net: xsk: add a simple buffer reuse queue

XSK UMEM is strongly single producer single consumer so reuse of
frames is challenging.  Add a simple "stash" of FILL packets to
reuse for drivers to optionally make use of.  This is useful
when driver has to free (ndo_stop) or resize a ring with an active
AF_XDP ZC socket.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index b3b632c5aeae..555427b3e0fe 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -165,6 +165,8 @@ static void xdp_umem_release(struct xdp_umem *umem)
 		umem->cq = NULL;
 	}
 
+	xsk_reuseq_destroy(umem);
+
 	xdp_umem_unpin_pages(umem);
 
 	task = get_pid_task(umem->pid, PIDTYPE_PID);