unsigned long ctx1, unsigned long ctx2);
+       unsigned long ctx1;
+       unsigned long ctx2;
+       int (*get_tx_packet)(struct net_device *dev, u32 queue_id,
+                            dma_addr_t *dma, void **data, u32 *len,
+                            u32 *offset);
+};
+
+struct xsk_rx_parms {
+       struct buff_pool *buff_pool;
+       int (*dma_map)(struct buff_pool *bp, struct device *dev,
+                      enum dma_data_direction dir,
+                      unsigned long attr);
+       void *error_report_ctx;
+       void (*error_report)(void *ctx, int errno);
+};
 
 #ifdef CONFIG_XDP_SOCKETS
 int xsk_generic_rcv(struct xdp_buff *xdp);
-- 
2.14.1