[Very RFC 08/46] powerpc/eeh: Calculate VF index rather than looking it up in pci_dn

[Alexey Kardashevskiy]

On 20/11/2019 12:28, Oliver O'Halloran wrote:
> Find the VF index based on the BDFN of the device rather than using a cached
> value in the pci_dn. This is probably slower than looking up the cached value
> in the pci_dn, but it's done infrequently (only in the EEH recovery path) and
> it's just arithmatic.
> 
> We need this here because the functions to remove a VF are slightly
> different to those which remove a physical PCI device.
> 
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>



Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>



> ---
>  arch/powerpc/kernel/eeh_driver.c | 44 +++++++++++++++++++++++++++-----
>  1 file changed, 37 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
> index a1eaffe868de..1cdeed464aed 100644
> --- a/arch/powerpc/kernel/eeh_driver.c
> +++ b/arch/powerpc/kernel/eeh_driver.c
> @@ -457,12 +457,35 @@ static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev,
>  	return rc;
>  }
>  
> +#ifdef CONFIG_PCI_IOV
> +/* FIXME: this should probably go in drivers/pci/iov.c */
> +static int eeh_find_vf_index(struct pci_dev *physfn, u16 vf_bdfn)
> +{
> +	u16 vf_bus, vf_devfn;
> +	int i;
> +
> +	vf_bus = vf_bdfn >> 8;
> +	vf_devfn = vf_bdfn & 0xff;
> +
> +	for (i = 0; i < pci_num_vf(physfn); i++) {
> +		if (pci_iov_virtfn_bus(physfn, i) != vf_bus)
> +			continue;
> +		if (pci_iov_virtfn_devfn(physfn, i) != vf_devfn)
> +			continue;
> +		return i;
> +	}
> +
> +	WARN_ON(1);
> +	return -1;
> +}
> +
>  static void *eeh_add_virt_device(struct eeh_dev *edev)
>  {
> -	struct pci_driver *driver;
>  	struct pci_dev *dev = eeh_dev_to_pci_dev(edev);
> +	struct pci_driver *driver;
> +	int vf_index;
>  
> -	if (!(edev->physfn)) {
> +	if (!edev->physfn) {
>  		eeh_edev_warn(edev, "Not for VF\n");
>  		return NULL;
>  	}
> @@ -476,11 +499,18 @@ static void *eeh_add_virt_device(struct eeh_dev *edev)
>  		eeh_pcid_put(dev);
>  	}
>  
> -#ifdef CONFIG_PCI_IOV
> -	pci_iov_add_virtfn(edev->physfn, eeh_dev_to_pdn(edev)->vf_index);
> -#endif
> +	vf_index = eeh_find_vf_index(edev->physfn, edev->bdfn);
> +	pci_iov_add_virtfn(edev->physfn, vf_index);
> +
>  	return NULL;
>  }
> +#else
> +static void *eeh_add_virt_device(struct eeh_dev *edev)
> +{
> +	WARN_ON(1);
> +	return NULL;
> +}
> +#endif
>  
>  static void eeh_rmv_device(struct eeh_dev *edev, void *userdata)
>  {
> @@ -521,9 +551,9 @@ static void eeh_rmv_device(struct eeh_dev *edev, void *userdata)
>  
>  	if (edev->physfn) {
>  #ifdef CONFIG_PCI_IOV
> -		struct pci_dn *pdn = eeh_dev_to_pdn(edev);
> +		int vf_index = eeh_find_vf_index(edev->physfn, edev->bdfn);
>  
> -		pci_iov_remove_virtfn(edev->physfn, pdn->vf_index);
> +		pci_iov_remove_virtfn(edev->physfn, vf_index);
>  		edev->pdev = NULL;
>  #endif
>  		if (rmv_data)
> 

-- 
Alexey