Re: [PATCH v3 2/6] powerpc/powernv: simplify the calculation of iov resource alignment

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Fri, Aug 14, 2015 at 11:04:58AM +1000, Gavin Shan wrote:
>On Thu, Aug 13, 2015 at 10:11:07PM +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@linux.vnet.ibm.com>
>>Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>---
>> arch/powerpc/platforms/powernv/pci-ioda.c |   14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>index 9ac324e..67b8f72 100644
>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>@@ -2987,12 +2987,16 @@ 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 return the total IOV BAR size if expanded or just the
>>+	 * individual size if not.
>>+	 */
>
>s/return/returns
>

Thanks :-)

>> 	align = pci_iov_resource_size(pdev, resno);
>> 	if (pdn->vfs_expanded)
>> 		return pdn->vfs_expanded * align;
>>-- 
>>1.7.9.5
>>

-- 
Richard Yang
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