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authorAlexander Duyck <alexander.h.duyck@intel.com>2013-04-25 04:42:29 +0000
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2013-04-24 19:31:58 -0700
commit5a8eb24292ffd68604cedeb24ad2b4bc02cfc037 (patch)
treef85a264eccef0fec9337be43d8ff5fa5bac7a250 /drivers/pci
parentd44e7a9a1f1e56918f8e937dcf750626ac5ad9b4 (diff)
downloadlinux-5a8eb24292ffd68604cedeb24ad2b4bc02cfc037.tar.bz2
pci: Add SRIOV helper function to determine if VFs are assigned to guest
This function is meant to add a helper function that will determine if a PF has any VFs that are currently assigned to a guest. We currently have been implementing this function per driver, and going forward I would like to avoid that by making this function generic and using this helper. v2: Removed extern from declaration of pci_vfs_assigned in pci.h and return 0 if SR-IOV is disabled with is inline with other PCI SRIOV functions. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/iov.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee599f274f05..c93071d428f5 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -729,6 +729,47 @@ int pci_num_vf(struct pci_dev *dev)
EXPORT_SYMBOL_GPL(pci_num_vf);
/**
+ * pci_vfs_assigned - returns number of VFs are assigned to a guest
+ * @dev: the PCI device
+ *
+ * Returns number of VFs belonging to this device that are assigned to a guest.
+ * If device is not a physical function returns -ENODEV.
+ */
+int pci_vfs_assigned(struct pci_dev *dev)
+{
+ struct pci_dev *vfdev;
+ unsigned int vfs_assigned = 0;
+ unsigned short dev_id;
+
+ /* only search if we are a PF */
+ if (!dev->is_physfn)
+ return 0;
+
+ /*
+ * determine the device ID for the VFs, the vendor ID will be the
+ * same as the PF so there is no need to check for that one
+ */
+ pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id);
+
+ /* loop through all the VFs to see if we own any that are assigned */
+ vfdev = pci_get_device(dev->vendor, dev_id, NULL);
+ while (vfdev) {
+ /*
+ * It is considered assigned if it is a virtual function with
+ * our dev as the physical function and the assigned bit is set
+ */
+ if (vfdev->is_virtfn && (vfdev->physfn == dev) &&
+ (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED))
+ vfs_assigned++;
+
+ vfdev = pci_get_device(dev->vendor, dev_id, vfdev);
+ }
+
+ return vfs_assigned;
+}
+EXPORT_SYMBOL_GPL(pci_vfs_assigned);
+
+/**
* pci_sriov_set_totalvfs -- reduce the TotalVFs available
* @dev: the PCI PF device
* @numvfs: number that should be used for TotalVFs supported