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 <schne...@linux.ibm.com>

With the fixes above and a few below:

Acked-by: Bjorn Helgaas <bhelg...@google.com>

> ---
>  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
> 

Reply via email to