Some user space depends on enabling sriov_totalvfs number of VFs
to not fail, e.g.:
$ cat .../sriov_totalvfs > .../sriov_numvfs
For devices which VF support depends on loaded FW we have the
pci_sriov_{g,s}et_totalvfs() API. However, this API uses 0 as
a special "unset" value, meaning drivers can't limit sriov_totalvfs
to 0. Remove the special values completely and simply initialize
driver_max_VFs to total_VFs. Then always use driver_max_VFs.
Add a helper for drivers to reset the VF limit back to total.
Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
---
drivers/net/ethernet/netronome/nfp/nfp_main.c | 6 +++---
drivers/pci/iov.c | 27 +++++++++++++++++++++------
include/linux/pci.h | 2 ++
3 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.c b/drivers/net/ethernet/netronome/nfp/nfp_main.c
index c4b1f344b4da..a76d177e40dd 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -123,7 +123,7 @@ static int nfp_pcie_sriov_read_nfd_limit(struct nfp_pf *pf)
return pci_sriov_set_totalvfs(pf->pdev, pf->limit_vfs);
pf->limit_vfs = ~0;
- pci_sriov_set_totalvfs(pf->pdev, 0); /* 0 is unset */
+ pci_sriov_reset_totalvfs(pf->pdev);
/* Allow any setting for backwards compatibility if symbol not found */
if (err == -ENOENT)
return 0;
@@ -537,7 +537,7 @@ static int nfp_pci_probe(struct pci_dev *pdev,
err_net_remove:
nfp_net_pci_remove(pf);
err_sriov_unlimit:
- pci_sriov_set_totalvfs(pf->pdev, 0);
+ pci_sriov_reset_totalvfs(pf->pdev);
err_fw_unload:
kfree(pf->rtbl);
nfp_mip_close(pf->mip);
@@ -570,7 +570,7 @@ static void nfp_pci_remove(struct pci_dev *pdev)
nfp_hwmon_unregister(pf);
nfp_pcie_sriov_disable(pdev);
- pci_sriov_set_totalvfs(pf->pdev, 0);
+ pci_sriov_reset_totalvfs(pf->pdev);
nfp_net_pci_remove(pf);
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 677924ae0350..c63ea870d8be 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -443,6 +443,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
iov->nres = nres;
iov->ctrl = ctrl;
iov->total_VFs = total;
+ iov->driver_max_VFs = total;
pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
iov->pgsz = pgsz;
iov->self = dev;
@@ -788,12 +789,29 @@ int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
}
EXPORT_SYMBOL_GPL(pci_sriov_set_totalvfs);
+/**
+ * pci_sriov_reset_totalvfs -- return the TotalVFs value to the default
+ * @dev: the PCI PF device
+ *
+ * Should be called from PF driver's remove routine with
+ * device's mutex held.
+ */
+void pci_sriov_reset_totalvfs(struct pci_dev *dev)
+{
+ /* Shouldn't change if VFs already enabled */
+ if (!dev->is_physfn || dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
+ return;
+
+ dev->sriov->driver_max_VFs = dev->sriov->total_VFs;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_reset_totalvfs);
+
/**
* pci_sriov_get_totalvfs -- get total VFs supported on this device
* @dev: the PCI PF device
*
- * For a PCIe device with SRIOV support, return the PCIe
- * SRIOV capability value of TotalVFs or the value of driver_max_VFs
+ * For a PCIe device with SRIOV support, return the value of driver_max_VFs
+ * which can be equal to the PCIe SRIOV capability value of TotalVFs or lower
* if the driver reduced it. Otherwise 0.
*/
int pci_sriov_get_totalvfs(struct pci_dev *dev)
@@ -801,9 +819,6 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev)
if (!dev->is_physfn)
return 0;
- if (dev->sriov->driver_max_VFs)
- return dev->sriov->driver_max_VFs;
-
- return dev->sriov->total_VFs;
+ return dev->sriov->driver_max_VFs;
}
EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 024a1beda008..95fde8850393 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1952,6 +1952,7 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id);
int pci_num_vf(struct pci_dev *dev);
int pci_vfs_assigned(struct pci_dev *dev);
int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
+void pci_sriov_reset_totalvfs(struct pci_dev *dev);
int pci_sriov_get_totalvfs(struct pci_dev *dev);
resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno);
void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool probe);
@@ -1978,6 +1979,7 @@ static inline int pci_vfs_assigned(struct pci_dev *dev)
{ return 0; }
static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
{ return 0; }
+static inline void pci_sriov_reset_totalvfs(struct pci_dev *dev) { }
static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
{ return 0; }
static inline resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
--
2.16.2
