nfp: register devlink after app is created

Devlink used to have two global locks: devlink lock and port lock,
our lock ordering looked like this:

  devlink lock -> driver's pf->lock -> devlink port lock

After recent changes port lock was replaced with per-instance
lock.  Unfortunately, new per-instance lock is taken on most
operations now.  This means we can only grab the pf->lock from
the port split/unsplit ops.  Lock ordering looks like this:

  devlink lock -> driver's pf->lock -> devlink instance lock

Since we can't take pf->lock from most devlink ops, make sure
nfp_apps are prepared to service them as soon as devlink is
registered.  Locking the pf must be pushed down after
nfp_app_init() callback.

The init order looks like this:
 nfp_app_init
 devlink_register
 nfp_app_start
 netdev/port_register

As soon as app_init is done nfp_apps must be ready to service
devlink-related callbacks.  apps can only register their own
devlink objects from nfp_app_start.

Fixes: 2406e7e546b2 ("devlink: Add per devlink instance lock")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 14 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.c b/drivers/net/ethernet/netronome/nfp/nfp_main.c
index 0953fa8f3109..c5b91040b12e 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -499,13 +499,9 @@ static int nfp_pci_probe(struct pci_dev *pdev,
 	if (err)
 		goto err_hwinfo_free;
 
-	err = devlink_register(devlink, &pdev->dev);
-	if (err)
-		goto err_hwinfo_free;
-
 	err = nfp_nsp_init(pdev, pf);
 	if (err)
-		goto err_devlink_unreg;
+		goto err_hwinfo_free;
 
 	pf->mip = nfp_mip_open(pf->cpp);
 	pf->rtbl = __nfp_rtsym_table_read(pf->cpp, pf->mip);
@@ -549,8 +545,6 @@ err_fw_unload:
 	kfree(pf->eth_tbl);
 	kfree(pf->nspi);
 	vfree(pf->dumpspec);
-err_devlink_unreg:
-	devlink_unregister(devlink);
 err_hwinfo_free:
 	kfree(pf->hwinfo);
 	nfp_cpp_free(pf->cpp);
@@ -571,18 +565,13 @@ err_pci_disable:
 static void nfp_pci_remove(struct pci_dev *pdev)
 {
 	struct nfp_pf *pf = pci_get_drvdata(pdev);
-	struct devlink *devlink;
 
 	nfp_hwmon_unregister(pf);
 
-	devlink = priv_to_devlink(pf);
-
-	nfp_net_pci_remove(pf);
-
 	nfp_pcie_sriov_disable(pdev);
 	pci_sriov_set_totalvfs(pf->pdev, 0);
 
-	devlink_unregister(devlink);
+	nfp_net_pci_remove(pf);
 
 	vfree(pf->dumpspec);
 	kfree(pf->rtbl);
@@ -598,7 +587,7 @@ static void nfp_pci_remove(struct pci_dev *pdev)
 	kfree(pf->eth_tbl);
 	kfree(pf->nspi);
 	mutex_destroy(&pf->lock);
-	devlink_free(devlink);
+	devlink_free(priv_to_devlink(pf));
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 }