Use synchronize_rcu to wait until the XSK wakeup function finishes
before destroying the resources it uses:
1. i40e_down already calls synchronize_rcu. On i40e_down either
__I40E_VSI_DOWN or __I40E_CONFIG_BUSY is set. Check the latter in
i40e_xsk_async_xmit (the former is already checked there).
2. After switching the XDP program, call synchronize_rcu to let
i40e_xsk_async_xmit exit before the XDP program is freed.
3. Changing the number of channels brings the interface down (see
i40e_prep_for_reset and i40e_pf_quiesce_all_vsi).
4. Disabling UMEM sets __I40E_CONFIG_BUSY, too.
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 7 +++++--
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 ++++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 1ccabeafa44c..afa3a99e68e1 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6823,8 +6823,8 @@ void i40e_down(struct i40e_vsi *vsi)
for (i = 0; i < vsi->num_queue_pairs; i++) {
i40e_clean_tx_ring(vsi->tx_rings[i]);
if (i40e_enabled_xdp_vsi(vsi)) {
- /* Make sure that in-progress ndo_xdp_xmit
- * calls are completed.
+ /* Make sure that in-progress ndo_xdp_xmit and
+ * ndo_xsk_async_xmit calls are completed.
*/
synchronize_rcu();
i40e_clean_tx_ring(vsi->xdp_rings[i]);
@@ -12545,6 +12545,9 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi,
i40e_prep_for_reset(pf, true);
old_prog = xchg(&vsi->xdp_prog, prog);
+ if (old_prog)
+ /* Wait until ndo_xsk_async_xmit completes. */
+ synchronize_rcu();
if (need_reset)
i40e_reset_and_rebuild(pf, true, true);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index d07e1a890428..f73cd917c44f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -787,8 +787,12 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
{
struct i40e_netdev_priv *np = netdev_priv(dev);
struct i40e_vsi *vsi = np->vsi;
+ struct i40e_pf *pf = vsi->back;
struct i40e_ring *ring;
+ if (test_bit(__I40E_CONFIG_BUSY, pf->state))
+ return -ENETDOWN;
+
if (test_bit(__I40E_VSI_DOWN, vsi->state))
return -ENETDOWN;
--
2.20.1
