On Wed, May 06, 2020 at 05:41:38PM +0200, Niklas Schnelle wrote:
> currently pci_iov_add_virtfn() scans the SR-IOV bars, adds the VF to the
> bus and also creates the sysfs links between the newly added VF and its
> parent PF.
s/currently/Currently/
s/bars/BARs/
> With pdev->no_vf_scan fencing off the entire pci_iov_add_virtfn() call
> s390 as the sole pdev->no_vf_scan user thus ends up missing these sysfs
> links which are required for example by QEMU/libvirt.
> Instead of duplicating the code introduce a new pci_iov_sysfs_link()
> function for establishing sysfs links.
This looks like two paragraphs missing the blank line between.
This whole thing is not "introducing" any new functionality; it's
"refactoring" to move existing functionality around and make it
callable separately.
> Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
With the fixes above and a few below:
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/iov.c | 36 ++++++++++++++++++++++++------------
> include/linux/pci.h | 8 ++++++++
> 2 files changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 4d1f392b05f9..d0ddf5f5484c 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -113,7 +113,6 @@ resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
> static void pci_read_vf_config_common(struct pci_dev *virtfn)
> {
> struct pci_dev *physfn = virtfn->physfn;
> -
> /*
> * Some config registers are the same across all associated VFs.
> * Read them once from VF0 so we can skip reading them from the
> @@ -133,12 +132,34 @@ static void pci_read_vf_config_common(struct pci_dev *virtfn)
> &physfn->sriov->subsystem_device);
> }
>
> +int pci_iov_sysfs_link(struct pci_dev *dev,
> + struct pci_dev *virtfn, int id)
> +{
> + int rc;
> + char buf[VIRTFN_ID_LEN];
Swap the order so these are declared in the order they're used below.
> + sprintf(buf, "virtfn%u", id);
> + rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
> + if (rc)
> + goto failed;
> + rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
> + if (rc)
> + goto failed1;
> +
> + kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
> +
> + return 0;
Add a blank link here to separate the "success" return from the error
paths.
> +failed1:
> + sysfs_remove_link(&dev->dev.kobj, buf);
> +failed:
> + return rc;
> +}
> +
> int pci_iov_add_virtfn(struct pci_dev *dev, int id)
> {
> int i;
> int rc = -ENOMEM;
> u64 size;
> - char buf[VIRTFN_ID_LEN];
> struct pci_dev *virtfn;
> struct resource *res;
> struct pci_sriov *iov = dev->sriov;
> @@ -182,23 +203,14 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
> }
>
> pci_device_add(virtfn, virtfn->bus);
> -
> - sprintf(buf, "virtfn%u", id);
> - rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
> + rc = pci_iov_sysfs_link(dev, virtfn, id);
> if (rc)
> goto failed1;
> - rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
> - if (rc)
> - goto failed2;
> -
> - kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
>
> pci_bus_add_device(virtfn);
>
> return 0;
>
> -failed2:
> - sysfs_remove_link(&dev->dev.kobj, buf);
> failed1:
> pci_stop_and_remove_bus_device(virtfn);
> pci_dev_put(dev);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 83ce1cdf5676..e97d27ac350a 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2048,6 +2048,8 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int id);
>
> int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
> void pci_disable_sriov(struct pci_dev *dev);
> +
> +int pci_iov_sysfs_link(struct pci_dev *dev, struct pci_dev *virtfn, int id);
> int pci_iov_add_virtfn(struct pci_dev *dev, int id);
> void pci_iov_remove_virtfn(struct pci_dev *dev, int id);
> int pci_num_vf(struct pci_dev *dev);
> @@ -2073,6 +2075,12 @@ static inline int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
> }
> static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
> { return -ENODEV; }
> +
> +static inline int pci_iov_sysfs_link(struct pci_dev *dev,
> + struct pci_dev *virtfn, int id)
Align the second line with the args in the first line, as the rest of
this file does.
> +{
> + return -ENODEV;
> +}
> static inline int pci_iov_add_virtfn(struct pci_dev *dev, int id)
> {
> return -ENOSYS;
> --
> 2.17.1
>
