xsk: add Tx queue setup and mmap support

Another setsockopt (XDP_TX_QUEUE) is added to let the process allocate
a queue, where the user process can pass frames to be transmitted by
the kernel.

The mmapping of the queue is done using the XDP_PGOFF_TX_QUEUE offset.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index 71581a139f26..e2ea878d025c 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -34,6 +34,7 @@ struct sockaddr_xdp {
 
 /* XDP socket options */
 #define XDP_RX_RING                     1
+#define XDP_TX_RING                     2
 #define XDP_UMEM_REG                    3
 #define XDP_UMEM_FILL_RING              4
 #define XDP_UMEM_COMPLETION_RING        5
@@ -47,6 +48,7 @@ struct xdp_umem_reg {
 
 /* Pgoff for mmaping the rings */
 #define XDP_PGOFF_RX_RING                         0
+#define XDP_PGOFF_TX_RING                0x80000000
 #define XDP_UMEM_PGOFF_FILL_RING        0x100000000
 #define XDP_UMEM_PGOFF_COMPLETION_RING  0x180000000