Re: [PATCH v2 1/2] pci: Call pcibios_sriov_enable() before IOV BARs are enabled

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Sep 30, 2016 at 09:47:49AM +1000, Gavin Shan wrote:
> In current implementation, pcibios_sriov_enable() is used by PPC
> PowerNV platform only. In PowerNV specific pcibios_sriov_enable(),
> PF's IOV BARs might be updated (shifted) by pci_update_resource().
> It means the IOV BARs aren't ready for decoding incoming memory
> address until pcibios_sriov_enable() returns.
> 
> This calls pcibios_sriov_enable() earlier before the IOV BARs are
> enabled. As the result, the IOV BARs have been configured correctly
> when they are enabled.
> 
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> Tested-by: Carol Soto <clsoto@us.ibm.com>
> ---
>  drivers/pci/iov.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 2194b44..f1343f0 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -303,13 +303,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
>  			return rc;
>  	}
>  
> -	pci_iov_set_numvfs(dev, nr_virtfn);
> -	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
> -	pci_cfg_access_lock(dev);
> -	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
> -	msleep(100);
> -	pci_cfg_access_unlock(dev);
> -
>  	iov->initial_VFs = initial;
>  	if (nr_virtfn < initial)
>  		initial = nr_virtfn;
> @@ -320,6 +313,13 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
>  		goto err_pcibios;
>  	}
>  
> +	pci_iov_set_numvfs(dev, nr_virtfn);
> +	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
> +	pci_cfg_access_lock(dev);
> +	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
> +	msleep(100);
> +	pci_cfg_access_unlock(dev);

This one looks fine to me.

>  	for (i = 0; i < initial; i++) {
>  		rc = pci_iov_add_virtfn(dev, i, 0);
>  		if (rc)
> -- 
> 2.1.0
> 
> --
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