From 5a8eb24292ffd68604cedeb24ad2b4bc02cfc037 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 25 Apr 2013 04:42:29 +0000 Subject: 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 Acked-by: Bjorn Helgaas Signed-off-by: Jeff Kirsher --- drivers/pci/iov.c | 41 +++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 5 +++++ 2 files changed, 46 insertions(+) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee599f274f0..c93071d428f 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -728,6 +728,47 @@ 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 diff --git a/include/linux/pci.h b/include/linux/pci.h index 710067f3618..43e45ac3645 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1644,6 +1644,7 @@ extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn); extern void pci_disable_sriov(struct pci_dev *dev); extern irqreturn_t pci_sriov_migration(struct pci_dev *dev); extern int pci_num_vf(struct pci_dev *dev); +int pci_vfs_assigned(struct pci_dev *dev); extern int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs); extern int pci_sriov_get_totalvfs(struct pci_dev *dev); #else @@ -1662,6 +1663,10 @@ static inline int pci_num_vf(struct pci_dev *dev) { return 0; } +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; -- cgit v1.2.3-70-g09d2