net/mlx4_core: Defer VF initialization till PF is fully initialized

Fix in commit [1] is not sufficient since a deferred VF initialization
could happen after pci_enable_sriov() is finished, but before the PF is
fully initialized.
Need to prevent VFs from initializing till the PF is fully ready and
comm channel is operational.

[1] - 9798935 "net/mlx4_core: mlx4_init_slave() shouldn't access comm
      channel before PF is ready"

CC: Stuart Hayes <Stuart_Hayes@Dell.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 4b86c7af2a7a..cef267e24f9c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -2369,10 +2369,10 @@ static int __mlx4_init_one(struct pci_dev *pdev, int pci_dev_data)
                         } else {
                                 atomic_inc(&pf_loading);
                                 err = pci_enable_sriov(pdev, total_vfs);
-                                atomic_dec(&pf_loading);
                                 if (err) {
                                         mlx4_err(dev, "Failed to enable SR-IOV, continuing without SR-IOV (err = %d).\n",
                                                  err);
+                                        atomic_dec(&pf_loading);
                                         err = 0;
                                 } else {
                                         mlx4_warn(dev, "Running in master mode\n");
@@ -2532,6 +2532,9 @@ slave_start:
 
         priv->removed = 0;
 
+        if (mlx4_is_master(dev) && dev->num_vfs)
+                atomic_dec(&pf_loading);
+
         return 0;
 
 err_port:
@@ -2582,6 +2585,9 @@ err_rel_own:
         if (!mlx4_is_slave(dev))
                 mlx4_free_ownership(dev);
 
+        if (mlx4_is_master(dev) && dev->num_vfs)
+                atomic_dec(&pf_loading);
+
         kfree(priv->dev.dev_vfs);
 
 err_free_dev:
@@ -2675,6 +2681,7 @@ static void __mlx4_remove_one(struct pci_dev *pdev)
         if (dev->flags & MLX4_FLAG_SRIOV) {
                 mlx4_warn(dev, "Disabling SR-IOV\n");
                 pci_disable_sriov(pdev);
+                dev->num_vfs = 0;
         }
 
         if (!mlx4_is_slave(dev))