Re: [PATCH 1/2] pci: Cache the VF device ID in the SR-IOV structure

[Bjorn Helgaas]

On Mon, Aug 28, 2017 at 03:38:49PM +0200, Filippo Sironi wrote:
> ... and use it instead of reading it over and over from the PF config
> space capability.
> 
> Signed-off-by: Filippo Sironi <sironi@xxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx

Applied to pci/virtualization for v4.15.

I renamed vf_did to vf_device for consistency with other existing fields.

> ---
>  drivers/pci/iov.c | 5 +++--
>  drivers/pci/pci.h | 1 +
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 120485d6f352..e8f7eafaba6a 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -134,7 +134,7 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id, int reset)
>  
>  	virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
>  	virtfn->vendor = dev->vendor;
> -	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
> +	virtfn->device = iov->vf_did;
>  	rc = pci_setup_device(virtfn);
>  	if (rc)
>  		goto failed0;
> @@ -448,6 +448,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
>  	iov->nres = nres;
>  	iov->ctrl = ctrl;
>  	iov->total_VFs = total;
> +	pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_did);
>  	iov->pgsz = pgsz;
>  	iov->self = dev;
>  	iov->drivers_autoprobe = true;
> @@ -723,7 +724,7 @@ int pci_vfs_assigned(struct pci_dev *dev)
>  	 * 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);
> +	dev_id = dev->sriov->vf_did;
>  
>  	/* loop through all the VFs to see if we own any that are assigned */
>  	vfdev = pci_get_device(dev->vendor, dev_id, NULL);
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 22e061738c6f..a7270e11e1ef 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -262,6 +262,7 @@ struct pci_sriov {
>  	u16 num_VFs;		/* number of VFs available */
>  	u16 offset;		/* first VF Routing ID offset */
>  	u16 stride;		/* following VF stride */
> +	u16 vf_did;		/* VF device ID */
>  	u32 pgsz;		/* page size for BAR alignment */
>  	u8 link;		/* Function Dependency Link */
>  	u8 max_VF_buses;	/* max buses consumed by VFs */
> -- 
> 2.7.4
>