Commit 21ca9fb6 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Leon Romanovsky
Browse files

PCI/IOV: Add pci_iov_vf_id() to get VF index 

The PCI core uses the VF index internally, often called the vf_id,
during the setup of the VF, eg pci_iov_add_virtfn().

This index is needed for device drivers that implement live migration
for their internal operations that configure/control their VFs.

Specifically, mlx5_vfio_pci driver that is introduced in coming patches
from this series needs it and not the bus/device/function which is
exposed today.

Add pci_iov_vf_id() which computes the vf_id by reversing the math that
was used to create the bus/device/function.

Link: https://lore.kernel.org/all/20220224142024.147653-2-yishaih@nvidia.com


Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarYishai Hadas <yishaih@nvidia.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
parent cfb92440

drivers/pci/iov.c

+14 −0
Original line number Diff line number Diff line
@@ -33,6 +33,20 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id) 
}

EXPORT_SYMBOL_GPL(pci_iov_virtfn_devfn);



int pci_iov_vf_id(struct pci_dev *dev)

{

	struct pci_dev *pf;



	if (!dev->is_virtfn)

		return -EINVAL;



	pf = pci_physfn(dev);

	return (((dev->bus->number << 8) + dev->devfn) -

		((pf->bus->number << 8) + pf->devfn + pf->sriov->offset)) /

	       pf->sriov->stride;

}

EXPORT_SYMBOL_GPL(pci_iov_vf_id);



/*

 * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may

 * change when NumVFs changes.

include/linux/pci.h

+7 −1
Original line number Diff line number Diff line
@@ -2166,7 +2166,7 @@ void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar); 
#ifdef CONFIG_PCI_IOV

int pci_iov_virtfn_bus(struct pci_dev *dev, int id);

int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);



int pci_iov_vf_id(struct pci_dev *dev);

int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);

void pci_disable_sriov(struct pci_dev *dev);
@@ -2194,6 +2194,12 @@ static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id) 
{

	return -ENOSYS;

}



static inline int pci_iov_vf_id(struct pci_dev *dev)

{

	return -ENOSYS;

}



static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)

{ return -ENODEV; }