Re: [PATCH 12/15] powerpc/powernv/sriov: De-indent setup and teardown

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 10/07/2020 15:23, Oliver O'Halloran wrote:
> Remove the IODA2 PHB checks. We already assume IODA2 in several places so
> there's not much point in wrapping most of the setup and teardown process
> in an if block.
> 
> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
> ---
>  arch/powerpc/platforms/powernv/pci-sriov.c | 86 ++++++++++++----------
>  1 file changed, 49 insertions(+), 37 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci-sriov.c b/arch/powerpc/platforms/powernv/pci-sriov.c
> index 08f88187d65a..d5699cd2ab7a 100644
> --- a/arch/powerpc/platforms/powernv/pci-sriov.c
> +++ b/arch/powerpc/platforms/powernv/pci-sriov.c
> @@ -610,16 +610,18 @@ static void pnv_pci_sriov_disable(struct pci_dev *pdev)
>  	num_vfs = iov->num_vfs;
>  	base_pe = iov->vf_pe_arr[0].pe_number;
>  
> +	if (WARN_ON(!iov))
> +		return;
> +
>  	/* Release VF PEs */
>  	pnv_ioda_release_vf_PE(pdev);
>  
> -	if (phb->type == PNV_PHB_IODA2) {
> -		if (!iov->m64_single_mode)
> -			pnv_pci_vf_resource_shift(pdev, -base_pe);
> +	/* Un-shift the IOV BAR resources */
> +	if (!iov->m64_single_mode)
> +		pnv_pci_vf_resource_shift(pdev, -base_pe);
>  
> -		/* Release M64 windows */
> -		pnv_pci_vf_release_m64(pdev, num_vfs);
> -	}
> +	/* Release M64 windows */
> +	pnv_pci_vf_release_m64(pdev, num_vfs);
>  }
>  
>  static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
> @@ -693,41 +695,51 @@ static int pnv_pci_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
>  	phb = pci_bus_to_pnvhb(pdev->bus);
>  	iov = pnv_iov_get(pdev);
>  
> -	if (phb->type == PNV_PHB_IODA2) {
> -		if (!iov->vfs_expanded) {
> -			dev_info(&pdev->dev, "don't support this SRIOV device"
> -				" with non 64bit-prefetchable IOV BAR\n");
> -			return -ENOSPC;
> -		}
> +	/*
> +	 * There's a calls to IODA2 PE setup code littered throughout. We could
> +	 * probably fix that, but we'd still have problems due to the
> +	 * restriction inherent on IODA1 PHBs.
> +	 *
> +	 * NB: We class IODA3 as IODA2 since they're very similar.
> +	 */
> +	if (phb->type != PNV_PHB_IODA2) {
> +		pci_err(pdev, "SR-IOV is not supported on this PHB\n");
> +		return -ENXIO;
> +	}

or we could just skip setting

ppc_md.pcibios_sriov_enable = pnv_pcibios_sriov_enable;

for uninteresting platforms in pnv_pci_init_ioda_phb().


>  
> -		/* allocate a contigious block of PEs for our VFs */
> -		base_pe = pnv_ioda_alloc_pe(phb, num_vfs);
> -		if (!base_pe) {
> -			pci_err(pdev, "Unable to allocate PEs for %d VFs\n", num_vfs);
> -			return -EBUSY;
> -		}
> +	if (!iov->vfs_expanded) {
> +		dev_info(&pdev->dev, "don't support this SRIOV device"
> +			" with non 64bit-prefetchable IOV BAR\n");
> +		return -ENOSPC;
> +	}
>  
> -		iov->vf_pe_arr = base_pe;
> -		iov->num_vfs = num_vfs;
> +	/* allocate a contigious block of PEs for our VFs */
> +	base_pe = pnv_ioda_alloc_pe(phb, num_vfs);
> +	if (!base_pe) {
> +		pci_err(pdev, "Unable to allocate PEs for %d VFs\n", num_vfs);
> +		return -EBUSY;
> +	}
>  
> -		/* Assign M64 window accordingly */
> -		ret = pnv_pci_vf_assign_m64(pdev, num_vfs);
> -		if (ret) {
> -			dev_info(&pdev->dev, "Not enough M64 window resources\n");
> -			goto m64_failed;
> -		}
> +	iov->vf_pe_arr = base_pe;
> +	iov->num_vfs = num_vfs;
>  
> -		/*
> -		 * When using one M64 BAR to map one IOV BAR, we need to shift
> -		 * the IOV BAR according to the PE# allocated to the VFs.
> -		 * Otherwise, the PE# for the VF will conflict with others.
> -		 */
> -		if (!iov->m64_single_mode) {
> -			ret = pnv_pci_vf_resource_shift(pdev,
> -							base_pe->pe_number);
> -			if (ret)
> -				goto shift_failed;
> -		}
> +	/* Assign M64 window accordingly */
> +	ret = pnv_pci_vf_assign_m64(pdev, num_vfs);
> +	if (ret) {
> +		dev_info(&pdev->dev, "Not enough M64 window resources\n");
> +		goto m64_failed;
> +	}
> +
> +	/*
> +	 * When using one M64 BAR to map one IOV BAR, we need to shift
> +	 * the IOV BAR according to the PE# allocated to the VFs.
> +	 * Otherwise, the PE# for the VF will conflict with others.
> +	 */
> +	if (!iov->m64_single_mode) {
> +		ret = pnv_pci_vf_resource_shift(pdev,
> +						base_pe->pe_number);

This can be a single line now. Thanks,


> +		if (ret)
> +			goto shift_failed;
>  	}
>  
>  	/* Setup VF PEs */
> 

-- 
Alexey