[PATCH net 2/3] nfp: make sure representors are destroyed before their lower netdev

[Jakub Kicinski]

App start/stop callbacks can perform application initialization.
Unfortunately, flower app started using them for creating and
destroying representors.  This can lead to a situation where
lower vNIC netdev is destroyed while representors still try
to pass traffic.  This will most likely lead to a NULL-dereference
on the lower netdev TX path.

Move the start/stop callbacks, so that representors are created/
destroyed when vNICs are fully initialized.

Fixes: 5de73ee46704 ("nfp: general representor implementation")
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Simon Horman <simon.hor...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_main.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_main.c 
b/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
index 5797dbf2b507..1aca4e57bf41 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
@@ -456,10 +456,6 @@ static int nfp_net_pf_app_start(struct nfp_pf *pf)
 {
        int err;
 
-       err = nfp_net_pf_app_start_ctrl(pf);
-       if (err)
-               return err;
-
        err = nfp_app_start(pf->app, pf->ctrl_vnic);
        if (err)
                goto err_ctrl_stop;
@@ -484,7 +480,6 @@ static void nfp_net_pf_app_stop(struct nfp_pf *pf)
        if (pf->num_vfs)
                nfp_app_sriov_disable(pf->app);
        nfp_app_stop(pf->app);
-       nfp_net_pf_app_stop_ctrl(pf);
 }
 
 static void nfp_net_pci_unmap_mem(struct nfp_pf *pf)
@@ -559,7 +554,7 @@ static int nfp_net_pci_map_mem(struct nfp_pf *pf)
 
 static void nfp_net_pci_remove_finish(struct nfp_pf *pf)
 {
-       nfp_net_pf_app_stop(pf);
+       nfp_net_pf_app_stop_ctrl(pf);
        /* stop app first, to avoid double free of ctrl vNIC's ddir */
        nfp_net_debugfs_dir_clean(&pf->ddir);
 
@@ -690,6 +685,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 {
        struct nfp_net_fw_version fw_ver;
        u8 __iomem *ctrl_bar, *qc_bar;
+       struct nfp_net *nn;
        int stride;
        int err;
 
@@ -766,7 +762,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
        if (err)
                goto err_free_vnics;
 
-       err = nfp_net_pf_app_start(pf);
+       err = nfp_net_pf_app_start_ctrl(pf);
        if (err)
                goto err_free_irqs;
 
@@ -774,12 +770,20 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
        if (err)
                goto err_stop_app;
 
+       err = nfp_net_pf_app_start(pf);
+       if (err)
+               goto err_clean_vnics;
+
        mutex_unlock(&pf->lock);
 
        return 0;
 
+err_clean_vnics:
+       list_for_each_entry(nn, &pf->vnics, vnic_list)
+               if (nfp_net_is_data_vnic(nn))
+                       nfp_net_pf_clean_vnic(pf, nn);
 err_stop_app:
-       nfp_net_pf_app_stop(pf);
+       nfp_net_pf_app_stop_ctrl(pf);
 err_free_irqs:
        nfp_net_pf_free_irqs(pf);
 err_free_vnics:
@@ -803,6 +807,8 @@ void nfp_net_pci_remove(struct nfp_pf *pf)
        if (list_empty(&pf->vnics))
                goto out;
 
+       nfp_net_pf_app_stop(pf);
+
        list_for_each_entry(nn, &pf->vnics, vnic_list)
                if (nfp_net_is_data_vnic(nn))
                        nfp_net_pf_clean_vnic(pf, nn);
-- 
2.11.0