From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Tue, 27 Jun 2017 00:50:25 -0700
Subject: nfp: handle SR-IOV already enabled when driver is probing
Patch-mainline: v4.13-rc1
Git-commit: 0dc78621918693face1700d1379c2b9f740282f5
References: bsc#1055968

We assumed that when we probe number of enabled VFs will be at 0.
This doesn't have to be the case for example if previous driver left
SR-IOV enabled due to some VFs being assigned.  Read the number of VFs
enabled.  Fail probe if it's above current FWs limit.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/nfp_main.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -414,6 +414,14 @@ static int nfp_pci_probe(struct pci_dev
 	if (err)
 		goto err_fw_unload;
 
+	pf->num_vfs = pci_num_vf(pdev);
+	if (pf->num_vfs > pf->limit_vfs) {
+		dev_err(&pdev->dev,
+			"Error: %d VFs already enabled, but loaded FW can only support %d\n",
+			pf->num_vfs, pf->limit_vfs);
+		goto err_fw_unload;
+	}
+
 	err = nfp_net_pci_probe(pf);
 	if (err)
 		goto err_sriov_unlimit;