Re: [PATCH v4 4/6] PCI: Rename dma_alias_is_enabled() to pci_devs_are_dma_aliases()

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 24 Feb 2016 13:44:15 -0600
Bjorn Helgaas <bhelgaas@google.com> wrote:

> This should be folded into the previous patch.  I left it separate to show
> the interface difference more clearly.
> 
> Also, pci_devs_are_dma_aliases() uses PCI internals (dma_alias_mask), so I
> think it should be in PCI code instead of in IOMMU code.  That would mean
> both it and pci_add_dma_alias() should probably be declared in
> include/linux/pci.h (but not exported to modules with EXPORT_SYMBOL()).
> ---
>  drivers/iommu/iommu.c |   11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)

Needs a Sign-off.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index a214e19..031d06b 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -659,10 +659,12 @@ static struct iommu_group *get_pci_function_alias_group(struct pci_dev *pdev,
>  	return NULL;
>  }
>  
> -static bool dma_alias_is_enabled(struct pci_dev *dev, u8 devfn)
> +static bool pci_devs_are_dma_aliases(struct pci_dev *pdev1, struct pci_dev *pdev2)
>  {
> -	return dev->dma_alias_mask &&
> -	       test_bit(devfn, dev->dma_alias_mask);
> +	return (pdev1->dma_alias_mask &&
> +		test_bit(pdev2->devfn, pdev1->dma_alias_mask)) ||
> +	       (pdev2->dma_alias_mask &&
> +		test_bit(pdev1->devfn, pdev2->dma_alias_mask));
>  }
>  
>  /*
> @@ -692,8 +694,7 @@ static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev,
>  			continue;
>  
>  		/* We alias them or they alias us */
> -		if (dma_alias_is_enabled(pdev, tmp->devfn) ||
> -		    dma_alias_is_enabled(tmp, pdev->devfn)) {
> +		if (pci_devs_are_dma_aliases(pdev, tmp)) {
>  			group = get_pci_alias_group(tmp, devfns);
>  			if (group) {
>  				pci_dev_put(tmp);
>