[PATCH V2 2/6] powerpc/powernv: simplify the calculation of iov resource

Wei Yang weiyang at linux.vnet.ibm.com
Wed Aug 5 11:24:59 AEST 2015


The alignment of IOV BAR on PowerNV platform is the total size of the IOV
BAR. No matter whether the IOV BAR is truncated or not, the total size
could be calculated by (vfs_expanded * VF 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>
---
 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 9b41dba..7192e62 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.
+	 */
 	align = pci_iov_resource_size(pdev, resno);
 	if (pdn->vfs_expanded)
 		return pdn->vfs_expanded * align;
-- 
1.7.9.5



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