[PATCH V5 2/6] powerpc/powernv: simplify the calculation of iov resource alignment

[Gavin Shan]

On Fri, Oct 09, 2015 at 10:46:52AM +0800, Wei Yang wrote:
>The alignment of IOV BAR on PowerNV platform is the total size of the IOV
>BAR. No matter whether the IOV BAR is extended with number of
>roundup_pow_of_two(total_vfs) or number of max PE number (256), the total
>size could be calculated by (vfs_expanded * VF_BAR_size).
>
>This patch simplifies the pnv_pci_iov_resource_alignment() by removing the
>first case.
>
>Signed-off-by: Wei Yang <weiyang at linux.vnet.ibm.com>
>Reviewed-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>Acked-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 8c031b5..7da476b 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -2988,17 +2988,21 @@ static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
> 						      int resno)
> {
> 	struct pci_dn *pdn = pci_get_pdn(pdev);
>-	resource_size_t align, iov_align;
>-
>-	iov_align = resource_size(&pdev->resource[resno]);
>-	if (iov_align)
>-		return iov_align;
>+	resource_size_t align;
>
>+	/*
>+	 * On PowerNV platform, IOV BAR is mapped by M64 BAR to enable the
>+	 * SR-IOV. While from hardware perspective, the range mapped by M64
>+	 * BAR should be size aligned.
>+	 *
>+	 * This function returns the total IOV BAR size if M64 BAR is in
>+	 * Shared PE mode or just the individual size if not.
>+	 */

s/the invidial size/VF BAR size

> 	align = pci_iov_resource_size(pdev, resno);
>-	if (pdn->vfs_expanded)
>-		return pdn->vfs_expanded * align;
>+	if (!pdn->vfs_expanded)
>+		return align;
>
>-	return align;
>+	return pdn->vfs_expanded * align;

There is no difference before/after the changes. why this change is needed?

> }
> #endif /* CONFIG_PCI_IOV */
>
>-- 
>2.5.0
>