From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Fri, 29 Jun 2018 15:09:00 -0500
Subject: nfp: stop limiting VFs to 0
Patch-mainline: v4.18-rc4
Git-commit: 83235822b8b4fe47ecbd6b6bcbcc902860ac00fc
References: bsc#1109837

Before 8d85a7a4f2c9 ("PCI/IOV: Allow PF drivers to limit total_VFs to 0"),
pci_sriov_set_totalvfs(pdev, 0) meant "we can enable TotalVFs virtual
functions".  After 8d85a7a4f2c9, it means "we can't enable *any* VFs".

That broke this scenario where nfp intends to remove any limit on the
number of VFs that can be enabled:

  nfp_pci_probe
    nfp_pcie_sriov_read_nfd_limit
      nfp_rtsym_read_le("nfd_vf_cfg_max_vfs", &err)
      pci_sriov_set_totalvfs(pf->pdev, 0)   # if FW didn't expose a limit

  ...
  # userspace writes N to sysfs "sriov_numvfs":
  sriov_numvfs_store
    pci_sriov_get_totalvfs                  # now returns 0
    return -ERANGE

Prior to 8d85a7a4f2c9, pci_sriov_get_totalvfs() returned TotalVFs, but it
now returns 0.

Remove the pci_sriov_set_totalvfs(pdev, 0) calls so we don't limit the
number of VFs that can be enabled.

Fixes: 8d85a7a4f2c9 ("PCI/IOV: Allow PF drivers to limit total_VFs to 0")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/nfp_main.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -240,7 +240,6 @@ static int nfp_pcie_sriov_read_nfd_limit
 		return pci_sriov_set_totalvfs(pf->pdev, pf->limit_vfs);
 
 	pf->limit_vfs = ~0;
-	pci_sriov_set_totalvfs(pf->pdev, 0); /* 0 is unset */
 	/* Allow any setting for backwards compatibility if symbol not found */
 	if (err == -ENOENT)
 		return 0;
@@ -668,7 +667,7 @@ static int nfp_pci_probe(struct pci_dev
 
 	err = nfp_net_pci_probe(pf);
 	if (err)
-		goto err_sriov_unlimit;
+		goto err_fw_unload;
 
 	err = nfp_hwmon_register(pf);
 	if (err) {
@@ -680,8 +679,6 @@ static int nfp_pci_probe(struct pci_dev
 
 err_net_remove:
 	nfp_net_pci_remove(pf);
-err_sriov_unlimit:
-	pci_sriov_set_totalvfs(pf->pdev, 0);
 err_fw_unload:
 	kfree(pf->rtbl);
 	nfp_mip_close(pf->mip);
@@ -715,7 +712,6 @@ static void nfp_pci_remove(struct pci_de
 	nfp_hwmon_unregister(pf);
 
 	nfp_pcie_sriov_disable(pdev);
-	pci_sriov_set_totalvfs(pf->pdev, 0);
 
 	nfp_net_pci_remove(pf);