On Thu, Aug 06, 2015 at 07:00:00PM +1000, Alexey Kardashevskiy wrote: >On 08/06/2015 02:51 PM, Gavin Shan wrote: >>On Wed, Aug 05, 2015 at 09:24:59AM +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 truncated or not, the total size >>>could be calculated by (vfs_expanded * VF size). >>> >> >>s/VF size/VF BAR size >> >>I think the changelog would be more explicit: >> >>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 max >>VFs or number of max PE number (256). The alignment can be calculated >>by (vfs_expaned * VF_BAR_size). > > > >Is that really a PowerNV-specific requirement or it is valid for >every platform (I suspect this is the case here)? >
Currently, it is PowerNV-specific. > >Also, what is the exact meaning of "expanded" in @vfs_expanded? It is >either 255 (if individual VF BARs are <= 64MB) or >roundup_pow_of_two(total_vfs) (which is something like 4 or 16). What >is expanded here? > PF's IOV BAR original size is (VF BAR size * total_vfs). After expanding, the IOV BAR size is (VF BAR size * 256) or (VF BAR size * roundup_pow_of_two(total_vfs)). > >> >>>This patch simplifies the pnv_pci_iov_resource_alignment() by removing the >>>first case. >>> >>>Signed-off-by: Wei Yang <weiy...@linux.vnet.ibm.com> >> >>Reviewed-by: Gavin Shan <gws...@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 >>> >> > > >-- >Alexey -- Richard Yang Help you, Help me _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev