From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 005AA1A2D0C for ; Thu, 6 Aug 2015 19:41:08 +1000 (AEST) Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com [122.248.162.4]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 52C121402B7 for ; Thu, 6 Aug 2015 19:41:08 +1000 (AEST) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Aug 2015 15:11:06 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 2345E1258061 for ; Thu, 6 Aug 2015 15:14:14 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t769f4cD65732758 for ; Thu, 6 Aug 2015 15:11:04 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t769f3mi004647 for ; Thu, 6 Aug 2015 15:11:03 +0530 Date: Thu, 6 Aug 2015 17:41:02 +0800 From: Wei Yang To: Alexey Kardashevskiy Cc: Gavin Shan , Wei Yang , benh@kernel.crashing.org, linuxppc-dev@ozlabs.org Subject: Re: [PATCH V2 2/6] powerpc/powernv: simplify the calculation of iov resource Message-ID: <20150806094102.GB13055@richard> Reply-To: Wei Yang References: <20150731020148.GA6151@richard> <1438737903-10399-1-git-send-email-weiyang@linux.vnet.ibm.com> <1438737903-10399-3-git-send-email-weiyang@linux.vnet.ibm.com> <20150806045139.GB28524@gwshan> <55C32210.9090803@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <55C32210.9090803@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 >> >>Reviewed-by: Gavin Shan >> >>>--- >>>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