Use synchronize_rcu to wait until the XSK wakeup function finishes
before destroying the resources it uses:
1. ixgbe_down already calls synchronize_rcu after setting __IXGBE_DOWN.
2. After switching the XDP program, call synchronize_rcu to let
ixgbe_xsk_async_xmit exit before the XDP program is freed.
3. Changing the number of channels brings the interface down.
4. Disabling UMEM sets __IXGBE_TX_DISABLED before closing hardware
resources and resetting xsk_umem. Check that bit in ixgbe_xsk_async_xmit
to avoid using the XDP ring when it's already destroyed. synchronize_rcu
is called from ixgbe_txrx_ring_disable.
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 6 +++++-
drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 8 ++++++--
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 25c097cd8100..60503318c7e5 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10273,8 +10273,12 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
adapter->xdp_prog);
}
- if (old_prog)
+ if (old_prog) {
+ /* Wait until ndo_xsk_async_xmit completes. */
+ synchronize_rcu();
+
bpf_prog_put(old_prog);
+ }
/* Kick start the NAPI context if there is an AF_XDP socket open
* on that queue id. This so that receiving will start.
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
index d6feaacfbf89..b43be9f14105 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
@@ -709,10 +709,14 @@ int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
if (qid >= adapter->num_xdp_queues)
return -ENXIO;
- if (!adapter->xdp_ring[qid]->xsk_umem)
+ ring = adapter->xdp_ring[qid];
+
+ if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
+ return -ENETDOWN;
+
+ if (!ring->xsk_umem)
return -ENXIO;
- ring = adapter->xdp_ring[qid];
if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
u64 eics = BIT_ULL(ring->q_vector->v_idx);
--
2.20.1
